@font-face {
  font-family: "Labbook Sans";
  src: url("/game/lesson7/fonts/PretendardVariable.woff2") format("woff2");
  font-weight: 100 900;
  font-display: swap;
}
:root {
  --green: #294d43;
  --deep: #203e36;
  --yellow: #f2cd57;
  --paper: #f7f7ef;
  --ink: #253b33;
  --muted: #647169;
  --line: #dce3d9;
  --soft: #e9eee4;
  --white: #fff;
  --accent: #866419;
  font-family: "Labbook Sans", "Malgun Gothic", sans-serif;
  color: var(--ink);
  background: var(--paper);
  font-synthesis: none;
}
* {
  box-sizing: border-box;
}
body {
  margin: 0;
}
button,
input,
textarea,
select {
  font: inherit;
  color: inherit;
}
button,
a,
input,
select {
  touch-action: manipulation;
}
button {
  cursor: pointer;
  border: 0;
  background: none;
}
button:disabled {
  opacity: 0.45;
  cursor: not-allowed;
}
button:focus-visible,
a:focus-visible {
  outline: 3px solid #9b751e;
  outline-offset: 4px;
}
a {
  color: var(--green);
}
h1,
h2,
h3,
p {
  margin: 0;
}
h1 {
  font-size: clamp(25px, 2.2vw, 34px);
  letter-spacing: -1.2px;
  line-height: 1.45;
}
h2 {
  font-size: 22px;
  letter-spacing: -0.6px;
  line-height: 1.5;
}
h3 {
  font-size: 17px;
}
p {
  line-height: 1.8;
}
small,
.small {
  font-size: 13px;
  line-height: 1.7;
}
.muted {
  color: var(--muted);
}
.row {
  display: flex;
  gap: 12px;
  align-items: center;
  flex-wrap: wrap;
}
.between {
  justify-content: space-between;
}
.stack {
  display: grid;
  gap: 20px;
}
.primary {
  background: var(--yellow);
  color: var(--deep);
  padding: 13px 21px;
  border-radius: 10px;
  font-weight: 700;
  min-height: 46px;
}
.secondary {
  background: white;
  border: 1px solid var(--line);
  padding: 11px 17px;
  border-radius: 10px;
  min-height: 44px;
}
.link {
  padding: 10px 0;
  color: var(--green);
  font-size: 14px;
}
.danger {
  color: #923c31;
}
.pill {
  display: inline-block;
  background: var(--soft);
  color: var(--green);
  padding: 6px 10px;
  border-radius: 6px;
  font-size: 12px;
  line-height: 1.5;
}
.coin {
  background: #fff5d2;
  color: var(--deep);
  padding: 9px 14px;
  border-radius: 24px;
  font-size: 14px;
  min-height: 44px;
}
.panel {
  background: white;
  border: 1px solid var(--line);
  border-radius: 17px;
  padding: 24px;
}
.panel > h2,
.panel > h3 {
  margin-bottom: 16px;
}
.shell {
  display: grid;
  grid-template-columns: 208px minmax(0, 1fr);
  min-height: 100vh;
}
.sidebar {
  background: var(--deep);
  color: #e0ebe3;
  padding: 32px 18px;
  position: sticky;
  top: 0;
  height: 100vh;
  display: flex;
  flex-direction: column;
  gap: 36px;
}
.brand {
  font-size: 23px;
  font-weight: 800;
  letter-spacing: -0.8px;
  line-height: 1.2;
}
.brand b {
  color: var(--yellow);
}
.brand small {
  display: block;
  font-size: 11px;
  letter-spacing: 1px;
  margin-top: 12px;
  font-weight: 500;
}
.sidebar nav {
  display: grid;
  gap: 8px;
}
.nav {
  display: flex;
  gap: 12px;
  align-items: center;
  padding: 14px;
  border-radius: 10px;
  color: inherit;
  text-align: left;
  font-size: 15px;
}
.nav.active {
  background: var(--yellow);
  color: var(--deep);
  font-weight: 700;
}
.nav svg {
  width: 20px;
  height: 20px;
}
.sidebar-note {
  margin-top: auto;
  border-top: 1px solid #557366;
  padding-top: 22px;
  color: #c1d1c4;
  font-size: 12px;
  line-height: 1.9;
}
.workspace {
  min-width: 0;
}
.topbar {
  padding: 23px 36px;
  display: flex;
  gap: 20px;
  align-items: center;
  justify-content: space-between;
  border-bottom: 1px solid var(--line);
  flex-wrap: wrap;
}
.avatar {
  width: 37px;
  height: 37px;
  background: #dfe8d8;
  border-radius: 50%;
  display: grid;
  place-items: center;
  font-weight: 700;
  font-size: 13px;
}
.main {
  max-width: 1440px;
  margin: auto;
  padding: 30px 36px 50px;
}
.welcome {
  margin-bottom: 25px;
}
.welcome p {
  margin-top: 8px;
  font-size: 14px;
  color: var(--muted);
}
.columns {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 290px;
  gap: 22px;
}
.hero {
  background: var(--green);
  color: white;
  padding: 34px;
  border-radius: 20px;
  min-height: 290px;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  gap: 24px;
}
.hero h2 {
  font-size: clamp(26px, 2.4vw, 36px);
  line-height: 1.5;
  letter-spacing: -1px;
  max-width: 690px;
  margin: 15px 0;
}
.hero p,
.hero small {
  color: #dce8df;
}
.hero .pill {
  background: #446456;
  color: #f0f4e8;
}
.progress {
  height: 7px;
  background: #dbe3d7;
  border-radius: 9px;
  overflow: hidden;
  margin: 12px 0;
}
.progress span {
  display: block;
  height: 100%;
  background: var(--green);
}
.hero .progress {
  background: #607c70;
}
.hero .progress span {
  background: var(--yellow);
}
.lesson-grid {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 10px;
  margin-top: 20px;
}
.lesson {
  border: 1px solid var(--line);
  border-radius: 11px;
  padding: 14px;
  text-align: left;
  background: #fbfcf8;
  min-height: 112px;
  display: flex;
  flex-direction: column;
  gap: 10px;
}
.lesson strong {
  font-size: 14px;
  line-height: 1.6;
}
.lesson.active {
  border-color: var(--green);
  background: var(--soft);
}
.lesson small {
  color: var(--muted);
}
.metric {
  padding: 16px 0;
  border-bottom: 1px solid var(--line);
}
.metric strong {
  font-size: 28px;
}
.concept-row {
  padding: 14px 0;
  border-bottom: 1px solid var(--line);
  font-size: 14px;
  display: flex;
  gap: 12px;
  justify-content: space-between;
}
.feedback {
  padding: 17px;
  background: var(--soft);
  border-radius: 10px;
  font-size: 14px;
  line-height: 1.8;
  white-space: pre-wrap;
}
.feedback + .feedback {
  margin-top: 12px;
}
.feedback small {
  display: block;
  color: var(--muted);
  margin-bottom: 5px;
}
.notice {
  background: var(--soft);
  border-radius: 10px;
  padding: 16px;
  font-size: 14px;
  line-height: 1.8;
}
.login {
  max-width: 1160px;
  margin: 7vh auto;
  display: grid;
  grid-template-columns: 1.25fr 1fr;
  border-radius: 25px;
  overflow: hidden;
  border: 1px solid var(--line);
  background: white;
}
.login-intro {
  background: var(--deep);
  color: white;
  padding: 64px;
  display: flex;
  flex-direction: column;
  gap: 40px;
}
.login-intro h1 {
  font-size: 39px;
}
.login-intro p {
  color: #dbe8dc;
}
.login-form {
  padding: 65px 48px;
  display: flex;
  flex-direction: column;
  justify-content: center;
  gap: 22px;
}
.signin {
  display: block;
  text-align: center;
  text-decoration: none;
  background: var(--green);
  color: white;
  padding: 14px;
  border-radius: 10px;
  font-weight: 700;
}
.guest-form {
  display: flex;
  flex-direction: column;
  gap: 10px;
  padding-top: 18px;
  border-top: 1px solid #0000001a;
}
.guest-fields {
  display: grid;
  grid-template-columns: 2fr 1fr;
  gap: 10px;
}
.guest-fields input {
  width: 100%;
  min-width: 0;
}
.goal {
  position: sticky;
  top: 0;
  z-index: 5;
  background: #f7f7effa;
  border-bottom: 1px solid var(--line);
  padding: 18px 30px;
  display: flex;
  align-items: flex-start;
  gap: 16px;
  line-height: 1.7;
}
.goal .pill {
  flex-shrink: 0;
}
.goal strong {
  font-size: 15px;
}
.study-main {
  padding: 26px 30px 45px;
  max-width: 1440px;
  margin: auto;
}
.study-layout {
  display: grid;
  grid-template-columns: 195px minmax(0, 1fr);
  gap: 24px;
}
.steps {
  display: grid;
  gap: 8px;
  align-content: start;
  position: sticky;
  top: 115px;
  height: fit-content;
}
.step {
  text-align: left;
  padding: 13px;
  background: #fff;
  border: 1px solid var(--line);
  border-radius: 8px;
  font-size: 14px;
}
.step.active {
  background: var(--green);
  color: white;
  border-color: var(--green);
}
.study {
  min-width: 0;
  background: white;
  border: 1px solid var(--line);
  border-radius: 17px;
  padding: 30px;
}
.study h2 {
  font-size: 27px;
  margin: 12px 0 20px;
}
.study h3 {
  margin: 24px 0 12px;
}
.study .nav-foot {
  border-top: 1px solid var(--line);
  margin-top: 28px;
  padding-top: 20px;
}
.choices {
  display: grid;
  gap: 10px;
  margin: 20px 0;
}
.choice {
  display: flex;
  gap: 12px;
  align-items: flex-start;
  border: 1px solid var(--line);
  border-radius: 10px;
  padding: 14px;
  min-height: 49px;
  font-size: 15px;
  line-height: 1.6;
}
.choice:has(input:checked) {
  background: var(--soft);
  border-color: var(--green);
}
input[type="radio"],
input[type="checkbox"] {
  width: 19px;
  height: 19px;
  accent-color: var(--green);
  flex-shrink: 0;
  margin-top: 3px;
}
label.field {
  display: grid;
  gap: 9px;
  font-size: 14px;
  margin: 18px 0;
}
input[type="text"],
input[type="number"],
textarea,
select {
  width: 100%;
  padding: 12px;
  border: 1px solid #bdcabc;
  border-radius: 8px;
  background: white;
  font-size: 16px;
  min-height: 46px;
}
textarea {
  min-height: 110px;
  resize: vertical;
  line-height: 1.8;
}
input[type="range"] {
  width: 100%;
  accent-color: var(--green);
  min-height: 36px;
}
.concept {
  padding: 22px 0;
  border-bottom: 1px solid var(--line);
}
.concept h3 {
  margin: 0 0 9px;
}
.concept p {
  max-width: 780px;
}
.sim {
  background: #f4f7f0;
  border: 1px solid var(--line);
  border-radius: 14px;
  padding: 22px;
  margin: 20px 0;
}
.sim-controls {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 16px;
}
.sim-output {
  background: white;
  border-radius: 10px;
  padding: 17px;
  margin: 16px 0;
  line-height: 1.8;
}
.sim svg.circuit {
  width: 100%;
  height: auto;
  max-height: 210px;
}
.circuit text {
  fill: var(--ink);
  font:
    14px "Noto Sans KR",
    sans-serif;
}
.observation-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 13px;
  margin-top: 18px;
}
.observation-table th,
.observation-table td {
  padding: 12px 8px;
  text-align: left;
  border-bottom: 1px solid var(--line);
  vertical-align: top;
  overflow-wrap: anywhere;
}
.graph {
  width: 100%;
  height: auto;
  max-height: 240px;
}
.graph text {
  font:
    12px "Noto Sans KR",
    sans-serif;
  fill: var(--ink);
}
.two {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 20px;
}
.quiz {
  border: 1px solid var(--line);
  padding: 22px;
  border-radius: 12px;
  margin: 18px 0;
}
.quiz h3 {
  margin: 14px 0;
}
.quiz-result {
  margin-top: 15px;
  padding: 12px;
  background: var(--soft);
  border-radius: 7px;
  font-size: 14px;
  line-height: 1.7;
}
.mindmap {
  margin-top: 24px;
}
.map-board {
  position: relative;
  height: 480px;
  border: 1px solid var(--line);
  border-radius: 12px;
  background-color: #fafcf6;
  background-image: radial-gradient(#dbe4d7 1px, transparent 1px);
  background-size: 20px 20px;
  overflow: hidden;
  margin: 18px 0;
  touch-action: none;
}
.map-board > svg {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  pointer-events: none;
}
.map-node {
  position: absolute;
  max-width: 145px;
  min-width: 80px;
  padding: 10px;
  background: var(--green);
  color: white;
  border-radius: 9px;
  font-size: 14px;
  touch-action: none;
  user-select: none;
  cursor: grab;
}
.map-node.selected {
  outline: 3px solid var(--yellow);
}
.palette {
  display: flex;
  gap: 8px;
  flex-wrap: wrap;
}
.palette button {
  background: var(--soft);
  padding: 9px 12px;
  border-radius: 7px;
  font-size: 13px;
  min-height: 44px;
}
.map-tools {
  display: grid;
  grid-template-columns: 1fr 1fr 1.2fr auto;
  gap: 9px;
  align-items: end;
}
.map-tools label {
  margin: 0;
}
.map-board svg text {
  fill: var(--ink);
  font-size: 13px;
  paint-order: stroke;
  stroke: #fafcf6;
  stroke-width: 5px;
  stroke-linejoin: round;
}
.certificate {
  background: #fffdf3;
  border: 2px solid var(--green);
  padding: 48px;
  text-align: center;
  border-radius: 14px;
  display: grid;
  gap: 20px;
}
.certificate h2 {
  font-size: 32px;
}
.certificate .seal {
  margin: auto;
  background: var(--green);
  color: var(--yellow);
  border-radius: 50%;
  width: 85px;
  height: 85px;
  display: grid;
  place-items: center;
  font-size: 25px;
  font-weight: 800;
}
.teacher-list {
  display: grid;
  gap: 12px;
}
.record-button {
  display: flex;
  gap: 20px;
  justify-content: space-between;
  width: 100%;
  text-align: left;
  padding: 18px;
  border: 1px solid var(--line);
  border-radius: 12px;
  background: white;
}
.teacher-detail {
  margin-top: 24px;
}
.answer-entry {
  border-bottom: 1px solid var(--line);
  padding: 18px 0;
  white-space: pre-wrap;
  font-size: 14px;
  line-height: 1.7;
}
.loading {
  padding: 80px;
  text-align: center;
}
.empty {
  padding: 26px;
  color: var(--muted);
  line-height: 1.8;
}
#toast {
  position: fixed;
  bottom: 25px;
  left: 50%;
  transform: translateX(-50%);
  z-index: 30;
  border-radius: 10px;
  padding: 12px 20px;
  background: var(--deep);
  color: white;
  max-width: min(90vw, 680px);
  font-size: 14px;
  display: none;
}
dialog {
  border: 1px solid var(--line);
  padding: 28px;
  border-radius: 15px;
  max-width: 540px;
  width: 90%;
  color: var(--ink);
}
dialog::backdrop {
  background: #16392db3;
}
dialog p {
  margin: 16px 0;
}
dialog form {
  margin-top: 20px;
}
#print-area {
  display: none;
}
.sheet h2 {
  font-size: 23px;
  margin: 15px 0;
}
.sheet p,
.sheet li {
  line-height: 1.7;
}
.sheet header {
  border-bottom: 2px solid var(--green);
  padding-bottom: 12px;
}
.sheet section {
  margin: 16px 0;
}
.sheet .print-feedback {
  font-size: 12px;
  line-height: 1.7;
  white-space: pre-wrap;
}
.sheet .print-label {
  font-size: 11px;
  color: var(--muted);
}
.sheet .certificate {
  padding: 32px;
}
.sheet .map-board {
  height: 190mm;
}
.save-status {
  font-size: 12px;
  color: var(--muted);
}
@media (min-width: 1600px) {
  .main {
    padding-top: 45px;
  }
  .hero {
    min-height: 320px;
  }
  .study {
    padding: 40px;
  }
}
@media (max-width: 1150px) {
  .shell {
    grid-template-columns: 168px 1fr;
  }
  .sidebar {
    padding: 24px 12px;
  }
  .brand {
    font-size: 20px;
  }
  .nav {
    font-size: 13px;
    padding: 13px 10px;
  }
  .main,
  .topbar {
    padding-left: 25px;
    padding-right: 25px;
  }
  .columns {
    grid-template-columns: 1fr;
  }
  .columns > .stack:last-child {
    grid-template-columns: repeat(3, 1fr);
  }
  .study-layout {
    grid-template-columns: 1fr;
  }
  .steps {
    position: static;
    grid-template-columns: repeat(3, 1fr);
  }
  .goal {
    padding: 14px 25px;
  }
  .lesson-grid {
    grid-template-columns: repeat(4, 1fr);
  }
  .map-tools {
    grid-template-columns: 1fr 1fr;
  }
}
@media (max-width: 850px) {
  .shell {
    grid-template-columns: 1fr;
  }
  .sidebar {
    position: static;
    height: auto;
    padding: 18px 22px;
    gap: 16px;
  }
  .sidebar .brand {
    font-size: 19px;
    display: flex;
    gap: 6px;
    align-items: baseline;
  }
  .sidebar .brand small,
  .sidebar-note {
    display: none;
  }
  .sidebar nav {
    display: flex;
    flex-wrap: wrap;
    gap: 5px;
  }
  .nav {
    padding: 10px 12px;
    font-size: 13px;
    min-height: 44px;
  }
  .topbar {
    padding: 17px 22px;
  }
  .main,
  .study-main {
    padding: 24px 22px;
  }
  .goal {
    top: 0;
  }
  .columns > .stack:last-child {
    grid-template-columns: 1fr 1fr;
  }
  .login {
    margin: 25px;
    grid-template-columns: 1fr;
  }
  .login-intro {
    padding: 35px;
    gap: 20px;
  }
  .login-intro h1 {
    font-size: 30px;
  }
  .login-form {
    padding: 35px;
  }
  .study {
    padding: 24px;
  }
  .lesson-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}
@media (max-width: 560px) {
  .columns > .stack:last-child,
  .two,
  .sim-controls {
    grid-template-columns: 1fr;
  }
  .hero {
    padding: 24px;
  }
  .main,
  .study-main {
    padding: 18px 14px;
  }
  .goal {
    padding: 14px;
    gap: 10px;
  }
  .goal strong {
    font-size: 13px;
  }
  .steps {
    grid-template-columns: repeat(2, 1fr);
  }
  .step {
    font-size: 13px;
    padding: 11px;
  }
  .study {
    padding: 19px;
  }
  .study h2 {
    font-size: 23px;
  }
  .panel {
    padding: 20px;
  }
  .map-board {
    height: 450px;
  }
  .map-node {
    max-width: 105px;
    min-width: 60px;
    font-size: 12px;
    padding: 8px;
  }
  .map-tools {
    grid-template-columns: 1fr 1fr;
  }
  .certificate {
    padding: 24px;
  }
  .certificate h2 {
    font-size: 25px;
  }
  .login {
    margin: 14px;
  }
  .login-intro,
  .login-form {
    padding: 25px;
  }
}
@media print {
  @page {
    size: A4 portrait;
    margin: 12mm;
  }
  body {
    background: white;
  }
  #app,
  #toast,
  dialog {
    display: none !important;
  }
  #print-area {
    display: block;
    color: #203e36;
  }
  #print-area .sheet {
    font-size: 11pt;
  }
  .sheet section {
    margin: 10px 0;
  }
  .sheet h2 {
    font-size: 16pt;
  }
  .sheet h3 {
    font-size: 12pt;
  }
  .sheet p,
  .sheet li {
    line-height: 1.55;
  }
  .sheet .map-board {
    height: 220mm;
    margin: 12px 0;
    break-inside: avoid;
  }
  .sheet .map-node {
    print-color-adjust: exact;
    -webkit-print-color-adjust: exact;
  }
  .sheet .certificate {
    margin-top: 20mm;
  }
  .sheet .pill {
    print-color-adjust: exact;
    -webkit-print-color-adjust: exact;
  }
  .no-print {
    display: none !important;
  }
}

.map-edge-label {
  position: absolute;
  transform: translate(-50%, -50%);
  font-size: 12px;
  max-width: 160px;
  background: #fafcf6e6;
  padding: 2px 4px;
  text-align: center;
  pointer-events: none;
  line-height: 1.4;
  overflow-wrap: anywhere;
}
.lesson-visual,
.lab-experiment {
  margin: 24px 0;
  border: 1px solid #d7e3d8;
  border-radius: 16px;
  background: #f7faf5;
  overflow: hidden;
}
.visual-heading {
  padding: 18px 22px;
  display: flex;
  gap: 15px;
  align-items: center;
  justify-content: space-between;
  border-bottom: 1px solid #dce6dc;
}
.study .visual-heading h3 {
  margin: 9px 0 0;
}
.visual-body {
  padding: 18px 22px;
}
.visual-caption {
  padding: 0 22px 20px;
  font-size: 14px !important;
  color: #5c7165;
}
.visual-controls {
  display: flex;
  gap: 12px;
  align-items: center;
  flex-wrap: wrap;
  margin: 15px 0;
}
.visual-controls .field {
  flex: 1;
  min-width: 190px;
  margin: 10px 0;
}
.apparatus-board {
  position: relative;
  width: 100%;
  aspect-ratio: 800/350;
  min-height: 300px;
  max-height: 420px;
  background: linear-gradient(180deg, #fff, #edf1e9);
  border: 1px solid #d2dccc;
  border-radius: 12px;
  overflow: hidden;
  box-shadow: inset 0 -20px 50px #e0e4d6;
}
.apparatus-wires {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  pointer-events: none;
}
.topology-hidden .apparatus-wires,
.topology-hidden .wire-connector {
  display: none;
}
.wire-base {
  fill: none;
  stroke: #5b7864;
  stroke-width: 7;
  stroke-linejoin: round;
  stroke-linecap: round;
}
.flow-line {
  fill: none;
  stroke: #f2c953;
  stroke-width: 4;
  stroke-dasharray: 3 20;
  opacity: 0;
}
.flowing .flow-line {
  opacity: 1;
  animation: current-flow 1.8s linear infinite;
}
.flowing.reverse .flow-line {
  animation-direction: reverse;
}
.apparatus-part {
  position: absolute;
  width: 18%;
  padding: 0;
  background: none;
  min-height: 80px;
  z-index: 2;
  touch-action: manipulation;
  isolation: isolate;
}
.apparatus-part:disabled {
  opacity: 1;
}
.apparatus-part img {
  display: block;
  position: relative;
  width: 100%;
  height: 115px;
  object-fit: contain;
  z-index: 2;
  mix-blend-mode: multiply;
}
.apparatus-part.battery {
  width: 22%;
}
.apparatus-part.battery img {
  height: 130px;
}
.apparatus-part.knife-switch {
  width: 23%;
}
.apparatus-part.knife-switch img {
  height: 85px;
}
.part-label {
  display: block;
  background: #ffffffe8;
  position: relative;
  z-index: 4;
  border-radius: 6px;
  font-size: 13px;
  padding: 3px 5px;
  font-weight: 600;
  white-space: nowrap;
}
.apparatus-part:not(:disabled):hover img {
  filter: drop-shadow(0 0 5px #f2ca52);
}
.apparatus-board.three-bulbs .bulb {
  width: 15%;
}
.apparatus-board.three-bulbs.parallel {
  min-height: 440px;
  max-height: none;
}
.battery-polarity {
  position: absolute;
  top: 20%;
  left: 15%;
  z-index: 4;
  background: #fff9;
  font-size: 18px;
  padding: 3px;
}
.bulb-glow {
  position: absolute;
  left: 10%;
  right: 10%;
  top: 0;
  height: 105px;
  border-radius: 50%;
  background: radial-gradient(
    ellipse,
    #fffbd8 0%,
    #ffd45c99 40%,
    #ffd45c00 70%
  );
  filter: blur(8px);
  z-index: 3;
  pointer-events: none;
  transition: opacity 0.18s ease;
}
.bulb.disconnected {
  opacity: 0.48;
}
.wire-connector {
  position: absolute;
  width: 95px;
  font-size: 12px;
  background: #fafdf8;
  border: 2px dashed #a3aca0;
  border-radius: 9px;
  padding: 10px 5px;
  z-index: 4;
}
.wire-connector.connected {
  border-style: solid;
  background: #eaf1e6;
}
.board-readout {
  position: absolute;
  top: 12px;
  right: 12px;
  display: grid;
  gap: 4px;
  text-align: right;
  background: #fffef6e8;
  border-radius: 8px;
  padding: 10px;
  font-size: 12px;
  color: #334b3e;
}
.board-readout b {
  font-size: 21px;
}
.board-direction {
  position: static;
  margin: 10px 0 0;
  font-size: 12px;
  background: #ffffffd9;
  padding: 5px;
  border-radius: 7px;
}
.electron-model,
.water-model,
.inline-measurement {
  padding: 18px;
  margin-top: 20px;
  background: #fff;
  border: 1px solid #dde6dc;
  border-radius: 12px;
}
.electron-model svg,
.water-model svg {
  display: block;
  width: 100%;
  max-height: 210px;
}
.electron {
  fill: #3e7b70;
  transform-box: fill-box;
  transform-origin: center;
  animation: electron-jitter 2s ease-in-out infinite;
  animation-delay: var(--delay);
}
.electron.drifting {
  animation: electron-drift 2s linear infinite;
  animation-delay: var(--delay);
}
.electron.reverse {
  animation-direction: reverse;
}
.electron-sign {
  font-size: 15px;
  fill: white;
  pointer-events: none;
}
.electron-model p,
.water-model p {
  font-size: 14px;
}
.water-model svg text {
  font-size: 16px;
  fill: #334b3e;
}
.water-stream {
  animation: water-flow 1s linear infinite;
}
.wire-section {
  border: 1px solid #d6dfd2;
  height: 60px;
  padding: 12px;
  border-radius: 10px;
  display: flex;
  align-items: center;
}
.wire-section div {
  height: var(--wire-thickness);
  width: var(--wire-length);
  background: #8baf9b;
  border-radius: 12px;
  transition:
    width 0.2s,
    height 0.2s;
}
.energy-comparison {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 22px;
}
.energy-card {
  display: grid;
  gap: 12px;
  padding: 22px;
  border: 1px solid #d6dfd2;
  border-radius: 12px;
  background: white;
  text-align: center;
}
.energy-fill {
  position: relative;
  margin: auto;
  width: 68px;
  height: 130px;
  border: 2px solid #9eb09a;
  border-radius: 12px;
  background: #f5f7ee;
  overflow: hidden;
}
.energy-fill i {
  position: absolute;
  bottom: 0;
  left: 0;
  width: 100%;
  background: #f2cd57;
  transition: height 0.5s ease;
}
.energy-card output {
  font-size: 24px;
  font-weight: 700;
}
.inline-measurement output {
  display: block;
  font-weight: 700;
  font-size: 18px;
}
.life-preview {
  display: grid;
  grid-template-columns: 1.3fr 1fr;
  gap: 22px;
  align-items: center;
}
.life-preview img {
  width: 100%;
  border-radius: 10px;
}
.life-preview b {
  font-size: 27px;
}
.life-preview p {
  margin-top: 15px;
}
.safety-result,
.hidden-circuit {
  padding: 20px;
  background: #eef2e9;
  border-radius: 10px;
  line-height: 1.8;
}
.hidden-circuit {
  min-height: 170px;
  display: grid;
  align-content: center;
  gap: 10px;
  text-align: center;
}
.lab-experiment #experiment-apparatus {
  padding: 20px;
}
.study-shell {
  grid-template-columns: minmax(0, 1fr) !important;
}
.study-shell > .sidebar {
  position: fixed;
  left: 0;
  top: 0;
  width: 235px;
  height: 100dvh;
  z-index: 60;
  transform: translateX(-100%);
  transition: transform 0.2s ease;
  box-shadow: 8px 0 28px #183a2633;
  overflow: auto;
}
.study-shell.menu-open > .sidebar {
  transform: translateX(0);
}
.study-shell > .sidebar nav {
  display: grid;
}
.study-shell > .sidebar .brand {
  display: block;
}
.study-shell > .sidebar .brand small,
.study-shell > .sidebar .sidebar-note {
  display: block;
}
.menu-trigger-edge {
  position: fixed;
  left: 0;
  top: 40%;
  z-index: 58;
  border-radius: 0 8px 8px 0;
  padding: 14px 8px;
  background: var(--green);
  color: #fff;
  writing-mode: vertical-rl;
  font-size: 13px;
  min-height: 75px;
  box-shadow: 0 2px 10px #24452b25;
}
.study-menu-toggle {
  min-width: 44px;
  min-height: 44px;
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 8px 13px;
  font-size: 14px;
  background: white;
}
.study-menu-backdrop {
  display: none;
  position: fixed;
  inset: 0;
  z-index: 59;
  background: #18382a35;
}
.study-shell.menu-open .study-menu-backdrop {
  display: block;
}
.study-shell .topbar {
  padding-top: 14px;
  padding-bottom: 14px;
}
.sidebar-close {
  align-self: flex-end;
  color: inherit;
  padding: 8px 12px;
  border: 1px solid #7e9384;
  border-radius: 8px;
  font-size: 14px;
}
.game-frame-wrap {
  margin: 20px 0;
  border: 1px solid var(--line);
  border-radius: 12px;
  overflow: hidden;
  background: #f9fbf4;
}
.game-frame-toolbar {
  padding: 13px 18px;
  display: flex;
  justify-content: space-between;
  gap: 10px;
  align-items: center;
  flex-wrap: wrap;
  background: #e9eee3;
}
.game-frame {
  width: 100%;
  height: 900px;
  border: 0;
  display: block;
  background: #fafdf7;
}
.game-frame-wrap.expanded {
  position: fixed;
  inset: 12px;
  margin: 0;
  z-index: 75;
  display: flex;
  flex-direction: column;
  box-shadow: 0 0 0 50px #193c2b88;
}
.game-frame-wrap.expanded .game-frame {
  height: 100%;
  flex: 1;
  min-height: 0;
}
.game-report {
  padding: 17px;
  display: grid;
  gap: 9px;
  background: #f3f8ef;
}
.game-plan textarea {
  min-height: 85px;
}
.visual-section-note {
  font-size: 14px;
  margin: 15px 0;
}
.lab-experiment {
  margin-top: 15px;
}
@keyframes current-flow {
  to {
    stroke-dashoffset: -46;
  }
}
@keyframes electron-drift {
  to {
    transform: translateX(43px);
  }
}
@keyframes electron-jitter {
  50% {
    transform: translate(3px, -2px);
  }
}
@keyframes water-flow {
  to {
    stroke-dashoffset: -44;
  }
}
@media (max-width: 850px) {
  .study-shell .sidebar {
    padding: 25px 18px;
    gap: 25px;
  }
  .apparatus-board {
    aspect-ratio: 800/400;
    min-height: 290px;
  }
  .apparatus-part img {
    height: 100px;
  }
  .apparatus-part.battery img {
    height: 110px;
  }
  .apparatus-part.knife-switch img {
    height: 75px;
  }
  .board-readout {
    font-size: 11px;
    padding: 6px;
  }
  .board-readout b {
    font-size: 18px;
  }
  .part-label {
    font-size: 12px;
  }
  .board-direction {
    font-size: 11px;
  }
  .visual-heading,
  .visual-body {
    padding: 16px;
  }
  .visual-caption {
    padding: 0 16px 16px;
  }
  .game-frame {
    height: 1000px;
  }
  .life-preview {
    grid-template-columns: 1fr;
  }
  .menu-trigger-edge {
    padding: 12px 5px;
  }
  .study-shell .study-main {
    padding-left: 22px;
  }
}
@media (max-width: 560px) {
  .apparatus-part img {
    height: 80px;
  }
  .apparatus-part.battery img {
    height: 90px;
  }
  .apparatus-part.knife-switch img {
    height: 65px;
  }
  .apparatus-board {
    min-height: 270px;
  }
  .wire-connector {
    width: 64px;
    font-size: 11px;
  }
  .energy-card {
    padding: 12px;
  }
  .visual-heading {
    flex-wrap: wrap;
  }
  .game-frame-wrap.expanded {
    inset: 0;
    border-radius: 0;
  }
  .game-frame {
    height: 1100px;
  }
}
@media (prefers-reduced-motion: reduce) {
  .flow-line,
  .electron,
  .water-stream {
    animation: none !important;
  }
  .study-shell > .sidebar {
    transition: none;
  }
  .energy-fill i {
    transition: none;
  }
}
@media print {
  .lesson-visual,
  .lab-experiment,
  .game-frame-wrap,
  .menu-trigger-edge {
    display: none !important;
  }
}
.circuit-lab {
  container-type: inline-size;
  color: #29483d;
  font-size: 16px;
}
.lab-view-controls {
  display: flex;
  flex-wrap: wrap;
  gap: 10px 22px;
  padding: 12px 0 18px;
}
.lab-view-controls label {
  display: flex;
  align-items: center;
  gap: 7px;
  min-height: 44px;
  cursor: pointer;
}
.lab-view-controls input {
  width: 19px;
  height: 19px;
  accent-color: #38624e;
}
.current-key:before,
.electron-key:before {
  content: "";
  display: inline-block;
  width: 9px;
  height: 9px;
  border-radius: 50%;
  margin-right: 7px;
  background: #b58920;
}
.electron-key:before {
  background: #298d8b;
}
.circuit-comparison-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 18px;
}
.analogy-card {
  min-width: 0;
  border: 1px solid #dce4d9;
  border-radius: 18px;
  background: #f9faf5;
  overflow: hidden;
}
.analogy-card header {
  padding: 16px 18px 0;
  display: block;
}
.analogy-card h4 {
  margin: 0 0 6px;
  font-size: 19px;
}
.analogy-card header > span {
  font-size: 13px;
  color: #69796d;
}
.water-scene {
  padding: 6px 12px 0;
}
.water-scene svg {
  display: block;
  width: 100%;
  aspect-ratio: 900/500;
  height: auto;
}
.water-label {
  font-size: 16px;
  fill: #35584d;
  font-weight: 600;
}
.water-pipe,
.water-pump-path {
  fill: none;
  stroke: #d4dfd7;
  stroke-width: 17;
  stroke-linejoin: round;
}
.water-flow-path,
.water-pump-flow {
  fill: none;
  stroke: #4f9e9c;
  stroke-width: 9;
  stroke-dasharray: 13 16;
  stroke-linejoin: round;
  opacity: 0.35;
}
.height-line {
  stroke: #467f74;
  stroke-width: 3;
}
.water-high {
  transition:
    y 0.4s,
    height 0.4s;
}
.circuit-lab[data-flowing="true"] .water-flow-path,
.circuit-lab[data-flowing="true"] .water-pump-flow {
  animation: water-flow var(--water-duration, 1.8s) linear infinite;
  opacity: 1;
}
.wheel-rotor {
  transform-box: fill-box;
  transform-origin: center;
}
.circuit-lab[data-flowing="true"] .wheel-rotor {
  animation: wheel-turn var(--wheel-duration, 3s) linear infinite;
}
@keyframes water-flow {
  to {
    stroke-dashoffset: -58;
  }
}
@keyframes wheel-turn {
  to {
    transform: rotate(360deg);
  }
}
.clip-board {
  position: relative;
  aspect-ratio: 900/500;
  margin-top: 8px;
  overflow: hidden;
  isolation: isolate;
  background: linear-gradient(160deg, #fff, #edf1e7);
}
.clip-circuit {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  overflow: visible;
}
.flex-cable {
  fill: none;
  stroke-width: 6;
  stroke-linecap: round;
  stroke-linejoin: round;
  filter: drop-shadow(0 1px 1px #0002);
}
.wire-end-marker {
  stroke: #fff;
  stroke-width: 2;
  pointer-events: none;
}
.cable-electron circle {
  fill: #3b9592;
  stroke: #fff;
  stroke-width: 1.5;
}
.cable-electron text {
  fill: #fff;
  font-size: 16px;
  font-weight: 700;
  pointer-events: none;
}
.cable-current {
  fill: none;
  stroke: #e3b534;
  stroke-width: 5;
  stroke-linecap: round;
  stroke-linejoin: round;
  filter: drop-shadow(0 1px 1px #775411);
}
.part-name {
  position: absolute;
  font-size: 12px;
  font-weight: 700;
  pointer-events: none;
  text-align: center;
  background: #ffffffe8;
  padding: 3px 8px;
  border-radius: 5px;
  white-space: nowrap;
  transform: translateX(-50%);
}
.name-a {
  left: 41.7%;
  top: 37%;
}
.name-b {
  left: 75%;
  top: 37%;
}
.name-battery {
  left: 18.5%;
  top: 88%;
}
.name-switch {
  left: 61.8%;
  top: 87%;
}
.battery-positive,
.battery-negative {
  position: absolute;
  top: 63%;
  font-size: 20px;
  font-weight: 800;
  pointer-events: none;
  text-shadow: 0 1px white;
}
.battery-positive {
  left: 9%;
}
.battery-negative {
  left: 27%;
}
.photo-switch {
  position: absolute;
  left: 50%;
  top: 55%;
  width: 24%;
  height: 26%;
  z-index: 1;
  background: transparent;
  border: 0;
  padding: 0;
  cursor: pointer;
}
.photo-switch:focus-visible {
  outline: 3px solid #b88c22;
  outline-offset: -3px;
}
.pin-layer,
.clip-layer {
  position: absolute;
  inset: 0;
  pointer-events: none;
}
.terminal-pin,
.cable-clip {
  position: absolute;
  transform: translate(-50%, -50%);
  width: 44px;
  height: 44px;
  min-height: 44px;
  padding: 0;
  border: 0;
  border-radius: 50%;
  background: transparent;
  pointer-events: auto;
  touch-action: none;
  cursor: grab;
}
.terminal-pin {
  z-index: 3;
  cursor: crosshair;
}
.terminal-pin i {
  display: block;
  width: 13px;
  height: 13px;
  margin: auto;
  border-radius: 50%;
  border: 2px solid #547565;
  background: #d9e5d8;
  box-shadow: 0 0 0 3px #ffffff95;
}
.terminal-pin[data-pin="bp"] i,
.terminal-pin[data-pin="a1"] i,
.terminal-pin[data-pin="b1"] i {
  background: #b95341;
}
.terminal-pin.selected i,
.terminal-pin.snap-target i {
  background: #f2cd57;
  box-shadow: 0 0 0 6px #f2cd5760;
  border-color: #785a16;
}
.terminal-pin:focus-visible,
.cable-clip:focus-visible {
  outline: 3px solid #b68a20;
  outline-offset: 2px;
}
.clip-layer {
  z-index: 4;
}
.cable-clip {
  z-index: 5;
}
.cable-clip.dragging {
  z-index: 10;
  cursor: grabbing;
  background: #f2cd5740;
}
.cable-clip:hover {
  background: #f2cd5728;
}
.water-status,
.circuit-status {
  font-size: 14px;
  line-height: 1.55;
  padding: 12px 16px;
  min-height: 65px;
  border-top: 1px solid #e2e8dd;
  margin-top: 6px;
}
.circuit-lab[data-short="true"] .circuit-status {
  background: #fff4d6;
}
.lab-action-bar {
  display: flex;
  flex-wrap: wrap;
  gap: 9px;
  margin: 16px 0;
}
.lab-action-bar button {
  font-size: 14px;
  min-height: 44px;
  padding: 9px 14px;
}
.lab-voltage {
  display: flex;
  align-items: center;
  gap: 7px;
  max-width: 470px;
  font-weight: 600;
  min-height: 44px;
  white-space: nowrap;
}
.lab-voltage input {
  flex: 1;
  min-width: 80px;
  margin-left: 12px;
  accent-color: #4a7255;
  height: 28px;
}
.clip-instruction {
  font-size: 14px;
  line-height: 1.65;
  margin: 10px 0;
  color: #53695d;
}
.lab-drag-status {
  font-size: 13px;
  min-height: 20px;
  color: #3b674d;
}
.wire-access {
  padding: 12px 0;
}
.wire-access summary {
  min-height: 32px;
  cursor: pointer;
}
.wire-row {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 12px;
  padding: 12px 0;
  border-top: 1px solid #e2e8dd;
}
.wire-row label {
  display: flex;
  gap: 8px;
  align-items: center;
  font-size: 13px;
}
.wire-row select {
  max-width: 220px;
  border: 1px solid #bacdbf;
  border-radius: 8px;
  background: white;
  color: #29483d;
  padding: 9px;
  min-height: 44px;
}
.wire-row button {
  font-size: 13px;
  padding: 9px 12px;
}
.analogy-table {
  width: 100%;
  border-collapse: collapse;
  table-layout: fixed;
  margin: 12px 0 24px;
  font-size: 14px;
  text-align: center;
}
.analogy-table caption {
  text-align: left;
  font-size: 15px;
  font-weight: 600;
  padding: 8px 0;
}
.analogy-table th,
.analogy-table td {
  padding: 10px 6px;
  border: 1px solid #d9e3d7;
  word-break: keep-all;
}
.analogy-table th {
  background: #e7eee1;
  width: 75px;
}
.electron-comparison h4 {
  font-size: 17px;
  margin: 12px 0;
}
.electron-compare-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 14px;
}
.microscope-panel {
  padding: 16px;
  border: 1px solid #d9e3d7;
  border-radius: 12px;
  background: #fff;
}
.microscope-panel b {
  font-size: 15px;
}
.microscope-panel p {
  font-size: 14px;
  line-height: 1.6;
  margin: 10px 0 0;
}
.micro-wire {
  position: relative;
  height: 74px;
  background: #eaf1eb;
  margin-top: 12px;
  overflow: hidden;
  border-radius: 7px;
  border-top: 2px solid #a3b9aa;
  border-bottom: 2px solid #a3b9aa;
}
.micro-electron {
  position: absolute;
  display: grid;
  place-items: center;
  width: 15px;
  height: 15px;
  border-radius: 50%;
  font-size: 14px;
  font-style: normal;
  line-height: 1;
  color: #fff;
  background: #3b9592;
  animation: micro-jitter 0.65s ease-in-out infinite alternate;
  animation-delay: var(--delay);
}
.microscope-panel.closed[data-energized="true"] .micro-electron {
  animation:
    micro-drift 3s linear infinite,
    micro-jitter 0.65s ease-in-out infinite alternate;
  animation-delay: var(--delay);
}
.microscope-panel.closed[data-reverse="true"] .micro-electron {
  animation-direction: reverse, alternate;
}
@keyframes micro-jitter {
  from {
    translate: 0 calc(-1 * var(--jitter));
  }
  to {
    translate: var(--jitter) var(--jitter);
  }
}
@keyframes micro-drift {
  from {
    transform: translateX(0);
  }
  to {
    transform: translateX(-48px);
  }
}
.analogy-limit {
  font-size: 13px;
  line-height: 1.7;
  color: #617063;
  background: #eff3e9;
  border-radius: 10px;
  padding: 14px;
  margin: 16px 0 0;
}
.lesson-visual[data-visual-phase="prediction"] .analogy-table,
.lesson-visual[data-visual-phase="prediction"] .electron-comparison,
.lesson-visual[data-visual-phase="prediction"] .analogy-limit,
.lesson-visual[data-visual-phase="prediction"] .wire-access,
.lesson-visual[data-visual-phase="prediction"] .lab-voltage,
.lesson-visual[data-visual-phase="prediction"]
  [data-lab-check="showComparison"],
.lesson-visual[data-visual-phase="prediction"]
  .lab-view-controls
  label:has([data-lab-check="showComparison"]) {
  display: none;
}
.lesson-visual[data-visual-phase="prediction"]
  .lab-action-bar
  [data-lab-action="add"],
.lesson-visual[data-visual-phase="prediction"]
  .lab-action-bar
  [data-lab-action="clear"],
.lesson-visual[data-visual-phase="prediction"]
  .lab-action-bar
  [data-lab-action="reset"] {
  display: none;
}
@container (max-width:760px) {
  .circuit-comparison-grid {
    grid-template-columns: 1fr;
  }
  .clip-board {
    max-height: 430px;
  }
  .water-scene svg {
    max-height: 340px;
  }
  .analogy-card header > span {
    font-size: 14px;
  }
  .part-name {
    font-size: 14px;
  }
}
@container (max-width:490px) {
  .electron-compare-grid {
    grid-template-columns: 1fr;
  }
  .analogy-table {
    font-size: 12px;
  }
  .analogy-table th {
    width: 50px;
  }
  .analogy-table td {
    padding: 8px 3px;
  }
  .part-name {
    font-size: 12px;
  }
}
@media (prefers-reduced-motion: reduce) {
  .circuit-lab * {
    animation: none !important;
    transition: none !important;
  }
}
@media print {
  .circuit-lab {
    display: none;
  }
}
.lesson1-static {
  margin: 20px 0;
  background: #f2f5ed;
  border: 1px solid #d6e0d3;
  border-radius: 16px;
  padding: 14px;
  text-align: center;
}
.lesson1-static svg {
  display: block;
  width: 100%;
  height: auto;
  max-height: 330px;
}
.lesson1-static figcaption {
  font-size: 14px;
  color: #536b5e;
  margin-top: 10px;
}
.circuit-only {
  grid-template-columns: 1fr;
}
.circuit-only .clip-board {
  max-height: 430px;
}
.circuit-lab[data-profile="water"] .analogy-table {
  table-layout: auto;
  max-width: 650px;
}
.circuit-lab[data-profile="water"] .analogy-table th {
  width: auto;
}
.lesson1-concepts {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 16px;
  margin: 24px 0;
}
.lesson1-concepts article {
  padding: 18px;
  background: #eef3e7;
  border-radius: 12px;
}
.lesson1-concepts h3 {
  margin: 0;
}
.lesson1-concepts p {
  margin-bottom: 0;
  line-height: 1.7;
}
.direction-prediction {
  background: #f3f6ee;
  padding: 18px;
  border-radius: 14px;
  margin: 20px 0;
}
.lesson1-review {
  margin-bottom: 24px;
}
.lesson1-review h3 {
  line-height: 1.6;
}
.history-comic {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 18px;
  margin-top: 24px;
}
.comic-panel {
  background: #fff;
  border: 1px solid #cddcc9;
  border-radius: 14px;
  overflow: hidden;
}
.comic-panel h3 {
  font-size: 17px;
  line-height: 1.5;
  margin: 0;
  padding: 14px 18px;
  background: #e7eee1;
}
.comic-art {
  position: relative;
  overflow: hidden;
  aspect-ratio: 768/512;
  background: #e5e9db;
}
.comic-art img {
  position: absolute;
  width: 200%;
  height: auto;
  max-width: none;
  left: 0;
  top: 0;
}
.comic-art[data-panel="1"] img,
.comic-art[data-panel="3"] img {
  left: -100%;
}
.comic-art[data-panel="2"],
.comic-art[data-panel="3"] {
  aspect-ratio: 768/330;
}
.comic-art[data-panel="2"] img,
.comic-art[data-panel="3"] img {
  top: -155.152%;
}
.comic-panel p {
  font-size: 16px;
  line-height: 1.75;
  padding: 0 18px;
  margin: 14px 0;
}
.comic-panel .comic-dialogue {
  font-weight: 600;
  background: #fff1c3;
  padding: 14px;
  border-radius: 12px;
  margin: 16px 16px 12px;
}
.direction-key {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin: 24px 0;
  background: #e8efe2;
  padding: 16px;
  border-radius: 12px;
  font-weight: 600;
}
.direction-key span:last-child {
  color: #2c7775;
}
.history-sources {
  padding: 10px 0;
  margin-top: 16px;
}
.history-sources a {
  color: #35624c;
}
.lesson1-concepts + label,
.lesson1-review + div {
  margin-top: 20px;
}
@media (max-width: 800px) {
  .history-comic,
  .lesson1-concepts {
    grid-template-columns: 1fr;
  }
  .comic-art {
    max-height: 330px;
  }
  .comic-art[data-panel="2"],
  .comic-art[data-panel="3"] {
    max-height: none;
  }
  .comic-panel p {
    font-size: 16px;
  }
}
.lesson6-flow {
  font-size: 16px;
  line-height: 1.75;
}
.l6-page-counter {
  font-size: 14px;
  color: var(--muted);
  margin-bottom: 12px;
}
.l6-pair {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 18px;
  margin: 22px 0;
}
.l6-device-card {
  border: 1px solid var(--line);
  border-radius: 15px;
  background: #f5f7f2;
  padding: 20px;
  min-width: 0;
  text-align: center;
}
.l6-device-image {
  display: block;
  width: 100%;
  height: 190px;
  object-fit: contain;
}
.study .l6-device-card h3 {
  margin: 14px 0 10px;
  font-size: 20px;
}
.l6-device-card dl {
  margin: 0;
  text-align: left;
  display: grid;
  gap: 10px;
}
.l6-device-card dl > div {
  display: flex;
  justify-content: space-between;
  gap: 8px;
  flex-wrap: wrap;
}
.l6-device-card dt {
  font-size: 14px;
  color: var(--muted);
}
.l6-device-card dd {
  margin: 0;
  font-size: 21px;
  font-weight: 750;
}
.l6-device-card dd span {
  font-size: 16px;
}
.l6-card-button {
  padding: 0;
  background: var(--soft);
  border-radius: 16px;
  border: 2px solid transparent;
  overflow: hidden;
}
.l6-card-button:hover,
.l6-card-button:focus-visible {
  border-color: var(--green);
}
.l6-card-button .l6-device-card {
  border: 0;
  border-radius: 0;
}
.l6-card-choose {
  display: block;
  background: var(--green);
  color: white;
  padding: 12px;
  font-weight: 700;
}
.l6-equal {
  width: 100%;
  margin-bottom: 16px;
  min-height: 44px;
}
.l6-round-head {
  display: flex;
  flex-wrap: wrap;
  gap: 16px;
  justify-content: space-between;
  margin-top: 24px;
  color: var(--muted);
  font-size: 14px;
}
.l6-round-head strong {
  color: var(--green);
}
.l6-round-list {
  padding-left: 24px;
}
.l6-round-list li {
  padding: 13px;
  border-bottom: 1px solid var(--line);
}
.l6-round-list strong {
  display: block;
  font-size: 15px;
}
.l6-question-cards {
  display: grid;
  gap: 12px;
  margin: 24px 0;
}
.l6-question-cards blockquote {
  margin: 0;
  padding: 20px 24px;
  border-left: 5px solid var(--yellow);
  background: var(--soft);
  font-size: 20px;
}
.l6-success {
  line-height: 2.4;
  padding-left: 24px;
}
.l6-supply {
  width: 100%;
  height: auto;
  margin: 24px 0;
}
.l6-compact .l6-device-image {
  height: 130px;
}
.l6-power-model,
.l6-energy-model,
.l6-efficiency-model {
  background: #f6f8f3;
  border: 1px solid var(--line);
  border-radius: 14px;
  padding: 22px;
  margin: 20px 0;
}
.l6-scale-note {
  font-size: 14px;
  color: var(--muted);
  margin-bottom: 16px;
}
.l6-track {
  height: 28px;
  background: #e1e7dc;
  border-radius: 5px;
  overflow: hidden;
  position: relative;
}
.l6-track > span {
  height: 100%;
  display: block;
  background: var(--green);
}
.l6-track > span.monitor {
  background: #a27a19;
}
.l6-power-row {
  display: grid;
  grid-template-columns: 65px minmax(0, 1fr) 90px;
  gap: 12px;
  align-items: center;
  margin: 18px 0;
}
.l6-power-row output {
  font-size: 15px;
  text-align: right;
  font-weight: 700;
}
.l6-power-row [data-one-second] {
  width: 0;
}
.l6-second-active {
  animation: l6-second 1s linear forwards;
}
@keyframes l6-second {
  from {
    width: 0;
  }
  to {
    width: var(--final-width);
  }
}
.l6-formula {
  padding: 18px 22px;
  margin: 22px 0;
  background: var(--green);
  color: white;
  border-radius: 12px;
  font-weight: 750;
  text-align: center;
  font-size: 20px;
}
.l6-time-controls {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 18px;
}
.l6-time-controls section {
  border: 1px solid var(--line);
  padding: 18px;
  border-radius: 12px;
}
.l6-time-controls label {
  display: block;
  font-weight: 700;
}
.l6-time-controls output {
  display: block;
  font-size: 22px;
  margin: 5px 0;
}
.l6-time-controls input[type="range"] {
  width: 100%;
  height: 44px;
  accent-color: var(--green);
}
.l6-number-controls {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 8px;
}
.l6-number-controls input {
  width: 84px;
  min-width: 0;
  border: 1px solid var(--line);
  padding: 10px;
  border-radius: 8px;
  font-size: 18px;
}
.l6-number-controls label {
  font-size: 14px;
}
.l6-number-controls button {
  padding: 10px 16px;
  min-height: 44px;
}
.l6-presets {
  margin: 18px 0;
  gap: 10px;
  flex-wrap: wrap;
}
.l6-toggle {
  font-size: 14px;
  display: flex;
  align-items: center;
  gap: 10px;
  min-height: 44px;
}
.l6-energy-row {
  margin: 16px 0;
}
.l6-energy-row .row {
  gap: 10px;
  flex-wrap: wrap;
  margin-bottom: 8px;
}
.l6-energy-row output {
  font-size: 21px;
  font-weight: 750;
}
.l6-energy-row output small {
  font-size: 14px;
  color: var(--muted);
}
.l6-comparison {
  font-weight: 750;
  margin: 18px 0;
}
.l6-checklist {
  display: flex;
  flex-wrap: wrap;
  gap: 14px;
  margin: 18px 0;
  padding: 0;
  list-style: none;
  font-size: 14px;
}
.l6-observations,
.l6-evidence {
  font-size: 14px;
}
.l6-observations caption,
.l6-evidence caption {
  text-align: left;
  font-weight: 700;
  font-size: 16px;
  margin: 18px 0 8px;
}
.l6-conversion-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 20px;
  margin: 22px 0;
}
.l6-conversion-card {
  padding: 20px;
  border: 1px solid var(--line);
  border-radius: 15px;
  background: #f8faf5;
  min-width: 0;
}
.l6-working-device {
  position: relative;
}
.l6-working-device .l6-device-image {
  height: 150px;
}
.study .l6-conversion-card h3 {
  font-size: 19px;
  margin: 16px 0 8px;
}
.l6-node-buttons {
  display: flex;
  flex-wrap: wrap;
  gap: 7px;
  margin: 18px 0;
}
.l6-energy-node {
  border: 1px solid #9daf9b;
  border-radius: 8px;
  padding: 10px 12px;
  min-height: 44px;
  font-size: 14px;
  background: white;
}
.l6-energy-node.selected {
  background: var(--green);
  color: white;
  border-color: var(--green);
}
.l6-dropzone {
  padding: 12px;
  min-height: 72px;
  border: 1px dashed #91a88f;
  border-radius: 9px;
  margin-bottom: 14px;
  font-size: 14px;
}
.l6-conversion-note {
  margin-top: 16px;
  padding-top: 14px;
  border-top: 1px solid var(--line);
  font-size: 14px;
}
.l6-conversion-arrows {
  font-weight: 750;
  margin-top: 9px;
}
.l6-work-effect {
  position: absolute;
  right: 8px;
  top: 10px;
  border-radius: 50%;
  width: 32px;
  height: 32px;
  background: #f2cd57aa;
  box-shadow: 0 0 18px #f2cd57;
  pointer-events: none;
}
.effect-fan {
  border: 3px dashed #4e8873;
  background: none;
  animation: l6-spin 2s linear infinite;
}
.effect-speaker {
  border: 3px double #4e8873;
  background: none;
  animation: l6-pulse 1.4s ease-in-out infinite;
}
.effect-charging {
  background: #97bb89;
  border-radius: 6px;
  animation: l6-pulse 1.4s ease-in-out infinite;
}
@keyframes l6-spin {
  to {
    transform: rotate(360deg);
  }
}
@keyframes l6-pulse {
  50% {
    transform: scale(1.15);
    opacity: 0.65;
  }
}
.l6-lamp-scene {
  position: relative;
  isolation: isolate;
  background: #eef2e7;
  border: 1px solid var(--line);
  border-radius: 14px;
  padding: 20px;
  text-align: center;
  overflow: hidden;
}
.l6-light-pool {
  position: absolute;
  inset: 24% 10% 5%;
  z-index: -1;
  background: radial-gradient(ellipse at center, #ffe8a1aa, transparent 70%);
}
.l6-lamp-scene .l6-device-image {
  height: 175px;
}
.l6-lamp-scene strong,
.l6-lamp-scene span {
  display: block;
  margin-top: 10px;
}
.l6-lamp-scene span {
  font-size: 14px;
}
.l6-condition-checks {
  display: flex;
  flex-wrap: wrap;
  gap: 14px;
}
.l6-condition-checks label {
  min-height: 44px;
  display: flex;
  align-items: center;
  gap: 8px;
}
.l6-output-split {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 20px;
  align-items: center;
  margin: 20px 0;
}
.l6-output-split > span {
  border: 1px solid var(--line);
  padding: 16px;
  border-radius: 10px;
}
.l6-output-split > div {
  display: grid;
  gap: 8px;
  border-left: 3px solid #708c68;
  padding-left: 16px;
}
.l6-output-split strong,
.l6-output-split > div > span {
  padding: 12px;
  background: #ebefdf;
  border-radius: 8px;
}
.l6-output-split > div > span {
  background: #eee5d5;
}
.l6-label {
  width: 100%;
  max-width: 600px;
  height: auto;
  margin: 20px 0 8px;
}
.l6-efficiency-model > p {
  margin: 15px 0;
}
.l6-efficiency-model details {
  margin-top: 18px;
}
.l6-reflection .notice {
  margin: 0;
  overflow-wrap: anywhere;
}
.l6-concept-map {
  border: 1px solid var(--line);
  border-radius: 14px;
  padding: 24px;
  display: grid;
  justify-items: center;
  gap: 12px;
  margin: 24px 0;
  background: #f6f8f2;
  text-align: center;
}
.l6-input-nodes,
.l6-output-nodes {
  display: flex;
  gap: 14px;
  flex-wrap: wrap;
  justify-content: center;
}
.l6-input-nodes strong,
.l6-output-nodes strong,
.l6-output-nodes > span,
.l6-map-node {
  display: block;
  padding: 12px 20px;
  border: 1px solid #b7c5a9;
  border-radius: 9px;
  background: white;
}
.l6-input-nodes {
  position: relative;
  padding-bottom: 16px;
  border-bottom: 3px solid #91a488;
}
.l6-map-node {
  background: var(--green);
  color: white;
}
.l6-map-link {
  max-width: 100%;
  border-left: 2px solid #91a488;
  padding-left: 12px;
}
.l6-map-link select {
  max-width: 100%;
  width: 100%;
  min-height: 44px;
  padding: 10px;
  font-size: 14px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: white;
}
.l6-next-preview {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 20px;
  align-items: center;
  margin: 12px 0 30px;
}
.l6-next-preview img {
  width: 100%;
  border-radius: 12px;
}
.l6-print-notes {
  font-size: 10pt;
}
.lesson6-shell .steps {
  max-height: calc(100vh - 155px);
  overflow: auto;
}
.lesson6-shell .step {
  padding: 10px;
  font-size: 14px;
}
.lesson6-shell .study {
  min-height: 650px;
}
.lesson6-flow [hidden] {
  display: none !important;
}
.lesson6-flow .primary,
.lesson6-flow .secondary {
  min-height: 44px;
}
.lesson6-flow details p {
  margin: 12px 0;
}
.lesson6-flow input:focus-visible,
.lesson6-flow select:focus-visible,
.lesson6-flow textarea:focus-visible {
  outline: 3px solid #9b751e;
  outline-offset: 3px;
}
.lesson6-flow textarea {
  font-size: 16px;
}
.lesson6-flow .notice p {
  overflow-wrap: anywhere;
}
.l6-feedback-actions {
  margin: 14px 0;
}
.l6-initial-answer {
  margin-top: 15px;
  font-size: 14px;
  white-space: pre-wrap;
  overflow-wrap: anywhere;
}
@media (max-width: 1150px) {
  .lesson6-shell .steps {
    max-height: none;
    overflow: visible;
  }
  .lesson6-shell .step {
    font-size: 14px;
    padding: 10px;
  }
}
@media (max-width: 800px) {
  .l6-device-image {
    height: 150px;
  }
  .l6-device-card {
    padding: 15px;
  }
  .l6-device-card dd {
    font-size: 19px;
  }
  .l6-conversion-grid {
    grid-template-columns: 1fr;
  }
  .l6-reflection {
    grid-template-columns: 1fr;
  }
  .l6-next-preview {
    grid-template-columns: 1fr;
  }
  .l6-formula {
    font-size: 18px;
  }
  .l6-time-controls {
    gap: 12px;
  }
  .l6-time-controls section {
    padding: 12px;
  }
  .l6-number-controls button {
    padding: 9px 12px;
  }
  .l6-observations th,
  .l6-observations td,
  .l6-evidence th,
  .l6-evidence td {
    padding: 9px 5px;
  }
  .l6-concept-map {
    padding: 16px;
  }
}
@media (max-width: 560px) {
  .l6-pair,
  .l6-time-controls,
  .l6-output-split {
    grid-template-columns: 1fr;
  }
  .l6-device-card {
    display: grid;
    grid-template-columns: 95px 1fr;
    gap: 10px;
    text-align: left;
    align-items: center;
  }
  .l6-device-card .l6-device-image {
    grid-row: 1/3;
    height: 100px;
  }
  .study .l6-device-card h3 {
    margin: 0;
  }
  .l6-device-card dd {
    font-size: 17px;
  }
  .l6-device-card dl {
    grid-column: 2;
  }
  .l6-device-card dl > div {
    display: block;
  }
  .l6-device-card dt {
    display: inline;
    margin-right: 8px;
  }
  .l6-device-card dd {
    display: inline;
  }
  .l6-duel {
    gap: 10px;
  }
  .l6-card-choose {
    padding: 8px;
  }
  .l6-evidence,
  .l6-observations {
    font-size: 12px;
  }
  .l6-power-row {
    grid-template-columns: 55px minmax(0, 1fr) 75px;
    gap: 8px;
  }
}
@media (prefers-reduced-motion: reduce) {
  .l6-work-effect,
  .l6-second-active {
    animation: none !important;
  }
  .l6-second-active {
    width: var(--final-width) !important;
  }
}
@media print {
  .l6-print-notes p {
    line-height: 1.4;
  }
  .l6-print-notes h3 {
    margin-bottom: 5px;
  }
}
.lesson6-flow {
  font-family: "Labbook Sans", "Malgun Gothic", sans-serif;
  font-size: 20px;
  line-height: 1.8;
}
.lesson6-flow h2 {
  font-size: 32px;
  letter-spacing: -0.025em;
}
.lesson6-flow .small,
.lesson6-flow .muted,
.lesson6-flow .pill {
  font-size: 17px;
}
.lesson6-flow h3 {
  font-size: 24px;
}
.lesson6-flow .notice {
  padding: 24px;
}
.lesson6-flow .notice strong {
  display: block;
  font-size: 24px;
}
.lesson6-flow .notice p {
  font-size: 20px;
  margin: 8px 0;
}
.lesson6-flow input,
.lesson6-flow select,
.lesson6-flow textarea {
  font-family: inherit;
}
.lesson6-flow .choices .choice {
  font-size: 20px;
  padding: 18px;
}
.lesson6-flow .secondary,
.lesson6-flow .primary {
  font-size: 18px;
}
.lesson6-flow .l6-evidence,
.lesson6-flow .l6-observations {
  font-size: 18px;
}
.l6-writing {
  margin: 28px 0;
}
.l6-writing-head > label {
  display: block;
  font-size: 20px;
  font-weight: 650;
  margin-bottom: 10px;
}
.l6-writing > textarea,
.l6-round-list textarea {
  font-size: 19px;
  line-height: 1.7;
  display: block;
  width: 100%;
  min-height: 130px;
  border: 1px solid #a8b8a6;
  padding: 16px;
  border-radius: 12px;
  background: #fff;
  resize: vertical;
}
.l6-scaffold {
  margin-top: 12px;
  border: 1px solid var(--line);
  background: #f6f8f1;
  border-radius: 10px;
  padding: 12px 18px;
  font-size: 18px;
}
.l6-scaffold summary {
  cursor: pointer;
  color: var(--green);
  font-weight: 700;
  min-height: 32px;
}
.l6-sentence-frame {
  padding: 18px;
  border-left: 4px solid var(--yellow);
  background: white;
}
.l6-learning-goals {
  border: 2px solid var(--green);
  background: #f2f6ec;
  border-radius: 18px;
  padding: 26px;
  margin: 24px 0 28px;
}
.lesson6-flow .l6-learning-goals h3 {
  font-size: 27px;
  margin: 0 0 24px;
}
.l6-learning-goals ol {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 18px;
}
.l6-learning-goals li {
  display: flex;
  align-items: flex-start;
  gap: 18px;
}
.l6-learning-goals li > span {
  background: var(--green);
  color: white;
  width: 48px;
  height: 48px;
  border-radius: 12px;
  display: grid;
  place-items: center;
  flex-shrink: 0;
  font-weight: 750;
  font-size: 21px;
}
.l6-learning-goals strong {
  font-size: 24px;
  font-weight: 750;
  line-height: 1.5;
  display: block;
}
.l6-learning-goals p {
  font-size: 18px;
  margin: 7px 0 0;
  color: #4c6356;
}
.l6-inquiry-question {
  padding: 18px 22px;
  border: 1px solid var(--line);
  border-radius: 12px;
}
.lesson6-flow .l6-inquiry-question h3 {
  font-size: 20px;
  margin: 0 0 8px;
}
.l6-inquiry-question p {
  margin: 8px 0;
}
.l6-round-list {
  margin: 24px 0;
  list-style: decimal;
  padding-left: 30px;
}
.l6-round-list li {
  display: list-item;
  border-bottom: 1px solid var(--line);
  padding: 22px 12px;
}
.l6-round-list li > div {
  display: inline-block;
  vertical-align: top;
  width: 48%;
  padding-right: 16px;
}
.l6-round-list li > label {
  display: inline-block;
  vertical-align: top;
  width: 50%;
  font-size: 18px;
  font-weight: 650;
}
.l6-round-list p {
  margin: 0 0 8px;
}
.l6-round-list strong {
  font-size: 19px;
}
.l6-round-device {
  display: block;
}
.l6-round-device > strong {
  display: block;
  font-size: 22px;
}
.l6-round-device > span {
  display: block;
  font-size: 19px;
  margin-top: 4px;
}
.l6-round-vs {
  display: block;
  font-size: 16px;
  color: #52695b;
  margin: 8px 0;
}
.l6-fixed-conditions {
  margin: 24px 0;
  padding: 24px;
  background: #fff7d9;
  border-left: 5px solid #dbad27;
  border-radius: 12px;
}
.l6-fixed-conditions > strong {
  font-size: 24px;
}
.l6-fixed-conditions p {
  font-size: 22px;
  margin: 10px 0;
}
.l6-fixed-conditions > span {
  font-size: 19px;
}
.l6-efficiency-task {
  margin: 28px 0;
  padding: 24px;
  border: 1px solid #b3c3b1;
  border-radius: 16px;
  background: #fff;
}
.l6-task-heading {
  display: flex;
  gap: 16px;
  align-items: center;
}
.l6-task-heading > span {
  display: grid;
  place-items: center;
  width: 44px;
  height: 44px;
  flex-shrink: 0;
  border-radius: 10px;
  background: var(--green);
  color: white;
  font-size: 23px;
  font-weight: 750;
}
.lesson6-flow .l6-task-heading h3 {
  margin: 0;
  font-size: 26px;
  line-height: 1.45;
  word-break: keep-all;
}
.l6-task-note {
  margin: 12px 0 18px;
  font-size: 20px;
}
.l6-lamp-choice {
  display: block;
  cursor: pointer;
  border: 2px solid #aebeac;
}
.l6-lamp-choice:has(input:checked) {
  border: 3px solid var(--green);
  padding: 19px;
  background: #e9f1e1;
}
.l6-lamp-choice:has(input:focus-visible) {
  outline: 3px solid #b08619;
  outline-offset: 4px;
}
.l6-lamp-choice input {
  position: absolute;
  top: 18px;
  left: 18px;
  width: 26px;
  height: 26px;
  margin: 0;
  accent-color: var(--green);
}
.l6-lamp-choice strong {
  font-size: 27px;
}
.l6-lamp-choice span {
  font-size: 19px;
}
.l6-efficiency-task .l6-writing {
  margin: 20px 0 0;
}
.lesson6-flow .l6-compare-button {
  display: block;
  width: 100%;
  min-height: 70px;
  margin: 26px 0;
  padding: 20px 24px;
  font-size: 25px;
  line-height: 1.5;
  word-break: keep-all;
}
.l6-round-list textarea {
  margin-top: 8px;
  min-height: 100px;
  font-weight: 400;
}
.l6-supply-diagram {
  margin: 26px 0;
  padding: 22px;
  border: 1px solid var(--line);
  border-radius: 16px;
  background: #f8faf4;
  display: grid;
  grid-template-columns: minmax(100px, 1fr) 85px minmax(100px, 1fr) 75px minmax(
      180px,
      1.6fr
    );
  gap: 12px;
  align-items: center;
}
.l6-supply-node {
  background: white;
  border: 1px solid var(--line);
  border-radius: 14px;
  padding: 12px;
  text-align: center;
}
.l6-supply-node img {
  height: 125px;
  width: 100%;
  object-fit: contain;
}
.l6-supply-node strong {
  display: block;
  font-size: 23px;
}
.l6-flow-arrow {
  text-align: center;
}
.l6-flow-arrow span {
  display: block;
  font-size: 17px;
  line-height: 1.5;
  font-weight: 600;
  word-break: keep-all;
}
.lesson6-flow .l6-power-row {
  grid-template-columns: 90px minmax(0, 1fr) 100px;
}
.lesson6-flow .l6-power-row output {
  font-size: 18px;
}
.l6-flow-arrow b {
  display: block;
  font-size: 48px;
  line-height: 1.2;
  color: var(--green);
}
.l6-energy-thumbs {
  display: grid;
  gap: 8px;
  background: white;
  border: 1px solid var(--line);
  border-radius: 12px;
  padding: 12px;
}
.l6-energy-thumbs > div {
  display: flex;
  gap: 10px;
  align-items: center;
}
.l6-energy-thumbs .l6-device-image {
  height: 46px;
  width: 56px;
  flex-shrink: 0;
}
.l6-energy-thumbs span {
  font-size: 20px;
  font-weight: 600;
}
.l6-supply-diagram figcaption {
  grid-column: 1/-1;
  font-size: 17px;
  margin-top: 10px;
  color: #556a5c;
}
.l6-amount-formula {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 18px;
  flex-wrap: wrap;
  padding: 26px 20px;
  font-size: 25px;
}
.l6-amount-formula > span {
  display: block;
}
.l6-amount-formula strong {
  font-size: 29px;
}
.l6-amount-formula small {
  display: block;
  font-size: 16px;
  line-height: 1.45;
  font-weight: 450;
  margin-top: 7px;
}
.l6-unit-guide {
  padding: 24px;
  background: #faf5e4;
  border: 1px solid #d9cfa6;
  border-radius: 14px;
  margin: 24px 0;
}
.lesson6-flow .l6-unit-guide h3 {
  margin: 0 0 14px;
  font-size: 24px;
}
.l6-unit-guide p {
  margin: 12px 0;
  font-size: 19px;
}
.l6-unit-examples {
  display: flex;
  gap: 10px;
  flex-wrap: wrap;
}
.l6-unit-examples span {
  padding: 10px 14px;
  border-radius: 8px;
  background: white;
  border: 1px solid #e2d8ba;
  font-weight: 700;
}
.l6-instruction {
  border-left: 4px solid var(--green);
  padding: 14px 20px;
  background: #f0f4eb;
  font-size: 19px;
}
.l6-instructions {
  font-size: 19px;
  line-height: 1.8;
  background: #f3f6ee;
  border-radius: 12px;
  padding: 20px 24px 20px 48px;
}
.l6-concept-key {
  background: var(--green);
  color: white;
  padding: 24px;
  border-radius: 14px;
  margin: 24px 0;
}
.l6-concept-key strong {
  font-size: 26px;
}
.l6-map-v2 {
  display: grid;
  gap: 0;
  border: 1px solid var(--line);
  background: #f6f8f2;
  border-radius: 18px;
  margin: 28px 0;
  padding: 28px;
}
.l6-map-stage {
  width: 100%;
  max-width: 620px;
  margin: auto;
  text-align: center;
}
.l6-map-inputs {
  display: grid;
  grid-template-columns: 1fr 40px 1fr;
  gap: 10px;
  align-items: center;
}
.l6-map-inputs strong,
.l6-map-branch strong {
  display: block;
  border: 1px solid #b4c3ad;
  background: white;
  border-radius: 14px;
  padding: 18px;
  font-size: 23px;
}
.l6-map-v2 small {
  display: block;
  font-size: 17px;
  font-weight: 450;
}
.l6-map-main {
  display: block;
  margin: auto;
  max-width: 430px;
  background: var(--green);
  color: white;
  border-radius: 14px;
  padding: 20px;
  font-size: 26px;
}
.l6-map-connector {
  display: grid;
  justify-items: center;
  gap: 0;
  padding: 15px 0;
}
.l6-map-connector > b {
  font-size: 37px;
  color: #698675;
  line-height: 1.1;
  margin-top: 5px;
}
.l6-map-v2 select {
  font-family: inherit;
  max-width: 100%;
  width: auto;
  min-height: 48px;
  border: 1px solid #aebda4;
  border-radius: 9px;
  padding: 10px;
  font-size: 18px;
  background: white;
}
.l6-map-branch svg {
  width: 100%;
  height: 50px;
  display: block;
}
.l6-map-branch > div {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 24px;
}
.l6-map-branch strong:nth-child(2) {
  background: #eee8da;
}
.l6-map-efficiency {
  margin: 32px auto 0;
  border: 2px solid #8b9d77;
  border-radius: 16px;
  max-width: 620px;
  width: 100%;
  background: #fff;
  padding: 24px;
  text-align: center;
}
.lesson6-flow .l6-map-efficiency h3 {
  margin: 0 0 18px;
  font-size: 26px;
}
.l6-map-efficiency > div {
  display: grid;
  justify-items: center;
  gap: 7px;
  margin-bottom: 20px;
  font-size: 21px;
}
.l6-fraction-bar {
  height: 2px;
  width: 240px;
  max-width: 100%;
  background: var(--green);
}
.l6-map-efficiency p {
  font-size: 18px;
  margin-bottom: 0;
}
.l6-energy-row output small {
  font-size: 17px;
}
.lesson6-flow .l6-conversion-note,
.lesson6-flow .l6-dropzone {
  font-size: 18px;
}
.lesson6-flow .l6-energy-node {
  font-size: 17px;
}
.lesson6-shell .goal {
  position: static;
}
.lesson6-shell .goal strong {
  font-size: 17px;
}
.lesson6-shell .steps {
  top: 80px;
  max-height: calc(100vh - 105px);
}
.lesson6-shell .steps .step {
  font-size: 15px;
}
.lesson6-shell .l6-page-counter {
  font-size: 16px;
}
@media (max-width: 1150px) {
  .l6-supply-diagram {
    grid-template-columns: 1fr 65px 1fr;
  }
  .l6-flow-arrow:nth-child(4) {
    grid-column: 1/-1;
  }
  .l6-flow-arrow:nth-child(4) b {
    transform: rotate(90deg);
  }
  .l6-energy-thumbs {
    grid-column: 1/-1;
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }
  .l6-energy-thumbs > div {
    gap: 4px;
  }
  .l6-energy-thumbs .l6-device-image {
    width: 45px;
    height: 45px;
  }
  .l6-energy-thumbs span {
    font-size: 18px;
  }
  .lesson6-shell .steps {
    max-height: none;
    top: auto;
  }
  .l6-round-list li > div,
  .l6-round-list li > label {
    display: block;
    width: 100%;
  }
  .l6-round-list li > label {
    margin-top: 12px;
  }
}
@media (max-width: 800px) {
  .l6-efficiency-task {
    padding: 18px;
  }
  .lesson6-flow .l6-task-heading h3 {
    font-size: 23px;
  }
  .lesson6-flow .l6-compare-button {
    font-size: 22px;
  }
  .l6-lamp-choice strong {
    font-size: 23px;
  }
  .lesson6-flow {
    font-size: 19px;
  }
  .lesson6-flow h2 {
    font-size: 28px;
  }
  .l6-learning-goals {
    padding: 20px;
  }
  .l6-learning-goals strong {
    font-size: 22px;
  }
  .l6-learning-goals li {
    gap: 12px;
  }
  .l6-amount-formula {
    font-size: 21px;
    gap: 12px;
  }
  .l6-map-v2 {
    padding: 18px;
  }
  .l6-map-inputs strong,
  .l6-map-branch strong {
    font-size: 20px;
    padding: 16px 10px;
  }
  .l6-map-branch > div {
    gap: 14px;
  }
  .l6-energy-thumbs {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
  .lesson6-flow .l6-evidence,
  .lesson6-flow .l6-observations {
    font-size: 16px;
  }
  .l6-amount-formula strong {
    font-size: 25px;
  }
  .l6-supply-node img {
    height: 100px;
  }
  .l6-map-v2 select {
    font-size: 16px;
  }
  .lesson6-flow .l6-energy-node {
    font-size: 16px;
  }
}
@media (max-width: 560px) {
  .l6-supply-diagram {
    padding: 14px;
    gap: 8px;
    grid-template-columns: 1fr 45px 1fr;
  }
  .l6-supply-node {
    padding: 8px;
  }
  .l6-supply-node img {
    height: 80px;
  }
  .l6-supply-node strong {
    font-size: 20px;
  }
  .l6-flow-arrow span {
    font-size: 14px;
  }
  .l6-learning-goals li > span {
    width: 38px;
    height: 38px;
  }
  .l6-learning-goals strong {
    font-size: 20px;
  }
  .l6-learning-goals {
    padding: 16px;
  }
  .l6-amount-formula {
    gap: 10px;
    font-size: 19px;
  }
  .l6-amount-formula small {
    font-size: 14px;
  }
  .l6-map-v2 {
    padding: 12px;
  }
  .l6-map-efficiency {
    padding: 18px 12px;
  }
  .l6-unit-guide {
    padding: 18px;
  }
  .l6-round-list {
    padding-left: 23px;
  }
  .l6-round-list li {
    padding: 18px 0;
  }
}
/* Compact comparisons retain readable type and keep appliance conditions beside their image. */
.lesson6-flow .l6-mini-card {
  display: flex;
  align-items: center;
  gap: 8px;
  border: 1px solid #c9d4c4;
  border-radius: 12px;
  padding: 10px;
  background: #f5f7f2;
  min-width: 0;
  text-align: left;
}
.lesson6-flow .l6-mini-card.is-chosen {
  border: 2px solid var(--green);
  background: #e9f1e3;
  padding: 9px;
}
.lesson6-flow .l6-mini-card .l6-device-image {
  width: 72px;
  height: 86px;
  flex-shrink: 0;
}
.l6-mini-card > div {
  min-width: 0;
}
.l6-mini-card strong,
.l6-mini-card span {
  display: block;
  line-height: 1.45;
}
.l6-mini-card strong {
  font-size: 18px;
  word-break: keep-all;
}
.l6-mini-card span {
  font-size: 17px;
}
.l6-mini-duel {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 26px minmax(0, 1fr);
  gap: 6px;
  align-items: center;
}
.l6-mini-vs {
  font-size: 14px;
  text-align: center;
  color: #607468;
}
.l6-saved-choice {
  display: block;
  margin-top: 10px;
  font-size: 18px;
}
.l6-round-list li > div {
  width: 55%;
  padding-right: 20px;
}
.l6-round-list li > label {
  width: 44%;
  font-size: 19px;
  vertical-align: top;
  display: inline-block;
}
.l6-round-list textarea {
  min-height: 118px;
  margin-top: 8px;
}
.lesson6-flow .l6-power-comparison {
  display: grid;
  grid-template-columns: 230px minmax(0, 1fr);
  gap: 16px;
  margin: 14px 0;
}
.l6-power-devices {
  display: grid;
  gap: 10px;
}
.lesson6-flow .l6-power-model {
  margin: 0;
  padding: 16px;
  min-width: 0;
}
.lesson6-flow .l6-power-model h3 {
  margin: 0 0 6px;
  font-size: 23px;
}
.lesson6-flow .l6-power-model .l6-scale-note {
  margin-bottom: 8px;
}
.lesson6-flow .l6-power-row {
  grid-template-columns: 85px minmax(0, 1fr) 92px;
  margin: 12px 0;
  gap: 8px;
}
.lesson6-flow .l6-power-row .l6-track {
  height: 24px;
}
.l6-power-caption {
  display: flex;
  align-items: center;
  gap: 14px;
  flex-wrap: wrap;
}
.l6-power-caption p {
  flex: 1;
  margin: 0;
  font-size: 16px;
  line-height: 1.5;
  min-width: 150px;
}
.lesson6-flow.l6-layout-3 {
  line-height: 1.55;
}
.lesson6-flow.l6-layout-3 h2 {
  margin: 8px 0 10px;
}
.l6-layout-3 > p {
  margin: 8px 0;
}
.l6-layout-3 .pill {
  padding: 6px 12px;
}
.l6-layout-3 .l6-page-counter {
  margin-bottom: 6px;
}
.lesson6-flow .l6-power-definition {
  padding: 14px 18px;
  margin: 12px 0;
}
.lesson6-flow .l6-power-definition strong {
  font-size: 24px;
}
.lesson6-flow .l6-power-definition p {
  margin: 4px 0 0;
  font-size: 19px;
}
.l6-layout-3 .l6-supply-diagram {
  grid-template-columns: 100px 80px 100px 70px minmax(0, 1fr);
  gap: 8px;
  padding: 10px;
  margin: 10px 0;
}
.l6-layout-3 .l6-supply-node {
  padding: 4px;
  background: transparent;
  border: 0;
}
.l6-layout-3 .l6-supply-node img {
  height: 55px;
}
.l6-layout-3 .l6-supply-node strong {
  font-size: 18px;
}
.l6-layout-3 .l6-flow-arrow span {
  font-size: 15px;
}
.l6-layout-3 .l6-flow-arrow b {
  font-size: 26px;
}
.l6-layout-3 .l6-energy-thumbs {
  display: grid;
  grid-template-columns: repeat(5, minmax(0, 1fr));
  gap: 4px;
  padding: 4px;
  background: transparent;
  border: 0;
}
.l6-layout-3 .l6-energy-thumbs > div {
  display: flex;
  flex-direction: column;
  gap: 2px;
}
.l6-layout-3 .l6-energy-thumbs .l6-device-image {
  width: 40px;
  height: 44px;
}
.l6-layout-3 .l6-energy-thumbs span {
  font-size: 15px;
  white-space: nowrap;
}
.l6-layout-3 .l6-supply-diagram figcaption {
  font-size: 15px;
  margin: 0;
  line-height: 1.4;
}
.l6-layout-3 .l6-writing {
  margin: 12px 0;
}
.l6-layout-3 .l6-writing-head > label {
  margin-bottom: 6px;
}
.l6-layout-3 .l6-writing > textarea {
  min-height: 75px;
  padding: 10px 14px;
}
.l6-layout-3 .l6-scaffold {
  padding: 6px 12px;
  margin-top: 6px;
}
.l6-layout-3 .l6-scaffold summary {
  min-height: 26px;
}
.l6-layout-3 .secondary {
  padding: 10px 14px;
  min-height: 44px;
}
.l6-layout-4 .l6-amount-formula {
  margin: 12px 0;
  padding: 14px;
  line-height: 1.4;
}
.l6-layout-4 .l6-unit-guide {
  padding: 14px 18px;
  margin: 12px 0;
}
.lesson6-flow.l6-layout-4 .l6-unit-guide h3 {
  margin: 0 0 6px;
  font-size: 23px;
}
.l6-layout-4 .l6-unit-guide p {
  margin: 5px 0;
  font-size: 18px;
  line-height: 1.5;
}
.l6-layout-4 .l6-unit-examples {
  margin: 8px 0;
}
.l6-layout-4 .l6-instruction {
  margin: 12px 0;
  padding: 14px;
  font-size: 18px;
  line-height: 1.55;
}
.lesson6-flow .l6-time-device {
  display: flex;
  align-items: center;
  gap: 12px;
  margin-bottom: 8px;
}
.lesson6-flow .l6-time-device img {
  height: 78px;
  width: 85px;
}
.l6-time-device strong,
.l6-time-device span {
  display: block;
}
.l6-time-device strong {
  font-size: 22px;
}
.l6-time-device span {
  font-size: 18px;
}
.l6-layout-4 .l6-time-controls section {
  padding: 14px 18px;
}
.l6-layout-4 .l6-time-controls output {
  display: inline;
  margin: 0 0 0 10px;
  font-size: 23px;
}
.l6-layout-4 .l6-time-controls label {
  font-size: 18px;
  line-height: 1.5;
}
.l6-layout-4 .l6-number-controls {
  justify-content: center;
  gap: 12px;
}
.l6-layout-4 .l6-number-controls button {
  padding: 8px 16px;
  min-width: 44px;
  min-height: 44px;
}
.l6-layout-4 .l6-number-controls input {
  padding: 8px;
  min-height: 44px;
}
.l6-layout-4 .l6-presets {
  margin: 12px 0;
}
.l6-layout-4 .l6-energy-model {
  padding: 14px 18px;
  margin: 12px 0;
}
.lesson6-flow .l6-conversion-confirm {
  width: 100%;
  margin-top: 8px;
  background: #f4cd4d;
  color: #203f35;
  border: 2px solid #c9a029;
  font-weight: 750;
  box-shadow: 0 3px 0 #bd9522;
}
.lesson6-flow .l6-conversion-confirm:hover {
  background: #ffdf73;
}
.l6-lamp-conversions {
  display: grid;
  gap: 14px;
  margin: 18px 0;
}
.l6-lamp-conversion {
  padding: 16px;
  border: 1px solid var(--line);
  border-radius: 14px;
  background: white;
}
.l6-lamp-conversion h4 {
  margin: 0 0 10px;
  font-size: 23px;
}
.l6-conversion-path {
  display: grid;
  grid-template-columns: 170px 35px 120px minmax(0, 1fr);
  align-items: center;
  gap: 10px;
}
.l6-electric-input {
  background: #e5eee5;
  border: 1px solid #a7bda9;
  border-radius: 12px;
  padding: 14px;
  text-align: center;
}
.l6-electric-input strong,
.l6-electric-input span {
  display: block;
}
.l6-electric-input strong {
  font-size: 26px;
}
.l6-electric-input span {
  font-size: 17px;
}
.l6-diagram-arrow {
  font-size: 32px;
  color: var(--green);
  text-align: center;
}
.l6-diagram-lamp {
  text-align: center;
  font-size: 16px;
}
.lesson6-flow .l6-diagram-lamp img {
  height: 94px;
}
.l6-light-heat {
  display: grid;
  gap: 8px;
}
.l6-light-heat > div {
  display: grid;
  grid-template-columns: 36px 1fr;
  column-gap: 8px;
  align-items: center;
  padding: 8px 12px;
  border-radius: 10px;
  line-height: 1.5;
}
.l6-light-heat b {
  grid-row: 1/3;
  font-size: 36px;
}
.l6-light-heat strong {
  font-size: 21px;
}
.l6-light-heat span {
  font-size: 17px;
}
.l6-light-output {
  background: #fff2b9;
  color: #665416;
}
.l6-heat-output {
  background: #fae6dc;
  color: #79452e;
}
.l6-efficiency-definition {
  padding: 16px 18px;
  border-left: 5px solid var(--green);
  background: #eaf0e5;
  border-radius: 10px;
}
.l6-efficiency-definition > strong {
  font-size: 25px;
}
.l6-efficiency-definition p {
  margin: 8px 0;
  font-size: 20px;
}
.l6-official-label {
  display: grid;
  grid-template-columns: minmax(210px, 300px) minmax(0, 1fr);
  align-items: center;
  gap: 22px;
  background: white;
  border: 1px solid var(--line);
  border-radius: 14px;
  padding: 16px;
  margin: 20px 0;
}
.l6-official-label > img {
  width: 100%;
  height: auto;
}
.lesson6-flow .l6-official-label h3 {
  margin: 0;
  font-size: 23px;
}
.l6-official-label p {
  font-size: 18px;
  margin: 10px 0;
}
.l6-official-label a {
  font-size: 16px;
}
.l6-heater-help {
  padding: 14px 18px;
  border: 2px solid #8ba68a;
  border-radius: 12px;
  background: #fff;
  line-height: 1.6;
}
.l6-heater-help summary {
  font-size: 20px;
  font-weight: 700;
  cursor: pointer;
  color: var(--green);
}
.l6-heater-help p {
  margin: 12px 0 0;
}
@media (min-width: 1160px) {
  .lesson6-shell:has(.l6-layout-3) .study {
    padding: 20px 26px;
  }
  .lesson6-shell:has(.l6-layout-3) .study-main {
    padding-top: 16px;
  }
  .lesson6-shell:has(.l6-layout-3) .nav-foot {
    margin-top: 16px;
    padding-top: 14px;
  }
}
@media (max-width: 1150px) {
  .l6-round-list li > div,
  .l6-round-list li > label {
    display: block;
    width: 100%;
    padding-right: 0;
  }
  .l6-round-list li > label {
    margin-top: 12px;
  }
  .l6-mini-card .l6-device-image {
    width: 65px;
  }
  .l6-layout-3 .l6-supply-diagram {
    grid-template-columns: 85px 70px 85px 60px minmax(0, 1fr);
  }
  .l6-layout-3 .l6-energy-thumbs {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }
  .l6-layout-3 .l6-energy-thumbs > div {
    flex-direction: row;
  }
  .l6-layout-3 .l6-supply-diagram figcaption {
    grid-column: 1/-1;
  }
  .l6-conversion-path {
    grid-template-columns: 130px 30px 95px minmax(0, 1fr);
    gap: 8px;
  }
}
@media (max-width: 800px) {
  .lesson6-flow .l6-power-comparison {
    grid-template-columns: 180px minmax(0, 1fr);
    gap: 10px;
  }
  .lesson6-flow .l6-power-devices .l6-mini-card {
    gap: 4px;
    padding: 7px;
  }
  .lesson6-flow .l6-power-devices .l6-device-image {
    width: 50px;
    height: 70px;
  }
  .lesson6-flow .l6-power-row {
    grid-template-columns: 70px minmax(0, 1fr) 80px;
    font-size: 17px;
  }
  .l6-layout-3 .l6-supply-diagram {
    grid-template-columns: 85px 55px 85px;
  }
  .l6-layout-3 .l6-energy-thumbs {
    grid-column: 2/4;
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }
  .l6-layout-3 .l6-flow-arrow:nth-child(4) {
    grid-column: 1;
  }
  .l6-layout-3 .l6-energy-thumbs > div {
    flex-direction: column;
  }
  .l6-official-label {
    grid-template-columns: 230px minmax(0, 1fr);
    gap: 12px;
  }
}
@media (max-width: 560px) {
  .lesson6-flow .l6-mini-card {
    display: block;
    padding: 10px;
    text-align: center;
  }
  .lesson6-flow .l6-mini-card.is-chosen {
    padding: 9px;
  }
  .lesson6-flow .l6-mini-card .l6-device-image {
    width: 100%;
    height: 70px;
  }
  .l6-mini-card strong {
    font-size: 17px;
  }
  .l6-mini-card span {
    font-size: 16px;
  }
  .l6-mini-duel {
    grid-template-columns: minmax(0, 1fr) 22px minmax(0, 1fr);
  }
  .lesson6-flow .l6-power-comparison {
    grid-template-columns: 1fr;
  }
  .l6-power-devices {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
  .lesson6-flow .l6-power-devices .l6-device-image {
    width: 100%;
    height: 70px;
  }
  .lesson6-flow .l6-power-model {
    padding: 12px;
  }
  .l6-power-caption p {
    font-size: 16px;
  }
  .l6-layout-3 .l6-energy-thumbs {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
  .lesson6-flow .l6-power-definition strong {
    font-size: 21px;
  }
  .l6-layout-4 .l6-time-controls {
    grid-template-columns: 1fr;
  }
  .l6-conversion-path {
    grid-template-columns: 95px 24px minmax(0, 1fr);
    gap: 6px;
  }
  .l6-diagram-lamp {
    grid-column: 3;
  }
  .l6-light-heat {
    grid-column: 1/-1;
  }
  .l6-electric-input {
    padding: 10px;
  }
  .l6-electric-input strong {
    font-size: 23px;
  }
  .l6-electric-input span {
    font-size: 15px;
  }
  .l6-official-label {
    grid-template-columns: 1fr;
  }
  .l6-official-label > img {
    max-width: 290px;
    margin: auto;
  }
  .l6-heater-help summary {
    font-size: 19px;
  }
}
/* Keep the definition and the 100 W response together in a laptop viewport. */
.l6-layout-3 .l6-supply-node {
  display: flex;
  align-items: center;
  gap: 6px;
}
.l6-layout-3 .l6-supply-node img {
  display: block;
  width: 45px;
  height: 55px;
  flex-shrink: 0;
}
.l6-layout-3 .l6-supply-node strong {
  font-size: 17px;
  line-height: 1.3;
}
.l6-layout-3 .l6-supply-diagram {
  grid-template-columns: 110px 75px 110px 60px minmax(0, 1fr);
  padding: 8px;
  gap: 6px;
}
.l6-layout-3 .l6-flow-arrow span {
  font-size: 14px;
  line-height: 1.3;
}
.l6-layout-3 .l6-energy-thumbs .l6-device-image {
  height: 36px;
  width: 36px;
}
.l6-layout-3 .l6-energy-thumbs span {
  font-size: 14px;
  line-height: 1.4;
}
.l6-layout-3 .l6-supply-diagram figcaption {
  font-size: 14px;
}
.lesson6-flow .l6-power-definition {
  padding: 10px 16px;
}
.lesson6-flow .l6-power-definition strong {
  font-size: 23px;
  line-height: 1.4;
}
.lesson6-flow .l6-power-definition p {
  line-height: 1.45;
}
.lesson6-flow .l6-power-model {
  padding: 12px;
}
.lesson6-flow .l6-power-model h3 {
  line-height: 1.4;
  font-size: 23px;
}
.lesson6-flow .l6-power-model .l6-scale-note {
  font-size: 15px;
  line-height: 1.4;
  margin-bottom: 4px;
}
.lesson6-flow .l6-power-row {
  font-size: 18px;
  line-height: 1.4;
  margin: 8px 0;
}
.lesson6-flow .l6-power-devices .l6-device-image {
  height: 60px;
}
.l6-power-devices {
  gap: 8px;
}
.l6-power-caption {
  gap: 10px;
}
.lesson6-flow .l6-power-comparison {
  margin: 10px 0;
}
.l6-layout-4 .l6-time-controls label > small {
  display: block;
  margin-top: 4px;
  font-size: 16px;
  font-weight: 500;
}
.l6-usage-foundation {
  display: grid;
  grid-template-columns: minmax(0, 0.95fr) minmax(0, 1.3fr);
  gap: 14px;
  align-items: stretch;
  margin: 12px 0;
}
.l6-layout-4 .l6-usage-foundation .l6-amount-formula {
  margin: 0;
  align-content: center;
  gap: 10px;
  font-size: 23px;
}
.l6-layout-4 .l6-usage-foundation .l6-unit-guide {
  margin: 0;
  padding: 12px 16px;
}
.l6-layout-4 .l6-unit-examples span {
  padding: 6px 10px;
  font-size: 17px;
}
.l6-layout-4 .l6-usage-foundation .l6-amount-formula > span:first-child {
  width: 100%;
  text-align: center;
}
.l6-layout-4 .l6-usage-foundation .l6-amount-formula small {
  font-size: 16px;
  line-height: 1.4;
}
@media (max-width: 1150px) {
  .l6-layout-3 .l6-supply-diagram {
    grid-template-columns: 100px 70px 100px 55px minmax(0, 1fr);
  }
  .l6-layout-3 .l6-energy-thumbs span {
    white-space: normal;
  }
  .l6-usage-foundation {
    grid-template-columns: 1fr;
  }
  .l6-layout-4 .l6-usage-foundation .l6-amount-formula > span:first-child {
    width: auto;
  }
}
@media (max-width: 800px) {
  .l6-layout-3 .l6-supply-diagram {
    grid-template-columns: 100px 65px 100px;
  }
  .l6-layout-3 .l6-energy-thumbs {
    grid-column: 2/4;
  }
  .l6-layout-3 .l6-supply-node {
    flex-direction: column;
  }
  .l6-layout-3 .l6-supply-diagram figcaption {
    font-size: 14px;
  }
  .l6-power-caption {
    flex-direction: column;
    align-items: flex-start;
  }
  .l6-power-caption p {
    flex: auto;
  }
  .l6-layout-4 .l6-usage-foundation .l6-amount-formula {
    font-size: 22px;
  }
}

@media (min-width: 1151px) {
  .l6-layout-3 .l6-supply-diagram {
    grid-template-columns: 110px 75px 130px 60px minmax(0, 1fr);
  }
  .l6-layout-3 .l6-supply-node strong {
    white-space: nowrap;
  }
}

/* The heading sits above the reason box, without pushing the card pair down. */
.lesson6-flow .l6-round-list li {
  padding-top: 40px;
}
.lesson6-flow .l6-round-list li > .l6-round-row {
  display: inline-grid;
  width: 100%;
  padding: 0;
  grid-template-columns: minmax(0, 1.2fr) minmax(0, 1fr);
  grid-template-areas: "cards answer" "choice .";
  position: relative;
  column-gap: 20px;
  row-gap: 8px;
  vertical-align: top;
}
.l6-round-row .l6-round-reason-title {
  grid-area: answer;
  position: absolute;
  left: 0;
  right: 0;
  bottom: calc(100% + 8px);
  display: block;
  font-size: 19px;
  font-weight: 650;
  line-height: 1.45;
}
.l6-round-row .l6-mini-duel {
  grid-area: cards;
}
.l6-round-row .l6-saved-choice {
  grid-area: choice;
  margin: 0;
}
.lesson6-flow .l6-round-row textarea {
  grid-area: answer;
  align-self: stretch;
  height: 100%;
  min-height: 96px;
  margin: 0;
  padding: 10px 14px;
}
@media (max-width: 1150px) {
  .lesson6-flow .l6-round-list li > .l6-round-row {
    grid-template-columns: 1fr;
    grid-template-areas: "cards" "choice" "heading" "answer";
    row-gap: 10px;
  }
  .l6-round-row .l6-round-reason-title {
    grid-area: heading;
    position: static;
  }
  .lesson6-flow .l6-round-row textarea {
    height: 110px;
  }
}