:root {
  color-scheme: light;
  --ink: #1b2421;
  --muted: #5c6761;
  --line: #d9ded4;
  --paper: #f7f5ef;
  --panel: #fffdf7;
  --teal: #0f766e;
  --red: #e54a3b;
  --gold: #f0b936;
  --green: #2f8f62;
  font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  background: var(--paper);
  color: var(--ink);
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  background:
    linear-gradient(90deg, rgba(15, 118, 110, 0.07) 1px, transparent 1px),
    linear-gradient(rgba(15, 118, 110, 0.06) 1px, transparent 1px),
    var(--paper);
  background-size: 52px 52px;
}

a {
  color: var(--teal);
  font-weight: 800;
}

header {
  position: sticky;
  top: 0;
  z-index: 10;
  border-bottom: 1px solid rgba(27, 36, 33, 0.12);
  background: rgba(247, 245, 239, 0.94);
  backdrop-filter: blur(14px);
}

nav,
.wrap {
  width: min(1120px, calc(100% - 40px));
  margin: 0 auto;
}

nav {
  min-height: 66px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
}

.brand {
  color: var(--ink);
  text-decoration: none;
  display: flex;
  align-items: center;
  gap: 12px;
  font-weight: 900;
}

.dots {
  width: 48px;
  height: 14px;
  position: relative;
}

.dots::before,
.dots::after,
.dots span {
  content: "";
  position: absolute;
  top: 1px;
  width: 12px;
  height: 12px;
  border-radius: 999px;
}

.dots::before {
  left: 0;
  background: var(--red);
}

.dots span {
  left: 18px;
  background: var(--gold);
}

.dots::after {
  left: 36px;
  background: var(--teal);
}

.navlinks {
  display: flex;
  gap: 18px;
  flex-wrap: wrap;
  justify-content: flex-end;
  font-size: 14px;
}

.navlinks a {
  color: var(--ink);
  text-decoration: none;
}

main {
  padding: 54px 0 72px;
}

.eyebrow {
  display: inline-flex;
  align-items: center;
  margin: 0 0 16px;
  color: var(--teal);
  font-size: 13px;
  font-weight: 900;
  text-transform: uppercase;
}

h1,
h2,
h3,
p {
  margin-top: 0;
}

h1 {
  max-width: 900px;
  margin-bottom: 18px;
  font-size: clamp(40px, 7vw, 76px);
  line-height: 1;
  letter-spacing: 0;
}

h2 {
  margin: 44px 0 18px;
  font-size: clamp(26px, 4vw, 40px);
  letter-spacing: 0;
}

h3 {
  margin-bottom: 10px;
}

.lead {
  max-width: 760px;
  color: var(--muted);
  font-size: 20px;
  line-height: 1.7;
}

.actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin: 26px 0 0;
}

.button {
  display: inline-flex;
  align-items: center;
  min-height: 44px;
  padding: 0 16px;
  border: 1px solid var(--ink);
  border-radius: 6px;
  background: var(--ink);
  color: #fff;
  text-decoration: none;
  font-weight: 900;
}

.button.secondary {
  background: transparent;
  color: var(--ink);
}

.button.ghost {
  border-color: transparent;
  background: transparent;
  color: var(--teal);
  padding-inline: 0;
}

.grid {
  display: grid;
  gap: 14px;
}

.learning-path {
  grid-template-columns: repeat(4, minmax(0, 1fr));
}

.lesson-grid {
  grid-template-columns: repeat(3, minmax(0, 1fr));
}

.ai-track-grid {
  grid-template-columns: repeat(3, minmax(0, 1fr));
}

.tool-grid {
  grid-template-columns: repeat(4, minmax(0, 1fr));
}

.two-col {
  grid-template-columns: minmax(0, 0.72fr) minmax(280px, 0.28fr);
  align-items: start;
}

.card,
.panel {
  padding: 20px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: rgba(255, 253, 247, 0.88);
}

.card p,
.panel p,
.panel li {
  color: var(--muted);
  line-height: 1.65;
}

.teacher-card {
  display: grid;
  grid-template-columns: 168px minmax(0, 1fr);
  gap: 24px;
  align-items: center;
  padding: 24px;
  border: 1px solid rgba(15, 118, 110, 0.22);
  border-radius: 8px;
  background: rgba(255, 253, 247, 0.94);
}

.teacher-card.featured {
  grid-template-columns: minmax(280px, 0.48fr) minmax(0, 0.52fr);
  padding: 28px;
  background:
    linear-gradient(135deg, rgba(255, 253, 247, 0.98), rgba(255, 253, 247, 0.9)),
    rgba(15, 118, 110, 0.08);
}

.teacher-card.compact {
  grid-template-columns: 104px minmax(0, 1fr);
  padding: 16px;
}

.teacher-card img,
.teacher-avatar {
  display: block;
  width: 100%;
  max-width: 168px;
  aspect-ratio: 1 / 1;
  object-fit: contain;
  mix-blend-mode: multiply;
}

.ai-hero {
  display: grid;
  grid-template-columns: minmax(0, 0.95fr) minmax(360px, 1.05fr);
  gap: 36px;
  align-items: center;
}

.ai-hero-figure {
  margin: 0;
  padding: 20px;
  border: 1px solid rgba(27, 36, 33, 0.14);
  border-radius: 8px;
  background: rgba(255, 253, 247, 0.9);
}

.ai-hero-figure img {
  display: block;
  width: 100%;
  aspect-ratio: 16 / 10;
  object-fit: contain;
  mix-blend-mode: multiply;
}

.ai-track-card {
  display: flex;
  flex-direction: column;
  min-height: 100%;
}

.ai-track-card img {
  display: block;
  width: 100%;
  margin-bottom: 16px;
  aspect-ratio: 16 / 10;
  object-fit: contain;
  border: 1px solid rgba(27, 36, 33, 0.1);
  border-radius: 8px;
  background: #fff;
  mix-blend-mode: multiply;
}

.compact-timeline {
  margin-bottom: 0;
}

.ai-link-list {
  display: grid;
  gap: 16px;
  padding-left: 0;
  list-style: none;
}

.ai-link-list li {
  padding-top: 14px;
  border-top: 1px solid var(--line);
}

.ai-link-list a,
.ai-link-list span {
  display: block;
}

.ai-link-list span {
  margin-top: 5px;
  color: var(--muted);
  line-height: 1.55;
}

.teacher-card.featured img {
  max-width: 100%;
}

.teacher-card.featured .cange-scene {
  width: 100%;
  max-height: 300px;
  aspect-ratio: 16 / 10;
  object-fit: contain;
  border: 1px solid rgba(27, 36, 33, 0.12);
  border-radius: 8px;
  background: #fff;
  mix-blend-mode: normal;
}

.teacher-card.compact img {
  max-width: 104px;
}

.teacher-card h3,
.teacher-card p {
  margin-bottom: 8px;
}

.teacher-card p:last-child {
  margin-bottom: 0;
}

.teacher-name {
  color: var(--teal);
  font-weight: 950;
}

.teacher-prop {
  margin-top: 14px;
  padding: 14px 16px;
  border: 1px dashed rgba(27, 36, 33, 0.22);
  border-radius: 8px;
  background: rgba(240, 185, 54, 0.12);
}

.teacher-prop strong {
  display: block;
  margin-bottom: 5px;
}

.teacher-prop span {
  color: var(--muted);
  line-height: 1.6;
}

.prop-note {
  display: grid;
  grid-template-columns: 120px minmax(0, 1fr);
  gap: 16px;
  align-items: start;
  padding: 18px 20px;
  border: 1px solid rgba(240, 185, 54, 0.36);
  border-radius: 8px;
  background: rgba(240, 185, 54, 0.12);
}

.prop-object {
  display: grid;
  place-items: center;
  min-height: 86px;
  padding: 14px;
  border: 2px solid rgba(27, 36, 33, 0.72);
  border-radius: 8px;
  background: #fffdf7;
  color: var(--ink);
  font-weight: 950;
  text-align: center;
}

.prop-note p {
  margin-bottom: 0;
}

.classroom-board {
  display: grid;
  gap: 16px;
  margin: 22px 0;
  padding: 20px;
  border: 2px solid rgba(27, 36, 33, 0.72);
  border-radius: 8px;
  background: #fffdf7;
  box-shadow: 8px 8px 0 rgba(15, 118, 110, 0.1);
}

.classroom-board h2 {
  margin: 0;
}

.classroom-grid {
  display: grid;
  grid-template-columns: 1.15fr 0.85fr;
  gap: 14px;
}

.keyword-strip {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin: 8px 0 0;
}

.keyword {
  display: inline-flex;
  align-items: center;
  min-height: 30px;
  padding: 0 10px;
  border: 1px dashed rgba(27, 36, 33, 0.35);
  border-radius: 999px;
  background: rgba(255, 255, 255, 0.78);
  color: var(--ink);
  font-size: 14px;
  font-weight: 900;
}

.keyword.red {
  color: var(--red);
}

.keyword.gold {
  color: #b57a00;
}

.keyword.blue {
  color: #2f61b7;
}

.classroom-object {
  padding: 16px;
  border: 1px solid rgba(240, 185, 54, 0.46);
  border-radius: 8px;
  background: rgba(240, 185, 54, 0.13);
}

.classroom-object strong,
.classroom-action strong {
  display: block;
  margin-bottom: 6px;
  color: var(--ink);
}

.classroom-action {
  padding: 16px;
  border: 1px solid rgba(15, 118, 110, 0.28);
  border-radius: 8px;
  background: rgba(15, 118, 110, 0.08);
}

.classroom-board p {
  margin-bottom: 0;
  color: var(--muted);
  line-height: 1.65;
}

.copy-lab {
  overflow: hidden;
  margin: 18px 0 28px;
  border: 1px solid rgba(27, 36, 33, 0.18);
  border-radius: 8px;
  background: #fffdf7;
}

.copy-lab-head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  padding: 14px 16px;
  border-bottom: 1px solid var(--line);
  background: rgba(15, 118, 110, 0.08);
}

.copy-button {
  min-height: 36px;
  padding-inline: 12px;
  font-size: 13px;
}

.copy-lab textarea {
  width: 100%;
  min-height: 360px;
  padding: 18px;
  border: 0;
  border-radius: 0;
  background: rgba(255, 255, 255, 0.72);
  color: var(--ink);
  font: 15px/1.65 ui-monospace, SFMono-Regular, Menlo, Consolas, "Liberation Mono", monospace;
  resize: vertical;
}

.copy-lab textarea:focus {
  outline: 2px solid rgba(15, 118, 110, 0.35);
  outline-offset: -2px;
}

.step-cards {
  grid-template-columns: repeat(3, minmax(0, 1fr));
}

.step-card {
  position: relative;
  min-height: 100%;
}

.step-badge {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-width: 34px;
  height: 34px;
  margin-bottom: 14px;
  border-radius: 999px;
  background: var(--ink);
  color: #fff;
  font-weight: 950;
}

.diagram {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 10px;
  margin: 20px 0;
}

.diagram-node {
  min-height: 92px;
  padding: 14px;
  border: 1px dashed rgba(15, 118, 110, 0.45);
  border-radius: 8px;
  background: rgba(15, 118, 110, 0.07);
}

.diagram-node strong {
  display: block;
  margin-bottom: 6px;
}

.diagram-node span {
  color: var(--muted);
  font-size: 14px;
  line-height: 1.45;
}

.meta {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin: 14px 0;
}

.pill {
  display: inline-flex;
  align-items: center;
  min-height: 28px;
  padding: 0 10px;
  border-radius: 999px;
  background: rgba(15, 118, 110, 0.12);
  color: var(--teal);
  font-size: 13px;
  font-weight: 900;
}

.pill.locked {
  background: rgba(229, 74, 59, 0.12);
  color: var(--red);
}

.pill.free {
  background: rgba(47, 143, 98, 0.14);
  color: var(--green);
}

.score {
  display: grid;
  gap: 8px;
  align-content: center;
  min-height: 150px;
  text-align: center;
}

.score strong {
  font-size: clamp(48px, 8vw, 76px);
  line-height: 1;
}

.score.low strong,
.status-low {
  color: var(--green);
}

.score.medium strong,
.status-medium {
  color: var(--gold);
}

.score.high strong,
.status-high {
  color: var(--red);
}

.check-row {
  display: grid;
  grid-template-columns: 24px minmax(0, 1fr);
  gap: 10px;
  align-items: start;
  padding: 12px 0;
  border-top: 1px solid var(--line);
}

.check-row input {
  width: 18px;
  min-height: 18px;
  margin-top: 4px;
}

.check-row strong {
  display: block;
  margin-bottom: 4px;
}

.check-row span {
  color: var(--muted);
  line-height: 1.55;
}

.meter {
  overflow: hidden;
  height: 12px;
  border-radius: 999px;
  background: rgba(27, 36, 33, 0.1);
}

.meter span {
  display: block;
  width: 0;
  height: 100%;
  border-radius: inherit;
  background: var(--green);
  transition: width 180ms ease, background 180ms ease;
}

.kv {
  display: grid;
  gap: 9px;
}

.kv div {
  display: grid;
  grid-template-columns: 150px minmax(0, 1fr);
  gap: 12px;
  padding: 10px 0;
  border-top: 1px solid var(--line);
}

.kv dt {
  color: var(--muted);
  font-weight: 800;
}

.kv dd {
  margin: 0;
  overflow-wrap: anywhere;
  color: #34413b;
}

.lesson-card {
  display: flex;
  flex-direction: column;
  min-height: 100%;
}

.lesson-card .button {
  margin-top: auto;
  align-self: flex-start;
}

.lesson-no {
  color: var(--teal);
  font-size: 13px;
  font-weight: 900;
}

.module-title {
  padding: 12px 0;
  border-top: 1px solid var(--line);
  color: var(--teal);
  font-size: 14px;
  font-weight: 900;
  text-transform: uppercase;
}

.lesson-body {
  font-size: 18px;
  line-height: 1.78;
}

.lesson-body p,
.lesson-body li {
  color: #34413b;
}

.lesson-body h2 {
  margin-top: 38px;
  font-size: clamp(24px, 3vw, 34px);
}

.lesson-body h3 {
  margin-top: 28px;
}

.lesson-body blockquote {
  margin: 24px 0;
  padding: 18px 22px;
  border-left: 5px solid var(--teal);
  background: rgba(15, 118, 110, 0.08);
}

.lesson-body .callout {
  padding: 18px 20px;
  border: 1px solid rgba(15, 118, 110, 0.22);
  border-radius: 8px;
  background: rgba(15, 118, 110, 0.08);
}

.checklist li {
  margin-bottom: 8px;
}

code,
pre {
  border-radius: 6px;
  background: rgba(27, 36, 33, 0.08);
}

code {
  padding: 2px 6px;
  font-size: 0.92em;
}

pre {
  overflow: auto;
  padding: 16px;
}

pre code {
  padding: 0;
  background: transparent;
}

.lock-box {
  border: 1px solid rgba(229, 74, 59, 0.35);
  background: rgba(229, 74, 59, 0.07);
}

.lesson-nav {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  justify-content: space-between;
  margin-top: 34px;
  padding-top: 22px;
  border-top: 1px solid var(--line);
}

.side-list {
  margin: 0;
  padding-left: 19px;
}

.side-list li {
  margin-bottom: 10px;
}

form {
  display: grid;
  gap: 14px;
  max-width: 460px;
}

label {
  display: grid;
  gap: 7px;
  color: var(--ink);
  font-weight: 800;
}

input {
  width: 100%;
  min-height: 44px;
  padding: 0 12px;
  border: 1px solid var(--line);
  border-radius: 6px;
  background: #fff;
  color: var(--ink);
  font: inherit;
}

.notice {
  margin-top: 14px;
  color: var(--muted);
  font-size: 14px;
  line-height: 1.6;
}

.form-status {
  min-height: 22px;
  color: var(--muted);
  font-weight: 800;
}

.form-status.error {
  color: var(--red);
}

.form-status.ok {
  color: var(--green);
}

footer {
  padding: 34px 0 46px;
  border-top: 1px solid var(--line);
  color: var(--muted);
}

@media (max-width: 900px) {
  .lesson-grid,
  .ai-track-grid,
  .tool-grid,
  .learning-path,
  .step-cards,
  .diagram,
  .ai-hero,
  .two-col {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 640px) {
  nav,
  .wrap {
    width: min(100% - 28px, 1120px);
  }

  nav {
    align-items: flex-start;
    flex-direction: column;
    padding: 16px 0;
  }

  .navlinks {
    justify-content: flex-start;
  }

  .teacher-card,
  .teacher-card.compact {
    grid-template-columns: 94px minmax(0, 1fr);
    gap: 14px;
    padding: 16px;
  }

  .teacher-card.featured {
    grid-template-columns: 1fr;
  }

  .teacher-card img,
  .teacher-card.compact img {
    max-width: 116px;
  }

  .teacher-card.featured img,
  .teacher-card.featured .cange-scene {
    max-width: 100%;
  }

  .prop-note {
    grid-template-columns: 1fr;
  }

  .classroom-grid {
    grid-template-columns: 1fr;
  }

  .copy-lab-head {
    align-items: flex-start;
    flex-direction: column;
  }
}