:root {
  --page: #f5f7f6;
  --surface: #ffffff;
  --surface-soft: #f9faf9;
  --ink: #20262a;
  --muted: #68747a;
  --line: #dfe5e2;
  --line-strong: #c6d0cc;
  --green: #0f766e;
  --green-dark: #0b5f58;
  --brick: #9d5146;
  --gold: #b9832f;
  --slate: #344054;
  --shadow: 0 18px 45px rgba(32, 38, 42, 0.08);
  --radius: 10px;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  min-width: 320px;
  color: var(--ink);
  background: var(--page);
  font-family:
    Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI",
    sans-serif;
}

button,
input,
textarea {
  font: inherit;
}

button {
  color: inherit;
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 20;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 28px;
  padding: 18px max(24px, calc((100vw - 1180px) / 2));
  border-bottom: 1px solid var(--line);
  background: rgba(255, 255, 255, 0.94);
  backdrop-filter: blur(14px);
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  min-width: 280px;
  color: inherit;
  text-decoration: none;
}

.brand-mark {
  display: grid;
  width: 44px;
  height: 44px;
  place-items: center;
  border-radius: 8px;
  background: var(--green-dark);
  color: #fff;
  font-weight: 800;
}

.brand strong,
.brand small {
  display: block;
}

.brand strong {
  line-height: 1.15;
  letter-spacing: 0;
}

.brand small {
  margin-top: 4px;
  color: var(--muted);
  font-size: 0.84rem;
}

.top-nav {
  display: grid;
  grid-template-columns: repeat(4, minmax(92px, 1fr));
  gap: 4px;
  min-width: min(520px, 100%);
  padding: 4px;
  border: 1px solid var(--line);
  border-radius: 999px;
  background: var(--surface-soft);
}

.nav-button,
.primary-action,
.secondary-action,
.chip,
.card,
.comment-form button {
  cursor: pointer;
}

.nav-button {
  min-height: 38px;
  padding: 0 14px;
  border: 0;
  border-radius: 999px;
  background: transparent;
  color: var(--muted);
  font-size: 0.93rem;
  font-weight: 700;
}

.nav-button:hover,
.nav-button:focus-visible,
.nav-button.is-active {
  background: var(--green-dark);
  color: #fff;
  outline: 0;
}

.workspace {
  width: min(1180px, calc(100% - 36px));
  margin: 28px auto 52px;
}

.stage {
  min-width: 0;
}

.page-head {
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto;
  gap: 24px;
  align-items: end;
  margin-bottom: 18px;
  padding: 28px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--surface);
  box-shadow: var(--shadow);
}

.page-head h1 {
  max-width: 820px;
  margin: 0;
  font-size: clamp(1.75rem, 3vw, 3rem);
  line-height: 1.04;
  letter-spacing: 0;
}

.page-head p {
  max-width: 780px;
  margin: 12px 0 0;
  color: var(--muted);
  line-height: 1.6;
}

.eyebrow {
  margin: 0 0 8px;
  color: var(--brick);
  font-size: 0.74rem;
  font-weight: 800;
  letter-spacing: 0;
  text-transform: uppercase;
}

.head-actions,
.button-row {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

.head-actions {
  justify-content: flex-end;
}

.primary-action,
.secondary-action {
  min-height: 42px;
  padding: 0 16px;
  border-radius: 8px;
  font-weight: 800;
}

.primary-action {
  border: 1px solid var(--green-dark);
  background: var(--green-dark);
  color: #fff;
}

.secondary-action {
  border: 1px solid var(--line-strong);
  background: var(--surface);
  color: var(--slate);
}

.primary-action:hover,
.primary-action:focus-visible,
.secondary-action:hover,
.secondary-action:focus-visible {
  border-color: var(--green);
  outline: 3px solid rgba(15, 118, 110, 0.13);
}

.grid {
  display: grid;
  gap: 16px;
}

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

.two-col {
  grid-template-columns: repeat(2, minmax(0, 1fr));
}

.video-grid,
.question-grid,
.text-grid,
.practice-grid,
.text-bank {
  grid-template-columns: repeat(4, minmax(0, 1fr));
}

.model3-grid {
  grid-template-columns: minmax(0, 0.9fr) minmax(0, 1.1fr);
}

.book-text-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 14px;
}

.card,
.work-panel,
.reading-panel,
.note-panel {
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--surface);
}

.card {
  display: flex;
  min-height: 180px;
  flex-direction: column;
  justify-content: space-between;
  padding: 18px;
  text-align: left;
  transition:
    border-color 160ms ease,
    box-shadow 160ms ease,
    transform 160ms ease;
}

button.card {
  width: 100%;
  border: 1px solid var(--line);
}

.card:hover,
.card:focus-visible,
.card.is-selected {
  border-color: var(--green);
  box-shadow: 0 14px 34px rgba(15, 118, 110, 0.1);
  outline: 0;
  transform: translateY(-1px);
}

.card h2,
.card h3 {
  margin: 0;
  line-height: 1.18;
  letter-spacing: 0;
}

.card h2 {
  font-size: 1.18rem;
}

.card h3 {
  font-size: 1.03rem;
}

.card p {
  margin: 10px 0 0;
  color: var(--muted);
  line-height: 1.55;
}

.card-meta {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 10px;
  margin-top: 18px;
  color: var(--muted);
  font-size: 0.86rem;
  font-weight: 800;
}

.tab-index {
  display: grid;
  width: 42px;
  height: 42px;
  place-items: center;
  margin-bottom: 16px;
  border-radius: 8px;
  background: #e8f2ef;
  color: var(--green-dark);
  font-weight: 900;
}

.module-card {
  min-height: 260px;
}

.video-card {
  min-height: 242px;
}

.question-card,
.text-card,
.practice-card {
  min-height: 250px;
}

.mini-text {
  min-height: 210px;
}

.book-text-card {
  min-height: 245px;
}

.text-meta-list {
  display: flex;
  flex-wrap: wrap;
  gap: 7px;
  margin-top: 14px;
}

.text-meta-list span {
  display: inline-flex;
  min-height: 28px;
  align-items: center;
  padding: 0 9px;
  border: 1px solid var(--line);
  border-radius: 999px;
  background: var(--surface-soft);
  color: var(--slate);
  font-size: 0.78rem;
  font-weight: 800;
}

.work-panel,
.reading-panel,
.note-panel {
  padding: 22px;
}

.work-panel h2,
.reading-panel h2,
.note-panel h2 {
  margin: 0;
  letter-spacing: 0;
}

.work-panel p,
.reading-panel p,
.note-panel p {
  color: var(--muted);
  line-height: 1.65;
}

.video-frame {
  display: grid;
  min-height: 118px;
  margin-bottom: 15px;
  place-items: center;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: #eef3f1;
  color: var(--green-dark);
  font-weight: 900;
}

.video-embed {
  position: relative;
  overflow: hidden;
  width: 100%;
  aspect-ratio: 16 / 9;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: #eef3f1;
}

.video-embed iframe {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  border: 0;
}

.video-placeholder {
  display: grid;
  min-height: 260px;
  place-items: center;
  padding: 22px;
  text-align: center;
}

.video-placeholder strong {
  display: block;
  color: var(--green-dark);
  font-size: 1.05rem;
}

.video-placeholder span {
  display: block;
  max-width: 420px;
  margin-top: 8px;
  color: var(--muted);
  line-height: 1.5;
}

.video-thumb {
  position: relative;
  display: grid;
  min-height: 104px;
  margin-bottom: 14px;
  overflow: hidden;
  place-items: center;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: #e8f2ef;
  color: var(--green-dark);
  font-weight: 900;
}

.video-thumb img {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.video-thumb::after {
  content: "";
  position: absolute;
  inset: 0;
  background: linear-gradient(180deg, rgba(15, 38, 35, 0.05), rgba(15, 38, 35, 0.42));
}

.video-thumb span {
  position: relative;
  z-index: 1;
  display: inline-flex;
  min-height: 30px;
  align-items: center;
  padding: 0 12px;
  border-radius: 999px;
  background: rgba(255, 255, 255, 0.92);
  color: var(--green-dark);
  font-size: 0.82rem;
}

.video-thumb-placeholder::after {
  display: none;
}

.practice-video-layout {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(280px, 0.46fr);
  gap: 18px;
  margin-top: 16px;
  align-items: stretch;
}

.method-note {
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--surface-soft);
  padding: 18px;
}

.method-note h3 {
  margin: 0;
  font-size: 1.18rem;
}

.method-note p:not(.eyebrow) {
  margin: 10px 0 0;
  color: var(--muted);
  line-height: 1.6;
}

.activity-layout {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(300px, 0.68fr);
  gap: 18px;
  margin-top: 16px;
  align-items: start;
}

.sample-text {
  padding: 18px;
  border: 1px solid var(--line);
  border-left: 4px solid var(--green);
  border-radius: 8px;
  background: var(--surface-soft);
  line-height: 1.75;
}

.reader-screen {
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--surface);
  padding: 18px;
  box-shadow: var(--shadow);
}

.reader-layout {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(320px, 0.42fr);
  gap: 18px;
  align-items: start;
}

.book-text-panel,
.question-dock {
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--surface-soft);
  padding: 22px;
}

.book-text-panel {
  min-height: 640px;
}

.book-text-panel h2,
.question-dock h2 {
  margin: 0 0 14px;
}

.book-text-panel p:not(.eyebrow) {
  margin: 0 0 16px;
  color: var(--ink);
  font-size: 1.02rem;
  line-height: 1.85;
}

.question-dock {
  position: sticky;
  top: 96px;
  display: grid;
  gap: 12px;
}

.question-group {
  border: 1px solid var(--line);
  border-radius: 8px;
  background: #fff;
  padding: 14px;
}

.question-group h3 {
  margin: 0;
  color: var(--green-dark);
  font-size: 1rem;
}

.question-group p {
  margin: 6px 0 10px;
  color: var(--muted);
  font-size: 0.9rem;
  font-weight: 750;
}

.question-group ul {
  display: grid;
  gap: 8px;
  margin: 0;
  padding-left: 18px;
}

.question-group li {
  color: var(--ink);
  line-height: 1.45;
}

.prompt-list {
  display: grid;
  gap: 10px;
  margin: 14px 0 0;
  padding: 0;
  list-style: none;
}

.prompt-list li {
  padding: 13px 14px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--surface-soft);
  line-height: 1.5;
}

.response-box {
  display: grid;
  gap: 11px;
  margin-top: 15px;
}

.response-box label {
  color: var(--slate);
  font-weight: 800;
}

.response-box textarea {
  width: 100%;
  min-height: 150px;
  resize: vertical;
  padding: 13px;
  border: 1px solid var(--line-strong);
  border-radius: 8px;
  background: #fff;
  color: var(--ink);
  line-height: 1.55;
}

.response-box textarea:focus {
  border-color: var(--green);
  outline: 3px solid rgba(15, 118, 110, 0.13);
}

.quadrant {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 12px;
  margin-top: 16px;
}

.quadrant-item {
  min-height: 128px;
  padding: 15px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--surface-soft);
  line-height: 1.55;
}

.quadrant-item strong {
  display: block;
  margin-bottom: 8px;
  color: var(--slate);
}

.empty-state {
  display: grid;
  min-height: 260px;
  place-items: center;
  border: 1px dashed var(--line-strong);
  border-radius: var(--radius);
  background: var(--surface-soft);
  color: var(--muted);
  text-align: center;
}

.comment-form {
  display: grid;
  gap: 14px;
  margin-top: 20px;
  padding: 18px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--surface-soft);
}

.comment-form h3 {
  margin: 0;
  font-size: 1.08rem;
}

.comment-form p {
  margin: 0;
  color: var(--muted);
  line-height: 1.55;
}

.form-grid {
  display: grid;
  grid-template-columns: minmax(170px, 0.32fr) minmax(0, 1fr);
  gap: 12px;
}

.field {
  display: grid;
  gap: 7px;
}

.field label {
  color: var(--slate);
  font-size: 0.9rem;
  font-weight: 800;
}

.field input,
.field textarea {
  width: 100%;
  border: 1px solid var(--line-strong);
  border-radius: 8px;
  background: #fff;
  color: var(--ink);
}

.field input {
  min-height: 42px;
  padding: 0 12px;
}

.field textarea {
  min-height: 100px;
  resize: vertical;
  padding: 12px;
  line-height: 1.55;
}

.field input:focus,
.field textarea:focus {
  border-color: var(--green);
  outline: 3px solid rgba(15, 118, 110, 0.13);
}

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

@media (max-width: 1040px) {
  .site-header {
    align-items: stretch;
    flex-direction: column;
  }

  .brand {
    min-width: 0;
  }

  .top-nav {
    width: 100%;
  }

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

  .video-grid,
  .question-grid,
  .text-grid,
  .practice-grid,
  .text-bank,
  .book-text-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .page-head,
  .two-col,
  .model3-grid,
  .activity-layout,
  .reader-layout,
  .practice-video-layout {
    grid-template-columns: 1fr;
  }

  .question-dock {
    position: static;
  }

  .head-actions {
    justify-content: flex-start;
  }
}

@media (max-width: 640px) {
  .site-header {
    padding: 14px;
  }

  .workspace {
    width: min(100% - 24px, 620px);
    margin-top: 18px;
  }

  .top-nav,
  .video-grid,
  .question-grid,
  .text-grid,
  .practice-grid,
  .text-bank,
  .book-text-grid,
  .quadrant,
  .form-grid {
    grid-template-columns: 1fr;
  }

  .page-head,
  .work-panel,
  .reading-panel,
  .note-panel,
  .reader-screen,
  .book-text-panel,
  .question-dock {
    padding: 18px;
  }

  .module-card,
  .video-card,
  .question-card,
  .text-card,
  .practice-card,
  .mini-text,
  .book-text-card {
    min-height: auto;
  }

  .book-text-panel {
    min-height: auto;
  }
}