/* Theme tokens and global page defaults */
:root {
  color-scheme: light;
  --bg: #f6f8ff;
  --bg-strong: #ffffff;
  --panel: rgba(255, 255, 255, 0.92);
  --panel-strong: #ffffff;
  --text: #182033;
  --muted: #5f6f89;
  --border: #dce5f5;
  --primary: #2457e6;
  --primary-deep: #183fa8;
  --purple: #7b3ff2;
  --green: #12805c;
  --yellow: #ffcc66;
  --danger: #b13c4a;
  --shadow: 0 22px 60px rgba(37, 61, 120, 0.14);
  --shadow-soft: 0 12px 30px rgba(37, 61, 120, 0.1);
  --radius-xl: 28px;
  --radius-lg: 20px;
  --radius-md: 14px;
}

:root[data-theme="dark"] {
  color-scheme: dark;
  --bg: #101524;
  --bg-strong: #151c31;
  --panel: rgba(22, 30, 52, 0.92);
  --panel-strong: #1b2540;
  --text: #f2f6ff;
  --muted: #b4c1d8;
  --border: #32415f;
  --primary: #8fb1ff;
  --primary-deep: #c3d5ff;
  --purple: #c6a8ff;
  --green: #82deb8;
  --yellow: #ffd985;
  --danger: #ff9aac;
  --shadow: 0 22px 60px rgba(0, 0, 0, 0.35);
  --shadow-soft: 0 12px 30px rgba(0, 0, 0, 0.24);
}

* {
  box-sizing: border-box;
}

[hidden] {
  display: none !important;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  color: var(--text);
  font-family:
    Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI",
    sans-serif;
  background:
    radial-gradient(circle at 12% 10%, rgba(123, 63, 242, 0.16), transparent 26%),
    radial-gradient(circle at 82% 8%, rgba(18, 128, 92, 0.16), transparent 24%),
    linear-gradient(180deg, var(--bg), #eef4ff 48%, var(--bg));
  min-height: 100vh;
}

:root[data-theme="dark"] body {
  background:
    radial-gradient(circle at 12% 10%, rgba(143, 177, 255, 0.16), transparent 26%),
    radial-gradient(circle at 82% 8%, rgba(130, 222, 184, 0.1), transparent 24%),
    linear-gradient(180deg, var(--bg), #111a2d 48%, var(--bg));
}

button,
input {
  font: inherit;
}

a {
  color: inherit;
}

code,
pre {
  font-family: "SFMono-Regular", Consolas, "Liberation Mono", monospace;
}

.skip-link {
  position: fixed;
  left: 1rem;
  top: 1rem;
  z-index: 1000;
  transform: translateY(-160%);
  padding: 0.75rem 1rem;
  border-radius: 999px;
  color: white;
  background: var(--primary-deep);
  text-decoration: none;
}

.skip-link:focus {
  transform: translateY(0);
}

.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

/* Sticky navigation and progress UI */
.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  padding: 0.75rem clamp(0.85rem, 3vw, 2rem);
  background: rgba(246, 248, 255, 0.86);
  border-bottom: 1px solid var(--border);
  backdrop-filter: blur(18px);
}

:root[data-theme="dark"] .site-header {
  background: rgba(16, 21, 36, 0.86);
}

.top-nav,
.progress-strip,
.category-nav,
main {
  width: min(1180px, 100%);
  margin: 0 auto;
}

.top-nav {
  display: flex;
  align-items: center;
  gap: 1rem;
  justify-content: space-between;
}

.brand,
.nav-link {
  text-decoration: none;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 0.65rem;
  font-weight: 850;
}

.brand-mark {
  display: grid;
  place-items: center;
  width: 2.4rem;
  height: 2.4rem;
  border-radius: 0.9rem;
  color: white;
  background: linear-gradient(135deg, var(--primary), var(--purple));
  box-shadow: var(--shadow-soft);
}

.nav-actions {
  display: flex;
  align-items: center;
  gap: 0.45rem;
}

.nav-link,
.theme-toggle,
.icon-button {
  border: 1px solid transparent;
  border-radius: 999px;
  padding: 0.72rem 0.9rem;
  color: var(--muted);
  background: transparent;
  font-weight: 750;
  cursor: pointer;
}

.nav-link:hover,
.theme-toggle:hover,
.icon-button:hover {
  color: var(--primary-deep);
  background: rgba(36, 87, 230, 0.08);
}

.theme-toggle {
  display: inline-flex;
  gap: 0.45rem;
  align-items: center;
}

.menu-button {
  display: none;
}

.progress-strip {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(180px, 360px);
  gap: 1rem;
  align-items: center;
  margin-top: 0.85rem;
  color: var(--muted);
  font-size: 0.92rem;
}

.progress-strip strong {
  display: block;
  color: var(--text);
}

.progress-track {
  height: 0.7rem;
  overflow: hidden;
  border-radius: 999px;
  background: rgba(36, 87, 230, 0.12);
}

.progress-track span {
  display: block;
  width: 0%;
  height: 100%;
  border-radius: inherit;
  background: linear-gradient(90deg, var(--green), var(--primary), var(--purple));
  transition: width 220ms ease;
}

.category-nav {
  display: flex;
  gap: 0.45rem;
  overflow-x: auto;
  padding: 0.75rem 0 0.1rem;
  scrollbar-width: thin;
}

.category-nav a {
  flex: 0 0 auto;
  padding: 0.6rem 0.8rem;
  border: 1px solid var(--border);
  border-radius: 999px;
  color: var(--muted);
  background: var(--panel);
  font-size: 0.9rem;
  font-weight: 750;
  text-decoration: none;
}

.category-nav a[aria-current="page"] {
  color: white;
  border-color: transparent;
  background: linear-gradient(135deg, var(--primary), var(--purple));
}

.category-nav a.is-complete::before {
  content: "✓ ";
  color: var(--green);
}

.category-nav a[aria-current="page"].is-complete::before {
  color: white;
}

main {
  padding: 1.4rem clamp(0.85rem, 3vw, 2rem) 4rem;
}

/* Homepage hero and learning map */
.hero-section {
  display: grid;
  grid-template-columns: minmax(0, 1.08fr) minmax(280px, 0.82fr);
  gap: 1.25rem;
  align-items: stretch;
  min-height: min(680px, calc(100vh - 10rem));
  padding: clamp(1rem, 2vw, 1.35rem);
  border: 1px solid var(--border);
  border-radius: var(--radius-xl);
  background:
    linear-gradient(135deg, rgba(36, 87, 230, 0.1), transparent 40%),
    var(--panel);
  box-shadow: var(--shadow);
}

.hero-copy,
.hero-panel {
  display: flex;
  flex-direction: column;
  justify-content: center;
}

.eyebrow {
  margin: 0 0 0.75rem;
  color: var(--primary-deep);
  font-size: 0.78rem;
  font-weight: 850;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

h1,
h2,
h3,
p {
  overflow-wrap: anywhere;
}

h1,
h2,
h3 {
  margin: 0;
  line-height: 1.06;
}

h1 {
  max-width: 9ch;
  font-size: clamp(3.2rem, 10vw, 6.9rem);
  letter-spacing: 0;
}

h2 {
  font-size: clamp(2rem, 4vw, 3.4rem);
}

h3 {
  font-size: 1.35rem;
}

.hero-subtitle {
  margin: 1rem 0 0;
  color: var(--primary-deep);
  font-size: clamp(1.3rem, 2vw, 1.7rem);
  font-weight: 850;
}

.hero-text,
.section-heading p,
.info-card p,
.warning-card p,
.lesson-intro,
.reflection-card p,
.debug-card p {
  color: var(--muted);
  line-height: 1.65;
}

.hero-text {
  max-width: 48rem;
  font-size: 1.12rem;
}

.hero-actions,
.card-actions,
.debug-actions,
.filter-buttons,
.rubric-header {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
  align-items: center;
}

.button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 2.75rem;
  padding: 0.82rem 1.05rem;
  border: 0;
  border-radius: 999px;
  font-weight: 850;
  text-decoration: none;
  cursor: pointer;
  transition: transform 160ms ease, box-shadow 160ms ease, background-color 160ms ease;
}

.button:hover {
  transform: translateY(-1px);
}

.button-primary {
  color: white;
  background: linear-gradient(135deg, var(--primary), var(--purple));
  box-shadow: var(--shadow-soft);
}

.button-secondary {
  color: var(--primary-deep);
  background: rgba(36, 87, 230, 0.1);
}

.hero-panel {
  gap: 1rem;
}

.orbit-card,
.info-card,
.warning-card,
.lesson-card,
.prompt-card,
.comparison-card,
.challenge-card,
.debug-card,
.reflection-card,
.tool-card,
.term-card,
.rubric-card,
.template-card {
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  background: var(--panel-strong);
  box-shadow: var(--shadow-soft);
}

.orbit-card {
  padding: 1.35rem;
  background:
    radial-gradient(circle at top right, rgba(255, 204, 102, 0.3), transparent 32%),
    var(--panel-strong);
}

.orbit-icon {
  display: grid;
  place-items: center;
  width: 3rem;
  height: 3rem;
  margin-bottom: 1rem;
  border-radius: 1rem;
  color: white;
  background: linear-gradient(135deg, var(--green), var(--primary));
}

.hero-checklist,
.step-list,
.bullet-list,
.checklist-list {
  margin: 0;
  padding-left: 1.2rem;
  color: var(--muted);
  line-height: 1.7;
}

.hero-checklist {
  padding: 1.2rem 1.4rem;
  border-radius: var(--radius-lg);
  background: rgba(18, 128, 92, 0.1);
}

.content-section,
.two-column-section,
/* Lesson cards, prompt boxes, debugging activities, and quizzes */
.learning-sections {
  margin-top: 1.4rem;
}

.section-heading {
  margin-bottom: 1rem;
}

.section-heading p {
  max-width: 48rem;
}

.category-grid {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 1rem;
}

.category-card {
  min-height: 13rem;
  padding: 1rem;
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  background: var(--panel-strong);
  box-shadow: var(--shadow-soft);
  text-decoration: none;
  transition: transform 160ms ease, border-color 160ms ease;
}

.category-card:hover {
  transform: translateY(-4px);
  border-color: rgba(36, 87, 230, 0.42);
}

.category-card span {
  font-size: 2rem;
}

.category-card h3 {
  margin-top: 1rem;
}

.category-card p {
  margin: 0.65rem 0 0;
  color: var(--muted);
  line-height: 1.5;
}

.two-column-section,
.teacher-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1rem;
}

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

.info-card,
.warning-card {
  padding: 1.15rem;
}

.warning-card {
  border-color: rgba(177, 60, 74, 0.26);
  background:
    linear-gradient(135deg, rgba(255, 204, 102, 0.2), transparent 48%),
    var(--panel-strong);
}

.learning-sections {
  display: grid;
  gap: 1.4rem;
}

.lesson-page-intro {
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.lesson-card {
  scroll-margin-top: 12rem;
  padding: clamp(1rem, 2vw, 1.35rem);
}

.lesson-header {
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto;
  gap: 1rem;
  align-items: start;
  margin-bottom: 1rem;
}

.completion-control {
  display: inline-flex;
  gap: 0.5rem;
  align-items: center;
  padding: 0.65rem 0.75rem;
  border: 1px solid var(--border);
  border-radius: 999px;
  color: var(--muted);
  background: rgba(36, 87, 230, 0.06);
  font-weight: 750;
  white-space: nowrap;
}

.lesson-layout {
  display: grid;
  grid-template-columns: minmax(0, 1.1fr) minmax(280px, 0.9fr);
  gap: 1rem;
}

.lesson-pager {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  gap: 0.75rem;
  margin-top: 1rem;
}

.lesson-column {
  display: grid;
  gap: 1rem;
  min-width: 0;
}

.editable-section {
  padding: 1rem;
  border: 1px dashed var(--border);
  border-radius: var(--radius-xl);
  background: rgba(36, 87, 230, 0.04);
}

.vocab-list {
  display: grid;
  gap: 0.65rem;
  margin: 0;
}

.vocab-list div {
  padding: 0.85rem;
  border-radius: var(--radius-md);
  background: rgba(36, 87, 230, 0.07);
}

.vocab-list dt {
  color: var(--text);
  font-weight: 850;
}

.vocab-list dd {
  margin: 0.25rem 0 0;
  color: var(--muted);
  line-height: 1.5;
}

.project-level-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 0.75rem;
}

.project-level-grid article {
  padding: 0.85rem;
  border-radius: var(--radius-md);
  background: rgba(18, 128, 92, 0.09);
}

.project-level-grid p {
  margin: 0.45rem 0 0;
  color: var(--muted);
  line-height: 1.5;
}

.project-planning-grid .info-card {
  display: grid;
  gap: 0.75rem;
}

.project-example-box {
  margin-top: auto;
  padding: 0.85rem;
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  color: var(--muted);
  background: rgba(18, 128, 92, 0.09);
  line-height: 1.55;
}

.project-example-box strong {
  color: var(--text);
}

.project-planning-table td:first-child {
  color: var(--text);
  font-weight: 850;
}

.project-planning-lab {
  grid-template-columns: repeat(2, minmax(0, 1fr));
}

.project-planning-lab .prompt-coach-field textarea {
  min-height: 7rem;
}

.project-planning-lab .card-actions,
.project-planning-lab .prompt-coach-results,
.project-planning-lab > div:last-child {
  grid-column: 1 / -1;
}

.prompt-strategy-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1rem;
}

.prompt-strategy-grid .info-card {
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
}

.prompt-strategy-grid .prompt-box {
  margin-top: auto;
}

.prompt-example-panel {
  margin-top: 1rem;
  padding: 1rem;
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  background: var(--panel-strong);
  box-shadow: var(--shadow-soft);
}

.prompt-coach-card {
  display: grid;
  gap: 1rem;
  margin-top: 1rem;
  padding: 1rem;
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  background:
    linear-gradient(135deg, rgba(36, 87, 230, 0.08), transparent 46%),
    var(--panel-strong);
  box-shadow: var(--shadow-soft);
}

.prompt-coach-field {
  display: grid;
  gap: 0.5rem;
  color: var(--text);
  font-weight: 850;
}

.prompt-coach-field input,
.prompt-coach-field select,
.prompt-coach-field textarea {
  width: 100%;
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  padding: 1rem;
  color: var(--text);
  background: var(--panel-strong);
  line-height: 1.55;
}

.prompt-coach-field textarea {
  min-height: 12rem;
  resize: vertical;
}

.debug-prompt-builder .prompt-coach-field textarea {
  min-height: 6rem;
}

.debug-prompt-builder #debugCodeSample {
  min-height: 11rem;
  font-family: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, "Liberation Mono", monospace;
}

.prompt-coach-results {
  display: grid;
  gap: 0.8rem;
}

.prompt-score {
  display: inline-flex;
  width: fit-content;
  padding: 0.55rem 0.75rem;
  border-radius: 999px;
  font-weight: 850;
}

.prompt-score-high {
  color: var(--green);
  background: rgba(18, 128, 92, 0.12);
}

.prompt-score-mid {
  color: var(--primary-deep);
  background: rgba(36, 87, 230, 0.12);
}

.prompt-score-low {
  color: var(--danger);
  background: rgba(177, 60, 74, 0.1);
}

.prompt-review-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 0.85rem;
}

.prompt-review-grid article {
  padding: 0.9rem;
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  background: rgba(255, 255, 255, 0.58);
}

:root[data-theme="dark"] .prompt-review-grid article {
  background: rgba(255, 255, 255, 0.04);
}

.prompt-review-grid h4 {
  margin: 0 0 0.5rem;
}

.prompt-review-grid ul {
  margin: 0;
  padding-left: 1.1rem;
  color: var(--muted);
  line-height: 1.55;
}

.muted-note {
  margin: 0;
  color: var(--muted);
}

.design-thinking-lab {
  display: grid;
  gap: 1rem;
  padding: clamp(1rem, 2vw, 1.35rem);
  border: 1px solid var(--border);
  border-radius: var(--radius-xl);
  background:
    linear-gradient(135deg, rgba(18, 128, 92, 0.08), transparent 48%),
    var(--panel-strong);
  box-shadow: var(--shadow-soft);
}

.design-step-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 1rem;
}

.design-step-card {
  display: grid;
  gap: 0.75rem;
  padding: 1rem;
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  background: var(--panel);
}

.design-step-card .step-number {
  display: inline-grid;
  place-items: center;
  width: 2.3rem;
  height: 2.3rem;
  border-radius: 999px;
  color: white;
  background: linear-gradient(135deg, var(--primary), var(--green));
  font-weight: 900;
}

.design-step-card h3,
.design-step-card p {
  margin: 0;
}

.design-step-card p {
  color: var(--muted);
  line-height: 1.5;
}

.design-step-card label {
  display: grid;
  gap: 0.5rem;
  color: var(--text);
  font-weight: 850;
}

.design-step-card textarea {
  width: 100%;
  min-height: 9.5rem;
  resize: vertical;
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  padding: 0.85rem;
  color: var(--text);
  background: var(--panel-strong);
  line-height: 1.55;
}

.design-review-panel {
  display: grid;
  gap: 0.9rem;
}

.design-review-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 0.85rem;
}

.design-review-grid article {
  padding: 0.9rem;
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  background: rgba(36, 87, 230, 0.06);
}

.design-review-grid h4 {
  margin: 0 0 0.4rem;
}

.design-review-grid ul {
  margin: 0.4rem 0 0.8rem;
  padding-left: 1.1rem;
  color: var(--muted);
  line-height: 1.5;
}

.review-status {
  margin: 0 0 0.7rem;
  color: var(--muted);
  font-weight: 800;
}

.html-reference-section {
  display: grid;
  gap: 1rem;
  padding: clamp(1rem, 2vw, 1.35rem);
  border: 1px solid var(--border);
  border-radius: var(--radius-xl);
  background:
    linear-gradient(135deg, rgba(36, 87, 230, 0.08), transparent 48%),
    var(--panel-strong);
  box-shadow: var(--shadow-soft);
}

.html-history-section {
  padding: clamp(1rem, 2vw, 1.35rem);
  border: 1px solid var(--border);
  border-radius: var(--radius-xl);
  background:
    linear-gradient(135deg, rgba(255, 204, 102, 0.16), transparent 46%),
    var(--panel-strong);
  box-shadow: var(--shadow-soft);
}

.html-path-section {
  padding: clamp(1rem, 2vw, 1.35rem);
  border: 1px solid var(--border);
  border-radius: var(--radius-xl);
  background:
    linear-gradient(135deg, rgba(18, 128, 92, 0.1), transparent 48%),
    var(--panel-strong);
  box-shadow: var(--shadow-soft);
}

.html-section-menu {
  display: flex;
  flex-wrap: wrap;
  gap: 0.55rem;
  align-items: center;
  padding: 0.85rem;
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  background: var(--panel-strong);
  box-shadow: var(--shadow-soft);
}

.html-section-menu a {
  display: inline-flex;
  align-items: center;
  min-height: 2.4rem;
  padding: 0.55rem 0.75rem;
  border: 1px solid var(--border);
  border-radius: 999px;
  color: var(--muted);
  background: var(--panel);
  font-size: 0.9rem;
  font-weight: 850;
  text-decoration: none;
}

.html-section-menu a:hover,
.html-section-menu a:focus-visible {
  color: var(--primary-deep);
  border-color: rgba(36, 87, 230, 0.42);
  background: rgba(36, 87, 230, 0.08);
}

.html-section-menu a.is-current {
  color: white;
  border-color: transparent;
  background: linear-gradient(135deg, var(--primary), var(--green));
}

.section-divider {
  width: 100%;
  margin: 0.5rem 0 0;
  border: 0;
  border-top: 1px solid var(--border);
}

#basicTagsOneRecapHeading,
.quick-recap-heading {
  color: var(--danger);
  font-size: 1.35rem;
}

.html-path-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 1rem;
  margin: 0;
  padding: 0;
  list-style: none;
}

.html-path-grid li {
  min-width: 0;
}

.html-path-grid a {
  display: grid;
  gap: 0.45rem;
  height: 100%;
  padding: 1rem;
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  color: inherit;
  background: var(--panel);
  text-decoration: none;
  box-shadow: var(--shadow-soft);
}

.html-path-grid a:hover,
.html-path-grid a:focus-visible {
  border-color: var(--primary);
  transform: translateY(-1px);
}

.html-path-grid strong {
  color: var(--text);
}

.html-path-grid span {
  color: var(--muted);
  line-height: 1.45;
}

.html-path-grid .is-current a {
  border-color: var(--primary);
  background:
    linear-gradient(135deg, rgba(36, 87, 230, 0.12), transparent 60%),
    var(--panel-strong);
}

.html-path-section h1,
.html-software-section h1,
.html-reference-section h1,
.file-path-section h1,
.html-playground-card h1 {
  max-width: 16ch;
  font-size: clamp(2.4rem, 6vw, 4.2rem);
}

.github-collaboration-title {
  max-width: 13ch;
  font-size: clamp(2.65rem, 6.5vw, 4.8rem);
}

.history-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 1rem;
}

.html-software-section {
  display: grid;
  gap: 1rem;
  margin-top: 1rem;
}

.software-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1rem;
}

.software-list {
  display: grid;
  gap: 0.85rem;
  margin: 0.8rem 0 0;
  padding: 0;
  list-style: none;
}

.software-list li {
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto;
  gap: 0.75rem;
  align-items: start;
  padding: 0.75rem;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  background: var(--panel);
}

.software-list strong {
  display: block;
  margin-bottom: 0.25rem;
  color: var(--text);
}

.software-list a {
  color: var(--primary-deep);
  text-underline-offset: 0.18em;
}

.software-list a:hover,
.software-list a:focus-visible {
  color: var(--purple);
}

.software-list p {
  margin: 0;
}

.html-explainer-grid,
.tag-reference-grid {
  display: grid;
  gap: 1rem;
}

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

.file-path-section {
  display: grid;
  gap: 1rem;
  padding: 1rem;
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  background:
    linear-gradient(135deg, rgba(123, 63, 242, 0.08), transparent 48%),
    var(--panel);
}

.path-explainer-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 1rem;
}

.path-explainer-grid .info-card {
  min-width: 0;
}

.file-path-section .code-box {
  max-width: 100%;
  overflow-x: hidden;
  white-space: pre-wrap;
  word-break: break-word;
}

.file-path-section .code-box code {
  white-space: inherit;
  overflow-wrap: anywhere;
  word-break: break-word;
}

.tag-reference-heading {
  margin-top: 0.5rem;
}

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

.tag-card {
  padding: 1rem;
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  background: var(--panel);
  box-shadow: var(--shadow-soft);
}

.tag-card summary {
  display: flex;
  flex-wrap: wrap;
  gap: 0.65rem;
  align-items: center;
  cursor: pointer;
  font-weight: 850;
}

.tag-card summary span {
  color: var(--muted);
  font-weight: 750;
}

.tag-card p {
  color: var(--muted);
  line-height: 1.55;
}

.tag-card code,
.html-reference-section code {
  border-radius: 0.35rem;
  padding: 0.05rem 0.25rem;
  background: rgba(36, 87, 230, 0.1);
  overflow-wrap: anywhere;
}

.tag-card .code-box code,
.html-reference-section .code-box code {
  padding: 0;
  background: transparent;
}

.attribute-list {
  display: grid;
  gap: 0.55rem;
  margin: 0.8rem 0;
}

.attribute-list div {
  display: grid;
  grid-template-columns: minmax(7rem, 0.35fr) minmax(0, 1fr);
  gap: 0.65rem;
  padding: 0.65rem;
  border-radius: var(--radius-md);
  background: rgba(18, 128, 92, 0.08);
}

.attribute-list dt {
  color: var(--text);
  font-weight: 850;
}

.attribute-list dd {
  margin: 0;
  color: var(--muted);
  line-height: 1.45;
}

.html-practice-notes {
  margin-top: 0;
}

.html-basic-tags-section {
  display: grid;
  gap: 1rem;
}

.html-tag-practice-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 1rem;
}

.html-tag-card {
  display: grid;
  align-content: start;
  gap: 0.45rem;
  padding: 1rem;
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  background: var(--panel);
  box-shadow: var(--shadow-soft);
}

.html-wide-card {
  grid-column: 1 / -1;
}

.html-tag-card h3,
.html-tag-card p {
  margin: 0;
}

.html-tag-card p {
  color: var(--muted);
  line-height: 1.5;
}

.html-basic-tags-section code,
.html-basic-tags-card code {
  border-radius: 0.35rem;
  padding: 0.05rem 0.25rem;
  background: rgba(36, 87, 230, 0.1);
  overflow-wrap: anywhere;
}

.html-basic-tags-section .code-box code,
.html-basic-tags-card .code-box code {
  padding: 0;
  background: transparent;
}

.html-playground-card {
  display: grid;
  gap: 1rem;
  padding: 1rem;
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  background: var(--panel);
  box-shadow: var(--shadow-soft);
}

.html-playground-layout {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(18rem, 0.9fr);
  gap: 1rem;
  align-items: stretch;
}

.html-playground-editor {
  display: grid;
  gap: 0.5rem;
  color: var(--text);
  font-weight: 850;
}

.html-playground-editor textarea {
  width: 100%;
  min-height: 29rem;
  resize: vertical;
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  padding: 1rem;
  color: var(--text);
  background: #f3f6ff;
  font-family: "SFMono-Regular", Consolas, "Liberation Mono", monospace;
  font-size: 0.92rem;
  line-height: 1.5;
  tab-size: 2;
}

:root[data-theme="dark"] .html-playground-editor textarea {
  background: #10182a;
}

.html-playground-preview-panel {
  display: grid;
  grid-template-rows: auto minmax(0, 1fr);
  gap: 0.5rem;
  min-height: 29rem;
}

.html-playground-preview-panel h3,
.html-playground-preview-panel h4 {
  margin: 0;
}

.html-playground-preview-panel iframe {
  width: 100%;
  min-height: 27rem;
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  background: white;
}

.html-playground-feedback {
  display: grid;
  gap: 0.8rem;
}

.code-playground-card {
  display: grid;
  gap: 1rem;
  padding: clamp(1rem, 2vw, 1.35rem);
  border: 1px solid var(--border);
  border-radius: var(--radius-xl);
  background:
    linear-gradient(135deg, rgba(36, 87, 230, 0.08), transparent 48%),
    var(--panel-strong);
  box-shadow: var(--shadow-soft);
}

.code-playground-layout {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(18rem, 0.9fr);
  gap: 1rem;
  align-items: stretch;
}

.code-playground-editor {
  display: grid;
  gap: 0.5rem;
  color: var(--text);
  font-weight: 850;
}

.code-playground-editor textarea {
  width: 100%;
  min-height: 29rem;
  resize: vertical;
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  padding: 1rem;
  color: var(--text);
  background: #f3f6ff;
  font-family: "SFMono-Regular", Consolas, "Liberation Mono", monospace;
  font-size: 0.92rem;
  line-height: 1.5;
  tab-size: 2;
}

:root[data-theme="dark"] .code-playground-editor textarea {
  background: #10182a;
}

.code-playground-preview-panel {
  display: grid;
  grid-template-rows: auto minmax(0, 1fr);
  gap: 0.5rem;
  min-height: 29rem;
}

.code-playground-preview-panel h3 {
  margin: 0;
}

.code-playground-preview-panel iframe {
  width: 100%;
  min-height: 27rem;
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  background: white;
}

.code-playground-feedback {
  display: grid;
  gap: 0.8rem;
}

.design-reference-section {
  display: grid;
  gap: 1rem;
  padding: clamp(1rem, 2vw, 1.35rem);
  border: 1px solid var(--border);
  border-radius: var(--radius-xl);
  background:
    linear-gradient(135deg, rgba(123, 63, 242, 0.08), transparent 48%),
    var(--panel-strong);
  box-shadow: var(--shadow-soft);
}

.design-concept-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1rem;
  align-items: stretch;
}

.design-concept-grid .tag-card {
  height: 100%;
}

.design-card-body {
  display: grid;
  grid-template-columns: minmax(6.5rem, 0.38fr) minmax(0, 1fr);
  gap: 0.85rem;
  align-items: start;
  margin-top: 0.9rem;
}

.design-card-copy {
  display: grid;
  gap: 0.75rem;
  min-width: 0;
}

.design-card-copy p {
  margin: 0;
}

.design-card-links {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  margin: 0;
  padding: 0;
  list-style: none;
}

.design-card-links a {
  display: inline-flex;
  align-items: center;
  min-height: 2.35rem;
  padding: 0.45rem 0.7rem;
  border: 1px solid rgba(36, 87, 230, 0.2);
  border-radius: 999px;
  color: var(--primary-deep);
  background: rgba(36, 87, 230, 0.08);
  font-size: 0.86rem;
  font-weight: 850;
  text-decoration: none;
}

.design-card-links a:hover,
.design-card-links a:focus-visible {
  border-color: rgba(36, 87, 230, 0.42);
  background: rgba(36, 87, 230, 0.14);
}

:root[data-theme="dark"] .design-card-links a {
  color: var(--primary-deep);
  border-color: rgba(143, 177, 255, 0.28);
  background: rgba(143, 177, 255, 0.1);
}

.design-card-visual {
  position: relative;
  display: grid;
  place-items: center;
  min-height: 8rem;
  padding: 0.8rem;
  overflow: hidden;
  border: 1px solid rgba(123, 63, 242, 0.18);
  border-radius: var(--radius-md);
  background:
    radial-gradient(circle at 22% 18%, rgba(123, 63, 242, 0.18), transparent 30%),
    radial-gradient(circle at 82% 78%, rgba(18, 128, 92, 0.14), transparent 28%),
    #f6f8ff;
}

:root[data-theme="dark"] .design-card-visual {
  background:
    radial-gradient(circle at 22% 18%, rgba(143, 177, 255, 0.18), transparent 30%),
    radial-gradient(circle at 82% 78%, rgba(130, 222, 184, 0.12), transparent 28%),
    #111a2d;
}

.design-card-visual span {
  display: block;
}

.visual-frame,
.visual-text-block,
.visual-type,
.visual-space,
.visual-image,
.visual-gauge {
  width: min(100%, 8rem);
}

.visual-window,
.visual-text-block,
.visual-type {
  display: grid;
  gap: 0.45rem;
  padding: 0.8rem;
  border: 2px solid var(--primary);
  border-radius: 1rem;
  background: var(--panel-strong);
  box-shadow: var(--shadow-soft);
}

.visual-bar,
.visual-line,
.visual-button {
  border-radius: 999px;
}

.visual-bar {
  height: 0.55rem;
  background: var(--purple);
}

.visual-line {
  height: 0.45rem;
  background: rgba(95, 111, 137, 0.38);
}

.visual-line-short {
  width: 64%;
}

.visual-line-strong {
  height: 0.7rem;
  background: var(--text);
}

.visual-button {
  width: 56%;
  height: 1.3rem;
  background: var(--green);
}

.visual-journey,
.visual-devices,
.visual-patterns,
.visual-swatches,
.visual-theme-pair,
.visual-icons,
.visual-vector,
.visual-hierarchy,
.visual-consistency {
  display: flex;
  align-items: center;
  justify-content: center;
  width: min(100%, 8rem);
}

.visual-dot {
  width: 1.35rem;
  height: 1.35rem;
  border-radius: 999px;
  background: var(--primary);
  box-shadow: 0 0 0 0.35rem rgba(36, 87, 230, 0.12);
}

.visual-dot-accent {
  background: var(--purple);
}

.visual-dot-green {
  background: var(--green);
}

.visual-path {
  width: 1.6rem;
  height: 0.22rem;
  background: rgba(95, 111, 137, 0.5);
}

.visual-devices {
  align-items: end;
  gap: 0.45rem;
}

.visual-device {
  border: 2px solid var(--primary);
  border-radius: 0.55rem;
  background: var(--panel-strong);
}

.visual-phone {
  width: 1.55rem;
  height: 3.7rem;
}

.visual-tablet {
  width: 2.4rem;
  height: 4.7rem;
}

.visual-desktop {
  width: 4rem;
  height: 3rem;
}

.visual-type strong {
  color: var(--primary-deep);
  font-size: 2.8rem;
  line-height: 0.9;
}

.visual-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 0.35rem;
  width: min(100%, 7rem);
}

.visual-grid span,
.visual-consistency span {
  min-height: 1.35rem;
  border-radius: 0.45rem;
  background: rgba(36, 87, 230, 0.18);
}

.visual-grid span:nth-child(2n),
.visual-consistency span:nth-child(2) {
  background: rgba(18, 128, 92, 0.2);
}

.visual-patterns {
  gap: 1rem;
}

.visual-f-path,
.visual-z-path {
  position: relative;
  width: 3rem;
  height: 4.2rem;
}

.visual-f-path::before,
.visual-f-path::after,
.visual-z-path::before,
.visual-z-path::after {
  position: absolute;
  content: "";
  border-radius: 999px;
  background: var(--primary);
}

.visual-f-path::before {
  inset: 0 auto 0 0;
  width: 0.45rem;
}

.visual-f-path::after {
  top: 0;
  left: 0;
  width: 100%;
  height: 0.45rem;
  box-shadow: 0 1.85rem 0 rgba(36, 87, 230, 0.55);
}

.visual-z-path::before {
  left: 0;
  right: 0;
  top: 0;
  height: 0.45rem;
  box-shadow: 0 3.75rem 0 rgba(36, 87, 230, 0.65);
}

.visual-z-path::after {
  top: 1.9rem;
  left: -0.15rem;
  width: 3.4rem;
  height: 0.45rem;
  transform: rotate(-42deg);
}

.visual-space {
  display: grid;
  place-items: center;
  min-height: 5.8rem;
  border: 2px dashed rgba(95, 111, 137, 0.38);
  border-radius: 1.1rem;
  background: rgba(255, 255, 255, 0.5);
}

.visual-space span {
  width: 45%;
  height: 2.25rem;
  border-radius: 0.65rem;
  background: var(--primary);
}

.visual-swatches {
  gap: 0.5rem;
}

.visual-swatches span {
  width: 1.55rem;
  height: 4.6rem;
  border-radius: 999px;
}

.visual-swatches span:nth-child(1) {
  background: #2457e6;
}

.visual-swatches span:nth-child(2) {
  background: #7b3ff2;
}

.visual-swatches span:nth-child(3) {
  background: #12805c;
}

.visual-swatches span:nth-child(4) {
  background: #ffcc66;
}

.visual-theme-pair {
  gap: 0.6rem;
}

.visual-theme-pair span {
  width: 3.25rem;
  height: 4.6rem;
  border-radius: 1rem;
  border: 2px solid var(--border);
}

.visual-theme-pair span:first-child {
  background: #ffffff;
}

.visual-theme-pair span:last-child {
  background: #182033;
}

.visual-icons {
  gap: 0.55rem;
}

.visual-icons span {
  width: 2.05rem;
  height: 2.05rem;
  border-radius: 0.65rem;
  background: var(--primary);
}

.visual-icons span:nth-child(2) {
  border-radius: 999px;
  background: var(--green);
}

.visual-icons span:nth-child(3) {
  clip-path: polygon(50% 0, 100% 100%, 0 100%);
  border-radius: 0;
  background: var(--purple);
}

.visual-vector {
  position: relative;
  height: 5rem;
}

.visual-vector::before {
  position: absolute;
  top: 2.35rem;
  left: 0.7rem;
  width: 6.7rem;
  height: 0.3rem;
  content: "";
  border-radius: 999px;
  background: var(--primary);
  transform: rotate(-15deg);
}

.visual-vector span {
  position: relative;
  z-index: 1;
  width: 1rem;
  height: 1rem;
  border-radius: 999px;
  background: var(--green);
}

.visual-vector span:nth-child(2) {
  margin-inline: 1.55rem;
  transform: translateY(-0.9rem);
}

.visual-image {
  position: relative;
  height: 5.8rem;
  border: 2px solid var(--primary);
  border-radius: 1rem;
  background: linear-gradient(180deg, rgba(36, 87, 230, 0.16), rgba(18, 128, 92, 0.12));
}

.visual-sun {
  position: absolute;
  top: 0.7rem;
  right: 0.8rem;
  width: 1rem;
  height: 1rem;
  border-radius: 999px;
  background: var(--yellow);
}

.visual-mountain {
  position: absolute;
  bottom: 0;
  width: 55%;
  height: 52%;
  clip-path: polygon(50% 0, 100% 100%, 0 100%);
  background: var(--green);
}

.visual-mountain-one {
  left: 0.5rem;
}

.visual-mountain-two {
  right: 0.6rem;
  opacity: 0.72;
}

.visual-gauge {
  position: relative;
  height: 5.1rem;
  border-radius: 5.1rem 5.1rem 0 0;
  border: 0.7rem solid rgba(36, 87, 230, 0.18);
  border-bottom: 0;
}

.visual-gauge span {
  position: absolute;
  bottom: 0.1rem;
  left: 50%;
  width: 3.2rem;
  height: 0.28rem;
  border-radius: 999px;
  background: var(--danger);
  transform: translateX(-10%) rotate(-28deg);
  transform-origin: left center;
}

.visual-hierarchy {
  flex-direction: column;
  align-items: flex-start;
  gap: 0.55rem;
}

.visual-hierarchy span {
  height: 0.75rem;
  border-radius: 999px;
  background: var(--primary);
}

.visual-hierarchy span:nth-child(1) {
  width: 7.4rem;
  height: 1.25rem;
}

.visual-hierarchy span:nth-child(2) {
  width: 5.5rem;
  background: var(--purple);
}

.visual-hierarchy span:nth-child(3) {
  width: 4rem;
  background: rgba(95, 111, 137, 0.44);
}

.visual-consistency {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 0.45rem;
}

.design-checklist-panel {
  padding: 1rem;
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  background: rgba(18, 128, 92, 0.08);
}

.design-checklist-panel h3 {
  margin-top: 0;
}

.website-design-section {
  display: grid;
  gap: 1.15rem;
  padding: clamp(1rem, 2vw, 1.35rem);
  border: 1px solid var(--border);
  border-radius: var(--radius-xl);
  background:
    linear-gradient(135deg, rgba(18, 128, 92, 0.08), transparent 48%),
    var(--panel-strong);
  box-shadow: var(--shadow-soft);
}

.website-design-flow {
  display: grid;
  grid-template-columns: repeat(5, minmax(0, 1fr));
  gap: 0.75rem;
}

.website-design-flow article,
.site-map-panel,
.wireframe-panel,
.example-site-card {
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  background: var(--panel);
  box-shadow: var(--shadow-soft);
}

.website-design-flow article {
  position: relative;
  display: grid;
  gap: 0.55rem;
  align-content: start;
  padding: 1rem;
}

.workflow-step-number {
  display: inline-grid;
  place-items: center;
  width: 2.1rem;
  height: 2.1rem;
  border-radius: 999px;
  color: white;
  background: linear-gradient(135deg, var(--primary), var(--purple));
  font-weight: 900;
}

.website-design-flow h3,
.site-map-panel h3,
.wireframe-panel h3,
.design-system-panel h3,
.example-site-card h4 {
  margin: 0;
}

.website-design-flow p,
.site-map-panel p,
.wireframe-panel p,
.design-system-panel p,
.example-site-card p {
  margin: 0;
  color: var(--muted);
  line-height: 1.55;
}

.website-design-lab {
  display: grid;
  grid-template-columns: minmax(0, 0.95fr) minmax(0, 1.05fr);
  gap: 1rem;
  align-items: stretch;
}

.site-map-panel,
.wireframe-panel {
  display: grid;
  gap: 0.9rem;
  padding: 1rem;
}

.site-map-diagram {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 0.75rem;
  padding: 1rem;
  border-radius: var(--radius-lg);
  background: rgba(36, 87, 230, 0.08);
}

.site-node {
  position: relative;
  display: grid;
  place-items: center;
  min-height: 3rem;
  border: 2px solid rgba(36, 87, 230, 0.24);
  border-radius: var(--radius-md);
  color: var(--text);
  background: var(--panel-strong);
  font-weight: 900;
  text-align: center;
}

.site-node-home {
  grid-column: 1 / -1;
  justify-self: center;
  min-width: min(12rem, 100%);
  color: white;
  border-color: transparent;
  background: linear-gradient(135deg, var(--primary), var(--green));
}

.site-node-home::after {
  position: absolute;
  top: calc(100% + 0.2rem);
  left: 50%;
  width: 2px;
  height: 0.55rem;
  content: "";
  background: rgba(36, 87, 230, 0.45);
}

.wireframe-pair {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(5.5rem, 0.38fr);
  gap: 0.75rem;
  align-items: stretch;
}

.wireframe {
  display: grid;
  gap: 0.55rem;
  padding: 0.75rem;
  border: 2px solid rgba(123, 63, 242, 0.22);
  border-radius: var(--radius-lg);
  background:
    linear-gradient(135deg, rgba(123, 63, 242, 0.08), transparent),
    var(--panel-strong);
}

.wireframe span {
  border-radius: 0.6rem;
  background: rgba(95, 111, 137, 0.2);
}

.wireframe-desktop {
  grid-template-columns: repeat(3, minmax(0, 1fr));
  min-height: 12rem;
}

.wireframe-mobile {
  min-height: 12rem;
}

.wire-nav,
.wire-hero,
.wire-footer {
  grid-column: 1 / -1;
}

.wire-nav {
  min-height: 1.4rem;
  background: var(--primary) !important;
}

.wire-hero {
  min-height: 3rem;
  background: rgba(18, 128, 92, 0.22) !important;
}

.wire-card {
  min-height: 4rem;
}

.wire-footer {
  min-height: 1.8rem;
  background: rgba(123, 63, 242, 0.2) !important;
}

.design-system-panel {
  display: grid;
  grid-template-columns: minmax(0, 0.48fr) minmax(0, 1fr);
  gap: 1rem;
  padding: 1rem;
  border: 1px solid rgba(18, 128, 92, 0.22);
  border-radius: var(--radius-lg);
  background: rgba(18, 128, 92, 0.08);
}

.design-system-list {
  display: grid;
  gap: 0.65rem;
  margin: 0;
  padding: 0;
  list-style: none;
}

.design-system-list li {
  padding: 0.75rem;
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  background: var(--panel-strong);
  color: var(--muted);
  line-height: 1.5;
}

.design-system-list strong {
  color: var(--text);
}

.compact-heading {
  gap: 0.35rem;
  margin-top: 0.25rem;
}

.compact-heading h3 {
  margin: 0;
  font-size: 1.45rem;
}

.example-site-section,
.design-helper-section {
  display: grid;
  gap: 0.9rem;
}

.example-site-grid,
.design-helper-grid {
  display: grid;
  gap: 0.75rem;
}

.example-site-grid {
  grid-template-columns: repeat(5, minmax(0, 1fr));
}

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

.example-site-card {
  display: grid;
  gap: 0.7rem;
  align-content: start;
  padding: 1rem;
}

.design-helper-card {
  display: grid;
  gap: 0.7rem;
  align-content: start;
  padding: 1rem;
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  background: var(--panel);
  box-shadow: var(--shadow-soft);
}

.design-helper-top {
  display: flex;
  flex-wrap: wrap;
  gap: 0.6rem;
  align-items: center;
  justify-content: space-between;
}

.design-helper-top h4 {
  margin: 0;
  font-size: 1.1rem;
}

.design-helper-top span {
  padding: 0.35rem 0.55rem;
  border-radius: 999px;
  color: var(--green);
  background: rgba(18, 128, 92, 0.1);
  font-size: 0.78rem;
  font-weight: 900;
}

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

.design-helper-card strong {
  color: var(--text);
}

.example-site-card a {
  align-self: end;
  justify-self: start;
  padding: 0.48rem 0.7rem;
  border: 1px solid rgba(36, 87, 230, 0.2);
  border-radius: 999px;
  color: var(--primary-deep);
  background: rgba(36, 87, 230, 0.08);
  font-size: 0.86rem;
  font-weight: 850;
  text-decoration: none;
}

.design-helper-card a {
  align-self: end;
  justify-self: start;
  padding: 0.48rem 0.7rem;
  border: 1px solid rgba(36, 87, 230, 0.2);
  border-radius: 999px;
  color: var(--primary-deep);
  background: rgba(36, 87, 230, 0.08);
  font-size: 0.86rem;
  font-weight: 850;
  text-decoration: none;
}

.example-site-card a:hover,
.example-site-card a:focus-visible,
.design-helper-card a:hover,
.design-helper-card a:focus-visible {
  border-color: rgba(36, 87, 230, 0.42);
  background: rgba(36, 87, 230, 0.14);
}

:root[data-theme="dark"] .example-site-card a,
:root[data-theme="dark"] .design-helper-card a {
  color: var(--primary-deep);
  border-color: rgba(143, 177, 255, 0.28);
  background: rgba(143, 177, 255, 0.1);
}

.prompt-card,
.comparison-card,
.challenge-card,
.debug-card,
.reflection-card {
  padding: 1rem;
}

.prompt-box,
.code-box {
  position: relative;
  margin: 0.75rem 0;
  padding: 1rem;
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  color: var(--text);
  background: #f3f6ff;
  line-height: 1.55;
  white-space: pre-wrap;
}

:root[data-theme="dark"] .prompt-box,
:root[data-theme="dark"] .code-box {
  background: #10182a;
}

.comparison-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 0.75rem;
}

.comparison-card .weak {
  border-left: 4px solid var(--danger);
}

.comparison-card .improved {
  border-left: 4px solid var(--green);
}

.hidden-panel {
  display: none;
  box-sizing: border-box;
  max-width: 100%;
  margin-top: 0.8rem;
  padding: 0.85rem;
  border-radius: var(--radius-md);
  color: var(--muted);
  background: rgba(18, 128, 92, 0.09);
  line-height: 1.55;
  overflow-wrap: anywhere;
}

.hidden-panel.is-visible {
  display: block;
}

pre.hidden-panel {
  margin-bottom: 0;
  overflow-x: auto;
  white-space: pre-wrap;
}

pre.hidden-panel code {
  white-space: inherit;
  overflow-wrap: anywhere;
}

.quiz-card {
  padding: 1rem;
  border: 1px dashed var(--border);
  border-radius: var(--radius-lg);
  background: rgba(123, 63, 242, 0.08);
}

.quiz-options {
  display: grid;
  gap: 0.55rem;
  margin-top: 0.75rem;
}

.quiz-options button {
  width: 100%;
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  padding: 0.75rem;
  color: var(--text);
  background: var(--panel-strong);
  cursor: pointer;
  text-align: left;
}

.quiz-options button.is-correct {
  border-color: var(--green);
  background: rgba(18, 128, 92, 0.12);
}

.quiz-options button.is-wrong {
  border-color: var(--danger);
  background: rgba(177, 60, 74, 0.1);
}

.quiz-feedback {
  min-height: 1.4rem;
  margin: 0.75rem 0 0;
  color: var(--muted);
  font-weight: 750;
}

/* Project templates, tool cards, glossary, and teacher resources */
.template-list {
  display: grid;
  gap: 2rem;
}

.template-group {
  display: grid;
  gap: 1rem;
}

.template-group-heading {
  padding: 1rem;
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  background: var(--panel-strong);
}

.template-group-heading h2 {
  margin-bottom: 0.35rem;
}

.template-group-heading p {
  max-width: 68ch;
  margin: 0;
  color: var(--muted);
  line-height: 1.55;
}

.template-group-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1rem;
}

.template-card {
  overflow: hidden;
}

.template-card summary {
  display: grid;
  gap: 0.5rem;
  padding: 1rem;
  cursor: pointer;
}

.template-card-title {
  color: var(--text);
  font-weight: 850;
}

.template-card-description {
  color: var(--muted);
  line-height: 1.5;
}

.template-card pre {
  max-height: 28rem;
  margin: 0;
  overflow: auto;
  padding: 1rem;
  background: #10182a;
  color: #f3f7ff;
  line-height: 1.5;
}

.template-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
  justify-content: end;
  align-items: center;
  padding: 0 1rem 1rem;
}

.filter-panel {
  display: grid;
  grid-template-columns: minmax(240px, 0.5fr) minmax(0, 1fr);
  gap: 1rem;
  align-items: end;
  margin-bottom: 1rem;
}

.search-field {
  display: grid;
  gap: 0.4rem;
  color: var(--text);
  font-weight: 850;
}

.search-field input {
  width: 100%;
  border: 1px solid var(--border);
  border-radius: 999px;
  padding: 0.85rem 1rem;
  color: var(--text);
  background: var(--panel-strong);
}

.filter-button {
  border: 1px solid var(--border);
  border-radius: 999px;
  padding: 0.7rem 0.85rem;
  color: var(--muted);
  background: var(--panel-strong);
  font-weight: 800;
  cursor: pointer;
}

.filter-button.is-active {
  color: white;
  border-color: transparent;
  background: linear-gradient(135deg, var(--primary), var(--purple));
}

.tool-grid,
.glossary-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 1rem;
}

.tool-card,
.term-card {
  padding: 1rem;
}

.glossary-page-section h1,
.tools-page-section h1,
.templates-page-section h1,
.teacher-page-section h1 {
  max-width: 16ch;
  font-size: clamp(2.4rem, 6vw, 4.2rem);
}

.tool-card h3,
.term-card h3 {
  margin-bottom: 0.65rem;
}

.tool-card h3 a {
  color: var(--primary-deep);
  text-decoration-thickness: 2px;
  text-underline-offset: 0.22em;
}

.tool-card p,
.term-card p {
  color: var(--muted);
  line-height: 1.55;
}

.tool-meta {
  display: grid;
  gap: 0.5rem;
  margin: 0.8rem 0;
}

.tool-meta p {
  margin: 0;
}

.tag-row {
  display: flex;
  flex-wrap: wrap;
  gap: 0.45rem;
}

.tag {
  padding: 0.35rem 0.55rem;
  border-radius: 999px;
  color: var(--primary-deep);
  background: rgba(36, 87, 230, 0.1);
  font-size: 0.82rem;
  font-weight: 850;
}

.local-file-demo h3 {
  margin: 0 0 0.35rem;
}

.local-file-demo p {
  color: var(--muted);
  line-height: 1.65;
}

.file-demo-input {
  display: grid;
  gap: 0.5rem;
  color: var(--text);
  font-weight: 850;
}

.file-demo-input input[type="file"] {
  width: 100%;
  border: 1px dashed var(--border);
  border-radius: var(--radius-md);
  padding: 1rem;
  color: var(--text);
  background: var(--panel-strong);
}

.file-demo-status {
  margin: 0;
  padding: 0.9rem 1rem;
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  background: rgba(36, 87, 230, 0.08);
  font-weight: 750;
}

.glossary-search {
  max-width: 38rem;
  margin-bottom: 1rem;
}

.teacher-section {
  margin-bottom: 2rem;
}

.rubric-card {
  margin-top: 1rem;
  padding: 1rem;
}

.rubric-header {
  justify-content: space-between;
  margin-bottom: 1rem;
}

.rubric-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
  align-items: center;
}

.table-wrap {
  overflow-x: auto;
}

table {
  width: 100%;
  border-collapse: collapse;
  min-width: 760px;
}

th,
td {
  padding: 0.8rem;
  border: 1px solid var(--border);
  text-align: left;
  vertical-align: top;
  line-height: 1.5;
}

th {
  color: var(--text);
  background: rgba(36, 87, 230, 0.08);
}

.back-to-top {
  position: fixed;
  right: 1rem;
  bottom: 1rem;
  z-index: 40;
  display: none;
  border: 0;
  border-radius: 999px;
  padding: 0.8rem 1rem;
  color: white;
  background: linear-gradient(135deg, var(--primary), var(--purple));
  box-shadow: var(--shadow-soft);
  font-weight: 850;
  cursor: pointer;
}

.back-to-top.is-visible {
  display: inline-flex;
}

.toast {
  position: fixed;
  left: 50%;
  bottom: 1.1rem;
  z-index: 60;
  transform: translate(-50%, 150%);
  padding: 0.8rem 1rem;
  border-radius: 999px;
  color: white;
  background: #182033;
  box-shadow: var(--shadow);
  font-weight: 800;
  transition: transform 180ms ease;
}

.toast.is-visible {
  transform: translate(-50%, 0);
}

@media (max-width: 980px) {
  .hero-section,
  .two-column-section,
  .lesson-layout,
  .filter-panel,
  .teacher-grid,
  .website-design-lab,
  .design-system-panel,
  .project-planning-lab {
    grid-template-columns: 1fr;
  }

  .category-grid,
  .tool-grid,
  .glossary-grid,
  .template-list,
  .template-group-grid,
  .prompt-strategy-grid,
  .design-step-grid,
  .design-review-grid,
  .html-explainer-grid,
  .html-tag-practice-grid,
  .tag-reference-grid,
  .html-playground-layout,
  .code-playground-layout,
  .html-path-grid,
  .history-grid,
  .software-grid,
  .path-explainer-grid,
  .design-concept-grid,
  .website-design-flow,
  .example-site-grid,
  .design-helper-grid,
  .project-level-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

@media (max-width: 760px) {
  .site-header {
    padding: 0.65rem 0.75rem;
  }

  .menu-button {
    display: inline-flex;
  }

  .nav-actions {
    display: none;
  }

  .progress-strip {
    grid-template-columns: 1fr;
  }

  .category-nav {
    display: none;
    flex-direction: column;
    max-height: 70vh;
    overflow-y: auto;
  }

  .category-nav.is-open {
    display: flex;
  }

  main {
    padding-inline: 0.75rem;
  }

  h1 {
    font-size: clamp(3rem, 18vw, 4.7rem);
  }

  .category-grid,
  .tool-grid,
  .glossary-grid,
  .template-list,
  .template-group-grid,
  .comparison-grid,
  .prompt-strategy-grid,
  .prompt-review-grid,
  .design-step-grid,
  .design-review-grid,
  .html-explainer-grid,
  .html-tag-practice-grid,
  .tag-reference-grid,
  .html-playground-layout,
  .code-playground-layout,
  .html-path-grid,
  .history-grid,
  .software-grid,
  .path-explainer-grid,
  .design-concept-grid,
  .website-design-flow,
  .example-site-grid,
  .design-helper-grid,
  .project-level-grid {
    grid-template-columns: 1fr;
  }

  .software-list li {
    grid-template-columns: 1fr;
  }

  .html-section-menu a {
    width: 100%;
  }

  .design-card-body {
    grid-template-columns: 1fr;
  }

  .design-card-visual {
    min-height: 7rem;
  }

  .site-map-diagram,
  .wireframe-pair {
    grid-template-columns: 1fr;
  }

  .attribute-list div {
    grid-template-columns: 1fr;
  }

  .lesson-header,
  .rubric-header {
    grid-template-columns: 1fr;
  }

  .lesson-page-intro,
  .lesson-pager {
    align-items: stretch;
    flex-direction: column;
  }

  .completion-control,
  .button,
  .filter-button {
    width: 100%;
  }
}