:root {
  color-scheme: light;
  --bg: #f6f8fb;
  --panel: #ffffff;
  --ink: #16202a;
  --muted: #5b6673;
  --line: #d9e0e8;
  --blue: #326ce5;
  --blue-dark: #204d9a;
  --teal: #0f766e;
  --gold: #9a6700;
  --red: #b42318;
  --green: #166534;
  --shadow: 0 14px 35px rgba(25, 37, 52, 0.08);
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  line-height: 1.55;
}

a {
  color: inherit;
}

.app-shell {
  display: grid;
  grid-template-columns: 320px minmax(0, 1fr);
  min-height: 100vh;
}

.sidebar {
  position: sticky;
  top: 0;
  height: 100vh;
  overflow-y: auto;
  border-right: 1px solid var(--line);
  background: #fff;
  padding: 22px;
  z-index: 5;
}

.brand {
  display: flex;
  gap: 12px;
  align-items: center;
  text-decoration: none;
  margin-bottom: 24px;
}

.brand-mark {
  display: grid;
  place-items: center;
  width: 48px;
  height: 48px;
  border-radius: 8px;
  background: var(--blue);
  color: #fff;
  font-weight: 800;
}

.brand strong {
  display: block;
  font-size: 1.05rem;
}

.brand small,
.eyebrow,
.nav-group-title,
.search-box span {
  color: var(--muted);
  font-size: 0.78rem;
  letter-spacing: 0;
  text-transform: uppercase;
}

.search-box {
  display: grid;
  gap: 8px;
  margin-bottom: 20px;
}

.search-box input {
  width: 100%;
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 12px 13px;
  font: inherit;
  color: var(--ink);
  background: #f9fbfd;
}

.search-box input:focus {
  outline: 3px solid rgba(50, 108, 229, 0.16);
  border-color: var(--blue);
}

.nav-group-title {
  margin: 18px 0 10px;
  font-weight: 800;
}

.topic-nav {
  display: grid;
  gap: 6px;
}

.nav-track {
  border: 1px solid var(--line);
  border-radius: 8px;
  background: #fbfdff;
  margin-bottom: 8px;
}

.nav-track summary {
  display: grid;
  grid-template-columns: 38px 1fr;
  gap: 10px;
  align-items: center;
  min-height: 52px;
  padding: 10px 11px;
  cursor: pointer;
  list-style: none;
}

.nav-track summary::-webkit-details-marker {
  display: none;
}

.nav-track summary::after {
  content: "+";
  grid-column: 1 / -1;
  display: none;
}

.nav-track summary strong,
.nav-track summary small {
  display: block;
}

.nav-track summary small {
  color: var(--muted);
  font-size: 0.78rem;
  font-weight: 700;
}

.nav-track[open] {
  background: #fff;
  box-shadow: 0 8px 20px rgba(25, 37, 52, 0.05);
}

.nav-track-links {
  display: grid;
  gap: 4px;
  padding: 0 8px 8px;
}

.nav-item {
  display: grid;
  grid-template-columns: 28px 1fr;
  gap: 10px;
  align-items: center;
  min-height: 44px;
  padding: 9px 10px;
  border-radius: 8px;
  color: #263241;
  text-decoration: none;
  border: 1px solid transparent;
}

.nav-item:hover,
.nav-item.active {
  background: #eef4ff;
  border-color: #cfddff;
}

.nav-index {
  color: var(--blue-dark);
  font-weight: 800;
  font-size: 0.8rem;
  white-space: nowrap;
}

main {
  min-width: 0;
}

.topbar {
  position: sticky;
  top: 0;
  z-index: 4;
  display: grid;
  grid-template-columns: auto 1fr auto;
  gap: 16px;
  align-items: center;
  min-height: 86px;
  padding: 18px 34px;
  border-bottom: 1px solid var(--line);
  background: rgba(246, 248, 251, 0.92);
  backdrop-filter: blur(14px);
}

h1,
h2,
h3,
h4,
p {
  margin-top: 0;
}

.topbar h1 {
  margin-bottom: 0;
  font-size: clamp(1.35rem, 2vw, 2rem);
  line-height: 1.15;
}

.eyebrow {
  margin-bottom: 4px;
  font-weight: 800;
}

.icon-button,
.deploy-link,
.tab-button {
  border: 1px solid var(--line);
  background: #fff;
  color: var(--ink);
  border-radius: 8px;
  font: inherit;
  font-weight: 800;
  text-decoration: none;
}

.icon-button {
  display: none;
  width: 44px;
  height: 44px;
}

.deploy-link {
  padding: 10px 13px;
}

.content {
  width: min(1180px, calc(100% - 48px));
  margin: 0 auto;
  padding: 32px 0 56px;
}

.hero {
  display: grid;
  grid-template-columns: minmax(0, 1.25fr) minmax(300px, 0.75fr);
  gap: 24px;
  align-items: stretch;
  margin-bottom: 24px;
}

.hero-panel,
.panel,
.qa-card,
.comparison-card,
.callout {
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: 8px;
  box-shadow: var(--shadow);
}

.hero-panel {
  padding: clamp(24px, 4vw, 44px);
  background:
    linear-gradient(135deg, rgba(50, 108, 229, 0.95), rgba(15, 118, 110, 0.9)),
    url("https://images.unsplash.com/photo-1558494949-ef010cbdcc31?auto=format&fit=crop&w=1400&q=80");
  background-size: cover;
  background-position: center;
  color: #fff;
  min-height: 360px;
  display: grid;
  align-content: end;
}

.hero-panel h2 {
  font-size: clamp(2.2rem, 5vw, 4.8rem);
  line-height: 0.98;
  margin-bottom: 16px;
}

.hero-panel p {
  max-width: 760px;
  margin-bottom: 0;
  font-size: 1.1rem;
}

.stats-panel {
  padding: 22px;
  display: grid;
  gap: 14px;
}

.stat {
  padding: 16px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: #f9fbfd;
}

.stat strong {
  display: block;
  font-size: 1.65rem;
  color: var(--blue-dark);
}

.grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 16px;
}

.track-chip-row {
  display: flex;
  gap: 10px;
  flex-wrap: wrap;
  margin: 0 0 20px;
}

.track-chip {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  min-height: 40px;
  padding: 8px 12px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: #fff;
  color: #263241;
  text-decoration: none;
  font-weight: 800;
}

.track-chip span {
  display: inline-grid;
  place-items: center;
  min-width: 34px;
  min-height: 24px;
  border-radius: 6px;
  background: #eef4ff;
  color: var(--blue-dark);
  font-size: 0.75rem;
}

.track-chip:hover,
.track-chip.active {
  border-color: var(--blue);
  background: #eef4ff;
}

.learning-map-panel {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(260px, 360px);
  gap: 16px;
  align-items: end;
  margin: 0 0 20px;
  padding: 18px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: #fff;
  box-shadow: var(--shadow);
}

.learning-map-panel h3 {
  margin-bottom: 0;
}

.topic-picker {
  display: grid;
  gap: 7px;
}

.topic-picker span {
  color: var(--muted);
  font-size: 0.78rem;
  font-weight: 800;
  text-transform: uppercase;
}

.topic-picker select {
  width: 100%;
  min-height: 42px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: #f9fbfd;
  color: var(--ink);
  font: inherit;
  font-weight: 700;
  padding: 9px 12px;
}

.topic-picker select:focus {
  outline: 3px solid rgba(50, 108, 229, 0.16);
  border-color: var(--blue);
}

.panel {
  padding: 22px;
}

.panel h3,
.comparison-card h3,
.qa-card h4 {
  margin-bottom: 10px;
}

.topic-header {
  display: grid;
  gap: 14px;
  margin-bottom: 20px;
}

.topic-header h2 {
  font-size: clamp(2rem, 4vw, 3.6rem);
  line-height: 1.02;
  margin-bottom: 4px;
}

.summary {
  font-size: 1.08rem;
  color: #344154;
  max-width: 900px;
}

.meta-row,
.tag-row,
.tabs {
  display: flex;
  gap: 8px;
  flex-wrap: wrap;
  align-items: center;
}

.tag,
.meta-pill {
  display: inline-flex;
  align-items: center;
  min-height: 30px;
  padding: 5px 9px;
  border: 1px solid var(--line);
  border-radius: 999px;
  background: #fff;
  color: #354254;
  font-size: 0.84rem;
  font-weight: 700;
}

.tabs {
  margin: 20px 0;
}

.tab-button {
  padding: 9px 12px;
  cursor: pointer;
}

.tab-button.active {
  border-color: var(--blue);
  background: #eef4ff;
  color: var(--blue-dark);
}

.section-stack {
  display: grid;
  gap: 18px;
}

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

.definition-grid .panel strong {
  display: block;
  color: var(--blue-dark);
  margin-bottom: 8px;
}

.code-block {
  overflow-x: auto;
  border-radius: 8px;
  padding: 16px;
  background: #101820;
  color: #eaf2ff;
  font-family: "Cascadia Code", Consolas, monospace;
  font-size: 0.9rem;
}

.comparison-card {
  overflow: hidden;
}

.comparison-card h3 {
  padding: 18px 18px 0;
}

table {
  width: 100%;
  border-collapse: collapse;
}

th,
td {
  padding: 13px 16px;
  border-top: 1px solid var(--line);
  text-align: left;
  vertical-align: top;
}

th {
  background: #f1f5f9;
  color: #263241;
}

.qa-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(310px, 1fr));
  gap: 14px;
}

.qa-card {
  padding: 18px;
}

.qa-card span {
  display: inline-block;
  margin-bottom: 8px;
  color: var(--teal);
  font-size: 0.8rem;
  font-weight: 900;
  text-transform: uppercase;
}

.callout {
  padding: 18px;
  border-left: 5px solid var(--blue);
  box-shadow: none;
}

.warning {
  border-left-color: var(--gold);
}

.danger {
  border-left-color: var(--red);
}

.success {
  border-left-color: var(--green);
}

.search-results {
  display: grid;
  gap: 12px;
}

.result-card {
  display: block;
  padding: 16px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: #fff;
  text-decoration: none;
}

.result-card:hover {
  border-color: var(--blue);
}

.footer-note {
  margin-top: 28px;
  color: var(--muted);
  font-size: 0.95rem;
}

@media (max-width: 920px) {
  .app-shell {
    grid-template-columns: 1fr;
  }

  .sidebar {
    position: fixed;
    transform: translateX(-105%);
    transition: transform 180ms ease;
    width: min(330px, 88vw);
  }

  body.nav-open .sidebar {
    transform: translateX(0);
  }

  .icon-button {
    display: inline-grid;
    place-items: center;
  }

  .topbar {
    padding: 14px 18px;
  }

  .content {
    width: min(100% - 28px, 1180px);
    padding-top: 22px;
  }

  .hero,
  .definition-grid,
  .learning-map-panel {
    grid-template-columns: 1fr;
  }

  .deploy-link {
    display: none;
  }
}

@media (max-width: 580px) {
  .topbar {
    grid-template-columns: auto 1fr;
  }

  .hero-panel {
    min-height: 330px;
  }

  th,
  td {
    padding: 11px 12px;
  }
}