:root {
  color-scheme: dark;
  --bg: #050505;
  --panel: #101413;
  --panel-soft: #171d1b;
  --text: #f4f1e8;
  --muted: #b8c0b9;
  --line: #2b3430;
  --accent: #ffb31a;
  --accent-strong: #ff7a1a;
  --blue: #72c8ff;
}

* {
  box-sizing: border-box;
}

html {
  min-height: 100%;
  background: var(--bg);
}

body {
  min-height: 100%;
  margin: 0;
  background:
    radial-gradient(circle at 18% 0%, rgba(255, 179, 26, 0.14), transparent 32rem),
    linear-gradient(135deg, #050505 0%, #0d1210 54%, #111713 100%);
  color: var(--text);
  font-family:
    Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  line-height: 1.55;
}

a {
  color: var(--blue);
  text-decoration: none;
}

a:hover {
  text-decoration: underline;
}

.page {
  width: min(900px, calc(100% - 32px));
  margin: 0 auto;
  padding: 42px 0 56px;
}

.topbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 18px;
  margin-bottom: 56px;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  color: var(--text);
  font-weight: 800;
  letter-spacing: 0;
}

.brand img {
  width: 36px;
  height: 36px;
}

.nav {
  display: flex;
  flex-wrap: wrap;
  gap: 16px;
  color: var(--muted);
  font-size: 0.95rem;
}

.hero {
  margin-bottom: 38px;
}

.eyebrow {
  margin: 0 0 12px;
  color: var(--accent);
  font-size: 0.78rem;
  font-weight: 800;
  letter-spacing: 0.12em;
  text-transform: uppercase;
}

h1 {
  max-width: 760px;
  margin: 0;
  font-size: clamp(2.2rem, 7vw, 4.7rem);
  line-height: 0.95;
  letter-spacing: 0;
}

.lead {
  max-width: 720px;
  margin: 20px 0 0;
  color: var(--muted);
  font-size: 1.18rem;
}

.section {
  padding: 26px 0;
  border-top: 1px solid var(--line);
}

h2 {
  margin: 0 0 12px;
  font-size: 1.25rem;
  letter-spacing: 0;
}

p,
ul,
ol {
  margin: 0 0 14px;
}

ul {
  padding-left: 1.3rem;
}

.lesson-grid,
.drill-list {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 14px;
}

.lesson-card,
.drill-list article {
  min-height: 180px;
  padding: 18px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: color-mix(in srgb, var(--panel) 88%, transparent);
}

.lesson-card {
  display: block;
  color: var(--text);
}

.lesson-card:hover {
  border-color: color-mix(in srgb, var(--accent) 52%, var(--line));
  text-decoration: none;
}

.lesson-card span,
.drill-list span {
  display: inline-block;
  margin-bottom: 14px;
  color: var(--accent);
  font-family:
    ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, "Liberation Mono", monospace;
  font-size: 0.76rem;
  font-weight: 800;
}

.lesson-card h3,
.drill-list h3 {
  margin: 0 0 8px;
  font-size: 1.05rem;
}

.lesson-card p,
.drill-list p {
  margin: 0;
  color: var(--muted);
}

.lesson-nav {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-top: 24px;
}

.lesson-nav a {
  display: inline-flex;
  align-items: center;
  min-height: 36px;
  padding: 0 12px;
  border: 1px solid var(--line);
  border-radius: 999px;
  background: color-mix(in srgb, var(--panel-soft) 82%, transparent);
  color: var(--text);
  font-size: 0.9rem;
  font-weight: 700;
}

.lesson-nav a:hover {
  border-color: color-mix(in srgb, var(--accent) 52%, var(--line));
  text-decoration: none;
}

.lesson-article .section:last-child {
  padding-bottom: 34px;
}

.term-list {
  display: grid;
  gap: 12px;
  margin: 0;
}

.term-list div {
  padding: 16px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: color-mix(in srgb, var(--panel) 88%, transparent);
}

.term-list dt {
  margin-bottom: 4px;
  color: var(--text);
  font-weight: 800;
}

.term-list dd {
  margin: 0;
  color: var(--muted);
}

.faq-list details {
  padding: 16px 0;
  border-top: 1px solid var(--line);
}

.faq-list details:first-of-type {
  margin-top: 8px;
}

.faq-list summary {
  cursor: pointer;
  color: var(--text);
  font-weight: 800;
}

.faq-list details p {
  margin-top: 10px;
  margin-bottom: 0;
  color: var(--muted);
}

.support-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 14px;
}

.support-grid--two {
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
}

.comparison-table {
  display: table;
  width: 100%;
  border-collapse: collapse;
  margin: 10px 0 18px;
  overflow-x: auto;
  border: 1px solid var(--line);
  border-radius: 8px;
}

.comparison-table th,
.comparison-table td {
  padding: 12px;
  border-bottom: 1px solid var(--line);
  text-align: left;
  vertical-align: top;
}

.comparison-table th {
  color: var(--text);
  background: color-mix(in srgb, var(--panel-soft) 90%, transparent);
  font-size: 0.88rem;
}

.comparison-table td {
  color: var(--muted);
}

.comparison-table tr:last-child td {
  border-bottom: 0;
}

.docs-table td:first-child,
.docs-table th:first-child {
  min-width: 150px;
}

.formula-block {
  margin: 18px 0;
  padding: 16px;
  overflow-x: auto;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: color-mix(in srgb, var(--panel-soft) 86%, transparent);
  color: var(--text);
  font-family:
    ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, "Liberation Mono", monospace;
  font-size: 0.9rem;
  line-height: 1.5;
}

.formula-block code {
  font: inherit;
}

.source-list {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  padding: 0;
  list-style: none;
}

.source-list a {
  display: inline-flex;
  align-items: center;
  min-height: 34px;
  padding: 0 10px;
  border: 1px solid var(--line);
  border-radius: 8px;
  color: var(--text);
  font-size: 0.88rem;
  font-weight: 700;
}

.source-list a:hover {
  border-color: color-mix(in srgb, var(--accent) 52%, var(--line));
  text-decoration: none;
}

@media (max-width: 700px) {
  .comparison-table {
    display: block;
  }

  .comparison-table th,
  .comparison-table td {
    min-width: 150px;
  }
}

.support-card {
  padding: 18px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: color-mix(in srgb, var(--panel) 88%, transparent);
}

.support-card h3 {
  margin: 0 0 10px;
  font-size: 1rem;
}

.support-card p,
.support-card ul {
  margin-bottom: 0;
  color: var(--muted);
}

.split-section {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(220px, 0.42fr);
  gap: 24px;
  align-items: start;
}

.check-list {
  margin: 0;
  padding-left: 1.4rem;
}

.check-list li {
  margin-bottom: 8px;
}

.support-note {
  padding: 18px;
  border: 1px solid #624810;
  border-radius: 8px;
  background: color-mix(in srgb, var(--accent) 14%, var(--panel));
  color: var(--muted);
}

.support-note strong {
  display: block;
  margin-bottom: 8px;
  color: var(--text);
}

.contact-list {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 12px;
  padding: 0;
  list-style: none;
}

.contact-list li {
  min-height: 84px;
  padding: 16px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: color-mix(in srgb, var(--panel) 86%, transparent);
}

.contact-list strong {
  display: block;
  margin-bottom: 4px;
}

.button-row {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 24px;
}

.button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 44px;
  padding: 0 16px;
  border: 1px solid #624810;
  border-radius: 8px;
  background: linear-gradient(180deg, var(--accent), var(--accent-strong));
  color: #160f00;
  font-weight: 800;
}

.button.secondary {
  border-color: var(--line);
  background: var(--panel-soft);
  color: var(--text);
}

.footer {
  padding-top: 28px;
  border-top: 1px solid var(--line);
  color: var(--muted);
  font-size: 0.92rem;
}

@media (max-width: 620px) {
  .topbar {
    align-items: flex-start;
    flex-direction: column;
    margin-bottom: 42px;
  }

  .page {
    width: min(100% - 24px, 900px);
    padding-top: 28px;
  }

  .split-section {
    grid-template-columns: 1fr;
  }
}