/* Yaaddi Courses — static site styles.
   System fonts only, no external requests. Light/dark via prefers-color-scheme. */

:root {
  --bg: #faf9f7;
  --bg-elevated: #ffffff;
  --text: #1c1a17;
  --text-muted: #6b6459;
  --border: #e7e2da;
  --accent: #2f6b4f;
  --accent-soft: #e5f0ea;
  --shadow: 0 1px 2px rgba(28, 26, 23, 0.04), 0 4px 16px rgba(28, 26, 23, 0.06);
  --radius: 14px;
  --font: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  --font-mono: ui-monospace, SFMono-Regular, "SF Mono", Consolas, "Liberation Mono", monospace;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #17150f;
    --bg-elevated: #201d17;
    --text: #f1ede4;
    --text-muted: #a89f8f;
    --border: #332e24;
    --accent: #6bc79a;
    --accent-soft: #1f2e26;
    --shadow: 0 1px 2px rgba(0, 0, 0, 0.3), 0 4px 20px rgba(0, 0, 0, 0.35);
  }
}

* { box-sizing: border-box; }

body {
  margin: 0;
  font-family: var(--font);
  background: var(--bg);
  color: var(--text);
  line-height: 1.5;
}

img { max-width: 100%; display: block; }

.site-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 10px 22px;
  padding: 18px 32px;
  border-bottom: 1px solid var(--border);
  position: sticky;
  top: 0;
  background: var(--bg);
  z-index: 10;
}
.brand {
  font-weight: 700;
  font-size: 1.05rem;
  color: var(--text);
  text-decoration: none;
  letter-spacing: -0.01em;
}
.header-nav { display: flex; align-items: center; gap: 22px; }
.header-link {
  color: var(--text-muted);
  text-decoration: none;
  font-size: 0.9rem;
}
.header-link:hover { color: var(--accent); }

.hero {
  max-width: 900px;
  margin: 56px auto 32px;
  padding: 0 24px;
  text-align: center;
}
.hero h1 {
  font-size: 2.4rem;
  margin: 0 0 12px;
  letter-spacing: -0.02em;
}
.tagline {
  color: var(--text-muted);
  font-size: 1.05rem;
  margin: 0 0 28px;
}

.search-row { display: flex; justify-content: center; margin-bottom: 18px; }
#search {
  width: 100%;
  max-width: 420px;
  padding: 11px 16px;
  border-radius: 999px;
  border: 1px solid var(--border);
  background: var(--bg-elevated);
  color: var(--text);
  font-size: 0.95rem;
}
#search:focus { outline: 2px solid var(--accent); outline-offset: 1px; }

.tag-filter-row {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  justify-content: center;
}
.tag-filter {
  border: 1px solid var(--border);
  background: var(--bg-elevated);
  color: var(--text-muted);
  border-radius: 999px;
  padding: 6px 14px;
  font-size: 0.85rem;
  cursor: pointer;
}
.tag-filter.active,
.tag-filter:hover {
  border-color: var(--accent);
  color: var(--accent);
  background: var(--accent-soft);
}

.course-grid {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 24px 64px;
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 22px;
}

.course-card {
  display: block;
  background: var(--bg-elevated);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  overflow: hidden;
  text-decoration: none;
  color: inherit;
  box-shadow: var(--shadow);
  transition: transform 0.15s ease, box-shadow 0.15s ease;
}
.course-card:hover {
  transform: translateY(-2px);
  box-shadow: 0 2px 4px rgba(0,0,0,0.06), 0 10px 28px rgba(0,0,0,0.1);
}
.cover {
  width: 100%;
  aspect-ratio: 2.4 / 1;
  object-fit: cover;
  background: var(--accent-soft);
}
.cover-empty { background: linear-gradient(135deg, var(--accent-soft), var(--border)); }

.course-card-body { padding: 18px 20px 20px; }
.course-card-body h3 { margin: 0 0 8px; font-size: 1.1rem; letter-spacing: -0.01em; }
.course-desc {
  color: var(--text-muted);
  font-size: 0.9rem;
  margin: 0 0 14px;
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

.tag-row { display: flex; flex-wrap: wrap; gap: 6px; margin-bottom: 12px; }
.chip {
  font-size: 0.72rem;
  color: var(--accent);
  background: var(--accent-soft);
  padding: 3px 9px;
  border-radius: 999px;
  font-weight: 600;
  letter-spacing: 0.01em;
}

.course-stats {
  display: flex;
  gap: 8px;
  color: var(--text-muted);
  font-size: 0.82rem;
  font-variant-numeric: tabular-nums;
}

.no-results {
  text-align: center;
  color: var(--text-muted);
  padding: 40px 0;
}

/* Course detail page */
.course-main { max-width: 900px; margin: 0 auto; padding: 32px 24px 64px; }
.back-link {
  color: var(--text-muted);
  text-decoration: none;
  font-size: 0.9rem;
  display: inline-block;
  margin-bottom: 24px;
}
.back-link:hover { color: var(--accent); }

.course-hero {
  display: grid;
  grid-template-columns: 320px 1fr;
  gap: 28px;
  align-items: start;
  margin-bottom: 40px;
}
@media (max-width: 720px) {
  .course-hero { grid-template-columns: 1fr; }
}
.cover-large {
  width: 100%;
  border-radius: var(--radius);
  aspect-ratio: 2.4 / 1;
  object-fit: cover;
  box-shadow: var(--shadow);
}
.course-hero-body h1 { font-size: 1.9rem; margin: 0 0 12px; letter-spacing: -0.02em; }
.course-desc-large { color: var(--text-muted); font-size: 1rem; margin: 0 0 16px; }

.course-stats-row { display: flex; gap: 28px; margin-top: 18px; flex-wrap: wrap; }
.stat { display: flex; flex-direction: column; }
.stat strong { font-size: 1.3rem; font-variant-numeric: tabular-nums; }
.stat span { color: var(--text-muted); font-size: 0.78rem; text-transform: uppercase; letter-spacing: 0.04em; }

.section { margin-bottom: 40px; }
.section h2 { font-size: 1.15rem; margin: 0 0 16px; letter-spacing: -0.01em; }

/* Help / Contribute pages — same shell as the course detail page. */
.content-main { max-width: 720px; margin: 0 auto; padding: 32px 24px 64px; }
.content-main h1 { font-size: 1.9rem; margin: 0 0 12px; letter-spacing: -0.02em; }
.content-intro { color: var(--text-muted); font-size: 1rem; margin: 0 0 40px; }
.content-main .section p { margin: 0 0 12px; }
.content-main .section a { color: var(--accent); }
.help-steps { margin: 0; padding-left: 22px; }
.help-steps li { margin-bottom: 10px; }
.content-main code {
  font-family: var(--font-mono);
  font-size: 0.85em;
  background: var(--accent-soft);
  padding: 0.1em 0.4em;
  border-radius: 4px;
}

.type-bar {
  display: flex;
  height: 10px;
  border-radius: 999px;
  overflow: hidden;
  background: var(--border);
  margin-bottom: 12px;
}
.type-seg { height: 100%; background: var(--accent); }
.type-seg:nth-child(2n) { opacity: 0.75; }
.type-seg:nth-child(3n) { opacity: 0.55; }
.type-seg:nth-child(4n) { opacity: 0.9; }
.type-legend {
  list-style: none;
  padding: 0;
  margin: 0;
  display: flex;
  flex-wrap: wrap;
  gap: 6px 16px;
  color: var(--text-muted);
  font-size: 0.82rem;
}

.toc-list {
  columns: 2;
  column-gap: 32px;
  padding-left: 22px;
  color: var(--text);
  font-size: 0.92rem;
}
.toc-list li { margin-bottom: 8px; break-inside: avoid; }
@media (max-width: 600px) { .toc-list { columns: 1; } }

.examples { display: grid; gap: 14px; }
.card-preview {
  background: var(--bg-elevated);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 18px 20px;
}
.card-type-badge {
  font-size: 0.7rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--accent);
}
.card-prompt { margin: 10px 0 0; font-size: 1rem; }
.preview-options {
  list-style: none;
  padding: 0;
  margin: 12px 0 0;
  display: grid;
  gap: 6px;
}
.preview-options li {
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 8px 12px;
  font-size: 0.88rem;
  font-family: var(--font-mono);
}

.changelog-note { color: var(--text-muted); font-size: 0.88rem; font-style: italic; }

.site-footer {
  border-top: 1px solid var(--border);
  padding: 28px 24px;
  text-align: center;
  color: var(--text-muted);
  font-size: 0.85rem;
}
.site-footer a { color: var(--accent); }
.footer-credit {
  margin-top: 8px;
  font-size: 0.8rem;
  opacity: 0.85;
}