/* Sigma Speaks site. One stylesheet, no framework, no build step for the hand-written pages.
   Colours follow the apps: BrandPrimary #0056B3 and the Σ artwork. */

:root {
  --brand: #0056B3;
  --brand-ink: #003f85;
  --accent: #1E88E5;
  --bg: #f4f5f7;
  --surface: #ffffff;
  --surface-2: #e9e9ea;
  --text: #16181d;
  --muted: #5b616b;
  --line: #d9dce1;
  --ok: #1b7f3b;
  --max: 1040px;
  --radius: 14px;
  --shadow: 0 8px 28px rgba(16, 24, 40, 0.08);
}

@media (prefers-color-scheme: dark) {
  :root {
    --brand: #4d9bff;
    --brand-ink: #9cc5ff;
    --accent: #6fb3ff;
    --bg: #0f1216;
    --surface: #181c22;
    --surface-2: #232931;
    --text: #e8eaee;
    --muted: #a0a7b1;
    --line: #2d343d;
    --shadow: 0 8px 28px rgba(0, 0, 0, 0.4);
  }
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  font: 17px/1.55 -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  color: var(--text);
  background: var(--bg);
  -webkit-font-smoothing: antialiased;
}
a { color: var(--brand); text-decoration: none; }
a:hover { text-decoration: underline; }
img { max-width: 100%; height: auto; }
h1, h2, h3 { line-height: 1.15; margin: 0 0 0.5em; letter-spacing: -0.01em; }
h1 { font-size: clamp(2rem, 5vw, 3rem); }
h2 { font-size: clamp(1.5rem, 3.2vw, 2rem); }
h3 { font-size: 1.15rem; }
p { margin: 0 0 1em; }
.container { max-width: var(--max); margin: 0 auto; padding: 0 20px; }
.muted { color: var(--muted); }
.small { font-size: 0.9rem; }

/* Header */
.site-header { position: sticky; top: 0; z-index: 10; background: color-mix(in srgb, var(--bg) 88%, transparent); backdrop-filter: saturate(160%) blur(10px); border-bottom: 1px solid var(--line); }
.nav { display: flex; align-items: center; justify-content: space-between; height: 60px; gap: 16px; }
.nav-logo { display: inline-flex; align-items: center; gap: 10px; font-weight: 700; color: var(--text); font-size: 1.05rem; }
.nav-logo img { width: 28px; height: 28px; border-radius: 6px; }
.nav-links { display: flex; align-items: center; gap: 22px; }
.nav-links a { color: var(--text); font-weight: 500; }
.nav-links a.cta { background: var(--brand); color: #fff; padding: 8px 14px; border-radius: 999px; }
.nav-links a.cta:hover { text-decoration: none; background: var(--brand-ink); }
.nav-toggle { display: none; background: none; border: 0; padding: 8px; cursor: pointer; }
.nav-toggle span { display: block; width: 22px; height: 2px; background: var(--text); margin: 4px 0; }
@media (max-width: 720px) {
  .nav-toggle { display: block; }
  .nav-links { display: none; position: absolute; left: 0; right: 0; top: 60px; flex-direction: column; align-items: stretch; background: var(--surface); border-bottom: 1px solid var(--line); padding: 12px 20px 18px; gap: 14px; }
  .nav-links.open { display: flex; }
  .nav-links a.cta { text-align: center; }
}

/* Hero */
.hero { padding: 64px 0 36px; }
.hero-grid { display: grid; grid-template-columns: 1.3fr 0.7fr; gap: 40px; align-items: center; }
@media (max-width: 820px) { .hero-grid { grid-template-columns: 1fr; } .hero-art { order: -1; max-width: 220px; margin: 0 auto; } }
.hero p.lead { font-size: 1.2rem; color: var(--muted); max-width: 560px; }
.hero-art img { border-radius: 24px; box-shadow: var(--shadow); }
.hero-badge { display: inline-block; font-size: 0.85rem; font-weight: 600; color: var(--brand); background: color-mix(in srgb, var(--brand) 12%, transparent); padding: 4px 12px; border-radius: 999px; margin-bottom: 14px; }
.actions { display: flex; flex-wrap: wrap; gap: 12px; margin-top: 18px; }
.btn { display: inline-flex; align-items: center; gap: 8px; padding: 12px 20px; border-radius: 999px; font-weight: 600; border: 1px solid var(--line); background: var(--surface); color: var(--text); cursor: pointer; font-size: 1rem; }
.btn:hover { text-decoration: none; border-color: var(--brand); }
.btn.primary { background: var(--brand); border-color: var(--brand); color: #fff; }
.btn.primary:hover { background: var(--brand-ink); border-color: var(--brand-ink); }
.btn[hidden] { display: none; }

/* Sections */
section { padding: 44px 0; }
section.alt { background: var(--surface); border-top: 1px solid var(--line); border-bottom: 1px solid var(--line); }
.grid-3 { display: grid; grid-template-columns: repeat(3, 1fr); gap: 24px; }
@media (max-width: 820px) { .grid-3 { grid-template-columns: 1fr; } }
.card { background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius); padding: 22px; }
section.alt .card { background: var(--bg); }
.card h3 { margin-top: 0; }
.eyebrow { text-transform: uppercase; letter-spacing: 0.08em; font-size: 0.78rem; font-weight: 700; color: var(--muted); margin-bottom: 8px; }

/* Episode player */
.episode { background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius); box-shadow: var(--shadow); padding: 22px; }
.episode-head { display: flex; justify-content: space-between; gap: 12px; flex-wrap: wrap; align-items: baseline; }
.episode-head h3 { font-size: 1.3rem; margin: 0; }
.episode audio { width: 100%; margin: 14px 0 6px; }
.chapters { list-style: none; margin: 10px 0 0; padding: 0; display: grid; grid-template-columns: 1fr 1fr; gap: 2px 18px; }
@media (max-width: 720px) { .chapters { grid-template-columns: 1fr; } }
.chapters li { display: flex; gap: 10px; align-items: baseline; }
.chapters button { background: none; border: 0; padding: 6px 0; text-align: left; color: var(--text); cursor: pointer; font: inherit; display: flex; gap: 10px; align-items: baseline; width: 100%; }
.chapters button:hover { color: var(--brand); }
.chapters button.current { color: var(--brand); font-weight: 600; }
.chapters time { font-variant-numeric: tabular-nums; color: var(--muted); font-size: 0.9rem; min-width: 44px; }
.episode-foot { display: flex; flex-wrap: wrap; gap: 14px; margin-top: 14px; font-size: 0.95rem; }
.transcript { margin-top: 14px; }
.transcript summary { cursor: pointer; font-weight: 600; }
.transcript p { margin: 0.6em 0; }
.notes ul { padding-left: 20px; }
.notes li { margin: 4px 0; }

/* Subscribe row */
.subscribe { display: flex; flex-wrap: wrap; gap: 12px; align-items: center; }
.feed-url { display: inline-flex; align-items: center; gap: 8px; background: var(--surface-2); border-radius: 999px; padding: 8px 14px; font-family: ui-monospace, SFMono-Regular, Menlo, monospace; font-size: 0.85rem; max-width: 100%; overflow: hidden; }
.feed-url button { border: 0; background: var(--brand); color: #fff; border-radius: 999px; padding: 4px 10px; cursor: pointer; font: inherit; }

/* App badges */
.badges { display: flex; flex-wrap: wrap; gap: 12px; align-items: center; }
.badge { display: inline-flex; align-items: center; gap: 10px; border: 1px solid var(--line); border-radius: 10px; padding: 10px 16px; background: var(--surface); color: var(--text); font-weight: 600; }
.badge:hover { text-decoration: none; border-color: var(--brand); }
.badge small { display: block; font-weight: 400; color: var(--muted); font-size: 0.75rem; }
.screens { display: grid; grid-template-columns: 1fr 1fr; gap: 16px; }
@media (max-width: 720px) { .screens { grid-template-columns: 1fr; } }

/* Archive */
.episode-list { list-style: none; padding: 0; margin: 0; }
.episode-list li { padding: 16px 0; border-bottom: 1px solid var(--line); display: grid; grid-template-columns: 110px 1fr auto; gap: 14px; align-items: baseline; }
@media (max-width: 720px) { .episode-list li { grid-template-columns: 1fr; gap: 4px; } }
.episode-list time { color: var(--muted); font-variant-numeric: tabular-nums; }
.episode-list .dur { color: var(--muted); font-size: 0.9rem; }

/* Prose pages */
.prose { max-width: 760px; }
.prose h1 { margin-bottom: 0.3em; }
.prose h2 { font-size: 1.3rem; margin-top: 1.8em; }
.prose ul { padding-left: 22px; }
.prose li { margin: 6px 0; }
.prose .updated { color: var(--muted); font-size: 0.9rem; margin-bottom: 2em; }

/* Footer */
.site-footer { border-top: 1px solid var(--line); padding: 28px 0 40px; color: var(--muted); font-size: 0.92rem; }
.site-footer .row { display: flex; flex-wrap: wrap; gap: 8px 22px; justify-content: space-between; align-items: center; }
.site-footer nav { display: flex; flex-wrap: wrap; gap: 18px; }
.site-footer nav a { color: var(--muted); }
.disclaimer { margin-top: 12px; }