/* Shared site theme: Mountain Winter.
   Pale cool paper, ink-slate serif type, an icy slate-blue accent,
   frosty cards, and a watercolor mountain range (assets/winter-range.jpg)
   behind a centered hero. */

:root {
  --bg: #f6f8fa;
  --card: #fcfdfe;
  --ink: #0f1a26;
  --body: #22324a;
  --muted: #4f5f73;
  --accent: #1f4f75;
  --accent-deep: #163a58;
  --line: #d6e1ea;
  --line-strong: #c3d2de;
  --good: #2f6f5e;
  --shadow: 0 1px 6px rgba(15, 40, 70, 0.06);
  --radius: 6px;
  --font: Georgia, "Iowan Old Style", "Palatino Linotype", "DejaVu Serif", serif;
  --sans: "Helvetica Neue", "Segoe UI", "DejaVu Sans", Arial, sans-serif;
  --glow: 0 0 18px var(--bg), 0 0 8px var(--bg);
  /* Names the Nestor page already uses. */
  --paper: var(--bg);
  --copper: var(--accent);
  --header: var(--ink);
  --header-2: var(--accent-deep);
  --navy: var(--ink);
  --blue: var(--accent);
}

* { box-sizing: border-box; }
html, body { margin: 0; padding: 0; }

body {
  background: var(--bg);
  color: var(--ink);
  font-family: var(--font);
  font-size: 16px;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

h1, h2, h3 { font-family: var(--font); font-weight: normal; letter-spacing: 0; line-height: 1.15; color: var(--ink); }

a { color: var(--accent); }
a:hover { color: var(--accent-deep); }

/* Header: italic serif wordmark, small-caps sans nav, ink rule. */
.site-header { position: relative; z-index: 2; background: var(--bg); color: var(--ink); }
.site-topbar-inner, .site-bar-inner, .page, .site-footer-inner {
  max-width: 1120px; margin: 0 auto; padding-left: 24px; padding-right: 24px;
}
.site-topbar { display: none; }
.site-bar-inner {
  display: flex; align-items: center; justify-content: space-between; gap: 16px;
  padding-top: 26px; padding-bottom: 14px; border-bottom: 1.5px solid var(--ink);
}
.site-name { color: var(--ink); font-style: italic; font-size: 30px; text-decoration: none; }
.site-name:hover { color: var(--accent); }
.site-nav, .site-count { font-family: var(--sans); font-size: 13px; letter-spacing: .14em; text-transform: uppercase; }
.site-nav { display: flex; gap: 30px; }
.site-nav a { color: var(--ink); text-decoration: none; }
.site-nav a:hover { color: var(--accent); }
.site-count { color: var(--muted); }
.site-bar-right { display: flex; align-items: center; gap: 30px; }

/* Landing hero: centered over the watercolor range. */
.hero {
  position: relative; isolation: isolate; background: var(--bg); text-align: center; padding: 56px 24px 64px; overflow: hidden;
  max-width: 1280px; margin: 0 auto;
}
.hero::before {
  content: ""; position: absolute; inset: 0;
  background: url("winter-range.jpg") center 62% / 1280px auto no-repeat;
  opacity: .6;
  mix-blend-mode: multiply;
  -webkit-mask-image: linear-gradient(#000 70%, transparent 100%);
          mask-image: linear-gradient(#000 70%, transparent 100%);
}
.hero::after {
  content: ""; position: absolute; left: 50%; top: 20px; width: 720px; height: 280px; transform: translateX(-50%);
  background: radial-gradient(ellipse at center, rgba(246,248,250,.88) 42%, rgba(246,248,250,0) 72%);
}
.hero > * { position: relative; z-index: 1; }
.kicker { color: var(--accent); font-family: var(--sans); font-size: 12px; letter-spacing: .22em; text-transform: uppercase; }
.hero h1 { font-size: clamp(2.2rem, 1.2rem + 2.6vw, 2.9rem); margin: 18px auto 14px; max-width: 640px; text-shadow: var(--glow); }
.hero .lede { margin: 0 auto; text-shadow: 0 0 10px var(--bg); }

.page { padding-top: 36px; padding-bottom: 56px; }
.page h1 { margin: 0 0 12px; font-size: clamp(2rem, 1rem + 2.4vw, 2.75rem); }
.lede { margin: 0; max-width: 60ch; color: var(--body); font-size: 18px; }

.demo-list {
  list-style: none; margin: 0; padding: 32px 0 0; border-top: 1px solid var(--line);
  display: grid; grid-template-columns: repeat(auto-fit, minmax(280px, 1fr)); gap: 32px;
}
.demo-list:has(> li:only-child) { grid-template-columns: minmax(280px, 420px); justify-content: center; }
.demo-card {
  display: flex; flex-direction: column; height: 100%; text-align: center;
  background: var(--card); border: 1px solid var(--line); border-radius: var(--radius);
  padding: 22px 24px; text-decoration: none; color: inherit; box-shadow: var(--shadow);
}
.demo-card:hover { border-color: var(--accent); }
.demo-card:focus-visible { outline: 2px solid var(--accent); outline-offset: 3px; }
.demo-card time { display: block; margin-bottom: 8px; color: var(--muted); font-family: var(--sans); font-size: 13px; }
.demo-card h2 { margin: 0 0 10px; font-size: 1.6rem; }
.demo-card p { margin: 0 0 18px; color: var(--body); font-size: 17px; }
.demo-card-path { margin-top: auto; align-self: center; color: var(--accent); border-bottom: 1px solid var(--accent); font-size: 16px; }

.empty { color: var(--muted); text-align: center; }

.site-footer { color: var(--muted); font-family: var(--sans); font-size: 12px; letter-spacing: .08em; }
.site-footer-inner { padding-top: 16px; padding-bottom: 28px; text-align: center; }
.site-footer-inner > * { border-top: 1px solid var(--line); }
.site-footer-inner > * + * { border-top: 0; }
.site-footer p { margin: 0; padding-top: 10px; }
.site-footer a { color: var(--accent); }
.site-footer code { font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace; font-size: .95em; letter-spacing: 0; }

/* Demo pages: the "Inspired by" list near the bottom of index.html. */
.sources {
  margin: 28px 0 4px;
  padding-top: 16px;
  border-top: 1px solid var(--line);
  color: var(--body);
  font-family: var(--sans);
  font-size: 14px;
  line-height: 1.5;
}
.sources h2 {
  margin: 0 0 8px;
  font-family: var(--sans);
  font-size: 12px;
  font-weight: 600;
  letter-spacing: .16em;
  text-transform: uppercase;
  color: var(--muted);
  line-height: 1.3;
}
.sources ul { margin: 0; padding-left: 1.2em; }
.sources li { margin: 3px 0; }
.sources a { color: var(--accent); }

/* Demo pages: a subtle strip of the range under the site header. */
.site-header.demo-header::after {
  content: ""; display: block; height: 90px; margin-top: -1px;
  background: url("winter-range.jpg") center 58% / 1280px auto no-repeat;
  opacity: .35;
  mix-blend-mode: multiply;
  -webkit-mask-image: linear-gradient(transparent, #000 30%, #000 50%, transparent);
          mask-image: linear-gradient(transparent, #000 30%, #000 50%, transparent);
}

/* Shared controls. Scoped so diagram buttons inside a demo can opt out. */
.btn, .presets button, .schedule button, .layer-tabs button, #reshuffle {
  border: 1px solid var(--accent); background: var(--card); color: var(--accent);
  border-radius: 6px; padding: 8px 14px; font-family: var(--sans); font-size: 13px;
  letter-spacing: .3px; line-height: 1.2; cursor: pointer;
}
.btn:hover, .presets button:hover, .schedule button:hover, .layer-tabs button:hover, #reshuffle:hover,
.presets button[aria-pressed="true"], .schedule button[aria-pressed="true"], .layer-tabs button[aria-pressed="true"] {
  background: var(--accent); border-color: var(--accent); color: #fff;
}
input[type="range"] { accent-color: var(--accent); width: 100%; }
input[type="number"], input[type="text"], input[type="search"] {
  font-family: var(--sans); border: 1px solid var(--line-strong); border-radius: 6px; background: #fff; color: var(--ink);
}
:focus-visible { outline: 2px solid var(--accent); outline-offset: 2px; }

@media (max-width: 640px) {
  .site-name { font-size: 24px; }
  .hero { padding: 36px 16px 44px; }
  .page { padding-top: 24px; }
}