:root {
  --bg: #05070c;
  --ink: #e8eef8;
  --muted: #8b98ad;
  --dim: #5a6577;
  --line: rgba(121, 231, 255, 0.14);
  --cyan: #79e7ff;
  --amber: #ffb15a;
  --chosen: #ff7a3c;
  --mono: "Cascadia Code", "JetBrains Mono", Consolas, "Courier New", monospace;
  --sans: "Segoe UI", "PingFang SC", "Noto Sans SC", "Microsoft YaHei", sans-serif;
  --mx: 50vw;
  --my: 30vh;
  color-scheme: dark;
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  min-height: 100vh;
  color: var(--ink);
  background: var(--bg);
  font-family: var(--sans);
  font-size: 1.05rem;
  line-height: 1.75;
  overflow-x: hidden;
}

/* full-screen particle field */
.fx-particles {
  position: fixed;
  inset: 0;
  width: 100%;
  height: 100%;
  z-index: 0;
  pointer-events: none;
}

/* pointer glow above particles, below content */
body::before {
  content: "";
  position: fixed;
  inset: 0;
  z-index: 1;
  pointer-events: none;
  background:
    radial-gradient(640px circle at var(--mx) var(--my), rgba(121, 231, 255, 0.10), transparent 55%),
    radial-gradient(1200px circle at 85% -10%, rgba(255, 122, 60, 0.07), transparent 50%);
}

/* faint scanline grid */
body::after {
  content: "";
  position: fixed;
  inset: 0;
  z-index: 1;
  pointer-events: none;
  background-image:
    linear-gradient(rgba(121, 231, 255, 0.035) 1px, transparent 1px),
    linear-gradient(90deg, rgba(121, 231, 255, 0.035) 1px, transparent 1px);
  background-size: 96px 96px;
  mask-image: radial-gradient(ellipse at 50% 25%, black 0%, transparent 78%);
}

header.site, main, footer.site { position: relative; z-index: 2; }

a { color: var(--cyan); text-decoration: none; text-underline-offset: 0.2em; }
a:hover { color: #fff; text-shadow: 0 0 12px rgba(121, 231, 255, 0.6); }

.wrap { width: min(76rem, calc(100% - 3rem)); margin: 0 auto; }

/* ---------- header: borderless floating bar ---------- */
header.site {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 10;
  padding: 1.1rem 0;
  background: linear-gradient(180deg, rgba(5, 7, 12, 0.85), transparent);
  backdrop-filter: blur(6px);
  -webkit-backdrop-filter: blur(6px);
}

.bar { display: flex; align-items: center; justify-content: space-between; gap: 1rem; }

.brand {
  font-family: var(--mono);
  font-size: 0.95rem;
  letter-spacing: 0.14em;
  color: var(--ink);
}
.brand strong { color: #fff; font-weight: 700; }
.brand span { color: var(--amber); }

.nav-group { display: flex; align-items: center; gap: 1.6rem; }

header.site nav { display: flex; gap: 1.4rem; }
header.site nav a {
  font-family: var(--mono);
  font-size: 0.82rem;
  letter-spacing: 0.1em;
  color: var(--muted);
  transition: color 0.2s, text-shadow 0.2s;
}
header.site nav a:hover { color: var(--cyan); text-shadow: 0 0 10px rgba(121, 231, 255, 0.7); }
header.site nav a[aria-current="page"] { color: var(--cyan); }

.langs { border-left: 1px solid var(--line); padding-left: 1.4rem; }
.langs a { padding: 0.15rem 0.45rem; }
.langs a[aria-current="true"] {
  color: var(--bg);
  background: var(--cyan);
  text-shadow: none;
}

/* ---------- home stage: full viewport, no frame ---------- */
.stage {
  min-height: 100vh;
  display: grid;
  grid-template-columns: 1.15fr 1fr;
  align-items: center;
  gap: 3rem;
  padding-top: 4rem;
}

canvas[data-fork] {
  width: 100%;
  height: min(72vh, 640px);
  display: block;
}

.stage-copy .kicker {
  font-family: var(--mono);
  font-size: 0.78rem;
  letter-spacing: 0.32em;
  text-transform: uppercase;
  color: var(--cyan);
  margin: 0 0 1.2rem;
}
.stage-copy .kicker::before { content: "∵ "; color: var(--amber); }

h1 {
  font-size: clamp(2.6rem, 6vw, 4.6rem);
  line-height: 1.08;
  margin: 0 0 1.4rem;
  font-weight: 700;
  letter-spacing: -0.01em;
  text-shadow: 0 0 40px rgba(121, 231, 255, 0.25);
}

.lede { color: var(--muted); font-size: 1.12rem; max-width: 34rem; margin: 0 0 2rem; }

.choices { display: flex; gap: 0.7rem; margin-bottom: 1.6rem; flex-wrap: wrap; }
.choices button {
  font-family: var(--mono);
  font-size: 0.85rem;
  width: 2.9rem;
  height: 2.9rem;
  border-radius: 50%;
  border: 1px solid var(--line);
  background: transparent;
  color: var(--muted);
  cursor: pointer;
  transition: all 0.25s;
}
.choices button:hover { border-color: var(--cyan); color: var(--cyan); box-shadow: 0 0 16px rgba(121, 231, 255, 0.25); }
.choices button.is-on {
  border-color: var(--chosen);
  color: var(--chosen);
  box-shadow: 0 0 22px rgba(255, 122, 60, 0.4), inset 0 0 12px rgba(255, 122, 60, 0.15);
}

.readout {
  border-left: 2px solid var(--chosen);
  padding: 0.4rem 0 0.4rem 1.1rem;
  margin: 0 0 1rem;
  min-height: 4.2rem;
}
.readout strong { display: block; font-family: var(--mono); font-size: 0.95rem; color: var(--amber); letter-spacing: 0.06em; }
.readout span { color: var(--muted); font-size: 0.98rem; }

.demo-note {
  font-family: var(--mono);
  font-size: 0.75rem;
  color: var(--dim);
  letter-spacing: 0.04em;
}
.demo-note::before { content: "// "; }

/* ---------- link rows instead of cards ---------- */
.grid {
  display: flex;
  flex-direction: column;
  padding: 4rem 0 8rem;
}

a.card {
  display: grid;
  grid-template-columns: 4rem 12rem 1fr;
  align-items: baseline;
  gap: 1.5rem;
  padding: 1.8rem 0.5rem;
  border-top: 1px solid var(--line);
  color: var(--ink);
  transition: background 0.25s, padding-left 0.25s;
}
a.card:last-child { border-bottom: 1px solid var(--line); }
a.card:hover {
  background: linear-gradient(90deg, rgba(121, 231, 255, 0.05), transparent 70%);
  padding-left: 1.4rem;
  text-shadow: none;
}
a.card em {
  font-family: var(--mono);
  font-style: normal;
  font-size: 0.8rem;
  color: var(--amber);
  letter-spacing: 0.2em;
}
a.card h2 { margin: 0; font-size: 1.5rem; font-weight: 600; color: #fff; }
a.card p { margin: 0; color: var(--muted); font-size: 0.98rem; }

/* ---------- inner pages: borderless column ---------- */
.page { padding: 9rem 0 7rem; }
.panel { max-width: 46rem; }
.panel .kicker {
  font-family: var(--mono);
  font-size: 0.78rem;
  letter-spacing: 0.32em;
  text-transform: uppercase;
  color: var(--cyan);
  margin: 0 0 1rem;
}
.panel .kicker::before { content: "∵ "; color: var(--amber); }
.panel h1 { font-size: clamp(2.2rem, 5vw, 3.4rem); }
.panel h2 {
  font-family: var(--mono);
  font-size: 0.9rem;
  letter-spacing: 0.24em;
  text-transform: uppercase;
  color: var(--amber);
  margin: 3rem 0 1rem;
  font-weight: 600;
}
.panel h2::after { content: " ⩆"; color: var(--dim); }
.panel p, .panel li { color: var(--muted); }
.panel .lede { color: var(--ink); font-size: 1.15rem; }
.panel ul, .panel dl { padding-left: 1.2rem; }
.panel li { margin: 0.4rem 0; }
.panel dt { color: var(--cyan); font-family: var(--mono); font-size: 0.9rem; margin-top: 1rem; }
.panel dd { margin: 0.2rem 0 0 0; color: var(--muted); }
.panel .note {
  font-family: var(--mono);
  font-size: 0.8rem;
  color: var(--dim);
  border-left: 2px solid var(--line);
  padding-left: 1rem;
  margin-top: 2.5rem;
}
.panel .note::before { content: "// "; }

/* ---------- footer ---------- */
footer.site {
  padding: 2.2rem 0;
  border-top: 1px solid var(--line);
  font-family: var(--mono);
  font-size: 0.78rem;
  color: var(--dim);
  letter-spacing: 0.06em;
}
footer.site .wrap { display: flex; justify-content: space-between; gap: 1rem; flex-wrap: wrap; }
footer.site nav { display: flex; gap: 1.4rem; }
footer.site a { color: var(--muted); }
footer.site a:hover { color: var(--cyan); }

/* ---------- responsive ---------- */
@media (max-width: 900px) {
  .stage { grid-template-columns: 1fr; padding-top: 7rem; gap: 1rem; }
  canvas[data-fork] { height: 40vh; order: 2; }
  a.card { grid-template-columns: 3rem 1fr; }
  a.card p { grid-column: 2; }
  .nav-group { gap: 1rem; }
  header.site nav { gap: 0.9rem; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  * { transition: none !important; }
}