:root {
  --bg: #080808;
  --panel: #111111;
  --text: #ededed;
  --muted: #a6a6a6;
  --faint: #6e6e6e;
  --line: #262626;
  --accent: #ffc14d;
  --measure: 40rem;
  --font: "Inter", "Noto Sans TC", "PingFang TC", "Microsoft JhengHei", system-ui, -apple-system, "Segoe UI", sans-serif;
  color-scheme: dark;
}

* { box-sizing: border-box; }

html { -webkit-text-size-adjust: 100%; }

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: var(--font);
  font-size: 1rem;
  line-height: 1.75;
  letter-spacing: 0.01em;
  -webkit-font-smoothing: antialiased;
}

a { color: var(--text); text-decoration-color: var(--faint); text-underline-offset: 0.2em; }
a:hover { text-decoration-color: var(--accent); }
a:focus-visible { outline: 2px solid var(--accent); outline-offset: 3px; border-radius: 2px; }

.wrap { width: min(100% - 2rem, 64rem); margin-inline: auto; }

/* ---------- header ---------- */
.top {
  display: flex; align-items: center; justify-content: space-between;
  padding-block: 1.25rem;
}
.brand { display: inline-flex; align-items: center; gap: 0.6rem; text-decoration: none; font-weight: 600; letter-spacing: 0.04em; }
.brand svg { width: 1.75rem; height: 1.75rem; }
.top nav { display: flex; gap: 1.25rem; font-size: 0.875rem; }
.top nav a { color: var(--muted); text-decoration: none; }
.top nav a:hover, .top nav a[aria-current="page"] { color: var(--text); }

/* ---------- hero ---------- */
.hero {
  position: relative;
  min-height: min(78vh, 44rem);
  display: grid; place-items: center;
  text-align: center;
  padding: 4rem 1rem;
  margin-top: 1rem;
}
.frame { position: absolute; inset: 0; pointer-events: none; }
.frame i { position: absolute; width: 2.5rem; height: 2.5rem; border-color: rgba(237, 237, 237, 0.4); border-style: solid; border-width: 0; }
.frame i:nth-child(1) { top: 0; left: 0; border-top-width: 1px; border-left-width: 1px; }
.frame i:nth-child(2) { top: 0; right: 0; border-top-width: 1px; border-right-width: 1px; }
.frame i:nth-child(3) { bottom: 0; left: 0; border-bottom-width: 1px; border-left-width: 1px; }
.frame i:nth-child(4) { bottom: 0; right: 0; border-bottom-width: 1px; border-right-width: 1px; }
.readout {
  position: absolute; bottom: 1rem; left: 50%; transform: translateX(-50%);
  font-size: 0.75rem; letter-spacing: 0.18em; color: var(--muted);
  font-variant-numeric: tabular-nums; white-space: nowrap;
}
.readout b { color: var(--accent); font-weight: 500; }

.mark { width: clamp(4.5rem, 12vw, 6.5rem); height: auto; margin-bottom: 2rem; }
.hero h1 { margin: 0; font-size: clamp(2.75rem, 8vw, 4.5rem); font-weight: 300; letter-spacing: 0.12em; line-height: 1.1; }
.tagline { margin: 1.25rem 0 0; font-size: clamp(1.05rem, 2.6vw, 1.3rem); color: var(--text); letter-spacing: 0.08em; }
.tagline-en { margin: 0.35rem 0 0; color: var(--muted); font-size: 0.9rem; letter-spacing: 0.06em; }
.status {
  display: inline-flex; align-items: center; gap: 0.55rem;
  margin-top: 2.5rem; padding: 0.55rem 1.1rem;
  border: 1px solid var(--line); border-radius: 999px;
  color: var(--muted); font-size: 0.85rem;
}
.status::before { content: ""; width: 0.45rem; height: 0.45rem; border-radius: 50%; background: var(--accent); }

/* ---------- features ---------- */
.features {
  display: grid; grid-template-columns: repeat(auto-fit, minmax(13rem, 1fr));
  gap: 1px; background: var(--line);
  border-block: 1px solid var(--line);
  margin-block: 5rem;
}
.feature { background: var(--bg); padding: 2rem 1.5rem; }
.feature .num { display: block; font-size: 2rem; font-weight: 300; letter-spacing: 0.04em; font-variant-numeric: tabular-nums; }
.feature .num small { font-size: 0.9rem; color: var(--muted); margin-left: 0.2rem; }
.feature h2 { margin: 0.75rem 0 0.35rem; font-size: 1rem; font-weight: 600; }
.feature p { margin: 0; color: var(--muted); font-size: 0.9rem; line-height: 1.7; }
.feature p.en { margin-top: 0.4rem; color: var(--faint); font-size: 0.8rem; }

.statement { max-width: var(--measure); margin: 0 auto 6rem; text-align: center; color: var(--muted); }
.statement p { margin: 0 0 0.5rem; }
.statement .en { font-size: 0.875rem; color: var(--faint); }

/* ---------- document pages ---------- */
.doc { max-width: var(--measure); margin: 3rem auto 6rem; }
.doc h1 { font-size: clamp(1.75rem, 5vw, 2.25rem); font-weight: 400; letter-spacing: 0.04em; margin: 0; line-height: 1.3; }
.doc .meta { color: var(--faint); font-size: 0.85rem; margin: 0.75rem 0 0; }
.langs { display: flex; gap: 0.5rem; margin: 2rem 0 0; }
.langs a { font-size: 0.8rem; color: var(--muted); text-decoration: none; padding: 0.3rem 0.8rem; border: 1px solid var(--line); border-radius: 999px; }
.langs a:hover { color: var(--text); border-color: var(--faint); }
.doc section { margin-top: 3.5rem; padding-top: 2.5rem; border-top: 1px solid var(--line); }
.doc section > h2 { font-size: 0.75rem; letter-spacing: 0.2em; text-transform: uppercase; color: var(--accent); font-weight: 500; margin: 0 0 1.5rem; }
.doc h3 { font-size: 1.05rem; font-weight: 600; margin: 2.25rem 0 0.5rem; }
.doc p, .doc li { color: #cfcfcf; }
.doc ul, .doc ol { padding-left: 1.25rem; }
.doc li { margin-bottom: 0.4rem; }
.doc li::marker { color: var(--faint); }
.callout {
  margin: 1.5rem 0; padding: 1.25rem 1.5rem;
  background: var(--panel); border: 1px solid var(--line); border-left: 2px solid var(--accent);
  border-radius: 0.5rem;
}
.callout p { margin: 0.25rem 0; }
.callout .mail { font-size: 1.1rem; color: var(--text); }
code, .mono { font-family: ui-monospace, "Cascadia Mono", Consolas, monospace; font-size: 0.9em; color: var(--text); }

/* ---------- footer ---------- */
footer { border-top: 1px solid var(--line); padding-block: 2rem 3rem; font-size: 0.85rem; color: var(--faint); }
footer .wrap { display: flex; flex-wrap: wrap; gap: 1rem 2rem; justify-content: space-between; align-items: center; }
footer nav { display: flex; flex-wrap: wrap; gap: 1.25rem; }
footer a { color: var(--muted); text-decoration: none; }
footer a:hover { color: var(--text); }

@media (max-width: 30rem) {
  .top nav { gap: 0.9rem; }
  .readout { letter-spacing: 0.1em; }
}

@media (prefers-reduced-motion: no-preference) {
  .hero > div { animation: rise 1.2s cubic-bezier(.2, .7, .2, 1) both; }
  .frame { animation: fade 1.6s ease both 0.2s; }
  @keyframes rise { from { opacity: 0; transform: translateY(0.75rem); } to { opacity: 1; transform: none; } }
  @keyframes fade { from { opacity: 0; } to { opacity: 1; } }
}