:root {
  --bg: #f4f6f8;
  --panel: #ffffff;
  --ink: #16212b;
  --ink-soft: #55666f;
  --line: #dfe5ea;
  --accent: #0f766e;
  --accent-ink: #ffffff;
  --radius: 14px;
  --shadow: 0 1px 2px rgba(22, 33, 43, 0.06), 0 8px 24px rgba(22, 33, 43, 0.06);
  color-scheme: light dark;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #0f1720;
    --panel: #17222c;
    --ink: #e8eef2;
    --ink-soft: #9fb1bc;
    --line: #26333f;
    --accent: #2dd4bf;
    --accent-ink: #06231f;
    --shadow: none;
  }
}

* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  font: 16px/1.5 -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue",
    "PingFang TC", "PingFang SC", "Hiragino Sans GB", "Noto Sans CJK TC", "Noto Sans CJK SC", sans-serif;
  padding-bottom: env(safe-area-inset-bottom);
}

.masthead {
  background: var(--accent);
  color: #f0fdfa;
  padding: 1.2rem 1rem;
  text-align: center;
}
.masthead h1 { margin: 0; font-size: 1.4rem; }
.masthead .tagline { margin: 0.2rem 0 0; font-size: 0.9rem; }
.masthead.slim { padding: 0.8rem 1rem; }

.locale {
  display: inline-flex;
  gap: 1rem;
  margin: 0.7rem 0 0;
  padding: 0.3rem 0.8rem;
  border: 1px solid rgba(255, 255, 255, 0.35);
  border-radius: 999px;
  font-size: 0.8rem;
}
.locale legend {
  position: absolute; width: 1px; height: 1px; overflow: hidden; clip: rect(0 0 0 0);
}
.locale label {
  display: inline-flex; align-items: center; gap: 0.3rem; cursor: pointer;
}

main { max-width: 44rem; margin: 0 auto; padding: 2rem 1.25rem 3rem; }
.prose { line-height: 1.65; }
.prose h1 { font-size: 1.5rem; margin: 0 0 0.4rem; }
.prose h2 { font-size: 1.1rem; margin: 1.5rem 0 0.4rem; }
.prose p { margin: 0.45rem 0; }
.prose code {
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: 4px;
  padding: 0.1rem 0.35rem;
  font-size: 0.88em;
}
.prose a { color: var(--accent); }
.prose strong { font-weight: 650; }

.site-footer {
  text-align: center;
  color: var(--ink-soft);
  font-size: 0.82rem;
  padding: 1.2rem 1rem 2rem;
}
.site-footer a { color: var(--accent); text-decoration: none; }