:root {
  --bg: #fbfbf9;
  --fg: #1d1f21;
  --muted: #6b6f76;
  --line: #e4e4de;
  --card: #ffffff;
  --accent: #2455a4;
  --chip: #eef1f6;
  --chip-fg: #35507a;
  --max: 1080px;
}
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --bg: #131416; --fg: #e8e8e4; --muted: #9a9ea6; --line: #2a2c30; --card: #1b1d21;
    --accent: #7fb0ff; --chip: #23272e; --chip-fg: #b8c6de;
  }
}
:root[data-theme="dark"] {
  --bg: #131416; --fg: #e8e8e4; --muted: #9a9ea6; --line: #2a2c30; --card: #1b1d21;
  --accent: #7fb0ff; --chip: #23272e; --chip-fg: #b8c6de;
}

* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--fg);
  font: 16px/1.65 -apple-system, BlinkMacSystemFont, "Segoe UI", "Noto Sans TC", "PingFang TC", "Microsoft JhengHei", Helvetica, Arial, sans-serif;
}
a { color: var(--accent); text-decoration: none; }
a:hover { text-decoration: underline; }
code { font-family: ui-monospace, SFMono-Regular, Consolas, Menlo, monospace; font-size: 0.9em; background: var(--chip); padding: 0.1em 0.35em; border-radius: 4px; }

.wrap { max-width: var(--max); margin: 0 auto; padding: 0 16px; }

.hero { padding: 56px 0 28px; border-bottom: 1px solid var(--line); }
.handle { margin: 0; color: var(--muted); font-size: 0.9rem; letter-spacing: 0.02em; }
.hero h1 { margin: 4px 0 12px; font-size: clamp(2rem, 5vw, 3rem); line-height: 1.1; letter-spacing: -0.02em; }
.tagline { margin: 0 0 4px; max-width: 46em; font-size: 1.1rem; }
.tagline-en { margin: 0 0 18px; max-width: 46em; color: var(--muted); }
.links a { display: inline-block; margin-right: 14px; padding: 6px 12px; border: 1px solid var(--line); border-radius: 999px; font-size: 0.92rem; }
.links a:hover { border-color: var(--accent); text-decoration: none; }

section { padding: 36px 0 8px; }
h2 { font-size: 1.4rem; margin: 0 0 16px; letter-spacing: -0.01em; }
.en { color: var(--muted); font-weight: 400; font-size: 0.85em; }
.group-title { margin: 28px 0 10px; font-size: 1.05rem; }
.count { color: var(--muted); font-weight: 400; font-size: 0.85em; }
.muted { color: var(--muted); }

.grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(300px, 1fr)); gap: 14px; }
.card {
  display: flex; flex-direction: column; gap: 8px;
  background: var(--card); border: 1px solid var(--line); border-radius: 12px; padding: 16px 16px 14px;
  transition: border-color 0.15s, transform 0.15s;
}
.card:hover { border-color: var(--accent); transform: translateY(-1px); }
.card h3 { margin: 0; font-size: 1.05rem; word-break: break-word; }
.card .desc { margin: 0; flex: 1; font-size: 0.95rem; }
.topics { display: flex; flex-wrap: wrap; gap: 6px; }
.chip { background: var(--chip); color: var(--chip-fg); border-radius: 999px; padding: 1px 9px; font-size: 0.78rem; }
.meta { display: flex; flex-wrap: wrap; gap: 12px; font-size: 0.82rem; color: var(--muted); }
.lang i { display: inline-block; width: 10px; height: 10px; border-radius: 50%; margin-right: 5px; vertical-align: -1px; }
.card-links { display: flex; gap: 14px; font-size: 0.9rem; }

#about-body p { max-width: 46em; }
footer { padding: 40px 16px 32px; border-top: 1px solid var(--line); margin-top: 40px; font-size: 0.9rem; }

@media (max-width: 480px) {
  .hero { padding-top: 40px; }
  .grid { grid-template-columns: 1fr; }
}