:root {
  --bg: #fbfbf9; --fg: #1f2328; --muted: #6b6f76; --line: #e3e3de;
  --code-bg: #f3f3ef; --accent: #1f5fbf; --side: 240px;
}
@media (prefers-color-scheme: dark) {
  :root { --bg: #16181c; --fg: #e6e6e3; --muted: #9a9ea6; --line: #2c2f35; --code-bg: #1e2126; --accent: #7aa9ff; }
}
* { box-sizing: border-box; }
body {
  margin: 0; background: var(--bg); color: var(--fg);
  font: 16px/1.7 -apple-system, "PingFang TC", "Noto Sans TC", "Microsoft JhengHei", sans-serif;
}
a { color: var(--accent); text-decoration: none; }
a:hover { text-decoration: underline; }

.top {
  position: sticky; top: 0; z-index: 10; height: 52px; padding: 0 16px;
  display: flex; align-items: center; justify-content: space-between;
  background: var(--bg); border-bottom: 1px solid var(--line);
}
.brand { color: var(--fg); font-weight: 700; }
.burger { display: none; font-size: 22px; cursor: pointer; padding: 4px 8px; }

.shell { display: grid; grid-template-columns: var(--side) minmax(0, 1fr); }
.side {
  position: sticky; top: 52px; height: calc(100vh - 52px); overflow-y: auto;
  padding: 20px 16px; border-right: 1px solid var(--line);
}
.side details { margin-bottom: 4px; }
.side summary {
  cursor: pointer; padding: 6px 8px; border-radius: 6px; font-size: 14px; font-weight: 600;
  display: flex; align-items: center; list-style: none;
}
.side summary::-webkit-details-marker { display: none; }
.side summary::before { content: "▸"; color: var(--muted); margin-right: 6px; transition: transform .15s; }
.side details[open] > summary::before { transform: rotate(90deg); }
.side summary span { margin-left: auto; color: var(--muted); font-weight: 400; font-size: 12px; }
.side summary:hover { background: var(--code-bg); }
.side ul { list-style: none; margin: 2px 0 8px 14px; padding: 0; }
.side a { display: block; padding: 5px 8px; border-radius: 6px; color: var(--fg); }
.side a { display: flex; justify-content: space-between; gap: 8px; font-size: 14px; }
.side a span { color: var(--muted); font-size: 12px; }
.side a:hover { background: var(--code-bg); text-decoration: none; }
.side a[aria-current] { background: var(--code-bg); font-weight: 600; }

.content { padding: 28px 32px 64px; min-width: 0; }
.content h1 { margin: 0 0 4px; font-size: 28px; line-height: 1.3; }
.meta { color: var(--muted); font-size: 14px; margin: 0 0 8px; }
.summary { margin: 0 0 24px; }

/* 中英對照：寬螢幕並排，窄螢幕上下疊（中文在前） */
.pair { display: grid; grid-template-columns: 1fr 1fr; gap: 20px; }
.pair h2 { font-size: 16px; margin: 0 0 8px; }
.pair.single { grid-template-columns: 1fr; max-width: 900px; }
pre, code { font-family: ui-monospace, "SF Mono", Menlo, monospace; font-size: 13.5px; }
pre {
  margin: 0; padding: 16px; background: var(--code-bg); border: 1px solid var(--line);
  border-radius: 8px; white-space: pre-wrap; word-break: break-word; line-height: 1.65;
}
/* 並排時兩邊各自捲動，方便對照 */
.pair pre { max-height: calc(100vh - 140px); overflow: auto; }

/* 首頁 */
.search {
  width: 100%; max-width: 480px; padding: 10px 14px; font: inherit; color: var(--fg);
  background: var(--bg); border: 1px solid var(--line); border-radius: 8px;
}
.search:focus { outline: 2px solid var(--accent); outline-offset: 1px; }
.cat { margin: 32px 0 12px; font-size: 18px; }
.cards { display: grid; grid-template-columns: repeat(auto-fill, minmax(260px, 1fr)); gap: 12px; }
.cards a {
  display: block; padding: 14px 16px; border: 1px solid var(--line); border-radius: 8px; color: var(--fg);
}
.cards a:hover { border-color: var(--accent); text-decoration: none; }
.cards strong { display: block; }
.cards small { color: var(--muted); }
.cards p { margin: 6px 0 0; font-size: 14px; }
.cards.compact { grid-template-columns: repeat(auto-fill, minmax(150px, 1fr)); }

@media (max-width: 1100px) {
  .pair { grid-template-columns: 1fr; }
  .pair pre { max-height: none; }
}
@media (max-width: 760px) {
  .burger { display: block; }
  .shell { display: block; }
  .side {
    display: none; position: fixed; inset: 52px 0 0 0; height: auto;
    background: var(--bg); border-right: 0; z-index: 9;
  }
  #nav-toggle:checked ~ .shell .side { display: block; }
  .content { padding: 20px 16px 48px; }
  .content h1 { font-size: 24px; }
}