/* 黑客书架 — warm paper, quiet ink, one soft accent. */
:root {
  --bg: #faf8f4;
  --bg-soft: #f3efe7;
  --surface: #ffffff;
  --ink: #2a2723;
  --ink-2: #5d574f;
  --mute: #8d867c;
  --line: #ebe5da;
  --accent: #b4532f;
  --accent-soft: #f5e6dc;
  --chip: #efe9de;
  --shadow: 0 1px 2px rgba(60, 40, 20, .08), 0 8px 22px -12px rgba(60, 40, 20, .28);
  --serif: "Newsreader", "Noto Serif SC", "Songti SC", "STSong", "Source Han Serif SC", serif;
  --sans: -apple-system, BlinkMacSystemFont, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Noto Sans SC", "Segoe UI", sans-serif;
  --radius: 10px;
  --side: 232px;
  color-scheme: light;
}
/* 淡蓝：清晨天光，墨蓝文字，一点湖蓝做强调 */
:root[data-theme="blue"] {
  --bg: #f2f7fc; --bg-soft: #e6eef7; --surface: #ffffff; --ink: #1d2a3a; --ink-2: #47566a;
  --mute: #7d8b9d; --line: #dbe5f0; --accent: #2f6ea8; --accent-soft: #dceaf7; --chip: #e2ebf5;
  --shadow: 0 1px 2px rgba(30, 60, 100, .08), 0 8px 22px -12px rgba(30, 60, 100, .3);
  color-scheme: light;
}
:root[data-theme="dark"] {
  --bg: #1b1a18; --bg-soft: #232220; --surface: #262421; --ink: #ece7df; --ink-2: #c4bdb2;
  --mute: #8f887e; --line: #34312d; --accent: #e08a62; --accent-soft: #3a2a22; --chip: #2e2b28;
  --shadow: 0 1px 2px rgba(0, 0, 0, .3), 0 10px 24px -12px rgba(0, 0, 0, .6);
  color-scheme: dark;
}
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]):not([data-theme="blue"]) {
    --bg: #1b1a18; --bg-soft: #232220; --surface: #262421; --ink: #ece7df; --ink-2: #c4bdb2;
    --mute: #8f887e; --line: #34312d; --accent: #e08a62; --accent-soft: #3a2a22; --chip: #2e2b28;
    --shadow: 0 1px 2px rgba(0, 0, 0, .3), 0 10px 24px -12px rgba(0, 0, 0, .6);
    color-scheme: dark;
  }
}

* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }
body { margin: 0; background: var(--bg); color: var(--ink); font: 15px/1.7 var(--sans); -webkit-font-smoothing: antialiased; }
a { color: inherit; text-decoration: none; }
button { font: inherit; color: inherit; background: none; border: 0; cursor: pointer; padding: 0; }
svg { fill: none; stroke: currentColor; stroke-width: 1.6; stroke-linecap: round; stroke-linejoin: round; }
:focus-visible { outline: 2px solid var(--accent); outline-offset: 2px; border-radius: 4px; }
.skip { position: absolute; left: -999px; }
.skip:focus { left: 16px; top: 12px; z-index: 50; background: var(--surface); padding: 6px 12px; }

/* ---------- top bar ---------- */
.topbar {
  position: sticky; top: 0; z-index: 20; height: 60px; display: flex; align-items: center; gap: 16px;
  padding: 0 24px; background: color-mix(in srgb, var(--bg) 88%, transparent);
  backdrop-filter: saturate(1.4) blur(12px); -webkit-backdrop-filter: saturate(1.4) blur(12px);
  border-bottom: 1px solid var(--line);
}
.brand { font-family: var(--serif); font-weight: 600; font-size: 21px; letter-spacing: .1em; white-space: nowrap; }
.brand span { font-style: italic; font-weight: 400; letter-spacing: 0; font-size: 14px; color: var(--mute); margin-left: 8px; }
.search {
  flex: 1; min-width: 0; max-width: 460px; margin: 0 auto; display: flex; align-items: center; gap: 8px;
  background: var(--bg-soft); border: 1px solid transparent; border-radius: 999px; padding: 0 14px; height: 38px;
  color: var(--mute); transition: border-color .2s, background .2s;
}
.search:focus-within { background: var(--surface); border-color: var(--line); }
.search input { flex: 1; min-width: 0; border: 0; outline: 0; background: none; font: inherit; color: var(--ink); }
.search input::-webkit-search-cancel-button { display: none; }
.search kbd { font: 12px var(--sans); border: 1px solid var(--line); border-radius: 5px; padding: 0 6px; color: var(--mute); }
.actions { display: flex; gap: 4px; }
.icon-btn { width: 38px; height: 38px; display: grid; place-items: center; border-radius: 999px; color: var(--ink-2); }
.icon-btn:hover { background: var(--bg-soft); color: var(--ink); }
.menu-btn { display: none; }
.theme-wrap { position: relative; }
.theme-menu {
  position: absolute; right: 0; top: 44px; z-index: 40; min-width: 148px; padding: 6px; display: grid; gap: 2px;
  background: var(--surface); border: 1px solid var(--line); border-radius: 12px; box-shadow: var(--shadow);
}
.theme-menu[hidden] { display: none; }
.theme-menu button { display: flex; align-items: center; gap: 10px; padding: 7px 10px; border-radius: 8px; font-size: 14px; color: var(--ink-2); text-align: left; }
.theme-menu button:hover { background: var(--bg-soft); color: var(--ink); }
.theme-menu button[aria-checked="true"] { color: var(--accent); background: var(--accent-soft); }
.sw { width: 16px; height: 16px; border-radius: 50%; border: 1px solid rgba(0, 0, 0, .15); flex: none; }
.sw-light { background: #faf8f4; } .sw-blue { background: #cfe2f5; } .sw-dark { background: #1b1a18; }
.sw-auto { background: linear-gradient(135deg, #faf8f4 50%, #1b1a18 50%); }

/* ---------- layout ---------- */
.layout { display: grid; grid-template-columns: var(--side) minmax(0, 1fr); }
.sidebar {
  position: sticky; top: 60px; height: calc(100vh - 60px); overflow-y: auto; padding: 28px 16px 40px 24px;
  border-right: 1px solid var(--line); scrollbar-width: thin;
}
.nav { display: flex; flex-direction: column; gap: 2px; padding-bottom: 20px; border-bottom: 1px solid var(--line); }
.nav a, .topic-nav a {
  display: flex; justify-content: space-between; align-items: baseline; padding: 6px 12px; border-radius: 8px; color: var(--ink-2);
}
.nav a { font-size: 15px; }
.nav a:hover, .topic-nav a:hover { background: var(--bg-soft); color: var(--ink); }
.nav a.on, .topic-nav a.on { background: var(--accent-soft); color: var(--accent); }
.topic-nav h4 { margin: 22px 12px 6px; font: 500 12px var(--sans); letter-spacing: .12em; color: var(--mute); }
.topic-nav a { font-size: 14px; padding: 4px 12px; }
.topic-nav a small { font-size: 12px; color: var(--mute); font-variant-numeric: tabular-nums; }
.scrim { display: none; }
main { min-width: 0; padding: 44px 48px 80px; outline: 0; }
.loading, .empty { color: var(--mute); padding: 40px 0; }

/* ---------- page head ---------- */
.page-head h1 { font: 600 34px/1.3 var(--serif); letter-spacing: .04em; margin: 0; }
.page-head p { margin: 10px 0 0; color: var(--ink-2); max-width: 46em; }
.page-head p a { color: var(--accent); }
.filters { margin: 26px 0 8px; display: grid; gap: 10px; }
.frow { display: flex; align-items: center; gap: 4px; flex-wrap: wrap; }
.frow > span { font-size: 13px; color: var(--mute); width: 64px; flex: none; }
.frow button { font-size: 14px; padding: 3px 11px; border-radius: 999px; color: var(--ink-2); }
.frow button:hover { background: var(--bg-soft); }
.frow button.on { background: var(--ink); color: var(--bg); }

/* ---------- grid & cards ---------- */
.grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(156px, 1fr)); gap: 40px 28px; margin-top: 30px; }
.card { display: block; position: relative; border-radius: 6px; }
.card .cv { transition: transform .25s ease, box-shadow .25s ease; }
.card:hover .cv, .card.kb .cv { transform: translateY(-3px); box-shadow: 0 2px 4px rgba(60,40,20,.1), 0 16px 28px -14px rgba(60,40,20,.4); }
.card.kb { outline: 2px solid var(--accent); outline-offset: 6px; }
.cv {
  aspect-ratio: 2 / 3; border-radius: 4px; overflow: hidden; background: var(--bg-soft); box-shadow: var(--shadow); position: relative;
}
.cv img { width: 100%; height: 100%; object-fit: cover; display: block; }
.cv.ph { display: flex; flex-direction: column; justify-content: space-between; padding: 14px 12px; color: #fbf6ee; background: var(--ph, #6b5a4a); }
.cv.ph::before { content: ""; position: absolute; left: 5px; top: 0; bottom: 0; width: 1px; background: rgba(255,255,255,.14); }
.cv.ph b { font: 500 16px/1.25 var(--serif); }
.cv.ph i { font: italic 12px var(--serif); opacity: .8; }
.rank { position: absolute; top: 8px; left: 8px; font: 500 12px var(--serif); background: color-mix(in srgb, var(--bg) 92%, transparent); color: var(--ink); border-radius: 999px; padding: 0 8px; }
.card h3 { font: 600 16px/1.45 var(--serif); margin: 14px 0 0; display: -webkit-box; -webkit-line-clamp: 2; -webkit-box-orient: vertical; overflow: hidden; }
.card .en { font: italic 14px/1.4 var(--serif); color: var(--mute); margin-top: 2px; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
.card .au { font-size: 13px; color: var(--ink-2); margin-top: 2px; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
.card .stat { font-size: 13px; color: var(--mute); margin-top: 6px; font-variant-numeric: tabular-nums; }
.card .stat b { color: var(--accent); font-weight: 500; }
.card .w { font-size: 13px; color: var(--ink-2); margin: 6px 0 0; line-height: 1.6; display: -webkit-box; -webkit-line-clamp: 2; -webkit-box-orient: vertical; overflow: hidden; }
.more { display: block; margin: 48px auto 0; padding: 9px 26px; border: 1px solid var(--line); border-radius: 999px; color: var(--ink-2); }
.more:hover { border-color: var(--ink-2); color: var(--ink); }
.foot { margin-top: 72px; padding-top: 20px; border-top: 1px solid var(--line); font-size: 13px; color: var(--mute); line-height: 1.9; }
.foot a { text-decoration: underline; text-underline-offset: 3px; text-decoration-color: var(--line); }

/* ---------- book detail ---------- */
.back { font-size: 14px; color: var(--mute); display: inline-flex; gap: 6px; align-items: center; }
.back:hover { color: var(--ink); }
.book { display: grid; grid-template-columns: 220px minmax(0, 1fr); gap: 44px; margin-top: 24px; max-width: 1000px; }
.book .cv { border-radius: 5px; }
.book h1 { font: 600 34px/1.3 var(--serif); margin: 0; letter-spacing: .02em; }
.book .en { font: italic 20px/1.4 var(--serif); color: var(--ink-2); margin-top: 6px; }
.book .au { margin-top: 10px; color: var(--ink-2); }
.book .w { margin-top: 16px; font-size: 16px; color: var(--ink-2); }
.nums { display: flex; flex-wrap: wrap; gap: 12px 36px; margin-top: 24px; padding-top: 18px; border-top: 1px solid var(--line); }
.nums div { display: flex; flex-direction: column; }
.nums b { font: 500 28px/1.2 var(--serif); font-variant-numeric: tabular-nums; }
.nums b.ac { color: var(--accent); }
.nums span { font-size: 13px; color: var(--mute); }
.tags { display: flex; flex-wrap: wrap; gap: 8px; margin-top: 20px; }
.tags a { font-size: 13px; padding: 2px 12px; border-radius: 999px; background: var(--chip); color: var(--ink-2); }
.tags a:hover { color: var(--ink); }
.links { display: flex; flex-wrap: wrap; gap: 10px; margin-top: 22px; }
.btn { display: inline-flex; align-items: center; gap: 6px; font-size: 14px; padding: 7px 16px; border-radius: 999px; border: 1px solid var(--line); color: var(--ink-2); }
.btn:hover { border-color: var(--ink-2); color: var(--ink); }
.btn.on { background: var(--accent-soft); border-color: transparent; color: var(--accent); }
.btn.on svg { fill: currentColor; }
.section-title { font: 600 22px var(--serif); margin: 56px 0 6px; letter-spacing: .04em; }
.section-note { font-size: 13px; color: var(--mute); margin: 0 0 18px; }
.quotes { display: grid; gap: 18px; max-width: 760px; }
.quote { margin: 0; background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius); padding: 18px 22px; }
.quote p { margin: 0 0 .6em; font: 16px/1.75 var(--serif); white-space: pre-line; overflow-wrap: anywhere; color: var(--ink); }
.quote footer { margin-top: 10px; font-size: 13px; color: var(--mute); display: flex; flex-wrap: wrap; gap: 4px 10px; }
.quote footer a:hover { color: var(--accent); }
.grid.small { grid-template-columns: repeat(auto-fill, minmax(124px, 1fr)); gap: 28px 20px; margin-top: 18px; }
.grid.small h3 { font-size: 14px; }

/* ---------- prose (about) ---------- */
.prose { max-width: 680px; }
.prose h1 { font: 600 34px/1.3 var(--serif); margin: 0 0 18px; }
.prose h2 { font: 600 20px var(--serif); margin: 36px 0 8px; }
.prose p, .prose li { color: var(--ink-2); }
.prose a { color: var(--accent); }

/* ---------- shortcuts dialog ---------- */
dialog { border: 1px solid var(--line); border-radius: 14px; background: var(--surface); color: var(--ink); padding: 24px 28px; box-shadow: var(--shadow); }
dialog::backdrop { background: rgba(20, 16, 12, .35); }
dialog h3 { font: 600 18px var(--serif); margin: 0 0 12px; }
dialog dl { display: grid; grid-template-columns: auto 1fr; gap: 6px 18px; margin: 0; font-size: 14px; }
dialog dt kbd { font: 12px var(--sans); border: 1px solid var(--line); border-radius: 5px; padding: 1px 7px; }

/* ---------- responsive ---------- */
@media (max-width: 900px) {
  .menu-btn { display: grid; }
  .brand span, .search kbd, .actions a.icon-btn { display: none; }
  .brand { font-size: 19px; letter-spacing: .06em; }
  .topbar { padding: 0 12px 0 8px; gap: 8px; }
  .layout { grid-template-columns: minmax(0, 1fr); }
  .sidebar {
    position: fixed; z-index: 30; top: 0; left: 0; height: 100vh; width: 270px; background: var(--bg);
    transform: translateX(-100%); transition: transform .25s ease; padding-top: 24px;
  }
  body.nav-open .sidebar { transform: none; box-shadow: var(--shadow); }
  body.nav-open .scrim { display: block; position: fixed; inset: 0; z-index: 25; background: rgba(20, 16, 12, .3); }
  main { padding: 28px 16px 64px; }
  .page-head h1, .book h1, .prose h1 { font-size: 28px; }
  .grid { grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 30px 16px; margin-top: 22px; }
  .grid.small { grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 20px 12px; }
  .frow { flex-wrap: nowrap; overflow-x: auto; scrollbar-width: none; margin-right: -16px; padding-right: 16px; }
  .frow::-webkit-scrollbar { display: none; }
  .frow button { white-space: nowrap; }
  .book { grid-template-columns: minmax(0, 1fr); gap: 24px; }
  .book > .cv { width: 160px; }
  .quote { padding: 16px; }
}
@media (prefers-reduced-motion: reduce) { * { transition: none !important; } }