/* Trustworthy AI Paper Reader — card UI, light & dark themes. */

:root {
  --bg: #f3f5f8;
  --panel: #ffffff;
  --card: #ffffff;
  --card-border: #e3e8ef;
  --text: #1c2430;
  --text-soft: #5b6675;
  --text-faint: #8b95a3;
  --accent: #2563eb;
  --accent-soft: #eaf1fe;
  --keyword-bg: #eaf1fe;
  --keyword-text: #2563eb;
  --badge-bg: #f1f4f8;
  --badge-text: #48545f;
  --venue-bg: #fff4e0;
  --venue-text: #9a6b12;
  --star: #f5a623;
  --star-card-bg: #fff5d9;
  --shadow: 0 1px 2px rgba(16, 24, 40, 0.05), 0 4px 16px rgba(16, 24, 40, 0.05);
  --sidebar-bg: #ffffff;
  --hover: #f5f8fc;
}
[data-theme="dark"] {
  --bg: #0f141a;
  --panel: #161d26;
  --card: #1a222d;
  --card-border: #263140;
  --text: #e6ebf2;
  --text-soft: #a8b3c2;
  --text-faint: #74808f;
  --accent: #5b8dff;
  --accent-soft: #1b2740;
  --keyword-bg: #1b2740;
  --keyword-text: #8db1ff;
  --badge-bg: #22303f;
  --badge-text: #a8b3c2;
  --venue-bg: #33290f;
  --venue-text: #e0b45c;
  --star: #f5a623;
  --star-card-bg: #2f2712;
  --shadow: 0 1px 2px rgba(0, 0, 0, 0.4);
  --sidebar-bg: #141b23;
  --hover: #1e2836;
}

* { box-sizing: border-box; }
html, body { margin: 0; padding: 0; }
body {
  background: var(--bg);
  color: var(--text);
  font: 15px/1.65 -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC",
    "Hiragino Sans GB", "Microsoft YaHei", "Noto Sans CJK SC", sans-serif;
}

/* ---------- top bar ---------- */

.topbar {
  position: sticky; top: 0; z-index: 20;
  display: flex; align-items: center; justify-content: space-between; gap: 16px;
  padding: 10px 20px;
  background: var(--panel);
  border-bottom: 1px solid var(--card-border);
  box-shadow: var(--shadow);
}
.brand { display: flex; align-items: center; gap: 10px; white-space: nowrap; }
.brand-mark { font-size: 20px; }
.brand-text { font-weight: 700; font-size: 16px; }
.brand-text em { font-style: normal; font-weight: 400; color: var(--text-faint); margin-left: 8px; font-size: 13px; }
.topbar-controls { display: flex; align-items: center; gap: 8px; flex: 1; justify-content: flex-end; }
#searchBox {
  width: min(420px, 40vw);
  padding: 8px 14px;
  border: 1px solid var(--card-border);
  border-radius: 999px;
  background: var(--bg);
  color: var(--text);
  font-size: 14px;
  outline: none;
}
#searchBox:focus { border-color: var(--accent); }
.chip, #themeToggle {
  border: 1px solid var(--card-border);
  background: var(--panel);
  color: var(--text-soft);
  border-radius: 999px;
  padding: 7px 14px;
  font-size: 13px;
  cursor: pointer;
  white-space: nowrap;
}
.chip:hover, #themeToggle:hover { background: var(--hover); }
.chip.on { background: var(--accent-soft); color: var(--accent); border-color: var(--accent); }

/* ---------- layout ---------- */

.layout { display: flex; min-height: calc(100vh - 57px); }
#sidebar {
  width: 264px; flex-shrink: 0;
  background: var(--sidebar-bg);
  border-right: 1px solid var(--card-border);
  padding: 14px 12px 24px;
  position: sticky; top: 57px;
  height: calc(100vh - 57px);
  overflow-y: auto;
}
#main { flex: 1; min-width: 0; padding: 20px clamp(14px, 4vw, 40px) 80px; max-width: 1180px; }

.view-tabs { display: flex; gap: 6px; margin-bottom: 14px; }
.view-tabs button {
  flex: 1; padding: 7px 0;
  border: 1px solid var(--card-border);
  border-radius: 8px;
  background: transparent;
  color: var(--text-soft);
  font-size: 13px;
  cursor: pointer;
}
.view-tabs button.active { background: var(--accent); border-color: var(--accent); color: #fff; font-weight: 600; }

.nav-tree { display: flex; flex-direction: column; gap: 2px; }
.nav-item {
  text-align: left;
  padding: 7px 10px;
  border: 0; border-radius: 8px;
  background: transparent;
  color: var(--text-soft);
  font-size: 13.5px;
  cursor: pointer;
  display: flex; justify-content: space-between; align-items: center; gap: 6px;
}
.nav-item:hover { background: var(--hover); }
.nav-item.active { background: var(--accent-soft); color: var(--accent); font-weight: 600; }
.nav-count { font-size: 11.5px; color: var(--text-faint); }
.nav-group { margin-top: 6px; }
.nav-group-header {
  width: 100%;
  display: flex; align-items: center; gap: 7px;
  padding: 7px 10px;
  border: 0; border-radius: 8px;
  background: transparent;
  color: var(--text);
  font-size: 13.5px; font-weight: 700;
  cursor: pointer;
  text-align: left;
}
.nav-group-header:hover { background: var(--hover); }
.nav-group-header .chev {
  font-size: 10px; color: var(--text-faint);
  transition: transform 0.15s ease;
  flex-shrink: 0;
}
.nav-group.open .nav-group-header .chev { transform: rotate(90deg); }
.nav-group-header .nav-count { margin-left: auto; }
.nav-group-items {
  display: flex; flex-direction: column; gap: 2px;
  padding-left: 10px;
  border-left: 1px solid var(--card-border);
  margin: 2px 0 4px 12px;
}
.nav-group-items[hidden] { display: none; }
.sidebar-foot { margin-top: 18px; padding: 0 10px; font-size: 11.5px; color: var(--text-faint); line-height: 1.7; }

/* ---------- scope header ---------- */

.scope-header h1 { margin: 4px 0 2px; font-size: 21px; }
.scope-meta { margin: 0 0 14px; color: var(--text-faint); font-size: 13px; }

.section-title {
  font-size: 16px; margin: 26px 0 10px; display: flex; align-items: center; gap: 8px;
}
.section-count {
  font-size: 11.5px; color: var(--accent);
  background: var(--accent-soft);
  padding: 1px 9px; border-radius: 999px;
}

/* ---------- cards ---------- */

.cards { display: flex; flex-direction: column; gap: 14px; }
.card {
  background: var(--card);
  border: 1px solid var(--card-border);
  border-radius: 12px;
  padding: 16px 18px 14px;
  box-shadow: var(--shadow);
  position: relative;
}
.card.starred {
  border-color: var(--star);
  background: var(--star-card-bg);
  box-shadow: 0 1px 3px rgba(245, 166, 35, 0.28), 0 4px 18px rgba(245, 166, 35, 0.18);
}
.card-head { display: flex; align-items: flex-start; justify-content: space-between; gap: 12px; }
.card-title {
  font-size: 16.5px; font-weight: 700; line-height: 1.45;
  color: var(--text); text-decoration: none;
}
.card-title:hover { color: var(--accent); }
.star {
  border: 0; background: transparent; cursor: pointer;
  font-size: 20px; line-height: 1;
  color: var(--text-faint);
  flex-shrink: 0; padding: 2px 4px;
}
.card.starred .star { color: var(--star); }
.star:hover { color: var(--star); }

.badges { display: flex; flex-wrap: wrap; gap: 6px; margin-top: 9px; }
.badge {
  font-size: 12px; font-weight: 600;
  padding: 2px 10px; border-radius: 999px;
  background: var(--badge-bg); color: var(--badge-text);
  text-decoration: none;
}
a.badge:hover { color: var(--accent); }
.badge-plain { background: var(--badge-bg); color: var(--text-faint); font-weight: 500; }
.badge-venue { background: var(--venue-bg); color: var(--venue-text); font-weight: 600; }

.keywords { display: flex; flex-wrap: wrap; gap: 6px; margin-top: 9px; }
.keyword {
  border: 0; cursor: pointer;
  font-size: 12px; padding: 2px 10px; border-radius: 999px;
  background: var(--keyword-bg); color: var(--keyword-text);
}
.keyword:hover { filter: brightness(0.95); }

.authors { margin-top: 9px; font-size: 13px; color: var(--text-soft); }

.summary { margin-top: 11px; display: flex; flex-direction: column; gap: 6px; }
.sum-row { display: flex; gap: 8px; font-size: 14px; align-items: baseline; }
.sum-icon { flex-shrink: 0; }
.sum-row b { flex-shrink: 0; color: var(--accent); font-size: 13px; }
.sum-row span:last-child { color: var(--text); }

.abstract { margin-top: 11px; }
.abstract summary {
  cursor: pointer; font-size: 13px; color: var(--accent); user-select: none;
  list-style: none;
}
.abstract summary::-webkit-details-marker { display: none; }
.abstract[open] summary { margin-bottom: 6px; }
.abstract p {
  margin: 0; padding: 10px 12px;
  background: var(--bg);
  border-left: 3px solid var(--card-border);
  border-radius: 6px;
  font-size: 13px; line-height: 1.7; color: var(--text-soft);
  text-align: justify;
}

/* ---------- misc ---------- */

.empty { text-align: center; padding: 80px 0; color: var(--text-faint); }
.empty-title { font-size: 16px; font-weight: 600; margin: 0 0 6px; }
.empty-hint { margin: 0; font-size: 13px; }

#backTop {
  position: fixed; right: 22px; bottom: 26px; z-index: 30;
  width: 40px; height: 40px; border-radius: 50%;
  border: 1px solid var(--card-border);
  background: var(--panel); color: var(--text-soft);
  font-size: 17px; cursor: pointer; box-shadow: var(--shadow);
}
#backTop:hover { color: var(--accent); }

.noscript { text-align: center; padding: 40px; }

@media (max-width: 900px) {
  .layout { flex-direction: column; }
  #sidebar { position: static; width: auto; height: auto; border-right: 0; border-bottom: 1px solid var(--card-border); }
  .topbar { flex-wrap: wrap; }
  #searchBox { width: 100%; }
  .topbar-controls { flex-basis: 100%; }
}

/* domain hierarchy */
.scope-crumb {
  margin: 0 0 2px;
  color: var(--muted, #8a8f98);
  font-size: 13px;
}
.scope-desc {
  margin: 6px 0 0;
  max-width: 72ch;
  color: var(--muted-strong, #5c6370);
  font-size: 13.5px;
  line-height: 1.65;
}
h2.leaf-title {
  margin: 34px 0 10px;
  font-size: 19px;
  display: flex;
  align-items: baseline;
  gap: 8px;
}
h3.section-title {
  margin: 22px 0 8px;
  font-size: 15.5px;
  display: flex;
  align-items: baseline;
  gap: 8px;
  opacity: 0.92;
}
.nav-group-header.active {
  font-weight: 700;
}

  border: 1px solid var(--border, #d0d7de);
  background: var(--card, #f6f8fa);
  color: var(--text, #1f2328);
  border-radius: 16px;
  padding: 4px 12px;
  font-size: 13px;
  cursor: pointer;
}
.band-nav button:hover { border-color: var(--accent, #0969da); color: var(--accent, #0969da); }
.band-nav .nav-count {
  margin-left: 5px;
  font-size: 11.5px;
  opacity: 0.65;
}