* {
  box-sizing: border-box;
}

:root {
  --bg: #f3f6fb;
  --surface: #ffffff;
  --surface-soft: #f8fbfa;
  --ink: #163238;
  --muted: #657780;
  --primary: #0f766e;
  --primary-dark: #0b4f4a;
  --primary-soft: #dff4ef;
  --accent: #d97706;
  --accent-soft: #fff3df;
  --line: #cbdde3;
  --shadow: 0 18px 45px rgba(20, 57, 64, 0.11);
}

body {
  margin: 0;
  color: var(--ink);
  background:
    linear-gradient(180deg, #e8f2f5 0, var(--bg) 340px),
    var(--bg);
  font-family: "Microsoft JhengHei", "PingFang TC", "Noto Sans TC", Arial, sans-serif;
  line-height: 1.7;
}

a {
  color: var(--primary-dark);
  text-decoration-color: rgba(15, 118, 110, 0.35);
  text-underline-offset: 3px;
}

.index-shell {
  width: min(1120px, calc(100% - 32px));
  margin: 0 auto;
  padding: 34px 0 56px;
}

.index-header {
  margin-bottom: 20px;
  padding: 30px;
  border: 1px solid rgba(255, 255, 255, 0.6);
  border-radius: 8px;
  color: white;
  background:
    linear-gradient(135deg, rgba(15, 118, 110, 0.96), rgba(18, 52, 59, 0.96)),
    linear-gradient(90deg, rgba(255, 255, 255, 0.16), transparent);
  box-shadow: var(--shadow);
}

.index-header h1 {
  margin: 0 0 10px;
  font-size: clamp(2.1rem, 5vw, 3.5rem);
  line-height: 1.12;
  letter-spacing: 0;
}

.index-header p,
.page-header p,
#result-count {
  margin: 0;
  color: var(--muted);
}

.index-header p {
  color: rgba(255, 255, 255, 0.82);
}

.search-panel {
  position: sticky;
  top: 0;
  z-index: 2;
  margin: 0 0 20px;
  padding: 16px 0;
  background: rgba(243, 246, 251, 0.92);
  backdrop-filter: blur(10px);
}

#search {
  width: 100%;
  height: 52px;
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 0 16px;
  color: var(--ink);
  font: inherit;
  background: var(--surface);
  box-shadow: 0 10px 25px rgba(20, 57, 64, 0.08);
}

#search:focus {
  border-color: var(--primary);
  outline: 4px solid rgba(15, 118, 110, 0.16);
}

#result-count {
  margin-top: 8px;
}

.results {
  display: grid;
  gap: 12px;
}

.result {
  position: relative;
  display: block;
  overflow: hidden;
  padding: 18px 18px 18px 22px;
  border: 1px solid var(--line);
  border-radius: 8px;
  color: inherit;
  text-decoration: none;
  background: var(--surface);
  box-shadow: 0 8px 22px rgba(20, 57, 64, 0.06);
  transition: transform 160ms ease, border-color 160ms ease, box-shadow 160ms ease;
}

.result::before {
  position: absolute;
  inset: 0 auto 0 0;
  width: 5px;
  background: var(--primary);
  content: "";
}

.result:hover,
.result:focus {
  transform: translateY(-2px);
  border-color: rgba(15, 118, 110, 0.55);
  box-shadow: 0 16px 34px rgba(20, 57, 64, 0.13);
  outline: none;
}

.result h2 {
  margin: 0 0 6px;
  font-size: 1.1rem;
  line-height: 1.4;
}

.result .source {
  margin: 0 0 8px;
  color: var(--muted);
  font-size: 0.92rem;
}

.result .summary {
  margin: 0;
  color: #334a52;
}

.empty {
  padding: 28px;
  border: 1px dashed #9eb7be;
  border-radius: 8px;
  color: var(--primary-dark);
  background: var(--surface);
}

.page-header {
  width: min(980px, calc(100% - 32px));
  margin: 0 auto;
  padding: 28px 0 18px;
}

.page-header h1 {
  margin: 10px 0 6px;
  font-size: clamp(1.7rem, 3vw, 2.5rem);
  line-height: 1.25;
}

.back-link {
  display: inline-flex;
  align-items: center;
  min-height: 32px;
  padding: 0 10px;
  border-radius: 8px;
  color: var(--primary-dark);
  background: var(--primary-soft);
  font-weight: 700;
  text-decoration: none;
}

.back-link:hover,
.back-link:focus {
  outline: 3px solid rgba(15, 118, 110, 0.16);
}

.document {
  width: min(980px, calc(100% - 32px));
  margin: 0 auto 56px;
  padding: 28px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--surface);
  box-shadow: 0 8px 24px rgba(20, 57, 64, 0.08);
}

.document h1,
.document h2,
.document h3 {
  color: var(--ink);
}

.document h2 {
  margin-top: 1.4em;
  padding-left: 12px;
  border-left: 4px solid var(--accent);
}

.document blockquote {
  margin: 1em 0;
  padding: 10px 14px;
  border-left: 4px solid var(--primary);
  color: var(--primary-dark);
  background: var(--primary-soft);
}

.document img {
  max-width: 100%;
  height: auto;
  border-radius: 6px;
}

.document math {
  max-width: 100%;
  overflow-x: auto;
  overflow-y: hidden;
  vertical-align: middle;
}

.document math[display="block"] {
  display: block;
  margin: 1em 0;
}

.document table {
  display: block;
  max-width: 100%;
  overflow-x: auto;
  border-collapse: collapse;
  border: 1px solid var(--line);
  border-radius: 8px;
}

.document th,
.document td {
  border: 1px solid var(--line);
  padding: 6px 8px;
  vertical-align: top;
}

.document th {
  color: var(--primary-dark);
  background: var(--primary-soft);
}

.document pre {
  overflow-x: auto;
  padding: 12px;
  border-left: 4px solid var(--accent);
  border-radius: 8px;
  background: var(--accent-soft);
}

@media (max-width: 640px) {
  .index-header {
    padding: 22px;
  }

  .document {
    padding: 18px;
  }
}