:root {
  --bg: #f5f7fa;
  --surface: #ffffff;
  --surface2: #eef2f7;
  --text: #1a2332;
  --muted: #5c6b7e;
  --accent: #2563eb;
  --accent-hover: #1d4ed8;
  --border: #dce3ed;
  --radius: 12px;
  --font: "SF Pro Text", "PingFang SC", "Microsoft YaHei", system-ui, sans-serif;
}

*,
*::before,
*::after {
  box-sizing: border-box;
}

html {
  font-size: 16px;
  -webkit-font-smoothing: antialiased;
}

body {
  margin: 0;
  min-height: 100vh;
  font-family: var(--font);
  background: var(--bg);
  color: var(--text);
  line-height: 1.5;
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 10;
  background: rgba(255, 255, 255, 0.95);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--border);
  box-shadow: 0 1px 0 rgba(0, 0, 0, 0.04);
}

.header-inner {
  max-width: 1100px;
  margin: 0 auto;
  padding: 1rem 1.25rem;
  display: flex;
  align-items: center;
  gap: 1rem;
  flex-wrap: wrap;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  font-size: 1.25rem;
  font-weight: 600;
  color: var(--text);
  text-decoration: none;
  letter-spacing: 0.02em;
}

.site-logo {
  height: 1.75rem;
  width: auto;
  max-height: 32px;
  max-width: 2.75rem;
  object-fit: contain;
  flex-shrink: 0;
  display: block;
}

.brand-text {
  line-height: 1.25;
}

.brand:hover {
  color: var(--accent);
}

.brand:hover .site-logo {
  opacity: 0.92;
}

.meta-count {
  font-size: 0.85rem;
  color: var(--muted);
}

.breadcrumb {
  max-width: 1100px;
  margin: 0 auto;
  padding: 0 1.25rem 0.75rem;
  font-size: 0.9rem;
  color: var(--muted);
  display: flex;
  flex-wrap: wrap;
  gap: 0.35rem;
  align-items: center;
}

.breadcrumb a {
  color: var(--accent);
  text-decoration: none;
}

.breadcrumb a:hover {
  text-decoration: underline;
}

.breadcrumb span.sep {
  opacity: 0.5;
}

.main {
  max-width: 1100px;
  margin: 0 auto;
  padding: 1.5rem 1.25rem 3rem;
}

.page-title {
  font-size: 1.35rem;
  font-weight: 600;
  margin: 0 0 0.5rem;
}

.page-desc {
  color: var(--muted);
  margin: 0 0 1.5rem;
  font-size: 0.95rem;
}

.page-desc code {
  font-size: 0.9em;
  background: var(--surface2);
  padding: 0.1rem 0.35rem;
  border-radius: 4px;
}

.static-back {
  margin: 0 0 1rem;
}

.static-back a {
  color: var(--accent);
  text-decoration: none;
}

.static-back a:hover {
  text-decoration: underline;
}

.grid-cards {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
  gap: 1rem;
}

.grid-cards-topics {
  margin-top: 0.25rem;
}

.home-divider {
  border: none;
  border-top: 1px solid var(--border);
  margin: 2.25rem 0 1.5rem;
}

.home-section-title {
  font-size: 1.15rem;
  font-weight: 600;
  margin: 0 0 0.35rem;
  color: var(--text);
}

.home-section-desc {
  margin: 0 0 1.25rem;
  font-size: 0.92rem;
  color: var(--muted);
}

.card {
  display: block;
  padding: 1.25rem;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  text-decoration: none;
  color: inherit;
  box-shadow: 0 1px 2px rgba(15, 23, 42, 0.06);
  transition: border-color 0.15s, box-shadow 0.15s, transform 0.15s;
}

.card:hover {
  border-color: #c5d4e8;
  box-shadow: 0 4px 12px rgba(15, 23, 42, 0.08);
  transform: translateY(-2px);
}

.card h2 {
  margin: 0 0 0.5rem;
  font-size: 1.1rem;
  font-weight: 600;
  color: var(--accent);
}

.card p {
  margin: 0;
  font-size: 0.88rem;
  color: var(--muted);
}

.card .badge {
  display: inline-block;
  margin-top: 0.75rem;
  font-size: 0.8rem;
  color: var(--text);
  background: var(--surface2);
  padding: 0.2rem 0.55rem;
  border-radius: 6px;
}

.list-panel {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  overflow: hidden;
  box-shadow: 0 1px 2px rgba(15, 23, 42, 0.04);
}

.list-panel ul {
  list-style: none;
  margin: 0;
  padding: 0;
}

.list-panel li {
  border-bottom: 1px solid var(--border);
}

.list-panel li:last-child {
  border-bottom: none;
}

.list-panel a {
  display: block;
  padding: 0.85rem 1rem;
  color: var(--text);
  text-decoration: none;
  font-size: 0.92rem;
  line-height: 1.45;
}

.list-panel a:hover {
  background: var(--surface2);
  color: var(--accent);
}

.subgrid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
  gap: 0.75rem;
}

.subcard {
  display: block;
  padding: 1rem;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  text-align: center;
  text-decoration: none;
  color: var(--accent);
  font-weight: 500;
  transition: background 0.15s, border-color 0.15s;
  box-shadow: 0 1px 2px rgba(15, 23, 42, 0.04);
}

.subcard:hover {
  background: var(--surface2);
  border-color: #c5d4e8;
}

.subcard small {
  display: block;
  margin-top: 0.35rem;
  font-weight: 400;
  color: var(--muted);
  font-size: 0.8rem;
}

.site-footer {
  max-width: 1100px;
  margin: 0 auto;
  padding: 1rem 1.25rem 2rem;
  font-size: 0.8rem;
  color: var(--muted);
}

.site-footer code {
  font-size: 0.85em;
  background: var(--surface2);
  padding: 0.1rem 0.35rem;
  border-radius: 4px;
}

.empty {
  color: var(--muted);
  padding: 2rem;
  text-align: center;
}

.submit-strip {
  max-width: 1100px;
  margin: 0 auto 2.5rem;
  padding: 1.5rem 1.25rem 2rem;
  text-align: center;
  border-top: 1px solid var(--border);
  background: linear-gradient(180deg, var(--bg) 0%, #eef2f7 100%);
}

.submit-strip--top {
  max-width: none;
  margin: 0 0 1.25rem;
  padding: 0 0 0.25rem;
  border-top: none;
  background: transparent;
  text-align: left;
}

.submit-strip-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
  align-items: center;
}

.btn-submit {
  display: inline-block;
  padding: 0.85rem 2.25rem;
  font-size: 1.05rem;
  font-weight: 600;
  color: #fff;
  background: var(--accent);
  border: none;
  border-radius: 12px;
  text-decoration: none;
  box-shadow: 0 4px 14px rgba(37, 99, 235, 0.4);
  transition: background 0.15s, transform 0.12s, box-shadow 0.15s;
}

.btn-submit:hover {
  background: var(--accent-hover);
  transform: translateY(-1px);
  box-shadow: 0 6px 18px rgba(37, 99, 235, 0.45);
}

.btn-submit--secondary {
  color: var(--accent);
  background: var(--surface);
  border: 1px solid var(--border);
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.06);
}

.btn-submit--secondary:hover {
  background: var(--surface2);
  border-color: #c5d0e0;
  box-shadow: 0 4px 12px rgba(37, 99, 235, 0.12);
}

.main--about {
  max-width: 42rem;
  margin-left: auto;
  margin-right: auto;
}

.about-article {
  margin: 0.25rem 0 0;
  padding: 2rem 1.75rem 2.25rem;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  box-shadow: 0 2px 12px rgba(0, 0, 0, 0.05);
}

.about-article .page-title {
  text-align: center;
  margin-bottom: 1.35rem;
}

.about-body {
  margin: 0;
  font-size: 1.05rem;
  line-height: 1.85;
  color: var(--text);
  text-align: justify;
  text-justify: inter-ideographic;
}

.about-contact {
  margin-top: 1.75rem;
  padding-top: 1.5rem;
  border-top: 1px solid var(--border);
  text-align: center;
}

.about-contact-note {
  margin: 0 0 1.25rem;
  font-size: 1.02rem;
  line-height: 1.75;
  color: var(--text);
  text-align: justify;
  text-justify: inter-ideographic;
}

.about-qrcode {
  display: block;
  width: min(220px, 72vw);
  height: auto;
  margin: 0 auto;
  border-radius: 12px;
  box-shadow: 0 4px 16px rgba(0, 0, 0, 0.08);
}