:root {
  --article-max: 1120px;
}

* { box-sizing: border-box; }

body {
  margin: 0;
  min-height: 100vh;
  background: var(--bg, #f6f8fa);
  color: var(--text, #1f2328);
  font-family: 'Microsoft YaHei','PingFang SC','Segoe UI',Arial,sans-serif;
}

a { color: inherit; }

.site-header {
  position: sticky;
  top: 0;
  z-index: 20;
  background: color-mix(in srgb, var(--card, #fff) 92%, transparent);
  border-bottom: 1px solid var(--border, #d0d7de);
  backdrop-filter: blur(14px);
}

.site-header .inner {
  max-width: var(--article-max);
  min-height: 64px;
  margin: 0 auto;
  padding: 10px 20px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 18px;
}

.logo {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  color: var(--hero-text, var(--text, #1f2328));
  font-size: 20px;
  font-weight: 800;
  text-decoration: none;
  white-space: nowrap;
}

.logo-mark {
  width: 28px;
  height: 28px;
  border-radius: 9px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  background: var(--primary, #0969da);
  color: #fff;
  font-size: 14px;
}

.site-nav {
  display: flex;
  align-items: center;
  justify-content: flex-end;
  gap: 8px;
  flex-wrap: wrap;
}

.site-nav a {
  padding: 8px 12px;
  border-radius: 8px;
  color: var(--text2, #656d76);
  text-decoration: none;
  font-size: 14px;
  font-weight: 700;
}

.site-nav a:hover,
.site-nav a.active {
  color: var(--primary, #0969da);
  background: var(--hover, #f3f4f6);
}

.article-hero {
  background: var(--hero-bg, linear-gradient(135deg,#f6f8fa,#fff));
  border-bottom: 1px solid var(--border, #d0d7de);
}

.article-hero .inner {
  max-width: var(--article-max);
  margin: 0 auto;
  padding: 42px 20px 38px;
}

.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 5px 10px;
  border: 1px solid color-mix(in srgb, var(--primary, #0969da) 42%, transparent);
  border-radius: 999px;
  color: var(--primary, #0969da);
  background: var(--badge-bg, rgba(9,105,218,.1));
  font-size: 12px;
  font-weight: 800;
}

h1 {
  margin: 14px 0 12px;
  color: var(--hero-text, var(--text, #1f2328));
  font-size: 34px;
  line-height: 1.22;
  letter-spacing: 0;
}

.lead {
  max-width: 760px;
  margin: 0;
  color: var(--text2, #656d76);
  font-size: 16px;
  line-height: 1.9;
}

.article-wrap {
  max-width: var(--article-max);
  margin: 0 auto;
  padding: 28px 20px 46px;
}

.article-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 16px;
}

.article-card {
  min-height: 220px;
  padding: 20px;
  border: 1px solid var(--border, #d0d7de);
  border-radius: 8px;
  background: var(--card, #fff);
  text-decoration: none;
  display: flex;
  flex-direction: column;
  gap: 12px;
  transition: .18s ease;
}

.article-card:hover {
  border-color: var(--primary, #0969da);
  transform: translateY(-2px);
}

.article-card .tag {
  width: fit-content;
  padding: 4px 9px;
  border-radius: 999px;
  background: var(--badge-bg, rgba(9,105,218,.1));
  color: var(--primary, #0969da);
  font-size: 12px;
  font-weight: 800;
}

.article-card h2 {
  margin: 0;
  color: var(--text, #1f2328);
  font-size: 19px;
  line-height: 1.45;
}

.article-card p {
  margin: 0;
  color: var(--text2, #656d76);
  font-size: 14px;
  line-height: 1.8;
}

.article-layout {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 280px;
  gap: 24px;
  align-items: start;
}

.article-content {
  padding: 28px;
  border: 1px solid var(--border, #d0d7de);
  border-radius: 8px;
  background: var(--card, #fff);
}

.article-content h2 {
  margin: 30px 0 12px;
  color: var(--text, #1f2328);
  font-size: 22px;
  line-height: 1.45;
}

.article-content h2:first-child { margin-top: 0; }

.article-content p,
.article-content li {
  color: var(--text2, #656d76);
  font-size: 15px;
  line-height: 2;
}

.article-content p { margin: 0 0 14px; }
.article-content ul { margin: 0 0 16px; padding-left: 20px; }

.topic-cover {
  margin: 0 0 22px;
  border: 1px solid var(--border, #d0d7de);
  border-radius: 10px;
  overflow: hidden;
  background: var(--input-bg, #f6f8fa);
}

.topic-cover img {
  display: block;
  width: 100%;
  max-height: 360px;
  object-fit: cover;
}

.topic-card-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 12px;
  margin: 18px 0;
}

.topic-card-grid a {
  display: block;
  padding: 13px 14px;
  border: 1px solid var(--border, #d0d7de);
  border-radius: 8px;
  background: color-mix(in srgb, var(--card, #fff) 90%, var(--hover, #f3f4f6));
  color: var(--primary, #0969da);
  text-decoration: none;
  font-weight: 800;
}

.topic-card-grid a:hover { border-color: var(--primary, #0969da); }

.note-box {
  margin: 22px 0;
  padding: 16px 18px;
  border: 1px solid color-mix(in srgb, var(--primary, #0969da) 32%, var(--border, #d0d7de));
  border-radius: 8px;
  background: var(--badge-bg, rgba(9,105,218,.1));
  color: var(--text, #1f2328);
  line-height: 1.9;
}

.side-box {
  position: sticky;
  top: 88px;
  padding: 18px;
  border: 1px solid var(--border, #d0d7de);
  border-radius: 8px;
  background: var(--card, #fff);
}

.side-box h3 {
  margin: 0 0 12px;
  font-size: 16px;
}

.side-box a {
  display: block;
  padding: 9px 0;
  border-top: 1px solid var(--border, #d0d7de);
  color: var(--text2, #656d76);
  text-decoration: none;
  font-size: 14px;
  line-height: 1.5;
}

.side-box a:hover { color: var(--primary, #0969da); }

.cta-row {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-top: 24px;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 40px;
  padding: 0 16px;
  border-radius: 8px;
  border: 1px solid var(--primary, #0969da);
  text-decoration: none;
  font-weight: 800;
  font-size: 14px;
}

.btn-primary {
  background: var(--primary, #0969da);
  color: #fff;
}

.btn-outline {
  color: var(--primary, #0969da);
  background: transparent;
}

.site-footer {
  border-top: 1px solid var(--border, #d0d7de);
  background: var(--footer-bg, var(--card, #fff));
}

.site-footer .inner {
  max-width: var(--article-max);
  margin: 0 auto;
  padding: 24px 20px;
  color: var(--text2, #656d76);
  font-size: 13px;
  line-height: 1.8;
}

@media (max-width: 860px) {
  .site-header .inner { align-items: flex-start; flex-direction: column; }
  .site-nav { justify-content: flex-start; }
  h1 { font-size: 28px; }
  .article-grid { grid-template-columns: 1fr; }
  .article-layout { grid-template-columns: 1fr; }
  .side-box { position: static; }
  .article-content { padding: 22px; }
  .topic-card-grid { grid-template-columns: 1fr; }
}