:root {
  --bg: #f6f7f9;
  --card: #ffffff;
  --text: #24292f;
  --muted: #6b7280;
  --border: #e5e7eb;
  --primary: #2563eb;
  --primary-light: #eff6ff;
  --radius: 12px;
  --shadow: 0 1px 3px rgba(0,0,0,.06), 0 1px 2px rgba(0,0,0,.04);
  --shadow-hover: 0 8px 24px rgba(0,0,0,.10);
}
* { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; }
body {
  font-family: -apple-system, BlinkMacSystemFont, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.6;
}
.container { max-width: 1080px; margin: 0 auto; padding: 0 20px; }
a { color: var(--primary); text-decoration: none; }
a:hover { text-decoration: underline; }

/* ---------- 随机背景图层 ---------- */
#bgLayer {
  position: fixed; inset: 0; z-index: -2;
  background-position: center; background-size: cover; background-repeat: no-repeat;
  opacity: 0; transition: opacity .8s ease;
}
#bgLayer.loaded { opacity: 1; }
#bgLayer::after {
  content: ''; position: absolute; inset: 0;
  background: linear-gradient(180deg, rgba(247,248,250,.0), rgba(247,248,250,.60));
}

/* ---------- 头部 ---------- */
.site-header {
  position: sticky; top: 0; z-index: 100;
  background: rgba(255,255,255,.92);
  backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--border);
}
.header-inner { display: flex; align-items: center; gap: 20px; height: 64px; }
.logo { display: flex; align-items: center; gap: 10px; color: var(--text); flex-shrink: 0; }
.logo:hover { text-decoration: none; }
.logo-mark {
  display: block;
  width: 38px; height: 38px; border-radius: 10px;
  object-fit: cover;
  box-shadow: 0 1px 4px rgba(0,0,0,.15);
}
.logo-text { font-weight: 700; font-size: 18px; letter-spacing: .5px; display: flex; flex-direction: column; line-height: 1.2; }
.logo-sub { font-size: 11px; font-weight: 400; color: var(--muted); letter-spacing: 0; }
.search-box {
  flex: 1; max-width: 420px; display: flex; align-items: center; gap: 8px;
  background: var(--bg); border: 1px solid var(--border); border-radius: 999px;
  padding: 8px 16px; color: var(--muted); transition: border-color .2s;
}
.search-box:focus-within { border-color: var(--primary); }
.search-box input { flex: 1; border: none; outline: none; background: transparent; font-size: 14px; color: var(--text); }
.header-stats { margin-left: auto; font-size: 13px; color: var(--muted); white-space: nowrap; }
.header-stats b { color: var(--primary); }

/* ---------- 分类 chips ---------- */
.cat-bar { display: flex; flex-wrap: wrap; gap: 8px; padding: 20px 0 4px; }
.chip {
  padding: 6px 14px; border-radius: 999px; font-size: 13px; cursor: pointer;
  background: var(--card); border: 1px solid var(--border); color: var(--muted);
  transition: all .15s; user-select: none;
}
.chip:hover { border-color: var(--primary); color: var(--primary); }
.chip.active { background: var(--primary); border-color: var(--primary); color: #fff; }
.chip .cnt { opacity: .7; font-size: 12px; margin-left: 2px; }

/* ---------- 文章卡片 ---------- */
.list-head { display: flex; align-items: baseline; gap: 10px; margin: 20px 0 14px; }
.list-head h2 { font-size: 20px; text-shadow: 0 1px 4px rgba(255,255,255,.95), 0 0 12px rgba(255,255,255,.8); }
.list-head span { font-size: 13px; color: #374151; font-weight: 500; text-shadow: 0 1px 3px rgba(255,255,255,.95), 0 0 8px rgba(255,255,255,.85); }
.grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(300px, 1fr)); gap: 18px; }
.card {
  background: var(--card); border: 1px solid var(--border); border-radius: var(--radius);
  overflow: hidden; cursor: pointer; display: flex; flex-direction: column;
  transition: transform .18s, box-shadow .18s;
}
.card:hover { transform: translateY(-3px); box-shadow: var(--shadow-hover); }
.card-cover { height: 150px; position: relative; overflow: hidden; background: #e9ecf1; }
.card-cover img {
  width: 100%; height: 100%; object-fit: cover; display: block;
  transition: transform .35s ease;
}
.card:hover .card-cover img { transform: scale(1.05); }
.card-cover .cat-badge {
  position: absolute; top: 10px; left: 10px; z-index: 1;
  background: rgba(0,0,0,.55); color: #fff; font-size: 12px;
  padding: 3px 10px; border-radius: 999px; backdrop-filter: blur(4px);
}
.card-body { padding: 14px 16px 16px; display: flex; flex-direction: column; flex: 1; }
.card-title {
  font-size: 15px; font-weight: 600; line-height: 1.45; color: var(--text);
  display: -webkit-box; -webkit-line-clamp: 2; -webkit-box-orient: vertical; overflow: hidden;
}
.card:hover .card-title { color: var(--primary); }
.card-excerpt {
  margin-top: 8px; font-size: 13px; color: var(--muted); flex: 1;
  display: -webkit-box; -webkit-line-clamp: 2; -webkit-box-orient: vertical; overflow: hidden;
}
.card-meta { margin-top: 12px; font-size: 12px; color: #9ca3af; display: flex; justify-content: space-between; align-items: center; }

.empty { text-align: center; padding: 60px 0; color: var(--muted); }
.load-more {
  display: block; margin: 26px auto; padding: 10px 32px;
  background: var(--card); border: 1px solid var(--border); border-radius: 999px;
  color: var(--muted); font-size: 14px; cursor: pointer; transition: all .15s;
}
.load-more:hover { border-color: var(--primary); color: var(--primary); }

/* ---------- 文章详情 ---------- */
.article-wrap { max-width: 820px; margin: 24px auto 40px; background: var(--card); border: 1px solid var(--border); border-radius: var(--radius); padding: 32px 40px 48px; }
.back-link { display: inline-flex; align-items: center; gap: 4px; font-size: 14px; margin-bottom: 18px; }
.article-cover { width: 100%; max-height: 320px; object-fit: cover; border-radius: 10px; margin-bottom: 22px; }
.article-title { font-size: 28px; line-height: 1.35; margin-bottom: 14px; }
.article-meta { display: flex; flex-wrap: wrap; gap: 14px; font-size: 13px; color: var(--muted); padding-bottom: 20px; border-bottom: 1px solid var(--border); margin-bottom: 26px; }
.article-meta .cat-badge2 { background: var(--primary-light); color: var(--primary); padding: 2px 12px; border-radius: 999px; }

/* markdown 正文排版 */
.md { font-size: 15.5px; line-height: 1.85; word-break: break-word; }
.md h1, .md h2, .md h3, .md h4 { margin: 1.6em 0 .6em; line-height: 1.4; }
.md h1 { font-size: 24px; } .md h2 { font-size: 20px; border-left: 4px solid var(--primary); padding-left: 12px; }
.md h3 { font-size: 17px; } .md h4 { font-size: 15.5px; }
.md p { margin: .8em 0; }
.md ul, .md ol { padding-left: 1.6em; margin: .8em 0; }
.md li { margin: .3em 0; }
.md blockquote { margin: 1em 0; padding: 8px 16px; border-left: 4px solid #d1d5db; background: var(--bg); color: var(--muted); border-radius: 0 8px 8px 0; }
.md blockquote p { margin: .3em 0; }
.md code { background: #f0f1f3; padding: 2px 6px; border-radius: 4px; font-size: .88em; font-family: "SF Mono", Menlo, Consolas, monospace; }
.md pre { background: #f6f8fa; border: 1px solid var(--border); border-radius: 10px; padding: 16px; overflow-x: auto; margin: 1em 0; }
.md pre code { background: transparent; padding: 0; font-size: 13.5px; line-height: 1.6; }
.md img { max-width: 100%; border-radius: 8px; }
.md img.img-broken {
  display: block; width: 100%; max-width: 520px; margin: 1.2em auto;
  border: 1px solid var(--border); background: #f7f9fc;
}
.md table { border-collapse: collapse; width: 100%; margin: 1em 0; font-size: 14px; }
.md th, .md td { border: 1px solid var(--border); padding: 8px 12px; text-align: left; }
.md th { background: var(--bg); }
.md hr { border: none; border-top: 1px solid var(--border); margin: 2em 0; }
.md a { word-break: break-all; }

/* 上下篇 */
.article-nav { display: flex; justify-content: space-between; gap: 16px; margin-top: 36px; padding-top: 20px; border-top: 1px solid var(--border); }
.article-nav a { font-size: 14px; max-width: 48%; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }

/* ---------- 页脚 / 其他 ---------- */
.site-footer { /*border-top: 1px solid var(--border);*/ padding: 30px 0 40px; text-align: center; font-size: 14px; color: var(--muted); margin-top: 40px; }
.site-footer .muted { font-size: 12.5px; margin-top: 4px; }
.site-footer .muted a { color: var(--muted); }
#backTop {
  position: fixed; right: 24px; bottom: 32px; width: 42px; height: 42px;
  border-radius: 50%; border: 1px solid var(--border); background: var(--card);
  color: var(--muted); font-size: 18px; cursor: pointer; box-shadow: var(--shadow);
  opacity: 0; pointer-events: none; transition: opacity .2s;
}
#backTop.show { opacity: 1; pointer-events: auto; }
#backTop:hover { color: var(--primary); border-color: var(--primary); }

@media (max-width: 720px) {
  .header-inner { flex-wrap: wrap; height: auto; padding: 10px; }
  .header-stats { display: none; }
  .article-wrap { padding: 20px; margin: 16px auto; }
  .article-title { font-size: 22px; }
}