:root {
  --bg: #0b0f1a;
  --panel: #141a2b;
  --card: #1a2236;
  --border: #27324d;
  --text: #e6ebf5;
  --muted: #93a0bd;
  --accent: #6c8cff;
  --accent2: #34d399;
  --warn: #fbbf24;
}
* { box-sizing: border-box; margin: 0; padding: 0; }
body {
  background: var(--bg);
  color: var(--text);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Microsoft YaHei", sans-serif;
  line-height: 1.75;
  -webkit-font-smoothing: antialiased;
}
a { color: inherit; text-decoration: none; }
.wrap { max-width: 1100px; margin: 0 auto; padding: 32px 20px 80px; }
.wrap.narrow { max-width: 860px; }

/* 顶部导航 */
.topnav {
  position: sticky;
  top: 0;
  z-index: 50;
  background: rgba(11,15,26,.92);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--border);
}
.topnav-inner {
  max-width: 1100px;
  margin: 0 auto;
  padding: 14px 22px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 18px;
  flex-wrap: wrap;
}
.brand { display: flex; align-items: baseline; gap: 10px; }
.brand .logo { font-size: 20px; font-weight: 800; color: #fff; letter-spacing: .5px; }
.brand .slogan { color: var(--muted); font-size: 13px; }
.nav-links { display: flex; gap: 4px; flex-wrap: wrap; }
.nav-links a {
  color: var(--text);
  font-size: 14.5px;
  font-weight: 600;
  padding: 7px 14px;
  border-radius: 8px;
  transition: background .15s ease, color .15s ease;
}
.nav-links a:hover { background: var(--card); color: #fff; }
.nav-links a.active { color: var(--accent2); }

/* Hero / 页头 */
header.hero {
  background: linear-gradient(160deg, #131a30 0%, #0b0f1a 60%);
  border: 1px solid var(--border);
  border-radius: 18px;
  padding: 40px 34px;
  margin-bottom: 26px;
}
.tag {
  display: inline-block;
  font-size: 12px;
  font-weight: 600;
  letter-spacing: .5px;
  color: var(--accent2);
  background: rgba(52,211,153,.12);
  border: 1px solid rgba(52,211,153,.35);
  padding: 4px 12px;
  border-radius: 999px;
  margin-bottom: 16px;
}
h1 { font-size: 30px; line-height: 1.35; font-weight: 800; letter-spacing: .3px; }
.subtitle { color: var(--muted); font-size: 15px; margin-top: 12px; }

/* 区块与卡片 */
section { margin-bottom: 30px; }
.card {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 14px;
  padding: 24px 26px;
}
h2 {
  font-size: 20px;
  font-weight: 700;
  margin-bottom: 14px;
  padding-left: 12px;
  border-left: 4px solid var(--accent);
}
h3 { font-size: 16px; font-weight: 700; margin: 14px 0 8px; color: var(--accent); }
p { margin: 8px 0; }
ul, ol { margin: 8px 0 8px 4px; padding-left: 22px; }
li { margin: 7px 0; }
li b, p b { color: #fff; }
.muted { color: var(--muted); }

/* 分类标题（工具页） */
.cat-title {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 18px;
  font-weight: 700;
  margin: 34px 0 16px;
  color: #fff;
}
.cat-title .num {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 26px;
  height: 26px;
  border-radius: 8px;
  background: linear-gradient(135deg, #6c8cff, #4f6ef2);
  color: #fff;
  font-size: 14px;
  font-weight: 800;
}

/* 卡片网格 */
.grid { display: grid; gap: 16px; }
.grid-2 { grid-template-columns: repeat(2, 1fr); }
.grid-3 { grid-template-columns: repeat(3, 1fr); }
@media (max-width: 800px) { .grid-2, .grid-3 { grid-template-columns: 1fr; } }

/* 图片卡片（顶部大图 + 底部文字） */
.img-card {
  display: block;
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 14px;
  overflow: hidden;
  transition: border-color .15s ease, transform .15s ease;
}
.img-card:hover { border-color: var(--accent); transform: translateY(-2px); }
.img-card-img {
  height: 160px;
  background-size: cover;
  background-position: center;
  border-bottom: 1px solid var(--border);
}
.img-card-body { padding: 18px 20px; }
.img-card-body h3 { margin: 0 0 6px; font-size: 16px; color: #fff; }
.img-card-body p { color: var(--muted); font-size: 13.5px; margin: 0 0 10px; }
.img-card-body .go { color: var(--accent); font-size: 13px; font-weight: 600; }

/* 精选项目大图卡 */
.feature-img { height: 210px; }

/* 工具卡片 */
.tool-card {
  display: flex;
  gap: 14px;
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 14px;
  padding: 18px 20px;
  transition: border-color .15s ease, transform .15s ease;
}
.tool-card:hover { border-color: var(--accent); transform: translateY(-2px); }
.tool-card .icon {
  flex: 0 0 auto;
  width: 44px;
  height: 44px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 22px;
  border-radius: 12px;
  background: var(--panel);
  border: 1px solid var(--border);
}
.tool-card .info { min-width: 0; }
.tool-card .t-name { font-weight: 700; color: #fff; font-size: 15px; }
.tool-card .t-desc { color: var(--muted); font-size: 13.5px; margin-top: 4px; }
.tool-card .t-link { display: inline-block; color: var(--accent); font-size: 12.5px; margin-top: 8px; }
.tool-card .t-link:hover { text-decoration: underline; }

/* QQ 群横幅 */
.qq-banner {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  flex-wrap: wrap;
  background: linear-gradient(135deg, #fbbf24, #f59e0b);
  color: #1a1204;
  font-weight: 700;
  font-size: 15px;
  padding: 12px 20px;
  border-radius: 12px;
  margin-bottom: 18px;
  text-align: center;
}
.qq-banner .qq-num {
  font-size: 19px;
  font-weight: 800;
  letter-spacing: 1px;
  background: rgba(255,255,255,.35);
  padding: 2px 12px;
  border-radius: 8px;
}
.qq-banner a { color: #1a1204; text-decoration: underline; }

/* 架构网格 */
.arch {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 14px;
  margin-top: 14px;
}
.arch .item {
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 16px 18px;
}
.arch .item .name { font-weight: 700; color: var(--accent); margin-bottom: 6px; }
.arch .item .desc { color: var(--muted); font-size: 13.5px; }

/* 标签 pill */
.meta { display: flex; flex-wrap: wrap; gap: 10px; margin-top: 16px; }
.pill {
  font-size: 13px;
  color: var(--text);
  background: var(--panel);
  border: 1px solid var(--border);
  padding: 6px 14px;
  border-radius: 999px;
}
.pill b { color: var(--warn); }

/* 视频容器 */
.video-box {
  background: #000;
  border: 1px solid var(--border);
  border-radius: 14px;
  overflow: hidden;
  margin-top: 6px;
}
.video-box video {
  width: 100%;
  display: block;
  max-height: 520px;
}

/* 提示框 */
.note {
  background: rgba(251,191,36,.08);
  border: 1px solid rgba(251,191,36,.3);
  border-radius: 12px;
  padding: 14px 18px;
  margin: 16px 0;
  font-size: 14px;
  color: var(--text);
}
.note b { color: var(--warn); }

/* 文章列表 */
.article-card {
  display: block;
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 14px;
  padding: 22px 24px;
  margin-bottom: 16px;
  transition: border-color .15s ease, transform .15s ease;
}
.article-card:hover { border-color: var(--accent); transform: translateY(-2px); }
.article-card .a-title { font-size: 18px; font-weight: 700; color: #fff; }
.article-card .a-desc { color: var(--muted); font-size: 14px; margin-top: 8px; }
.article-card .a-more { color: var(--accent); font-size: 13px; margin-top: 12px; display: inline-block; }

/* 文章正文 */
.article-body p { margin: 14px 0; }
.article-body h3 { margin-top: 26px; }
.article-body .lead { font-size: 16px; color: var(--text); }
.divider { height: 1px; background: var(--border); margin: 34px 0; }

/* 按钮 */
.cta {
  display: inline-block;
  margin-top: 20px;
  font-weight: 700;
  font-size: 15px;
  color: #fff;
  background: linear-gradient(135deg, #6c8cff, #4f6ef2);
  padding: 13px 26px;
  border-radius: 12px;
  transition: transform .15s ease, box-shadow .15s ease;
}
.cta:hover { transform: translateY(-2px); box-shadow: 0 8px 24px rgba(108,140,255,.35); }

/* 页脚 */
.foot { text-align: center; color: var(--muted); font-size: 13px; margin-top: 40px; }
.foot .link { color: var(--accent); }
.link { word-break: break-all; color: var(--accent); font-size: 13px; }