/* ============================================================
   Atom 门户 · 公共样式（mdview 风格：简洁、卡片、蓝白配色）
   ============================================================ */
:root {
  --primary: #2563eb;
  --primary-dark: #1d4ed8;
  --primary-soft: #eff6ff;
  --text: #111827;
  --text-2: #374151;
  --muted: #6b7280;
  --bg: #ffffff;
  --bg-soft: #f7f8fa;
  --border: #e5e7eb;
  --radius: 14px;
  --shadow: 0 1px 2px rgba(17, 24, 39, .05), 0 8px 24px rgba(17, 24, 39, .06);
}

* { margin: 0; padding: 0; box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC",
    "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  font-size: 16px;
  line-height: 1.7;
  color: var(--text);
  background: var(--bg);
}
a { color: var(--primary); text-decoration: none; }
a:hover { color: var(--primary-dark); }
.container { max-width: 1080px; margin: 0 auto; padding: 0 24px; }

/* ---------- 顶部公告条 ---------- */
.topbar {
  display: block;
  text-align: center;
  padding: 9px 16px;
  font-size: 14px;
  color: #fff;
  background: linear-gradient(90deg, #2563eb, #4f8cff);
}
.topbar:hover { color: #fff; opacity: .95; }
.topbar strong { font-weight: 700; }

/* ---------- 头部导航（大栏目按钮） ---------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  background: rgba(255, 255, 255, .92);
  backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--border);
}
.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  height: 64px;
}
.logo {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 18px;
  font-weight: 800;
  color: var(--text);
}
.logo:hover { color: var(--text); }
.logo-mark {
  width: 32px;
  height: 32px;
  border-radius: 9px;
  background: var(--primary);
  color: #fff;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  font-size: 17px;
  font-weight: 800;
}
.site-nav { display: flex; gap: 8px; flex-wrap: wrap; }
.nav-btn {
  padding: 10px 18px;
  border-radius: 10px;
  font-size: 15px;
  font-weight: 600;
  color: var(--text-2);
}
.nav-btn:hover { background: var(--bg-soft); color: var(--primary); }
.nav-btn.active { background: var(--primary-soft); color: var(--primary); }

/* ---------- 按钮 ---------- */
.btn {
  display: inline-block;
  padding: 14px 30px;
  border-radius: 12px;
  border: 1px solid transparent;
  font-size: 16px;
  font-weight: 700;
  cursor: pointer;
}
.btn:hover { color: #fff; }
.btn-primary { background: var(--primary); color: #fff; box-shadow: var(--shadow); }
.btn-primary:hover { background: var(--primary-dark); }
.btn-ghost { background: #fff; border-color: var(--border); color: var(--text); }
.btn-ghost:hover { border-color: var(--primary); color: var(--primary); background: var(--primary-soft); }

/* ---------- 首页 Hero ---------- */
.hero {
  padding: 80px 0 48px;
  text-align: center;
  background: linear-gradient(180deg, var(--primary-soft) 0%, #fff 100%);
}
.hero h1 { font-size: 46px; font-weight: 800; line-height: 1.2; letter-spacing: -.5px; }
.hero .lead { max-width: 720px; margin: 20px auto 0; font-size: 17px; color: var(--muted); }
.hero-links { margin-top: 22px; font-size: 15px; color: var(--muted); }
.hero-cta { margin-top: 32px; display: flex; gap: 14px; justify-content: center; flex-wrap: wrap; }
.stats { margin-top: 40px; display: flex; gap: 12px; justify-content: center; flex-wrap: wrap; }
.stat {
  padding: 14px 26px;
  background: #fff;
  border: 1px solid var(--border);
  border-radius: 12px;
  box-shadow: var(--shadow);
}
.stat b { display: block; font-size: 22px; }
.stat span { font-size: 13px; color: var(--muted); }

/* ---------- 内页 Hero ---------- */
.page-hero {
  padding: 56px 0 40px;
  text-align: center;
  background: linear-gradient(180deg, var(--primary-soft), #fff);
}
.page-hero h1 { font-size: 34px; font-weight: 800; }
.page-hero p { max-width: 640px; margin: 12px auto 0; color: var(--muted); }

/* ---------- 通用 Section ---------- */
.section { padding: 72px 0; }
.section.soft { background: var(--bg-soft); }
.section-head { max-width: 640px; margin: 0 auto 44px; text-align: center; }
.eyebrow { display: inline-block; margin-bottom: 10px; font-size: 14px; font-weight: 700; color: var(--primary); }
.section-head h2 { font-size: 32px; font-weight: 800; }
.section-head p { margin-top: 12px; color: var(--muted); }

/* ---------- 栏目大按钮 / 卡片 ---------- */
.section-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 18px; }
.section-card {
  display: block;
  padding: 26px;
  background: #fff;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  transition: transform .15s ease, border-color .15s ease;
}
.section-card:hover { transform: translateY(-3px); border-color: var(--primary); color: var(--text); }
.card-icon {
  width: 48px;
  height: 48px;
  border-radius: 12px;
  background: var(--primary-soft);
  font-size: 24px;
  display: flex;
  align-items: center;
  justify-content: center;
}
.section-card h3 { margin-top: 16px; font-size: 19px; font-weight: 700; }
.section-card p { margin-top: 8px; font-size: 14px; color: var(--muted); }
.card-go { display: inline-block; margin-top: 14px; font-size: 14px; font-weight: 600; color: var(--primary); }

/* ---------- 步骤 ---------- */
.steps { display: grid; grid-template-columns: repeat(3, 1fr); gap: 18px; }
.step { padding: 26px; background: #fff; border: 1px solid var(--border); border-radius: var(--radius); }
.step-num {
  width: 34px;
  height: 34px;
  border-radius: 50%;
  background: var(--primary);
  color: #fff;
  font-weight: 800;
  display: flex;
  align-items: center;
  justify-content: center;
}
.step h3 { margin-top: 14px; font-size: 17px; }
.step p { margin-top: 8px; font-size: 14px; color: var(--muted); }

/* ---------- FAQ 手风琴 ---------- */
.faq-list { max-width: 760px; margin: 0 auto; }
.faq-item {
  margin-bottom: 12px;
  background: #fff;
  border: 1px solid var(--border);
  border-radius: 12px;
  overflow: hidden;
}
.faq-item summary {
  position: relative;
  padding: 18px 48px 18px 22px;
  font-weight: 600;
  cursor: pointer;
  list-style: none;
}
.faq-item summary::-webkit-details-marker { display: none; }
.faq-item summary::after {
  content: "+";
  position: absolute;
  right: 22px;
  top: 50%;
  transform: translateY(-50%);
  font-size: 20px;
  color: var(--muted);
}
.faq-item[open] summary::after { content: "−"; }
.faq-body { padding: 0 22px 18px; font-size: 15px; color: var(--text-2); }

/* ---------- 博客卡片 ---------- */
.blog-grid { display: grid; grid-template-columns: repeat(2, 1fr); gap: 18px; }
.blog-card {
  display: block;
  padding: 24px;
  background: #fff;
  border: 1px solid var(--border);
  border-radius: var(--radius);
}
.blog-card:hover { border-color: var(--primary); color: var(--text); }
.blog-meta { display: flex; gap: 10px; align-items: center; font-size: 13px; color: var(--muted); }
.tag {
  padding: 2px 10px;
  border-radius: 999px;
  background: var(--primary-soft);
  color: var(--primary);
  font-size: 12px;
  font-weight: 600;
}
.blog-card h3 { margin-top: 10px; font-size: 18px; }
.blog-card p { margin-top: 8px; font-size: 14px; color: var(--muted); }

/* ---------- 代码块 / 表格 ---------- */
pre {
  padding: 18px 20px;
  background: #0f172a;
  color: #e2e8f0;
  border-radius: 12px;
  overflow-x: auto;
  font-size: 14px;
  line-height: 1.7;
}
code { font-family: "SFMono-Regular", Consolas, "Cascadia Mono", Menlo, monospace; }
p code, li code, td code {
  padding: 1px 6px;
  background: var(--bg-soft);
  border: 1px solid var(--border);
  border-radius: 6px;
  font-size: 14px;
  color: var(--primary-dark);
}
table { width: 100%; border-collapse: collapse; font-size: 15px; background: #fff; }
th, td { padding: 12px 16px; border: 1px solid var(--border); text-align: left; vertical-align: top; }
th { background: var(--bg-soft); font-weight: 700; }

/* ---------- 文章正文（posts/*.html 由 build.py 生成） ---------- */
.article-body { max-width: 760px; margin: 0 auto; }
.page-hero .blog-meta { justify-content: center; }
.article-body h2 { font-size: 24px; font-weight: 800; margin: 36px 0 12px; }
.article-body h3 { font-size: 19px; font-weight: 700; margin: 28px 0 10px; }
.article-body h4 { font-size: 16px; font-weight: 700; margin: 24px 0 8px; }
.article-body p { margin: 14px 0; color: var(--text-2); }
.article-body ul, .article-body ol { margin: 14px 0 14px 26px; color: var(--text-2); }
.article-body li { margin: 6px 0; }
.article-body hr { border: none; border-top: 1px solid var(--border); margin: 28px 0; }
.article-body blockquote {
  margin: 18px 0;
  padding: 12px 18px;
  border-left: 4px solid var(--primary);
  background: var(--primary-soft);
  border-radius: 0 10px 10px 0;
  color: var(--text-2);
}
.article-body img {
  display: block;
  max-width: 100%;
  margin: 18px auto;
  border: 1px solid var(--border);
  border-radius: 10px;
}
.article-body table { margin: 18px 0; }

/* ---------- 页脚 ---------- */
.site-footer { padding: 48px 0 0; background: var(--bg-soft); border-top: 1px solid var(--border); }
.footer-inner { display: grid; grid-template-columns: 2fr 1fr 1fr; gap: 32px; padding-bottom: 40px; }
.footer-logo { display: flex; align-items: center; gap: 10px; font-size: 17px; font-weight: 800; color: var(--text); }
.footer-about p { margin-top: 12px; max-width: 320px; font-size: 14px; color: var(--muted); }
.footer-col h4 { margin-bottom: 12px; font-size: 14px; }
.footer-col a { display: block; padding: 4px 0; font-size: 14px; color: var(--muted); }
.footer-col a:hover { color: var(--primary); }
.footer-bottom { padding: 18px 24px; border-top: 1px solid var(--border); font-size: 13px; color: var(--muted); text-align: center; }

/* ---------- 响应式 ---------- */
@media (max-width: 900px) {
  .section-grid, .steps { grid-template-columns: repeat(2, 1fr); }
  .footer-inner { grid-template-columns: 1fr 1fr; }
}
@media (max-width: 640px) {
  .hero h1 { font-size: 32px; }
  .section-head h2 { font-size: 26px; }
  .section-grid, .steps, .blog-grid { grid-template-columns: 1fr; }
  .header-inner { flex-direction: column; height: auto; padding: 12px 0; }
  .site-nav { justify-content: center; }
  .nav-btn { padding: 8px 14px; font-size: 14px; }
  .footer-inner { grid-template-columns: 1fr; }
}