:root {
  --blue:    #2563eb;
  --blue-dk: #1d4ed8;
  --green:   #16a34a;
  --red:     #dc2626;
  --gray-50: #f9fafb;
  --gray-100:#f3f4f6;
  --gray-200:#e5e7eb;
  --gray-600:#4b5563;
  --gray-700:#374151;
  --gray-900:#111827;
  --radius:  8px;
  --shadow:  0 1px 3px rgba(0,0,0,.1), 0 1px 2px rgba(0,0,0,.06);
  --shadow-md:0 4px 6px rgba(0,0,0,.07), 0 2px 4px rgba(0,0,0,.06);
}

*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

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(--gray-700);
  background: #fff;
}

a { color: var(--blue); text-decoration: none; }
a:hover { text-decoration: underline; }

/* ── 容器 ── */
.container { max-width: 1100px; margin: 0 auto; padding: 0 20px; }

/* ── 顶部导航 ── */
.header {
  background: #fff;
  border-bottom: 1px solid var(--gray-200);
  position: sticky; top: 0; z-index: 100;
  box-shadow: var(--shadow);
}
.header .container {
  display: flex; align-items: center;
  justify-content: space-between; height: 60px;
}
.logo {
  display: flex; align-items: center; gap: 8px;
  font-size: 18px; font-weight: 700; color: var(--gray-900);
  text-decoration: none;
}
.logo svg { width: 32px; height: 32px; flex-shrink: 0; }
.nav { display: flex; gap: 4px; }
.nav a {
  padding: 6px 14px; border-radius: var(--radius);
  font-size: 14px; font-weight: 500; color: var(--gray-600);
  text-decoration: none; transition: background .15s, color .15s;
}
.nav a:hover { background: var(--gray-100); color: var(--gray-900); }
.nav a.active { background: var(--blue); color: #fff; }

/* ── 面包屑 ── */
.breadcrumb {
  padding: 12px 20px; font-size: 13px; color: var(--gray-600);
}
.breadcrumb a { color: var(--gray-600); }
.breadcrumb a:hover { color: var(--blue); }
.breadcrumb span { margin: 0 6px; color: var(--gray-200); }

/* ── Hero 区 ── */
.hero {
  background: linear-gradient(135deg, #1e40af 0%, #2563eb 50%, #3b82f6 100%);
  color: #fff; padding: 72px 0;
  text-align: center;
}
.hero h1 { font-size: 42px; font-weight: 800; margin-bottom: 16px; }
.hero .hero-sub {
  font-size: 18px; opacity: .9;
  max-width: 600px; margin: 0 auto 32px;
}
.hero-btns { display: flex; gap: 12px; justify-content: center; flex-wrap: wrap; }

/* ── 按钮 ── */
.btn {
  display: inline-block; padding: 11px 28px;
  border-radius: var(--radius); font-size: 15px; font-weight: 600;
  cursor: pointer; transition: opacity .15s, transform .1s;
  text-decoration: none;
}
.btn:hover { opacity: .9; transform: translateY(-1px); text-decoration: none; }
.btn-primary  { background: var(--blue);  color: #fff; }
.btn-secondary { background: #fff; color: var(--blue); }

/* ── 通用 section ── */
.section { padding: 60px 0; }
.section-gray { background: var(--gray-50); }
.section-title {
  font-size: 28px; font-weight: 700; color: var(--gray-900);
  text-align: center; margin-bottom: 40px;
}

/* ── 卡片网格 ── */
.card-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(240px, 1fr));
  gap: 20px;
}
.card {
  display: block; background: #fff; border: 1px solid var(--gray-200);
  border-radius: 12px; padding: 24px 20px;
  box-shadow: var(--shadow); transition: box-shadow .2s, transform .2s;
  text-decoration: none; color: inherit;
}
.card:hover { box-shadow: var(--shadow-md); transform: translateY(-3px); text-decoration: none; }
.card-icon { margin-bottom: 14px; width: 56px; height: 56px; }
.card-icon svg { width: 56px; height: 56px; display: block; }
.card h3 { font-size: 16px; font-weight: 700; color: var(--gray-900); margin-bottom: 8px; }
.card p  { font-size: 14px; color: var(--gray-600); line-height: 1.6; margin-bottom: 12px; }
.card-link { font-size: 13px; color: var(--blue); font-weight: 600; }

/* ── 内容布局（正文+侧栏）── */
.content-layout {
  display: grid;
  grid-template-columns: 1fr 280px;
  gap: 40px;
  padding: 40px 20px;
  align-items: start;
}
.main-content { min-width: 0; }
.main-content h1 {
  font-size: 32px; font-weight: 800; color: var(--gray-900);
  margin-bottom: 16px; line-height: 1.3;
}
.main-content h2 {
  font-size: 22px; font-weight: 700; color: var(--gray-900);
  margin: 36px 0 14px; padding-bottom: 8px;
  border-bottom: 2px solid var(--gray-100);
}
.main-content h3 { font-size: 17px; font-weight: 700; margin: 24px 0 10px; color: var(--gray-900); }
.main-content p  { margin-bottom: 14px; }
.main-content ul, .main-content ol { padding-left: 20px; margin-bottom: 14px; }
.main-content li { margin-bottom: 6px; }
.lead { font-size: 17px; color: var(--gray-600); margin-bottom: 28px !important; }

/* ── 侧栏 ── */
.sidebar { position: sticky; top: 80px; }
.sidebar-card {
  background: var(--gray-50); border: 1px solid var(--gray-200);
  border-radius: 12px; padding: 20px; margin-bottom: 20px;
}
.sidebar-card h3 { font-size: 14px; font-weight: 700; color: var(--gray-900); margin-bottom: 12px; }
.sidebar-card ul { list-style: none; padding: 0; }
.sidebar-card li { margin-bottom: 8px; }
.sidebar-card a { font-size: 14px; color: var(--gray-600); }
.sidebar-card a:hover { color: var(--blue); }

/* ── 表格 ── */
.table-wrap { overflow-x: auto; margin: 20px 0; }
.compare-table {
  width: 100%; border-collapse: collapse; font-size: 14px;
}
.compare-table th {
  background: var(--gray-100); color: var(--gray-900);
  font-weight: 700; padding: 10px 14px; text-align: left;
  border-bottom: 2px solid var(--gray-200);
}
.compare-table td {
  padding: 10px 14px; border-bottom: 1px solid var(--gray-100);
  vertical-align: top;
}
.compare-table tr:hover td { background: var(--gray-50); }

/* ── 标签 ── */
.tag {
  display: inline-block; padding: 2px 10px; border-radius: 100px;
  font-size: 12px; font-weight: 600;
}
.tag-green  { background: #dcfce7; color: #166534; }
.tag-yellow { background: #fef9c3; color: #854d0e; }
.tag-red    { background: #fee2e2; color: #991b1b; }

/* ── 工具列表 ── */
.tool-list { display: flex; flex-direction: column; gap: 16px; margin: 20px 0; }
.tool-item {
  background: var(--gray-50); border: 1px solid var(--gray-200);
  border-radius: var(--radius); padding: 18px 20px;
}
.tool-item h3 { font-size: 16px; font-weight: 700; color: var(--gray-900); margin-bottom: 6px; }
.tool-item p  { font-size: 14px; margin-bottom: 8px; }
.tool-item ul { padding-left: 18px; font-size: 14px; }

/* ── 工具对比卡片 ── */
.tool-compare { display: grid; grid-template-columns: repeat(auto-fill, minmax(200px, 1fr)); gap: 16px; margin: 20px 0; }
.tool-card {
  border: 1px solid var(--gray-200); border-radius: 12px; padding: 20px;
  text-align: center;
}
.tool-card.featured { border-color: var(--blue); border-width: 2px; }
.tool-card h4 { font-size: 16px; font-weight: 700; margin-bottom: 4px; }
.tool-card .score {
  font-size: 28px; font-weight: 800; color: var(--blue); margin: 8px 0;
}
.tool-card p { font-size: 13px; color: var(--gray-600); margin-bottom: 10px; }
.tool-card ul { list-style: none; padding: 0; text-align: left; font-size: 13px; }
.tool-card li { padding: 3px 0; border-bottom: 1px solid var(--gray-100); }

/* ── 提示框 ── */
.tip-box {
  background: #eff6ff; border-left: 4px solid var(--blue);
  border-radius: 0 var(--radius) var(--radius) 0;
  padding: 14px 16px; margin: 16px 0; font-size: 14px;
}

/* ── 代码块 ── */
.code-block, pre.code-block {
  background: var(--gray-900); color: #e2e8f0;
  border-radius: var(--radius); padding: 16px 20px;
  font-family: "Cascadia Code", Consolas, monospace;
  font-size: 13px; line-height: 1.6; overflow-x: auto;
  white-space: pre; margin: 16px 0;
}

/* ── FAQ ── */
.faq-list { display: flex; flex-direction: column; gap: 12px; }
.faq-item {
  border: 1px solid var(--gray-200); border-radius: var(--radius);
  overflow: hidden;
}
.faq-q {
  background: var(--gray-50); padding: 14px 18px;
  font-weight: 700; font-size: 15px; color: var(--gray-900);
}
.faq-a { padding: 14px 18px; font-size: 14px; background: #fff; }

/* ── 排行榜 ── */
.rank-list { display: flex; flex-direction: column; gap: 14px; }
.rank-item {
  display: flex; align-items: flex-start; gap: 16px;
  padding: 18px; border: 1px solid var(--gray-200); border-radius: 12px;
  background: #fff;
}
.rank-num {
  width: 36px; height: 36px; border-radius: 50%;
  background: var(--gray-100); color: var(--gray-700);
  display: flex; align-items: center; justify-content: center;
  font-weight: 800; font-size: 16px; flex-shrink: 0;
}
.rank-item:nth-child(1) .rank-num { background: #fbbf24; color: #fff; }
.rank-item:nth-child(2) .rank-num { background: #9ca3af; color: #fff; }
.rank-item:nth-child(3) .rank-num { background: #cd7c3f; color: #fff; }
.rank-body { flex: 1; }
.rank-body h3 { font-size: 16px; font-weight: 700; color: var(--gray-900); margin-bottom: 4px; }
.rank-body p  { font-size: 14px; color: var(--gray-600); }
.rank-score { font-size: 22px; font-weight: 800; color: var(--blue); flex-shrink: 0; }

/* ── 页脚 ── */
.footer { background: var(--gray-900); color: #9ca3af; padding: 48px 0 24px; }
.footer-grid {
  display: grid; grid-template-columns: repeat(auto-fill, minmax(180px, 1fr));
  gap: 32px; margin-bottom: 32px;
}
.footer-col h4 { font-size: 14px; font-weight: 700; color: #fff; margin-bottom: 14px; }
.footer-col ul  { list-style: none; }
.footer-col li  { margin-bottom: 8px; }
.footer-col a   { font-size: 14px; color: #9ca3af; }
.footer-col a:hover { color: #fff; }
.footer-bottom { border-top: 1px solid #374151; padding-top: 20px; font-size: 13px; text-align: center; }

/* ── 响应式 ── */
@media (max-width: 768px) {
  .hero h1 { font-size: 28px; }
  .hero .hero-sub { font-size: 15px; }
  .content-layout { grid-template-columns: 1fr; }
  .sidebar { position: static; }
  .nav a { padding: 6px 10px; font-size: 13px; }
  .section-title { font-size: 22px; }
  .main-content h1 { font-size: 24px; }
}
@media (max-width: 480px) {
  .nav { gap: 2px; }
  .nav a { padding: 5px 8px; font-size: 12px; }
  .hero { padding: 48px 0; }
}