/* 颜色与基线 */
:root{
  --bg:#ffffff;--text:#0b1220;--muted:#6B7280;--primary:#1B5FBF;--primary-ink:#0B2545;--alt:#F3F4F6;--line:#e5e7eb;
}
*{box-sizing:border-box}
html,body{margin:0;padding:0;background:var(--bg);color:var(--text);font-family:-apple-system,BlinkMacSystemFont,Segoe UI,Roboto,Inter,Helvetica,Arial,"Noto Sans SC","PingFang SC","Microsoft YaHei",sans-serif;line-height:1.6}
img{max-width:100%;height:auto}
a{color:var(--primary);text-decoration:none}
a:hover{text-decoration:underline}
.container{max-width:1100px;margin:0 auto;padding:0 16px}
.row{display:flex;gap:16px}
.between{justify-content:space-between}.center{align-items:center}
.top{align-items:flex-start}
.tiny{font-size:12px}
.muted{color:var(--muted)}
.list{margin:0;padding-left:18px}

/* 头部与导航 */
.site-header{position:sticky;top:0;background:#fff;border-bottom:1px solid var(--line);z-index:20}
.brand{gap:10px}
.brand .logo{display:block}
.brand-text{font-weight:700;color:var(--primary-ink)}
.nav{display:flex;gap:18px}
.nav a{padding:10px 6px;color:var(--primary-ink)}
.nav a.active{color:var(--primary)}
.nav-toggle{display:none;border:1px solid var(--line);background:#fff;border-radius:6px;padding:6px 10px}

/* 主视觉 */
.hero{background:linear-gradient(180deg,#0B2545 0%,#14365f 100%);color:#fff;padding:56px 0}
.hero h1{font-size:32px;margin:0 0 8px}
.hero p{max-width:720px;margin:0 0 20px}
.hero-cta{display:flex;gap:12px}

/* 区块 */
.section{padding:40px 0}
.section.alt{background:var(--alt)}
.section-title{margin:0 0 16px;font-size:24px;color:var(--primary-ink)}
.grid{display:grid;gap:16px}
.grid.cards{grid-template-columns:repeat(auto-fit,minmax(220px,1fr))}
.grid.two{grid-template-columns:repeat(auto-fit,minmax(280px,1fr))}
.grid.three{grid-template-columns:repeat(auto-fit,minmax(220px,1fr))}
.card{border:1px solid var(--line);border-radius:10px;padding:16px;background:#fff;transition:box-shadow .2s,transform .2s}
.card:hover{box-shadow:0 6px 18px rgba(0,0,0,.08);transform:translateY(-2px)}
.feature{border-left:4px solid var(--primary);padding:10px 12px;background:#fff;border-radius:6px;border:1px solid var(--line)}
.badges{display:flex;gap:10px;list-style:none;padding:0;margin:6px 0 0}
.badges li{border:1px dashed var(--line);border-radius:999px;padding:6px 10px;background:#fff}
.cta-box{border:1px solid var(--line);border-radius:12px;padding:16px;background:#fafafa;margin-top:18px}

/* 按钮 */
.btn{display:inline-block;border-radius:8px;padding:10px 14px;border:1px solid var(--primary);color:#fff;background:var(--primary)}
.btn:hover{text-decoration:none;filter:brightness(.95)}
.btn-outline{background:#fff;color:var(--primary)}
.btn-primary{background:var(--primary);border-color:var(--primary)}

/* 页脚 */
.site-footer{border-top:1px solid var(--line);padding:24px 0;background:#fff}
.footer-grid{gap:28px}

/* 下载列表 */
.downloads{list-style:none;padding:0;margin:0}
.downloads li{padding:10px 0;border-bottom:1px solid var(--line)}

/* 地图占位 */
.map-placeholder{height:220px;border:1px dashed var(--line);border-radius:8px;display:flex;align-items:center;justify-content:center;color:var(--muted)}

/* 小屏适配 */
@media (max-width: 840px){
  .nav{display:none;flex-direction:column;background:#fff;position:absolute;right:16px;top:56px;border:1px solid var(--line);border-radius:10px;padding:8px 10px}
  .nav-toggle{display:block}
}

/* 居中页面（404） */
.center-page{min-height:100vh;display:grid;place-items:center}