/* ============================================================
   天简传动 TIANJAN MOTION — 平台站共享样式
   独立于 tianjan.cn（服务站），品牌识别一致：#C41E2F
   ============================================================ */
:root{
  --red:#C41E2F; --red-dk:#9A1220; --red-lt:#FBE9EB;
  --ink:#12151A; --ink-2:#2A3038; --gray:#5B636D; --gray-2:#8B939D;
  --line:#E4E7EB; --line-2:#EEF0F3;
  --bg:#FFFFFF; --soft:#F6F7F9; --soft-2:#EFF1F4;
  --ok:#1E8E5A;
  --radius:6px; --radius-l:14px;
  --maxw:1180px;
  --shadow-s:0 1px 2px rgba(18,21,26,.05),0 6px 18px rgba(18,21,26,.05);
  --shadow-m:0 14px 40px rgba(18,21,26,.10);
  --shadow-l:0 30px 70px rgba(18,21,26,.14);
  --sans:"PingFang SC","Microsoft YaHei","Hiragino Sans GB","Source Han Sans SC","Noto Sans SC",-apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,sans-serif;
  --mono:"SF Mono",SFMono-Regular,"JetBrains Mono","Cascadia Mono",Consolas,Menlo,monospace;
}
*{margin:0;padding:0;box-sizing:border-box}
html{scroll-behavior:smooth;-webkit-text-size-adjust:100%;overflow-x:clip}
body{font-family:var(--sans);color:var(--ink);background:var(--bg);line-height:1.75;font-size:16px;overflow-wrap:break-word;-webkit-font-smoothing:antialiased}
img{max-width:100%;display:block}
a{color:inherit;text-decoration:none}
button{font-family:inherit;cursor:pointer;border:none;background:none}
ul{list-style:none}
::selection{background:var(--red);color:#fff}
.wrap{width:100%;max-width:var(--maxw);margin:0 auto;padding:0 24px}
.eyebrow{display:inline-flex;align-items:center;gap:10px;font-family:var(--mono);font-size:12px;font-weight:600;letter-spacing:.16em;text-transform:uppercase;color:var(--red)}
.eyebrow::before{content:"";width:22px;height:2px;background:var(--red);display:block}
section{padding:88px 0}
.section-head{max-width:760px;margin-bottom:52px}
.section-head.center{margin-left:auto;margin-right:auto;text-align:center}
.section-head.center .eyebrow{justify-content:center}
.section-head h2{font-size:clamp(26px,3.2vw,38px);line-height:1.28;font-weight:800;letter-spacing:-.01em;margin:16px 0 14px;text-wrap:balance}
.section-head p{color:var(--gray);font-size:16.5px}

/* ===== 按钮 ===== */
.btn{display:inline-flex;align-items:center;justify-content:center;gap:8px;padding:12px 24px;font-size:15px;font-weight:600;border-radius:var(--radius);transition:all .22s;white-space:nowrap;letter-spacing:.01em}
.btn-red{background:var(--red);color:#fff;box-shadow:0 4px 14px rgba(196,30,47,.26)}
.btn-red:hover{background:var(--red-dk);transform:translateY(-1px);box-shadow:0 8px 22px rgba(196,30,47,.32)}
.btn-ghost{border:1px solid var(--line);color:var(--ink);background:#fff}
.btn-ghost:hover{border-color:var(--ink);transform:translateY(-1px)}
.btn-lg{padding:15px 32px;font-size:16px}
.btn-block{width:100%}

/* ===== 顶栏 ===== */
.site-header{position:sticky;top:0;z-index:60;background:rgba(255,255,255,.9);backdrop-filter:saturate(180%) blur(14px);-webkit-backdrop-filter:saturate(180%) blur(14px);border-bottom:1px solid var(--line-2)}
.site-header.scrolled{box-shadow:0 4px 24px rgba(18,21,26,.07);border-color:var(--line)}
.site-header .wrap{display:flex;align-items:center;justify-content:space-between;height:72px;gap:20px}
.brand{display:flex;align-items:center;gap:11px;flex-shrink:0}
.brand img{height:42px;width:auto}
.brand .btag{font-family:var(--mono);font-size:10px;letter-spacing:.22em;color:var(--gray-2);border-left:1px solid var(--line);padding-left:11px;line-height:1.5}
.nav{display:flex;align-items:center;gap:2px}
.nav a{padding:8px 13px;font-size:15px;font-weight:500;color:var(--ink-2);border-radius:var(--radius);transition:color .2s;white-space:nowrap}
.nav a:hover{color:var(--red)}
.nav a.active{color:var(--red);font-weight:700}
/* 主站官网入口（显眼外链） */
.nav a.nav-official{position:relative;color:var(--red);border:1.5px solid var(--red);font-weight:600;padding:7px 14px 7px 13px;margin-left:6px}
.nav a.nav-official:hover{background:var(--red);color:#fff;transform:translateY(-1px);box-shadow:0 6px 18px rgba(196,30,47,.28)}
.nav a.nav-official::after{content:"↗";font-size:12px;margin-left:4px;opacity:.85}
.drawer-panel nav a.nav-official{color:var(--red);border:1.5px solid var(--red);margin:10px 0;border-radius:var(--radius);text-align:center;justify-content:center}
.drawer-panel nav a.nav-official::after{content:" ↗";font-size:13px}
.head-cta{display:flex;align-items:center;gap:10px;flex-shrink:0}
.burger{display:none;width:44px;height:44px;align-items:center;justify-content:center;border:1px solid var(--line);border-radius:var(--radius)}
.burger span{display:block;width:18px;height:2px;background:var(--ink);position:relative}
.burger span::before,.burger span::after{content:"";position:absolute;left:0;width:18px;height:2px;background:var(--ink);transition:.3s}
.burger span::before{top:-6px}.burger span::after{top:6px}
@media(max-width:1060px){.nav{display:none}.burger{display:flex}.head-cta .btn-ghost{display:none}}
@media(max-width:560px){.brand img{height:36px}.brand .btag{display:none}}

/* 抽屉 */
.drawer{position:fixed;inset:0;z-index:80;background:rgba(18,21,26,.45);opacity:0;visibility:hidden;transition:.3s}
.drawer.open{opacity:1;visibility:visible}
.drawer-panel{position:absolute;top:0;right:0;bottom:0;width:min(330px,88vw);background:#fff;padding:26px 24px;transform:translateX(100%);transition:transform .35s cubic-bezier(.4,0,.2,1);overflow-y:auto}
.drawer.open .drawer-panel{transform:none}
.drawer-panel .dclose{position:absolute;top:18px;right:18px;width:38px;height:38px;border:1px solid var(--line);border-radius:var(--radius);font-size:20px;color:var(--gray);line-height:1}
.drawer-panel .dlogo{height:42px;margin-bottom:24px}
.drawer-panel nav{display:flex;flex-direction:column}
.drawer-panel nav a{padding:13px 4px;font-size:17px;font-weight:600;color:var(--ink-2);border-bottom:1px solid var(--line-2)}
.drawer-panel nav a.active{color:var(--red)}
.drawer-panel .dcta{margin-top:22px}