/* =====================================================================
   surface-trim..汽车注塑模具.中国 — 原创视觉系统 (st-)
   高端科技风：墨蓝底 + 玉青强调 + 琥珀行动色
   ===================================================================== */
:root{
  --ink:#0c1622;
  --ink-2:#13212f;
  --bg:#f3f6fa;
  --surface:#ffffff;
  --line:#e2e9f1;
  --line-2:#cdd9e6;
  --text:#1d2a38;
  --muted:#5b6b7d;
  --jade:#0fa391;
  --jade-d:#0b7d70;
  --jade-soft:#e6f6f3;
  --amber:#e8a33d;
  --amber-d:#c9851f;
  --shadow:0 6px 22px rgba(16,38,60,.08);
  --shadow-lg:0 14px 44px rgba(16,38,60,.14);
  --radius:14px;
  --radius-sm:9px;
  --maxw:1180px;
  --docw:1120px;
}
*{box-sizing:border-box}
html{scroll-behavior:smooth}
body{
  margin:0;background:var(--bg);color:var(--text);
  font-family:"PingFang SC","Hiragino Sans GB","Microsoft YaHei",-apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,Helvetica,Arial,sans-serif;
  font-size:16px;line-height:1.75;-webkit-font-smoothing:antialiased;
}
a{color:inherit;text-decoration:none}
img{max-width:100%;display:block}
h1,h2,h3,h4{color:var(--ink);line-height:1.3;font-weight:700;letter-spacing:.2px}
.wrap{max-width:var(--maxw);margin:0 auto;padding:0 24px}

/* ---------- 顶部固定导航 ---------- */
.st-nav{position:sticky;top:0;z-index:60;background:rgba(12,22,34,.92);
  backdrop-filter:saturate(160%) blur(10px);border-bottom:1px solid rgba(255,255,255,.08)}
.st-nav__inner{max-width:var(--maxw);margin:0 auto;padding:0 24px;height:62px;
  display:flex;align-items:center;justify-content:space-between;gap:18px}
.st-nav__brand{display:flex;align-items:center;gap:11px;color:#fff}
.st-logo{width:34px;height:34px;border-radius:9px;display:grid;place-items:center;
  background:linear-gradient(135deg,var(--jade),#1fd0bc);color:#04201c;font-weight:800;
  font-size:19px;box-shadow:0 4px 14px rgba(15,163,145,.45)}
.st-nav__name{display:flex;flex-direction:column;line-height:1.1;font-weight:700;font-size:16px;color:#fff}
.st-nav__name em{font-style:normal;font-size:10px;letter-spacing:1.5px;color:#7f93a6;font-weight:600;margin-top:2px}
.st-nav__links{display:flex;align-items:center;gap:6px}
.st-nav__links>a{color:#cdd9e6;font-size:14.5px;padding:8px 12px;border-radius:8px;transition:.18s}
.st-nav__links>a:hover{color:#fff;background:rgba(255,255,255,.07)}
.st-nav__links>a.is-here{color:#fff;background:rgba(15,163,145,.22)}
.st-nav__cta{margin-left:8px;padding:8px 16px;border-radius:999px;font-size:14px;font-weight:700;
  color:#04201c;background:linear-gradient(135deg,var(--amber),#f2bd6a);box-shadow:0 4px 14px rgba(232,163,61,.35)}
.st-nav__cta:hover{filter:brightness(1.05)}
.st-nav__burger{display:none;background:none;border:1px solid rgba(255,255,255,.25);color:#fff;
  border-radius:8px;padding:8px 12px;font-size:14px;cursor:pointer}

/* ---------- 移动抽屉 ---------- */
.st-drawer{position:fixed;inset:62px 0 auto 0;z-index:55;background:var(--ink-2);
  border-bottom:1px solid rgba(255,255,255,.08);padding:14px 24px 22px;display:none;flex-direction:column;gap:6px}
.st-drawer.is-open{display:flex}
.st-drawer>a{color:#cdd9e6;padding:10px 4px;border-bottom:1px solid rgba(255,255,255,.06);font-size:15px}
.st-drawer__group{border-bottom:1px solid rgba(255,255,255,.06)}
.st-drawer__toggle{width:100%;text-align:left;background:none;border:0;color:#fff;font-size:15px;
  font-weight:700;padding:12px 4px;cursor:pointer}
.st-drawer__sub{display:none;flex-direction:column;padding:0 0 8px 12px}
.st-drawer__sub.is-open{display:flex}
.st-drawer__sub>a{color:#9fb2c4;padding:8px 4px;font-size:14px}

/* ---------- 通用区块头 ---------- */
.st-sec__head{margin:0 0 26px}
.st-sec__head h2{font-size:27px;margin:0 0 8px;position:relative;padding-left:16px}
.st-sec__head h2::before{content:"";position:absolute;left:0;top:6px;bottom:6px;width:5px;border-radius:3px;
  background:linear-gradient(180deg,var(--jade),var(--amber))}
.st-sec__head p{margin:0;color:var(--muted);font-size:15px;max-width:760px}

/* ---------- HERO ---------- */
.st-hero{position:relative;background:
  radial-gradient(1100px 480px at 78% -10%,rgba(15,163,145,.30),transparent 60%),
  radial-gradient(800px 420px at 8% 8%,rgba(232,163,61,.16),transparent 55%),
  linear-gradient(160deg,var(--ink),var(--ink-2));
  color:#eaf1f7;padding:64px 0 70px;overflow:hidden}
.st-hero::after{content:"";position:absolute;inset:0;background-image:
  linear-gradient(rgba(255,255,255,.04) 1px,transparent 1px),
  linear-gradient(90deg,rgba(255,255,255,.04) 1px,transparent 1px);
  background-size:46px 46px;mask-image:radial-gradient(700px 380px at 70% 10%,#000,transparent 75%);pointer-events:none}
.st-hero .wrap{position:relative;z-index:1}
.st-hero__eyebrow{display:inline-block;font-size:12.5px;letter-spacing:2px;color:#7fe0d2;
  border:1px solid rgba(127,224,210,.35);padding:5px 12px;border-radius:999px;margin-bottom:18px;font-weight:700}
.st-hero h1{color:#fff;font-size:38px;line-height:1.28;margin:0 0 16px;max-width:880px;font-weight:800}
.st-hero__sub{font-size:17px;line-height:1.85;color:#bcccd9;max-width:820px;margin:0 0 22px}
.st-hero__tags{display:flex;flex-wrap:wrap;gap:9px;margin-bottom:26px}
.st-hero__tags span{font-size:13px;color:#dbe7f0;background:rgba(255,255,255,.07);
  border:1px solid rgba(255,255,255,.12);padding:6px 12px;border-radius:999px}
.st-hero__acts{display:flex;flex-wrap:wrap;gap:12px}
.st-btn{display:inline-flex;align-items:center;justify-content:center;padding:12px 22px;border-radius:999px;
  font-size:15px;font-weight:700;cursor:pointer;transition:.18s;border:1px solid transparent}
.st-btn--copper{color:#07261f;background:linear-gradient(135deg,var(--jade),#23d3bf);box-shadow:0 8px 22px rgba(15,163,145,.4)}
.st-btn--copper:hover{filter:brightness(1.06);transform:translateY(-1px)}
.st-btn--ghost{color:#fff;border-color:rgba(255,255,255,.4);background:rgba(255,255,255,.05)}
.st-btn--ghost:hover{background:rgba(255,255,255,.12)}

/* ---------- 工艺链 ---------- */
.st-chain{padding:60px 0 8px}
.st-chain__flow{display:grid;grid-template-columns:repeat(5,1fr);gap:14px}
.st-chain__step{background:var(--surface);border:1px solid var(--line);border-radius:var(--radius);
  padding:20px 18px;box-shadow:var(--shadow);position:relative;transition:.2s}
.st-chain__step:hover{transform:translateY(-3px);box-shadow:var(--shadow-lg);border-color:var(--jade)}
.st-chain__step b{display:inline-grid;place-items:center;width:34px;height:34px;border-radius:9px;
  background:var(--jade-soft);color:var(--jade-d);font-size:14px;font-weight:800;margin-bottom:12px}
.st-chain__step h3{font-size:17px;margin:0 0 7px}
.st-chain__step p{margin:0;font-size:13.5px;color:var(--muted);line-height:1.6}

/* ---------- 事实带 ---------- */
.st-facts{display:grid;grid-template-columns:repeat(4,1fr);gap:14px}
.st-facts>div{background:linear-gradient(160deg,#fff,#f1f7fa);border:1px solid var(--line);
  border-radius:var(--radius);padding:20px;text-align:center}
.st-facts b{display:block;font-size:22px;color:var(--jade-d);font-weight:800;letter-spacing:.5px}
.st-facts span{font-size:13px;color:var(--muted)}

/* ---------- 场景 ---------- */
.st-scenes{padding:60px 0}
.st-scenes__grid{display:grid;grid-template-columns:repeat(4,1fr);gap:16px}
.st-scenes__card{background:var(--surface);border:1px solid var(--line);border-radius:var(--radius);
  padding:22px;box-shadow:var(--shadow);transition:.2s;border-top:3px solid var(--jade)}
.st-scenes__card:hover{transform:translateY(-3px);box-shadow:var(--shadow-lg)}
.st-scenes__card h3{font-size:18px;margin:0 0 4px}
.st-scenes__card p{margin:0 0 12px;font-size:13.5px;color:var(--muted)}
.st-scenes__card ul{margin:0;padding-left:18px}
.st-scenes__card li{font-size:13.5px;color:var(--text);margin:5px 0}

/* ---------- 双栏卡片列表 ---------- */
.st-duo{padding:18px 0 64px}
.st-duo__grid{display:grid;grid-template-columns:1fr 1fr;gap:26px}
.st-cardlist{display:flex;flex-direction:column;gap:14px}
.st-cardlist__item{background:var(--surface);border:1px solid var(--line);border-radius:var(--radius);
  padding:18px 20px;box-shadow:var(--shadow);transition:.18s;display:block}
.st-cardlist__item:hover{border-color:var(--jade);transform:translateX(2px);box-shadow:var(--shadow-lg)}
.st-cardlist__item h3{font-size:17px;margin:0 0 7px;color:var(--ink)}
.st-cardlist__item p{margin:0 0 12px;font-size:13.5px;color:var(--muted);line-height:1.65;
  display:-webkit-box;-webkit-line-clamp:2;-webkit-box-orient:vertical;overflow:hidden}
.st-cardlist__meta{display:flex;justify-content:space-between;align-items:center;font-size:12.5px;color:var(--muted)}
.st-cardlist__meta span{background:var(--jade-soft);color:var(--jade-d);padding:3px 10px;border-radius:999px;font-weight:600}
.st-cardlist__more{text-align:center;color:var(--jade-d);font-weight:700;border-style:dashed}

/* ---------- 首页 FAQ ---------- */
.st-homefaq{padding:0 0 70px}
.st-homefaq details{background:var(--surface);border:1px solid var(--line);border-radius:var(--radius-sm);
  padding:14px 18px;margin-bottom:10px;box-shadow:var(--shadow)}
.st-homefaq summary{cursor:pointer;font-weight:700;color:var(--ink);font-size:15.5px}
.st-homefaq summary:hover{color:var(--jade-d)}
.st-homefaq details p{margin:10px 0 0;color:var(--muted);font-size:14.5px;line-height:1.75}
.st-homefaq a{color:var(--jade-d);font-weight:700}

/* ---------- 面包屑 ---------- */
.st-crumbs{font-size:13px;color:var(--muted);padding:18px 0 4px;display:flex;flex-wrap:wrap;align-items:center;gap:7px}
.st-crumbs a{color:var(--muted)}
.st-crumbs a:hover{color:var(--jade-d)}
.st-crumbs span[aria-current]{color:var(--ink);font-weight:600}
.st-crumbs__sep{color:var(--line-2);font-style:normal}

/* ---------- 详情文档两栏 ---------- */
.st-doc{max-width:var(--docw);margin:0 auto;padding:0 24px}
.st-doc__layout{display:grid;grid-template-columns:minmax(0,1fr) 230px;gap:36px;align-items:start}
.st-toc{position:sticky;top:82px;align-self:start;border-left:2px solid var(--line);padding:4px 0 4px 16px;max-height:calc(100vh - 110px);overflow:auto}
.st-toc-toggle{display:none;width:100%;text-align:left;background:var(--surface);border:1px solid var(--line);
  border-radius:8px;padding:10px 14px;font-weight:700;color:var(--ink);cursor:pointer;margin-bottom:10px}
.st-toc h4{margin:0 0 10px;font-size:13px;color:var(--muted);letter-spacing:1px;text-transform:uppercase}
.st-toc a{display:block;font-size:13px;color:var(--muted);padding:5px 0;line-height:1.4;border:0}
.st-toc a:hover{color:var(--jade-d)}
.st-main{background:var(--surface);border:1px solid var(--line);border-radius:var(--radius);
  padding:34px 38px;box-shadow:var(--shadow);min-width:0}
/* 面包屑左缘与正文H2左缘严格对齐：正文固定左列，TOC固定右列 */
.st-main{grid-column:1}
.st-toc{grid-column:2;grid-row:1}
@media (max-width:760px){.st-main,.st-toc{grid-column:auto}}
.st-main__cat{display:inline-block;font-size:12.5px;font-weight:700;color:var(--jade-d);
  background:var(--jade-soft);padding:4px 12px;border-radius:999px;margin-bottom:14px}
.st-main h1{font-size:30px;margin:0 0 14px;line-height:1.32}
.st-main__meta{display:flex;flex-wrap:wrap;gap:16px;font-size:13px;color:var(--muted);
  padding-bottom:16px;margin-bottom:20px;border-bottom:1px dashed var(--line)}
.st-abstract{background:linear-gradient(135deg,#f1faf8,#eef4fb);border:1px solid #d6ece8;
  border-left:4px solid var(--jade);border-radius:10px;padding:16px 18px;margin-bottom:22px}
.st-abstract__tag{display:inline-block;font-size:12px;font-weight:800;color:#fff;background:var(--jade);
  padding:3px 10px;border-radius:6px;margin-bottom:8px;letter-spacing:1px}
.st-abstract p{margin:0;font-size:15px;color:var(--text);line-height:1.8}

/* ---------- 正文排版 ---------- */
.st-prose{font-size:16px;line-height:1.95;color:#26323f}
.st-prose h2{font-size:23px;margin:38px 0 14px;padding-top:6px;scroll-margin-top:80px;
  border-left:4px solid var(--jade);padding-left:14px}
.st-prose h3{font-size:18px;margin:26px 0 10px;color:var(--ink-2)}
.st-prose p{margin:0 0 16px}
.st-prose ul{margin:0 0 16px;padding-left:22px}
.st-prose li{margin:7px 0}
.st-prose strong{color:var(--ink);font-weight:700}
.st-prose code{background:#eef3f8;border:1px solid var(--line);border-radius:5px;padding:1px 6px;
  font-size:13.5px;color:var(--jade-d);font-family:"SFMono-Regular",Consolas,Menlo,monospace}
.st-prose blockquote{margin:18px 0;background:#f7fafc;border:1px solid var(--line);border-left:4px solid var(--amber);
  border-radius:10px;padding:14px 18px}
.st-prose blockquote p{margin:0;font-size:14.5px;color:var(--text)}

/* ---------- 表格 ---------- */
.st-tablewrap{overflow-x:auto;margin:18px 0 22px}
.st-tablewrap table{border-collapse:collapse;width:100%;font-size:14px;min-width:520px}
.st-tablewrap th,.st-tablewrap td{border:1px solid var(--line);padding:10px 13px;text-align:left;vertical-align:top}
.st-tablewrap thead th{background:var(--ink);color:#fff;font-weight:700;font-size:13.5px}
.st-tablewrap tbody tr:nth-child(even){background:#f7fafc}
.st-tablewrap tbody tr:hover{background:var(--jade-soft)}

/* ---------- FAQ / 相关 / CTA ---------- */
.st-faq{margin-top:34px;border-top:1px solid var(--line);padding-top:22px}
.st-faq h2{font-size:22px;margin:0 0 14px}
.st-faq details{background:#f8fbfd;border:1px solid var(--line);border-radius:10px;padding:13px 16px;margin-bottom:10px}
.st-faq summary{cursor:pointer;font-weight:700;color:var(--ink);font-size:15.5px}
.st-faq summary:hover{color:var(--jade-d)}
.st-faq details p{margin:10px 0 0;color:var(--muted);font-size:14.5px;line-height:1.75}
.st-rel{margin-top:30px;background:#f8fbfd;border:1px solid var(--line);border-radius:12px;padding:18px 20px}
.st-rel h2{font-size:18px;margin:0 0 12px}
.st-rel ul{margin:0;padding-left:18px}
.st-rel li{margin:8px 0;font-size:14.5px}
.st-rel a{color:var(--jade-d);font-weight:600}
.st-rel a:hover{text-decoration:underline}
.st-cta-band{margin-top:30px;display:flex;align-items:center;justify-content:space-between;gap:18px;
  flex-wrap:wrap;background:linear-gradient(135deg,var(--ink),var(--ink-2));border-radius:14px;padding:22px 26px;color:#eaf1f7}
.st-cta-band__txt b{display:block;font-size:17px;color:#fff;margin-bottom:4px}
.st-cta-band__txt{font-size:14px;color:#bcccd9}

/* ---------- 列表页 ---------- */
.st-listpage{padding:8px 24px 70px}
.st-listhead{margin:10px 0 26px}
.st-listhead h1{font-size:30px;margin:0 0 8px}
.st-listhead p{margin:0;color:var(--muted);font-size:15px;max-width:780px}
.st-listgrid{display:grid;grid-template-columns:repeat(3,1fr);gap:18px}
.st-listcard{background:var(--surface);border:1px solid var(--line);border-radius:var(--radius);
  padding:20px 22px;box-shadow:var(--shadow);transition:.18s;display:block}
.st-listcard:hover{transform:translateY(-3px);box-shadow:var(--shadow-lg);border-color:var(--jade)}
.st-listcard__cat{display:inline-block;font-size:12px;font-weight:700;color:var(--jade-d);
  background:var(--jade-soft);padding:3px 10px;border-radius:999px;margin-bottom:10px}
.st-listcard h2{font-size:18px;margin:0 0 8px;line-height:1.4}
.st-listcard p{margin:0;font-size:13.5px;color:var(--muted);line-height:1.65;
  display:-webkit-box;-webkit-line-clamp:3;-webkit-box-orient:vertical;overflow:hidden}

/* ---------- 页脚 ---------- */
.st-foot{background:var(--ink);color:#aebccb;margin-top:30px;padding:48px 0 26px}
.st-foot__grid{display:grid;grid-template-columns:1.6fr 1fr 1fr;gap:30px}
.st-foot h4{color:#fff;font-size:15px;margin:0 0 14px}
.st-foot p{font-size:13.5px;line-height:1.9;margin:0;color:#92a4b6}
.st-foot a{display:block;color:#9fb2c4;font-size:14px;padding:5px 0}
.st-foot a:hover{color:var(--jade)}
.st-foot__base{border-top:1px solid rgba(255,255,255,.1);margin-top:30px;padding-top:18px;font-size:13px;color:#7f93a6}

/* ---------- 悬浮胶囊 ---------- */
.st-pill{position:fixed;right:20px;top:50%;transform:translateY(-50%);z-index:58;
  display:flex;flex-direction:column;gap:10px}
.st-pill__btn{width:50px;height:50px;border-radius:25px;border:0;cursor:pointer;font-size:13px;font-weight:700;
  color:#fff;box-shadow:var(--shadow-lg);display:grid;place-items:center;transition:.18s}
.st-pill__btn--wx{background:linear-gradient(135deg,var(--jade),#1fd0bc)}
.st-pill__btn--top{background:linear-gradient(135deg,var(--ink-2),#23384c);font-size:20px}
.st-pill__btn:hover{transform:scale(1.06)}

/* ---------- 微信名片弹层 ---------- */
.st-modal{position:fixed;inset:0;z-index:80;background:rgba(8,16,26,.62);display:none;
  align-items:center;justify-content:center;padding:20px}
.st-modal.is-open{display:flex}
.st-modal__box{background:#fff;border-radius:16px;padding:16px;box-shadow:var(--shadow-lg);
  position:relative;max-width:340px;text-align:center}
.st-modal__close{position:absolute;right:10px;top:8px;width:30px;height:30px;border:0;border-radius:50%;
  background:#eef3f8;color:var(--ink);font-size:18px;cursor:pointer;line-height:1}
.st-modal__box img{width:300px;height:500px;object-fit:contain;border-radius:10px;margin:0 auto;background:#f3f6fa}
.st-modal__hint{font-size:12.5px;color:var(--muted);margin:10px 0 0}

/* ---------- 响应式 ---------- */
@media (max-width:1080px){
  .st-chain__flow{grid-template-columns:repeat(3,1fr)}
  .st-scenes__grid{grid-template-columns:repeat(2,1fr)}
  .st-facts{grid-template-columns:repeat(2,1fr)}
  .st-duo__grid{grid-template-columns:1fr}
  .st-listgrid{grid-template-columns:repeat(2,1fr)}
}
@media (max-width:760px){
  .st-nav__links{display:none}
  .st-nav__burger{display:block}
  .st-hero h1{font-size:27px}
  .st-chain__flow,.st-scenes__grid,.st-facts,.st-listgrid{grid-template-columns:1fr}
  .st-doc__layout{grid-template-columns:1fr;gap:0}
  .st-toc-toggle{display:block}
  .st-toc{display:none;border-left:0;border-top:1px solid var(--line);padding:10px 0 0}
  .st-toc.is-open{display:block}
  .st-main{padding:22px 18px}
  .st-foot__grid{grid-template-columns:1fr}
  .st-pill{right:12px}
}