/* 科研工坊官网公共样式:首页与帮助中心 / 隐私政策 / 用户协议共用。首页专有的区块样式写在 index.html 里。 */
:root{
  --ink:#140F2E; --ink2:#2B2550; --sub:#5B5878; --dim:#8A87A3;
  --line:#E7E4F2; --line2:#D8D3EA; --bg:#F8F7FC; --paper:#FFFFFF; --tint:#F1EDFF;
  --indigo:#4F46E5; --violet:#7C3AED; --purple:#A855F7; --amber:#F59E0B;
  --night:#120B2E;
  --grad:linear-gradient(135deg,#4F46E5 0%,#7C3AED 60%,#A855F7 100%);
  --shadow:0 1px 2px rgba(20,15,46,.04),0 8px 24px rgba(20,15,46,.06);
  --shadow-lg:0 2px 6px rgba(20,15,46,.05),0 30px 70px rgba(60,32,140,.16);
  --r:18px; --maxw:1160px;
  --font:-apple-system,BlinkMacSystemFont,"PingFang SC","Hiragino Sans GB","Microsoft YaHei","Segoe UI",Roboto,"Helvetica Neue",sans-serif;
  --mono:"SF Mono",Menlo,Consolas,"Liberation Mono",monospace;
}
*{box-sizing:border-box;margin:0;padding:0}
html{scroll-behavior:smooth;scroll-padding-top:80px}
body{font-family:var(--font);color:var(--ink);background:var(--bg);line-height:1.7;-webkit-font-smoothing:antialiased;overflow-x:hidden}
a{color:inherit;text-decoration:none}
img,svg{display:block}
.wrap{max-width:var(--maxw);margin:0 auto;padding:0 24px}
.sprite{position:absolute;width:0;height:0;overflow:hidden}
.ic{width:22px;height:22px;fill:none;stroke:currentColor;stroke-width:1.8;stroke-linecap:round;stroke-linejoin:round;flex:none}
.grad-txt{background:var(--grad);-webkit-background-clip:text;background-clip:text;color:transparent}

/* header */
.hdr{position:sticky;top:0;z-index:60;background:rgba(248,247,252,.8);
  backdrop-filter:saturate(1.6) blur(14px);-webkit-backdrop-filter:saturate(1.6) blur(14px);
  border-bottom:1px solid transparent;transition:border-color .2s,box-shadow .2s}
.hdr.scrolled{border-bottom-color:var(--line);box-shadow:0 6px 20px rgba(20,15,46,.04)}
.nav{height:68px;display:flex;align-items:center;gap:28px}
.brand{display:flex;align-items:center;gap:11px;flex:none}
.brand img{width:36px;height:36px}
.brand b{display:block;font-size:18px;font-weight:800;letter-spacing:.06em;line-height:1.15;color:var(--ink)}
.brand small{display:block;font-size:10px;letter-spacing:.28em;color:var(--dim);text-transform:uppercase;line-height:1.3}
.links{display:flex;gap:4px;margin-left:auto}
.links a{font-size:14.5px;color:var(--sub);padding:8px 13px;border-radius:9px;transition:color .15s,background .15s}
.links a:hover,.links a[aria-current="page"]{color:var(--ink);background:rgba(124,58,237,.08)}
.nav .cta{display:inline-flex;align-items:center;gap:8px;background:var(--ink);color:#fff;font-size:14px;font-weight:700;
  padding:9px 16px;border-radius:10px;transition:transform .15s,background .15s}
.nav .cta:hover{background:#2A2152;transform:translateY(-1px)}
.nav .cta .ic{width:17px;height:17px}
.menu-btn{display:none;margin-left:auto;width:40px;height:40px;border:1px solid var(--line2);border-radius:10px;
  background:var(--paper);color:var(--ink);cursor:pointer;align-items:center;justify-content:center}

/* buttons */
.btn{display:inline-flex;align-items:center;justify-content:center;gap:10px;padding:14px 24px;border-radius:13px;
  font-size:16px;font-weight:700;border:1px solid transparent;cursor:pointer;transition:transform .18s,box-shadow .18s,border-color .18s,background .18s}
.btn .ic{width:19px;height:19px}
.btn-primary{background:var(--grad);color:#fff;box-shadow:0 10px 28px rgba(109,59,234,.30)}
.btn-primary:hover{transform:translateY(-2px);box-shadow:0 14px 36px rgba(109,59,234,.40)}
.btn-ghost{background:var(--paper);color:var(--ink);border-color:var(--line2)}
.btn-ghost:hover{border-color:var(--violet);color:var(--violet)}

/* section heads */
.eyebrow{display:inline-flex;align-items:center;gap:8px;font-size:13px;font-weight:700;letter-spacing:.14em;color:var(--violet);text-transform:uppercase}
.eyebrow::before{content:"";width:18px;height:2px;border-radius:2px;background:var(--grad)}
.h2{font-size:clamp(28px,3.6vw,40px);line-height:1.25;font-weight:820;letter-spacing:-.015em;margin:12px 0}
.h2sub{font-size:16.5px;color:var(--sub);max-width:640px}
.head{margin-bottom:40px}
.head.center{text-align:center}.head.center .h2sub{margin:0 auto}
.h2,.dl h2{text-wrap:balance;word-break:keep-all}

/* footer */
.ft{border-top:1px solid var(--line);padding:44px 0 40px;color:var(--dim);font-size:13.5px;background:var(--paper)}
.ft-top{display:flex;justify-content:space-between;gap:40px;flex-wrap:wrap}
.ft-brand{max-width:360px}
.ft-brand .brand img{width:30px;height:30px}
.ft-brand .brand b{font-size:16px}
.ft-brand p{margin-top:12px}
.ft-cols{display:flex;gap:56px;flex-wrap:wrap}
.ft-col{display:flex;flex-direction:column;gap:8px}
.ft-col h5{font-size:13px;color:var(--ink);font-weight:700;margin-bottom:2px}
.ft-col a{color:var(--sub)}
.ft-col a:hover{color:var(--violet)}
.ft-bottom{margin-top:30px;padding-top:20px;border-top:1px dashed var(--line);display:flex;justify-content:space-between;flex-wrap:wrap;gap:10px}

/* reveal */
.js .reveal{opacity:0;transform:translateY(18px);transition:opacity .6s ease,transform .6s ease}
.js .reveal.in{opacity:1;transform:none}

/* document pages: help / privacy / terms */
.doc-hero{padding:56px 0 36px;border-bottom:1px solid var(--line);
  background:radial-gradient(620px 260px at 10% 0%,rgba(79,70,229,.12),transparent 70%),radial-gradient(520px 260px at 90% 0%,rgba(168,85,247,.10),transparent 70%)}
.doc-hero h1{font-size:clamp(30px,4vw,42px);font-weight:820;letter-spacing:-.01em}
.doc-meta{margin-top:8px;color:var(--sub);font-size:14.5px}
.draft-note{margin-top:14px;display:inline-flex;align-items:center;gap:8px;padding:7px 12px;border-radius:10px;
  background:#FFF7EA;border:1px solid #FFE1AE;color:#7A5212;font-size:13.5px}
.draft-note .ic{width:16px;height:16px;color:#E29A1D}
.doc{display:grid;grid-template-columns:220px minmax(0,1fr);gap:48px;padding-top:36px;padding-bottom:72px;align-items:start}
.doc-toc{position:sticky;top:92px;display:flex;flex-direction:column;gap:2px;font-size:14px;max-height:calc(100vh - 110px);overflow:auto}
.doc-toc a{padding:6px 12px;border-radius:8px;color:var(--sub);border-left:2px solid transparent}
.doc-toc a:hover{color:var(--ink);background:var(--tint)}
.doc-toc a.on{color:var(--violet);background:var(--tint);border-left-color:var(--violet);font-weight:650}
.doc-body{max-width:780px;font-size:15.5px;color:var(--ink2)}
.doc-body h2{font-size:22px;font-weight:780;color:var(--ink);margin:40px 0 14px;padding-top:6px}
.doc-body h2:first-child{margin-top:0}
.doc-body h3{font-size:17px;font-weight:720;color:var(--ink);margin:24px 0 10px}
.doc-body p{margin:0 0 12px}
.doc-body ul,.doc-body ol{margin:0 0 14px;padding-left:22px}
.doc-body li{margin:6px 0}
.doc-body strong{color:var(--ink);font-weight:700}
.doc-body code,.kbd{font:13px var(--mono);background:var(--tint);color:#5B21B6;padding:1px 6px;border-radius:6px}
.kbd{border:1px solid var(--line2);background:var(--paper);color:var(--ink2);box-shadow:0 1px 0 var(--line2)}
.doc-body a{color:var(--violet);text-decoration:underline;text-underline-offset:3px}
.tbl{width:100%;border-collapse:collapse;margin:6px 0 16px;font-size:14.5px;background:var(--paper);border:1px solid var(--line);border-radius:12px;overflow:hidden}
.tbl th,.tbl td{text-align:left;padding:10px 14px;border-top:1px solid var(--line);vertical-align:top}
.tbl tr:first-child th{border-top:none;background:#F6F4FC;color:var(--sub);font-weight:650;font-size:13.5px}
.tbl td:first-child{white-space:nowrap;font-weight:650;color:var(--ink)}
.tip{margin:10px 0 16px;padding:12px 16px;border-radius:12px;background:var(--tint);border:1px solid #E4DCFD;color:#3B2A7A;font-size:14.5px}
.steps-list{list-style:none;padding:0 !important;counter-reset:st;margin:6px 0 16px}
.steps-list li{position:relative;padding:14px 16px 14px 58px;margin:10px 0;background:var(--paper);border:1px solid var(--line);border-radius:14px}
.steps-list li::before{counter-increment:st;content:counter(st);position:absolute;left:16px;top:14px;width:28px;height:28px;border-radius:50%;
  display:grid;place-items:center;background:var(--grad);color:#fff;font-weight:800;font-size:14px}
.steps-list b{display:block;color:var(--ink);margin-bottom:2px}
.help-search{position:relative;margin-top:22px;max-width:520px}
.help-search input{width:100%;height:48px;border-radius:14px;border:1px solid var(--line2);background:var(--paper);padding:0 16px 0 46px;
  font:15px var(--font);color:var(--ink);outline:none;box-shadow:var(--shadow);transition:border-color .15s,box-shadow .15s}
.help-search input:focus{border-color:var(--violet);box-shadow:0 0 0 4px rgba(124,58,237,.12)}
.help-search .ic{position:absolute;left:15px;top:13px;color:var(--dim)}
.help-sec[hidden]{display:none}
.help-empty{padding:24px;border:1px dashed var(--line2);border-radius:14px;color:var(--sub);text-align:center}

@media (prefers-reduced-motion:reduce){
  html{scroll-behavior:auto}
  .js .reveal{opacity:1;transform:none;transition:none}
}
@media (max-width:900px){
  .doc{grid-template-columns:1fr;gap:20px}
  .doc-toc{position:static;flex-direction:row;flex-wrap:wrap;max-height:none;gap:6px}
  .doc-toc a{border:1px solid var(--line);border-left-width:1px;background:var(--paper);padding:5px 11px;border-radius:999px;font-size:13px}
  .doc-toc a.on{border-color:var(--violet)}
}
@media (max-width:860px){
  .links{display:none;position:absolute;top:68px;left:0;right:0;flex-direction:column;padding:10px 16px 16px;
    background:rgba(248,247,252,.97);border-bottom:1px solid var(--line);box-shadow:0 18px 30px rgba(20,15,46,.08)}
  .hdr.open .links{display:flex}
  .links a{padding:12px}
  .menu-btn{display:inline-flex}
  .nav .cta{display:none}
}
@media (max-width:600px){
  .ft-cols{gap:32px}
  .ft-bottom{flex-direction:column}
  .tbl td:first-child{white-space:normal}
}