:root{
  --bg:#EDF1F5; --surface:#FFFFFF; --ink:#16233B; --muted:#5B677A; --rule:#D3DAE3;
  --hi:#FFD54A; --red:#C2362B; --focus:#2F6FEB; --shade:rgba(22,35,59,.10);
  --display:"Bricolage Grotesque","Avenir Next","Segoe UI","PingFang HK","Noto Sans HK","Microsoft JhengHei",system-ui,sans-serif;
  --body:"Instrument Sans","Helvetica Neue",Arial,"PingFang HK","Noto Sans HK","Microsoft JhengHei",system-ui,sans-serif;
}
@media (prefers-color-scheme:dark){:root{
  --bg:#121925; --surface:#1B2432; --ink:#E7ECF3; --muted:#98A3B4; --rule:#2B3647;
  --hi:#F2C640; --red:#E36A5E; --focus:#7AA7FF; --shade:rgba(0,0,0,.35);
}}
*,*::before,*::after{box-sizing:border-box}
body{margin:0;background:var(--bg);color:var(--ink);font:16px/1.55 var(--body);min-height:100vh;display:flex;flex-direction:column}
img{max-width:100%;display:block}
a{color:inherit}
button,input,select,textarea{font:inherit;color:inherit}
:focus-visible{outline:3px solid var(--focus);outline-offset:2px}
.wrap{width:100%;max-width:1120px;margin:0 auto;padding:0 20px}
main{flex:1;padding-bottom:60px}
h1{font:800 clamp(1.9rem,4.5vw,2.8rem)/1.05 var(--display);letter-spacing:-.02em;margin:28px 0 8px}
h2{font:700 1.35rem/1.2 var(--display);margin:28px 0 10px}
h3{font:700 1.05rem/1.3 var(--display);margin:0}
.lead{color:var(--muted);max-width:62ch;margin:0 0 18px}
.muted{color:var(--muted)}
.small{font-size:.87rem}

/* Header */
.top{background:var(--surface);border-bottom:1px solid var(--rule);position:sticky;top:0;z-index:5}
.bar{display:flex;align-items:center;gap:18px;min-height:62px;flex-wrap:wrap}
.brand{font:800 1.45rem var(--display);text-decoration:none;letter-spacing:-.02em;display:flex;align-items:center;gap:9px}
.brand img{width:30px;height:30px}
nav{display:flex;gap:4px;flex-wrap:wrap}
nav a{text-decoration:none;padding:7px 11px;border-radius:8px;color:var(--muted);font-weight:500}
nav a[aria-current="page"]{color:var(--ink);background:var(--bg)}
.right{margin-left:auto;display:flex;gap:10px;align-items:center}
.lang{display:flex;border:1px solid var(--rule);border-radius:8px;overflow:hidden;font-size:.85rem}
.lang button{border:0;background:none;padding:5px 9px;cursor:pointer}
.lang button[aria-pressed="true"]{background:var(--ink);color:var(--bg)}
.lang button:disabled{cursor:not-allowed;opacity:.5}

/* The exchange slip: SwapSheet's signature element */
.slip{position:relative;border:1.5px dashed var(--ink);border-radius:6px;padding:4px 12px 4px 16px;display:flex;align-items:center;gap:8px;text-decoration:none;background:var(--surface)}
.slip::before{content:"";position:absolute;left:-7px;top:50%;margin-top:-6px;width:12px;height:12px;border-radius:50%;background:var(--surface);border:1.5px dashed var(--ink)}
.slip b{font:800 1.5rem/1 var(--display);color:var(--red)}
.slip span{font-size:.8rem;color:var(--muted);line-height:1.2}

/* Buttons and fields */
.btn{display:inline-flex;align-items:center;justify-content:center;gap:6px;border:0;border-radius:10px;padding:10px 16px;font-weight:600;cursor:pointer;background:var(--ink);color:var(--bg);text-decoration:none}
.btn.hi{background:var(--hi);color:#16233B}
.btn.ghost{background:transparent;color:var(--ink);border:1px solid var(--rule)}
.btn.danger{background:var(--red);color:#fff}
.btn.sm{padding:7px 12px;font-size:.88rem}
.btn:disabled{opacity:.45;cursor:not-allowed}
.link{background:none;border:0;padding:0;color:var(--muted);text-decoration:underline;text-underline-offset:3px;cursor:pointer}
label.f{display:grid;gap:5px;font-weight:600;font-size:.92rem}
input[type=text],input[type=email],input[type=number],input[type=search],select,textarea{width:100%;border:1px solid var(--rule);border-radius:9px;padding:10px 12px;background:var(--surface);font-weight:400}
textarea{min-height:100px;resize:vertical}
.check{display:flex;gap:10px;align-items:flex-start;font-size:.9rem;color:var(--muted)}
.check input{margin-top:4px}
.grid2{display:grid;grid-template-columns:1fr 1fr;gap:14px}
.stack{display:grid;gap:14px}
.err{color:var(--red);font-size:.92rem;min-height:1.3em}
.ok{color:#2E7D4F}
.note{background:var(--surface);border:1px solid var(--rule);border-left:5px solid var(--hi);border-radius:8px;padding:12px 14px}
.warn{border-left-color:var(--red)}

/* Filters */
.filters{display:flex;gap:10px;flex-wrap:wrap;align-items:center;margin:8px 0 6px}
.filters input{flex:1 1 260px}
.filters select{width:auto}
.chips{display:flex;gap:8px;overflow-x:auto;padding:6px 2px 12px}
.chip{flex:none;border:1px solid var(--rule);background:var(--surface);border-radius:999px;padding:6px 13px;cursor:pointer;font-size:.88rem;display:flex;gap:7px;align-items:center}
.chip i{width:9px;height:9px;border-radius:50%;background:var(--c,var(--muted))}
.chip[aria-pressed="true"]{background:var(--ink);color:var(--bg);border-color:var(--ink)}

/* Document cards: sheets of paper */
.cards{display:grid;grid-template-columns:repeat(auto-fill,minmax(220px,1fr));gap:18px}
.sheet{position:relative;background:var(--surface);border:1px solid var(--rule);border-radius:4px;text-decoration:none;display:flex;flex-direction:column;overflow:hidden}
.sheet::before{content:"";position:absolute;left:0;top:0;bottom:0;width:5px;background:var(--c,var(--muted));z-index:1}
.thumb{aspect-ratio:4/3;background:var(--bg);overflow:hidden;border-bottom:1px solid var(--rule)}
.thumb img{width:100%;height:100%;object-fit:cover;object-position:top}
.thumb.blank{background-image:repeating-linear-gradient(to bottom,transparent 0 17px,var(--rule) 17px 18px)}
.sheet .body{padding:12px 14px 14px 18px;display:grid;gap:6px}
.meta{font-size:.82rem;color:var(--muted);display:flex;flex-wrap:wrap;gap:3px 10px}
.tag{font-size:.76rem;padding:2px 8px;border-radius:5px;background:var(--bg);color:var(--muted);justify-self:start}
.tag.free{color:#2E7D4F}.tag.own{color:var(--red)}
.empty{text-align:center;padding:50px 20px;border:1.5px dashed var(--rule);border-radius:10px;color:var(--muted)}
.empty strong{display:block;color:var(--ink);font:700 1.25rem var(--display);margin-bottom:6px}

/* Document page */
.docpage{display:grid;grid-template-columns:minmax(0,1.5fr) minmax(280px,1fr);gap:28px;align-items:start;margin-top:22px}
.pages{display:grid;gap:14px}
.page{background:#fff;border:1px solid var(--rule);border-radius:4px;box-shadow:0 6px 20px var(--shade);overflow:hidden}
.lockband{position:relative;border:1.5px dashed var(--rule);border-radius:6px;padding:26px 18px;text-align:center;color:var(--muted);background:repeating-linear-gradient(to bottom,var(--surface) 0 17px,var(--rule) 17px 18px)}
.lockband strong{display:block;color:var(--ink);font:700 1.1rem var(--display);background:var(--surface);padding:2px 0}
.fade{position:relative}
.fade::after{content:"";position:absolute;left:0;right:0;bottom:0;height:40%;background:linear-gradient(to bottom,transparent,var(--surface))}
.panel{background:var(--surface);border:1px solid var(--rule);border-radius:10px;padding:20px;display:grid;gap:12px;position:sticky;top:80px}
.panel dl{display:grid;grid-template-columns:auto 1fr;gap:4px 12px;margin:0;font-size:.92rem}
.panel dt{color:var(--muted)}
.panel dd{margin:0}

/* Sponsors */
.sponsor{background:var(--surface);border:1px solid var(--rule);border-radius:10px;padding:18px;display:grid;gap:12px;margin-bottom:18px}
.sponsor .head{display:flex;gap:14px;align-items:center;flex-wrap:wrap}
.sponsor .logo{width:56px;height:56px;border-radius:10px;object-fit:contain;background:#fff;border:1px solid var(--rule)}

/* Tables and lists */
.list{display:grid;gap:10px}
.row{background:var(--surface);border:1px solid var(--rule);border-radius:9px;padding:12px 14px;display:grid;gap:6px}
.row .acts{display:flex;gap:8px;flex-wrap:wrap}

/* Dialog */
dialog{border:0;border-radius:14px;padding:0;background:var(--surface);color:var(--ink);width:min(560px,94vw);max-height:92vh;box-shadow:0 20px 60px var(--shade)}
dialog.wide{width:min(960px,96vw)}
dialog::backdrop{background:rgba(10,16,28,.55)}
.dlg{padding:22px;display:grid;gap:14px}
.viewer{width:100%;height:75vh;border:1px solid var(--rule);border-radius:8px;background:#fff}

.foot{display:flex;flex-wrap:wrap;gap:8px 20px;padding:22px 20px 30px;border-top:1px solid var(--rule);font-size:.87rem;color:var(--muted)}
.foot a{color:inherit}
.prose{max-width:70ch}
.prose h2{font-size:1.1rem;margin:22px 0 6px}
.prose p,.prose li{margin:.35rem 0}

@media (max-width:760px){
  .docpage{grid-template-columns:1fr}
  .panel{position:static}
  .grid2{grid-template-columns:1fr}
  nav{order:3;width:100%;overflow-x:auto;flex-wrap:nowrap}
}

/* Account button (top right) */
.acct{display:flex;align-items:center;gap:9px;text-decoration:none;padding:4px 10px 4px 4px;border:1px solid var(--rule);border-radius:999px;background:var(--surface)}
.acct[aria-current="page"]{border-color:var(--ink)}
.av{width:30px;height:30px;border-radius:50%;background:var(--ink);color:var(--bg);display:grid;place-items:center;font:700 .95rem var(--display)}
.acct-t{display:grid;line-height:1.15}
.acct-t b{font-size:.88rem}
.acct-t small{font-size:.76rem;color:var(--red);font-weight:600}

/* Folders: the tab on top makes each tile read as a file folder */
.folders{display:grid;grid-template-columns:repeat(auto-fill,minmax(170px,1fr));gap:22px 16px;margin:18px 0 8px}
.folder{position:relative;display:grid;gap:4px;text-decoration:none;background:var(--surface);border:1px solid var(--rule);border-top:4px solid var(--c,var(--muted));border-radius:0 8px 8px 8px;padding:14px 14px 12px;min-height:84px}
.folder::before{content:"";position:absolute;top:-14px;left:-1px;width:44%;height:12px;background:var(--c,var(--muted));border-radius:6px 6px 0 0}
.folder:hover{border-color:var(--c,var(--ink))}
.fname{font:700 1rem/1.25 var(--display)}
.fcount{font-size:.82rem;color:var(--muted)}
.crumbs{display:flex;flex-wrap:wrap;gap:6px;align-items:center;font-size:.9rem;color:var(--muted);margin:-2px 0 10px}
.crumbs a{color:var(--muted)}
a.chip{text-decoration:none;color:var(--ink)}

/* Account page */
.acctgrid{display:grid;grid-template-columns:repeat(auto-fit,minmax(280px,1fr));gap:18px}
.box{background:var(--surface);border:1px solid var(--rule);border-radius:10px;padding:18px;display:grid;gap:10px;align-content:start}
.box h2{margin:0}
.kv{display:grid;grid-template-columns:auto 1fr;gap:4px 14px;margin:0;font-size:.95rem}
.kv dt{color:var(--muted)}.kv dd{margin:0;overflow-wrap:anywhere}
.bignum{font:800 3rem/1 var(--display);color:var(--red)}

/* Moderator tools */
.adminbox{border:1.5px dashed var(--red);border-radius:8px;padding:10px 12px;display:grid;gap:8px}
.subgrid{display:grid;grid-template-columns:repeat(auto-fill,minmax(150px,1fr));gap:6px 12px;max-height:240px;overflow:auto;border:1px solid var(--rule);border-radius:8px;padding:10px}