:root{
  --bg:#f6f7fb;--card:#fff;--text:#14162b;--muted:#646882;--line:#e6e8f0;
  --brand:#4f46e5;--brand2:#7c3aed;--ok:#059669;--warn:#d97706;--bad:#dc2626;
  --soft:#eef0ff;--shadow:0 1px 2px rgba(20,22,43,.04),0 4px 16px rgba(20,22,43,.06);
  --r:16px;
}
@media (prefers-color-scheme:dark){
  :root{--bg:#0d0f1a;--card:#161927;--text:#eceefa;--muted:#9aa0bd;--line:#262a3d;--soft:#1e2140;
    --shadow:0 1px 2px rgba(0,0,0,.3),0 4px 16px rgba(0,0,0,.25)}
}
*{box-sizing:border-box}
[hidden]{display:none!important}
html{-webkit-text-size-adjust:100%}
body{margin:0;font-family:system-ui,-apple-system,"Segoe UI",Roboto,"Helvetica Neue",Arial,sans-serif;
  background:var(--bg);color:var(--text);line-height:1.5;padding-bottom:calc(72px + env(safe-area-inset-bottom))}
a{color:inherit;text-decoration:none}
img{max-width:100%;display:block}
button,input,select,textarea{font:inherit;color:inherit}

/* header */
.top{position:sticky;top:0;z-index:20;display:flex;align-items:center;justify-content:space-between;
  padding:12px 16px;background:color-mix(in srgb,var(--bg) 85%,transparent);backdrop-filter:blur(12px);border-bottom:1px solid var(--line)}
.brand{display:flex;align-items:center;gap:8px;font-weight:800;font-size:18px}
.logo{display:grid;place-items:center;width:32px;height:32px;border-radius:10px;color:#fff;
  background:linear-gradient(135deg,var(--brand),var(--brand2))}
.topnav{display:none;gap:4px}
.topnav a{padding:8px 14px;border-radius:999px;color:var(--muted);font-weight:600}
.topnav a.on,.topnav a:hover{background:var(--soft);color:var(--brand)}
.badge{display:inline-grid;place-items:center;min-width:18px;height:18px;padding:0 5px;border-radius:999px;
  background:var(--bad);color:#fff;font-size:11px;font-weight:700;margin-left:4px}

.bottomnav{position:fixed;left:0;right:0;bottom:0;z-index:20;display:flex;background:var(--card);
  border-top:1px solid var(--line);padding-bottom:env(safe-area-inset-bottom)}
.bottomnav a{flex:1;display:flex;flex-direction:column;align-items:center;gap:2px;padding:8px 0;font-size:12px;color:var(--muted);font-weight:600}
.bottomnav a span{font-size:20px;position:relative}
.bottomnav .badge{position:absolute;top:-4px;right:-14px}
.bottomnav a.on{color:var(--brand)}
@media (min-width:760px){.topnav{display:flex}.bottomnav{display:none}body{padding-bottom:40px}}

main{max-width:1080px;margin:0 auto;padding:16px}
.loading,.empty{padding:48px 16px;text-align:center;color:var(--muted)}

/* hero */
.hero{border-radius:24px;padding:28px 20px;color:#fff;margin-bottom:18px;
  background:radial-gradient(circle at 85% 10%,rgba(255,255,255,.25),transparent 40%),linear-gradient(135deg,var(--brand),var(--brand2))}
.hero h1{margin:0 0 6px;font-size:clamp(24px,5vw,36px);line-height:1.2}
.hero p{margin:0;opacity:.9}
.hero .chips{display:flex;flex-wrap:wrap;gap:8px;margin-top:16px}
.hero .chips span{background:rgba(255,255,255,.18);padding:6px 12px;border-radius:999px;font-size:13px;font-weight:600}

.tabs{display:flex;gap:8px;overflow-x:auto;padding:2px 0 12px;scrollbar-width:none;margin:0 -16px;padding-left:16px;padding-right:16px}
.tabs::-webkit-scrollbar{display:none}
.tab{flex:none;border:1px solid var(--line);background:var(--card);padding:9px 16px;border-radius:999px;font-weight:600;cursor:pointer;color:var(--muted)}
.tab.on{background:var(--text);color:var(--bg);border-color:var(--text)}

.section-title{display:flex;align-items:baseline;justify-content:space-between;margin:18px 0 10px}
.section-title h2{margin:0;font-size:20px}
.section-title a{color:var(--brand);font-weight:600;font-size:14px}

.grid{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:12px}
@media (min-width:640px){.grid{grid-template-columns:repeat(3,minmax(0,1fr))}}
@media (min-width:960px){.grid{grid-template-columns:repeat(4,minmax(0,1fr));gap:16px}}

.card{background:var(--card);border:1px solid var(--line);border-radius:var(--r);overflow:hidden;box-shadow:var(--shadow);
  display:flex;flex-direction:column;transition:transform .15s}
.card:hover{transform:translateY(-2px)}
.thumb{aspect-ratio:16/10;display:grid;place-items:center;font-size:44px;position:relative;overflow:hidden}
.thumb img{width:100%;height:100%;object-fit:cover}
.thumb.course{background:linear-gradient(135deg,#dbeafe,#e0e7ff)}
.thumb.account{background:linear-gradient(135deg,#dcfce7,#ccfbf1)}
.thumb.ai{background:linear-gradient(135deg,#f3e8ff,#fce7f3)}
@media (prefers-color-scheme:dark){
  .thumb.course{background:linear-gradient(135deg,#1e2a4a,#25275a)}
  .thumb.account{background:linear-gradient(135deg,#123326,#113432)}
  .thumb.ai{background:linear-gradient(135deg,#2e1d4a,#3a1a33)}
}
.tag{position:absolute;top:8px;left:8px;font-size:11px;font-weight:700;padding:3px 8px;border-radius:999px;background:rgba(255,255,255,.9);color:#14162b}
.off{position:absolute;top:8px;right:8px;font-size:11px;font-weight:800;padding:3px 8px;border-radius:999px;background:var(--bad);color:#fff}
.card .body{padding:12px;display:flex;flex-direction:column;gap:4px;flex:1}
.card h3{margin:0;font-size:15px;line-height:1.35;display:-webkit-box;-webkit-line-clamp:2;-webkit-box-orient:vertical;overflow:hidden}
.card .short{font-size:12.5px;color:var(--muted);display:-webkit-box;-webkit-line-clamp:1;-webkit-box-orient:vertical;overflow:hidden}
.price{display:flex;align-items:baseline;gap:6px;flex-wrap:wrap;margin-top:auto;padding-top:6px}
.price b{color:var(--brand);font-size:16px}
.price s{color:var(--muted);font-size:12.5px}
.stock{font-size:12px;color:var(--ok);font-weight:600}
.stock.out{color:var(--bad)}

.btn{display:inline-flex;align-items:center;justify-content:center;gap:6px;border:0;cursor:pointer;border-radius:12px;
  padding:12px 18px;font-weight:700;background:var(--brand);color:#fff;transition:filter .15s}
.btn:hover{filter:brightness(1.08)}
.btn:disabled{opacity:.5;cursor:not-allowed}
.btn.ghost{background:var(--soft);color:var(--brand)}
.btn.line{background:transparent;border:1px solid var(--line);color:var(--text)}
.btn.ok{background:var(--ok)}
.btn.bad{background:transparent;color:var(--bad);border:1px solid var(--line)}
.btn.sm{padding:7px 12px;font-size:13px;border-radius:10px}
.btn.block{width:100%}

/* detail */
.detail{display:grid;gap:18px}
@media (min-width:760px){.detail{grid-template-columns:1.1fr 1fr;align-items:start}}
.detail .thumb{border-radius:20px;font-size:88px}
.panel{background:var(--card);border:1px solid var(--line);border-radius:20px;padding:18px;box-shadow:var(--shadow)}
.panel h1{margin:0 0 6px;font-size:24px;line-height:1.25}
.desc{white-space:pre-wrap;color:var(--muted)}
.bigprice b{font-size:26px}
.qty{display:inline-flex;align-items:center;border:1px solid var(--line);border-radius:12px;overflow:hidden}
.qty button{width:40px;height:40px;border:0;background:var(--soft);font-size:18px;cursor:pointer}
.qty span{min-width:40px;text-align:center;font-weight:700}
.row{display:flex;gap:10px;align-items:center;flex-wrap:wrap}
.perks{list-style:none;padding:0;margin:14px 0 0;display:grid;gap:6px;font-size:14px;color:var(--muted)}
.back{display:inline-block;margin-bottom:12px;color:var(--muted);font-weight:600}

/* cart */
.cart{display:grid;gap:16px}
@media (min-width:760px){.cart{grid-template-columns:1.4fr 1fr;align-items:start}}
.line{display:flex;gap:12px;align-items:center;padding:12px 0;border-bottom:1px solid var(--line)}
.line:last-child{border-bottom:0}
.line .mini{width:56px;height:56px;border-radius:12px;font-size:26px;flex:none;aspect-ratio:auto}
.line .info{flex:1;min-width:0}
.line .info b{display:block;font-size:14.5px}
.line .info small{color:var(--muted)}
.x{border:0;background:none;color:var(--muted);cursor:pointer;font-size:18px;padding:4px}
.sum{display:flex;justify-content:space-between;font-size:18px;font-weight:800;margin:12px 0}

label{display:block;font-size:13px;font-weight:600;margin:12px 0 6px;color:var(--muted)}
input,select,textarea{width:100%;padding:12px 14px;border-radius:12px;border:1px solid var(--line);background:var(--bg);outline:none}
input:focus,select:focus,textarea:focus{border-color:var(--brand)}
textarea{min-height:90px;resize:vertical}

/* order */
.status{display:inline-block;padding:4px 12px;border-radius:999px;font-weight:700;font-size:13px}
.status.pending{background:#fef3c7;color:#92400e}
.status.paid{background:#d1fae5;color:#065f46}
.status.cancelled{background:#fee2e2;color:#991b1b}
.pay{display:grid;gap:16px}
@media (min-width:760px){.pay{grid-template-columns:320px 1fr;align-items:start}}
.qr{background:#fff;border-radius:16px;padding:12px;border:1px solid var(--line)}
.kv{display:grid;grid-template-columns:auto 1fr auto;gap:8px 12px;align-items:center;font-size:14.5px}
.kv dt{color:var(--muted)}
.kv dd{margin:0;font-weight:700;word-break:break-all}
.copy{border:1px solid var(--line);background:var(--card);border-radius:8px;padding:4px 8px;font-size:12px;cursor:pointer}
.note{background:var(--soft);border-radius:12px;padding:12px 14px;font-size:14px}
.deliver{white-space:pre-wrap;word-break:break-word;background:var(--bg);border:1px dashed var(--ok);border-radius:12px;padding:12px;font-family:ui-monospace,Consolas,monospace;font-size:13.5px;margin-top:6px}
.pulse{display:inline-block;width:8px;height:8px;border-radius:50%;background:var(--warn);margin-right:6px;animation:p 1.2s infinite}
@keyframes p{50%{opacity:.3}}

/* admin */
.atabs{display:flex;gap:6px;overflow-x:auto;margin-bottom:14px;scrollbar-width:none}
.stats{display:grid;grid-template-columns:repeat(2,1fr);gap:10px;margin-bottom:14px}
@media (min-width:760px){.stats{grid-template-columns:repeat(4,1fr)}}
.stat{background:var(--card);border:1px solid var(--line);border-radius:14px;padding:12px 14px}
.stat small{color:var(--muted);font-weight:600}
.stat b{display:block;font-size:20px}
.list{display:grid;gap:10px}
.item{background:var(--card);border:1px solid var(--line);border-radius:14px;padding:14px}
.item .head{display:flex;justify-content:space-between;gap:10px;align-items:flex-start;flex-wrap:wrap}
.item .meta{font-size:13px;color:var(--muted)}
.two{display:grid;gap:0 12px}
@media (min-width:640px){.two{grid-template-columns:1fr 1fr}}
.check{display:flex;align-items:center;gap:8px;margin:12px 0;font-weight:600;color:var(--text);font-size:14px}
.check input{width:auto}
.stockrow{display:flex;gap:8px;align-items:center;font-size:13px;padding:6px 0;border-bottom:1px solid var(--line);font-family:ui-monospace,Consolas,monospace}
.stockrow span{flex:1;word-break:break-all}
.stockrow.used{opacity:.5}
.modal{position:fixed;inset:0;background:rgba(0,0,0,.5);z-index:50;display:grid;place-items:center;padding:16px}
.modal .panel{width:100%;max-width:640px;max-height:90vh;overflow:auto}

.toast{position:fixed;left:50%;bottom:calc(84px + env(safe-area-inset-bottom));transform:translateX(-50%);z-index:60;
  background:var(--text);color:var(--bg);padding:10px 18px;border-radius:999px;font-weight:600;font-size:14px;box-shadow:var(--shadow);max-width:90vw;text-align:center}
footer{max-width:1080px;margin:24px auto 0;padding:16px;color:var(--muted);font-size:13px;text-align:center}