* { box-sizing: border-box; }
:root{
  --bg:#f5f6f8; --card:#fff; --line:#e5e8ec; --fg:#1b2430; --muted:#6b7684;
  --accent:#1f6feb; --accent2:#0a4fbf; --ok:#137a3a; --err:#c62828; --price:#d1462f;
}
body{margin:0;background:var(--bg);color:var(--fg);font:15px/1.6 ui-sans-serif,system-ui,-apple-system,"Segoe UI",Roboto,sans-serif}

header.site{background:#fff;border-bottom:1px solid var(--line);position:sticky;top:0;z-index:10;box-shadow:0 1px 4px rgba(16,24,40,.04)}
.bar{max-width:1080px;margin:0 auto;display:flex;align-items:center;gap:18px;padding:14px 18px}
.logo{font-size:20px;font-weight:800;color:var(--fg);text-decoration:none;letter-spacing:-.02em}
.logo span{color:var(--accent)}
.navsearch{flex:1;display:flex;max-width:420px}
.navsearch input{flex:1;border:1px solid var(--line);border-right:0;border-radius:8px 0 0 8px;padding:9px 12px;font:inherit;background:#fbfcfd}
.navsearch button{border:1px solid var(--accent);background:var(--accent);color:#fff;border-radius:0 8px 8px 0;padding:9px 16px;cursor:pointer;font:inherit}
header nav{display:flex;gap:14px;align-items:center}
header nav a{color:var(--fg);text-decoration:none;font-size:14px}
header nav a:hover{color:var(--accent)}

.wrap{max-width:1080px;margin:0 auto;padding:24px 18px 60px}
h1{font-size:24px;margin:.2em 0 .6em}
h2{font-size:18px;margin:1.2em 0 .6em}

.hero{background:linear-gradient(135deg,#eaf1ff,#f7faff);border:1px solid var(--line);border-radius:14px;padding:28px;margin-bottom:24px}
.hero h1{font-size:28px;margin:0 0 6px}
.hero em{color:var(--accent);font-style:normal}
.hero p{margin:0;color:var(--muted)}

.grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(210px,1fr));gap:16px}
.card{background:var(--card);border:1px solid var(--line);border-radius:12px;padding:16px;text-decoration:none;color:inherit;transition:.15s}
.card:hover{transform:translateY(-2px);box-shadow:0 8px 24px rgba(16,24,40,.08);border-color:#cfd8e3}
.thumb{font-size:52px;text-align:center;padding:14px 0;background:#f7f9fc;border-radius:10px}
.thumb.big{font-size:110px;padding:30px 0}
.card h3{font-size:15px;margin:12px 0 4px;font-weight:600}
.price{color:var(--price);font-weight:700;margin:0}

.detail{display:grid;grid-template-columns:320px 1fr;gap:26px;background:#fff;border:1px solid var(--line);border-radius:14px;padding:22px;margin-bottom:24px}
.detail-body p{color:var(--muted)}
.buy{background:var(--accent);color:#fff;border:0;border-radius:10px;padding:11px 22px;font:inherit;font-weight:600;cursor:pointer}
.buy:hover{background:var(--accent2)}
.back{display:inline-block;margin-bottom:14px;color:var(--muted);text-decoration:none}
.back:hover{color:var(--accent)}

.reviews{background:#fff;border:1px solid var(--line);border-radius:14px;padding:20px}
.review{border-bottom:1px solid var(--line);padding:10px 0}
.review:last-of-type{border-bottom:0}
.review-head{margin-bottom:4px}
.review p{margin:0;color:#333}

.muted{color:var(--muted);font-size:13px}
.err{color:var(--err);background:#fdecea;border:1px solid #f6c9c4;padding:10px 14px;border-radius:10px}
.ok{color:var(--ok);background:#e8f5ec;border:1px solid #bfe4cb;padding:10px 14px;border-radius:10px}
code{background:#eef1f5;padding:1px 5px;border-radius:5px;font-size:13px}

.form{display:flex;flex-direction:column;gap:10px;margin:8px 0}
.form.narrow{max-width:360px}
input,textarea{border:1px solid var(--line);border-radius:9px;padding:10px 12px;font:inherit;background:#fbfcfd;width:100%}
textarea{min-height:120px;resize:vertical}
.form button{align-self:flex-start;background:var(--accent);color:#fff;border:0;border-radius:9px;padding:10px 20px;font:inherit;font-weight:600;cursor:pointer}
.form button:hover{background:var(--accent2)}

.panel{background:#fff;border:1px solid var(--line);border-radius:14px;padding:18px;margin-bottom:16px}
.filelist{list-style:none;margin:0;padding:0}
.filelist li{padding:7px 0;border-bottom:1px solid var(--line)}
.filelist li:last-child{border-bottom:0}

.term{background:#0f1720;color:#d1e7dd;padding:14px;border-radius:10px;overflow:auto;font-size:13px;white-space:pre-wrap}

footer.site{border-top:1px solid var(--line);background:#fff;margin-top:40px}
.foot{max-width:1080px;margin:0 auto;padding:18px;display:flex;justify-content:space-between;gap:12px;flex-wrap:wrap}
.foot p{margin:0}

@media (max-width:640px){
  .detail{grid-template-columns:1fr}
  .bar{flex-wrap:wrap}
  .navsearch{max-width:none;order:3;width:100%}
}