:root{
  --bg:#fff; --accent:#0b5cff; --accent-2:#ff6b6b; --muted:#6b7280;
  --card:#ffffff; --glass:rgba(255,255,255,0.9); --maxw:1100px;
  --radius:12px;
}
*{box-sizing:border-box}
html,body{height:100%;margin:0;font-family:Inter,system-ui,-apple-system,Segoe UI,Roboto,Arial;color:#0f172a;background:linear-gradient(180deg,#fbfbff,#fff)}
.container{max-width:var(--maxw);margin:0 auto;padding:18px}

/* header */
.site-header{background:var(--card);box-shadow:0 4px 18px rgba(12,18,40,0.06);position:sticky;top:0;z-index:40}
.site-header .container{display:flex;align-items:center;justify-content:space-between;gap:12px}
.brand{font-weight:800;color:var(--accent)}
.nav{display:flex;gap:8px;align-items:center}
.nav input[type=search]{padding:8px 10px;border-radius:10px;border:1px solid #e6e9ef;min-width:220px}
.btn-ghost{background:none;border:1px solid #e6e9ef;padding:8px 10px;border-radius:8px;cursor:pointer}
.btn-primary{background:var(--accent);color:white;padding:10px 12px;border-radius:10px;border:0;cursor:pointer}

/* layout */
.main-grid{display:grid;grid-template-columns:1fr 340px;gap:18px;padding:22px 18px}
.catalog h1{margin:0 0 6px}
.muted{color:var(--muted);font-size:13px;margin-bottom:12px}

/* product grid */
.product-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(220px,1fr));gap:14px}
.card{background:var(--card);border-radius:var(--radius);padding:12px;box-shadow:0 6px 20px rgba(12,18,40,0.04)}
.card .title{font-weight:700}
.card .meta{color:var(--muted);font-size:13px;margin-top:6px}
.price{color:var(--accent-2);font-weight:800;margin-top:8px}
.card .controls{margin-top:10px;display:flex;gap:8px;align-items:center}
.card button{padding:8px 10px;border-radius:8px;border:1px solid #e6e9ef;cursor:pointer}

/* sidebar */
.sidebar{background:var(--glass);padding:14px;border-radius:12px;position:sticky;top:24px;align-self:start;box-shadow:0 6px 18px rgba(12,18,40,0.04)}
.cart-items{min-height:80px;margin-bottom:8px}
.summary{border-top:1px dashed #eef2ff;padding-top:10px}
.summary .row{display:flex;justify-content:space-between;margin:6px 0;color:var(--muted)}
.summary .total{font-weight:800;color:#111}
.actions{display:flex;gap:8px;margin-top:12px}
.accordion summary{cursor:pointer;padding:8px 6px;border-radius:8px}
.form{margin-top:10px;display:flex;flex-direction:column;gap:8px}
.form input,.form textarea{padding:8px;border-radius:8px;border:1px solid #e6e9ef}

/* message */
.message{margin-top:10px;font-size:14px;color:var(--muted)}

/* footer */
.site-footer{padding:18px 0;margin-top:18px;color:var(--muted);font-size:14px;text-align:center}

/* responsive */
@media(max-width:980px){
  .main-grid{grid-template-columns:1fr;padding:16px}
  .nav input[type=search]{min-width:140px}
  .sidebar{position:relative;top:0}
}