:root{--primary:#e63946;--dark:#1d3557;--gray:#6c757d;--border:#e0e0e0;--bg:#f5f7fa}
*{box-sizing:border-box;margin:0;padding:0}
body{font-family:system-ui,-apple-system,"Segoe UI",Roboto,sans-serif;background:var(--bg);color:#222;line-height:1.5}
a{color:inherit;text-decoration:none}
.container{max-width:1200px;margin:0 auto;padding:0 16px}

/* Header */
header{background:#fff;border-bottom:1px solid var(--border);position:sticky;top:0;z-index:100;box-shadow:0 1px 4px rgba(0,0,0,.05)}
.header-inner{display:flex;align-items:center;gap:16px;padding:12px 0}
.logo{font-size:20px;font-weight:700;color:var(--primary);white-space:nowrap}
.search{flex:1;display:flex}
.search input{flex:1;padding:10px 14px;border:1px solid var(--border);border-right:none;border-radius:6px 0 0 6px;outline:none;font-size:15px}
.search button{padding:0 18px;background:var(--primary);color:#fff;border:none;border-radius0 6px 6px 0;cursor:pointer;font-size:15px}
.header-actions{display:flex;gap:10px;align-items:center}
.btn{display:inline-block;padding:9px 16px;border-radius:6px;border:1px solid transparent;cursor:pointer;font-size:14px;font-weight:500;background:#eee;transition:.15s}
.btn-primary{background:var(--primary);color:#fff}
.btn-primary:hover{background:#c92e3b}
.btn-outline{background:#fff;border-color:var(--border)}
.btn-outline:hover{border-color:var(--primary);color:var(--primary)}
.btn-sm{padding:6px 12px;font-size:13px}
.btn-block{display:block;width:100%;text-align:center}
.cart-badge{display:inline-block;min-width:20px;height:20px;line-height:20px;background:var(--primary);color:#fff;border-radius:50%;text-align:center;font-size:12px;font-weight:700;margin-left:4px}

/* Cat bar */
.cat-bar{background:#fff;border-bottom:1px solid var(--border);overflow-x:auto;white-space:nowrap;padding:8px 0}
.cat-bar a{display:inline-block;padding:6px 14px;margin-right:6px;border-radius:20px;background:#f0f0f0;font-size:14px}
.cat-bar a.active{background:var(--primary);color:#fff}

/* Layout */
.layout{display:grid;grid-template-columns:240px 1fr;gap:20px;margin:20px 0}
.sidebar{background:#fff;padding:16px;border-radius:8px;box-shadow:0 1px 4px rgba(0,0,0,.05);height:fit-content}
.sidebar h3{font-size:15px;margin-bottom:10px;color:var(--dark)}
.sidebar ul{list-style:none}
.sidebar li a{display:block;padding:6px 0;font-size:14px;color:#444}
.sidebar li a:hover,.sidebar li a.active{color:var(--primary);font-weight:600}

/* Products */
.products-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(200px,1fr));gap:14px}
.product-card{background:#fff;border-radius:8px;overflow:hidden;display:flex;flex-direction:column;box-shadow:0 1px 4px rgba(0,0,0,.05);transition:.2s;cursor:pointer}
.product-card:hover{box-shadow:0 4px 14px rgba(0,0,0,.12);transform:translateY(-2px)}
.product-thumb{position:relative;aspect-ratio:1;background:#f5f5f5;display:flex;align-items:center;justify-content:center;overflow:hidden}
.product-thumb img{width:100%;height:100%;object-fit:cover}
.product-thumb .no-img{color:#bbb;font-size:40px}
.badge-sale{position:absolute;top:8px;left:8px;background:var(--primary);color:#fff;padding:2px 8px;border-radius:4px;font-size:12px;font-weight:700}
.product-info{padding:10px 12px;display:flex;flex-direction:column;flex:1}
.product-name{font-size:14px;font-weight:500;line-height:1.4;margin-bottom:6px;display:-webkit-box;-webkit-line-clamp:2;-webkit-box-orient:vertical;overflow:hidden}
.product-price{color:var(--primary);font-weight:700;font-size:16px;margin-top:auto}
.product-price-old{color:#999;text-decoration:line-through;font-size:13px;margin-left:6px;font-weight:400}
.product-brand{font-size:12px;color:var(--gray);margin-bottom:4px}

/* Modal */
.modal{position:fixed;inset:0;background:rgba(0,0,0,.5);display:none;align-items:center;justify-content:center;z-index:200;padding:16px}
.modal.show{display:flex}
.modal-content{background:#fff;border-radius:10px;max-width:800px;width:100%;max-height:90vh;overflow-y:auto;padding:20px;position:relative}
.modal-close{position:absolute;top:10px;right:14px;font-size:26px;background:none;border:none;cursor:pointer;color:#888}
.detail-layout{display:grid;grid-template-columns:1fr 1fr;gap:20px}
.detail-img{background:#f5f5f5;border-radius:8px;aspect-ratio:1;display:flex;align-items:center;justify-content:center;overflow:hidden}
.detail-img img{width:100%;height:100%;object-fit:contain}
.detail-title{font-size:20px;margin-bottom:8px}
.specs-table{width:100%;margin-top:10px;border-collapse:collapse;font-size:14px}
.specs-table td{padding:6px 8px;border-bottom:1px solid var(--border)}
.specs-table td:first-child{color:var(--gray);width:40%}

/* Forms */
.form-group{margin-bottom:14px}
.form-group label{display:block;font-size:14px;margin-bottom:5px;font-weight:500}
.form-group input,.form-group select,.form-group textarea{width:100%;padding:9px 12px;border:1px solid var(--border);border-radius:6px;font-size:14px;font-family:inherit;outline:none}
.form-group input:focus,.form-group select:focus,.form-group textarea:focus{border-color:var(--primary)}

/* Cart */
.cart-item{display:grid;grid-template-columns:80px 1fr auto auto auto;gap:12px;align-items:center;padding:12px;background:#fff;border-radius:8px;margin-bottom:10px}
.qty-control{display:flex;align-items:center;border:1px solid var(--border);border-radius:6px;overflow:hidden}
.qty-control button{width:30px;height:32px;background:#f5f5f5;border:none;cursor:pointer;font-size:16px}
.qty-control input{width:44px;height:32px;text-align:center;border:none;border-left:1px solid var(--border);border-right:1px solid var(--border)}
.checkout-layout{display:grid;grid-template-columns:1fr 380px;gap:20px;margin:20px 0}
.cart-summary{background:#fff;padding:18px;border-radius:8px;height:fit-content;position:sticky;top:100px}
.summary-row{display:flex;justify-content:space-between;padding:8px 0}
.summary-row.total{font-size:18px;font-weight:700;color:var(--primary);border-top:1px solid var(--border);margin-top:8px;padding-top:12px}

/* Admin */
.admin-section{background:#fff;padding:20px;border-radius:8px;margin-bottom:20px;box-shadow:0 1px 4px rgba(0,0,0,.05)}
table.data-table{width:100%;border-collapse:collapse;font-size:14px}
table.data-table th,table.data-table td{padding:10;border-bottom:1px solid var(--border);text-align:left}
table.data-table th{background:#f5f7fa;font-weight:600;font-size:13px;text-transform:uppercase;color:var(--gray)}
table.data-table img{width:48px;height:48px;object-fit:cover;border-radius:4px}

/* Footer & toast */
footer{background:var(--dark);color:#ccc;padding:28px 0;margin-top:40px;font-size:14px;text-align:center}
.toast{position:fixed;bottom:24px;left:50%;transform:translateX(-50%) translateY(100px);background:#1d3557;color:#fff;padding:12px 22px;border-radius:8px;z-index:300;transition:.3s;opacity:0}
.toast.show{transform:translateX(-50%) translateY(0);opacity:1}
.empty{text-align:center;padding:60px 20px;color:var(--gray)}
.empty-icon{font-size:60px;margin-bottom:12px}

/* Auth pages (đăng ký / đăng nhập / xác thực / tài khoản) */
.auth-card{background:#fff;max-width:440px;margin:40px auto;padding:26px;border-radius:10px;box-shadow:0 1px 4px rgba(0,0,0,.06)}
.verify-block{border:1px solid var(--border);border-radius:8px;padding:14px;margin-bottom:14px}
.verify-head{display:flex;align-items:center;justify-content:space-between;gap:10px}
.badge-status{font-size:12px;font-weight:700;padding:3px 10px;border-radius:20px;background:#f1c40f22;color:#b8860b}
.badge-status.ok{background:#0a7a5422;color:#0a7a54}
.dev-note{margin-top:14px;padding:12px;background:#fff7e6;border:1px dashed #e8b84b;border-radius:8px;font-size:13px;color:#8a5a00}
.account-chip{display:inline-flex;align-items:center;gap:6px;padding:8px 14px;border-radius:6px;background:#f0f0f0;font-size:14px;font-weight:500}
.account-chip a{color:var(--primary)}
.profile-row{display:flex;gap:8px;padding:5px 0;font-size:14px}
.profile-row .lbl{color:var(--gray);min-width:140px}

/* Responsive */
@media (max-width:768px){
  .layout{grid-template-columns:1fr}
  .sidebar{display:none}
  .checkout-layout{grid-template-columns:1fr}
  .detail-layout{grid-template-columns:1fr}
  .header-inner{flex-wrap:wrap}
  .search{order:3;width:100%;flex-basis:100%}
  .cart-item{grid-template-columns:60px 1fr}
}