:root{--primary:#2b7cff;--primary-dark:#1a5fd0;--text:#222;--muted:#667;--border:#e2e6ee;--bg:#f6f8fb}*{box-sizing:border-box}body{color:var(--text);background:var(--bg);margin:0;font-family:PingFang TC,Noto Sans TC,system-ui,sans-serif}a{color:var(--primary);text-decoration:none}img{max-width:100%}h1{font-size:1.5rem}.site-header{border-bottom:1px solid var(--border);background:#fff;justify-content:space-between;align-items:center;padding:.9rem 1.2rem;display:flex;position:sticky;top:0}.brand{color:var(--text);font-size:1.1rem;font-weight:700}.cart-link{font-weight:500;position:relative}.cart-badge{background:var(--primary);color:#fff;border-radius:999px;margin-left:.3rem;padding:.1rem .45rem;font-size:.75rem}.container{max-width:960px;margin:0 auto;padding:1.2rem}.site-footer{text-align:center;color:var(--muted);padding:2rem 1rem;font-size:.85rem}button{font:inherit;cursor:pointer;border:1px solid var(--border);background:#fff;border-radius:8px;padding:.45rem .9rem}button:hover{border-color:var(--primary);color:var(--primary)}button.primary{background:var(--primary);color:#fff;border:none;padding:.6rem 1.4rem;font-weight:600}button.primary:hover{background:var(--primary-dark);color:#fff}button.primary:disabled{opacity:.6;cursor:not-allowed}.link-btn{color:#c33;background:0 0;border:none;padding:.2rem}.product-grid{grid-template-columns:repeat(auto-fill,minmax(210px,1fr));gap:1rem;display:grid}.product-card{border:1px solid var(--border);background:#fff;border-radius:12px;flex-direction:column;padding:.9rem;display:flex}.product-card img{border-radius:8px}.product-card h3{color:var(--text);margin:.6rem 0 .4rem;font-size:1rem}.card-bottom{justify-content:space-between;align-items:center;margin-top:auto;display:flex}.price{color:var(--primary);font-weight:700}.product-detail{border:1px solid var(--border);background:#fff;border-radius:12px;grid-template-columns:1fr 1fr;gap:1.5rem;padding:1.5rem;display:grid}@media (width<=640px){.product-detail{grid-template-columns:1fr}}.detail-info .description{color:var(--muted)}.detail-info .price{font-size:1.4rem}.detail-info .stock{color:var(--muted);font-size:.9rem}.detail-info .primary{width:100%;margin:1rem 0 .8rem;display:block}.back-link{font-size:.9rem}.qty-row{align-items:center;gap:.7rem;display:inline-flex}.qty-row button{padding:.15rem .6rem}.cart-table{border:1px solid var(--border);border-collapse:separate;border-spacing:0;background:#fff;border-radius:12px;width:100%;overflow:hidden}.cart-table th,.cart-table td{text-align:left;border-bottom:1px solid var(--border);padding:.7rem .9rem}.cart-table tr:last-child td{border-bottom:none}.cart-table th{background:var(--bg);font-size:.9rem;font-weight:600}.cart-summary{justify-content:flex-end;align-items:center;gap:1.2rem;margin-top:1rem;display:flex}.checkout-form{border:1px solid var(--border);background:#fff;border-radius:12px;flex-direction:column;gap:.9rem;max-width:480px;padding:1.5rem;display:flex}.checkout-form label{flex-direction:column;gap:.3rem;font-size:.9rem;font-weight:500;display:flex}.checkout-form input{font:inherit;border:1px solid var(--border);border-radius:8px;padding:.5rem .7rem}.checkout-form input:focus{outline:2px solid var(--primary);border-color:#0000}.checkout-summary{border-top:1px dashed var(--border);padding-top:.8rem;font-size:.92rem}.summary-row{justify-content:space-between;padding:.15rem 0;display:flex}.summary-row.total{border-top:1px solid var(--border);margin-top:.4rem;padding-top:.5rem;font-weight:700}.order-complete .total-line{font-size:1.1rem}.message{text-align:center;color:var(--muted);padding:2rem 0}.message.error{color:#c33}