:root {
    --primary-color: #27ae60;
    --primary-hover: #219150;
    --dark-color: #2c3e50;
    --light-bg: #f4f7f6;
    --accent-color: #e67e22;
    --text-color: #333;
}

body { font-family: 'Roboto', sans-serif; background: #fff; margin: 0; color: var(--text-color); }

header { background: white; padding: 15px 8%; display: flex; justify-content: space-between; align-items: center; box-shadow: 0 2px 15px rgba(0,0,0,0.1); position: sticky; top: 0; z-index: 1000; }
.logo { font-size: 26px; font-weight: bold; color: var(--primary-color); text-decoration: none; display: flex; align-items: center; gap: 10px; }
nav a { margin-left: 25px; text-decoration: none; color: var(--dark-color); font-weight: 500; }
.cart-icon { position: relative; }
.cart-count { position: absolute; top: -8px; right: -10px; background: #e74c3c; color: white; border-radius: 50%; width: 18px; height: 18px; font-size: 11px; display: flex; align-items: center; justify-content: center; }
.user-icon { margin-left: 16px; color: var(--dark-color); text-decoration:none; font-size: 1rem; display:inline-flex; align-items:center; gap:6px; cursor: pointer; }
.user-icon i { font-size: 18px; }

.user-dropdown { position: relative; display: inline-block; }
.dropdown-content {
    display: none;
    position: absolute;
    right: 0;
    background: white;
    min-width: 150px;
    box-shadow: 0 8px 16px rgba(0,0,0,0.1);
    border-radius: 8px;
    z-index: 1001;
    overflow: hidden;
}
.dropdown-content a {
    color: var(--dark-color);
    padding: 12px 16px;
    text-decoration: none;
    display: block;
    font-size: 14px;
    margin: 0;
}
.dropdown-content a:hover { background: #f8f9fa; }

.breadcrumb { padding: 20px 8%; background: var(--light-bg); font-size: 14px; color: #7f8c8d; }
.breadcrumb a { color: var(--primary-color); text-decoration: none; }

.product-container { display: grid; grid-template-columns: 1fr 1fr; gap: 50px; padding: 40px 8%; max-width: 1400px; margin: 0 auto; }

.product-gallery { display: flex; flex-direction: column; gap: 15px; }
.main-image { width: 100%; border-radius: 15px; border: 1px solid #eee; overflow: hidden; background: #fff; }
.main-image img { width: 100%; height: 450px; object-fit: contain; padding: 20px; display: block; transition: transform 0.5s; image-rendering: -webkit-optimize-contrast; }
.main-image img:hover { transform: scale(1.02); }

.product-info-detail h1 { font-size: 2rem; color: var(--dark-color); margin-top: 0; }
.sku { color: #95a5a6; font-size: 0.9rem; margin-bottom: 15px; }
.price-large { font-size: 2.2rem; color: #e74c3c; font-weight: 800; margin: 20px 0; }
.short-desc { line-height: 1.8; color: #666; margin-bottom: 25px; border-bottom: 1px solid #eee; padding-bottom: 20px; white-space: pre-wrap; }

.purchase-zone { display: flex; gap: 15px; align-items: center; margin-top: 30px; flex-wrap: wrap; }
.quantity-select { display: flex; align-items: center; border: 1px solid #ddd; border-radius: 8px; overflow: hidden; height: 48px; }
.quantity-select button { border: none; background: #fff; width: 40px; cursor: pointer; font-size: 1.2rem; }
.quantity-select button:hover { background: #f0f0f0; }
.quantity-select input { width: 50px; border: none; text-align: center; font-weight: bold; }

.btn-buy-now { flex: 1; min-width: 160px; background: var(--primary-color); color: white; border: none; padding: 0 30px; height: 48px; border-radius: 8px; font-weight: bold; cursor: pointer; font-size: 1rem; transition: background 0.3s ease; }
.btn-buy-now:hover { background: var(--primary-hover); }
.btn-add-cart-outline { background: #fff; border: 2px solid var(--primary-color); color: var(--primary-color); padding: 0 20px; height: 48px; border-radius: 8px; font-weight: bold; cursor: pointer; }

.tabs-container { padding: 40px 8%; background: #fff; }
.tab-headers { display: flex; gap: 30px; border-bottom: 2px solid #eee; margin-bottom: 25px; flex-wrap: wrap; }
.tab-item { padding-bottom: 10px; font-weight: bold; cursor: pointer; color: #95a5a6; position: relative; }
.tab-item.active { color: var(--primary-color); }
.tab-item.active::after { content: ''; position: absolute; bottom: -2px; left: 0; width: 100%; height: 2px; background: var(--primary-color); }
.tab-panel { display: none; }
.tab-panel.active { display: block; }

.tech-section { border-radius: 10px; background: #f9fafb; border: 1px solid #eef2f7; margin-bottom: 15px; }
.tech-section-title { display: flex; align-items: center; gap: 10px; padding: 12px 15px; font-weight: 800; font-size: 13px; text-transform: uppercase; color: var(--accent-color); background: #f1fbf6; }
.tech-row { display: flex; justify-content: space-between; padding: 10px 15px; border-bottom: 1px solid #eee; gap: 12px; flex-wrap: wrap; }
.tech-label { color: #6b7280; font-weight: 600; }
.tech-value { font-weight: 800; }
.tech-boolean-yes .tech-value { color: var(--primary-color); }
.tech-boolean-no .tech-value { color: #c7c7c7; }

footer { text-align: center; padding: 40px 8%; background: var(--dark-color); color: white; }
footer h3 { margin-top: 0; color: var(--primary-color); }

@media (max-width: 768px) {
    .product-container { grid-template-columns: 1fr; padding: 20px; }
    header nav { display: none; }
    .purchase-zone { flex-direction: column; align-items: stretch; gap: 15px; }
    .btn-buy-now { 
        width: 100%; 
        padding: 22px 30px; 
        font-size: 1.3rem; 
        font-weight: 700;
        border-radius: 12px;
        box-shadow: 0 4px 15px rgba(39, 174, 96, 0.3);
    }
}