:root { --primary: #2d5a27; --accent: #e44d26; --text: #333; }
body { font-family: 'Arial', sans-serif; margin: 0; background: #f4f4f4; color: var(--text); line-height: 1.6; }
.container { width: 90%; max-width: 1200px; margin: auto; }

/* Giữ nguyên Header & Grid cũ của bạn */
header { background: #fff; padding: 15px 0; box-shadow: 0 2px 10px rgba(0,0,0,0.1); position: sticky; top:0; z-index:100; }
header .container { display: flex; justify-content: space-between; align-items: center; }
nav a { text-decoration: none; color: var(--text); font-weight: bold; margin-left: 20px; }

/* CSS MỚI CHO TRANG CHI TIẾT */
.product-detail-wrapper { 
    display: flex; 
    gap: 50px; 
    background: #fff; 
    padding: 40px; 
    border-radius: 15px; 
    margin-top: 30px;
    box-shadow: 0 5px 20px rgba(0,0,0,0.05);
}

.product-image-side { flex: 1; text-align: center; }
.product-image-side img { 
    width: 100%; 
    max-width: 450px; 
    border-radius: 12px; 
    border: 1px solid #eee;
}

.product-info-side { flex: 1; }
.status-tag { color: var(--primary); font-weight: bold; font-size: 0.9rem; margin-bottom: 10px; display: block; }
.product-info-side h1 { margin: 0 0 15px 0; font-size: 2rem; color: var(--text); }
.detail-price { color: var(--accent); font-size: 2.2rem; font-weight: bold; margin-bottom: 20px; }

.product-desc { margin-bottom: 30px; color: #555; font-size: 1.05rem; }

/* Phần chọn số lượng và nút bấm */
.purchase-box { display: flex; gap: 15px; align-items: center; border-top: 1px solid #eee; padding-top: 25px; }
.qty-input { display: flex; border: 1px solid #ddd; border-radius: 5px; overflow: hidden; }
.qty-input button { padding: 10px 15px; border: none; background: #f8f8f8; cursor: pointer; font-size: 1.1rem; }
.qty-input input { width: 45px; text-align: center; border: none; font-weight: bold; }

.btn-large { 
    background: var(--primary); color: #fff; border: none; padding: 15px 40px; 
    border-radius: 5px; cursor: pointer; font-weight: bold; text-transform: uppercase; flex-grow: 1;
}
.btn-large:hover { background: #1e3d1a; }

@media (max-width: 768px) {
    .product-detail-wrapper { flex-direction: column; padding: 20px; }
}