* { margin: 0; padding: 0; box-sizing: border-box; }

:root {
    --bg: #0d1117;
    --surface: #161b22;
    --border: #21262d;
    --text: #e6edf3;
    --muted: #8b949e;
    --accent: #00d4aa;
    --accent-hover: #00b892;
    --accent-gradient: linear-gradient(135deg, #00d4aa, #00b892);
    --danger: #f85149;
    --card: #161b22;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    background: var(--bg);
    color: var(--text);
    min-height: 100vh;
}

/* Header */
.header {
    background: var(--surface);
    border-bottom: 1px solid var(--border);
    padding: 1.25rem 1.5rem;
    position: sticky;
    top: 0;
    z-index: 100;
}
.header-content {
    max-width: 1200px;
    margin: 0 auto;
    display: flex;
    align-items: center;
    gap: 1rem;
    flex-wrap: wrap;
}
.logo {
    font-size: 1.6rem;
    font-weight: 800;
    letter-spacing: 2px;
    color: #fff;
}
.logo-highlight {
    background: var(--accent-gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}
.tagline {
    color: var(--muted);
    font-size: 0.85rem;
    flex: 1;
}
.cart-btn {
    background: var(--accent-gradient);
    color: #000;
    border: none;
    padding: 0.6rem 1.2rem;
    border-radius: 10px;
    font-weight: 700;
    font-size: 0.95rem;
    cursor: pointer;
    transition: opacity 0.2s;
}
.cart-btn:hover { opacity: 0.85; }

/* Tabs */
.tabs {
    display: flex;
    gap: 0;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 1.5rem;
    border-bottom: 1px solid var(--border);
}
.tab {
    flex: 1;
    padding: 1rem;
    background: none;
    border: none;
    color: var(--muted);
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    border-bottom: 3px solid transparent;
    transition: all 0.2s;
}
.tab.active {
    color: var(--accent);
    border-bottom-color: var(--accent);
}
.tab:hover { color: var(--text); }
.tab:focus { outline: none; }
.sub-tab:focus { outline: none; }

/* Sub-tabs */
.sub-tabs {
    display: flex;
    gap: 0.5rem;
    padding: 1rem 1.5rem;
    max-width: 1200px;
    margin: 0 auto;
    flex-wrap: wrap;
    justify-content: center;
}
.sub-tab {
    padding: 0.5rem 1.2rem;
    background: var(--surface);
    border: 1px solid var(--border);
    color: var(--muted);
    border-radius: 20px;
    font-size: 0.9rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.2s;
}
.sub-tab.active {
    background: var(--accent-gradient);
    color: #000;
    border-color: transparent;
}
.sub-tab:hover:not(.active) { border-color: var(--accent); color: var(--text); }

/* Disclaimer */
.disclaimer {
    max-width: 1200px;
    margin: 0.75rem auto;
    padding: 0.6rem 1.5rem;
    color: var(--muted);
    font-size: 0.8rem;
    text-align: center;
}

/* Tab Content */
.tab-content { display: none; }
.tab-content.active { display: block; }
.sub-content { display: none; }
.sub-content.active { display: block; }

/* Product Grid */
.product-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
    gap: 1.25rem;
    max-width: 1200px;
    margin: 0 auto;
    padding: 1rem 1.5rem 2rem;
}

/* Product Card */
.product-card {
    background: var(--card);
    border: 1px solid var(--border);
    border-radius: 14px;
    overflow: hidden;
    transition: transform 0.2s, border-color 0.2s;
}
.product-card:hover {
    transform: translateY(-3px);
    border-color: var(--accent);
}
.product-img {
    width: 100%;
    height: 220px;
    object-fit: contain;
    background: #fff;
    padding: 1rem;
}
.product-info {
    padding: 1rem;
}
.product-name {
    font-size: 1rem;
    font-weight: 700;
    margin-bottom: 0.25rem;
}
.product-specs {
    color: var(--muted);
    font-size: 0.8rem;
    margin-bottom: 0.5rem;
    line-height: 1.4;
}
.product-price {
    font-size: 1.2rem;
    font-weight: 800;
    color: var(--accent);
    margin-bottom: 0.75rem;
}
.product-stock {
    font-size: 0.75rem;
    color: var(--muted);
    margin-bottom: 0.5rem;
}
.product-stock.low { color: #f0883e; }
.product-stock.out { color: var(--danger); }
.add-btn {
    width: 100%;
    padding: 0.7rem;
    background: var(--accent-gradient);
    color: #000;
    border: none;
    border-radius: 10px;
    font-weight: 700;
    font-size: 0.9rem;
    cursor: pointer;
    transition: opacity 0.2s;
}
.add-btn:hover { opacity: 0.85; }
.add-btn.in-cart {
    background: var(--border);
    color: var(--text);
}
.add-btn:disabled {
    background: var(--border);
    color: var(--muted);
    cursor: not-allowed;
}

/* Cart Sidebar */
.cart-overlay {
    display: none;
    position: fixed;
    top: 0; left: 0;
    width: 100%; height: 100%;
    background: rgba(0,0,0,0.6);
    z-index: 200;
}
.cart-overlay.open { display: block; }
.cart-sidebar {
    position: fixed;
    top: 0; right: -400px;
    width: 380px;
    max-width: 90vw;
    height: 100%;
    background: var(--surface);
    border-left: 1px solid var(--border);
    z-index: 201;
    display: flex;
    flex-direction: column;
    transition: right 0.3s ease;
}
.cart-sidebar.open { right: 0; }
.cart-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1.25rem;
    border-bottom: 1px solid var(--border);
}
.cart-header h2 { font-size: 1.2rem; }
.close-cart {
    background: none;
    border: none;
    color: var(--muted);
    font-size: 1.5rem;
    cursor: pointer;
}
.cart-items {
    flex: 1;
    overflow-y: auto;
    padding: 1rem;
}
.empty-cart {
    text-align: center;
    color: var(--muted);
    padding: 2rem 0;
}
.cart-item {
    display: flex;
    gap: 0.75rem;
    padding: 0.75rem 0;
    border-bottom: 1px solid var(--border);
    align-items: center;
}
.cart-item-img {
    width: 55px;
    height: 55px;
    object-fit: contain;
    background: #fff;
    border-radius: 8px;
    padding: 4px;
}
.cart-item-info { flex: 1; }
.cart-item-name { font-size: 0.85rem; font-weight: 600; }
.cart-item-price { font-size: 0.85rem; color: var(--accent); font-weight: 700; }
.cart-item-qty {
    display: flex;
    align-items: center;
    gap: 0.4rem;
    margin-top: 0.3rem;
}
.qty-btn {
    width: 26px; height: 26px;
    background: var(--border);
    border: none;
    color: var(--text);
    border-radius: 6px;
    font-size: 1rem;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
}
.qty-btn:hover { background: var(--accent); color: #000; }
.qty-val { font-size: 0.85rem; font-weight: 600; min-width: 20px; text-align: center; }
.remove-item {
    background: none;
    border: none;
    color: var(--danger);
    font-size: 1.1rem;
    cursor: pointer;
}
.cart-footer {
    padding: 1.25rem;
    border-top: 1px solid var(--border);
}
.cart-total {
    display: flex;
    justify-content: space-between;
    font-size: 1.1rem;
    font-weight: 700;
    margin-bottom: 1rem;
}
.checkout-btn {
    width: 100%;
    padding: 0.85rem;
    background: var(--accent-gradient);
    color: #000;
    border: none;
    border-radius: 10px;
    font-weight: 700;
    font-size: 1rem;
    cursor: pointer;
}
.checkout-btn:hover { opacity: 0.85; }

/* Checkout Modal */
.modal-overlay {
    position: fixed;
    top: 0; left: 0;
    width: 100%; height: 100%;
    background: rgba(0,0,0,0.7);
    z-index: 300;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 1rem;
}
.modal {
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: 16px;
    padding: 2rem;
    max-width: 450px;
    width: 100%;
    position: relative;
}
.modal-close {
    position: absolute;
    top: 1rem; right: 1rem;
    background: none;
    border: none;
    color: var(--muted);
    font-size: 1.3rem;
    cursor: pointer;
}
.modal h2 { margin-bottom: 1.25rem; }
.modal input {
    width: 100%;
    padding: 0.75rem;
    background: var(--bg);
    border: 1px solid var(--border);
    border-radius: 10px;
    color: var(--text);
    font-size: 0.95rem;
    margin-bottom: 0.75rem;
}
.modal input:focus { outline: none; border-color: var(--accent); }
.order-summary {
    background: var(--bg);
    border-radius: 10px;
    padding: 1rem;
    margin: 0.75rem 0 1rem;
    font-size: 0.85rem;
    max-height: 200px;
    overflow-y: auto;
}
.order-line {
    display: flex;
    justify-content: space-between;
    padding: 0.3rem 0;
}
.order-line.total {
    border-top: 1px solid var(--border);
    margin-top: 0.5rem;
    padding-top: 0.5rem;
    font-weight: 700;
    font-size: 1rem;
}
.pay-btn {
    width: 100%;
    padding: 0.85rem;
    background: var(--accent-gradient);
    color: #000;
    border: none;
    border-radius: 10px;
    font-weight: 700;
    font-size: 1rem;
    cursor: pointer;
}
.pay-btn:hover { opacity: 0.85; }
.sandbox-notice {
    text-align: center;
    color: #f0883e;
    font-size: 0.75rem;
    margin-top: 0.75rem;
}

/* Footer */
.footer {
    text-align: center;
    padding: 2rem 1.5rem;
    color: var(--muted);
    font-size: 0.8rem;
    border-top: 1px solid var(--border);
    margin-top: 2rem;
}
.footer-disclaimer { font-size: 0.7rem; margin-top: 0.5rem; }

/* ===== FLOATING CART (mobile) ===== */
.floating-cart {
    display: none;
    position: fixed;
    bottom: 1.5rem;
    right: 1.5rem;
    background: var(--surface);
    color: var(--text);
    border: 1px solid var(--border);
    padding: 0.85rem 1.3rem;
    border-radius: 50px;
    font-size: 1rem;
    font-weight: 700;
    cursor: pointer;
    box-shadow: 0 4px 15px rgba(0,0,0,0.3);
    z-index: 999;
    transition: transform 0.3s, background 0.3s;
}
.floating-cart:hover { transform: scale(1.05); }

/* Responsive */
@media (max-width: 600px) {
    .header { padding: 0.75rem 1rem; }
    .header-content { justify-content: space-between; text-align: left; flex-wrap: nowrap; }
    .logo { font-size: 1.3rem; }
    .tagline { display: none; }
    .cart-btn { display: none; }
    .floating-cart { display: block; }
    .theme-btn { width: 36px; height: 36px; font-size: 1rem; }
    .tabs { padding: 0; }
    .tab { padding: 0.75rem 0.5rem; font-size: 0.85rem; }
    .disclaimer { font-size: 0.7rem; padding: 0.5rem 1rem; }
    .sub-tabs { padding: 0.5rem 0.75rem; gap: 0.4rem; }
    .sub-tab { padding: 0.4rem 0.9rem; font-size: 0.8rem; }
    .product-grid { grid-template-columns: repeat(2, 1fr); gap: 0.6rem; padding: 0.6rem; }
    .product-img { height: 140px; padding: 0.5rem; }
    .product-info { padding: 0.6rem; }
    .product-name { font-size: 0.85rem; }
    .product-specs { font-size: 0.7rem; }
    .product-price { font-size: 1rem; margin-bottom: 0.4rem; }
    .product-stock { font-size: 0.7rem; }
    .add-btn { padding: 0.55rem; font-size: 0.8rem; }
    .footer { padding: 1.5rem 1rem; margin-bottom: 4rem; }
    .footer-disclaimer { font-size: 0.65rem; }
}

/* ===== THEME TOGGLE ===== */
.theme-btn {
    background: var(--card);
    border: 1px solid var(--border);
    color: var(--text);
    width: 40px;
    height: 40px;
    border-radius: 10px;
    font-size: 1.1rem;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all 0.2s;
}
.theme-btn:hover { border-color: var(--accent); }

/* ===== LIGHT THEME ===== */
[data-theme="light"] {
    --bg: #f5f7fa;
    --surface: #ffffff;
    --border: #dde3ea;
    --text: #1a1a2e;
    --muted: #555;
    --accent: #22c55e;
    --accent-hover: #16a34a;
    --accent-gradient: linear-gradient(135deg, #22c55e, #16a34a);
    --danger: #dc2626;
    --card: #ffffff;
}
[data-theme="light"] body { background: var(--bg); color: var(--text); }
[data-theme="light"] .header { background: #2c3e50; }
[data-theme="light"] .header .tagline { color: #94a3b8; }
[data-theme="light"] .header .logo { color: #fff; }
[data-theme="light"] .header .logo-highlight { background: linear-gradient(135deg, #22c55e, #16a34a); -webkit-background-clip: text; -webkit-text-fill-color: transparent; background-clip: text; }
[data-theme="light"] .tabs { border-bottom-color: var(--border); }
[data-theme="light"] .tab { color: #666; }
[data-theme="light"] .tab.active { color: #2c3e50; border-bottom-color: #2c3e50; }
[data-theme="light"] .tab:hover { color: var(--text); }
[data-theme="light"] .sub-tab { background: #eef2f7; border-color: var(--border); color: #666; }
[data-theme="light"] .sub-tab.active { background: #2c3e50; color: #fff; border-color: #2c3e50; }
[data-theme="light"] .sub-tab:hover:not(.active) { border-color: #2c3e50; color: var(--text); }
[data-theme="light"] .product-card { background: #fff; border-color: var(--border); }
[data-theme="light"] .product-card:hover { border-color: #22c55e; box-shadow: 0 8px 25px rgba(22,163,74,0.1); }
[data-theme="light"] .product-name { color: var(--text); }
[data-theme="light"] .product-specs { color: #666; }
[data-theme="light"] .product-price { color: #2c3e50; }
[data-theme="light"] .product-img { background: #f8f9fa; }
[data-theme="light"] .add-btn { background: #2c3e50; color: #fff; }
[data-theme="light"] .add-btn:hover { background: #16a34a; }
[data-theme="light"] .add-btn.in-cart { background: #2c3e50; color: #22c55e; }
[data-theme="light"] .add-btn:disabled { background: #e2e8f0; color: #999; }
[data-theme="light"] .cart-sidebar { background: #fff; border-left-color: var(--border); }
[data-theme="light"] .cart-header { border-bottom-color: var(--border); }
[data-theme="light"] .cart-footer { border-top-color: var(--border); }
[data-theme="light"] .cart-item { border-bottom-color: var(--border); }
[data-theme="light"] .cart-item-img { background: #f8f9fa; }
[data-theme="light"] .qty-btn { background: #eef2f7; color: var(--text); }
[data-theme="light"] .qty-btn:hover { background: #16a34a; color: #fff; }
[data-theme="light"] .checkout-btn { background: #2c3e50; color: #fff; }
[data-theme="light"] .checkout-btn:hover { background: #16a34a; }
[data-theme="light"] .modal { background: #fff; border-color: var(--border); }
[data-theme="light"] .modal input { background: #f5f7fa; border-color: var(--border); color: var(--text); }
[data-theme="light"] .modal input:focus { border-color: #22c55e; }
[data-theme="light"] .order-summary { background: #f5f7fa; }
[data-theme="light"] .pay-btn { background: #2c3e50; color: #fff; }
[data-theme="light"] .pay-btn:hover { background: #16a34a; }
[data-theme="light"] .footer { background: #2c3e50; color: #fff; border-top-color: #34495e; }
[data-theme="light"] .disclaimer { color: #888; }
[data-theme="light"] .cart-btn { background: #2c3e50; color: #fff; }
[data-theme="light"] .cart-btn:hover { background: #16a34a; }
[data-theme="light"] .theme-btn { background: #eef2f7; border-color: var(--border); color: var(--text); }