:root {
    --color-bg: #f6f7f9;
    --color-surface: #ffffff;
    --color-border: #e2e5ea;
    --color-text: #1f2430;
    --color-muted: #6b7280;
    --color-primary: #2f6fed;
    --color-primary-dark: #244fb0;
    --color-danger: #d64545;
    --radius: 8px;
}

* {
    box-sizing: border-box;
}

body {
    margin: 0;
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
    background: var(--color-bg);
    color: var(--color-text);
    display: flex;
    flex-direction: column;
    min-height: 100vh;
}

.container {
    width: 100%;
    max-width: 1080px;
    margin: 0 auto;
    padding: 0 20px;
}

.site-header {
    background: var(--color-surface);
    border-bottom: 1px solid var(--color-border);
}

.header-inner {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 16px 20px;
}

.brand {
    font-weight: 700;
    font-size: 1.25rem;
    color: var(--color-text);
    text-decoration: none;
}

.main-nav {
    display: flex;
    align-items: center;
    gap: 20px;
}

.main-nav a {
    color: var(--color-text);
    text-decoration: none;
    font-weight: 500;
}

.main-nav a:hover {
    color: var(--color-primary);
}

.cart-link {
    display: inline-flex;
    align-items: center;
    gap: 6px;
}

.cart-count {
    background: var(--color-primary);
    color: #fff;
    font-size: 0.75rem;
    font-weight: 700;
    padding: 2px 7px;
    border-radius: 999px;
}

.page {
    flex: 1;
    padding: 32px 20px 48px;
}

.alert {
    background: #eaf2ff;
    border: 1px solid #c6dbff;
    color: var(--color-primary-dark);
    padding: 12px 16px;
    border-radius: var(--radius);
    margin-bottom: 24px;
}

.alert-errors {
    background: #fdecec;
    border: 1px solid #f6c4c4;
    color: var(--color-danger);
    padding: 12px 16px;
    border-radius: var(--radius);
    margin-bottom: 24px;
}

.alert-errors ul {
    margin: 0;
    padding-left: 18px;
}

h1 {
    font-size: 1.75rem;
    margin: 0 0 24px;
}

h2 {
    font-size: 1.25rem;
    margin: 0 0 12px;
}

.product-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(220px, 1fr));
    gap: 20px;
}

.card {
    background: var(--color-surface);
    border: 1px solid var(--color-border);
    border-radius: var(--radius);
    overflow: hidden;
    display: flex;
    flex-direction: column;
}

.placeholder-img {
    background: linear-gradient(135deg, #e9edf5, #dbe2ee);
    color: var(--color-muted);
    height: 160px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 600;
    letter-spacing: 0.03em;
    text-transform: uppercase;
    font-size: 0.85rem;
}

.card-body {
    padding: 16px;
    display: flex;
    flex-direction: column;
    gap: 8px;
    flex: 1;
}

.card-title {
    font-weight: 600;
    font-size: 1rem;
}

.card-title a {
    color: var(--color-text);
    text-decoration: none;
}

.card-title a:hover {
    color: var(--color-primary);
}

.card-desc {
    color: var(--color-muted);
    font-size: 0.875rem;
    flex: 1;
}

.price {
    font-weight: 700;
    font-size: 1.1rem;
}

.btn {
    display: inline-block;
    background: var(--color-primary);
    color: #fff;
    border: none;
    padding: 10px 16px;
    border-radius: var(--radius);
    font-size: 0.9rem;
    font-weight: 600;
    cursor: pointer;
    text-decoration: none;
    text-align: center;
}

.btn:hover {
    background: var(--color-primary-dark);
}

.btn-secondary {
    background: var(--color-surface);
    color: var(--color-text);
    border: 1px solid var(--color-border);
}

.btn-secondary:hover {
    background: #f0f1f3;
}

.btn-danger {
    background: var(--color-surface);
    color: var(--color-danger);
    border: 1px solid #f2c4c4;
}

.btn-danger:hover {
    background: #fdecec;
}

.btn-block {
    display: block;
    width: 100%;
}

.product-detail {
    display: grid;
    grid-template-columns: 320px 1fr;
    gap: 32px;
}

@media (max-width: 640px) {
    .product-detail {
        grid-template-columns: 1fr;
    }
}

.product-detail .placeholder-img {
    height: 280px;
    border-radius: var(--radius);
}

.qty-form {
    display: flex;
    align-items: center;
    gap: 10px;
    margin: 16px 0;
}

.qty-form input[type="number"] {
    width: 70px;
    padding: 8px;
    border: 1px solid var(--color-border);
    border-radius: var(--radius);
}

table.cart-table {
    width: 100%;
    border-collapse: collapse;
    background: var(--color-surface);
    border: 1px solid var(--color-border);
    border-radius: var(--radius);
    overflow: hidden;
}

table.cart-table th,
table.cart-table td {
    padding: 12px 16px;
    text-align: left;
    border-bottom: 1px solid var(--color-border);
    vertical-align: middle;
}

table.cart-table tr:last-child td {
    border-bottom: none;
}

.cart-item-name {
    font-weight: 600;
}

.cart-actions {
    display: flex;
    align-items: center;
    gap: 8px;
}

.cart-actions input[type="number"] {
    width: 60px;
    padding: 6px;
    border: 1px solid var(--color-border);
    border-radius: var(--radius);
}

.cart-summary {
    margin-top: 20px;
    display: flex;
    justify-content: flex-end;
}

.cart-summary-box {
    background: var(--color-surface);
    border: 1px solid var(--color-border);
    border-radius: var(--radius);
    padding: 20px;
    width: 280px;
}

.cart-summary-box .total-row {
    display: flex;
    justify-content: space-between;
    font-weight: 700;
    font-size: 1.1rem;
    margin-bottom: 16px;
}

.empty-state {
    background: var(--color-surface);
    border: 1px dashed var(--color-border);
    border-radius: var(--radius);
    padding: 40px;
    text-align: center;
    color: var(--color-muted);
}

.checkout-layout {
    display: grid;
    grid-template-columns: 1fr 320px;
    gap: 32px;
    align-items: start;
}

@media (max-width: 780px) {
    .checkout-layout {
        grid-template-columns: 1fr;
    }
}

.form-group {
    margin-bottom: 16px;
}

.form-group label {
    display: block;
    font-weight: 600;
    margin-bottom: 6px;
    font-size: 0.9rem;
}

.form-group input,
.form-group textarea {
    width: 100%;
    padding: 10px 12px;
    border: 1px solid var(--color-border);
    border-radius: var(--radius);
    font-family: inherit;
    font-size: 0.95rem;
}

.form-group textarea {
    min-height: 90px;
    resize: vertical;
}

.radio-option {
    display: flex;
    align-items: center;
    gap: 8px;
    font-weight: 400;
    margin-bottom: 8px;
}

.radio-option input {
    width: auto;
}

.order-summary {
    background: var(--color-surface);
    border: 1px solid var(--color-border);
    border-radius: var(--radius);
    padding: 20px;
}

.order-summary ul {
    list-style: none;
    margin: 0 0 16px;
    padding: 0;
}

.order-summary li {
    display: flex;
    justify-content: space-between;
    padding: 8px 0;
    border-bottom: 1px solid var(--color-border);
    font-size: 0.9rem;
}

.order-summary li:last-child {
    border-bottom: none;
}

.order-summary .total-row {
    display: flex;
    justify-content: space-between;
    font-weight: 700;
    padding-top: 8px;
    border-top: 2px solid var(--color-border);
}

.payment-box {
    background: var(--color-surface);
    border: 1px solid var(--color-border);
    border-radius: var(--radius);
    padding: 40px;
    text-align: center;
    max-width: 420px;
    margin: 0 auto;
}

.qr-image {
    width: 220px;
    height: 220px;
    margin: 20px auto;
    display: block;
}

.qr-placeholder {
    width: 220px;
    height: 220px;
    margin: 20px auto;
    border: 2px dashed var(--color-border);
    border-radius: var(--radius);
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--color-muted);
    font-size: 0.9rem;
    padding: 16px;
}

.badge {
    display: inline-block;
    padding: 4px 10px;
    border-radius: 999px;
    font-size: 0.75rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.03em;
    background: #fff3cd;
    color: #8a6d1a;
}

.badge-success {
    background: #d7f3e0;
    color: #1c7a41;
}

.badge-failed {
    background: #fdecec;
    color: #b3261e;
}

.site-footer {
    border-top: 1px solid var(--color-border);
    padding: 20px 0;
    color: var(--color-muted);
    font-size: 0.85rem;
}