* {
    box-sizing: border-box;
}

body {
    margin: 0;
    font-family: system-ui, -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    background: #fafafa;
    color: #222;
}

a {
    color: #0a7acc;
    text-decoration: none;
}

a:hover {
    text-decoration: underline;
}

.container {
    width: 100%;
    max-width: 1080px;
    margin: 0 auto;
    padding: 0 16px;
}

.site-header {
    background: #111;
    color: #fff;
}

.site-header .container {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 12px 16px;
}

.logo a {
    font-weight: 700;
    font-size: 20px;
    color: #fff;
}

.site-header nav a {
    margin-left: 16px;
    color: #eee;
}

.site-footer {
    margin-top: 40px;
    padding: 24px 0;
    background: #111;
    color: #aaa;
}

.product-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
    gap: 20px;
    margin-top: 24px;
}

.product-card {
    background: #fff;
    border-radius: 8px;
    padding: 16px;
    box-shadow: 0 2px 6px rgba(0,0,0,.06);
}

.product-card h3 {
    margin-top: 0;
}

.product-card .price {
    font-weight: 700;
    color: #0a7acc;
}

.product-card form {
    margin-top: 12px;
}

input[type="text"],
input[type="number"],
input[type="email"],
input[type="password"] {
    width: 100%;
    padding: 8px 10px;
    border-radius: 4px;
    border: 1px solid #ccc;
    margin-top: 4px;
    margin-bottom: 10px;
}

button,
.btn {
    display: inline-block;
    border: none;
    border-radius: 4px;
    padding: 8px 14px;
    background: #0a7acc;
    color: #fff;
    cursor: pointer;
}

button:hover,
.btn:hover {
    background: #075b94;
    text-decoration: none;
}

.cart-table,
.admin-table {
    width: 100%;
    border-collapse: collapse;
    margin-top: 16px;
}

.cart-table th,
.cart-table td,
.admin-table th,
.admin-table td {
    padding: 8px;
    border-bottom: 1px solid #eee;
}

.alert {
    padding: 10px 14px;
    border-radius: 4px;
    margin-bottom: 12px;
}

.alert-error {
    background: #ffe5e5;
    color: #a10000;
}

.checkout-layout {
    display: grid;
    grid-template-columns: 2fr 1fr;
    gap: 40px;
    margin-top: 24px;
}

.checkout-summary {
    list-style: none;
    padding: 0;
    margin: 0;
}

.checkout-summary li {
    display: flex;
    justify-content: space-between;
    padding: 4px 0;
}

.checkout-total {
    margin-top: 10px;
    font-size: 18px;
}

.admin .site-header {
    background: #20232a;
}

.admin body {
    background: #f4f5f7;
}

.login-container {
    max-width: 420px;
    margin-top: 80px;
}

@media (max-width: 768px) {
    .checkout-layout {
        grid-template-columns: 1fr;
    }
}