* {
    box-sizing: border-box;
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    margin: 0;
    padding: 0;
}

body {
    background-color: #f4f7f6;
    color: #333;
    padding: 40px 20px;
}

.container {
    max-width: 1100px;
    margin: 0 auto;
    display: flex;
    flex-wrap: wrap;
    gap: 30px;
}

.col-main {
    flex: 2;
    min-width: 320px;
}

.col-side {
    flex: 1;
    min-width: 300px;
}

.card {
    background: #fff;
    padding: 30px;
    border-radius: 8px;
    box-shadow: 0 4px 6px rgba(0,0,0,0.05);
    margin-bottom: 20px;
}

h2, h3 {
    margin-bottom: 20px;
    color: #2c3e50;
    border-bottom: 2px solid #ecf0f1;
    padding-bottom: 10px;
}

.form-group {
    margin-bottom: 15px;
}

.form-row {
    display: flex;
    gap: 15px;
}

.form-row .form-group {
    flex: 1;
}

label {
    display: block;
    margin-bottom: 6px;
    font-weight: 600;
    font-size: 14px;
}

select, input[type="text"], input[type="email"] {
    width: 100%;
    padding: 10px;
    border: 1px solid #ccc;
    border-radius: 4px;
    font-size: 15px;
    transition: border-color 0.3s;
}

input[type="text"]:focus, input[type="email"]:focus {
    border-color: #3498db;
    outline: none;
}

.btn-submit {
    background-color: #2ecc71;
    color: white;
    border: none;
    padding: 15px 20px;
    width: 100%;
    font-size: 16px;
    font-weight: bold;
    border-radius: 4px;
    cursor: pointer;
    transition: background 0.3s;
}

.btn-submit:hover {
    background-color: #27ae60;
}

.cart-item {
    display: flex;
    justify-content: space-between;
    margin-bottom: 12px;
    font-size: 15px;
}

.cart-total {
    display: flex;
    justify-content: space-between;
    margin-top: 15px;
    padding-top: 15px;
    border-top: 2px dashed #eee;
    font-weight: bold;
    font-size: 18px;
    color: #e74c3c;
}

.alert {
    padding: 15px;
    border-radius: 4px;
    margin-bottom: 20px;
    font-weight: 600;
}
.alert-success { background-color: #d4edda; color: #155724; }
.alert-error { background-color: #f8d7da; color: #721c24; }