:root {
    --primary-color: #3498db;
    --secondary-color: #2ecc71;
    --text-color: #333;
    --background-color: #f4f4f4;
}

body {
    font-family: 'Arial', sans-serif;
    line-height: 1.6;
    color: var(--text-color);
    background-color: var(--background-color);
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 15px;
}

.btn {
    display: inline-block;
    padding: 10px 20px;
    background-color: var(--primary-color);
    color: white;
    text-decoration: none;
    border-radius: 5px;
}

.alert {
    padding: 15px;
    margin-bottom: 20px;
    border: 1px solid transparent;
    border-radius: 4px;
}

.alert-danger {
    color: #721c24;
    background-color: #f8d7da;
    border-color: #f5c6cb;
}