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

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    line-height: 1.6;
    color: #333;
    background-color: #f5f5f5;
}

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

.text-center {
    text-align: center;
}

.mt-20 {
    margin-top: 20px;
}

.mb-20 {
    margin-bottom: 20px;
}

/* Button Styles */
.btn {
    display: inline-block;
    padding: 10px 20px;
    background-color: #3498db;
    color: white;
    text-decoration: none;
    border-radius: 4px;
    border: none;
    cursor: pointer;
    font-size: 16px;
    font-weight: 500;
    transition: background-color 0.3s;
}

.btn:hover {
    background-color: #2980b9;
}

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

.btn-success:hover {
    background-color: #219653;
}

.btn-danger {
    background-color: #e74c3c;
}

.btn-danger:hover {
    background-color: #c0392b;
}

.btn-warning {
    background-color: #f39c12;
}

.btn-warning:hover {
    background-color: #d68910;
}

/* Alert Messages */
.alert {
    padding: 12px 20px;
    border-radius: 4px;
    margin-bottom: 20px;
}

.alert-success {
    background-color: #d4edda;
    color: #155724;
    border: 1px solid #c3e6cb;
}

.alert-danger {
    background-color: #f8d7da;
    color: #721c24;
    border: 1px solid #f5c6cb;
}

.alert-warning {
    background-color: #fff3cd;
    color: #856404;
    border: 1px solid #ffeaa7;
}

.alert-info {
    background-color: #d1ecf1;
    color: #0c5460;
    border: 1px solid #bee5eb;
}