/* University Timetable System - Stylesheet */

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

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

.container {
    max-width: 1400px;
    margin: 0 auto;
    padding: 20px;
}

header {
    background-color: #2c3e50;
    color: white;
    padding: 20px;
    border-radius: 8px;
    margin-bottom: 30px;
}

header h1 {
    margin-bottom: 15px;
}

nav ul {
    list-style: none;
    display: flex;
    gap: 20px;
}

nav ul li a {
    color: white;
    text-decoration: none;
    padding: 8px 16px;
    border-radius: 4px;
    transition: background-color 0.3s;
}

nav ul li a:hover, nav ul li a.active {
    background-color: #34495e;
}

main {
    background-color: white;
    padding: 30px;
    border-radius: 8px;
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
}

.stats-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 20px;
    margin-bottom: 30px;
}

.stat-card {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    padding: 20px;
    border-radius: 8px;
    text-align: center;
}

.stat-number {
    font-size: 2.5em;
    font-weight: bold;
    margin-top: 10px;
}

.btn {
    padding: 12px 24px;
    border: none;
    border-radius: 4px;
    cursor: pointer;
    text-decoration: none;
    display: inline-block;
    font-size: 16px;
    transition: all 0.3s;
}

.btn-primary {
    background-color: #3498db;
    color: white;
}

.btn-success {
    background-color: #2ecc71;
    color: white;
}

.btn-info {
    background-color: #1abc9c;
    color: white;
}

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

table {
    width: 100%;
    border-collapse: collapse;
    margin-top: 20px;
}

table th, table td {
    padding: 12px;
    text-align: left;
    border-bottom: 1px solid #ddd;
}

table th {
    background-color: #34495e;
    color: white;
}

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

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

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

footer {
    text-align: center;
    margin-top: 30px;
    padding: 20px;
    color: #7f8c8d;
}