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

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    min-height: 100vh;
}

/* Sidebar */
.sidebar {
    width: 250px;
    background: #2c3e50;
    color: white;
    position: fixed;
    height: 100%;
    left: 0;
    top: 0;
    transition: all 0.3s;
}

.sidebar-header {
    padding: 20px;
    text-align: center;
    background: #34495e;
}

.sidebar-header h3 {
    font-size: 1.5em;
    margin-bottom: 5px;
}

.sidebar-header p {
    font-size: 0.8em;
    opacity: 0.8;
}

.sidebar-menu {
    list-style: none;
    padding: 0;
    margin-top: 20px;
}

.sidebar-menu li {
    padding: 15px 20px;
    transition: all 0.3s;
}

.sidebar-menu li:hover {
    background: #34495e;
    padding-left: 30px;
}

.sidebar-menu li a {
    color: white;
    text-decoration: none;
    display: flex;
    align-items: center;
    gap: 10px;
}

.sidebar-menu li i {
    width: 25px;
}

/* Main Content */
.main-content {
    margin-left: 250px;
    padding: 20px;
}

/* Header */
.header {
    background: white;
    padding: 20px;
    border-radius: 10px;
    margin-bottom: 20px;
    box-shadow: 0 2px 5px rgba(0,0,0,0.1);
    display: flex;
    justify-content: space-between;
    align-items: center;
}

/* Cards */
.stats-container {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 20px;
    margin-bottom: 30px;
}

.stat-card {
    background: white;
    padding: 20px;
    border-radius: 10px;
    box-shadow: 0 2px 5px rgba(0,0,0,0.1);
    transition: transform 0.3s;
}

.stat-card:hover {
    transform: translateY(-5px);
}

.stat-card h3 {
    color: #666;
    font-size: 0.9em;
    margin-bottom: 10px;
}

.stat-card .value {
    font-size: 2em;
    font-weight: bold;
    color: #2c3e50;
}

/* Tables */
.table-container {
    background: white;
    border-radius: 10px;
    padding: 20px;
    overflow-x: auto;
}

table {
    width: 100%;
    border-collapse: collapse;
}

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

th {
    background: #667eea;
    color: white;
}

tr:hover {
    background: #f5f5f5;
}

/* Forms */
.form-container {
    background: white;
    border-radius: 10px;
    padding: 30px;
    max-width: 600px;
    margin: 0 auto;
}

.form-group {
    margin-bottom: 20px;
}

label {
    display: block;
    margin-bottom: 5px;
    color: #333;
    font-weight: 500;
}

input, select, textarea {
    width: 100%;
    padding: 10px;
    border: 1px solid #ddd;
    border-radius: 5px;
    font-size: 1em;
}

button {
    background: #667eea;
    color: white;
    border: none;
    padding: 12px 30px;
    border-radius: 5px;
    cursor: pointer;
    font-size: 1em;
    transition: background 0.3s;
}

button:hover {
    background: #5a67d8;
}

.btn-danger {
    background: #e74c3c;
}

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

/* Alert Messages */
.alert {
    padding: 15px;
    border-radius: 5px;
    margin-bottom: 20px;
}

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

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

/* Login Page */
.login-container {
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
}

.login-box {
    background: white;
    padding: 40px;
    border-radius: 10px;
    box-shadow: 0 10px 40px rgba(0,0,0,0.2);
    width: 100%;
    max-width: 400px;
}

.login-box h2 {
    text-align: center;
    margin-bottom: 30px;
    color: #333;
}

/* Responsive */
@media (max-width: 768px) {
    .sidebar {
        left: -250px;
    }
    
    .main-content {
        margin-left: 0;
    }
    
    .stats-container {
        grid-template-columns: 1fr;
    }
}