body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background-color: #f5f5f5;
    margin: 0;
    padding: 0;
}

.login-container {
    max-width: 400px;
    margin: 100px auto;
    padding: 20px;
    background: white;
    border-radius: 8px;
    box-shadow: 0 0 10px rgba(0, 0, 0, 0.1);
}

.login-header {
    text-align: center;
    margin-bottom: 20px;
    color: #2c3e50;
}

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

.form-group label {
    display: block;
    margin-bottom: 5px;
    font-weight: 600;
}

.form-control {
    width: 100%;
    padding: 10px;
    border: 1px solid #ddd;
    border-radius: 4px;
    box-sizing: border-box;
}

.btn {
    width: 100%;
    padding: 10px;
    background-color: #3498db;
    color: white;
    border: none;
    border-radius: 4px;
    cursor: pointer;
    font-size: 16px;
}

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

.error-message {
    color: #e74c3c;
    margin-bottom: 15px;
    padding: 10px;
    background-color: #fadbd8;
    border-radius: 4px;
    text-align: center;
}

.register-link {
    text-align: center;
    margin-top: 15px;
}

.register-link a {
    color: #3498db;
    text-decoration: none;
}

.register-link a:hover {
    text-decoration: underline;
}
.sidebar {
    height: 100vh;
    width: 280px;
    position: fixed;
    left: 0;
    top: 0;
    padding: 20px;
    background: #f8f9fa;
    border-right: 1px solid #dee2e6;
}

.main-content {
    margin-left: 280px;
    padding: 20px;
}

.nav-link {
    color: white;
    padding: 8px 16px;
    margin: 4px 0;
    border-radius: 4px;
}

.nav-link:hover {
    background-color: grey;
}

.nav-link.active {
    background-color: #0d6efd;
    color: white;
}

.nav-link i {
    margin-right: 10px;
}