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

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

/* Login Page */
#login {
    display: flex;
    justify-content: center;
    align-items: center;
    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;
    color: #667eea;
    margin-bottom: 30px;
    font-size: 28px;
}

.login-box input {
    width: 100%;
    padding: 12px;
    margin: 10px 0;
    border: 1px solid #ddd;
    border-radius: 5px;
    font-size: 14px;
}

.login-box button {
    width: 100%;
    padding: 12px;
    background: #667eea;
    color: white;
    border: none;
    border-radius: 5px;
    cursor: pointer;
    font-size: 16px;
    margin-top: 10px;
}

.login-box button:hover {
    background: #5568d3;
}

#loginError {
    color: #dc3545;
    margin-top: 10px;
    text-align: center;
    font-size: 14px;
}

/* Dashboard Layout */
#dashboard {
    display: flex;
    height: 100vh;
}

#sidebar {
    width: 260px;
    background: #2c3e50;
    color: white;
    display: flex;
    flex-direction: column;
    position: fixed;
    height: 100vh;
    overflow-y: auto;
}

.sidebar-header {
    padding: 25px 20px;
    background: #1a252f;
    border-bottom: 1px solid #34495e;
}

.sidebar-header h2 {
    font-size: 24px;
    margin-bottom: 5px;
}

.sidebar-header small {
    color: #95a5a6;
    font-size: 12px;
}

.nav-menu {
    list-style: none;
    flex: 1;
}

.nav-menu li {
    padding: 15px 20px;
    cursor: pointer;
    border-bottom: 1px solid #34495e;
    transition: all 0.3s;
}

.nav-menu li:hover {
    background: #34495e;
    padding-left: 25px;
}

.nav-menu li.active {
    background: #3498db;
    border-left: 4px solid #2980b9;
}

#content {
    margin-left: 260px;
    flex: 1;
    background: #f5f5f5;
}

#contentFrame {
    width: 100%;
    height: 100vh;
    border: none;
}

/* Responsive */
@media (max-width: 768px) {
    #sidebar {
        width: 60px;
    }
    #content {
        margin-left: 60px;
    }
    .sidebar-header h2,
    .sidebar-header small {
        display: none;
    }
    .nav-menu li {
        text-align: center;
        font-size: 20px;
    }
}