* {
    box-sizing: border-box;
}

body {
    margin: 0;
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
    background-color: #f8f9fa;
    color: #212529;
    line-height: 1.6;
}

.header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    background-color: #ffffff;
    border-bottom: 1px solid #e9ecef;
    padding: 1rem 2rem;
    z-index: 1000;
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
}

.header h1 {
    margin: 0;
    font-size: 1.5rem;
    font-weight: 600;
}

.header h1 a {
    text-decoration: none;
    color: #495057;
    transition: color 0.2s ease;
}

.header h1 a:hover {
    color: #007bff;
}

.wrapper {
    display: flex;
    margin-top: 80px;
    min-height: calc(100vh - 80px);
}

.hamburger {
    display: none;
    background: none;
    border: none;
    font-size: 1.5rem;
    cursor: pointer;
    color: #495057;
    position: absolute;
    left: 1rem;
    top: 50%;
    transform: translateY(-50%);
}

.sidenav {
    position: fixed;
    top: 80px;
    left: 0;
    width: 240px;
    height: calc(100vh - 80px);
    background-color: #ffffff;
    border-right: 1px solid #e9ecef;
    padding: 1rem 0;
    overflow-y: auto;
    transition: transform 0.3s ease;
}

.content {
    margin-left: 240px;
    padding: 2rem;
    width: calc(100% - 240px);
    overflow-x: hidden;
}

.links {
    display: flex;
    flex-direction: column;
}

.links a {
    padding: 0.875rem 1.5rem;
    text-decoration: none;
    color: #6c757d;
    font-weight: 500;
    transition: all 0.2s ease;
    border-left: 3px solid transparent;
}

.links a:hover {
    background-color: #f8f9fa;
    color: #007bff;
    border-left-color: #007bff;
}

/* Mobile responsiveness */
@media (max-width: 768px) {
    .header {
        padding: 1rem;
    }
    
    .sidenav {
        transform: translateX(-100%);
        width: 280px;
        box-shadow: 2px 0 10px rgba(0,0,0,0.1);
    }
    
    .sidenav.open {
        transform: translateX(0);
    }
    
    .content {
        margin-left: 0;
        width: 100%;
        padding: 1rem;
    }
    .hamburger {
        display: block;
    }
    
    .header h1 {
        text-align: center;
    }
}