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

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
    background: #f5f5f5;
    color: #333;
}

.header {
    background: #2c3e50;
    color: white;
    padding: 1rem 2rem;
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
}

.header h1 {
    font-size: 1.5rem;
}

.nav {
    background: #34495e;
    padding: 0.5rem 2rem;
}

.nav a {
    color: white;
    text-decoration: none;
    margin-right: 2rem;
    padding: 0.5rem 1rem;
    display: inline-block;
    border-radius: 4px;
    transition: background 0.2s;
}

.nav a:hover, .nav a.active {
    background: #2c3e50;
}

.container {
    max-width: 100%;
    padding: 2rem;
}

.btn {
    padding: 0.5rem 1rem;
    border: none;
    border-radius: 4px;
    cursor: pointer;
    font-size: 0.9rem;
    transition: all 0.2s;
}

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

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

.btn-success {
    background: #27ae60;
    color: white;
}

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