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

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
    overflow: hidden;
}

header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    background: #2c3e50;
    color: white;
    padding: 1rem 2rem;
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
    z-index: 1000;
}

nav {
    display: flex;
    gap: 2rem;
    align-items: center;
}

.logo {
    font-size: 1.5rem;
    font-weight: bold;
    margin-right: auto;
}

nav a {
    color: white;
    text-decoration: none;
    padding: 0.5rem 1rem;
    border-radius: 4px;
    transition: background 0.2s;
}

nav a:hover {
    background: rgba(255,255,255,0.1);
}

nav a.active {
    background: rgba(255,255,255,0.2);
}

#app-frame {
    position: fixed;
    top: 88px; /* Height of header */
    left: 0;
    width: 100vw;
    height: calc(100vh - 88px);
    border: none;
    background: white;
}