* {
    box-sizing: border-box;
}

body {
    margin: 0;
    font-family: system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
    background: #f5f5f5;
    color: #222;
}

header {
    padding: 1rem 1.5rem;
    background: #1f2937;
    color: #fff;
}

header h1 {
    margin: 0;
    font-size: 1.25rem;
}

main {
    padding: 1.5rem;
}