body {
    font-family: 'Segoe UI', 'Hiragino Sans', 'Meiryo', sans-serif;
    background: #f8f9fa;
    margin: 0;
    padding: 0;
}
button, .choice {
    font-size: 1.1em;
    padding: 0.7em 1.2em;
    margin: 0.5em 0;
    border: none;
    border-radius: 8px;
    background: #3498db;
    color: #fff;
    cursor: pointer;
    width: 50%;
    transition: background 0.2s;
}