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

    body {
        text-align: center;
        padding: 40px;
        background: linear-gradient(90deg, #1e2c2f, #4f8896, #1e2c2f);
        color: white;
    }

    main {
        display: flex;
        flex-direction: column;
        flex-wrap: wrap;
        align-items: center;
        gap: 30px;
    }

    h1 {
        font-size: 40px;
        letter-spacing: 2px;
    }

    #piano {
        display: flex;
        flex-wrap: wrap;
        justify-content: center;
        align-items: center;
        gap: 8px;
        padding: 20px;
        background: #222;
        border-radius: 15px;
        box-shadow: 0 0 20px #0007;
        overflow-x: auto;
    }

    .key {
        width: 70px;
        height: 260px;
        background: white;
        border: none;
        border-radius: 10px;
        font-size: 22px;
        font-weight: bold;
        cursor: pointer;
        transition: 0.1s;
        box-shadow: 0 6px 15px rgba(0, 0, 0, 0.4);
        display: flex;
        justify-content: center;
        align-items: flex-end;
        padding-bottom: 10px;
        user-select: none;
    }

    .key.active {
        background: #ffd54f;
        box-shadow: 0 3px 8px rgba(0, 0, 0, 0.6);
        transform: translateY(3px);
    }

    @media (max-width: 500px) {
        h1 {
            font-size: 28px;
        }

        p {
            font-size: 14px;
            opacity: 0.8;
        }

        .key {
            width: 2rem;
            height: 35vw;
            font-size: 16px;
        }
    }