html, body {
    margin: 0;
    padding: 0;
    width: 100%;
    height: 100%;
    overflow: hidden;
}
body {
    display: flex;
    justify-content: center;
    align-items: center;

    background-image: url("sprites/bg.png?v=3");
    background-size: cover;
    background-position: center center;
    background-repeat: no-repeat;
    background-attachment: scroll;
}
@media (min-width: 769px) {
    body {
        background-attachment: fixed;
    }
}
canvas {
    display: block;
}

.keys {
    width: 40px;
    height: 40px;

    background: rgba(255, 255, 255, 0.18);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);

    border: 1px solid rgba(0, 0, 0, 0.6);
    border-radius: 10px;

    color: #ffffff;
    font-size: 16px;
    font-weight: 700;

    text-shadow:
        0 0 2px rgba(0, 0, 0, 0.8),
        0 1px 3px rgba(0, 0, 0, 0.8);

    box-shadow:
        0 0 0 1px rgba(0, 0, 0, 0.2),
        0 4px 12px rgba(0, 0, 0, 0.25),
        inset 0 1px 1px rgba(255, 255, 255, 0.25);

    cursor: pointer;
    transition: all 0.15s ease;
}

.keys:hover {
    background: rgba(255, 255, 255, 0.28);
    transform: translateY(-2px);

    box-shadow:
        0 0 0 1px rgba(0, 0, 0, 0.3),
        0 8px 20px rgba(0, 0, 0, 0.3),
        inset 0 1px 1px rgba(255, 255, 255, 0.3);
}

.keys:active {
    transform: translateY(1px);

    box-shadow:
        0 0 0 1px rgba(0, 0, 0, 0.2),
        0 2px 6px rgba(0, 0, 0, 0.25),
        inset 0 2px 4px rgba(0, 0, 0, 0.15);
}

.keys:disabled {
    background: rgba(100, 100, 100, 0.25);
    color: rgba(255, 255, 255, 0.55);
    border-color: rgba(0, 0, 0, 0.2);

    cursor: not-allowed;
    transform: none;
    box-shadow: none;
}

.hint-button {
    width: 60px;
    height: 40px;

    background: rgba(255, 255, 255, 0.18);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);

    border: 1px solid rgba(0, 0, 0, 0.6);
    border-radius: 10px;

    color: #ffffff;
    font-size: 14px;
    font-weight: 700;

    text-shadow:
        0 0 2px rgba(0, 0, 0, 0.8),
        0 1px 3px rgba(0, 0, 0, 0.8);

    box-shadow:
        0 0 0 1px rgba(0, 0, 0, 0.2),
        0 4px 12px rgba(0, 0, 0, 0.25),
        inset 0 1px 1px rgba(255, 255, 255, 0.25);

    cursor: pointer;
    transition: all 0.15s ease;
}

.hint-button:hover {
    background: rgba(255, 255, 255, 0.28);
    transform: translateY(-2px);

    box-shadow:
        0 0 0 1px rgba(0, 0, 0, 0.3),
        0 8px 20px rgba(0, 0, 0, 0.3),
        inset 0 1px 1px rgba(255, 255, 255, 0.3);
}

.hint-button:active {
    transform: translateY(1px);

    box-shadow:
        0 0 0 1px rgba(0, 0, 0, 0.2),
        0 2px 6px rgba(0, 0, 0, 0.25),
        inset 0 2px 4px rgba(0, 0, 0, 0.15);
}

.hint-button:disabled {
    background: rgba(100, 100, 100, 0.25);
    color: rgba(255, 255, 255, 0.55);
    border-color: rgba(0, 0, 0, 0.2);

    cursor: not-allowed;
    transform: none;
    box-shadow: none;
}

.play-again-button {
    width: 100px;
    height: 40px;

    background: rgba(255, 255, 255, 0.18);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);

    border: 1px solid rgba(0, 0, 0, 0.6);
    border-radius: 10px;

    color: #ffffff;
    font-size: 14px;
    font-weight: 700;

    text-shadow:
        0 0 2px rgba(0, 0, 0, 0.8),
        0 1px 3px rgba(0, 0, 0, 0.8);

    box-shadow:
        0 0 0 1px rgba(0, 0, 0, 0.2),
        0 4px 12px rgba(0, 0, 0, 0.25),
        inset 0 1px 1px rgba(255, 255, 255, 0.25);

    cursor: pointer;
    transition: all 0.15s ease;
}

.play-again-button:hover {
    background: rgba(255, 255, 255, 0.28);
    transform: translateY(-2px);

    box-shadow:
        0 0 0 1px rgba(0, 0, 0, 0.3),
        0 8px 20px rgba(0, 0, 0, 0.3),
        inset 0 1px 1px rgba(255, 255, 255, 0.3);
}

.play-again-button:active {
    transform: translateY(1px);

    box-shadow:
        0 0 0 1px rgba(0, 0, 0, 0.2),
        0 2px 6px rgba(0, 0, 0, 0.25),
        inset 0 2px 4px rgba(0, 0, 0, 0.15);
}

.play-again-button:disabled {
    background: rgba(100, 100, 100, 0.25);
    color: rgba(255, 255, 255, 0.55);
    border-color: rgba(0, 0, 0, 0.2);

    cursor: not-allowed;
    transform: none;
    box-shadow: none;
}