/* Кнопка звука демо (features/sound.js): левый нижний угол, ниже мобильного меню (z-index 99) и модалок */
.sound-toggle {
    position: fixed;
    left: 16px;
    bottom: calc(16px + env(safe-area-inset-bottom, 0px));
    z-index: 90;
    width: 42px;
    height: 42px;
    display: grid;
    place-items: center;
    border-radius: 50%;
    border: 1px solid var(--border-color);
    background: rgba(20, 22, 24, 0.85);
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
    box-shadow: 0 4px 16px rgba(0, 0, 0, 0.4);
    font-size: 1.05rem;
    line-height: 1;
    cursor: pointer;
    transition: border-color 0.2s ease, box-shadow 0.2s ease, transform 0.2s ease;
}

.sound-toggle:hover {
    border-color: var(--gold-primary);
    transform: translateY(-1px);
}

.sound-toggle[aria-pressed="true"] {
    border-color: var(--gold-primary);
    box-shadow: 0 0 0 3px var(--gold-glow), 0 4px 16px rgba(0, 0, 0, 0.4);
}

.sound-toggle:focus-visible {
    outline: 2px solid var(--gold-primary);
    outline-offset: 3px;
}