@keyframes gradientBG {
    0% {
        background-position: 0% 50%;
    }

    50% {
        background-position: 100% 50%;
    }

    100% {
        background-position: 0% 50%;
    }
}

/* 底部功能区 */
#bottom-controls {
    position: absolute;
    bottom: 40px;
    left: 0;
    width: 100%;
    z-index: 20;
    display: flex;
    justify-content: space-between;
    padding: 0 40px;
    pointer-events: none;
    /* 确保按钮区域外不捕获事件 */
}

.control-btn {
    width: 60px;
    height: 60px;
    border-radius: 50%;
    background-color: #0000004D;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    pointer-events: auto;
    /* 允许按钮接收事件 */
    box-shadow: 0 4px 10px rgba(0, 0, 0, 0.3);
    border: none;
    transition: background 0.3s ease;
}

.btn-icon {
    width: 28px;
    height: 28px;
    object-fit: contain;
}

/* 响应式调整 */
@media (max-width: 768px) {
    #bottom-controls {
        bottom: 30px;
        padding: 0 30px;
    }

    .control-btn {
        width: 50px;
        height: 50px;
    }

    .btn-icon {
        width: 24px;
        height: 24px;
    }
}