.floating-action {
    position: fixed;
    right: 40px;
    bottom: 150px;
    z-index: 9999;
    width: 70px;
    height: 70px;
    border-radius: 50%;
    background: #fff;
    box-shadow: 0 8px 20px rgba(0,0,0,0.18);
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 6px; /* 关键：内边距，防止图片边缘被裁掉 */
    box-sizing: border-box;
    overflow: hidden;
}


    /* img 使用 contain 并允许自适应 */
    .floating-action img {
        width: 100%;
        height: 100%;
        object-fit: contain;
        display: block;
    }

    /* 悬停与聚焦效果 */
    .floating-action:hover,
    .floating-action:focus-within {
        transform: translateY(-4px);
        box-shadow: 0 14px 32px rgba(0,0,0,0.22);
    }

    /* 点击时的按压效果 */
    .floating-action:active {
        transform: translateY(-1px) scale(.99);
    }

/* 小屏隐藏（如果你想一直显示，可删掉下面 media rule） */
@media (max-width: 600px) {
    .floating-action {
        display: none;
    }
}