如何用SCSS实现渐变按钮Hover时360度无限旋转效果

我主页里有个按钮，想要实现鼠标悬停时按钮的渐变边框360度无限旋转效果，目前自己的SCSS水平搞不定，希望能让主页更出彩。以下是我的JSX和SCSS代码：

我的JSX代码： #

<section className='section-cover'>
        <div className='cover-title'>
          <h1>Blah Blah, Blah Blah </h1>
          <h2>You never have to do it yourself again, Blah Blah Blah Blah and let someone do the work for you.</h2>
          <button className='try-out'>Try Us Out</button>
        </div>
        <img className='cuttingBlah' src={cuttingBlah}/>
</section>

我的SCSS代码： #

.section-cover {
    margin-top: 60px;
    display: flex;
    flex-direction: row;
    justify-content: flex-end;
    align-items: center;
    background-color: transparent;
    padding: 50px 100px;
    position: relative;
    z-index: 1;
    ::before, ::after {
        content: '';
        position: absolute;
        inset: 0;
        background: linear-gradient(
            0deg,
            var(--color-2),
            var(--color-3),
            var(--color-4),
            var(--color-5),
            var(--color-6),
        );
        z-index: -1;
    }
    ::before {
        filter: blur(0.5rem);
    }
    .cover-title {
        z-index: 2;
        h1, h2 {
            color: black;
            margin: 0px;
        }
        h1 {
            font-size: 55px;
            margin-bottom: 30px;
        }
        .try-out {
            box-sizing: content-box;
            font-weight: bold;
            font-size: large;
            padding: 1rem 2rem;
            cursor: pointer;
            position: relative;
            border: 10px solid transparent;
            background: linear-gradient(white, white) padding-box,
                        linear-gradient( to right, #5ddcff, #3c67e3 43%, #4e00c2) border-box;
            border-radius: 20px;
            margin-top: 20px;
            overflow: hidden; 
            transition: transform 0.5s ease; 
        }
    }
    .cuttingBlah {
        border-radius: 10px;
        width: 520px;
        z-index: 2;
    }
}

解决方案 #

要实现渐变边框的无限旋转，需要借助CSS动画和伪元素来实现，直接旋转border渐变的方式难以操作。修改后的.try-out部分SCSS代码如下：

.try-out {
    box-sizing: content-box;
    font-weight: bold;
    font-size: large;
    padding: 1rem 2rem;
    cursor: pointer;
    position: relative;
    border: 10px solid transparent;
    background: linear-gradient(white, white) padding-box;
    border-radius: 20px;
    margin-top: 20px;
    overflow: hidden;
    transition: transform 0.5s ease;

    // 伪元素实现旋转渐变背景
    &::before {
        content: '';
        position: absolute;
        top: -50%;
        left: -50%;
        width: 200%;
        height: 200%;
        background: linear-gradient(
            to right, 
            #5ddcff, 
            #3c67e3 43%, 
            #4e00c2,
            #5ddcff
        );
        z-index: -1;
        opacity: 0;
        transition: opacity 0.3s ease;
        animation: rotate 3s linear infinite;
    }

    // 悬停时显示渐变旋转效果
    &:hover::before {
        opacity: 1;
    }

    // 裁剪出按钮内部白色区域，模拟边框效果
    &::after {
        content: '';
        position: absolute;
        inset: 10px; // 与按钮border宽度保持一致
        background: white;
        border-radius: 10px; // 原border-radius减去border宽度
        z-index: -1;
    }
}

// 定义360度旋转动画
@keyframes rotate {
    from {
        transform: rotate(0deg);
    }
    to {
        transform: rotate(360deg);
    }
}

关键说明 #

• 用::before伪元素创建一个超出按钮范围的渐变背景，宽高设为200%避免旋转时露出空白区域
• 初始状态下伪元素透明度为0，hover时切换为1，配合动画实现渐变旋转的显隐过渡
• ::after伪元素填充白色并裁剪出内部区域，保证按钮内容区的白色背景不受渐变影响
• 动画时长可以通过调整3s参数来控制旋转速度

内容的提问来源于stack exchange，提问作者Hatter7474