前端例程20220818：边框跑马霓虹灯效按钮

演示

在这里插入图片描述
原理

按钮使用阴影实现外发光效果；
按钮设置倒影效果；
使用四个块元素以按钮为基础绝对定位到上下左右四边作为边框；
通过给边框元素设置动画，并设置动画时间差以实现边框跑马效果；
代码

DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1, user-scalable=no">
    <title>边框跑马霓虹灯效按钮title>

    <style>
        * {
            padding: 0;
            margin: 0;
            user-select: none;
            box-sizing: border-box;
        }

        html,
        body {
            height: 100vh;
        }
    style>

    <style>
        /* 全局色表 */
        :root {
            --color-bg: #202020;
            --color-btn1: #f556e0;
            --color-btn2: #5182f7;
        }

        body {
            display: flex;
            background: var(--color-bg);
            align-items: center;
            justify-content: center;
        }

        .btn {
            width: 200px;
            height: 50px;
            margin: 20px;
            background: transparent;
            border: none;
            font-size: 24px;
            letter-spacing: 4px;
            transition: 0.3s;
            /* 倒影。通过遮罩透明度变化实现近处明亮远处黯淡的效果 */
            -webkit-box-reflect: below 1px linear-gradient(to bottom, transparent, rgba(0, 0, 0, 0.3));
        }

        .btn:nth-child(1) {
            color: var(--color-btn1);
        }

        .btn:nth-child(2) {
            color: var(--color-btn2);
        }

        .btn:focus {
            outline: none;
        }
    style>

    
    <style>
        .btn:hover {
            color: var(--color-bg);
        }

        .btn:nth-child(1):hover {
            background: var(--color-btn1);
            /* 多层阴影增加发光效果的层次感 */
            box-shadow: 0 0 10px var(--color-btn1),
                0 0 25px var(--color-btn1),
                0 0 50px var(--color-btn1),
                0 0 100px var(--color-btn1);
        }

        .btn:nth-child(2):hover {
            background: var(--color-btn2);
            box-shadow: 0 0 10px var(--color-btn2),
                0 0 25px var(--color-btn2),
                0 0 50px var(--color-btn2),
                0 0 100px var(--color-btn2);
        }
    style>

    
    <style>
        .btn {
            position: relative;
            overflow: hidden;
        }

        .btn span {
            position: absolute;
            display: block;
        }

        /* 下面是各条边框位置与动画设置，通过位置和动画时间差实现跑马效果 */

        .btn span:nth-child(1) {
            top: 0;
            left: -100%;
            width: 100%;
            height: 2px;
            animation: animate1 1s linear infinite;
            animation-delay: 0s;
        }

        @keyframes animate1 {
            0% {
                left: -100%;
            }

            50%,
            100% {
                left: 100%;
            }
        }

        .btn span:nth-child(2) {
            top: -100%;
            right: 0;
            width: 2px;
            height: 100%;
            animation: animate2 1s linear infinite;
            animation-delay: 0.25s;
        }

        @keyframes animate2 {
            0% {
                top: -100%;
            }

            50%,
            100% {
                top: 100%;
            }
        }

        .btn span:nth-child(3) {
            bottom: 0;
            right: -100%;
            width: 100%;
            height: 2px;
            animation: animate3 1s linear infinite;
            animation-delay: 0.5s;
        }

        @keyframes animate3 {
            0% {
                right: -100%;
            }

            50%,
            100% {
                right: 100%;
            }
        }

        .btn span:nth-child(4) {
            bottom: -100%;
            left: 0;
            width: 2px;
            height: 100%;
            animation: animate4 1s linear infinite;
            animation-delay: 0.75s;
        }

        @keyframes animate4 {
            0% {
                bottom: -100%;
            }

            50%,
            100% {
                bottom: 100%;
            }
        }

        /* 下面是各条边框颜色设置 */

        .btn:nth-child(1) span:nth-child(1) {
            background: linear-gradient(to right, transparent, var(--color-btn1));
        }

        .btn:nth-child(2) span:nth-child(1) {
            background: linear-gradient(to right, transparent, var(--color-btn2));
        }

        .btn:nth-child(1) span:nth-child(2) {
            background: linear-gradient(to bottom, transparent, var(--color-btn1));
        }

        .btn:nth-child(2) span:nth-child(2) {
            background: linear-gradient(to bottom, transparent, var(--color-btn2));
        }

        .btn:nth-child(1) span:nth-child(3) {
            background: linear-gradient(to left, transparent, var(--color-btn1));
        }

        .btn:nth-child(2) span:nth-child(3) {
            background: linear-gradient(to left, transparent, var(--color-btn2));
        }

        .btn:nth-child(1) span:nth-child(4) {
            background: linear-gradient(to top, transparent, var(--color-btn1));
        }

        .btn:nth-child(2) span:nth-child(4) {
            background: linear-gradient(to top, transparent, var(--color-btn2));
        }
    style>
head>

<body>
    
    <button class="btn">
        <span>span>
        <span>span>
        <span>span>
        <span>span>
        BUTTON
    button>
    <button class="btn">
        <span>span>
        <span>span>
        <span>span>
        <span>span>
        BUTTON
    button>
body>

html>
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前端例程20220818：边框跑马霓虹灯效按钮

演示

原理

代码

更多例程
