纯CSS实现可自定义间距虚线边框-526互联

<!DOCTYPE html>
<html>
    <head>
        <meta charset="utf-8">
        <title></title>
        <style>
            .border-wrapper {
                position: relative;
                margin: 100px auto;
                width: 200px;
                height: 50px;
                background: #ff0000;
                z-index: 9999;
                border-radius: 5px;
            }
            
            .border-top {
                width: calc(100% - 10px);
                left: 5px;
                height: 1px;
                background-image: linear-gradient(to right, #fff 0%, #fff 50%, transparent 50%);
                background-size: 11px 1px;
                background-repeat: repeat-x;
                position: absolute;
            }
            
            .border-left {
                width: 1px;
                left: 0;
                top: 5px;
                height: calc(100% - 10px);
                background-image: linear-gradient(to top, #fff 0%, #fff 50%, transparent 50%);
                background-size: 1px 11px;
                background-repeat: repeat-y;
                position: absolute;
            }
            
            .border-bottom {
                width: calc(100% - 10px);
                left: 5px;
                height: 1px;
                bottom: 0;
                background-image: linear-gradient(to right, #fff 0%, #fff 50%, transparent 50%);
                background-size: 11px 1px;
                background-repeat: repeat-x;
                position: absolute;
            }
            
            .border-right {
                width: 1px;
                right: 0;
                top: 5px;
                height: calc(100% - 10px);
                background-image: linear-gradient(to top, #fff 0%, #fff 50%, transparent 50%);
                background-size: 1px 11px;
                background-repeat: repeat-y;
                position: absolute;
            }
            
            .button-wrapper {
                position: relative;
                width: calc(100% - 2px);
                height: calc(100% - 2px);
                border-radius: 4px;
                background: #ffffff;
                top: 1px;
                left: 1px;
            }
        </style>
    </head>
    <body>
        <div class="border-wrapper">
            <div class="border-top"></div>
            <div class="border-left"></div>
            <div class="border-bottom"></div>
            <div class="border-right"></div>
            <div class="button-wrapper"></div>
        </div>
    </body>
</html>