1px

less中：

.border-scale(@color, @border-radius: 0px,    @border-width: 1px 1px 1px 1px){    &:after{        content: " ";        position: absolute;        top: 0;        left: 0;        width: 200%;        height: 200%;        border: 1px solid @color;        border-width: @border-width;        border-radius: 2 * @border-radius;        transform-origin: 0% 0%;        -webkit-transform-origin: 0% 0%;        -webkit-transform: scale(0.5, 0.5);        transform: scale(0.5, 0.5);        pointer-events: none;        -webkit-box-sizing: border-box;        box-sizing: border-box;    }}

css中：

.border-scale(#4A4C5B, 1px, 1px);