vant/packages/zanui-css/src/uploader.css

@component-namespace zan {
    @b uploader {
        position: relative;
        display: inline-block;

        @e input {
            position: absolute;
            top: 0;
            right: 0;
            bottom: 0;
            left: 0;
            display: block;
            width: 100%;
            height: 100%;
            opacity: 0;
            cursor:pointer;
        }

        input[type="file" i]::-webkit-file-upload-button {
            cursor:pointer;
        }
    }
}