//== 页面右上角用户信息
.hd_user_info {
    $avatar-size: 20px;
    @include e(avatar) {
        display: inline-block;
        width: $avatar-size;
        height: $avatar-size;
        border-radius: 50%;
        vertical-align: middle;
        background-position: 50%;
        @include img-retina($image-path-base + "avatar.png", $image-path-base + "avatar@2x.png", $avatar-size, $avatar-size);
    }
}