CSS conflict on Media Library

Hi there,

In the most recent update, this particular CSS code in wpmu-lib/css/wpmu-ui.3.min.css is causing a conflict with the media library CSS. The selection check marks are no longer appearing correctly.

I would suggest to wrap the CSS code in WPMU-specific wrapper class so that it doesn’t conflict with WordPress’ UI.

#wpwrap .button-link, .wpmui-form .button-link, .wpmui-popup .button-link {
    display: inline-block;
    text-decoration: underline;
    font-size: 13px;
    line-height: 26px;
    height: 28px;
    padding: 0 10px 1px;
    cursor: pointer;
    white-space: nowrap;
    color: #0074A2;
    background: transparent;
    border: 0;
    -webkit-box-sizing: border-box;
    -moz-box-sizing: border-box;
    box-sizing: border-box;
    -webkit-box-shadow: 0 0 0 transparent;
    -moz-box-shadow: 0 0 0 transparent;
    box-shadow: 0 0 0 transparent;
    -webkit-transition-property: border,background,color;
    transition-property: border,background,color;
    -webkit-transition-duration: .05s;
    transition-duration: .05s;
    -webkit-transition-timing-function: ease-in-out;
    transition-timing-function: ease-in-out;
}