hidden.css

/*
 * http://adaptivethemes.com/using-css-clip-as-an-accessible-method-of-hiding-content
 * http://snook.ca/archives/html_and_css/hiding-content-for-accessibility
 * http://developer.yahoo.com/blogs/ydn/clip-hidden-content-better-accessibility-53456.html
 * https://github.com/h5bp/html5-boilerplate/issues/194
 */

/* Hide from both screenreaders and browsers */
.hidden {
    display: none !important;
    visibility: hidden;
}

/* Hide only visually, but have it available for screenreaders */
.hidden-visually {
    border: 0;
    clip: rect(0 0 0 0);
    height: 1px;
    margin: -1px;
    overflow: hidden;
    padding: 0;
    position: absolute;
    width: 1px;
}