MediaWiki:2colmainpage.css

/* this CSS governs the responsive 2 column main page layout */
.fpmaybecols {
    overflow: hidden;
    margin: -5px 0;
}

.fpmaybecols + .fpmaybecols {
    margin: 0 0 -5px;
}

.fpbox .heading .smalllink {
    color: #e0e0e0;
    font-size: 75%;
    font-weight: bold;
}

.fpbox hr {
    border: none;
    border-bottom: 2px solid #505050;
}

@media (min-width: 990px) {
    .fpmain {
        padding-right: 520px;
        width: auto;
    }

    #fpbottomsection,
    #fptopsection {
        float: left;
        width: 100%;
    }

    #fpflexsection {
        float: right;
        width: 520px;
        margin-right: -520px;
    }

    #fpbottomsection {
        margin-top: -5px;
    }
}