TmMolStar/src/mol-app/skin/layout/common.scss

.molstar-layout-expanded, .molstar-layout-standard {
    left: 0;
    right: 0;
    top: 0;
    bottom: 0;
}

.molstar-layout-region {
    overflow: hidden;
    background: $default-background;
}

.molstar-layout-static, .molstar-layout-scrollable {
    position: absolute;
}

.molstar-layout-scrollable {
    overflow-y: auto;
}

.molstar-layout-static {
    overflow: hidden;
}

.molstar-layout-main, .molstar-layout-bottom, .molstar-layout-top {
    .molstar-layout-static {
        left: 0;
        right: 0;
        top: 0;
        bottom: 0;
    }
}

.molstar-layout-right {

    .molstar-layout-static {
        left: 0;
        right: 0;
        top: 0;
        height: $row-height + $control-spacing;
    }

    .molstar-layout-scrollable {
        left: 0;
        right: 0;
        top: $row-height + $control-spacing + 1;
        bottom: 0;
     }

}

.molstar-layout-left {
    .molstar-layout-static {
        left: 0;
        right: 0;
        bottom: 0;
        top: 0;
    }
}