TestPage.css

body {
    font-family: 'Segoe UI';
    font-size: 14px;
}

.LineDiv:after {
    content: " ";
    display: block;
    clear: both;
}

.DraggableHandle {
    display: block;
    width: 10px;
    height: 10px;
    position: absolute;
    cursor: nwse-resize;
    border-radius: 5px;
}

.TabPage table {
    margin: 10px;
    border-left: 1px solid gray;
    border-top: 1px solid gray;
    border-spacing: 0px;
    border-collapse: separate;
}

.TabPage th {
    text-align: left;
    padding: 10px;
    border-right: 1px solid gray;
    border-bottom: 1px solid gray;
}

.TabPage td {
    text-align: left;
    border-right: 1px solid gray;
    border-bottom: 1px solid gray;
}

    .TabPage td:after {
        content: " ";
        display: block;
        clear: both;
    }

.TabButtonContainer:after {
    content: " ";
    display: block;
    clear: both;
}


.TabButton {
    box-shadow: inset 0px 1px 0px 0px #54A3F7;
    background: linear-gradient(to bottom, #007DC1 5%, #0061A7 100%);
    background-color: #007DC1;
    border-radius: 3px;
    border: 1px solid #124D77;
    display: inline-block;
    cursor: pointer;
    color: #FFFFFF;
    padding: 6px 24px;
    text-align: center;
    text-decoration: none;
    text-shadow: 0px 1px 0px #154682;
    margin: 4px;
    width: 6em;
    display: block;
    float: left;
    cursor: pointer;
}

    .TabButton:active {
        background: linear-gradient(to bottom, #0061A7 5%, #007DC1 100%);
        background-color: #0061A7;
    }

.Selected.TabButton {
    font-weight: 700;
}

    .Selected.TabButton:before {
        content: "<";
    }

    .Selected.TabButton:after {
        content: ">";
    }

.TabPageContainer {
    display: block;
    position: relative;
}

.TabPage {
    display: block;
    position: absolute;
    left: 0;
    top: 0;
    right: 0;
    visibility: hidden;
}

.Selected.TabPage {
    visibility: visible;
    border: 1px solid red;
}