body {
padding: 0;
margin: 0;
}
#container {
height: 100px;
display: flex;
flex-direction: row;
}
#panel {
flex: 1;
overflow-y: auto;
background: red;
}
#map {
flex: 3;
background: blue;
}
<div id="container">
<div id="panel"></div>
<div id="map"></div>
</div>
$(function () {
$('#container').css('height', $(window).height() + 'px')
})