It is necessary that two divs have the same height + under the screen.
As now, (blocks of the same height +, not under the screen-)
<style> .container { bottom: 0; left: 0; margin: 0 auto; min-width: 700px; max-width: 900px; padding: 0 20px; position: absolute; right: 0; top: 0; display: table;} .containerLeft { background-color: #000; #padding: 20px; width: 220px; position: absolute; min-height: 100%; #max-height: 100%; margin-top: 0px; table-layout: fixed; #padding-top: 20px; padding-right: 20px; padding-bottom: 0; padding-left: 20px;} .containerRight { margin-left: 260px; background: #fff; border-right: 1px solid rgba(0, 0, 0, 0.25); #box-sizing: border-box; #padding: 30px; padding-top: 25px; padding-right: 30px; padding-bottom: 30px; padding-left: 30px;} </style> <div class="container"> <div class="containerLeft">БЛОК</div> <div class="containerRight">БЛОК2</div> </div> Without javaScript, table.