<div id="container">
            <div class="sol">Sol</div>
            <div class="sag">Sağ</div>
</div>
      <style>
            #container {
                position: relative;
                width: 100%;
            }
            .sol {
                width: 100px;
                height: 100px;
                background: red;
                display: inline-block;
                
            }
            .sag {
                width: 100px;
                height: 100px;
                background: red;
                display: inline-block;
                ;
            }
        </style>