body { -webkit-box-sizing: border-box; /* Safari/Chrome, other WebKit */ -moz-box-sizing: border-box; /* Firefox, other Gecko */ box-sizing: border-box; /* Opera/IE 8+ */ height:100% } p{ margin: 0px; } canvas { position: absolute; } #toolbar { display: flex; flex-flow: column; height: 100%; position: absolute; padding: 0px 20px 0px 20px; width: 500px; height: 100vh; background-color: rgb(189, 189, 189); } #custom { display: flex; flex-flow: column; height: 100%; /* position: absolute; */ padding: 0px 20px 0px 20px; /* width: 500px; */ /* height: 100vh; */ background-color: rgb(189, 189, 189); } .controls{ display: block; }