body {
     height: 100vh;
     display: flex;
     align-items: center;
     justify-content: center;
 }

 div {
     width: 100px;
     height: 100px;
     display: flex;
     align-items: center;
     justify-content: center;
     margin: 0 10px;
 }

 span {
     width: 50px;
     height: 50px;
 }

 #one,
 #two {
     background-color: beige;
 }

 #box {
     background-color: chartreuse;
 }