.box-container{display:flex;flex-direction:row}.box{width:50px;height:50px}.first.box{background-color:#f05}.second.box{background-color:rgba(255,0,85,.75)}.third.box{background-color:rgba(255,0,85,.5)}.fourth.box{background-color:rgba(255,0,85,.25)}em{background-color:#ffd500}