*{text-decoration:none;list-style:none}body{margin:0;background:black}h1,h2,h3,h4,h5,h6,p{margin:0;padding:0;color:#fff;font-family:Roboto}ol,ul{margin:0;padding:0;list-style:none}a{text-decoration:none}img{display:block;max-width:100%;height:auto}button{border:none;background:none;color:#fff}button:hover{cursor:pointer}body{background:black;padding:20px}button{width:150px;height:30px;font-size:1.3rem}.first-exercise-div{height:150px;display:flex;flex-direction:column;align-items:center;margin-bottom:100px}.first-title{margin-bottom:40px}.second-exercise-div{height:500px;display:flex;flex-direction:column;align-items:center;justify-content:space-between;margin-bottom:100px}.div{width:100px;height:100px;border-radius:4px}.div:nth-of-type(1){background:blue}.div:nth-of-type(2){background:red}.div:nth-of-type(3){background:green}.third-exercise{width:550px;height:700px;display:flex;flex-direction:column;align-items:center;justify-content:space-around;outline:1px gray solid;margin:0 auto 100px}#interactive-game{width:500px;height:500px;outline:red 1px solid;position:relative}.target{width:50px;height:50px;background-color:#dc143c;position:absolute;cursor:pointer;transition:.2s}.fourth-exercise{width:auto;height:300px;display:flex;flex-direction:column;align-items:center;justify-content:space-around}#time-input{border:3px solid gray;border-radius:2px;background:none;color:#fff}#time-input::placeholder{color:#fff}#time-input:focus{outline:1px solid red}