styles.css

*{
    box-sizing: border-box;
    
}

body{
    display: flex;
}

 #container{
    border: 2px solid black;
    height: 300px;
    margin: auto;
    width: 50%;
    padding: 15px;
    display: inline-block;
    text-align: center;
    background: linear-gradient(to left, #5c6f81, #bdc3c7);
    border-radius: 50px;
    transition: background ease-out;
}

#title{
    margin: auto;
    text-align: center;
    color: black;
    font-family: "Edu NSW ACT Foundation", cursive;
    animation: 3s infinite alternate slidein;

}

#activity-name{
    text-align: center;
    height: 100px;
    color: black;
    margin-top: 50px;
}

#btn{
    margin: auto;
    border-radius: 500px;
    font-size: 30px;
    width: 80px;
    height: 50px;
    text-align: center;
    vertical-align: middle;
    font-family: "Edu NSW ACT Foundation", cursive;
    background-color: lightyellow;
}

#btn:hover{
    background-color: yellow;
}