style.css

*{
    margin: 0;
    padding: 0;
    font-family:'poppins', sans-serif;
    box-sizing: border-box;
}

body{
    background: #4897f7;
}
body h1{
    text-align: center;
}
.app{
    background-color: #fff;
    margin: 100px auto 0;
    width: 90%;
    max-width: 600px;
    border-radius:30px;
    padding: 30px;
}
.app h1{
    font-size: 25px;
    color: rgb(82, 135, 32);
    font-weight: 600;
    border-bottom: 1px solid #333;
    padding-bottom: 30px;
}
.quiz{
    padding: 20px 0;
}
.quiz h2{
    font-size: 18px;
    color: #333;
    font-weight: 600 ;
}
.btn{
    background: #fff;
    color: #222;
    font-weight: 500;
    width: 100%;
    border: 1px solid #222;
    padding: 10px;
    margin:  10px 0;
    text-align: center;
    border-radius: 7px;
    cursor: pointer;
    transition: all 0.3s;
}

.btn:hover([disabled]){
    background: #4897f7;
    color: #fff;
}

.btn:disabled{
    cursor: no-drop;
}

#next-btn{
    background: #2585f9;
    color: #fff;
    font-weight: 500;
    width: 90px;
    border: 1px solid #333;
    border-radius: 9px;
    padding: 7px;
    margin: 10px auto 0;
    cursor: pointer;
    display: none;
    
}

.correct{
    background: rgb(132, 222, 132);
}

.incorrect{
    background: rgb(234, 18, 18);
}

footer{
    padding: 50px;
    margin: 10% auto 0;
   
}

footer p{
    color: #222;
    text-align: center;
}