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

body{
    background: #001e4d;
}

.app{
    background: white;
    width: 90%;
    max-width: 600px;
    margin: 100px auto 0;
    border-radius: 10px;
    padding: 30px;
}

.app h1{
    font-size: 25px;
    color: #001e4d;
    font-weight: 600;
    border-bottom: 1px solid #333;
    padding-bottom: 30px;
}

.quiz{
    padding: 20px 0;
}

.quiz h2{
    font-size: 18px;
    color: #001e4d;
    font-weight: 600;
}

.btn{
    background: white;
    color: #222;
    font-weight: 500;
    width: 100%;
    border: 1px solid #222;
    padding: 10px;
    margin: 10px 0;
    text-align: left;
    border-radius: 4px;
    cursor: pointer;
    transition: all 0.3s;
}

.btn:hover:not([disabled]){
    background: #222;
    color: white;
}

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

#next-btn{
    background: #001e4d;
    color: white;
    font-weight: 500;
    width: 150px;
    border: 0;
    padding: 10px;
    margin: 20px auto 0;
    border-radius: 4px;
    cursor: pointer;
    display: 'block';
}

.correct{
    background: #9aeabc;
}

.incorrect{
    background: #ff9393;
}


@media screen and (max-width: 480px) {
    body {
        padding: 10px;
    }

    .app {
        width: 95%;
        padding: 15px;
        margin: auto;
    }

    h1 {
        font-size: 20px;
        text-align: center;
    }

    .quiz {
        font-size: 14px;
        line-height: 1.4;
    }

    .btn {
        width: 100%;
        font-size: 14px;
        padding: 10px;
        margin-top: 8px;
    }

    #next-btn {
        width: 100%;
        font-size: 14px;
        margin-top: 10px;
    }
}


@media screen and (min-width: 481px) and (max-width: 768px) {
    .app {
        width: 80%;
        padding: 20px;
    }

    h1 {
        font-size: 24px;
    }

    .btn, #next-btn {
        font-size: 16px;
        padding: 12px;
    }
}


@media screen and (min-width: 769px) and (max-width: 1024px) {
    .app {
        width: 70%;
    }
}