* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body{
    background: whitesmoke;
}

.app{
    background: #fff;
    width: 90%;
    max-width: 600px;
    margin: 30px auto;
    border-radius: 10px;
    padding: 0px 30px;
    border: 1px solid #bcbcbc;
}

.app h1{
    font-size: 2.2em;
    color: var(--text-darker-blue);    
    font-weight: 600;
    padding-top: 20px;
    padding-bottom: 10px;
    /*border-bottom: 1px solid #333;
    padding-bottom: 30px;*/
}

.app h4{
    font-size: 1.2em;
    text-align: center;
    color: var(--text-darker-blue);    
    font-weight: 400;
    border-bottom: 1px solid #333;
    padding-top: 0px;
    padding-bottom: 20px;
}

.quiz{
    padding: 0 0 10px 0;
}

.quiz h2{
    font-size: 1.2em;
    color: var(--text-color);
    font-weight: 600;
}
.btn{
    background: #fff;
    color: #222;
    font-size: 0.9em;
    font-weight: 500;
    width: 100%;
    border:1px solid #222;
    padding: 10px;
    margin: 7px 0;
    text-align: left;
    border-radius: 4px;
    cursor: pointer;
    transition: all 0.3s;
}
.btn:hover:not([disabled]){
    background: #222;
    color: #fff;  
}
.btn:disabled{
    cursor: no-drop;
}
#next-btn{
    font-size: 0.9em;
    background: rgb(40, 40, 40);
    color: #fff;
    font-weight: 500;
    width: 150px;
    border: 0;
    padding: 10px;
    margin: 20px auto 0;
    border-radius: 4px;
    cursor: pointer;
    display: none;
}
.correct{
    background: rgb(36, 134, 36);
    color: #fff;
}
.incorrect{
    background: #960000;
    color: #fff;
}


@media (max-width: 550px) {
	.app h1{
        font-size: 1.6em;  
    }
    .app h4{
        font-size: 1em;
    }
    .quiz h2{
        font-size: 0.9em;
        color: var(--text-color);
        font-weight: 600;
    }
    .btn{
        font-size: 0.8em;
    }
}