style.css

@import url('https://fonts.googleapis.com/css2?family=Bricolage+Grotesque:opsz,wght@10..48,200;10..48,300;10..48,400;10..48,500;10..48,600;10..48,700;10..48,800&family=Montserrat:ital,wght@0,100;0,200;0,300;0,400;0,500;0,600;0,700;0,800;0,900;1,100;1,200;1,300;1,400;1,500;1,600;1,700;1,800;1,900&family=Poppins:ital,wght@0,100;0,200;0,300;0,400;0,500;0,600;0,700;0,800;0,900;1,100;1,200;1,300;1,400;1,500;1,600;1,700;1,800;1,900&family=Roboto:ital,wght@0,100;0,300;0,400;0,500;0,700;0,900;1,100;1,300;1,400;1,500;1,700;1,900&display=swap');

* {
    margin: 0;
    padding: 0;
    font-family: 'Bricolage Grotesque', sans-serif;
    font-family: 'Montserrat', sans-serif;
    font-family: 'Poppins', sans-serif;
    font-family: 'Roboto', sans-serif;
    box-sizing: border-box;
}

body {
    background: rgb(3, 0, 50);
    background: linear-gradient(90deg, rgba(3, 0, 50, 1) 0%, rgba(25, 9, 0, 1) 34%, rgba(93, 35, 16, 1) 61%, rgba(106, 5, 37, 1) 100%);
}

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

.app h1 {
    font-size: 40px;
    color: #19000a;
    font-weight: 600;
    border-bottom: 1px solid #333;
    padding-bottom: 30px;
    text-align: center;
}

.quiz {
    padding: 20px 0;
}

.quiz h2 {
    font-size: 20px;
    padding-bottom: 10px;
    color: #19000a;
    font-weight: 600;
}

.btn {
    background: #fff;
    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: rgb(50, 2, 0);
    background: linear-gradient(90deg, rgba(50, 2, 0, 1) 0%, rgba(25, 0, 10, 1) 34%, rgba(5, 64, 57, 1) 61%, rgba(5, 54, 106, 1) 100%);
    color: #fff;
    font-weight: 600;
}

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

#next-btn {
    background: rgb(3, 0, 50);
    background: linear-gradient(90deg, rgba(3, 0, 50, 1) 0%, rgba(25, 9, 0, 1) 34%, rgba(93, 35, 16, 1) 61%, rgba(106, 5, 37, 1) 100%);
    color: #fff;
    font-weight: 500;
    width: 150px;
    border: 0;
    padding: 10px;
    margin: 20px auto 0;
    border-radius: 4px;
    cursor: pointer;
    display: none;
}

#next-btn:hover {
    background: rgb(50, 2, 0);
    background: linear-gradient(90deg, rgba(50, 2, 0, 1) 0%, rgba(25, 0, 10, 1) 34%, rgba(5, 64, 57, 1) 61%, rgba(5, 54, 106, 1) 100%);
}

.correct {
    background: #9aeabc;
}

.incorrect {
    background: #ff9393;
}