style.css

:root {
    background-color: #ecf5ff;
    font-size: 62.5%;
}

body {
    background-image: url(./images/bg.jpg);
}

*{
    box-sizing: border-box;
    font-family: Arial, Arial, Helvetica, sans-serif;
    margin: 0;
    padding: 0;
    color: #333;
}

/* Utilities */

h1, h2, h3, h4 {
    margin-bottom: 1rem;
} 

h1 {
    font-size: 5.4rem;
    color: #56a5eb;
    margin-bottom: 5rem;
}

h1 > span{
    font-size: 2.4rem;
    font-weight: 500;
}

h2 {
    color:  rgb(240, 76, 0);
    font-size: 4.2rem;
    margin-bottom: 4rem;
    font-weight: 700;
    text-align: center;
}

h3 {
    font-size: 2.8rem;
    font-weight: 500;
}

p {
    color: rgb(240, 76, 0);
}

#question {
    width: auto;
    background-color: rgb(83, 82, 80);
}

#title {
    color: rgb(240, 76, 0);
    width: auto;
    border: 0.1rem solid rgba(240, 76, 0, 0.25);
}

.container {
    width: 100vw;
    height: 100vh;
    display: flex;
    justify-content: center;
    align-items: center;
    max-width: 80 rem;
    margin: 0 auto;
    padding: 2rem;
}

.container > * {
    width: 100%;
}

.flex-column {
    display: flex;
    flex-direction: column;
}

.flex-center {
    justify-content: center;
    align-items: center;
}

.justify-center {
    justify-content: center;
}

.text-center {
    text-align: center;
}

.hidden {
    display: none;
}

/* Button */

.btn {
    font-size: 1.8rem;
    padding: 1rem 0;
    width: 20rem;
    text-align: center;
    border: 0.1rem solid #56a5eb;
    margin-bottom: 1rem;
    text-decoration: none;
    color: #56a5eb;
    background-color: white;
}

.btn:hover {
    cursor: pointer;
    box-shadow: 0 0.4rem 1.4rem 0 rgba(86, 185, 235, 0.5);
    transform: translateY(-0.1rem);
    transition: transform 150ms;
}

.btn[disabled]:hover {
    cursor: not-allowed;
    box-shadow: none;
    transform: none;
}

/* game */

.choice-container {
    display: flex;
    margin-bottom: 0.5rem;
    width: 100%;
    font-size: 1.8rem;
    border: 0.1rem solid rgba(86, 165, 235, 0.25);
    background-color: rgb(83, 82, 80);
}

.choice-container:hover {
    cursor: pointer;
    box-shadow: 0 0.4rem 1.4rem 0 rgba(86, 185, 235, 0.5);
    transform: translateY(-0.1rem);
    transition: transform 150ms;
}

.choice-prefix {
    padding: 1.5rem 2.5rem;
    background-color: #56a5eb;
    color: white;
}

.choice-text{
    padding: 1.5rem;
    width: 100%;
}

.correct {
    background-color: #28a745;
}

.incorrect {
    background-color: #dc3545;
}

/* HUD */

#hud {
    display: flex;
    justify-content: space-between;
}

.hud-prefix {
    text-align: center;
    font-size: 2rem;
}

.hud-main-text {
    text-align: center;
}