style.css

/* Fonts and Base Styles */
@import url('https://fonts.googleapis.com/css2?family=Belanosima&family=Jost:wght@700&display=swap');

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

html,
body {
    /* For 1 rem = 10 px */
    font-size: 62.5%;
    background-color: #1abf1a1c;
}

/* Centering Wrapper */
.wrapper {
    display: flex;
    justify-content: center;
    align-items: center;
    height: 100vh;
    width: 100vw;
}

/* Main Game Area */
main {
    width: 75%;
    height: 75%;
    box-shadow: rgba(17, 17, 26, 0.1) 0px 8px 24px, rgba(17, 17, 26, 0.1) 0px 16px 56px, rgba(17, 17, 26, 0.1) 0px 24px 80px;
    border-radius: 1rem;
    overflow: hidden;
    position: relative;
}

/* Header */
header {
    display: flex;
    justify-content: space-evenly;
    align-items: center;
    flex-flow: row wrap;
    flex: 1 1 0;
    background-color: #bf1a1a94;
    font-size: 2rem;
    min-height: 7rem;
}

/* Individual Header Items */
.item {
    padding: 1rem;
    text-align: center;
}

.item h3 {
    display: inline;
    padding: 1rem;
}

.item .box {
    background-color: rgb(255, 255, 255);
    padding: 0.5rem 1.5rem;
    border-radius: 3px;
}

/* Game Area */
#root {
    height: calc(100% - 7rem);
    background-color: rgba(255, 0, 0, 0.229);
    width: 100%;
    overflow: hidden;
    display: flex;
    justify-content: center;
    align-items: center;
    flex-flow: row wrap;
}

/* Bubbles */
.bubble {
    width: 4rem;
    height: 4rem;
    border-radius: 50%;
    background-color: #ffffff;
    display: flex;
    font-size: 1.6rem;
    margin: 0.5rem;
    justify-content: space-evenly;
    align-items: center;
    cursor: pointer;
    transition: background-color 0.3s, color 0.3s;
}

/* Hover and Visited Bubble Styles */
.bubble:hover,
.bubble:visited {
    background-color: #bf1a1a94;
    color: #ffffff;
}

/* Game Over Message */
h1 {
    font-size: 3rem;
    text-align: center;
    padding: 2rem;
    background-color: #bf1a1a94;
    color: #fff;
    border-radius: 0.5rem;
}

/* Media Query */
@media only screen and (max-width: 50em) {
    html, body {
        font-size: 38.5%;
    }
}