style.css

@import url('https://fonts.googleapis.com/css2?family=Press+Start+2P&display=swap');

* {
    box-sizing: border-box;
}

body {
    font-family: 'Press Start 2P', cursive;
    height: 100vh;
    overflow: hidden;
    margin: 0;
    text-align: center;
    background-color: #5C8984;
    color: whitesmoke;
}

a {
    color: whitesmoke;
}

h1 {
    line-height: 1.4;
}

.btn {
    display: block;
    padding: 1em 1em;
    background: transparent;
    outline: none;
    border: 0;
    color: whitesmoke;
    font-family: inherit;
    font-size: 15px;
    font-weight: bold;
    z-index: 1;
    margin-top: 2rem;
    cursor: pointer;
}

.cube {
    position: relative;
    -webkit-transition: all 0.5s;
    transition: all 0.5s;
}

.cube .bg-top {
    position: absolute;
    height: 10px;
    background: whitesmoke;
    bottom: 100%;
    left: 5px;
    right: -5px;
    -webkit-transform: skew(-45deg, 0);
    -ms-transform: skew(-45deg, 0);
    transform: skew(-45deg, 0);
    margin: 0;
    -webkit-transition: all 0.4s;
    transition: all 0.4s;
}

.cube .bg-top .bg-inner {
    bottom: 0;
}

.cube .bg {
    position: absolute;
    left: 0;
    bottom: 0;
    top: 0;
    right: 0;
    background: whitesmoke;
    -webkit-transition: all 0.4s;
    transition: all 0.4s;
}

.cube .bg-right {
    position: absolute;
    background: whitesmoke;
    top: -5px;
    z-index: 0;
    bottom: 5px;
    width: 10px;
    left: 100%;
    -webkit-transform: skew(0, -45deg);
    -ms-transform: skew(0, -45deg);
    transform: skew(0, -45deg);
    -webkit-transition: all 0.4s;
    transition: all 0.4s;
}

.cube .bg-right .bg-inner {
    left: 0;
}

.cube .bg-inner {
    background: #5C8984;
    position: absolute;
    left: 2px;
    right: 2px;
    top: 2px;
    bottom: 2px;
}

.cube .text {
    position: relative;
    -webkit-transition: all 0.4s;
    transition: all 0.4s;
}

.cube:hover .bg-inner {
    background: whitesmoke;
    -webkit-transition: all 0.4s;
    transition: all 0.4s;
}

.cube:hover .text {
    color: #5C8984;
    -webkit-transition: all 0.4s;
    transition: all 0.4s;
}

.cube:hover .bg-right,
.cube:hover .bg,
.cube:hover .bg-top {
    background: #5C8984;
}

.cube:active {
    z-index: 9999;
    -webkit-animation: bounce .1s linear;
    animation: bounce .1s linear;
}

@-webkit-keyframes bounce {
    50% {
        -webkit-transform: scale(0.9);
        transform: scale(0.9);
    }
}

@keyframes bounce {
    50% {
        -webkit-transform: scale(0.9);
        transform: scale(0.9);
    }
}

.btn:focus {
    outline: 0;
}

.by {
    position: absolute;
    bottom: 50px;
}

.screen {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    height: 100vh;
    width: 100vw;
    position: relative;
    transition: margin 0.3s ease-in-out;
}

.screen.up {
    margin-top: -100vh;
}

.insect-list {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    list-style: none;
    padding: 0;
}

.insect-list li {
    margin: 10px;
}

.choose-insect {
    background-color: transparent;
    border: 2px solid whitesmoke;
    color: whitesmoke;
    cursor: pointer;
    font-family: inherit;
    width: 180px;
    height: 180px;
    border-radius: 2px;
}

.choose-insect img {
    width: 100px;
    height: 100px;
    object-fit: contain;
}

.choose-insect:hover {
    background-color: whitesmoke;
    color: #5C8984;
}

.choose-insect:active {
    background-color: rgba(245, 245, 245, 0.7);
}

.emoji {
    font-size: 1.5rem;
}

.time,
.score {
    position: absolute;
    top: 20px;
    letter-spacing: 3px;
}

.time {
    left: 20px;
}

.score {
    right: 20px;
}

.message {
    background-color: #1d2c2bd0;
    font-size: 1.2rem;
    letter-spacing: 2px;
    width: 100%;
    padding: 1.2rem;
    z-index: 100;
    text-align: center;
    opacity: 0;
    position: absolute;
    top: 0;
    left: 50%;
    transform: translate(-50%, -150%);
    transition: transform 0.4s ease-in-out;
}

.message.visible {
    opacity: 1;
    transform: translate(-50%, 150%);
}

.continue-game {
    background-color: #1d2c2bd0;
    font-size: 1.2rem;
    letter-spacing: 2px;
    width: 100%;
    padding: 1.2rem;
    z-index: 100;
    text-align: center;
    opacity: 0;
    position: absolute;
    top: 0;
    left: 50%;
    transform: translate(-50%, -150%);
    transition: transform 0.4s ease-in-out;
}

.continue-game.visible {
    opacity: 1;
    transform: translate(-50%, 150%);
}

.btn-select {
    padding: 1em 1em;
    background: transparent;
    outline: none;
    border: solid 1px whitesmoke;
    text-align: center;
    color: whitesmoke;
    font-family: inherit;
    font-size: 14px;
    cursor: pointer;
}

.btn-select:hover {
    background: whitesmoke;
    border: solid 1px whitesmoke;
    color: #5C8984
}

.insect {
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    width: 80px;
    height: 80px;
    position: absolute;
    transform: translate(-50%, -50%) scale(1);
    transition: transform 0.3s ease-in-out;
}

.insect.caught {
    transform: translate(-50%, -50%) scale(0);
}

.insect img {
    width: 80px;
    height: 80px;
}