style.css

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

body {
    background-color: red;
    overflow: hidden;
}

.gameContainer {
    width: 100%;
    height: 100vh;
    background-size: 100vw 100vh;
    background-image: url(7486.jpg);
    background-repeat: no-repeat;
}

.thief {
    background-image: url(thief.png);
    background-repeat: none;
    background-size: cover;
    width: 232px;
    height: 218px;
    position: absolute;
    bottom: 0;
    left: 20px;
}

.gameOver {
    position: relative;
    font-size: 80px;
    font-weight: bolder;
    visibility: hidden;
    text-align: center;
    color: white;
    top: 50%;
}

#scoreCount {
    position: absolute;
    right: 45px;
    top: 31px;
    color: white;
    border: 2px solid rgb(0, 0, 0);
    padding: 10px;
}

.police {
    background-image: url(police.png);
    background-repeat: none;
    background-size: cover;
    width: 300px;
    height: 180px;
    position: absolute;
    bottom: 0;
    left: 60vw;
}

.animatethief {
    animation: animatethief 0.6s linear;
}

@keyframes animatethief {
    from {
        bottom: 0;
    }
    50% {
        bottom: 422px;
    }
    to {
        bottom: 0;
    }
}

.policeAni {
    animation: policeAni 5s linear infinite;
}

@keyframes policeAni {
    from {
        left: 100vw;
    }
    to {
        left: -10vw;
    }
}