style.css

* {
    box-sizing: border-box;
}

body {
    background: url('background.jpg') no-repeat center center fixed;
    background-size: cover;
}

#wrapper {
    position: relative;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
}

#game {
    position: relative;
    display: inline-grid;
    background: black;
}

.game-status {
    position: absolute;
    top: 0;
    left: 0;
    display: flex;
    align-items: center;
    justify-content: center;
    width: 100%;
    height: 50px;
    border: 5px darkblue solid;
    background: black;
    color: white;
    font-family: Arial, Helvetica, sans-serif;
    font-size: 1.5rem;
}

#score {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 200px;
    height: 50px;
    border: 5px darkblue solid;
    background: black;
    margin-top: 20px;
    color: white;
    font-family: Arial, Helvetica, sans-serif;
    font-size: 2rem;
}

#start-button {
    margin-top: 20px;
}

.hide {
    display: none;
}

.square {
    display: block;
}

.blank {
    background: black;
}

.wall {
    border: 1px solid blue;
}

.dot {
    background: white;
    border: 8px solid black;
    border-radius: 50%;
}

.pill {
    background: white;
    border: 5px solid black;
    border-radius: 50%;
}

.ghost {
    position: relative;
    border-radius: 10px 10px 2px 2px;
    border: none;
}

.ghost::before {
    content: '';
    display: block;
    position: absolute;
    width: 3px;
    height: 3px;
    background: black;
    border-radius: 50%;
    left: 3px;
    top: 5px;
    border: 2px solid white;
}

.ghost::after {
    content: '';
    display: block;
    position: absolute;
    width: 3px;
    height: 3px;
    background: black;
    border-radius: 50%;
    right: 3px;
    top: 5px;
    border: 2px solid white;
}

.scared {
    background: blue !important;
}

.blinky {
    background: red;
}

.pinky {
    background: pink;
}

.inky {
    background: cyan;
}

.clyde {
    background: orange;
}

.pacman {
    background: yellow;
    border: none;
    border-radius: 50%;
    clip-path: polygon(
            0 0,
            20px 0,
            20px -5px,
            8px 10px,
            20px 25px,
            20px 20px,
            0 20px
    );
    animation: chew 0.2s linear forwards infinite;
}

@keyframes chew {
    50% {
        clip-path: polygon(
                0 0,
                20px 0,
                20px 10px,
                8px 10px,
                20px 10px,
                20px 20px,
                0 20px
        );
    }
}