html { box-sizing: border-box; }
*, ::before, ::after { box-sizing: inherit; margin: 0; padding: 0; }

body {
    background-color: #111;
    display: grid;
    place-content: center;
    height: 100vh;
}

.container {
    display: grid;
    gap: 2px;
    grid-template-columns: repeat(18, 1fr);
}

.square {
    background-color: #2b2b2b;
    box-shadow: 0 0 2px #000;
    height: 16px;
    width: 16px;
    transition: 2s ease;
}

.square:hover {
    transition-duration: 0s;
}