style.css

@import url('https://fonts.googleapis.com/css2?family=Noto+Sans+KR:wght@100;300;500;700;900&display=swap');

:root {
    --font-size: 10px;
    --grid-column: 80;
    --grid-row: 80;
}
* {
    font-family: 'Noto Sans KR', sans-serif;
    padding: 0;
    margin: 0;
    background-color: black;
    color: white;
}
body {
    width: 100%;
    height: 100%;
}
#content {
    width: 100%;
    white-space: pre-wrap;
    line-height: 1;
    display: grid;
    grid-template-columns: repeat(var(--grid-column), 1fr);
    grid-template-rows: repeat(var(--grid-row), 1fr);
}
#content *::selection {
    background: pink;
    color: lightseagreen;
}

.cell {
    width: var(--font-size);
    height: var(--font-size);
    font-size: var(--font-size);
    letter-spacing: calc(var(--font-size) / 100 * 8);
    text-align: center;
    display: block;
}
button {
    position: fixed;
    bottom: 30px;
    left: 50%;
    transform: translateX(-50%);
    border-radius: 50%;
    height: 100px;
    width: 100px;
    font-size: 25px;
    background-color: black;
    color: white;
    box-shadow: 0px 0px 10px rgb(255 255 255 /50%);
    border-style: solid;
}
button::after {
    content: 'PLAY';
}
button.captured {
    background-color: white;
    color: black;
    box-shadow: none;
}
button.captured::after {
    content: 'STOP';
}

video,
canvas {
    display: none;
}