:root {
    --background: #001;
    --color: #fff;
    --primary: coral;
    --system-font: system-ui, sans-serif;
    --monospace-font: ui-monospace, 'Cascadia Code', 'Source Code Pro', Menlo, Consolas, 'DejaVu Sans Mono', monospace;
    --serif-font: Didot, 'Bodoni MT', 'Noto Serif Display', 'Palladio L', P052, Sylfaen, serif;
}

html,
body {
    margin: 0;
    padding: 0;
    background: var(--background);
    color: var(--color);
    font-family: var(--system-font);
    font-size: 112.5%;
}

*,
*::before,
*::after {
    box-sizing: border-box;
}

.relative {
    display: grid;
    place-content: center;
    height: 100vh;
    line-height: 1.5;
    font-size: calc(20vmin / 3);
    font-family: var(--serif-font);
    padding: 3ch;
    position: relative;
}

.relative::after {
    content: "\2B63";
    position: absolute;
    bottom: 0;
    left: 50%;
    transform: translateX(-50%);
}

.ruler {
    color: var(--primary);

    &:not(.ruler--before-line)::before, &.ruler--before-line::after {
        content: "";
        display: inline-block;
        width: .1em;
        height: var(--ruler-height);
        background: currentColor;
    }

    &:not(.ruler--before-line)::after, &.ruler--before-line::before {
        font-family: var(--monospace-font);
        font-size: 1ex;
        content: var(--ruler-label);
    }

    &:not(.ruler--before-line)::after {
        padding-inline-start: .25em;
    }

    &.ruler--before-line::before {
        padding-inline-end: .25em;
    }
}

.ex {
    --ruler-height: 1ex;
    --ruler-label: "1ex";
}

.cap {
    --ruler-height: 1cap;
    --ruler-label: "1cap";
    margin-inline-start: -2.3ch;
}

.em {
    --ruler-height: 1em;
    --ruler-label: "1em";
}

.lh {
    --ruler-height: 1lh;
    --ruler-label: "1lh";

    &::before {
        vertical-align: bottom;
    }
}