/**
 * Halo Refined: the reading face.
 *
 * Halo is still Mono everywhere — every control, label, badge, overline and
 * paragraph. This adds a second, *reading* face (Instrument Serif, weight 400)
 * for reading moments only: page h1s, app names, section h2/h3s and the big
 * email link. Where a serif line has two halves, the second is italic and
 * muted. Theme-independent: colours come from tokens.css.
 *
 * Ported from the Halo Refined design system's tokens/reading.css and
 * fonts/fonts.css, trimmed to the values the site sets.
 */

@font-face {
    font-family: "Instrument Serif";
    font-style: normal;
    font-weight: 400;
    font-display: swap;
    src: url("/halo/fonts/InstrumentSerif-Regular.ttf") format("truetype");
}

@font-face {
    font-family: "Instrument Serif";
    font-style: italic;
    font-weight: 400;
    font-display: swap;
    src: url("/halo/fonts/InstrumentSerif-Italic.ttf") format("truetype");
}

:root {
    --halo-font-serif: "Instrument Serif", "Iowan Old Style", Georgia, serif;

    /* Serif scale. */
    --halo-serif-xs: 17px;
    --halo-serif-sm: 22px;
    --halo-serif-md: 26px;
    --halo-serif-lg: 30px;
    --halo-serif-xl: 44px;
    --halo-serif-2xl: 48px;
    --halo-serif-3xl: 56px;
    --halo-serif-4xl: 60px;
    --halo-serif-5xl: 72px;

    --halo-tracking-serif: -0.02em;
    --halo-leading-display: 0.95;

    /* Overline: mono, uppercase, one line. */
    --halo-text-overline: 10.5px;

    /* Paper: the system's only texture, a dot grid. */
    --halo-paper-pitch: 14px;
    --halo-paper-dot: 0.9px;
}