/* oath.moonlight.pm: neutral ink and paper, one brass accent from the
   seal's metal. Public Sans for reading, Barlow Condensed for the few
   display lines, JetBrains Mono for everything typed at a machine. */

@font-face {
    font-family: "Public Sans";
    src: url("/fonts/PublicSans.woff2") format("woff2");
    font-weight: 400 700;
    font-style: normal;
    font-display: swap;
}

@font-face {
    font-family: "Public Sans";
    src: url("/fonts/PublicSans-Italic.woff2") format("woff2");
    font-weight: 400;
    font-style: italic;
    font-display: swap;
}

@font-face {
    font-family: "Barlow Condensed";
    src: url("/fonts/BarlowCondensed-600.woff2") format("woff2");
    font-weight: 600;
    font-style: normal;
    font-display: swap;
}

@font-face {
    font-family: "JetBrains Mono";
    src: url("/fonts/JetBrainsMono.woff2") format("woff2");
    font-weight: 400 600;
    font-style: normal;
    font-display: swap;
}

:root {
    color-scheme: light dark;
    --ground: #fbfbfa;
    --raised: #f0f0ee;
    --code-ground: #f5f5f3;
    --ink: #17171a;
    --muted: #55555c;
    --faint: #85858c;
    --line: #e2e2df;
    --rule: #cbcbc6;
    --accent: #866626;
    --sans: "Public Sans", "Helvetica Neue", Arial, sans-serif;
    --display: "Barlow Condensed", "Arial Narrow", sans-serif;
    --mono: "JetBrains Mono", ui-monospace, "SF Mono", Menlo, Consolas, monospace;
    --measure: 46rem;
    --page: 78rem;
    --header: 3.5rem;
}

@media (prefers-color-scheme: dark) {
    :root {
        --ground: #0f0f11;
        --raised: #1a1a1d;
        --code-ground: #151518;
        --ink: #ebebe8;
        --muted: #a6a6ad;
        --faint: #76767e;
        --line: #29292d;
        --rule: #3b3b40;
        --accent: #d2b483;
    }
}

* { box-sizing: border-box; }

html {
    -webkit-text-size-adjust: 100%;
}

body {
    margin: 0;
    background: var(--ground);
    color: var(--ink);
    font-family: var(--sans);
    font-size: 1.0625rem;
    line-height: 1.62;
    -webkit-font-smoothing: antialiased;
}

a {
    color: var(--ink);
    text-decoration-color: var(--accent);
    text-decoration-thickness: 1px;
    text-underline-offset: 0.2em;
}

a:hover { color: var(--accent); }

a:focus-visible,
summary:focus-visible {
    outline: 2px solid var(--accent);
    outline-offset: 2px;
    border-radius: 2px;
}

::selection {
    background: var(--accent);
    color: var(--ground);
}

h1, h2, h3, h4, h5, h6 {
    line-height: 1.2;
    font-weight: 650;
}

[id] {
    scroll-margin-top: calc(var(--header) + 1rem);
}

strong { font-weight: 650; }

code,
pre {
    font-family: var(--mono);
    font-variant-ligatures: none;
}

code {
    font-size: 0.84em;
    background: var(--raised);
    padding: 0.08em 0.3em;
    border-radius: 3px;
    overflow-wrap: break-word;
}

pre {
    font-size: 0.82rem;
    line-height: 1.6;
    margin: 1rem 0 1.25rem;
    padding: 0.9rem 1.1rem;
    background: var(--code-ground);
    border: 1px solid var(--line);
    border-radius: 4px;
    overflow-x: auto;
    tab-size: 4;
}

pre code {
    background: none;
    padding: 0;
    font-size: inherit;
    overflow-wrap: normal;
}

pre .comment { color: var(--faint); }
pre .line { display: block; }
pre .prompt { color: var(--accent); }
pre .cmd { font-weight: 600; }

.seal {
    display: block;
    fill: currentColor;
    flex: none;
}

.skip {
    position: absolute;
    left: 1rem;
    top: -3rem;
    padding: 0.4rem 0.8rem;
    background: var(--ink);
    color: var(--ground);
    z-index: 20;
}

.skip:focus { top: 0.5rem; }

/* Site header and footer */

header.site {
    position: sticky;
    top: 0;
    z-index: 10;
    height: var(--header);
    background: color-mix(in srgb, var(--ground) 92%, transparent);
    backdrop-filter: blur(8px);
    border-bottom: 1px solid var(--line);
}

header.site nav {
    max-width: var(--page);
    height: 100%;
    margin: 0 auto;
    padding: 0 1.5rem;
    display: flex;
    align-items: center;
    gap: 1.75rem;
    font-size: 0.9375rem;
}

header.site nav a {
    color: var(--muted);
    text-decoration: none;
    padding: 0.75rem 0;
}

header.site nav a:hover,
header.site nav a[aria-current] {
    color: var(--ink);
}

header.site nav a[aria-current] {
    text-decoration: underline;
    text-decoration-color: var(--accent);
    text-decoration-thickness: 2px;
    text-underline-offset: 0.45em;
}

header.site .brand {
    display: flex;
    align-items: center;
    gap: 0.6rem;
    margin-right: auto;
    color: var(--ink);
}

header.site .brand .seal {
    width: 1.75rem;
    height: 1.75rem;
}

header.site .brand span {
    font-family: var(--display);
    font-weight: 600;
    font-size: 1.35rem;
    letter-spacing: 0.16em;
    text-transform: uppercase;
    line-height: 1;
    padding-top: 0.1rem;
}

footer.site {
    border-top: 1px solid var(--line);
    margin-top: 4.5rem;
}

footer.site div {
    max-width: var(--page);
    margin: 0 auto;
    padding: 1.5rem;
    display: flex;
    flex-wrap: wrap;
    justify-content: space-between;
    gap: 0.5rem 2rem;
    font-size: 0.875rem;
    color: var(--muted);
}

footer.site p { margin: 0; }

footer.site a { color: var(--muted); }

.principles {
    font-family: var(--display);
    font-weight: 600;
    font-size: 0.95rem;
    letter-spacing: 0.12em;
    text-transform: uppercase;
    color: var(--faint);
}

/* Home */

.home {
    max-width: calc(var(--measure) + 3rem);
    margin: 0 auto;
    padding: 0 1.5rem;
}

.home section {
    margin-top: 4rem;
}

.home h2 {
    font-family: var(--display);
    font-weight: 600;
    font-size: 2rem;
    letter-spacing: 0.01em;
    line-height: 1.1;
    margin: 0 0 1.1rem;
    padding-top: 1.1rem;
    border-top: 1px solid var(--rule);
}

.home h3 {
    font-size: 1.1rem;
    margin: 2.25rem 0 0.5rem;
}

.intro {
    padding: 4rem 0 0.5rem;
}

.intro .title {
    display: flex;
    align-items: center;
    gap: 1.1rem;
    margin: 0 0 1.4rem;
}

.intro .title .seal {
    width: 4.75rem;
    height: 4.75rem;
}

.intro h1 {
    font-family: var(--display);
    font-weight: 600;
    font-size: 5.25rem;
    line-height: 0.85;
    letter-spacing: 0.1em;
    text-transform: uppercase;
    margin: 0;
    padding-top: 0.08em;
}

.intro h1.plain {
    font-size: 2.5rem;
    letter-spacing: 0.02em;
    text-transform: none;
    margin-bottom: 1rem;
}

.lede {
    font-size: 1.25rem;
    line-height: 1.5;
    margin: 0 0 1.25rem;
}

.facts {
    display: flex;
    flex-wrap: wrap;
    gap: 0.35rem 1.25rem;
    font-size: 0.9rem;
    color: var(--muted);
    margin: 0;
}

.facts a {
    font-weight: 600;
    padding: 0.2rem 0;
}

#goals p strong {
    font-weight: 700;
}

/* The catalog: eight kinds, a ledger with canto's counts. */

.table-wrap {
    overflow-x: auto;
    margin: 1rem 0 1.5rem;
}

.kinds {
    width: 100%;
    border-collapse: collapse;
}

.kinds thead th {
    font-size: 0.72rem;
    font-weight: 600;
    letter-spacing: 0.09em;
    text-transform: uppercase;
    color: var(--faint);
    text-align: left;
    padding: 0 1rem 0.5rem 0;
    border-bottom: 1px solid var(--rule);
}

.kinds tbody th,
.kinds td {
    vertical-align: top;
    padding: 0.85rem 1rem 0.85rem 0;
    border-bottom: 1px solid var(--line);
}

.kinds tbody th {
    text-align: left;
    width: 5.5rem;
}

.kinds tbody th code {
    background: none;
    padding: 0;
    font-size: 1.1rem;
    font-weight: 600;
}

.kinds .ids {
    display: block;
    margin-top: 0.3rem;
    font-family: var(--mono);
    font-size: 0.78rem;
    color: var(--faint);
    overflow-wrap: anywhere;
}

.kinds .count {
    text-align: right;
    padding-right: 0;
    width: 5rem;
}

.kinds td.count {
    font-family: var(--display);
    font-weight: 600;
    font-size: 2.1rem;
    line-height: 1;
    font-variant-numeric: tabular-nums;
    color: var(--accent);
    padding-top: 0.7rem;
}

/* What works */

.features {
    margin: 0;
}

.features > div {
    display: grid;
    grid-template-columns: 8.5rem minmax(0, 1fr);
    gap: 0 1.25rem;
    padding: 0.65rem 0;
    border-bottom: 1px solid var(--line);
}

.features dt {
    font-weight: 650;
    font-size: 0.95rem;
    padding-top: 0.1rem;
}

.features dt code {
    background: none;
    padding: 0;
    font-size: 0.92em;
}

.features dd {
    margin: 0;
}

.more {
    margin-top: 1rem;
    color: var(--muted);
}

#status ul {
    padding-left: 1.25rem;
}

#status li {
    margin: 0.3rem 0;
}

/* Manual */

.manual {
    max-width: var(--page);
    margin: 0 auto;
    padding: 0 1.5rem;
    display: grid;
    grid-template-columns: 16.5rem minmax(0, 1fr);
    gap: 3rem;
}

.contents {
    position: sticky;
    top: var(--header);
    align-self: start;
    max-height: calc(100vh - var(--header));
    overflow-y: auto;
    padding: 2rem 0.5rem 2rem 0;
    font-size: 0.85rem;
    line-height: 1.4;
}

.contents-title {
    font-size: 0.72rem;
    font-weight: 600;
    letter-spacing: 0.09em;
    text-transform: uppercase;
    color: var(--faint);
    margin: 0 0 0.75rem;
}

.toc,
.toc ol {
    list-style: none;
    margin: 0;
    padding: 0;
}

.toc > li {
    margin-bottom: 0.9rem;
}

.toc > li > a {
    font-weight: 650;
    color: var(--ink);
}

.toc ol {
    margin-top: 0.2rem;
}

.toc a {
    display: flex;
    gap: 0.5rem;
    padding: 0.12rem 0;
    color: var(--muted);
    text-decoration: none;
}

.toc a:hover {
    color: var(--accent);
}

.toc .number {
    flex: none;
    min-width: 2.1rem;
    color: var(--faint);
    font-variant-numeric: tabular-nums;
}

.toc code {
    font-size: 0.92em;
    background: none;
    padding: 0;
}

.manual-body {
    min-width: 0;
    max-width: var(--measure);
    padding: 2rem 0;
}

.manual-head h1 {
    font-family: var(--display);
    font-weight: 600;
    font-size: 2.75rem;
    letter-spacing: 0.01em;
    line-height: 1;
    margin: 0.5rem 0 1rem;
}

.manual-head p {
    color: var(--muted);
    margin: 0 0 1rem;
}

.contents-inline {
    display: none;
    border: 1px solid var(--line);
    border-radius: 4px;
    padding: 0.5rem 0.9rem;
    font-size: 0.9rem;
}

.contents-inline summary {
    cursor: pointer;
    font-weight: 650;
    padding: 0.35rem 0;
}

.contents-inline .toc {
    margin-top: 0.75rem;
}

.chapter h2 {
    font-family: var(--display);
    font-weight: 600;
    font-size: 2.1rem;
    letter-spacing: 0.01em;
    line-height: 1.1;
    margin: 3.5rem 0 1rem;
    padding-top: 1.25rem;
    border-top: 2px solid var(--rule);
}

.chapter h3 {
    font-size: 1.3rem;
    margin: 2.5rem 0 0.75rem;
}

.chapter h4 {
    font-size: 1.1rem;
    margin: 2rem 0 0.6rem;
}

.chapter h5,
.chapter h6 {
    font-size: 1rem;
    margin: 1.5rem 0 0.5rem;
}

.chapter :is(h2, h3, h4) code {
    background: none;
    padding: 0;
    font-size: 0.85em;
}

.chapter .number {
    color: var(--faint);
    font-weight: 500;
    margin-right: 0.55em;
    font-variant-numeric: tabular-nums;
}

.chapter h2 .number {
    color: var(--accent);
    font-weight: 600;
}

.anchor {
    margin-left: 0.4em;
    color: var(--faint);
    text-decoration: none;
    font-weight: 400;
    opacity: 0;
}

h2:hover .anchor,
h3:hover .anchor,
h4:hover .anchor,
h5:hover .anchor,
.anchor:focus-visible {
    opacity: 1;
}

.chapter ul,
.chapter ol {
    padding-left: 1.4rem;
}

.chapter li {
    margin: 0.25rem 0;
}

.chapter li > pre {
    margin: 0.5rem 0 0.75rem;
}

.chapter blockquote {
    margin: 1rem 0;
    padding: 0.1rem 0 0.1rem 1rem;
    border-left: 3px solid var(--accent);
    color: var(--muted);
}

.chapter table {
    border-collapse: collapse;
    width: 100%;
    font-size: 0.92rem;
    line-height: 1.45;
}

.chapter th,
.chapter td {
    text-align: left;
    vertical-align: top;
    padding: 0.45rem 0.75rem 0.45rem 0;
    border-bottom: 1px solid var(--line);
}

.chapter th {
    font-weight: 650;
    font-size: 0.85rem;
    color: var(--muted);
    border-bottom: 1px solid var(--rule);
}

.chapter td code {
    font-size: 0.84em;
}

@media (min-width: 40rem) {
    .chapter td:first-child code {
        white-space: nowrap;
    }
}

/* Narrow screens: contents fold into the page; 16px gutters. */

@media (max-width: 60rem) {
    .manual {
        display: block;
        padding: 0 1rem;
    }

    .contents {
        display: none;
    }

    .contents-inline {
        display: block;
    }
}

@media (max-width: 40rem) {
    body {
        font-size: 1rem;
    }

    header.site nav {
        padding: 0 1rem;
        gap: 1.1rem;
    }

    .home {
        padding: 0 1rem;
    }

    .intro {
        padding-top: 2.5rem;
    }

    .intro .title .seal {
        width: 3.5rem;
        height: 3.5rem;
    }

    .intro h1 {
        font-size: 3.9rem;
    }

    .lede {
        font-size: 1.1rem;
    }

    .home h2 {
        font-size: 1.75rem;
    }

    .features > div {
        grid-template-columns: minmax(0, 1fr);
    }

    .kinds tbody th {
        width: 4rem;
    }

    .kinds .count {
        width: 3.25rem;
    }

    .kinds td.count {
        font-size: 1.6rem;
    }

    pre {
        font-size: 0.78rem;
        padding: 0.75rem 0.85rem;
    }

    /* The home page's samples wrap rather than hide behind a sideways
       scroll; a wrapped terminal line hangs under its first characters.
       The manual's code keeps its columns and scrolls. */
    .home pre,
    .home pre code {
        white-space: pre-wrap;
        overflow-wrap: anywhere;
    }

    .home pre .line {
        padding-left: 2ch;
        text-indent: -2ch;
    }

    .home pre .h4 { padding-left: 4ch; text-indent: -4ch; }
    .home pre .h6 { padding-left: 6ch; text-indent: -6ch; }
    .home pre .h8 { padding-left: 8ch; text-indent: -8ch; }

    footer.site div {
        padding: 1.25rem 1rem;
    }
}