/* ============================================================
   Beige Papers — papers.css
   Essay layer for the long-form "expedition" documents.
   Loads ON TOP of styles-v3.css and reuses its tokens; every
   rule is scoped under .paper so it never touches the rest of
   the site (which centers h1/h2 as a masthead — essays don't).
   ============================================================ */

.paper {
    --gold:       #9a7b12;
    --gold-bg:    #f7efd6;
    --gold-rule:  #d8bf6a;
    --steel:      #345a9e;
    --steel-bg:   #e7edf6;
    /* clear the absolutely-positioned back icon that sits at the top-left */
    padding-top: 3.75rem;
}

/* ---------- Cover ---------- */
.paper .cover {
    border-bottom: 2px solid var(--rule-bold);
    padding-bottom: 2rem;
    margin-bottom: 2.6rem;
}
.paper .kicker {
    font-family: var(--font-meta);
    text-transform: uppercase;
    letter-spacing: 0.16em;
    font-size: 0.72rem;
    color: var(--accent);
    margin-bottom: 1.1rem;
}
.paper h1 {
    text-align: left;
    font-size: 2.9rem;
    line-height: 1.06;
    letter-spacing: -0.02em;
    font-weight: 600;
    margin: 0 0 0.5rem;
}
.paper .sub {
    text-align: left;
    font-family: var(--font-body);
    font-style: italic;
    font-size: 1.3rem;
    line-height: 1.4;
    color: var(--ink-soft);
    margin: 0 0 1.4rem;
}
.paper .byline {
    font-family: var(--font-meta);
    font-size: 0.76rem;
    line-height: 1.6;
    color: var(--ink-soft);
}
.paper .byline em { font-style: italic; font-family: var(--font-body); }

/* ---------- Disclaimer / legend ---------- */
.paper .disclaimer {
    background: var(--paper-edge);
    border-left: 3px solid var(--accent);
    padding: 1.1rem 1.3rem;
    margin-top: 1.6rem;
    font-size: 0.95rem;
    line-height: 1.55;
    color: var(--ink-soft);
}
.paper .disclaimer strong { color: var(--ink); }
.paper .legend {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
    margin-top: 0.9rem;
    font-family: var(--font-meta);
    font-size: 0.7rem;
}
.paper .legend span { padding: 0.15rem 0.6rem; border-radius: 2px; }

/* ---------- Section headings (I, II, …) ---------- */
.paper h2 {
    text-align: left;
    font-family: var(--font-display);
    font-weight: 560;
    font-size: 1.5rem;
    letter-spacing: -0.01em;
    line-height: 1.15;
    color: var(--ink);
    margin: 3rem 0 0.7rem;
    padding-top: 1.1rem;
    border-top: 1px solid var(--rule);
}
.paper h2 .num {
    font-family: var(--font-meta);
    font-size: 0.9rem;
    font-weight: 400;
    color: var(--accent);
    margin-right: 0.7em;
    vertical-align: 0.12em;
}

/* ---------- Lead paragraph ---------- */
.paper .lead {
    font-size: 1.28rem;
    line-height: 1.5;
    color: var(--ink);
}

/* ---------- Display math ----------
   .math  — literal Unicode multi-line derivations (kept as text)
   .eqn   — a single equation rendered by the traction engine        */
.paper .math,
.paper .eqn {
    background: var(--paper-edge);
    border-left: 3px solid var(--accent);
    padding: 0.9rem 1.2rem;
    margin: 1.6rem 0;
    overflow-x: auto;
}
.paper .math {
    font-family: var(--font-math);
    white-space: pre;
    font-size: 1.05rem;
    line-height: 1.85;
    color: var(--ink);
}
.paper .eqn { text-align: center; }
.paper .eqn .expression { margin: 0.3rem; }

/* ---------- Inline math ---------- */
.paper .math-inline {
    font-family: var(--font-math);
    font-size: 0.98em;
    white-space: nowrap;
}

/* ---------- Confidence tags ---------- */
.paper .conf {
    font-family: var(--font-meta);
    font-size: 0.62rem;
    font-weight: 500;
    text-transform: uppercase;
    letter-spacing: 0.08em;
    display: inline-block;
    padding: 0.1rem 0.5rem;
    border-radius: 2px;
    vertical-align: 0.15em;
    white-space: nowrap;
}
.paper .c-solid,
.paper .c-proven    { background: var(--paper-edge); color: var(--accent); border: 1px solid color-mix(in srgb, var(--accent) 30%, transparent); }
.paper .c-plausible { background: var(--steel-bg);   color: var(--steel); }
.paper .c-wild      { background: var(--gold-bg);    color: var(--gold);  border: 1px solid var(--gold-rule); }

/* A badge that links to its proof: kill the default link underline, keep the pill */
.paper a.conf {
    text-decoration: none;
    cursor: help;
    transition: filter 0.12s ease;
}
.paper a.conf:hover,
.paper a.conf:focus { filter: brightness(0.94); }
.paper a.c-proven,
.paper a.c-solid { border: 1px solid color-mix(in srgb, var(--accent) 30%, transparent); }

/* ---------- Citation popover (see lib/popover.js) ---------- */
.cite-popover {
    position: absolute;
    top: 0;
    left: 0;
    z-index: 50;
    max-width: 20rem;
    padding: 0.7rem 0.85rem;
    background: var(--paper);
    color: var(--ink);
    border: 1px solid var(--rule-bold);
    border-radius: 3px;
    box-shadow: 0 6px 22px -10px rgba(35, 32, 27, 0.45);
    font-family: var(--font-body);
    font-size: 0.82rem;
    line-height: 1.5;
    pointer-events: none;
    opacity: 0;
    visibility: hidden;
    transform: translateY(3px);
    transition: opacity 0.13s ease, transform 0.13s ease, visibility 0.13s;
}
.cite-popover.is-visible {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
}
.cite-popover .cite-head {
    display: inline;
    font-family: var(--font-meta);
    text-transform: uppercase;
    letter-spacing: 0.08em;
    font-size: 0.6rem;
    font-weight: 500;
    color: var(--accent);
    margin-right: 0.35em;
}
.cite-popover cite {
    display: block;
    margin-top: 0.5rem;
    padding-top: 0.45rem;
    border-top: 1px solid var(--rule);
    font-size: 0.76rem;
    color: var(--ink-soft);
}
/* the popover lives outside .paper, so re-apply the inline-math font here */
.cite-popover .math-inline {
    font-family: var(--font-math);
    white-space: nowrap;
}
/* arrow */
.cite-popover::after {
    content: "";
    position: absolute;
    left: var(--arrow-x, 50%);
    width: 9px;
    height: 9px;
    margin-left: -5px;
    background: var(--paper);
    border: 1px solid var(--rule-bold);
    transform: rotate(45deg);
}
.cite-popover:not(.below)::after {
    bottom: -5px;
    border-top: none;
    border-left: none;
}
.cite-popover.below::after {
    top: -5px;
    border-bottom: none;
    border-right: none;
}

/* ---------- Pull-quote ---------- */
.paper .pull {
    font-family: var(--font-display);
    font-style: italic;
    font-weight: 380;
    font-size: 1.5rem;
    line-height: 1.32;
    color: var(--accent);
    margin: 2.4rem 0;
    padding-left: 1.2rem;
    border-left: 3px solid var(--accent);
}

/* ---------- Aside ---------- */
.paper .aside {
    background: var(--paper-edge);
    border-left: 3px solid var(--rule-bold);
    padding: 1.1rem 1.3rem;
    margin: 1.8rem 0;
    font-size: 1rem;
    line-height: 1.55;
}
.paper .aside .tag {
    font-family: var(--font-meta);
    text-transform: uppercase;
    letter-spacing: 0.1em;
    font-size: 0.66rem;
    color: var(--accent);
    display: block;
    margin-bottom: 0.5rem;
}

/* ---------- Footer ---------- */
.paper .foot {
    margin-top: 4rem;
    padding-top: 1.4rem;
    border-top: 1px solid var(--rule);
    font-family: var(--font-meta);
    font-size: 0.76rem;
    line-height: 1.7;
    color: var(--ink-soft);
}
.paper .foot strong { color: var(--ink); }
.paper .foot em { font-family: var(--font-body); }

/* ---------- Book-chapter chrome ---------- */
.paper .chapter-meta {
    font-family: var(--font-meta);
    text-transform: uppercase;
    letter-spacing: 0.14em;
    font-size: 0.72rem;
    color: var(--ink-soft);
    margin-bottom: 1rem;
}
.paper .chapter-meta .part { color: var(--accent); }

/* footnote references + list (the candor channel) */
.paper sup.fnref { font-size: 0.66em; }
.paper sup.fnref a { border-bottom: none; font-family: var(--font-meta); }
.paper .footnotes {
    margin-top: 3rem;
    padding-top: 1.2rem;
    border-top: 1px solid var(--rule);
    font-size: 0.92rem;
    color: var(--ink-soft);
}
.paper .footnotes ol { padding-left: 1.4rem; }
.paper .footnotes li { margin: 0.6rem 0; }

/* prev / next / contents nav */
.chapter-nav {
    display: flex;
    justify-content: space-between;
    align-items: baseline;
    gap: 1rem;
    margin-top: 3.5rem;
    padding-top: 1.3rem;
    border-top: 2px solid var(--rule-bold);
    font-family: var(--font-meta);
    font-size: 0.82rem;
}
.chapter-nav a { border-bottom: none; }
.chapter-nav .prev::before { content: "\2190\00a0"; }   /* ←  */
.chapter-nav .next::after  { content: "\00a0\2192"; }   /* →  */
.chapter-nav .toc { color: var(--ink-soft); }

/* ---------- Table of contents (landing page) ---------- */
.paper .toc-part {
    font-family: var(--font-meta);
    text-transform: uppercase;
    letter-spacing: 0.12em;
    font-size: 0.74rem;
    color: var(--accent);
    margin: 2.6rem 0 0.4rem;
    padding-bottom: 0.4rem;
    border-bottom: 1px solid var(--rule);
}
.paper ol.contents { list-style: none; padding: 0; margin: 0; }
.paper ol.contents li {
    display: grid;
    grid-template-columns: 2.4rem 1fr;
    column-gap: 0.8rem;
    padding: 0.7rem 0;
    border-bottom: 1px solid var(--rule);
    align-items: baseline;
    margin: 0;
}
.paper ol.contents .ch-num {
    font-family: var(--font-meta);
    font-size: 0.82rem;
    color: var(--ink-soft);
    text-align: right;
}
.paper ol.contents .ch-title {
    font-family: var(--font-display);
    font-weight: 560;
    font-size: 1.1rem;
    letter-spacing: -0.01em;
}
.paper ol.contents .ch-title a { border-bottom: none; }
.paper ol.contents .ch-sub {
    grid-column: 2;
    color: var(--ink-soft);
    font-size: 0.95rem;
    margin-top: 0.1rem;
}
.paper ol.contents li.soon { opacity: 0.5; }
.paper ol.contents .soon-tag {
    font-family: var(--font-meta);
    font-size: 0.58rem;
    text-transform: uppercase;
    letter-spacing: 0.1em;
    color: var(--ink-soft);
    border: 1px solid var(--rule);
    border-radius: 2px;
    padding: 0.05em 0.4em;
    margin-left: 0.5em;
    vertical-align: 0.18em;
}

/* ---------- Mobile ---------- */
@media only screen and (max-width: 640px) {
    .paper h1 { font-size: 2.1rem; }
    .paper .sub { font-size: 1.12rem; }
    .paper .lead { font-size: 1.14rem; }
}