/* Reading room: the shared layout for every page in the Reading shelf.
   One serif text column at a comfortable measure, a quiet contents rail
   that follows along, and figures drawn with hairlines and the one rust
   accent. Works in paper and night paper through papers.css tokens. */

.collection-subpage .article-page {
    --rail: 168px;
    --rail-gap: 56px;
    --measure: 680px;
    width: min(100% - 64px, calc(var(--rail) + var(--rail-gap) + var(--measure)));
}
.collection-subpage .article-page--single { width: min(100% - 64px, var(--measure)); }

/* ---------------------------------------------------------------- header */

.article-page > .page-header {
    margin-left: calc(var(--rail) + var(--rail-gap));
    margin-bottom: 44px;
    padding-bottom: 30px;
    border-bottom: 1px solid var(--border);
}
.article-page--single > .page-header { margin-left: 0; }
.collection-subpage .article-page .page-title { font-size: clamp(32px, 3.6vw, 42px); line-height: 1.12; }
.article-page .page-header > .eyebrow,
.article-kicker {
    display: block;
    margin-bottom: 12px;
    color: var(--brand);
    font: 500 11px/1.4 var(--font-mono);
    letter-spacing: .12em;
    text-transform: uppercase;
}
.article-meta {
    display: flex;
    flex-wrap: wrap;
    gap: 4px 10px;
    margin-top: 16px;
    color: var(--subtle-foreground);
    font: 400 11px/1.6 var(--font-mono);
    letter-spacing: .04em;
}
.article-meta > * + *::before { content: "·"; margin-right: 10px; color: var(--border-strong); }
.article-meta .doc-stamp { margin-right: 6px; padding: 1px 7px 0; border-width: 1px; font-size: 10px; letter-spacing: .14em; }
.article-meta > .doc-stamp + *::before { content: none; }
.standfirst {
    margin-top: 14px;
    color: var(--muted-foreground);
    font: italic 400 21px/1.5 var(--font-serif);
    letter-spacing: -.01em;
}

/* ---------------------------------------------------------------- layout */

.article-layout {
    display: grid;
    grid-template-columns: var(--rail) minmax(0, var(--measure));
    gap: var(--rail-gap);
    align-items: start;
}

/* Contents rail: a hairline spine; the section you are reading gets rust. */
.article-contents {
    position: sticky;
    top: 32px;
    display: grid;
    gap: 2px;
    max-height: calc(100vh - 64px);
    overflow-y: auto;
    padding-top: 4px;
    scrollbar-width: none;
}
.article-contents::before {
    content: "Contents";
    margin-bottom: 10px;
    color: var(--subtle-foreground);
    font: 500 10px var(--font-mono);
    letter-spacing: .12em;
    text-transform: uppercase;
}
.article-contents a {
    display: flex;
    gap: 10px;
    padding: 6px 0 6px 14px;
    border-left: 1px solid var(--border);
    color: var(--muted-foreground);
    font-size: 13px;
    line-height: 1.45;
    text-decoration: none;
    transition: color var(--motion-fast) var(--ease-standard), border-color var(--motion-fast) var(--ease-standard);
}
.article-contents a:hover { color: var(--foreground); border-left-color: var(--border-strong); }
.article-contents a[aria-current="location"] { color: var(--foreground); border-left: 2px solid var(--brand); padding-left: 13px; }
.article-contents a span { flex: 0 0 auto; padding-top: 1px; color: var(--subtle-foreground); font: 11px/1.6 var(--font-mono); }
.article-contents a[aria-current="location"] span { color: var(--brand); }
.article-contents .toc-sub { padding-left: 28px; font-size: 12.5px; }
.article-contents .toc-sub[aria-current="location"] { padding-left: 27px; }

/* A clipping has no sections; its rail carries the source details instead. */
.article-details::before { content: "Clipping"; }
.article-details dl { display: grid; margin: 0; border-left: 1px solid var(--border); }
.article-details dl > div { padding: 7px 0 7px 14px; }
.article-details dt { color: var(--subtle-foreground); font: 500 10px/1.6 var(--font-mono); letter-spacing: .1em; text-transform: uppercase; }
.article-details dd { margin: 2px 0 0; color: var(--muted-foreground); font-size: 13px; line-height: 1.45; }
.article-details dl > div:first-child dd { color: var(--foreground); font: 400 15px/1.4 var(--font-serif); letter-spacing: -.005em; }

/* Reading progress: a rust hairline along the top edge of the viewport. */
.reading-progress {
    position: fixed;
    inset: 0 0 auto;
    z-index: 150;
    height: 2px;
    background: var(--brand);
    transform: scaleX(var(--progress, 0));
    transform-origin: left;
    pointer-events: none;
}

/* ------------------------------------------------------------------ body */

.article-body {
    min-width: 0;
    color: var(--prose);
    font: 400 18px/1.75 var(--font-serif);
    letter-spacing: -.003em;
    hanging-punctuation: first;
}
.article-body p { margin: 0 0 1.15em; text-wrap: pretty; }
.article-body .article-lead {
    margin-bottom: 1.1em;
    color: var(--foreground);
    font-size: 22px;
    line-height: 1.6;
    letter-spacing: -.012em;
}
.article-body strong { color: var(--foreground); font-weight: 700; }
.article-body a { text-decoration-color: color-mix(in srgb, var(--brand) 45%, transparent); }
.article-body a:hover { color: var(--brand); text-decoration-color: var(--brand); }
.article-body section { margin-top: 64px; scroll-margin-top: 40px; }
.article-body h2 {
    display: flex;
    align-items: baseline;
    gap: 16px;
    margin: 0 0 22px;
    color: var(--foreground);
    font: 400 30px/1.22 var(--font-serif);
    letter-spacing: -.025em;
    text-wrap: balance;
    scroll-margin-top: 40px;
}
.article-body .section-number { flex: 0 0 auto; color: var(--brand); font: 400 13px var(--font-mono); letter-spacing: .04em; transform: translateY(-4px); }
.article-body h3 {
    margin: 40px 0 12px;
    color: var(--foreground);
    font: 400 23px/1.35 var(--font-serif);
    letter-spacing: -.015em;
    scroll-margin-top: 40px;
}
.article-body ul, .article-body ol { margin: 0 0 1.15em; padding-left: 1.3em; }
.article-body li { margin-bottom: .4em; padding-left: .2em; }
.article-body li::marker { color: var(--brand); }
.article-body figure { margin: 36px 0; }
.article-body figcaption {
    margin-top: 14px;
    color: var(--muted-foreground);
    font: 400 13px/1.65 var(--font-sans);
}

/* Small-caps style sans labels inside figures, used across the shelf. */
.figure-label,
.example-steps dt,
.example-before,
.article-table caption,
.article-table thead {
    color: var(--muted-foreground);
    font-family: var(--font-sans);
}

/* ------------------------------------------------------- GTD worksheets */

.example-steps { margin: 0; border-block: 1px solid var(--border); }
.example-steps > div { display: grid; grid-template-columns: 150px minmax(0, 1fr); gap: 24px; padding: 18px 0; }
.example-steps > div + div { border-top: 1px solid var(--border); }
.example-steps dt { padding-top: 5px; font: 500 10px/1.6 var(--font-mono); letter-spacing: .1em; text-transform: uppercase; }
.example-steps > div:last-child dt { color: var(--brand); }
.example-steps dd { margin: 0; color: var(--foreground); }

/* Vague → clear pairs: the vague version struck through, the action beneath. */
.example-pairs { margin: 32px 0; border-top: 1px solid var(--border); }
.example-pairs > div { display: grid; grid-template-columns: 150px minmax(0, 1fr); gap: 24px; padding: 18px 0; border-bottom: 1px solid var(--border); }
.example-pairs p { margin: 0; }
.article-body .example-before {
    font-size: 14px;
    line-height: 1.75;
    text-decoration: line-through;
    text-decoration-color: color-mix(in srgb, var(--brand) 55%, transparent);
}
.example-pairs p:last-child { color: var(--foreground); }

.reading-list { margin: 32px 0; display: grid; grid-template-columns: 1fr 1fr; gap: 0 32px; }
.reading-list > div { padding: 16px 0 18px; border-top: 1px solid var(--border); }
.reading-list > div:last-child:nth-child(odd) { grid-column: 1 / -1; }
.reading-list dt { margin-bottom: 4px; color: var(--foreground); font: 600 13px var(--font-sans); letter-spacing: .01em; }
.reading-list dd { margin: 0; font-size: 16px; line-height: 1.6; }

/* "Try it" panels: a worksheet on a slightly raised sheet. */
.article-practice {
    margin: 40px 0;
    padding: 28px 32px 14px;
    border: 1px solid var(--border);
    border-radius: var(--radius);
    background: var(--surface);
}
.article-practice h3 { margin: 0 0 18px; font-size: 22px; }
.article-practice h3::before {
    content: "Practice";
    display: block;
    margin-bottom: 8px;
    color: var(--brand);
    font: 500 10px var(--font-mono);
    letter-spacing: .12em;
    text-transform: uppercase;
}
.article-body .article-practice ol { counter-reset: step; list-style: none; margin: 0 0 18px; padding: 0; }
.article-practice li { counter-increment: step; position: relative; margin: 0; padding: 12px 0 12px 44px; border-top: 1px solid var(--border); }
.article-practice li::before {
    content: counter(step, decimal-leading-zero);
    position: absolute;
    left: 0;
    top: 15px;
    color: var(--brand);
    font: 400 12px var(--font-mono);
}

/* -------------------------------------------------- Systems Thinking */

/* Stock & flow: two pipes feeding and draining a tank that is part full. */
.stock-flow {
    display: grid;
    grid-template-columns: minmax(0, 1fr) 168px minmax(0, 1fr);
    align-items: center;
    padding: 8px 0;
}
.flow-rate { display: grid; gap: 10px; justify-items: center; color: var(--muted-foreground); font: 400 13px/1.4 var(--font-sans); text-align: center; }
.flow-line { position: relative; display: block; width: 100%; height: 9px; font-size: 0; }
.flow-line::before { content: ""; position: absolute; left: 0; right: 4px; top: 4px; border-top: 1px solid var(--border-strong); }
.flow-line::after {
    content: "";
    position: absolute;
    right: 0;
    top: 0;
    border-block: 4.5px solid transparent;
    border-left: 8px solid var(--border-strong);
}
.flow-rate:first-child .flow-line::before { border-top-color: var(--brand); }
.flow-rate:first-child .flow-line::after { border-left-color: var(--brand); }
.stock-amount {
    position: relative;
    display: grid;
    place-items: center;
    align-content: start;
    gap: 2px;
    min-height: 144px;
    padding-top: 22px;
    overflow: hidden;
    border: 1px solid var(--border-strong);
    border-radius: var(--radius);
    background: linear-gradient(to top, var(--brand-soft) 34%, transparent 34%);
    text-align: center;
}
.stock-amount::after { content: ""; position: absolute; inset: auto 0 34% 0; border-top: 1px dashed color-mix(in srgb, var(--brand) 40%, transparent); }
.stock-amount strong { position: relative; z-index: 1; color: var(--foreground); font: 400 42px/1.1 var(--font-serif); letter-spacing: -.03em; }
.stock-amount span { position: relative; z-index: 1; color: var(--muted-foreground); font: 400 13px var(--font-sans); }

.article-table-wrap { max-width: 100%; overflow-x: auto; margin: 36px 0; }
.article-table { width: 100%; border-collapse: collapse; font: 400 15px/1.5 var(--font-sans); font-variant-numeric: tabular-nums; }
.article-table caption { padding-bottom: 12px; font-size: 13px; text-align: left; }
.article-table th, .article-table td { padding: 13px 12px; border-bottom: 1px solid var(--border); text-align: right; }
.article-table thead { border-top: 1px solid var(--border-strong); font-size: 11px; letter-spacing: .06em; text-transform: uppercase; }
.article-table thead th { font-weight: 500; vertical-align: bottom; }
.article-table tbody th { color: var(--foreground); font-weight: 500; }
.article-table th:first-child { padding-left: 0; text-align: left; }
.article-table td:last-child, .article-table thead th:last-child { padding-right: 0; }
.article-table td:last-child { color: var(--foreground); font-family: var(--font-serif); font-size: 20px; }
.article-table tbody tr:last-child td:last-child { color: var(--brand); }

/* Loops: reinforcing in rust, balancing in sage; the chain closes on itself. */
.feedback-figure { margin: 24px 0; padding: 20px 0 20px 24px; border-left: 2px solid var(--brand); }
.feedback-figure + .feedback-figure { margin-top: -4px; border-left-color: var(--viz-b); }
.article-body .feedback-figure h3 { margin: 0 0 8px; color: var(--muted-foreground); font: 500 13px var(--font-sans); letter-spacing: .01em; }
.causal-chain { margin: 0 0 4px; color: var(--foreground); font: 400 21px/1.65 var(--font-serif); letter-spacing: -.01em; }
.causal-chain span { padding: 0 4px; color: var(--brand); font-family: var(--font-sans); }
.feedback-figure + .feedback-figure .causal-chain span { color: var(--viz-b-strong); }
.causal-chain::after { content: " ↺"; color: var(--subtle-foreground); font-family: var(--font-sans); }
.feedback-figure figcaption { margin-top: 6px; }

/* --------------------------------------------------------------- footer */

.article-sources {
    margin-top: 64px;
    padding-top: 24px;
    border-top: 1px solid var(--border);
    color: var(--muted-foreground);
    font: 400 13px/1.75 var(--font-sans);
}
.article-sources p { margin-bottom: 18px; }
.article-sources a { color: var(--muted-foreground); }
.article-sources a:hover { color: var(--brand); }
.article-sources .article-related { display: inline-block; padding: 4px 0; color: var(--foreground); font: 400 19px var(--font-serif); text-decoration: none; }
.article-sources .article-related:hover { color: var(--brand); }

/* After an end mark or a source card, "Read next" needs no second rule. */
.doc-end + .article-sources { margin-top: 32px; padding-top: 0; border-top: 0; }
.source-card + .article-sources { margin-top: 40px; }

/* The collection pager sits under the text column, not under the rail. */
.article-page:not(.article-page--single) > .collection-pager { margin-left: calc(var(--rail) + var(--rail-gap)); }

/* -------------------------------------------------------- memo & archive
   Shared by High Performance Culture and Autonomous Coding. */

.doc-meta {
    display: grid;
    grid-template-columns: max-content minmax(0, 1fr);
    margin: 22px 0 0;
    border-top: 1px solid var(--border);
    font: 400 14px/1.5 var(--font-sans);
}
.doc-meta dt, .doc-meta dd { margin: 0; padding: 9px 0; border-bottom: 1px solid var(--border); }
.doc-meta dt { padding-right: 28px; color: var(--subtle-foreground); font: 500 10px/2.1 var(--font-mono); letter-spacing: .12em; text-transform: uppercase; }
.doc-meta dd { color: var(--foreground); }

/* A rubber stamp, slightly askew. */
.doc-stamp {
    display: inline-block;
    padding: 3px 9px 2px;
    border: 1.5px solid var(--brand);
    border-radius: 3px;
    color: var(--brand);
    font: 600 11px/1.4 var(--font-mono);
    letter-spacing: .16em;
    text-transform: uppercase;
    transform: rotate(-2deg);
    opacity: .9;
}

/* Redactions read as a solid bar with the word ghosted inside. */
.article-body .redacted {
    display: inline-block;
    padding: 0 .45em;
    border-radius: 1px;
    background: var(--foreground);
    color: color-mix(in srgb, var(--background) 38%, var(--foreground));
    font: 500 .62em/1.75 var(--font-mono);
    letter-spacing: .14em;
    vertical-align: .12em;
    user-select: none;
}

.pull-quote {
    margin: 44px 0;
    padding: 6px 0 6px 28px;
    border-left: 2px solid var(--brand);
    color: var(--foreground);
    font: italic 400 27px/1.4 var(--font-serif);
    letter-spacing: -.018em;
    text-wrap: balance;
}
.pull-quote cite { display: block; margin-top: 12px; color: var(--muted-foreground); font: normal 400 11px var(--font-mono); letter-spacing: .1em; text-transform: uppercase; }

/* Decision ladder: four rungs, one where we should be, one where we drift. */
.article-body .decision-ladder { margin: 28px 0 32px; padding: 0; list-style: none; border-top: 1px solid var(--border); font-family: var(--font-sans); }
.article-body .decision-ladder li { display: flex; justify-content: space-between; align-items: baseline; gap: 16px; margin: 0; padding: 12px 0 12px 22px; border-bottom: 1px solid var(--border); color: var(--muted-foreground); font-size: 15px; position: relative; }
.decision-ladder li::before { content: ""; position: absolute; left: 2px; top: 50%; width: 7px; height: 7px; margin-top: -3.5px; border: 1px solid var(--border-strong); border-radius: 50%; }
.decision-ladder li span { font: 400 11px var(--font-mono); letter-spacing: .06em; text-transform: uppercase; }
.article-body .decision-ladder .is-target { color: var(--foreground); font-weight: 500; background: var(--brand-soft); }
.decision-ladder .is-target::before { border-color: var(--brand); background: var(--brand); }
.decision-ladder .is-target span { color: var(--brand); }
.decision-ladder .is-drift span { color: var(--subtle-foreground); }

/* Good vs. bad DRI behaviors as two marked columns. */
.behavior-compare { display: grid; grid-template-columns: 1fr 1fr; gap: 0 32px; margin: 32px 0; font-family: var(--font-sans); }
.behavior-compare h4 { margin: 0; padding-bottom: 10px; border-bottom: 1px solid var(--border-strong); color: var(--muted-foreground); font: 500 11px var(--font-mono); letter-spacing: .12em; text-transform: uppercase; }
.article-body .behavior-compare ul { margin: 0; padding: 0; list-style: none; }
.article-body .behavior-compare li { position: relative; margin: 0; padding: 10px 0 10px 24px; border-bottom: 1px solid var(--border); font-size: 15px; line-height: 1.45; }
.behavior-compare li::before { position: absolute; left: 0; top: 10px; font: 500 14px/1.45 var(--font-sans); }
.behavior-good li::before { content: "✓"; color: var(--viz-sage-text); }
.behavior-bad li { color: var(--muted-foreground); }
.behavior-bad li::before { content: "✕"; color: var(--brand); font-size: 12px; }

.doc-end {
    display: flex;
    align-items: center;
    gap: 16px;
    margin-top: 56px;
    color: var(--subtle-foreground);
    font: 500 10px var(--font-mono);
    letter-spacing: .16em;
    text-transform: uppercase;
}
.doc-end::before, .doc-end::after { content: ""; flex: 1; border-top: 1px solid var(--border); }

/* Archive clipping: a drop cap and a source card. */
.article-body .has-dropcap::first-letter {
    float: left;
    margin: 6px 10px 0 0;
    color: var(--brand);
    font: 400 68px/.8 var(--font-serif);
}
.source-card {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 20px;
    margin-top: 48px;
    padding: 20px 24px;
    border: 1px solid var(--border);
    border-radius: var(--radius);
    background: var(--surface);
    font-family: var(--font-sans);
}
.source-card p { margin: 0; color: var(--muted-foreground); font-size: 14px; line-height: 1.55; }
.source-card strong { display: block; color: var(--foreground); font: 400 18px var(--font-serif); }
.article-body .source-card a { flex: 0 0 auto; padding: 9px 14px; border: 1px solid var(--border-strong); border-radius: var(--radius-sm); color: var(--foreground); font-size: 14px; text-decoration: none; }
.article-body .source-card a:hover { border-color: var(--brand); color: var(--brand); }

/* ---------------------------------------------------------------- narrow */

@media (max-width: 900px) {
    .collection-subpage .article-page { width: min(100% - 40px, var(--measure)); }
    .article-page > .page-header { margin-left: 0; margin-bottom: 28px; padding-bottom: 24px; }
    .article-layout { display: block; }
    .article-contents {
        position: static;
        max-height: none;
        grid-template-columns: 1fr 1fr;
        gap: 0 20px;
        margin-bottom: 36px;
        padding: 0 0 22px;
        border-bottom: 1px solid var(--border);
    }
    .article-contents::before { grid-column: 1 / -1; }
    .article-contents .toc-sub { display: none; }
    .article-details { display: block; }
    .article-details dl { grid-template-columns: 1fr 1fr; border-left: 0; }
    .article-details dl > div { padding-left: 0; }
    .article-details dl > div:first-child { grid-column: 1 / -1; }
    .article-page:not(.article-page--single) > .collection-pager { margin-left: 0; }
}

@media (max-width: 600px) {
    .article-page .illustrated-header { display: block; }
    .article-page .illustrated-header > .page-art { margin-bottom: 20px; }
    .collection-subpage .article-page--single .page-title { font-size: 29px; }
}

@media (max-width: 480px) {
    .article-body { font-size: 17.5px; line-height: 1.7; }
    .article-body .article-lead { font-size: 20px; }
    .article-body section { margin-top: 52px; }
    .article-body h2 { flex-direction: column; gap: 6px; font-size: 26px; }
    .article-body .section-number { transform: none; }
    .article-body h3 { font-size: 21px; }
    .article-contents { grid-template-columns: 1fr; }
    .article-contents a { font-size: 14px; }
    .standfirst { font-size: 19px; }
    .example-steps > div, .example-pairs > div { grid-template-columns: 1fr; gap: 4px; }
    .reading-list { grid-template-columns: 1fr; }
    .article-practice { margin-inline: -4px; padding: 22px 18px 8px; }
    .stock-flow { grid-template-columns: minmax(0, 1fr) 112px minmax(0, 1fr); gap: 0; }
    .stock-amount { min-height: 124px; padding-top: 18px; }
    .stock-amount strong { font-size: 32px; }
    .flow-rate { font-size: 12px; padding-inline: 6px; }
    .article-table { font-size: 14px; }
    .article-table th, .article-table td { padding-inline: 6px; }
    .causal-chain { font-size: 19px; }
    .pull-quote { padding-left: 18px; font-size: 23px; }
    .behavior-compare { grid-template-columns: 1fr; gap: 28px; }
    .doc-meta { font-size: 14px; }
    .doc-meta dt { padding-right: 18px; }
    .source-card { flex-direction: column; align-items: flex-start; }
}

/* ----------------------------------------------------------------- print */

@media print {
    .article-contents, .article-related, .reading-progress, .site-topbar, .collection-pager { display: none !important; }
    .article-layout { display: block; }
    .article-page > .page-header { margin-left: 0; }
    .collection-subpage .article-page { width: 100%; padding: 0; }
    .article-body { font-size: 11pt; color: #000; }
    .article-body section { break-inside: auto; }
    .article-body h2, .article-body h3 { break-after: avoid; }
    .article-practice, .source-card { background: none; }
    .article-body .redacted { background: #000; color: #666; print-color-adjust: exact; -webkit-print-color-adjust: exact; }
}

@media (prefers-reduced-motion: reduce) {
    .reading-progress { display: none; }
}

/* Memo pages run headings inline rather than in <section>s. */
.article-body > h2 { margin-top: 64px; }
.article-body > h2:first-child { margin-top: 0; }
.article-body .behavior-compare section { margin-top: 0; }