* { box-sizing: border-box; margin: 0; padding: 0; }

:root {
    color-scheme: light;
    --bg-primary: #ffffff;
    --bg-secondary: #f8f9fa;
    --text-primary: #333333;
    --text-heading: #111827;
    --text-secondary: #374151;
    --text-muted: #6b7280;
    --border-color: #e5e7eb;
    --accent: #2e8da8;
    --accent-hover: #236d82;
    --code-bg: #f8f9fa;
    --blockquote-border: #80b6c5;
    --figure-bg: #ffffff;
    --serif: "Iowan Old Style", "Palatino Linotype", "Book Antiqua", Georgia, "Songti SC", serif;
    --sans: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Microsoft YaHei", sans-serif;
    --mono: "SFMono-Regular", Consolas, "Liberation Mono", monospace;
}

html[data-theme="dark"],
body.dark-theme {
    color-scheme: dark;
    --bg-primary: #1a1a1a;
    --bg-secondary: #242424;
    --text-primary: #e5e5e5;
    --text-heading: #f3f4f6;
    --text-secondary: #d1d5db;
    --text-muted: #9ca3af;
    --border-color: #374151;
    --accent: #52adc8;
    --accent-hover: #6bc1dc;
    --code-bg: #242424;
    --blockquote-border: #3d7a8c;
    --figure-bg: #242424;
}

html { background-color: var(--bg-primary); scroll-behavior: smooth; scroll-padding-top: 100px; }
body {
    background: var(--bg-primary);
    color: var(--text-primary);
    font-family: var(--sans);
    font-weight: 450;
    line-height: 1.7;
    min-height: 100vh;
    -webkit-font-smoothing: antialiased;
}
html.theme-booting body,
html.theme-booting .site-header { transition: none !important; }
[hidden], .is-hidden { display: none !important; }
.sr-only { position: absolute; width: 1px; height: 1px; padding: 0; margin: -1px; overflow: hidden; clip: rect(0, 0, 0, 0); white-space: nowrap; border: 0; }
::selection { background: var(--accent); color: var(--bg-primary); }
a { color: var(--accent); text-decoration: none; }
a:hover { color: var(--accent-hover); }
button { font: inherit; }
a, button { -webkit-tap-highlight-color: transparent; }
a:focus-visible, button:focus-visible { outline: 2px solid var(--accent); outline-offset: 5px; }
.container { width: min(100%, 1080px); margin: 0 auto; padding: 0 40px; }
.skip-link { position: fixed; top: -100px; left: 20px; padding: 12px 20px; z-index: 100; background: var(--bg-primary); border: 1px solid var(--accent); }
.skip-link:focus { top: 12px; }

/* A quiet, shared navigation for the notebook and its pages. */
.site-header {
    position: sticky;
    top: 0;
    z-index: 20;
    background: color-mix(in srgb, var(--bg-primary) 94%, transparent);
    backdrop-filter: blur(12px);
    border-bottom: 1px solid var(--border-color);
}
.nav { display: flex; align-items: center; justify-content: space-between; min-height: 72px; gap: 24px; }
.brand { display: inline-flex; align-items: center; gap: 11px; color: var(--text-heading); font-size: 14px; font-weight: 650; letter-spacing: -.025em; white-space: nowrap; }
.brand-mark { font-family: var(--serif); font-size: 29px; font-style: italic; font-weight: 650; line-height: 1; color: var(--accent); }
.nav-right { display: flex; align-items: center; gap: 24px; }
.nav-right > a { color: var(--text-muted); font-size: 13px; font-weight: 550; }
.nav-right > a:hover, .nav-right > a.active { color: var(--text-primary); }
.nav-right > a.active { text-decoration: underline; text-decoration-color: var(--accent); text-underline-offset: 8px; }
.nav-divider { width: 1px; height: 17px; background: var(--border-color); }
.theme-toggle { display: grid; place-items: center; width: 36px; height: 36px; background: none; border: 0; border-radius: 50%; color: var(--text-secondary); cursor: pointer; }
.theme-toggle:hover, .theme-toggle.is-active { background: var(--bg-secondary); color: var(--accent); }
.lang-toggle { background: transparent; border: 1px solid var(--border-color); border-radius: 5px; cursor: pointer; display: grid; grid-template-columns: 1fr 1fr; width: 66px; height: 32px; padding: 2px; position: relative; }
.lang-toggle::before { background: var(--bg-secondary); border-radius: 3px; content: ""; position: absolute; inset: 2px auto 2px 2px; width: calc(50% - 2px); transition: transform .18s; }
body[data-lang="zh"] .lang-toggle::before { transform: translateX(100%); }
.lang-toggle__option { display: grid; place-items: center; position: relative; font: 600 11px var(--mono); color: var(--text-muted); }
.lang-toggle__option[data-opt="en"], body[data-lang="zh"] .lang-toggle__option[data-opt="zh"] { color: var(--text-heading); }
body[data-lang="zh"] .lang-toggle__option[data-opt="en"] { color: var(--text-muted); }

/* A compact introduction keeps the writing within reach. */
.notebook-hero { display: grid; grid-template-columns: minmax(0, 1fr) 205px; align-items: end; gap: 42px; padding: 46px 0 38px; }
.eyebrow { display: flex; align-items: center; gap: 10px; color: var(--text-muted); font: 600 10px/1.5 var(--mono); letter-spacing: .12em; text-transform: uppercase; }
.status-dot { width: 6px; height: 6px; border-radius: 50%; background: var(--accent); }
.notebook-hero h1 { max-width: 700px; margin-top: 17px; color: var(--text-heading); font: 650 clamp(34px, 4vw, 48px)/1.14 var(--serif); letter-spacing: -.04em; }
body[data-lang="zh"] .notebook-hero h1 { letter-spacing: .01em; line-height: 1.25; }
.hero-intro { max-width: 620px; margin-top: 13px; color: var(--text-secondary); font-size: 15px; font-weight: 500; line-height: 1.75; }
.hero-note { border-left: 1px solid var(--border-color); padding: 3px 0 3px 20px; }
.hero-note p { color: var(--text-secondary); font-size: 13px; font-weight: 500; line-height: 1.7; }
.hero-note a { display: inline-block; margin-top: 8px; font-size: 12px; font-weight: 600; }

/* Half-year editions keep old links and original publication dates intact. */
.archive { border-top: 1px solid var(--border-color); }
.archive-toolbar { display: flex; align-items: center; justify-content: space-between; gap: 20px; padding: 17px 0; border-bottom: 1px solid var(--border-color); }
.year-filters { display: flex; align-items: center; gap: 5px; }
.year-filters a { color: var(--text-muted); padding: 5px 10px; border-radius: 4px; font: 600 12px/1.8 var(--mono); }
.year-filters a:hover { color: var(--accent); background: var(--bg-secondary); }
.year-filters a[aria-current="true"] { background: var(--text-heading); color: var(--bg-primary); }
.year-section { display: grid; grid-template-columns: 145px minmax(0, 1fr); gap: 34px; padding: 29px 0; border-bottom: 1px solid var(--border-color); }
.year-heading h3 { display: flex; align-items: center; gap: 10px; color: var(--text-heading); font: 650 34px/1.15 var(--serif); letter-spacing: -.05em; }
.year-dot { width: 5px; height: 5px; border-radius: 50%; background: var(--accent); }
.year-heading p { margin-top: 7px; color: var(--text-muted); font-size: 12px; font-weight: 550; }
.year-content { min-width: 0; }
.feature-post { overflow: hidden; border: 1px solid var(--border-color); border-radius: 6px; background: var(--bg-secondary); }
.article-card-link { display: block; min-width: 0; color: inherit; cursor: pointer; text-decoration: none; }
.article-card-link:hover { color: inherit; text-decoration: none; }
.article-card-link:focus-visible { outline: 2px solid var(--accent); outline-offset: 4px; }
.feature-post .article-card-link:focus-visible { outline-offset: -4px; }
.feature-post .article-card-link { display: grid; grid-template-columns: minmax(0, 1fr) 255px; gap: 28px; padding: 24px; }
.feature-post h4 { max-width: 610px; color: var(--text-heading); font: 650 31px/1.18 var(--serif); letter-spacing: -.03em; }
.feature-post h4, .post-card h4 { color: var(--text-heading); }
.feature-post .post-excerpt { max-width: 610px; }
.feature-figure { display: grid; place-items: center; min-height: 192px; padding: 12px; border: 1px solid var(--border-color); border-radius: 4px; background: var(--figure-bg); }
.feature-figure img { display: block; width: 100%; max-height: 205px; object-fit: contain; }
.post-card .article-card-link { padding: 27px 0; }
.feature-post + .post-card, .post-card + .post-card { border-top: 1px solid var(--border-color); }
.post-card__banner { display: block; width: 100%; height: auto; margin-bottom: 18px; border: 1px solid var(--border-color); border-radius: 6px; }
.post-card[data-secret="true"] { display: none; }
body.show-secret-posts .post-card[data-secret="true"] { display: block; }
.post-kicker { display: flex; align-items: center; gap: 10px; color: var(--text-muted); font: 600 11px/1.6 var(--mono); letter-spacing: .04em; text-transform: uppercase; margin-bottom: 8px; }
.post-card h4 { max-width: 660px; color: var(--text-heading); font: 650 25px/1.28 var(--serif); letter-spacing: -.025em; }
.post-excerpt { max-width: 680px; color: var(--text-secondary); font-size: 15px; font-weight: 500; line-height: 1.75; margin-top: 10px; }
.read-article { display: inline-block; margin-top: 13px; color: var(--accent); font-size: 13px; font-weight: 650; }
.secret-badge { border: 1px solid var(--border-color); border-radius: 3px; color: var(--accent); font: 600 10px var(--mono); padding: 3px 5px; }
.feynman-card-link { display: grid; grid-template-columns: 78px minmax(0, 1fr); gap: 18px; align-items: start; }
.feynman-mark { display: block; flex: 0 0 auto; }
.feynman-mark--card { width: 78px; height: 78px; margin-top: 2px; }

@media (hover: hover) {
    .feature-post, .post-card { transition: transform .18s ease, border-color .18s ease, box-shadow .18s ease; }
    .article-card-link { transition: background-color .18s ease; }
    .feature-post:has(.article-card-link:hover), .post-card:has(.article-card-link:hover) {
        border-color: color-mix(in srgb, var(--accent) 42%, var(--border-color));
        transform: translateY(-2px);
    }
    .feature-post:has(.article-card-link:hover) { box-shadow: 0 9px 22px color-mix(in srgb, var(--text-heading) 9%, transparent); }
    .feature-post .article-card-link:hover, .post-card .article-card-link:hover { background: color-mix(in srgb, var(--accent) 5%, transparent); }
}
.year-section--upcoming { padding-top: 20px; padding-bottom: 20px; }
.year-section--upcoming .year-heading h3 { font-size: 27px; }
.year-section--upcoming .year-empty { display: flex; align-items: center; gap: 13px; min-height: 44px; color: var(--text-muted); }
.year-section--upcoming .empty-mark { flex-shrink: 0; white-space: nowrap; font: 16px var(--mono); color: var(--accent); opacity: .75; }
.year-section--upcoming .year-empty p { font-size: 14px; font-weight: 500; }

.private-note { display: flex; align-items: center; justify-content: space-between; gap: 20px; margin: 26px 0 52px; padding: 15px 18px; border: 1px solid var(--border-color); border-radius: 4px; background: var(--bg-secondary); }
.private-note > div { display: flex; align-items: center; gap: 12px; }
.private-icon { font-size: 23px; color: var(--text-muted); }
.secret-hint, .unlocked-hint { font-size: 12px; font-weight: 500; color: var(--text-muted); }
.unlocked-hint { display: none; }
body.show-secret-posts .unlocked-hint { display: block; }
.unlock-btn { background: transparent; border: 1px solid var(--border-color); border-radius: 4px; color: var(--text-secondary); cursor: pointer; white-space: nowrap; font-size: 12px; font-weight: 600; padding: 6px 14px; }
.unlock-btn:hover, .unlock-btn.is-active { color: var(--accent); border-color: var(--accent); }
.footer { display: flex; justify-content: space-between; align-items: center; gap: 20px; border-top: 1px solid var(--border-color); padding-top: 22px; padding-bottom: 26px; font-size: 11px; font-weight: 500; color: var(--text-muted); }
.footer > p:nth-child(2) { font-family: var(--serif); font-style: italic; font-size: 13px; }
.footer a { color: var(--text-muted); }

/* Reading pages share the palette, with a narrower and more generous measure. */
body:not(.blog-index) main.container { max-width: 880px; }
.post { margin: 42px 0 60px; }
.back-link { display: inline-block; font-size: 13px; font-weight: 600; color: var(--text-muted); margin-bottom: 29px; }
.post-header { border-bottom: 1px solid var(--border-color); margin-bottom: 35px; padding-bottom: 30px; }
.post-header h1 { color: var(--text-heading); font: 650 clamp(30px, 4vw, 44px)/1.18 var(--serif); letter-spacing: -.03em; margin-bottom: 18px; }
.feynman-title-row { display: flex; align-items: flex-start; gap: 18px; }
.feynman-title-row h1 { min-width: 0; }
.feynman-mark--header { width: 60px; height: 60px; margin-top: 1px; }
.post-header .meta { color: var(--text-muted); font: 600 12px var(--mono); margin-bottom: 18px; }
.post-header .summary { color: var(--text-secondary); font-size: 15px; font-weight: 500; line-height: 1.85; }
.markdown-body { font-size: 16px; font-weight: 450; line-height: 1.9; overflow-wrap: break-word; }
.markdown-body > *, .markdown-body [data-lang] > * { margin-bottom: 1rem; }
.markdown-body h1, .markdown-body h2, .markdown-body h3, .markdown-body h4, .markdown-body h5, .markdown-body h6 { color: var(--text-heading); font-weight: 650; line-height: 1.35; margin-top: 2rem; margin-bottom: 1rem; }
.markdown-body h1 { font: 650 32px var(--serif); }
.markdown-body h2 { font: 650 27px/1.4 var(--serif); }
.markdown-body h3 { font-size: 18px; }
.markdown-body p, .markdown-body li, .markdown-body blockquote { color: var(--text-secondary); font-weight: 450; }
.markdown-body a { font-weight: 550; text-decoration: underline; text-underline-offset: 3px; }
.markdown-body ul, .markdown-body ol { padding-left: 1.4rem; }
.markdown-body li { margin-bottom: .4rem; }
.markdown-body pre { background: var(--code-bg); border: 1px solid var(--border-color); border-radius: 5px; overflow-x: auto; padding: 20px; }
.markdown-body code { background: var(--code-bg); border-radius: 3px; font-family: var(--mono); font-size: .85em; padding: .1em .3em; }
.markdown-body pre code { background: transparent; padding: 0; font-size: 12px; line-height: 1.65; tab-size: 4; }
.markdown-body pre code.hljs { background: transparent; display: block; padding: 0; }
.markdown-body blockquote { border-left: 2px solid var(--blockquote-border); padding: .3rem 0 .3rem 1.3rem; margin: 1.5rem 0; }
.markdown-body img { display: block; max-width: 100%; height: auto; margin: 1.8rem auto; border-radius: 4px; }
.markdown-body hr { border: 0; border-top: 1px solid var(--border-color); margin: 2rem 0; }
.markdown-body table { display: block; overflow-x: auto; max-width: 100%; border-collapse: collapse; }
.markdown-body th, .markdown-body td { border: 1px solid var(--border-color); padding: 10px 14px; text-align: left; }
.markdown-body th { font-weight: 650; }
.markdown-body td { font-weight: 450; }
.secret-gate { margin: 42px 0; padding: 28px; border: 1px solid var(--border-color); border-radius: 5px; background: var(--bg-secondary); }
.secret-gate h2 { color: var(--text-heading); font: 650 28px var(--serif); margin-bottom: 12px; }
.secret-gate p { color: var(--text-secondary); font-weight: 500; margin-bottom: 20px; }
body[data-post-secret="true"] #post-content { display: none; }
body[data-post-secret="true"] #secret-locked-message { display: block; }
body[data-post-secret="true"].secret-unlocked #post-content { display: block; }
body[data-post-secret="true"].secret-unlocked #secret-locked-message { display: none; }

/* Series: a shelf on the index, one landing page per series, and a banner plus pager on each part. */
.series-badge { border: 1px solid color-mix(in srgb, var(--accent) 45%, var(--border-color)); border-radius: 3px; color: var(--accent); font: 600 10px var(--mono); padding: 3px 5px; white-space: nowrap; }
.post-kicker:has(.series-badge) { flex-wrap: wrap; row-gap: 6px; }
.post-kicker:has(.series-badge) > span:first-child { white-space: nowrap; }
.series-shelf { padding-bottom: 30px; }
.series-shelf__list { display: grid; gap: 18px; padding-top: 24px; }
.series-card { position: relative; border: 1px solid var(--border-color); border-radius: 6px; background: var(--bg-secondary); box-shadow: 5px 5px 0 -1px var(--bg-primary), 5px 5px 0 0 var(--border-color); }
.series-card .article-card-link { display: grid; grid-template-columns: minmax(0, 1fr) auto; align-items: end; gap: 24px; padding: 22px 24px; border-radius: 6px; }
.series-card h3 { max-width: 640px; color: var(--text-heading); font: 650 27px/1.22 var(--serif); letter-spacing: -.025em; }
.series-card__latest { margin-top: 12px; color: var(--text-muted); font-size: 13px; font-weight: 550; }
.series-card__latest strong { color: var(--text-secondary); font-weight: 650; }
.series-card__count { text-align: right; color: var(--text-muted); font: 600 11px/1.5 var(--mono); letter-spacing: .04em; text-transform: uppercase; white-space: nowrap; }
.series-card__count b { display: block; color: var(--accent); font: 650 42px/1 var(--serif); letter-spacing: -.04em; }
@media (hover: hover) {
    .series-card { transition: transform .18s ease, border-color .18s ease; }
    .series-card:has(.article-card-link:hover) { border-color: color-mix(in srgb, var(--accent) 42%, var(--border-color)); transform: translateY(-2px); }
    .series-card .article-card-link:hover { background: color-mix(in srgb, var(--accent) 5%, transparent); }
}

.series-banner { display: flex; flex-wrap: wrap; align-items: center; gap: 6px 12px; margin-bottom: 16px; color: var(--text-muted); font: 600 11px/1.6 var(--mono); letter-spacing: .04em; text-transform: uppercase; }
.series-banner__label { display: inline-flex; align-items: center; gap: 8px; }
.series-banner__label::before { content: ""; width: 6px; height: 6px; border-radius: 50%; background: var(--accent); }
.series-banner__name { color: var(--accent); }
.series-banner__part { border: 1px solid var(--border-color); border-radius: 3px; color: var(--text-secondary); padding: 1px 6px; }

.series-pager { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 14px; margin-top: 48px; padding-top: 28px; border-top: 1px solid var(--border-color); }
.series-pager__item { display: flex; flex-direction: column; gap: 6px; min-width: 0; padding: 16px 18px; border: 1px solid var(--border-color); border-radius: 5px; color: inherit; }
.series-pager__item:hover { color: inherit; border-color: color-mix(in srgb, var(--accent) 42%, var(--border-color)); }
.series-pager__item--prev { grid-column: 1; }
.series-pager__item--next { grid-column: 2; text-align: right; }
.series-pager__item.is-upcoming { border-style: dashed; background: var(--bg-secondary); }
.series-pager__dir { color: var(--accent); font: 600 11px/1.6 var(--mono); letter-spacing: .04em; text-transform: uppercase; }
.series-pager__item.is-upcoming .series-pager__dir { color: var(--text-muted); }
.series-pager__title { color: var(--text-heading); font: 650 17px/1.4 var(--serif); }
.series-pager__item.is-upcoming .series-pager__title { color: var(--text-muted); font: 500 14px/1.6 var(--sans); }
.series-pager__all { grid-column: 1 / -1; justify-self: center; margin-top: 6px; font-size: 13px; font-weight: 600; }

.series-header .eyebrow { margin-bottom: 16px; }
.series-facts { display: flex; flex-wrap: wrap; gap: 10px 34px; margin-top: 22px; }
.series-facts dt { color: var(--text-muted); font: 600 10px/1.6 var(--mono); letter-spacing: .12em; text-transform: uppercase; }
.series-facts dd { color: var(--text-heading); font-size: 14px; font-weight: 600; }
.series-parts-title { margin-bottom: 6px; }
.series-parts { list-style: none; }
.series-part { border-bottom: 1px solid var(--border-color); }
.series-part__link { display: grid; grid-template-columns: 64px minmax(0, 1fr); gap: 18px; padding: 24px 0; color: inherit; }
a.series-part__link:hover { color: inherit; background: color-mix(in srgb, var(--accent) 5%, transparent); }
.series-part__num { color: var(--accent); font: 650 34px/1.05 var(--serif); letter-spacing: -.04em; font-variant-numeric: tabular-nums; }
.series-part__title { display: block; color: var(--text-heading); font: 650 23px/1.3 var(--serif); letter-spacing: -.02em; }
.series-part__body .post-excerpt { display: block; margin-top: 8px; }
.series-part[data-part-status="upcoming"] .series-part__num { color: var(--text-muted); opacity: .6; }
.series-part[data-part-status="upcoming"] .series-part__title { color: var(--text-muted); }
.series-empty { display: flex; align-items: center; gap: 13px; padding: 24px 0; border-bottom: 1px solid var(--border-color); color: var(--text-muted); }
.series-empty .empty-mark { flex-shrink: 0; white-space: nowrap; font: 16px var(--mono); color: var(--accent); opacity: .75; }
.series-empty p { font-size: 14px; font-weight: 500; }

@media (min-width: 1500px) {
    .notebook-hero { padding-top: 58px; padding-bottom: 46px; }
}
@media (max-width: 900px) {
    .container { padding-left: 28px; padding-right: 28px; }
    .notebook-hero { grid-template-columns: 1fr; gap: 20px; padding: 38px 0 32px; }
    .notebook-hero h1 { font-size: clamp(34px, 6.5vw, 45px); }
    .hero-note { border: 0; padding: 0; }
    .year-section { grid-template-columns: 120px minmax(0, 1fr); gap: 26px; }
    .feature-post .article-card-link { grid-template-columns: minmax(0, 1fr) 210px; gap: 22px; }
    .nav-right { gap: 20px; }
}
@media (max-width: 600px) {
    html { scroll-padding-top: 128px; }
    .container { padding-left: 22px; padding-right: 22px; }
    .nav { min-height: 102px; flex-wrap: wrap; gap: 8px; padding-top: 12px; padding-bottom: 10px; }
    .brand { width: 100%; font-size: 13px; gap: 10px; }
    .brand-mark { font-size: 28px; }
    .nav-right { width: 100%; justify-content: space-between; gap: 12px; }
    .nav-right > a { font-size: 12px; }
    .nav-divider { margin-left: auto; }
    .notebook-hero { padding: 31px 0 27px; gap: 16px; }
    .notebook-hero h1 { margin-top: 13px; font-size: clamp(30px, 8vw, 38px); }
    .hero-intro { margin-top: 10px; font-size: 14px; }
    .hero-note p { font-size: 12px; }
    .archive-toolbar { flex-wrap: wrap; align-items: flex-start; gap: 12px; padding: 17px 0; }
    .eyebrow { font-size: 10px; }
    .year-filters { width: 100%; flex-wrap: wrap; gap: 4px; }
    .year-filters a { font-size: 12px; padding: 5px 8px; white-space: nowrap; }
    .year-section { grid-template-columns: 1fr; gap: 17px; padding-top: 24px; padding-bottom: 24px; }
    .year-heading { display: flex; align-items: baseline; gap: 18px; }
    .year-heading h3 { font-size: 30px; }
    .year-heading p { margin-top: 0; }
    .feature-post .article-card-link { display: block; padding: 19px; }
    .feature-figure { display: none; }
    .feature-post h4 { font-size: 27px; }
    .post-card .article-card-link { padding: 22px 0; }
    .post-card h4 { font-size: 23px; }
    .post-kicker { font-size: 11px; }
    .post-excerpt { font-size: 14px; }
    .read-article { font-size: 13px; }
    .year-section--upcoming .year-heading h3 { font-size: 25px; }
    .year-section--upcoming .year-empty p { font-size: 14px; }
    .private-note { padding: 14px; margin-bottom: 38px; gap: 12px; }
    .private-icon { display: none; }
    .private-note > div { min-width: 0; }
    .secret-hint, .unlocked-hint { font-size: 11px; }
    .footer { flex-wrap: wrap; column-gap: 10px; row-gap: 10px; }
    .footer > p:nth-child(2) { order: 3; width: 100%; }
    .post { margin-top: 30px; }
    .back-link { margin-bottom: 26px; }
    .post-header h1 { font-size: 30px; }
    .feynman-title-row { gap: 13px; }
    .feynman-mark--header { width: 52px; height: 52px; }
    .feynman-card-link { grid-template-columns: 62px minmax(0, 1fr); gap: 14px; }
    .feynman-mark--card { width: 62px; height: 62px; }
    .markdown-body { font-size: 15px; }
    .markdown-body pre { padding: 14px; }
    .series-card .article-card-link { grid-template-columns: 1fr; gap: 14px; padding: 19px; }
    .series-card h3 { font-size: 24px; }
    .series-card__count { text-align: left; }
    .series-card__count b { display: inline; margin-right: 8px; font-size: 30px; }
    .series-pager { grid-template-columns: 1fr; }
    .series-pager__item--prev, .series-pager__item--next { grid-column: 1; }
    .series-pager__item--next { text-align: left; }
    .series-part__link { grid-template-columns: 44px minmax(0, 1fr); gap: 12px; padding: 20px 0; }
    .series-part__num { font-size: 27px; }
    .series-part__title { font-size: 20px; }
}
@media (prefers-reduced-motion: reduce) {
    html { scroll-behavior: auto; }
    *, *::before, *::after { transition: none !important; }
    .feature-post:has(.article-card-link:hover), .post-card:has(.article-card-link:hover) { transform: none; }
}