body.notes {
 --bg-base:        #ffffff;
 --bg-elevated:    #ffffff;
 --bg-soft:        #f6f6f4;
 --bg-hover:       #ececea;

 --text-primary:   #18181a;
 --text-body:      #2b2b29;
 --text-muted:     #68655d;
 --text-faint:     #9a9689;

 --accent:         #9c2b2b;
 --accent-bright:  #c23f3f;
 --accent-soft:    rgba(156, 43, 43, 0.07);
 --accent-line:    rgba(156, 43, 43, 0.28);

 --rule:           #e3e2dd;
 --rule-strong:    #cac9c1;

 --status-published: #3f7d4f;
 --status-review:    #b5792a;
 --status-submitted: #857f6e;

 --shadow-soft:    0 1px 0 rgba(20,18,12,0.04), 0 8px 20px -14px rgba(20,18,12,0.22);
 --shadow-lift:    0 16px 36px -18px rgba(20,18,12,0.28);

 --font-display:   'Source Serif 4', Georgia, 'Iowan Old Style', serif;

 background-image: none;
 background-color: var(--bg-base);
}

body.notes .grain { opacity: 0.025; }

body.notes .site-header { border-bottom-color: var(--rule); }
body.notes .nav-links a.active { color: var(--accent); }

/* =========================================================
  Notes index
  ========================================================= */

body.notes .blog-hero { text-align: left; margin: 3rem auto 0; max-width: 780px; }
.blog-hero-eyebrow {
 display: block; font-family: var(--font-mono); font-size: 0.7rem; letter-spacing: 0.12em;
 text-transform: uppercase; color: var(--accent); margin-bottom: 0.6rem;
}
body.notes .blog-hero h1 { font-size: 2.3rem; margin-bottom: 0.55rem; letter-spacing: -0.015em; }
body.notes .blog-hero p { color: var(--text-muted); font-size: 1.02rem; max-width: 54ch; font-family: var(--font-display); }

/* "Serendipitous discovery" — a quiet text control, not a game-show
   button. It should read as a feature of the archive, not a CTA
   competing with Read/Explore actions elsewhere on the page. */
.surprise-btn {
 display: inline-flex; align-items: center; gap: 0.45rem; white-space: nowrap;
 font-family: var(--font-mono); font-size: 0.8rem; color: var(--text-muted);
 background: none; border: none; padding: 0.3rem 0; cursor: pointer;
}
.surprise-btn:hover, .surprise-btn:focus-visible { color: var(--accent); }
.surprise-btn i { font-size: 0.78rem; }

.blog-hero-bar {
 max-width: 780px; margin: 0 auto 2.3rem; padding-bottom: 1.3rem; border-bottom: 1px solid var(--rule);
 display: flex; align-items: center; justify-content: space-between; gap: 1rem; flex-wrap: wrap;
}
.blog-stats {
 font-family: var(--font-mono); font-size: 0.78rem; color: var(--text-muted);
}
.blog-stats strong { color: var(--text-primary); font-weight: 600; }
.blog-stats-sep { margin: 0 0.5rem; color: var(--text-faint); }

.notes-filter { max-width: 780px; margin: 0 auto 1.6rem; display: flex; flex-direction: column; gap: 0.85rem; }

.notes-search {
 display: flex; align-items: center; gap: 0.55rem;
 border: 1px solid var(--rule-strong); border-radius: 99px;
 padding: 0.5rem 0.6rem 0.5rem 0.9rem; background: var(--bg-elevated);
 transition: border-color 0.15s ease;
}
.notes-search:focus-within { border-color: var(--accent-line); }
.notes-search i { color: var(--text-faint); font-size: 0.82rem; }
.notes-search input {
 flex: 1 1 auto; border: none; background: none; outline: none;
 font-family: var(--font-body); font-size: 0.88rem; color: var(--text-primary);
}
.notes-search input::placeholder { color: var(--text-faint); }
.notes-search-kbd {
 font-family: var(--font-mono); font-size: 0.68rem; color: var(--text-faint);
 border: 1px solid var(--rule-strong); border-radius: 4px; padding: 0.1rem 0.4rem;
 background: var(--bg-soft);
}

.notes-tag-filter { display: flex; flex-wrap: wrap; gap: 0.45rem; }
.filter-pill {
 font-family: var(--font-mono); font-size: 0.72rem; letter-spacing: 0.02em;
 color: var(--text-muted); background: var(--bg-elevated); border: 1px solid var(--rule-strong);
 padding: 0.28rem 0.7rem; border-radius: 99px; cursor: pointer; transition: all 0.15s ease;
}
.filter-pill:hover { border-color: var(--accent-line); color: var(--text-primary); }
.filter-pill.is-active { background: var(--accent); border-color: var(--accent); color: var(--bg-elevated); }

.notes-empty {
 max-width: 780px; margin: 0 auto 1.6rem; font-size: 0.92rem; color: var(--text-muted);
 text-align: center; padding: 1.4rem 1rem;
}
.notes-empty button {
 font: inherit; color: var(--accent); background: none; border: none; padding: 0;
 text-decoration: underline; text-underline-offset: 2px; cursor: pointer;
}

/* Topic-tag pills — used inside each individual post's abstract box
   (.note-abstract-tags) and, with the -clickable modifier, as the
   clickable shortcuts into the Archive's tag filter from post-list-tag
   pills on the index (see notes.js). Kept as pills deliberately: these
   are genuinely interactive controls, not just labels. */
.tag-pill {
 font-family: var(--font-mono); font-size: 0.66rem; letter-spacing: 0.03em;
 color: var(--text-muted); border: 1px solid var(--rule-strong);
 padding: 0.14rem 0.5rem; border-radius: 99px;
}
.tag-pill-clickable { cursor: pointer; transition: all 0.15s ease; }
.tag-pill-clickable:hover { border-color: var(--accent-line); color: var(--accent); }

/* =========================================================
   Single note — paper header, abstract, TOC
   ========================================================= */

.post-back {
  display: inline-flex; align-items: center; gap: 0.4rem;
  font-family: var(--font-mono); font-size: 0.78rem; color: var(--text-muted);
  margin: 2rem auto 1.8rem; max-width: 640px; padding-left: 0.5rem;
}
.post-back:hover { color: var(--accent); }
.page-inner .post-back { display: flex; }

.post-article { max-width: 640px; margin: 0 auto; }

.note-kicker {
  font-family: var(--font-mono); font-size: 0.7rem; letter-spacing: 0.14em; text-transform: uppercase;
  color: var(--accent); margin-bottom: 0.7rem; display: block;
}

.post-article-header { margin-bottom: 0; padding-bottom: 0; border-bottom: none; }
.post-article-header h1 { font-size: 1.95rem; margin: 0 0 0.7rem; letter-spacing: -0.015em; line-height: 1.2; }

.note-byline {
  display: flex; flex-wrap: wrap; align-items: center; gap: 0.5rem;
  font-family: var(--font-mono); font-size: 0.78rem; color: var(--text-muted);
  margin-bottom: 1.4rem;
}
.note-byline .sep { color: var(--rule-strong); }

.series-badge {
  display: inline-flex; align-items: center; font-family: var(--font-mono); font-size: 0.7rem;
  color: var(--accent); background: var(--accent-soft); border: 1px solid var(--accent-line);
  border-radius: 99px; padding: 0.14rem 0.55rem;
}

.note-abstract {
  background: var(--bg-elevated);
  border: 1px solid var(--rule);
  border-radius: var(--radius);
  padding: 1.2rem 1.35rem;
  margin-bottom: 1.6rem;
  box-shadow: var(--shadow-soft);
}
.note-abstract-label {
  font-family: var(--font-mono); font-size: 0.68rem; letter-spacing: 0.12em; text-transform: uppercase;
  color: var(--accent); display: block; margin-bottom: 0.55rem;
}
.note-abstract p { margin: 0; font-family: var(--font-display); font-size: 1rem; line-height: 1.65; color: var(--text-body); }
.note-abstract-tags { display: flex; flex-wrap: wrap; gap: 0.4rem; margin-top: 0.9rem; }

.note-toc {
  background: var(--bg-soft);
  border: 1px solid var(--rule);
  border-radius: var(--radius);
  margin-bottom: 2rem;
  overflow: hidden;
}
.note-toc summary {
  cursor: pointer;
  list-style: none;
  padding: 0.75rem 1.1rem;
  font-family: var(--font-mono);
  font-size: 0.76rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--text-muted);
  display: flex;
  align-items: center;
  justify-content: space-between;
}
.note-toc summary::-webkit-details-marker { display: none; }
.note-toc summary::after { content: "+"; font-family: var(--font-mono); color: var(--accent); font-size: 0.95rem; }
.note-toc[open] summary::after { content: "\2212"; }
.note-toc summary:hover { color: var(--text-primary); }
.note-toc-list { list-style: none; margin: 0; padding: 0 1.1rem 1rem; display: flex; flex-direction: column; gap: 0.4rem; }
.note-toc-list a { font-size: 0.88rem; color: var(--text-body); background: none; }
.note-toc-list a:hover { color: var(--accent); }
.note-toc-list .toc-h3 { padding-left: 1.1rem; font-size: 0.84rem; color: var(--text-muted); }

.post-article-body { font-family: var(--font-display); font-size: 1.03rem; line-height: 1.78; color: var(--text-body); }
.post-article-body p { margin: 0 0 1.2rem; }
.post-article-body h2 { font-size: 1.32rem; margin: 2.2rem 0 1rem; scroll-margin-top: 90px; }
.post-article-body h3 { font-size: 1.1rem; margin: 1.8rem 0 0.8rem; scroll-margin-top: 90px; }
.post-article-body ul, .post-article-body ol { margin: 0 0 1.2rem; padding-left: 1.4rem; color: var(--text-body); }
.post-article-body li { margin-bottom: 0.4rem; }
.post-article-body img { max-width: 100%; border-radius: var(--radius); border: 1px solid var(--rule); margin: 1.5rem 0; display: block; }
.post-article-body figcaption { font-family: var(--font-body); font-size: 0.8rem; color: var(--text-muted); text-align: center; margin-top: 0.75rem; margin-bottom: 1.5rem; }
.post-article-body blockquote { margin: 1.5rem 0; padding: 0.2rem 1.2rem; border-left: 2px solid var(--accent); color: var(--text-muted); font-style: italic; }
.post-article-body code { font-family: var(--font-mono); font-size: 0.87em; background: var(--bg-soft); border: 1px solid var(--rule); padding: 0.1em 0.4em; border-radius: 3px; color: var(--accent); }
.post-article-body pre { background: var(--bg-elevated); border: 1px solid var(--rule); border-radius: var(--radius); padding: 1rem 1.2rem; overflow-x: auto; margin: 0 0 1.2rem; }
.post-article-body pre code { background: none; border: none; padding: 0; color: var(--text-body); font-family: var(--font-mono); }

.thm-box {
 background: var(--bg-elevated); border: 1px solid var(--rule); border-left: 3px solid var(--accent);
 border-radius: var(--radius); padding: 1rem 1.25rem; margin: 1.6rem 0; box-shadow: var(--shadow-soft);
}
.thm-label {
 font-family: var(--font-mono); font-size: 0.68rem; letter-spacing: 0.1em; text-transform: uppercase;
 color: var(--accent); display: block; margin-bottom: 0.55rem;
}
.thm-box p { margin: 0; font-size: 0.98rem; line-height: 1.7; }
.thm-box p + p { margin-top: 0.8rem; }
.thm-box a { color: var(--accent); }

.post-attachments { margin-top: 2.4rem; padding-top: 1.5rem; border-top: 1px solid var(--rule); }
.post-attachments h3 { font-family: var(--font-mono); font-size: 0.72rem; letter-spacing: 0.1em; text-transform: uppercase; color: var(--text-muted); margin-bottom: 0.9rem; }
.attachment-link {
  display: inline-flex; align-items: center; gap: 0.5rem;
  font-family: var(--font-mono); font-size: 0.83rem; color: var(--text-primary);
  background: var(--bg-elevated); border: 1px solid var(--rule-strong);
  padding: 0.48rem 0.85rem; border-radius: var(--radius); margin: 0 0.5rem 0.5rem 0;
  background-image: none;
}
.attachment-link:hover { border-color: var(--accent); color: var(--accent); }

/* Figures: narrower than the full text column so plots and diagrams
   read as figures rather than full-bleed images, and stay centered. */
.post-figure { margin: 1.8rem 0; }
.post-article-body .post-figure img {
  max-width: 580px;
  width: 100%;
  margin: 0 auto;
}

/* Ensures videos fit their containers and match image styling */
.post-article-body video {
  max-width: 100%;
  height: auto;
  display: block;
  margin: 0 auto;
  border-radius: var(--radius);
  border: 1px solid var(--rule);
}
/* =========================================================
   Post heading — image + title/tagline, for posts that have
   a hero image (currently just SQEP). A little bigger than
   the original 140px art column, not dramatically so.
   ========================================================= */

.featured-badge {
 display: inline-flex;
 align-items: center;
 gap: 0.5rem;
 font-family: var(--font-mono);
 font-size: 0.7rem;
 letter-spacing: 0.1em;
 text-transform: uppercase;
 color: var(--bg-elevated);
 background: linear-gradient(135deg, var(--accent-bright), var(--accent));
 padding: 0.38rem 0.8rem;
 border-radius: 999px;
 margin-bottom: 1.1rem;
 box-shadow: 0 6px 16px -8px var(--accent-line);
}
.featured-badge i { font-size: 0.8em; }

.post-hero {
 display: grid;
 grid-template-columns: 168px 1fr;
 gap: 1.5rem;
 align-items: center;
 background: var(--bg-elevated);
 border: 1px solid var(--rule);
 border-radius: var(--radius-lg);
 padding: 1.4rem;
 margin: 0 0 1.7rem;
 box-shadow: var(--shadow-soft);
}

.post-hero-art {
 width: 100%;
 aspect-ratio: 1 / 1.25;
 border-radius: var(--radius);
 overflow: hidden;
 border: 1px solid var(--rule-strong);
 background: var(--bg-soft);
}
.post-hero-art img {
 width: 100%;
 height: 100%;
 object-fit: cover;
 display: block;
 margin: 0;
 border: 0;
 border-radius: 0;
}

.post-hero-text { min-width: 0; }
.post-hero-text .post-meta { display: block; margin-bottom: 0.55rem; }
.post-hero-text h1 {
 font-size: 1.92rem;
 margin: 0.3rem 0 0.65rem;
 line-height: 1.16;
 letter-spacing: -0.015em;
}

.post-tagline {
 font-family: var(--font-display);
 font-style: italic;
 color: var(--accent);
 font-size: 1.05rem;
 margin: 0;
}

.hero-preprint-link { margin-top: 0.7rem; }

@media (max-width: 600px) {
 .post-hero { grid-template-columns: 104px 1fr; padding: 1rem; gap: 1rem; }
 .post-hero-text h1 { font-size: 1.4rem; }
}

/* =========================================================
  Cite box
  ========================================================= */

.note-cite {
 margin-top: 2.6rem;
 padding-top: 1.6rem;
 border-top: 1px solid var(--rule);
}
.note-cite h3 { font-family: var(--font-mono); font-size: 0.72rem; letter-spacing: 0.1em; text-transform: uppercase; color: var(--text-muted); margin-bottom: 0.9rem; }
.note-cite-line { font-size: 0.92rem; color: var(--text-body); margin-bottom: 0.8rem; }
.note-cite-box {
 position: relative;
 background: var(--bg-elevated);
 border: 1px solid var(--rule);
 border-radius: var(--radius);
 padding: 1rem 1.15rem;
}
.note-cite-box pre {
 margin: 0; font-family: var(--font-mono); font-size: 0.82rem; line-height: 1.6;
 color: var(--text-body); white-space: pre-wrap; word-break: break-word;
}
.note-cite-copy {
 position: absolute; top: 0.6rem; right: 0.6rem;
 font-family: var(--font-mono); font-size: 0.68rem; letter-spacing: 0.04em;
 color: var(--text-muted); background: var(--bg-soft); border: 1px solid var(--rule-strong);
 padding: 0.3rem 0.6rem; border-radius: var(--radius); cursor: pointer;
}
.note-cite-copy:hover { color: var(--accent); border-color: var(--accent-line); }
.note-cite-note { font-size: 0.78rem; color: var(--text-faint); margin-top: 0.6rem; }

/* =========================================================
  Related notes
  ========================================================= */

.note-related { margin-top: 2.6rem; padding-top: 1.6rem; border-top: 1px solid var(--rule); }
.note-related h3 { font-family: var(--font-mono); font-size: 0.72rem; letter-spacing: 0.1em; text-transform: uppercase; color: var(--text-muted); margin-bottom: 1rem; }
.note-related-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(240px, 1fr)); gap: 0.9rem; }
.note-related-card {
 display: block; background: var(--bg-elevated); border: 1px solid var(--rule); border-radius: var(--radius);
 padding: 1rem 1.1rem; background-image: none; transition: border-color 0.2s ease, transform 0.2s ease;
}
.note-related-card:hover { border-color: var(--accent-line); }
.note-related-kicker { font-family: var(--font-mono); font-size: 0.65rem; letter-spacing: 0.08em; text-transform: uppercase; color: var(--accent); margin-bottom: 0.4rem; display: block; }
.note-related-title { font-family: var(--font-display); font-weight: 600; font-size: 0.98rem; color: var(--text-primary); line-height: 1.4; }

@media (max-width: 600px) {
 .post-article-header h1 { font-size: 1.55rem; }
 body.notes .blog-hero h1 { font-size: 1.7rem; }
 .blog-hero-bar { flex-direction: column; align-items: flex-start; gap: 0.7rem; }
}

/* Shared "compact metadata line" — mono, dot-separated plain text.
   Used wherever a card/row needs date · type · series info without
   the visual weight of pills (pills stay reserved for the genuinely
   interactive tag/filter controls above). */
.meta-line {
  display: flex; flex-wrap: wrap; align-items: center; gap: 0;
  font-family: var(--font-mono); font-size: 0.74rem; letter-spacing: 0.03em;
  color: var(--text-muted);
}
.meta-line span:not(:last-child)::after { content: " \00b7 "; color: var(--rule-strong); }

.notes-section-head, .archive-section > .notes-section-head {
  display: flex; align-items: baseline; justify-content: space-between;
  margin: 0 auto 1.2rem; max-width: 780px; padding-bottom: 0.5rem; border-bottom: 1px solid var(--rule);
}
.notes-section-head h2 { font-size: 1.4rem; letter-spacing: -0.01em; }

/* =========================================================
   Featured note — full-width visual centerpiece.
   ========================================================= */
.featured-note {
  max-width: 780px; margin: 0 auto 2.8rem;
  display: grid; grid-template-columns: 260px 1fr; gap: 2.1rem; align-items: center;
  background: var(--bg-elevated); border: 1px solid var(--rule); border-radius: var(--radius-lg);
  padding: 1.8rem; box-shadow: var(--shadow-soft);
}
.featured-note-media {
  display: block; aspect-ratio: 1 / 1; border-radius: var(--radius); overflow: hidden;
  border: 1px solid var(--rule-strong); background: var(--bg-soft);
}
.featured-note-media img { width: 100%; height: 100%; object-fit: cover; display: block; }
.featured-note-kicker {
  display: inline-flex; align-items: center; font-family: var(--font-mono); font-size: 0.68rem;
  letter-spacing: 0.12em; text-transform: uppercase; color: var(--bg-elevated);
  background: linear-gradient(135deg, var(--accent-bright), var(--accent));
  padding: 0.32rem 0.75rem; border-radius: 999px; margin-bottom: 1.1rem;
}
.featured-note-title { font-size: 2rem; line-height: 1.12; letter-spacing: -0.02em; margin: 0 0 0.9rem; }
.featured-note-title a { color: var(--text-primary); background: none; }
.featured-note-title a:hover { color: var(--accent); }
.featured-note-desc { font-size: 1rem; color: var(--text-body); line-height: 1.65; margin: 0 0 0; max-width: 58ch; }
.featured-note .meta-line { margin: 0.9rem 0 1.2rem; }
.featured-note-actions { display: flex; flex-direction: column; align-items: flex-start; gap: 0.8rem; }
.featured-note-cta {
  display: inline-flex; align-items: center; gap: 0.55rem; font-family: var(--font-mono);
  font-size: 0.88rem; font-weight: 500; color: var(--bg-elevated); background: var(--accent);
  padding: 0.62rem 1.15rem; border-radius: var(--radius); background-image: none;
  transition: background-color 0.18s ease;
}
.featured-note-cta:hover { background: var(--accent-bright); }
.featured-note-cta i { font-size: 0.82em; }
.featured-note-companion {
  display: inline-flex; align-items: center; gap: 0.4rem; font-family: var(--font-mono);
  font-size: 0.78rem; color: var(--text-muted); background: none;
}
.featured-note-companion:hover { color: var(--accent); }

/* =========================================================
   Recent Notes — responsive 2-column editorial grid.
   ========================================================= */
.notes-section { max-width: 780px; margin: 0 auto 2.8rem; }
.notes-grid { display: grid; grid-template-columns: repeat(2, 1fr); gap: 1.3rem; }
.note-card {
  display: flex; flex-direction: column; background: var(--bg-elevated); border: 1px solid var(--rule);
  border-radius: var(--radius-lg); overflow: hidden; background-image: none;
  transition: border-color 0.2s ease, transform 0.2s ease, box-shadow 0.2s ease;
}
.note-card:hover { border-color: var(--accent-line); box-shadow: var(--shadow-soft); }
.card-thumb { display: block; aspect-ratio: 16 / 10; background: var(--bg-soft); overflow: hidden; }
.card-thumb img { width: 100%; height: 100%; object-fit: cover; display: block; transition: transform 0.4s ease; }
.note-card-title { display: block; font-family: var(--font-display); font-weight: 600; font-size: 1.05rem; color: var(--text-primary); line-height: 1.35; margin: 1.05rem 1.15rem 0; }
.note-card.is-textual .note-card-title { margin-top: 1.2rem; }
.note-card .meta-line { margin: 0.45rem 1.15rem 0; }
.note-card-desc { font-size: 0.87rem; color: var(--text-body); line-height: 1.55; margin: 0.6rem 1.15rem 0.9rem; flex: 1; }
.note-card-read { display: inline-flex; align-items: center; gap: 0.35rem; font-family: var(--font-mono); font-size: 0.76rem; color: var(--accent); background: none; margin: 0 1.15rem 1.1rem; }
.note-card-read i { font-size: 0.7em; }

/* =========================================================
   Series — curated collections, rule-separated rather than
   cards, so three items of very different length sit
   comfortably without forcing equal card heights.
   ========================================================= */
.series-section { max-width: 780px; margin: 0 auto 2.8rem; }
.series-block { border-top: 1px solid var(--rule); padding: 1.6rem 0.2rem; }
.series-block:first-of-type { border-top: 0; padding-top: 0.5rem; }
.series-block-head { display: flex; align-items: baseline; justify-content: space-between; gap: 1rem; flex-wrap: wrap; margin-bottom: 1rem; }
.series-block-head h3 { font-family: var(--font-display); font-size: 1.3rem; font-weight: 600; }
.series-block-head h3 a { color: var(--text-primary); background: none; }
.series-block-head h3 a:hover { color: var(--accent); }
.series-block-head p { font-family: var(--font-mono); font-size: 0.8rem; color: var(--text-muted); }
.series-parts { list-style: none; margin: 0 0 1rem; padding: 0; display: flex; flex-direction: column; gap: 0.55rem; }
.series-parts li { display: flex; align-items: baseline; gap: 0.8rem; }
.series-part-num { font-family: var(--font-mono); font-size: 0.76rem; color: var(--text-faint); width: 1.4rem; flex: none; }
.series-parts a { font-size: 0.96rem; color: var(--text-body); background: none; }
.series-parts a:hover { color: var(--accent); }
.series-explore { display: inline-block; font-family: var(--font-mono); font-size: 0.8rem; color: var(--accent); }
.series-explore:hover { color: var(--accent-bright); }

/* =========================================================
   Interactive companions — a distinct, dashed-border callout
   so interactivity reads as a different kind of content, not
   just another card in the grid.
   ========================================================= */
.interactive-section { max-width: 780px; margin: 0 auto 2.8rem; }
.interactive-card {
  display: block; background: var(--bg-soft); border: 1px dashed var(--accent-line);
  border-radius: var(--radius-lg); padding: 1.8rem 1.9rem; background-image: none;
  transition: border-color 0.2s ease, background-color 0.2s ease;
}
.interactive-card:hover { border-style: solid; background-color: var(--accent-soft); }
.interactive-card-kicker {
  display: inline-flex; align-items: center; gap: 0.4rem; font-family: var(--font-mono); font-size: 0.7rem;
  letter-spacing: 0.1em; text-transform: uppercase; color: var(--accent); margin-bottom: 0.8rem;
}
.interactive-card-text h3 { font-family: var(--font-display); font-size: 1.32rem; margin-bottom: 0.65rem; color: var(--text-primary); }
.interactive-card-text p { font-size: 0.94rem; color: var(--text-body); line-height: 1.6; max-width: 62ch; margin: 0 0 1.1rem; }
.interactive-card-cta { display: inline-flex; align-items: center; gap: 0.5rem; font-family: var(--font-mono); font-size: 0.84rem; color: var(--accent); font-weight: 500; }
.interactive-card-cta i { font-size: 0.8em; }

/* =========================================================
   Archive — compact, scannable, and the one place search and
   tag filtering actually act. Grows gracefully to hundreds of
   rows since each row is a single flex line.
   ========================================================= */
.archive-section { max-width: 780px; margin: 0 auto 3rem; }
.archive-year { font-family: var(--font-mono); font-size: 0.78rem; letter-spacing: 0.1em; color: var(--text-faint); margin: 1.5rem 0 0.3rem; }
.archive-year-group:first-of-type .archive-year { margin-top: 0.3rem; }
.archive-list { list-style: none; margin: 0; padding: 0; }
.archive-row { border-top: 1px solid var(--rule); }
.archive-row:first-child { border-top: 0; }
.archive-row a { display: flex; align-items: baseline; gap: 1.1rem; padding: 0.7rem 0.4rem; background: none; border-radius: var(--radius); }
.archive-row a:hover { background: var(--accent-soft); }
.archive-month { font-family: var(--font-mono); font-size: 0.74rem; color: var(--text-faint); width: 2.4rem; flex: none; text-transform: uppercase; }
.archive-title { flex: 1; font-size: 0.96rem; color: var(--text-primary); min-width: 0; }
.archive-row a:hover .archive-title { color: var(--accent); }
.archive-type { font-family: var(--font-mono); font-size: 0.72rem; color: var(--text-faint); white-space: nowrap; }

/* =========================================================
   Figure moments — an optional wider treatment for the one
   figure per visualization-heavy post (the 3D landscape) that
   earns more room than the standard 480px figure column.
   ========================================================= */
.post-article-body .post-figure.figure-wide img { max-width: 100%; }
.post-figure.figure-wide { max-width: 720px; margin-left: 50%; transform: translateX(-50%); }

/* =========================================================
   Series navigation — on individual article pages, for posts
   that belong to a numbered series (GA/ACO/SA, MDP, SQEP).
   ========================================================= */
.series-nav {
  max-width: 640px; margin: 2.6rem auto; background: var(--bg-elevated); border: 1px solid var(--rule);
  border-radius: var(--radius-lg); padding: 1.3rem 1.4rem;
}
.series-nav-label { font-family: var(--font-mono); font-size: 0.68rem; letter-spacing: 0.12em; text-transform: uppercase; color: var(--accent); margin-bottom: 0.9rem; display: block; }
.series-nav-parts { list-style: none; margin: 0 0 1rem; padding: 0; display: flex; flex-direction: column; gap: 0.45rem; }
.series-nav-parts li { display: flex; align-items: baseline; gap: 0.7rem; }
.series-nav-parts .series-part-num { font-family: var(--font-mono); font-size: 0.74rem; color: var(--text-faint); width: 1.3rem; flex: none; }
.series-nav-parts a { font-size: 0.92rem; color: var(--text-body); background: none; }
.series-nav-parts a:hover { color: var(--accent); }
.series-nav-parts .is-current { font-weight: 600; color: var(--text-primary); }
.series-nav-parts .is-current .series-part-num { color: var(--accent); }
.series-nav-pager {
  display: flex; align-items: center; justify-content: space-between; gap: 1rem;
  padding-top: 1rem; border-top: 1px dashed var(--rule);
  font-family: var(--font-mono); font-size: 0.82rem;
}
.series-nav-pager a { color: var(--accent); background: none; }
.series-nav-pager a:hover { color: var(--accent-bright); }
.series-nav-pager .series-nav-none { color: var(--text-faint); }

@media (max-width: 720px) {
  .featured-note { grid-template-columns: 1fr; padding: 1.4rem; gap: 1.3rem; }
  .featured-note-media { max-width: 220px; margin: 0 auto; }
  .featured-note-title { font-size: 1.5rem; }
  .notes-grid { grid-template-columns: 1fr; }
  .notes-section-head, .archive-section > .notes-section-head { max-width: none; }
}
@media (max-width: 600px) {
  .series-block-head { flex-direction: column; align-items: flex-start; gap: 0.3rem; }
  .archive-type { display: none; }
  .series-nav-pager { flex-direction: column; align-items: flex-start; gap: 0.5rem; }
}

/* Motion micro-interactions (small lift/slide/zoom on hover) only run
   when the visitor hasn't asked for reduced motion; the color/border/
   shadow feedback above still applies either way. */
@media (prefers-reduced-motion: no-preference) {
  .note-related-card:hover { transform: translateY(-2px); }
  .featured-note-cta:hover i { transform: translateX(3px); }
  .note-card:hover { transform: translateY(-2px); }
  .note-card:hover .card-thumb img { transform: scale(1.035); }
  .note-card:hover .note-card-read i { transform: translateX(3px); }
  .interactive-card:hover .interactive-card-cta i { transform: translateX(3px); }
  .surprise-btn:hover i { transform: rotate(50deg); }
}

/* =========================================================
   Soft Computing course file library
   ========================================================= */
body.notes .course-page-hero {
  margin-top: 0.25rem;
  margin-bottom: 2.2rem;
}
.course-materials {
  max-width: 780px;
  margin: 0 auto 3rem;
}
.course-materials > .notes-section-head {
  margin-bottom: 1.05rem;
}
.course-empty-state {
  display: flex;
  align-items: center;
  gap: 1rem;
  padding: 1.35rem 1.4rem;
  background: var(--bg-soft);
  border: 1px dashed var(--accent-line);
  border-radius: var(--radius-lg);
}
.course-empty-mark {
  display: grid;
  place-items: center;
  flex: 0 0 2.7rem;
  width: 2.7rem;
  height: 2.7rem;
  border: 1px solid var(--accent-line);
  border-radius: 50%;
  background: var(--bg-elevated);
  color: var(--accent);
  font-family: var(--font-mono);
  font-size: 0.7rem;
  letter-spacing: 0.05em;
}
.course-empty-title {
  margin: 0 0 0.25rem;
  color: var(--text-primary);
  font-family: var(--font-display);
  font-size: 1.05rem;
  font-weight: 600;
}
.course-empty-description {
  margin: 0;
  color: var(--text-muted);
  font-size: 0.9rem;
}
.course-file-list {
  list-style: none;
  margin: 0;
  padding: 0;
}
.course-file-item {
  display: flex;
  align-items: center;
  gap: 0.85rem;
  padding: 0.9rem 0.4rem;
  border-top: 1px solid var(--rule);
}
.course-file-item:first-child { border-top: 0; }
.course-file-type {
  flex: 0 0 3.2rem;
  min-width: 3.2rem;
  padding: 0.2rem 0.35rem;
  border: 1px solid var(--rule-strong);
  border-radius: var(--radius);
  color: var(--text-muted);
  font-family: var(--font-mono);
  font-size: 0.66rem;
  text-align: center;
  text-transform: uppercase;
}
.course-file-link {
  display: flex;
  flex: 1;
  align-items: center;
  justify-content: space-between;
  min-width: 0;
  gap: 1rem;
  color: var(--text-primary);
  background: none;
}
.course-file-link:hover .course-file-name { color: var(--accent); }
.course-file-name { overflow-wrap: anywhere; }
.course-file-action {
  flex: none;
  color: var(--text-muted);
  font-family: var(--font-mono);
  font-size: 0.72rem;
  white-space: nowrap;
}
@media (max-width: 600px) {
  .course-empty-state { align-items: flex-start; padding: 1.1rem; }
  .course-file-item { align-items: flex-start; gap: 0.6rem; }
  .course-file-link { flex-wrap: wrap; gap: 0.25rem 0.7rem; }
  .course-file-action { flex-basis: 100%; }
}