Blame for app/src/styles/_layout.css

/* ============================================================================ */
/* Page grid (tokens in _grid.css)                                              */
/* ---------------------------------------------------------------------------- */
/* .content-grid holds the TOC rail and <main> on the same row; <main> spans    */
/* the screen and repeats the same named lines, so every block picks a column:  */
/* body by default, .wide and .full-width break out, sidenotes go to margin.    */
/* ============================================================================ */

.content-grid {
  display: grid;
  grid-template-columns: var(--layout-cols);
  align-items: start;
  margin-top: var(--layout-content-top);
}

.content-grid > main {
  grid-column: screen;
  grid-row: 1;
  display: grid;
  grid-template-columns: var(--layout-cols);
  align-content: start;
  min-width: 0;
  margin: 0;
  padding: 0;
}

.content-grid > main > * {
  grid-column: body;
  min-width: 0;
}

/* The first body line, the first TOC line and the first sidenote share a top edge */
.content-grid > main > :first-child {
  margin-top: 0;
}

/* Prose measure */
.content-grid > main > :is(p, ul, ol, h2, h3, h4, blockquote) {
  max-width: var(--layout-prose);
}

.content-grid > main :is(p, li) {
  font-size: var(--layout-prose-font-size);
}

/* Long references, URLs and DOIs wrap inside their column; inline citations never break */
.sidenote,
.footer li,
.meta-col {
  overflow-wrap: anywhere;
}

.content-grid main a[href^="#bib-"] {
  white-space: nowrap;
}

/* ============================================================================ */
/* Width helpers                                                                */
/* ============================================================================ */

.wide,
.full-width {
  box-sizing: border-box;
  position: relative;
  z-index: var(--z-elevated);
}

.content-grid > main > .wide,
.content-grid > main > .html-embed--wide {
  grid-column: body-start / margin-end;
}

/* <HtmlEmbed wide> follows the grid instead of its own centered 1100px box */
.content-grid > main > .html-embed--wide {
  width: auto;
  margin-left: 0;
  padding: 0;
  transform: none;
  border-radius: 0;
  -webkit-mask: none;
  mask: none;
}

.content-grid > main > .full-width {
  grid-column: screen;
  padding: var(--spacing-5);
  background: color-mix(in srgb, var(--primary-color) 5%, var(--surface-bg));
  border-block: 1px solid var(--border-color);
}

.full-width > * {
  max-width: 1800px;
  margin-inline: auto;
}

.full-width figure figcaption {
  text-align: center !important;
}

@media (--bp-content-collapse) {
  .content-grid > main > :is(.wide, .html-embed--wide) {
    grid-column: screen;
    padding-inline: var(--layout-outer);
  }

  .content-grid > main > .full-width {
    padding: var(--spacing-4) var(--layout-outer);
  }
}

/* ============================================================================ */
/* Theme toggle placement                                                       */
/* ============================================================================ */

#theme-toggle {
  position: absolute;
  top: var(--spacing-4);
  left: var(--spacing-4);
  margin: 0;
  z-index: var(--z-overlay);
  width: 40px;
  height: 40px;
  border-radius: 50%;
  border: 1px solid var(--border-color);
  background: var(--page-bg);
  box-shadow: 0 2px 12px rgba(0, 0, 0, .08);
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 0;
  cursor: pointer;
  color: var(--text-color);
  transition: transform 150ms ease, box-shadow 150ms ease;
}

#theme-toggle:active {
  transform: scale(0.92);
}

@media (--bp-content-collapse) {
  #theme-toggle {
    top: var(--spacing-2);
    left: var(--spacing-2);
    width: 36px;
    height: 36px;
  }
}

/* ------------------------------------------------------------------------- */
/* D3 neural embed responsiveness                                            */
/* Stack canvas (left) over network (right) on small screens                 */
/* ------------------------------------------------------------------------- */
@media (--bp-md) {
  .d3-neural .panel {
    flex-direction: column;
  }

  .d3-neural .panel .left {
    flex: 0 0 auto;
    width: 100%;
  }

  .d3-neural .panel .right {
    flex: 0 0 auto;
    width: 100%;
    min-width: 0;
  }
}

/* ============================================================================ */
/* Auto figure numbering                                                        */
/* Applies a CSS counter across all figure-bearing components:                  */
/* Reference (.reference-wrapper), Image (.image-wrapper figure),               */
/* and HtmlEmbed (.html-embed)                                                  */
/* ============================================================================ */

.content-grid > main {
  counter-reset: figure;
}

/* Increment on every figure-like component */
.content-grid > main .reference-wrapper,
.content-grid > main .image-wrapper > figure,
.content-grid > main figure.html-embed {
  counter-increment: figure;
}

/* Display "Figure N · " before each figcaption */
.content-grid > main .reference-wrapper .reference__caption::before,
.content-grid > main .image-wrapper > figure > figcaption::before,
.content-grid > main figure.html-embed > .html-embed__desc::before {
  content: "Figure " counter(figure) " · ";
  font-weight: 600;
}

/* ============================================================================ */
/* "paper" template - academic project-page layout (single centered column)     */
/* Activated by frontmatter `template: "paper"` -> data-template="paper"        */
/* The single column itself comes from the paper tokens in _grid.css.           */
/* ============================================================================ */

/* ---- Paper hero banner: placed between meta and content in index.astro ---- */

.paper-hero-banner {
  max-width: 920px;
  margin: 32px auto 0;
  padding: 0 16px;
}

.paper-hero-banner .html-embed {
  border-radius: 8px;
  overflow: hidden;
}

.paper-hero-banner .html-embed__card {
  border-radius: 8px;
}

/* Thin separator between banner area and content */
[data-template="paper"] .paper-hero-banner + .content-grid {
  margin-top: 48px;
  border-top: 1px solid var(--border-color);
  padding-top: 40px;
}

/* When no banner, separator is directly below meta */
[data-template="paper"] .hero-paper-meta + .content-grid {
  margin-top: 32px;
  border-top: 1px solid var(--border-color);
  padding-top: 40px;
}

[data-template="paper"] .table-of-contents,
[data-template="paper"] .toc-topbar {
  display: none;
}

/* ---- Typography: clean left-aligned headings ---- */

[data-template="paper"] .content-grid > main h2 {
  text-align: left;
  font-size: 1.75em;
  font-weight: 700;
  margin-top: 2.5em;
  margin-bottom: 0.8em;
  border-bottom: none;
  padding-bottom: 0;
}

[data-template="paper"] .content-grid > main > h2:first-child {
  margin-top: 0;
}

[data-template="paper"] .content-grid > main h3 {
  font-size: 1.3em;
  font-weight: 600;
  margin-top: 2em;
  margin-bottom: 0.6em;
}

[data-template="paper"] .content-grid > main :is(p, li) {
  font-size: inherit;
}

/* ---- No figure numbering ---- */

[data-template="paper"] .content-grid > main {
  counter-reset: none;
}

[data-template="paper"] .content-grid > main .reference-wrapper .reference__caption::before,
[data-template="paper"] .content-grid > main .image-wrapper > figure > figcaption::before,
[data-template="paper"] .content-grid > main figure.html-embed > .html-embed__desc::before {
  content: none;
}

/* ---- Footer: headings above their content ---- */

[data-template="paper"] .footer-inner > * > .footer-heading {
  grid-column: body;
  justify-self: start;
  text-align: left;
  padding-right: 0;
  margin-top: 16px;
  margin-bottom: 8px;
}

[data-template="paper"] .template-credit p {
  margin-top: 32px;
}