/* Default Cool Paper article treatment used by every tutorial lesson. */
@import url("lesson-base.css");

:root {
  --font-serif: Charter, "Bitstream Charter", "Sitka Text", "Iowan Old Style",
    Cambria, Georgia, "Times New Roman", serif;
  --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica,
    Arial, sans-serif;
  --bg: #f5f8f9;
  --ink: #232a2d;
  --ink-soft: #536066;
  --ink-faint: #869297;
  --rule: #dbe3e5;
  --rule-2: #c8d3d6;
  --panel: #edf2f3;
  --accent: #a94631;
  --accent-2: #a94631;
  --code-bg: #e8eef0;
  --measure: 40rem;
}

body {
  background: var(--bg);
  color: var(--ink);
  font-family: var(--font-serif);
  font-size: 1.125rem;
  line-height: 1.6;
  text-rendering: optimizeLegibility;
  font-kerning: normal;
}

::selection {
  background: #dcebef;
}

a {
  color: inherit;
  text-decoration-color: var(--rule-2);
  text-underline-offset: .15em;
  transition: color .15s ease, text-decoration-color .15s ease;
}

a:hover {
  color: var(--accent);
  text-decoration-color: currentColor;
}

a:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 3px;
  border-radius: 3px;
}

.site-head {
  max-width: var(--measure);
  margin: 0 auto;
  padding: 0 1.5rem;
  background: transparent;
  border: 0;
}

.site-head .series-tag {
  display: inline-block;
  max-width: none;
  margin: 3.5rem 0 2.5rem;
  padding: 0;
  color: var(--ink-faint);
  font-family: var(--font-sans);
  font-size: .9375rem;
  font-weight: 400;
  line-height: 1.4;
  letter-spacing: 0;
  text-transform: none;
  text-decoration: none;
}

.site-head .series-tag:hover {
  color: var(--accent);
}

.page {
  max-width: var(--measure);
  margin: 0 auto;
  padding: 0 1.5rem;
}

.article {
  max-width: none;
  margin: 0;
  padding: 0 0 2rem;
}

.article-head {
  margin: 0 0 2.25rem;
}

.article h1 {
  margin: 0 0 .6rem;
  color: var(--ink);
  font-family: var(--font-serif);
  font-size: 2.1rem;
  font-weight: 600;
  line-height: 1.15;
  letter-spacing: -.015em;
}

.article .meta {
  margin: 0;
  color: var(--ink-faint);
  font-family: var(--font-sans);
  font-size: .9375rem;
  font-weight: 400;
  line-height: 1.5;
}

.article .standfirst {
  margin: 2rem 0 0;
  padding: 0;
  border: 0;
  color: var(--ink-soft);
  font-family: var(--font-serif);
  font-size: 1.15rem;
  font-weight: 400;
  line-height: 1.62;
}

.article p {
  margin: 1.1rem 0;
}

.article ul,
.article ol {
  margin: 1.1rem 0;
  padding-left: 1.25em;
}

.article li {
  margin: .45rem 0;
}

.article strong {
  font-weight: 600;
}

.article a {
  color: inherit;
}

.article .citation {
  position: relative;
  display: inline-block;
  color: var(--accent);
  font-family: var(--font-sans);
  font-size: .78em;
  font-weight: 600;
  line-height: 1.3;
  text-decoration-thickness: .08em;
  white-space: nowrap;
}

.article .citation-card {
  position: absolute;
  bottom: calc(100% + .55rem);
  left: 50%;
  z-index: 20;
  box-sizing: border-box;
  width: min(24rem, calc(100vw - 3rem));
  padding: .65rem .75rem;
  visibility: hidden;
  border: 1px solid var(--rule-2);
  border-radius: 5px;
  background: var(--ink);
  box-shadow: 0 8px 24px rgb(35 42 45 / 18%);
  color: var(--bg);
  font-family: var(--font-sans);
  font-size: .8rem;
  font-weight: 400;
  line-height: 1.45;
  opacity: 0;
  pointer-events: none;
  text-align: left;
  white-space: normal;
  transform: translate(-50%, .25rem);
  transition: opacity .15s ease, transform .15s ease, visibility .15s ease;
}

.article .citation:hover .citation-card,
.article .citation:focus-visible .citation-card,
.article .footnote-ref:hover .citation-card,
.article .footnote-ref:focus-visible .citation-card {
  visibility: visible;
  opacity: 1;
  transform: translate(-50%, 0);
}

.article .footnote {
  margin-left: .12em;
  font-family: var(--font-sans);
  font-size: .72em;
  line-height: 0;
}

.article .footnote-ref {
  position: relative;
  display: inline-block;
  color: var(--accent);
  font-weight: 600;
  text-decoration: none;
}

.article .footnote-ref:hover,
.article .footnote-ref:focus-visible {
  text-decoration: underline;
}

.article h2 {
  margin: 2.75rem 0 .75rem;
  padding: 0;
  color: var(--ink);
  font-family: var(--font-serif);
  font-size: 1.5rem;
  font-weight: 600;
  line-height: 1.25;
  letter-spacing: -.01em;
  scroll-margin-top: 1.75rem;
}

.article h2::before {
  content: none;
}

.article h3 {
  margin: 2rem 0 .5rem;
  color: var(--ink);
  font-family: var(--font-serif);
  font-size: 1.18rem;
  font-weight: 600;
  line-height: 1.3;
}

.article code {
  font-family: "IBM Plex Mono", ui-monospace, monospace;
  background: var(--code-bg);
}

.katex-display {
  margin: 1.25rem 0;
}

.post-toc {
  display: none;
}

.post-toc-title {
  margin-bottom: .7rem;
  padding-left: .85rem;
  color: var(--ink-faint);
  font-size: .6875rem;
  font-weight: 600;
  letter-spacing: .08em;
  text-transform: uppercase;
}

.post-toc ul {
  margin: 0;
  padding: 0;
  list-style: none;
}

.post-toc a {
  display: block;
  padding: .3rem 0 .3rem .85rem;
  border-left: 2px solid var(--rule);
  color: var(--ink-faint);
  font-size: .8125rem;
  line-height: 1.35;
  text-decoration: none;
}

.post-toc a:hover {
  color: var(--ink);
  border-left-color: var(--ink-faint);
}

.post-toc a[aria-current="true"] {
  color: var(--accent);
  border-left-color: var(--accent);
}

details.deriv {
  margin: 1.75rem 0;
  border-color: var(--rule);
  border-radius: 6px;
  background: var(--panel);
}

details.deriv summary {
  color: var(--ink-soft);
  font-family: var(--font-sans);
  font-size: .75rem;
  letter-spacing: .035em;
}

details.deriv summary::before,
details.deriv[open] summary::before {
  color: var(--accent);
}

.note {
  border-color: var(--rule);
  border-left-color: var(--accent);
  background: var(--panel);
}

.note .note-label {
  color: var(--accent);
  font-family: var(--font-sans);
}

.table-wrap {
  margin: 1.75rem 0;
}

@media (min-width: 900px) {
  .table-wrap.table-wide {
    width: min-content;
    max-width: min(72rem, calc(50vw + var(--measure) / 2 - 3rem));
    overflow-x: visible;
  }

  .table-wrap.table-wide table {
    width: auto;
  }
}

.table-wrap.controller-table th,
.table-wrap.controller-table td {
  padding: 6px 8px;
}

.article table {
  font-family: var(--font-sans);
}

.article th {
  background: var(--panel);
  font-family: var(--font-sans);
}

figure.viewer {
  margin: 2.5rem 0;
}

.frame-label {
  color: var(--ink-soft);
  font-family: var(--font-sans);
  font-size: .6875rem;
  letter-spacing: .08em;
}

figure.viewer iframe,
figure.viewer img {
  border-color: var(--rule-2);
  border-radius: 6px;
}

figure.viewer figcaption {
  margin-top: .75rem;
  padding-left: 0;
  border: 0;
  color: var(--ink-faint);
  font-family: var(--font-sans);
  font-size: .875rem;
  line-height: 1.45;
  text-align: center;
}

figure.viewer figcaption b {
  color: var(--ink-soft);
}

.prevnext {
  margin: 3.5rem 0 0;
  padding-top: 1.5rem;
  border-color: var(--rule);
  font-family: var(--font-sans);
  font-size: .9375rem;
  font-weight: 400;
}

.prevnext a {
  color: var(--ink-faint);
}

.prevnext a:hover {
  color: var(--accent);
}

.article-author {
  margin: 1.25rem 0 0;
  color: var(--ink-faint);
  font-family: var(--font-sans);
  font-size: .8125rem;
  font-weight: 400;
  line-height: 1.5;
  text-align: right;
}

@media (min-width: 1024px) {
  :root {
    --measure: 48rem;
  }

  body {
    font-size: 1.0625rem;
  }

  .article h1 {
    font-size: 2.35rem;
  }
}

@media (min-width: 1280px) {
  .post-toc {
    display: block;
    position: fixed;
    top: 7rem;
    left: calc(50% - var(--measure) / 2 - 2rem - 12rem);
    width: 12rem;
    max-height: calc(100vh - 9rem);
    overflow-y: auto;
    color: var(--ink-faint);
    font-family: var(--font-sans);
  }
}

@media (max-width: 640px) {
  body {
    font-size: 1rem;
    line-height: 1.55;
  }

  .site-head,
  .page {
    padding-right: 1.25rem;
    padding-left: 1.25rem;
  }

  .site-head .series-tag {
    margin-top: 2.5rem;
  }

  .article h1 {
    font-size: 1.85rem;
  }

  .article .standfirst {
    font-size: 1.08rem;
  }

  .article .citation-card {
    position: fixed;
    right: 1.25rem;
    bottom: 1.25rem;
    left: 1.25rem;
    width: auto;
    transform: translateY(.25rem);
  }

  .article .citation:hover .citation-card,
  .article .citation:focus-visible .citation-card,
  .article .footnote-ref:hover .citation-card,
  .article .footnote-ref:focus-visible .citation-card {
    transform: translateY(0);
  }

}