on the page is the page title. / .sidebar .brand { font-family: 'Helvetica Neue', Arial, sans-serif; font-size: 18px; /
is not bold by default;

/* FW 536 Lab Stylesheet
 * Used by all lab pages on the standard course site.
 */

:root {
  --osu-orange: #D73F09;
  --osu-orange-dark: #B33107;
  --osu-black: #000000;
  --osu-stone: #4A4A4A;
  --osu-cream: #F4ECD8;
  --bg: #FBFAF6;
  --panel: #FFFFFF;
  --panel-alt: #F1EFE8;
  --border: #DDD7C7;
  --text: #1B1B1B;
  --muted: #6B6B6B;
  --accent: #2B6E61;
  --warn: #B47B00;
  --bad: #A22020;
  --good: #2E6B2A;
  --code-bg: #1E1E1E;
  --code-fg: #E8E8E8;
  --code-comment: #8FA08F;
  --code-string: #E5A66B;
  --code-keyword: #C586C0;
  --code-number: #B5CEA8;
  --code-fn: #DCDCAA;
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  font-family: 'Charter', 'Iowan Old Style', Georgia, 'Times New Roman', serif;
  font-size: 17px;
  line-height: 1.65;
  color: var(--text);
  background: var(--bg);
  margin: 0;
  padding: 0;
}

/* Layout */
.shell { display: grid; grid-template-columns: 280px 1fr; min-height: 100vh; }
.sidebar {
  background: var(--osu-black);
  color: #fff;
  padding: 24px 18px;
  position: sticky;
  top: 0;
  height: 100vh;
  overflow-y: auto;
  border-right: 6px solid var(--osu-orange);
}
/* Sidebar brand. The sidebar uses <p class="brand"> so the only <h1> on the
   page is the page title. */
.sidebar .brand {
  font-family: 'Helvetica Neue', Arial, sans-serif;
  font-size: 18px;
  /* <p> is not bold by default; <h1> was. Restore the weight explicitly. */
  font-weight: 700;
  margin: 0 0 4px 0;
  color: #fff;
  letter-spacing: 0.5px;
}
.sidebar .brand a {
  color: #fff;
  text-decoration: none;
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 7px 10px;
  border-radius: 5px;
  border-left: 3px solid var(--osu-orange);
  background: rgba(215,63,9,0.10);
}
.sidebar .brand a::before {
  content: "\2190";
  font-size: 14px;
  color: var(--osu-orange);
  font-weight: bold;
}
.sidebar .brand a:hover {
  background: var(--osu-orange);
  color: #fff;
}
.sidebar .brand a:hover::before { color: #fff; }
.sidebar .subtitle { color: #c8c8c8; font-size: 12px; margin: 6px 0 24px 0; padding: 0 10px; }
.sidebar nav ul { list-style: none; padding: 0; margin: 0; }
.sidebar nav li { margin: 6px 0; }
.sidebar nav a {
  color: #e8e8e8;
  text-decoration: none;
  font-size: 14px;
  padding: 6px 10px;
  display: block;
  border-radius: 4px;
  border-left: 3px solid transparent;
}
.sidebar nav a:hover { background: rgba(215,63,9,0.18); border-left-color: var(--osu-orange); color: #fff; }
.sidebar nav a.featured {
  font-size: 16px;
  font-weight: 600;
  background: rgba(255,255,255,0.07);
  border-left-color: var(--osu-orange);
  padding: 9px 10px;
}
.sidebar nav a.featured:hover { background: rgba(215,63,9,0.30); color: #fff; }
.sidebar nav .section { color: var(--osu-orange); font-size: 11px; text-transform: uppercase; letter-spacing: 1px; margin: 18px 0 4px 10px; }

.content { padding: 40px 60px 120px 60px; max-width: 1100px; }

/* Header */
.lab-header {
  border-bottom: 4px solid var(--osu-orange);
  padding-bottom: 18px;
  margin-bottom: 32px;
}
.lab-header .eyebrow {
  font-family: 'Helvetica Neue', Arial, sans-serif;
  text-transform: uppercase;
  letter-spacing: 2px;
  font-size: 12px;
  color: var(--osu-orange);
  font-weight: 700;
}
.lab-header h1 {
  font-family: 'Helvetica Neue', Arial, sans-serif;
  font-size: 36px;
  margin: 4px 0 6px 0;
  color: var(--osu-black);
  line-height: 1.15;
}
.lab-header .lede {
  font-size: 19px;
  color: var(--osu-stone);
  font-style: italic;
}

/* Sections */
section { margin: 40px 0; }
h2 {
  font-family: 'Helvetica Neue', Arial, sans-serif;
  font-size: 26px;
  border-bottom: 2px solid var(--border);
  padding-bottom: 6px;
  color: var(--osu-black);
}
h3 {
  font-family: 'Helvetica Neue', Arial, sans-serif;
  color: var(--osu-orange-dark);
  font-size: 20px;
  margin-top: 28px;
}
h4 {
  font-family: 'Helvetica Neue', Arial, sans-serif;
  color: var(--osu-stone);
  font-size: 16px;
  text-transform: uppercase;
  letter-spacing: 1px;
}

/* Callouts */
.callout {
  border-left: 5px solid var(--accent);
  background: var(--panel);
  padding: 16px 22px;
  margin: 24px 0;
  border-radius: 0 8px 8px 0;
  box-shadow: 0 1px 3px rgba(0,0,0,0.04);
}
.callout.plain {
  border-left-color: var(--osu-orange);
  background: #FFF9F2;
}
.callout.plain::before {
  content: "Plain-language summary";
  display: block;
  font-family: 'Helvetica Neue', Arial, sans-serif;
  font-size: 11px;
  letter-spacing: 1.5px;
  text-transform: uppercase;
  color: var(--osu-orange);
  margin-bottom: 6px;
  font-weight: 700;
}
.callout.bio {
  border-left-color: #4A8C3A;
  background: #F4FAF1;
}
.callout.bio::before {
  content: "Biological intuition";
  display: block;
  font-family: 'Helvetica Neue', Arial, sans-serif;
  font-size: 11px;
  letter-spacing: 1.5px;
  text-transform: uppercase;
  color: #2E6B2A;
  margin-bottom: 6px;
  font-weight: 700;
}
.callout.warn {
  border-left-color: var(--warn);
  background: #FFF8E5;
}
.callout.warn::before {
  content: "Watch out";
  display: block;
  font-family: 'Helvetica Neue', Arial, sans-serif;
  font-size: 11px;
  letter-spacing: 1.5px;
  text-transform: uppercase;
  color: var(--warn);
  margin-bottom: 6px;
  font-weight: 700;
}
.callout.key {
  border-left-color: var(--osu-orange);
  background: #F8F4E8;
}
.callout.key::before {
  content: "Key idea";
  display: block;
  font-family: 'Helvetica Neue', Arial, sans-serif;
  font-size: 11px;
  letter-spacing: 1.5px;
  text-transform: uppercase;
  color: var(--osu-orange);
  margin-bottom: 6px;
  font-weight: 700;
}
.callout.try {
  border-left-color: var(--accent);
  background: #EAF4F2;
}
.callout.try::before {
  content: "Try it yourself";
  display: block;
  font-family: 'Helvetica Neue', Arial, sans-serif;
  font-size: 11px;
  letter-spacing: 1.5px;
  text-transform: uppercase;
  color: var(--accent);
  margin-bottom: 6px;
  font-weight: 700;
}

/* Lab navigation / table of contents card (appears at top of each lab.html) */
.lab-toc {
  background: white;
  border-radius: 14px;
  padding: 28px 32px;
  margin: 24px 0 40px 0;
  box-shadow: 0 4px 22px rgba(0,0,0,0.08);
  border: 2px solid var(--osu-orange);
}
.lab-toc h2 {
  border: none;
  font-size: 22px;
  margin: 0 0 8px 0;
  padding: 0;
  color: var(--osu-black);
  font-family: 'Helvetica Neue', Arial, sans-serif;
}
.lab-toc .toc-intro {
  color: var(--osu-stone);
  margin: 0 0 22px 0;
  font-size: 15px;
  line-height: 1.5;
}
.lab-toc .session {
  display: grid;
  grid-template-columns: 130px 1fr;
  gap: 18px;
  padding: 18px 0;
  border-top: 1px solid var(--border);
}
.lab-toc .session:first-of-type { border-top: none; padding-top: 8px; }
.lab-toc .session-label {
  font-family: 'Helvetica Neue', Arial, sans-serif;
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 1.5px;
  text-transform: uppercase;
  color: var(--osu-orange);
  padding-top: 4px;
}
.lab-toc .session-title {
  font-family: 'Helvetica Neue', Arial, sans-serif;
  font-size: 17px;
  font-weight: 600;
  color: var(--osu-black);
  margin-bottom: 10px;
}
.lab-toc .row {
  display: flex;
  align-items: flex-start;
  gap: 12px;
  padding: 6px 0;
  font-size: 14px;
}
.lab-toc .row .tag {
  font-family: 'Helvetica Neue', Arial, sans-serif;
  font-size: 10px;
  font-weight: 700;
  letter-spacing: 1px;
  text-transform: uppercase;
  padding: 3px 8px;
  border-radius: 12px;
  white-space: nowrap;
  flex-shrink: 0;
}
.lab-toc .tag.practice { background: #E8F2D9; color: #3F6B2A; }
.lab-toc .tag.assessed { background: #FBE3DD; color: #A22020; }
.lab-toc .tag.template { background: #E1ECF7; color: #1C638A; }
.lab-toc .tag.lecture  { background: #F4ECD8; color: #6A3F22; }
.lab-toc .row a {
  color: var(--osu-orange-dark);
  text-decoration: none;
  font-weight: 600;
}
.lab-toc .row a:hover { color: var(--osu-orange); text-decoration: underline; }
.lab-toc .row .note { color: var(--muted); font-size: 13px; margin-left: 4px; }

/* Banner that goes ABOVE the practice problems making it clear they are
   practice and not the hand-in. */
.practice-banner {
  background: linear-gradient(90deg, #E8F2D9, #F4FAF1);
  border-left: 6px solid #4A8C3A;
  padding: 16px 22px;
  margin: 30px 0;
  border-radius: 0 10px 10px 0;
}
.practice-banner .label {
  font-family: 'Helvetica Neue', Arial, sans-serif;
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 1.5px;
  text-transform: uppercase;
  color: #2E6B2A;
}
.practice-banner h3 {
  font-family: 'Helvetica Neue', Arial, sans-serif;
  font-size: 18px;
  color: #1B4B1B;
  margin: 4px 0 6px 0;
}
.practice-banner p { margin: 4px 0; font-size: 14px; }
.practice-banner .hand-in {
  display: inline-block;
  margin-top: 8px;
  padding: 4px 10px;
  border-radius: 4px;
  background: white;
  border: 1px solid #A22020;
  color: #A22020;
  font-family: 'Helvetica Neue', Arial, sans-serif;
  font-size: 13px;
  font-weight: 600;
  text-decoration: none;
}
.practice-banner .hand-in:hover { background: #A22020; color: white; }

/* Plain-language primer banner — prominent, whole-block "read this first" link */
.primer-banner {
  display: block;
  text-decoration: none;
  background: linear-gradient(90deg, #FDEBD9, #FFF9F2);
  border-left: 6px solid var(--osu-orange);
  padding: 16px 22px;
  margin: 30px 0;
  border-radius: 0 10px 10px 0;
  transition: background .15s, box-shadow .15s;
}
.primer-banner:hover {
  background: linear-gradient(90deg, #FBDCC0, #FFF3E4);
  box-shadow: 0 3px 12px rgba(215,63,9,0.15);
}
.primer-banner .label {
  display: block;
  font-family: 'Helvetica Neue', Arial, sans-serif;
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 1.5px;
  text-transform: uppercase;
  color: var(--osu-orange);
}
.primer-banner .pb-title {
  display: block;
  font-family: 'Helvetica Neue', Arial, sans-serif;
  font-size: 18px;
  font-weight: 700;
  color: var(--osu-black);
  margin: 4px 0 6px 0;
}
.primer-banner .pb-desc {
  display: block;
  color: var(--osu-stone);
  font-size: 14px;
  line-height: 1.6;
}
.primer-banner .pb-cta {
  display: inline-block;
  margin-top: 10px;
  padding: 4px 10px;
  border-radius: 4px;
  background: white;
  border: 1px solid var(--osu-orange);
  color: var(--osu-orange-dark);
  font-family: 'Helvetica Neue', Arial, sans-serif;
  font-size: 13px;
  font-weight: 700;
}
.primer-banner:hover .pb-cta { background: var(--osu-orange); color: white; }

/* Exercises */
.exercise {
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 22px 26px;
  margin: 28px 0;
  box-shadow: 0 2px 8px rgba(0,0,0,0.05);
}
.exercise .ex-tag {
  display: inline-block;
  background: var(--osu-orange);
  color: white;
  font-family: 'Helvetica Neue', Arial, sans-serif;
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 1px;
  padding: 4px 10px;
  border-radius: 4px;
  text-transform: uppercase;
}
.exercise h3 { margin-top: 8px; color: var(--osu-black); }
.exercise .difficulty {
  font-family: 'Helvetica Neue', Arial, sans-serif;
  font-size: 12px;
  color: var(--muted);
  margin-left: 12px;
}
.exercise .difficulty.easy { color: var(--good); }
.exercise .difficulty.medium { color: var(--warn); }
.exercise .difficulty.hard { color: var(--bad); }

/* Reveal answer */
details.answer {
  margin: 16px 0 0 0;
  background: var(--panel-alt);
  border-radius: 8px;
  padding: 0;
  border: 1px dashed var(--border);
}
details.answer > summary {
  cursor: pointer;
  font-family: 'Helvetica Neue', Arial, sans-serif;
  font-weight: 600;
  font-size: 14px;
  color: var(--osu-orange-dark);
  list-style: none;
  padding: 12px 18px;
  user-select: none;
}
details.answer > summary::-webkit-details-marker { display: none; }
details.answer > summary::before {
  content: "▶ ";
  display: inline-block;
  transform-origin: 50% 50%;
  transition: transform 0.15s ease;
  margin-right: 6px;
}
details.answer[open] > summary::before { transform: rotate(90deg); }
details.answer > summary:hover { background: #E8E4D5; }
details.answer .answer-body { padding: 4px 22px 18px 22px; }

/* Code */
pre, code { font-family: 'JetBrains Mono', 'Source Code Pro', Menlo, Consolas, monospace; }
code { background: #EFEBE0; padding: 1px 5px; border-radius: 3px; font-size: 0.93em; }
pre {
  background: var(--code-bg);
  color: var(--code-fg);
  padding: 18px 20px;
  border-radius: 8px;
  overflow-x: auto;
  font-size: 14px;
  line-height: 1.55;
  box-shadow: inset 0 0 0 1px #2A2A2A;
}
pre code { background: transparent; color: inherit; padding: 0; }
pre .cm { color: var(--code-comment); font-style: italic; }   /* comment */
pre .kw { color: var(--code-keyword); }                          /* keyword */
pre .st { color: var(--code-string); }                           /* string */
pre .nu { color: var(--code-number); }                           /* number */
pre .fn { color: var(--code-fn); }                               /* function */
pre .op { color: #CFCFCF; }                                       /* operator */

.code-label {
  display: inline-block;
  background: #2D2D2D;
  color: #E0E0E0;
  font-family: 'Helvetica Neue', Arial, sans-serif;
  font-size: 11px;
  letter-spacing: 1px;
  text-transform: uppercase;
  padding: 4px 10px;
  border-radius: 4px 4px 0 0;
  margin-bottom: 0;
}
.code-label + pre { border-radius: 0 8px 8px 8px; margin-top: 0; }

/* Tables */
table {
  border-collapse: collapse;
  margin: 18px 0;
  width: 100%;
  background: var(--panel);
  border-radius: 6px;
  overflow: hidden;
}
th, td { padding: 10px 14px; text-align: left; border-bottom: 1px solid var(--border); }
th { background: var(--panel-alt); font-family: 'Helvetica Neue', Arial, sans-serif; font-size: 13px; text-transform: uppercase; letter-spacing: 0.5px; color: var(--osu-stone); }
tr:last-child td { border-bottom: none; }

/* Math */
.math { font-style: italic; font-family: 'Latin Modern Math', 'Cambria Math', Georgia, serif; }
.eq { text-align: center; margin: 18px 0; font-size: 18px; }
.eq-block {
  background: var(--panel-alt);
  border-left: 4px solid var(--osu-orange);
  padding: 12px 18px;
  margin: 18px 0;
  border-radius: 0 6px 6px 0;
  font-size: 18px;
  text-align: center;
  overflow-x: auto;
}

/* Quiz */
.quiz {
  background: var(--panel);
  border: 2px solid var(--accent);
  border-radius: 10px;
  padding: 22px 26px;
  margin: 28px 0;
}
.quiz h4 {
  margin-top: 0;
  color: var(--accent);
  display: flex;
  align-items: center;
  gap: 10px;
}
.quiz h4::before { content: "?"; background: var(--accent); color: white; border-radius: 50%; width: 24px; height: 24px; display: inline-flex; align-items: center; justify-content: center; font-weight: bold; }
.quiz .choices { list-style: none; padding: 0; margin: 14px 0; }
.quiz .choices li { padding: 8px 0; }
.quiz .choices label { cursor: pointer; display: flex; align-items: flex-start; gap: 10px; }
.quiz .choices input { margin-top: 4px; }
.quiz .feedback { margin-top: 14px; padding: 12px 16px; border-radius: 6px; display: none; font-size: 14px; }
.quiz .feedback.show { display: block; }
.quiz .feedback.correct { background: #E0F2D9; color: var(--good); }
.quiz .feedback.wrong { background: #FBE3DD; color: var(--bad); }
.quiz button {
  font-family: 'Helvetica Neue', Arial, sans-serif;
  background: var(--accent);
  color: white;
  border: none;
  padding: 8px 18px;
  border-radius: 4px;
  cursor: pointer;
  font-size: 14px;
  font-weight: 600;
}
.quiz button:hover { background: #224F46; }

/* Tabs */
.tabs { margin: 24px 0; }
.tab-buttons {
  display: flex;
  gap: 4px;
  border-bottom: 2px solid var(--border);
}
.tab-buttons button {
  background: transparent;
  border: none;
  padding: 10px 18px;
  font-family: 'Helvetica Neue', Arial, sans-serif;
  font-size: 14px;
  font-weight: 600;
  color: var(--muted);
  cursor: pointer;
  border-bottom: 3px solid transparent;
  margin-bottom: -2px;
}
.tab-buttons button.active { color: var(--osu-orange); border-bottom-color: var(--osu-orange); }
.tab-buttons button:hover { color: var(--osu-orange-dark); }
.tab-panel { display: none; padding: 18px 0; }
.tab-panel.active { display: block; }

/* Difficulty pills */
.pill {
  display: inline-block;
  font-family: 'Helvetica Neue', Arial, sans-serif;
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 0.5px;
  padding: 3px 10px;
  border-radius: 12px;
  text-transform: uppercase;
}
.pill.easy { background: #E0F2D9; color: var(--good); }
.pill.medium { background: #FFF1D6; color: var(--warn); }
.pill.hard { background: #FBE3DD; color: var(--bad); }
.pill.r { background: #E1ECF7; color: #1C638A; }
.pill.nimble { background: #F0E4F5; color: #6C2C8A; }
.pill.jags { background: #E8DACE; color: #6A3F22; }

/* Figure */
figure { margin: 22px 0; }
figure svg { max-width: 100%; height: auto; display: block; margin: 0 auto; background: white; border: 1px solid var(--border); border-radius: 6px; }
figcaption { font-size: 13px; color: var(--muted); text-align: center; margin-top: 8px; font-style: italic; }

/* Footer */
footer {
  border-top: 1px solid var(--border);
  padding: 30px 60px;
  font-size: 13px;
  color: var(--muted);
  background: var(--panel-alt);
  margin-top: 60px;
}

/* Print */
@media print {
  .sidebar { display: none; }
  .shell { grid-template-columns: 1fr; }
  details.answer { border: 1px solid #888; }
  details.answer .answer-body { display: block !important; }
  details.answer summary::before { content: ""; }
  pre { background: #f4f4f4 !important; color: #111 !important; box-shadow: none; border: 1px solid #ddd; }
}

/* Mobile */
@media (max-width: 900px) {
  .shell { grid-template-columns: 1fr; }
  .sidebar { position: relative; height: auto; border-right: none; border-bottom: 6px solid var(--osu-orange); }
  .content { padding: 24px; }
}


/* Data files & R scripts card on lab pages */
.data-card {
  background: white;
  border-left: 5px solid var(--accent);
  border-radius: 8px;
  padding: 22px 28px;
  margin: 30px 0;
  box-shadow: 0 2px 10px rgba(0,0,0,0.04);
}
.data-card h2 {
  border: none;
  font-size: 22px;
  margin: 0 0 6px 0;
  padding: 0;
  color: var(--osu-black);
}
.data-card > p { color: var(--osu-stone); font-size: 14px; margin: 0 0 16px 0; }
.data-card .data-h {
  font-family: 'Helvetica Neue', Arial, sans-serif;
  text-transform: uppercase;
  letter-spacing: 1.5px;
  font-size: 12px;
  color: var(--accent);
  margin: 14px 0 6px 0;
  border: none;
}
.data-card .data-row {
  padding: 6px 0;
  display: grid;
  grid-template-columns: 240px 1fr;
  gap: 16px;
  align-items: baseline;
  border-bottom: 1px solid var(--border);
  font-size: 14px;
}
.data-card .data-row:last-child { border-bottom: none; }
.data-card .data-row a {
  color: var(--osu-orange-dark);
  text-decoration: none;
  font-weight: 600;
}
.data-card .data-row a:hover { color: var(--osu-orange); text-decoration: underline; }
.data-card .data-row a code { background: #F0EAD2; padding: 2px 6px; border-radius: 3px; font-size: 13px; }
.data-card .data-row .data-desc { color: var(--osu-stone); font-size: 13px; }

/* ---- Interactive explorer: spoken readout + data tables ----
 * .sr-readout is announced by screen readers (role=status / aria-live=polite)
 * AND kept visible: low-vision and sighted users benefit from the same
 * plain-text statement of the current parameters and derived quantities.
 */
.sr-readout {
  font-family: 'Helvetica Neue', Arial, sans-serif;
  font-size: 15px;
  line-height: 1.55;
  background: var(--panel-alt);
  border: 1px solid var(--border);
  border-left: 5px solid var(--osu-orange);
  border-radius: 0 8px 8px 0;
  padding: 10px 14px;
  margin: 12px 0;
  color: var(--text);
}
.data-table-details { margin: 12px 0; }
.data-table-details > summary {
  font-family: 'Helvetica Neue', Arial, sans-serif;
  font-size: 14px;
  font-weight: 600;
  color: var(--osu-orange-dark);
  cursor: pointer;
  padding: 6px 0;
}
.data-table-details > summary:focus-visible { outline: 3px solid var(--osu-orange); outline-offset: 2px; }
.data-table-wrap { max-height: 22em; overflow: auto; border: 1px solid var(--border); }
.data-table-wrap table { border-collapse: collapse; width: 100%; font-size: 13px; }
.data-table-wrap caption {
  caption-side: top;
  text-align: left;
  font-family: 'Helvetica Neue', Arial, sans-serif;
  font-size: 13px;
  color: var(--muted);
  padding: 6px 8px;
}
.data-table-wrap th, .data-table-wrap td {
  border: 1px solid var(--border);
  padding: 3px 8px;
  text-align: right;
  font-variant-numeric: tabular-nums;
}
.data-table-wrap th { background: var(--panel-alt); position: sticky; top: 0; }