:root {
  --teal: #1B6B73;
  --teal-light: #8CCBCF;
  --plum: #7A2E4D;
  --plum-light: #C98BA6;
  --mustard: #F0C75E;
  --bg: #FBF7F0;
  --ink: #2A2A2A;
  --muted: #6B6660;
  --card: #FFFFFF;
  --border: #E8E1D5;
}

* { box-sizing: border-box; }

body {
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  font-family: "Manrope", system-ui, sans-serif;
  line-height: 1.5;
}

header, main, footer {
  max-width: 960px;
  margin: 0 auto;
  padding: 0 16px;
}

header { padding-top: 48px; }

h1 {
  font-family: "Fraunces", Georgia, serif;
  font-weight: 700;
  font-size: clamp(2rem, 5vw, 3rem);
  color: var(--teal);
  margin: 0 0 4px;
}

.lede { font-size: 1.15rem; color: var(--muted); margin: 0 0 32px; }

/* the two controls sit side by side, and wrap onto two lines on a phone */
.controls {
  display: flex;
  flex-wrap: wrap;
  gap: 16px 32px;
  align-items: flex-end;
}
.control { flex: 0 1 360px; }
#rank-control { flex: 0 1 auto; }

.controls label,
.controls .label {
  display: block;
  font-weight: 600;
  margin-bottom: 6px;
}

/* two-button toggle */
.toggle {
  display: inline-flex;
  border: 2px solid var(--teal-light);
  border-radius: 10px;
  overflow: hidden;
  background: var(--card);
}
.toggle button {
  font: inherit;
  border: 0;
  background: transparent;
  color: var(--ink);
  padding: 9px 16px;
  cursor: pointer;
}
.toggle button + button { border-left: 2px solid var(--teal-light); }
.toggle button:hover:not([aria-pressed="true"]):not(:disabled) { background: #EEF6F6; }
/* the selected option: filled, bold, with a tick */
.toggle button[aria-pressed="true"] { background: var(--teal); color: #fff; font-weight: 600; }
.toggle button[aria-pressed="true"]::before { content: "✓ "; }
.toggle button:focus-visible { outline: 3px solid var(--mustard); outline-offset: -3px; }
.toggle button:disabled { opacity: 0.4; cursor: not-allowed; }

.explain {
  font-size: 0.9rem;
  color: var(--muted);
  max-width: 70ch;
  margin-bottom: 32px;
}
.explain p { margin: 0 0 8px; }
.explain b { color: var(--ink); }

#search {
  width: 100%;
  padding: 10px 14px;
  font: inherit;
  border: 2px solid var(--teal-light);
  border-radius: 10px;
  background: var(--card);
}
#search:focus { outline: none; border-color: var(--teal); }

.note { font-size: 0.85rem; color: var(--muted); margin: 8px 0 0; }

.summary {
  display: flex;
  flex-wrap: wrap;
  gap: 16px;
  margin: 28px 0 8px;
}

.stat {
  flex: 1 1 160px;
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 14px 18px;
  display: flex;
  flex-direction: column;
}
.stat-value {
  font-family: "Fraunces", Georgia, serif;
  font-size: 1.8rem;
  font-weight: 500;
  color: var(--plum);
}
.stat-label { font-size: 0.85rem; color: var(--muted); }

.chart {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 12px;
  margin: 16px 0 32px;
  min-height: 320px;
  padding: 8px;
}
.placeholder { color: var(--muted); text-align: center; padding: 120px 16px; margin: 0; }

footer {
  font-size: 0.85rem;
  color: var(--muted);
  padding-bottom: 40px;
}
a { color: var(--teal); }

/* ---------- Page links at the top (both pages) ---------- */
.top-nav { display: flex; flex-wrap: wrap; gap: 4px 20px; margin-bottom: 20px; font-size: 0.95rem; }
.top-nav a { color: var(--ink); text-decoration: none; font-weight: 600; padding: 4px 0; }
.top-nav a:hover, .top-nav a[aria-current="page"] {
  color: var(--teal);
  text-decoration: underline; text-decoration-color: var(--mustard);
  text-decoration-thickness: 3px; text-underline-offset: 6px;
}

/* ---------- About page: long text ---------- */
.toc { font-size: 0.95rem; margin: -16px 0 24px; }
.prose h2:first-child { margin-top: 8px; }
.prose h2 { font-family: "Fraunces", Georgia, serif; color: var(--teal); font-size: 1.6rem; margin: 40px 0 12px; }
.prose h3 { font-family: "Fraunces", Georgia, serif; font-size: 1.15rem; margin: 28px 0 8px; }
.prose p, .prose li { max-width: 70ch; }
.prose li { margin-bottom: 8px; }
.prose code { font-size: 0.88em; background: #F1ECE3; padding: 1px 5px; border-radius: 4px; }
.prose .why { color: var(--muted); font-size: 0.95rem; border-left: 3px solid var(--mustard); padding-left: 12px; }
.prose .math { overflow-x: auto; }
.table-wrap { overflow-x: auto; margin: 8px 0 20px; }
.prose table { border-collapse: collapse; font-size: 0.92rem; background: var(--card); border: 1px solid var(--border); border-radius: 8px; }
.prose th, .prose td { text-align: left; padding: 8px 12px; border-bottom: 1px solid var(--border); vertical-align: top; }
.prose th { font-weight: 600; background: #F4F9F9; }
.prose table.num td + td { text-align: right; font-variant-numeric: tabular-nums; }
.prose tr:last-child td { border-bottom: 0; }
footer { padding-top: 24px; }