/* ─── Reset & base ─────────────────────────────────────────────────────── */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

:root {
  --c-low:      #ef4444;
  --c-below:    #f97316;
  --c-above:    #eab308;
  --c-high:     #22c55e;
  --c-elite:    #3b82f6;
  --c-current:  #7c3aed;
  --bg:         #f8fafc;
  --surface:    #ffffff;
  --border:     #e2e8f0;
  --text:       #1e293b;
  --muted:      #64748b;
  --accent:     #3b82f6;
  --better:     #16a34a;
  --worse:      #dc2626;
  --radius:     8px;
  --shadow:     0 1px 3px rgba(0,0,0,.08), 0 1px 2px rgba(0,0,0,.06);
}

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.6;
  font-size: 15px;
}

a { color: var(--accent); text-decoration: none; }
a:hover { text-decoration: underline; }

/* ─── Layout ───────────────────────────────────────────────────────────── */
.site-header {
  background: var(--surface);
  border-bottom: 1px solid var(--border);
  padding: 0 1.5rem;
}
.site-header nav {
  max-width: 960px;
  margin: 0 auto;
  display: flex;
  align-items: center;
  gap: 2rem;
  height: 56px;
}
.site-header .logo {
  font-weight: 700;
  font-size: 1rem;
  color: var(--text);
  white-space: nowrap;
  margin-right: auto;
}
.site-header .nav-links { display: flex; gap: 2rem; }
.site-header nav a { color: var(--muted); font-size: 0.9rem; }
.site-header nav a:hover { color: var(--text); text-decoration: none; }

/* Burger menu */
.burger {
  display: none;
  background: none;
  border: none;
  font-size: 1.5rem;
  cursor: pointer;
  color: var(--text);
  padding: 0.25rem;
  margin-left: auto;
}
@media (max-width: 600px) {
  .burger { display: block; }
  .site-header .nav-links {
    display: none;
    flex-direction: column;
    gap: 0;
    position: absolute;
    top: 56px;
    left: 0;
    right: 0;
    background: var(--surface);
    border-bottom: 1px solid var(--border);
    box-shadow: var(--shadow);
    z-index: 100;
  }
  .site-header .nav-links.open { display: flex; }
  .site-header .nav-links a {
    padding: 0.75rem 1.5rem;
    border-top: 1px solid var(--border);
  }
  .site-header { position: relative; }
}

main {
  max-width: 960px;
  margin: 0 auto;
  padding: 2rem 1.5rem 4rem;
}

.page-intro {
  margin-bottom: 2rem;
}
.page-intro h1 {
  font-size: 1.75rem;
  font-weight: 700;
  margin-bottom: 0.4rem;
}
.page-intro p { color: var(--muted); max-width: 65ch; }

/* ─── Cards ────────────────────────────────────────────────────────────── */
.card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  padding: 1.5rem;
  margin-bottom: 1.5rem;
}
.card h2 {
  font-size: 1.1rem;
  font-weight: 600;
  margin-bottom: 1.2rem;
  padding-bottom: 0.6rem;
  border-bottom: 1px solid var(--border);
}
.card h3 {
  font-size: 0.95rem;
  font-weight: 600;
  color: var(--muted);
  text-transform: uppercase;
  letter-spacing: 0.04em;
  margin: 1.2rem 0 0.6rem;
}

/* ─── Form ──────────────────────────────────────────────────────────────── */
.form-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1rem;
}
@media (max-width: 600px) { .form-grid { grid-template-columns: 1fr; } }

.field { display: flex; flex-direction: column; gap: 0.3rem; }
.field label { font-size: 0.875rem; font-weight: 500; color: var(--muted); }
.field input[type="number"] {
  border: 1px solid var(--border);
  border-radius: 6px;
  padding: 0.5rem 0.75rem;
  font-size: 1rem;
  width: 100%;
  background: var(--bg);
  transition: border-color .15s;
}
.field input[type="number"]:focus {
  outline: none;
  border-color: var(--accent);
  box-shadow: 0 0 0 3px rgba(59,130,246,.15);
}
.field-hint {
  font-size: 0.78rem;
  color: var(--muted);
}

.radio-group {
  display: flex;
  gap: 1rem;
  margin-top: 0.2rem;
}
.radio-group label {
  display: flex;
  align-items: center;
  gap: 0.4rem;
  font-size: 0.95rem;
  font-weight: 400;
  color: var(--text);
  cursor: pointer;
}

.checkbox-group {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 0.5rem;
}
@media (max-width: 500px) { .checkbox-group { grid-template-columns: 1fr; } }
.checkbox-group label {
  display: flex;
  align-items: flex-start;
  gap: 0.5rem;
  font-size: 0.875rem;
  cursor: pointer;
  line-height: 1.4;
}
.checkbox-group input[type="checkbox"] { margin-top: 2px; flex-shrink: 0; }

details summary {
  cursor: pointer;
  user-select: none;
  font-size: 0.875rem;
  color: var(--accent);
  margin: 0.6rem 0 0.8rem;
  list-style: none;
}
details summary::before { content: '▸ '; }
details[open] summary::before { content: '▾ '; }

.btn {
  display: inline-block;
  padding: 0.65rem 1.75rem;
  background: var(--accent);
  color: #fff;
  border: none;
  border-radius: 6px;
  font-size: 1rem;
  font-weight: 600;
  cursor: pointer;
  transition: background .15s;
  margin-top: 1rem;
}
.btn:hover { background: #2563eb; }

.form-errors {
  display: none;
  margin-top: 0.75rem;
  padding: 0.75rem 1rem;
  background: #fef2f2;
  border: 1px solid #fecaca;
  border-radius: 6px;
  color: var(--worse);
  font-size: 0.875rem;
  list-style: inside;
}

/* ─── Hero results ──────────────────────────────────────────────────────── */
#hero-fitness, #hero-mortality {
  font-size: 1rem;
  line-height: 1.7;
  margin-bottom: 0.6rem;
}
#hero-mortality { color: var(--muted); }

.cat-Low      { color: var(--c-low); }
.cat-BelowAvg { color: var(--c-below); }
.cat-AboveAvg { color: var(--c-above); }
.cat-High     { color: var(--c-high); }
.cat-Elite    { color: var(--c-elite); }

/* ─── Mortality table ───────────────────────────────────────────────────── */
.table-wrap { overflow-x: auto; }
table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.875rem;
}
th {
  text-align: left;
  font-weight: 600;
  font-size: 0.78rem;
  text-transform: uppercase;
  letter-spacing: 0.04em;
  color: var(--muted);
  padding: 0.5rem 0.75rem;
  border-bottom: 2px solid var(--border);
}
td {
  padding: 0.55rem 0.75rem;
  border-bottom: 1px solid var(--border);
  vertical-align: middle;
}
tr.current-row td {
  background: #f5f3ff;
  font-weight: 600;
}
.range-cell { color: var(--muted); font-size: 0.8rem; }
.better { color: var(--better); }
.worse  { color: var(--worse);  }

.cat-dot {
  display: inline-block;
  width: 10px; height: 10px;
  border-radius: 50%;
  margin-right: 6px;
  vertical-align: middle;
}
.cat-dot.cat-Low      { background: var(--c-low); }
.cat-dot.cat-BelowAvg { background: var(--c-below); }
.cat-dot.cat-AboveAvg { background: var(--c-above); }
.cat-dot.cat-High     { background: var(--c-high); }
.cat-dot.cat-Elite    { background: var(--c-elite); }

/* ─── Chart ─────────────────────────────────────────────────────────────── */
.chart-container { height: 360px; margin: 1.2rem 0; }
@media (max-width: 600px) { .chart-container { height: 300px; } }

/* ─── Equivalents ───────────────────────────────────────────────────────── */
#equivalents-container {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1rem;
  margin-top: 0.5rem;
}
@media (max-width: 640px) { #equivalents-container { grid-template-columns: 1fr; } }

.equiv-card {
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1rem;
  background: var(--surface);
}
.equiv-card.equiv-better {
  border-left: 4px solid var(--better);
  background: #f0fdf4;
}
.equiv-card.equiv-worse {
  border-left: 4px solid var(--worse);
  background: #fef2f2;
}

.equiv-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 0.5rem;
  margin-bottom: 0.75rem;
}
.equiv-label {
  font-weight: 600;
  font-size: 0.95rem;
}
.equiv-dir-label {
  font-size: 0.8rem;
  color: var(--muted);
}
.cat-badge {
  font-size: 0.78rem;
  font-weight: 700;
  padding: 0.15rem 0.5rem;
  border-radius: 4px;
  background: #f1f5f9;
}
.cat-badge.cat-Low      { color: var(--c-low);   background: #fef2f2; }
.cat-badge.cat-BelowAvg { color: var(--c-below); background: #fff7ed; }
.cat-badge.cat-AboveAvg { color: #92400e;        background: #fefce8; }
.cat-badge.cat-High     { color: var(--c-high);  background: #f0fdf4; }
.cat-badge.cat-Elite    { color: var(--c-elite); background: #eff6ff; }

.equiv-dir-label { font-size: 0.8rem; color: var(--muted); margin-left: auto; }

.equiv-sentence { font-size: 0.875rem; margin-bottom: 0.5rem; line-height: 1.5; }
.equiv-items {
  font-size: 0.875rem;
  display: flex;
  flex-wrap: wrap;
  gap: 0.4rem;
  margin-bottom: 0.5rem;
}
.equiv-item {
  white-space: nowrap;
  cursor: help;
  position: relative;
}
.equiv-val { font-weight: 700; }
.equiv-tip {
  font-size: 0.7rem;
  color: var(--muted);
  margin-left: 2px;
  vertical-align: super;
  line-height: 1;
}
.equiv-le { font-size: 0.8rem; color: var(--muted); }

/* ─── Risk factor breakdown table ───────────────────────────────────────── */
#risk-breakdown { margin-top: 1rem; display: none; }
#risk-breakdown h4 { font-size: 0.9rem; font-weight: 600; margin-bottom: 0.5rem; }
.rf-table { font-size: 0.85rem; margin-bottom: 0.5rem; }
.rf-table td { padding: 0.3rem 0.6rem; }
.rf-note { font-size: 0.8rem; color: var(--muted); }

/* ─── Caveats ────────────────────────────────────────────────────────────── */
.caveat-list {
  margin: 0.5rem 0 0 1.2rem;
  font-size: 0.875rem;
  color: var(--muted);
  line-height: 1.7;
}

/* ─── Footer ─────────────────────────────────────────────────────────────── */
.site-footer {
  text-align: center;
  padding: 1.5rem;
  font-size: 0.8rem;
  color: var(--muted);
  border-top: 1px solid var(--border);
  background: var(--surface);
}
.site-footer a { color: var(--muted); }

/* ─── Methodology page ───────────────────────────────────────────────────── */
.methodology-body {
  max-width: 72ch;
  margin: 0 auto;
  padding: 2rem 1.5rem 4rem;
}
.methodology-body h1 { font-size: 1.75rem; margin-bottom: 0.5rem; }
.methodology-body h2 {
  font-size: 1.2rem;
  font-weight: 700;
  margin: 2.5rem 0 0.75rem;
  padding-bottom: 0.4rem;
  border-bottom: 2px solid var(--border);
}
.methodology-body h3 {
  font-size: 1rem;
  font-weight: 600;
  margin: 1.5rem 0 0.5rem;
}
.methodology-body p { margin-bottom: 0.9rem; line-height: 1.75; }
.methodology-body ul, .methodology-body ol {
  margin: 0.5rem 0 0.9rem 1.5rem;
  line-height: 1.7;
}
.math-block {
  background: #f8fafc;
  border: 1px solid var(--border);
  border-left: 4px solid var(--accent);
  border-radius: 4px;
  padding: 0.5rem 1rem;
  overflow-x: auto;
  margin: 0.75rem 0 1rem;
}
.math-block .katex-display { margin: 0.25rem 0; }
.math-block .katex { font-size: 1rem; }
.ref-list {
  list-style: decimal;
  padding-left: 1.5rem;
  font-size: 0.875rem;
  line-height: 1.8;
  color: var(--text);
}
.ref-list li { margin-bottom: 0.4rem; }

.warning-box {
  background: #fef9c3;
  border: 1px solid #fde047;
  border-radius: 6px;
  padding: 0.75rem 1rem;
  font-size: 0.875rem;
  margin: 1rem 0;
}

/* ─── Utility ────────────────────────────────────────────────────────────── */
/* ─── Metric toggle ─────────────────────────────────────────────────────── */
.metric-toggle {
  display: inline-flex;
  border: 1px solid var(--border);
  border-radius: 6px;
  overflow: hidden;
  margin-bottom: 1.2rem;
  background: var(--bg);
}
.metric-option {
  cursor: pointer;
  margin: 0;
}
.metric-option input[type="radio"] {
  position: absolute;
  opacity: 0;
  pointer-events: none;
}
.metric-option span {
  display: block;
  padding: 0.45rem 1.2rem;
  font-size: 0.875rem;
  font-weight: 500;
  color: var(--muted);
  transition: background .15s, color .15s;
  border-right: 1px solid var(--border);
}
.metric-option:last-child span {
  border-right: none;
}
.metric-option input[type="radio"]:checked + span {
  background: var(--accent);
  color: #fff;
}

.muted { color: var(--muted); }
.small { font-size: 0.8rem; }
.mt-1 { margin-top: 0.5rem; }
.mt-2 { margin-top: 1rem; }