title — the hero panel renders its own styled

/* ─────────────────────────────────────────────────────────────────────────
   Design tokens (mirrored from lean-lang.org's Verso theme).
   Light theme is the default; .dark-theme on <html> opts into dark.
   ───────────────────────────────────────────────────────────────────────── */

:root {
  /* Typography */
  --font-primary: 'Open Sans', Arial, sans-serif;
  --font-secondary: var(--font-primary);
  --font-mono: 'Fira Code', 'IBM Plex Mono', 'SFMono-Regular', monospace;

  --fs-xs:   0.75rem;
  --fs-sm:   0.875rem;
  --fs-base: 1rem;
  --fs-md:   17px;
  --fs-lg:   1.25rem;
  --fs-xl:   2rem;
  --fs-2xl:  3.3rem;

  /* Spacing */
  --space-1:  0.25rem;
  --space-2:  0.5rem;
  --space-3:  0.75rem;
  --space-4:  1rem;
  --space-5:  1.25rem;
  --space-6:  1.5rem;
  --space-8:  2rem;
  --space-10: 2.5rem;
  --space-12: 3rem;
  --space-14: 4rem;
  --space-16: 5rem;

  --radius-sm:   0.25rem;
  --radius-md:   0.5rem;
  --radius-lg:   1rem;
  --radius-pill: 9999px;

  --container-width: 1240px;
  --transition-fast: 0.2s;
  --transition-base: 0.3s;

  /* Light palette */
  --color-primary:        #386EE0;
  --color-primary-light:  #4a90e2;
  --color-primary-focus:  #1D4ED8;
  --color-text:           #333;
  --color-text-contrast:  #fff;
  --color-text-light:     #64748b;
  --color-muted:          #607D8B;
  --color-bg:             #F9FBFD;
  --color-bg-translucent: rgba(249, 251, 253, 0.85);
  --color-surface:        #ffffff;
  --color-surface-soft:   #f4f7fc;
  --color-border:         #E4EBF3;
  --color-border-light:   #D1D9E2;
  --color-hover:          rgba(56, 110, 224, 0.08);
  --color-shadow:         rgba(35, 55, 139, 0.10);

  /* Lean-blue token coloring for code blocks */
  --tok-keyword: var(--color-primary);
  --tok-const:   #7c4dcc;
  --tok-var:     #1D4ED8;
  --tok-default: var(--color-text);

  /* Lattice (read by background.js) */
  --lattice-thin: rgba(56, 110, 224, 0.06);
  --lattice-bold: rgba(56, 110, 224, 0.10);

  /* Two signature shadow recipes lifted from lean-lang.org */
  --long-shadow:
      0px 14px 30px 0px rgba(35, 55, 139, 0.10),
      0px 124px 74px 0px rgba(35, 55, 139, 0.05),
      0px 55px 55px 0px rgba(35, 55, 139, 0.04);
  --soft-shadow:
      0px 6px 12px rgba(35, 55, 139, 0.06),
      0px 12px 20px rgba(35, 55, 139, 0.04);
}

.dark-theme {
  --color-primary:        #3b94ff;
  --color-primary-light:  #6aadfe;
  --color-primary-focus:  #669df6;
  --color-text:           #eee;
  --color-text-contrast:  #fff;
  --color-text-light:     #b9c3c9;
  --color-muted:          #90a4ae;
  --color-bg:             #181818;
  --color-bg-translucent: rgba(24, 24, 24, 0.85);
  --color-surface:        #1e1e1e;
  --color-surface-soft:   #232830;
  --color-border:         #2f3540;
  --color-border-light:   #3a4150;
  --color-hover:          rgba(255, 255, 255, 0.08);
  --color-shadow:         rgba(0, 0, 0, 0.5);

  --tok-keyword: #8db4ff;
  --tok-const:   #c5a5ff;
  --tok-var:     #9fc7ff;
  --tok-default: var(--color-text);

  --lattice-thin: rgba(127, 175, 255, 0.045);
  --lattice-bold: rgba(170, 200, 255, 0.07);

  --long-shadow:
      0px 14px 30px 0px rgba(0, 0, 0, 0.45),
      0px 124px 74px 0px rgba(0, 0, 0, 0.25),
      0px 55px 55px 0px rgba(0, 0, 0, 0.18);
  --soft-shadow:
      0px 6px 12px rgba(0, 0, 0, 0.35),
      0px 12px 20px rgba(0, 0, 0, 0.25);
}

/* ─────────────────────────────────────────────────────────────────────────
   Reset
   ───────────────────────────────────────────────────────────────────────── */

html {
  box-sizing: border-box;
  font-size: 16px;
  scroll-behavior: smooth;
  scroll-padding-top: 96px;
}

*, *::before, *::after { box-sizing: inherit; }

body, h1, h2, h3, h4, p, ul, ol, pre {
  margin: 0;
  padding: 0;
}

a { color: var(--color-primary); }

body {
  min-height: 100vh;
  background: var(--color-bg);
  color: var(--color-text);
  font-family: var(--font-primary);
  font-size: var(--fs-base);
  line-height: 1.5;
  transition: background-color var(--transition-base), color var(--transition-base);
}

/* Soft radial wash, in the spirit of lean-lang.org's .hero-radial-blur. */
body::before {
  content: "";
  position: fixed;
  inset: 0;
  pointer-events: none;
  z-index: -1;
  background:
    radial-gradient(circle at top left,    rgba(56, 110, 224, 0.06), transparent 38%),
    radial-gradient(circle at bottom right, rgba(56, 110, 224, 0.04), transparent 32%);
  animation: breathe 18s ease-in-out infinite alternate;
}

.dark-theme body::before {
  background:
    radial-gradient(circle at top left,    rgba(80, 140, 240, 0.08), transparent 38%),
    radial-gradient(circle at bottom right, rgba(80, 140, 240, 0.05), transparent 32%);
}

@keyframes breathe {
  from { opacity: 0.55; }
  to   { opacity: 0.95; }
}

/* ─────────────────────────────────────────────────────────────────────────
   Layout primitives
   ───────────────────────────────────────────────────────────────────────── */

.wrap {
  width: min(1120px, calc(100vw - 48px));
  margin: 0 auto;
}

.site-shell {
  display: flex;
  flex-direction: column;
  min-height: 100vh;
}

.page {
  padding: var(--space-10) 0 var(--space-12);
  flex-grow: 1;
}

/* ─────────────────────────────────────────────────────────────────────────
   Topbar (mirrors lean-lang.org's .site-header / .navbar / .nav-link)
   ───────────────────────────────────────────────────────────────────────── */

.topbar {
  position: sticky;
  top: 0;
  z-index: 1000;
  background-color: var(--color-bg-translucent);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--color-border);
  transition:
    background-color var(--transition-base),
    border-color var(--transition-base);
}

.topbar-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-6);
  min-height: 72px;
  padding: var(--space-3) 0;
}

.wordmark {
  display: inline-flex;
  align-items: center;
  gap: var(--space-3);
  text-decoration: none;
  color: var(--color-text);
  font-size: 25px;
  font-weight: 300;
  transition: color var(--transition-base);
}

.wordmark:hover { color: var(--color-primary); }

.wordmark:focus-visible {
  outline: 2px solid var(--color-primary);
  outline-offset: 4px;
  border-radius: var(--radius-sm);
}

.wordmark-mark {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 40px;
  height: 40px;
  border: 1.5px solid var(--color-primary);
  border-radius: var(--radius-md);
  color: var(--color-primary);
  font-family: var(--font-mono);
  font-size: 1.25rem;
  font-weight: 500;
}

.wordmark-text {
  font-size: inherit;
  font-weight: 300;
  letter-spacing: 0.005em;
}

nav.top ol {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  list-style: none;
}

nav.top a {
  display: inline-flex;
  align-items: center;
  padding: var(--space-2) var(--space-4);
  border-radius: var(--radius-md);
  color: var(--color-text);
  font-size: 0.9rem;
  font-weight: 500;
  text-decoration: none;
  transition:
    background-color var(--transition-fast),
    color var(--transition-fast);
}

nav.top a:hover {
  color: var(--color-primary);
  background: var(--color-hover);
}

nav.top a:focus-visible {
  outline: 2px solid var(--color-primary);
  outline-offset: 2px;
  color: var(--color-primary);
}

nav.top .home { display: none; }

.topbar-actions {
  display: flex;
  align-items: center;
  gap: var(--space-3);
}

.theme-toggle {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 36px;
  height: 36px;
  padding: 0;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  background: transparent;
  color: var(--color-text);
  cursor: pointer;
  font-size: 1rem;
  line-height: 1;
  transition:
    background-color var(--transition-fast),
    border-color var(--transition-fast),
    color var(--transition-fast);
}

.theme-toggle:hover {
  border-color: var(--color-primary);
  color: var(--color-primary);
  background: var(--color-hover);
}

.theme-toggle:focus-visible {
  outline: 2px solid var(--color-primary);
  outline-offset: 2px;
}

.theme-toggle .icon-sun,
.theme-toggle .icon-moon {
  display: inline-block;
  font-size: 1.05rem;
  line-height: 1;
}

.theme-toggle .icon-moon { display: none; }
.theme-toggle .icon-sun  { display: inline-block; }

.dark-theme .theme-toggle .icon-sun  { display: none; }
.dark-theme .theme-toggle .icon-moon { display: inline-block; }

.topbar-github {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 36px;
  height: 36px;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  color: var(--color-text);
  text-decoration: none;
  transition:
    background-color var(--transition-fast),
    border-color var(--transition-fast),
    color var(--transition-fast);
}

.topbar-github:hover {
  border-color: var(--color-primary);
  color: var(--color-primary);
  background: var(--color-hover);
}

.topbar-github:focus-visible {
  outline: 2px solid var(--color-primary);
  outline-offset: 2px;
}

.topbar-github svg {
  width: 18px;
  height: 18px;
  fill: currentColor;
}

/* ─────────────────────────────────────────────────────────────────────────
   Footer
   ───────────────────────────────────────────────────────────────────────── */

.footer {
  border-top: 1px solid var(--color-border);
  padding: var(--space-6) 0 var(--space-10);
  background-color: var(--color-bg-translucent);
  backdrop-filter: blur(10px);
  transition:
    background-color var(--transition-base),
    border-color var(--transition-base);
}

.footer-inner {
  display: flex;
  flex-direction: column;
  gap: var(--space-3);
  color: var(--color-text-light);
  font-size: 0.88rem;
}

.footer-inner a {
  color: var(--color-text-light);
  text-decoration: none;
  transition: color var(--transition-fast);
}

.footer-inner a:hover { color: var(--color-primary); }

.footer-inner a:focus-visible {
  outline: 2px solid var(--color-primary);
  outline-offset: 2px;
  color: var(--color-primary);
  border-radius: var(--radius-sm);
}

/* ─────────────────────────────────────────────────────────────────────────
   Page wrappers, prose, headings
   ───────────────────────────────────────────────────────────────────────── */

.leaderboard-root {
  width: min(1120px, calc(100vw - 48px));
  margin: var(--space-8) auto 0;
}

.prose { color: var(--color-text); }

.prose p {
  max-width: 72ch;
  margin-bottom: var(--space-4);
  line-height: 1.6;
}

.prose ul,
.prose ol {
  max-width: 72ch;
  margin: 0 0 var(--space-5);
  padding-left: 1.35rem;
}

.prose li { margin-bottom: var(--space-2); }

.prose a:not(.cta-button) {
  color: var(--color-primary);
  text-decoration: none;
  background: linear-gradient(transparent 80%, rgba(56, 110, 224, 0.12) 80%);
}

.prose a:not(.cta-button):hover { color: var(--color-primary-focus); }

.page-copy {
  margin-top: var(--space-8);
  margin-bottom: var(--space-8);
  padding: var(--space-8) var(--space-10);
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  box-shadow: var(--soft-shadow);
}

.page-copy .prose { max-width: 980px; }

.page-copy .prose > h1 {
  margin-bottom: var(--space-5);
  font-family: var(--font-secondary);
  font-size: clamp(2.4rem, 4vw, 3.3rem);
  font-weight: 400;
  line-height: 1.05;
  color: var(--color-text);
}

.page-copy .prose > h2 {
  margin-top: var(--space-10);
  margin-bottom: var(--space-5);
  padding-top: var(--space-5);
  border-top: 1px solid var(--color-border);
  color: var(--color-text);
  font-family: var(--font-secondary);
  font-size: 2rem;
  font-weight: 400;
}

.page-copy .prose > p + h2 { margin-top: var(--space-8); }

.page-copy .prose > h3 {
  margin-top: var(--space-8);
  margin-bottom: var(--space-3);
  font-family: var(--font-primary);
  font-size: 1.25rem;
  font-weight: 600;
  line-height: 1.18;
  color: var(--color-text);
}

.page-copy .prose > h2 + h3 { margin-top: var(--space-5); }

.page-copy .prose > h3:not(:first-of-type) {
  padding-top: var(--space-6);
  border-top: 1px solid var(--color-border);
}

.page-copy .prose code {
  font-family: var(--font-mono);
  font-size: 0.92em;
  color: var(--color-text);
  background: var(--color-surface-soft);
  padding: 1px 6px;
  border-radius: var(--radius-sm);
  border: 1px solid var(--color-border);
}

/* Inline "tag pill" pattern after h3, used as section labels */
.page-copy .prose > h3 + p code {
  display: inline-flex;
  align-items: center;
  padding: 0.35rem 0.85rem;
  border-radius: var(--radius-pill);
  background: rgba(56, 110, 224, 0.10);
  border: 1px solid rgba(56, 110, 224, 0.25);
  color: var(--color-primary);
  font-size: 0.78rem;
  font-weight: 600;
  letter-spacing: 0.02em;
}

/* ─────────────────────────────────────────────────────────────────────────
   Hero panel (mirrors lean-lang.org's .hero-bottom recipe:
   white card, 2px primary border, long shadow, serif display title)
   ───────────────────────────────────────────────────────────────────────── */

.hero-panel,
.leaderboard-panel,
.error-panel,
.loading-panel {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  box-shadow: var(--soft-shadow);
}

.hero-panel {
  border: 2px solid var(--color-primary);
  box-shadow: var(--long-shadow);
  padding: var(--space-8);
  margin-bottom: var(--space-6);
}

.hero-grid {
  display: grid;
  grid-template-columns: minmax(0, 1.2fr) minmax(280px, 0.8fr);
  gap: var(--space-8);
}

.hero-kicker,
.panel-kicker,
.section-label,
.theorem-card-label,
.catalog-kicker {
  display: inline-block;
  color: var(--color-primary);
  font-size: 0.72rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.12em;
}

.hero-panel h1,
.panel-header h2 {
  font-family: var(--font-secondary);
  font-weight: 400;
  letter-spacing: -0.01em;
  color: var(--color-text);
}

.hero-panel h1 {
  margin-top: var(--space-3);
  font-size: clamp(2.6rem, 4.5vw, 3.5rem);
  line-height: 1.04;
  max-width: 14ch;
}

.hero-copy {
  margin-top: var(--space-5);
  max-width: 66ch;
  color: var(--color-text-light);
  font-size: var(--fs-md);
  line-height: 1.5;
}

.hero-stats {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-4);
  margin-top: var(--space-8);
}

.hero-side {
  align-self: stretch;
  padding: var(--space-1) 0 0 var(--space-5);
  border-left: 1px solid var(--color-border);
}

.hero-side-copy,
.empty-lead,
.catalog-notes {
  color: var(--color-text-light);
}

.hero-side-copy {
  margin-top: var(--space-4);
  max-width: 30ch;
  font-size: 0.95rem;
  line-height: 1.5;
}

.hero-stat {
  display: block;
  min-width: 130px;
  padding: var(--space-4) var(--space-5);
  border-radius: var(--radius-md);
  background: var(--color-surface-soft);
  border: 1px solid var(--color-border);
  transition:
    border-color var(--transition-fast),
    background-color var(--transition-fast),
    transform var(--transition-fast),
    box-shadow var(--transition-fast);
}

.hero-stat-link { text-decoration: none; }

.hero-stat-link:hover,
.hero-stat-link:focus-visible {
  background: var(--color-surface);
  border-color: var(--color-primary);
  box-shadow: var(--soft-shadow);
  transform: translateY(-1px);
}

.hero-stat-link:focus-visible {
  outline: 2px solid var(--color-primary);
  outline-offset: 2px;
}

.hero-stat span {
  display: block;
  font-family: var(--font-mono);
  font-size: 1.6rem;
  color: var(--color-text);
  font-weight: 500;
}

.hero-stat label {
  display: block;
  margin-top: var(--space-1);
  color: var(--color-text-light);
  font-size: 0.82rem;
}

/* ─────────────────────────────────────────────────────────────────────────
   Leaderboard panel + entries
   ───────────────────────────────────────────────────────────────────────── */

.leaderboard-panel,
.error-panel,
.loading-panel {
  padding: var(--space-6);
}

.panel-header {
  display: flex;
  align-items: end;
  justify-content: space-between;
  gap: var(--space-4);
  margin-bottom: var(--space-5);
}

.panel-header h2 {
  font-size: 1.6rem;
}

.panel-note {
  max-width: 28ch;
  color: var(--color-text-light);
  font-size: 0.88rem;
  text-align: right;
}

.entry-list {
  display: grid;
  gap: var(--space-3);
}

.entry {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  overflow: hidden;
  transition:
    border-color var(--transition-fast),
    box-shadow var(--transition-fast),
    transform var(--transition-fast);
}

.entry:hover {
  border-color: var(--color-primary-light);
  box-shadow: var(--soft-shadow);
}

.entry summary {
  display: grid;
  grid-template-columns: 60px minmax(0, 1fr) auto 24px;
  align-items: center;
  gap: var(--space-4);
  padding: var(--space-5);
  cursor: pointer;
  list-style: none;
  transition: background-color 140ms ease;
}

.entry summary::-webkit-details-marker { display: none; }

.entry summary:focus-visible {
  outline: 2px solid var(--color-primary);
  outline-offset: -2px;
}

.entry[open] summary { border-bottom: 1px solid var(--color-border); }

.entry-rank {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-width: 44px;
  padding: 0.35rem 0.85rem;
  border-radius: var(--radius-pill);
  background: var(--color-primary);
  color: var(--color-text-contrast);
  font-family: var(--font-mono);
  font-size: 0.95rem;
  font-weight: 600;
}

.entry-model-name {
  display: block;
  font-size: 1.05rem;
  font-weight: 600;
  color: var(--color-text);
}

.entry-model-meta {
  display: block;
  margin-top: 3px;
  color: var(--color-text-light);
  font-size: 0.83rem;
}

.entry-score {
  font-family: var(--font-mono);
  color: var(--color-text);
  font-size: 0.95rem;
  font-weight: 500;
  text-align: right;
}

.entry-body {
  display: grid;
  grid-template-columns: minmax(0, 1.4fr) minmax(260px, 0.8fr);
  gap: var(--space-6);
  padding: var(--space-6);
}

/* ─────────────────────────────────────────────────────────────────────────
   Problem grid + theorem cards
   ───────────────────────────────────────────────────────────────────────── */

.problem-grid {
  display: grid;
  gap: var(--space-3);
  margin-top: var(--space-3);
}

.problem-item {
  position: relative;
  display: grid;
  gap: var(--space-3);
  padding: var(--space-4) var(--space-5);
  background: var(--color-surface-soft);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
}

.problem-title-link {
  color: var(--color-text);
  font-size: 0.94rem;
  font-weight: 500;
  text-decoration: none;
}

.problem-title-link:hover { color: var(--color-primary); }

.problem-title-link:focus-visible {
  outline: 2px solid var(--color-primary);
  outline-offset: 2px;
  color: var(--color-primary);
  border-radius: var(--radius-sm);
}

.problem-meta-row {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  flex-wrap: wrap;
}

.problem-meta {
  color: var(--color-text-light);
  font-family: var(--font-mono);
  font-size: 0.76rem;
}

.production-note {
  border-top: 1px solid var(--color-border);
  padding-top: var(--space-2);
  font-size: 0.82rem;
  color: var(--color-text-light);
}

.production-note > summary {
  cursor: pointer;
  color: var(--color-primary);
  font-family: var(--font-mono);
  font-size: 0.74rem;
  letter-spacing: 0.04em;
  text-transform: uppercase;
}

.production-note > summary:hover { color: var(--color-primary-focus); }

.production-note > p {
  margin: var(--space-2) 0 0;
  white-space: pre-wrap;
  line-height: 1.45;
}

.problem-id-wrap {
  position: relative;
  display: inline-flex;
}

.problem-id-trigger,
.problem-proof-link {
  display: inline-flex;
  align-items: center;
  min-height: 28px;
  padding: 0 0.7rem;
  border-radius: var(--radius-pill);
  background: rgba(56, 110, 224, 0.08);
  border: 1px solid rgba(56, 110, 224, 0.20);
  color: var(--color-primary);
  font-family: var(--font-mono);
  font-size: 0.76rem;
  text-decoration: none;
  transition:
    background-color var(--transition-fast),
    border-color var(--transition-fast),
    color var(--transition-fast);
}

.dark-theme .problem-id-trigger,
.dark-theme .problem-proof-link {
  background: rgba(59, 148, 255, 0.10);
  border-color: rgba(59, 148, 255, 0.28);
}

.problem-id-trigger { cursor: default; }

.problem-proof-link:hover {
  color: var(--color-text-contrast);
  background: var(--color-primary);
  border-color: var(--color-primary);
}

.problem-proof-link:focus-visible {
  outline: 2px solid var(--color-primary);
  outline-offset: 2px;
}

/* Theorem-statement popover, anchored to the problem-id pill */
.theorem-card {
  display: none;
  position: absolute;
  top: calc(100% + 8px);
  left: 0;
  width: min(760px, calc(100vw - 120px));
  padding: var(--space-4);
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  box-shadow: var(--long-shadow);
  z-index: 8;
  pointer-events: none;
}

.problem-id-wrap:hover .theorem-card,
.problem-id-wrap:focus-within .theorem-card {
  display: block;
}

.theorem-card pre {
  margin-top: var(--space-2);
  white-space: pre-wrap;
  overflow-wrap: anywhere;
  font-family: var(--font-mono);
  font-size: 0.8rem;
  color: var(--color-text);
}

/* Stack multi-hole anchor blocks with a small gap. Used both inside the
   popover (`.theorem-card .hole`) and on the problems page, where each
   `@[eval_problem]`-annotated declaration tied to a manifest entry is
   rendered as its own highlighted block. */
.hole + .hole {
  margin-top: 0.75rem;
}

.theorem-card-rendered .hl.lean.block {
  margin: var(--space-2) 0 0;
  padding: var(--space-4);
  border-radius: var(--radius-md);
  box-shadow: none;
}

.theorem-card-static {
  display: block;
  position: static;
  margin-top: var(--space-4);
  box-shadow: none;
}

/* ─────────────────────────────────────────────────────────────────────────
   Per-entry stats column
   ───────────────────────────────────────────────────────────────────────── */

.entry-side {
  border-left: 1px solid var(--color-border);
  padding-left: var(--space-6);
}

.stat-pair {
  display: flex;
  justify-content: space-between;
  gap: var(--space-3);
  padding: var(--space-2) 0;
  color: var(--color-text-light);
  font-size: 0.9rem;
  border-bottom: 1px solid var(--color-border);
}

.stat-pair-link {
  text-decoration: none;
  color: inherit;
  transition: color var(--transition-fast);
}

.stat-pair-link:hover,
.stat-pair-link:focus-visible {
  color: var(--color-primary);
}

.stat-pair-link:focus-visible {
  outline: 2px solid var(--color-primary);
  outline-offset: 2px;
}

.submitter-list {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-2);
  margin-top: var(--space-3);
}

.submitter-chip {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  padding: 0.4rem 0.7rem;
  border-radius: var(--radius-pill);
  background: var(--color-surface-soft);
  border: 1px solid var(--color-border);
  color: var(--color-text);
  font-size: 0.82rem;
}

.submitter-chip span span { color: var(--color-primary); }

.empty-state,
.error-detail,
.empty-inline {
  color: var(--color-text-light);
}

/* Empty showcase (when there are no entries yet) */
.empty-showcase {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(320px, 0.9fr);
  gap: var(--space-6);
  padding-top: var(--space-2);
}

.empty-problem-list {
  display: grid;
  gap: var(--space-3);
}

.empty-problem {
  display: grid;
  gap: var(--space-3);
  padding: var(--space-4) var(--space-5);
  background: var(--color-surface-soft);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
}

/* ─────────────────────────────────────────────────────────────────────────
   Verso .hl.lean.block — code blocks (Lean syntax highlighted)
   ───────────────────────────────────────────────────────────────────────── */

.page-copy .hl.lean.block,
.theorem-card .hl.lean.block,
.theorem-card-rendered .hl.lean.block {
  margin: var(--space-4) 0 var(--space-6);
  padding: var(--space-5);
  background: var(--color-surface-soft);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  box-shadow: none;
  overflow-x: auto;
  font-family: var(--font-mono);
  font-size: 0.92rem;
  color: var(--color-text);
  line-height: 1.55;
}

.hl.lean.block code { color: inherit; }

.hl.lean.block .inter-text,
.hl.lean.block .unknown.token { color: var(--tok-default); }

.hl.lean.block .keyword.token {
  color: var(--tok-keyword);
  font-weight: 700;
}

.hl.lean.block .const.token,
.hl.lean.block .sort.token { color: var(--tok-const); }

.hl.lean.block .var.token,
.hl.lean.block .typed.token { color: var(--tok-var); }

.hl.lean.block .tactic { color: var(--color-text-light); }

.hl.lean.block .tactic-state { margin-left: 8px; }

.page-copy .prose .verso-message.warning {
  color: #181c20;
}

.page-copy .hl.lean.block + h2 { margin-top: var(--space-8); }

/* ─────────────────────────────────────────────────────────────────────────
   Catalog (problems index page)
   ───────────────────────────────────────────────────────────────────────── */

.catalog-panel { margin-top: 0; }

.catalog-columns {
  display: grid;
  gap: var(--space-8);
}

.catalog-grid {
  display: grid;
  gap: var(--space-4);
  margin-top: var(--space-3);
}

.catalog-item {
  padding: var(--space-5);
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  transition:
    border-color var(--transition-fast),
    box-shadow var(--transition-fast);
}

.catalog-item:hover {
  border-color: var(--color-primary-light);
  box-shadow: var(--soft-shadow);
}

.catalog-item-head {
  display: flex;
  align-items: start;
  justify-content: space-between;
  gap: var(--space-4);
}

.catalog-item-head h3 {
  margin-top: var(--space-2);
  font-family: var(--font-primary);
  font-size: 1.05rem;
  font-weight: 600;
  color: var(--color-text);
}

.catalog-item code {
  font-family: var(--font-mono);
  font-size: 0.76rem;
  color: var(--color-primary);
}

.catalog-notes { margin-top: var(--space-3); }

/* ─────────────────────────────────────────────────────────────────────────
   Responsive
   ───────────────────────────────────────────────────────────────────────── */

/* Suppress Verso's `sorry` warning underline + tooltip on theorem cards
   and the problems page. Problem statements are deliberate placeholders;
   the warning treatment is noise. */
.verso-message.warning,
.has-info.warning > .hover-info {
  display: none;
}

.has-info.warning {
  text-decoration: none;
  background: transparent;
}

/* Problems-page live filter box. */
.problems-filter {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: var(--space-3);
  margin: 0 0 var(--space-4);
  padding: var(--space-3) var(--space-4);
  border-radius: var(--radius-md);
  border: 1px solid var(--color-border);
  background: var(--color-surface-soft);
}

.problems-filter-label {
  display: inline-flex;
  align-items: baseline;
  gap: var(--space-2);
  color: var(--color-text);
  font-weight: 500;
  font-size: 0.92rem;
  white-space: nowrap;
}

.problems-filter-icon {
  color: var(--color-primary);
  font-size: 1.05rem;
}

.problems-filter-label-text {
  font-family: inherit;
}

/* The hidden filter haystack span carries the searchable text as a
   `data-filter-text` attribute. Keep it out of the layout entirely. */
.problem-filter-haystack {
  display: none !important;
}

.problems-filter-input {
  flex: 1 1 auto;
  min-width: 0;
  padding: var(--space-2) var(--space-3);
  border-radius: var(--radius-md);
  border: 1px solid var(--color-border);
  background: var(--color-surface);
  color: var(--color-text);
  font-family: inherit;
  font-size: 0.95rem;
}

.problems-filter-input:focus-visible {
  outline: 2px solid var(--color-primary);
  outline-offset: 2px;
  border-color: var(--color-primary);
}

.problems-filter-count {
  color: var(--color-text-light);
  font-size: 0.85rem;
  font-family: var(--font-mono);
}

/* Group section message when all child problem sections are filtered out. */
main section.group-empty > h2::after {
  content: " — (all hidden by filter)";
  color: var(--color-text-light);
  font-weight: 400;
  font-size: 0.85em;
}


@media (max-width: 1023px) {
  .topbar-inner,
  .panel-header,
  .entry-body,
  .hero-grid,
  .empty-showcase {
    grid-template-columns: 1fr;
    display: grid;
  }

  .panel-note,
  .entry-score { text-align: left; }

  .entry-score-line {
    justify-content: flex-start;
  }

  .prose ul,
  .prose ol { padding-left: 1.15rem; }

  .entry summary {
    grid-template-columns: 60px minmax(0, 1fr);
  }

  .entry-score { grid-column: 2; }

  .entry summary::after {
    grid-column: 3;
    grid-row: 1;
  }

  .entry-side {
    border-left: 0;
    border-top: 1px solid var(--color-border);
    padding-left: 0;
    padding-top: var(--space-5);
  }

  .hero-side {
    border-left: 0;
    border-top: 1px solid var(--color-border);
    padding-left: 0;
    padding-top: var(--space-5);
  }

  nav.top ol { gap: var(--space-2); }

  .theorem-card { width: min(520px, calc(100vw - 64px)); }

  .wordmark-text { display: none; }

  .page-copy { padding: var(--space-5) var(--space-5); }
}

/* Home page: hide the auto-generated <article><h1> title — the hero
   panel renders its own styled <h1> in the right place. */
.home-page article > h1 { display: none; }

/* ─────────────────────────────────────────────────────────────────────────
   Components introduced after the initial reskin (coverage matrix, score
   pills, problem-detail TOC, submit CTA, two-row footer, hole separator,
   etc.). All retinted to the lean-lang.org token palette.
   ───────────────────────────────────────────────────────────────────────── */

/* Hide Verso's tactic-state toggle/panel — irrelevant on a read-only catalog. */
input.tactic-toggle,
.tactic-state {
  display: none;
}

/* Score pills in the leaderboard summary row. */
.entry-score-line {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  flex-wrap: wrap;
  justify-content: flex-end;
}

.entry-score-primary {
  color: var(--color-text);
  font-family: var(--font-mono);
  font-size: 1rem;
  font-weight: 600;
}

.entry-score-pill {
  display: inline-flex;
  align-items: center;
  padding: 2px 9px;
  border-radius: var(--radius-pill);
  font-family: var(--font-mono);
  font-size: 0.74rem;
  border: 1px solid transparent;
}

.entry-score-pill--main {
  color: var(--color-primary);
  border-color: rgba(56, 110, 224, 0.28);
  background: rgba(56, 110, 224, 0.08);
}

.entry-score-pill--test {
  color: #7c4dcc;
  border-color: rgba(124, 77, 204, 0.28);
  background: rgba(124, 77, 204, 0.08);
}

.dark-theme .entry-score-pill--main {
  color: var(--color-primary);
  border-color: rgba(59, 148, 255, 0.32);
  background: rgba(59, 148, 255, 0.10);
}

.dark-theme .entry-score-pill--test {
  color: #c5a5ff;
  border-color: rgba(197, 165, 255, 0.32);
  background: rgba(197, 165, 255, 0.10);
}

/* Hero stat strip: pill-shaped inline strip wrapping the home-page stats. */
.hero-stat-strip {
  display: inline-flex;
  flex-wrap: wrap;
  gap: 0;
  margin-top: var(--space-5);
  border-radius: var(--radius-pill);
  border: 1px solid var(--color-border);
  background: var(--color-surface-soft);
  overflow: hidden;
}

.hero-stat-strip .hero-stat,
.hero-stat-strip .hero-stat-link {
  border: 0;
  border-right: 1px solid var(--color-border);
  border-radius: 0;
  background: transparent;
  padding: 8px 18px;
  min-width: 0;
  display: inline-flex;
  align-items: baseline;
  gap: var(--space-2);
}

.hero-stat-strip > :last-child { border-right: 0; }

.hero-stat-strip .hero-stat span {
  font-size: 1.05rem;
  display: inline;
}

.hero-stat-strip .hero-stat label {
  display: inline;
  margin-top: 0;
  font-size: 0.78rem;
  color: var(--color-text-light);
}

/* Footer rows. */
.footer-row {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: var(--space-4);
}

.footer-row a {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
}

.footer-row a:focus-visible {
  outline: 2px solid var(--color-primary);
  outline-offset: 2px;
  border-radius: var(--radius-sm);
}

.footer-row svg {
  width: 14px;
  height: 14px;
  flex-shrink: 0;
}

.footer-row--community {
  border-top: 1px solid var(--color-border);
  padding-top: var(--space-3);
  font-size: 0.84rem;
  color: var(--color-text-light);
}

/* Submit-page CTA button — uses the lean-lang.org filled-primary recipe. */
.cta-button {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  margin: var(--space-2) 0 var(--space-6);
  padding: 14px 22px;
  border-radius: var(--radius-md);
  background: var(--color-primary);
  color: var(--color-text-contrast);
  font-family: var(--font-primary);
  font-size: 1rem;
  font-weight: 600;
  text-decoration: none;
  box-shadow: var(--soft-shadow);
  transition: transform var(--transition-fast), box-shadow var(--transition-fast), background-color var(--transition-fast);
}

.cta-button:hover,
.cta-button:focus-visible {
  background: var(--color-primary-focus);
  transform: translateY(-1px);
  box-shadow: var(--long-shadow);
}

.cta-button:focus-visible {
  outline: 2px solid var(--color-primary);
  outline-offset: 3px;
}

/* Submit-page TL;DR callout. */
.submit-tldr {
  margin: var(--space-1) 0 var(--space-5);
  padding: var(--space-4) var(--space-5);
  border-radius: var(--radius-md);
  border: 1px solid var(--color-border);
  background: var(--color-surface-soft);
  color: var(--color-text);
  font-size: 0.95rem;
}

/* Coverage matrix (rows = problems, cols = models). */
.coverage-panel {
  border: 1px solid var(--color-border);
  background: var(--color-surface);
  border-radius: var(--radius-lg);
  padding: var(--space-6);
  margin-top: var(--space-5);
  box-shadow: var(--soft-shadow);
}

.coverage-table-wrap {
  overflow-x: auto;
  margin-top: var(--space-3);
  border-radius: var(--radius-md);
  border: 1px solid var(--color-border);
}

.coverage-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.86rem;
}

.coverage-table th,
.coverage-table td {
  padding: var(--space-2) var(--space-3);
  border-bottom: 1px solid var(--color-border);
  text-align: left;
  vertical-align: middle;
}

.coverage-table thead th {
  position: sticky;
  top: 0;
  background: var(--color-surface-soft);
  color: var(--color-text-light);
  font-weight: 600;
  font-size: 0.78rem;
  letter-spacing: 0.04em;
  text-transform: uppercase;
}

.coverage-table tbody tr:hover {
  background: var(--color-hover);
}

.coverage-row-link {
  color: var(--color-text);
  text-decoration: none;
}

.coverage-row-link:hover,
.coverage-row-link:focus-visible {
  color: var(--color-primary);
}

.coverage-cell {
  text-align: center;
  font-family: var(--font-mono);
  width: 60px;
}

.coverage-cell--solved   { color: var(--color-primary); font-weight: 600; }
.coverage-cell--unsolved { color: var(--color-border-light); }

.coverage-kind {
  display: inline-block;
  padding: 1px 7px;
  border-radius: var(--radius-pill);
  font-family: var(--font-mono);
  font-size: 0.7rem;
  margin-left: var(--space-2);
}

.coverage-kind--main {
  color: var(--color-primary);
  background: rgba(56, 110, 224, 0.08);
}

.coverage-kind--test {
  color: #7c4dcc;
  background: rgba(124, 77, 204, 0.08);
}

.dark-theme .coverage-kind--main {
  color: var(--color-primary);
  background: rgba(59, 148, 255, 0.10);
}

.dark-theme .coverage-kind--test {
  color: #c5a5ff;
  background: rgba(197, 165, 255, 0.10);
}

/* Per-problem-detail page TOC. */
.problems-toc {
  margin-top: var(--space-5);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  background: var(--color-surface);
}

.problems-toc > summary {
  cursor: pointer;
  padding: var(--space-3) var(--space-4);
  list-style: none;
  font-family: var(--font-primary);
  font-weight: 600;
  color: var(--color-text);
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.problems-toc > summary::-webkit-details-marker { display: none; }

.problems-toc > summary::after {
  content: "▾";
  color: var(--color-primary);
  font-size: 0.85rem;
  transition: transform 160ms ease;
}

.problems-toc[open] > summary::after { transform: rotate(180deg); }

.problems-toc-list {
  list-style: none;
  margin: 0;
  padding: var(--space-1) var(--space-4) var(--space-4);
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
  gap: 4px var(--space-4);
  max-height: 360px;
  overflow-y: auto;
}

.problems-toc-list li { font-size: 0.88rem; }

.problems-toc-list a {
  color: var(--color-text-light);
  text-decoration: none;
  display: inline-block;
  padding: 4px 0;
}

.problems-toc-list a:hover,
.problems-toc-list a:focus-visible {
  color: var(--color-primary);
}

/* Mobile fallback for the Submit CTA. */
@media (max-width: 900px) {
  .cta-button {
    display: flex;
    width: 100%;
    justify-content: center;
  }
}