/* chimpmemory.com — design system
   Sans-first, light/dark aware. Mono is reserved for numerals (tile numbers,
   the number-memory digit display, scores) so the "data" in each game reads
   distinctly from the surrounding prose. Zero external font/asset requests. */

:root {
  --bg: #f4f6f3;
  --bg-raised: #ffffff;
  --bg-inset: #eef1ec;
  --border: #d7ddd4;
  --border-soft: #e6e9e3;
  --text: #12201c;
  --text-dim: #4d5c56;
  --text-faint: #8a978f;
  --accent: #178a67;
  --accent-dim: #0f6e51;
  --accent-contrast: #f2fff9;
  --flash: #c9821b;
  --flash-contrast: #241300;
  --danger: #d94433;
  --focus: #0a6cbf;
  --radius: 10px;
  --radius-sm: 6px;
  --sans: ui-sans-serif, "Segoe UI", "Helvetica Neue", Helvetica, Arial, system-ui,
    -apple-system, Roboto, sans-serif;
  --mono: ui-monospace, "SF Mono", "Cascadia Mono", Menlo, Consolas,
    "Liberation Mono", monospace;
  --maxw: 1080px;
}

:root[data-theme="dark"] {
  --bg: #0d1210;
  --bg-raised: #161c19;
  --bg-inset: #0a0e0c;
  --border: #232b27;
  --border-soft: #1a201d;
  --text: #eef1ee;
  --text-dim: #9fb0a8;
  --text-faint: #5f6f68;
  --accent: #35d6a8;
  --accent-dim: #1f9c78;
  --accent-contrast: #052018;
  --flash: #f2a93b;
  --flash-contrast: #241300;
  --danger: #ff6b5e;
  --focus: #7cc6ff;
}

@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --bg: #0d1210;
    --bg-raised: #161c19;
    --bg-inset: #0a0e0c;
    --border: #232b27;
    --border-soft: #1a201d;
    --text: #eef1ee;
    --text-dim: #9fb0a8;
    --text-faint: #5f6f68;
    --accent: #35d6a8;
    --accent-dim: #1f9c78;
    --accent-contrast: #052018;
    --flash: #f2a93b;
    --flash-contrast: #241300;
    --danger: #ff6b5e;
    --focus: #7cc6ff;
  }
}

* { box-sizing: border-box; }
html { color-scheme: light dark; }

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: var(--sans);
  font-size: 16px;
  line-height: 1.5;
  -webkit-font-smoothing: antialiased;
}

a { color: var(--accent-dim); text-decoration: none; }
:root[data-theme="dark"] a { color: var(--accent); }
@media (prefers-color-scheme: dark) { :root:not([data-theme="light"]) a { color: var(--accent); } }
a:hover { text-decoration: underline; }

.skip-link {
  position: absolute;
  left: -9999px;
  top: 0;
  background: var(--accent);
  color: var(--accent-contrast);
  padding: 8px 12px;
  z-index: 100;
}
.skip-link:focus { left: 8px; top: 8px; }

button, select, input, textarea {
  font-family: inherit;
  font-size: inherit;
  color: inherit;
}

button {
  cursor: pointer;
  background: var(--bg-inset);
  border: 1px solid var(--border);
  color: var(--text);
  border-radius: var(--radius-sm);
  padding: 9px 16px;
  font-weight: 600;
  transition: border-color .12s ease, background .12s ease, color .12s ease, transform .08s ease;
}
button:hover { border-color: var(--accent-dim); color: var(--accent-dim); }
:root[data-theme="dark"] button:hover { color: var(--accent); }
button:active { transform: translateY(1px); }
button:focus-visible, a:focus-visible, input:focus-visible {
  outline: 2px solid var(--focus);
  outline-offset: 2px;
}
button.primary {
  background: var(--accent);
  border-color: var(--accent);
  color: var(--accent-contrast);
}
button.primary:hover { color: var(--accent-contrast); filter: brightness(1.06); }
button:disabled { opacity: .5; cursor: not-allowed; }
button.icon-btn { padding: 6px 10px; font-size: 13px; font-weight: 500; }

input[type="text"] {
  background: var(--bg-inset);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  padding: 10px 12px;
  font-family: var(--mono);
  font-size: 20px;
  letter-spacing: .04em;
}

/* ---------- layout shell ---------- */
.site-header {
  border-bottom: 1px solid var(--border-soft);
  position: sticky;
  top: 0;
  background: color-mix(in srgb, var(--bg) 90%, transparent);
  backdrop-filter: blur(8px);
  z-index: 20;
}
.header-inner {
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 14px 20px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
}
.brand { display: flex; align-items: center; gap: 9px; }
.brand-icon { width: 26px; height: 26px; display: block; flex-shrink: 0; }
.brand-name {
  font-weight: 800;
  font-size: 18px;
  letter-spacing: -0.02em;
  color: var(--text);
}
.brand-name .brand-accent { color: var(--accent-dim); }
:root[data-theme="dark"] .brand-name .brand-accent { color: var(--accent); }
@media (prefers-color-scheme: dark) { :root:not([data-theme="light"]) .brand-name .brand-accent { color: var(--accent); } }

.header-actions { display: flex; align-items: center; gap: 8px; }

main { max-width: var(--maxw); margin: 0 auto; padding: 0 20px 60px; }

.container-narrow { max-width: 720px; margin: 0 auto; padding: 40px 20px 60px; }
.container-narrow h1 { font-size: 24px; }
.container-narrow h2 { font-size: 17px; margin-top: 32px; }
.container-narrow p, .container-narrow li { color: var(--text-dim); }

.faq-item { margin-bottom: 18px; }
.faq-item h3 { font-size: 15px; margin: 0 0 6px; }
.faq-item p { margin: 0; color: var(--text-dim); }

/* ---------- hero ---------- */
.hero { padding: 36px 0 30px; }
.hero-inner {
  display: grid;
  grid-template-columns: 1fr;
  gap: 28px;
  align-items: center;
}
@media (min-width: 760px) {
  .hero-inner { grid-template-columns: 1.2fr 0.8fr; }
}
.hero h1 {
  font-size: clamp(28px, 4.4vw, 42px);
  margin: 0 0 12px;
  letter-spacing: -0.02em;
  line-height: 1.08;
}
.hero p { color: var(--text-dim); margin: 0 0 8px; font-size: 15.5px; max-width: 46ch; }
.hero .trust-line {
  margin-top: 14px;
  font-size: 12.5px;
  color: var(--text-faint);
}
.hero .trust-line .dot { color: var(--accent-dim); margin: 0 8px; }
:root[data-theme="dark"] .hero .trust-line .dot { color: var(--accent); }
@media (prefers-color-scheme: dark) { :root:not([data-theme="light"]) .hero .trust-line .dot { color: var(--accent); } }

/* ---- hero ghost-grid: ambient demo of the chimp test's signature "vanish" ---- */
.hero-demo { display: flex; justify-content: center; }
.ghost-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 10px;
  width: min(260px, 100%);
  aspect-ratio: 1;
}
.ghost-tile {
  background: var(--bg-inset);
  border: 1px solid var(--border-soft);
  border-radius: 10px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-family: var(--mono);
  font-weight: 700;
  font-size: 20px;
  color: var(--text);
  animation: ghost-cycle 3.6s ease-in-out infinite;
  animation-delay: var(--d, 0s);
}
@keyframes ghost-cycle {
  0%, 8% { background: var(--flash); color: var(--flash-contrast); border-color: var(--flash); }
  22%, 100% { background: var(--bg-inset); color: transparent; border-color: var(--border-soft); }
}
@media (prefers-reduced-motion: reduce) {
  .ghost-tile { animation: none; background: var(--bg-inset); color: transparent; }
}

/* ---------- tabs ---------- */
.tabbar {
  display: flex;
  gap: 4px;
  border-bottom: 1px solid var(--border-soft);
  margin-bottom: 22px;
  overflow-x: auto;
}
.tabbar.solo-tabbar { margin-top: 16px; }
.tab-btn {
  display: inline-block;
  background: transparent;
  border: none;
  border-bottom: 2px solid transparent;
  border-radius: 0;
  padding: 10px 4px;
  margin-right: 26px;
  color: var(--text-dim);
  font-size: 15px;
  font-weight: 700;
  white-space: nowrap;
  text-decoration: none;
}
.tab-btn:hover { color: var(--text); border-color: var(--border); text-decoration: none; }
.tab-btn[aria-selected="true"], .tab-btn.active { color: var(--accent-dim); border-color: var(--accent-dim); }
:root[data-theme="dark"] .tab-btn[aria-selected="true"], :root[data-theme="dark"] .tab-btn.active { color: var(--accent); border-color: var(--accent); }
@media (prefers-color-scheme: dark) { :root:not([data-theme="light"]) .tab-btn[aria-selected="true"], :root:not([data-theme="light"]) .tab-btn.active { color: var(--accent); border-color: var(--accent); } }
.tab-panel { display: none; }
.tab-panel.active { display: block; }

/* ---------- game layout ---------- */
.game-wrap { display: grid; grid-template-columns: 1fr; gap: 20px; max-width: 640px; margin: 0 auto; }

.panel {
  background: var(--bg-raised);
  border: 1px solid var(--border-soft);
  border-radius: var(--radius);
  padding: 20px;
}
.panel + .panel { margin-top: 18px; }

.game-status {
  display: flex;
  gap: 24px;
  margin-bottom: 14px;
}
.status-item { display: flex; flex-direction: column; gap: 2px; }
.status-label {
  font-size: 11px;
  text-transform: uppercase;
  letter-spacing: .08em;
  color: var(--text-faint);
}
.status-value { font-family: var(--mono); font-size: 22px; font-weight: 700; }

.game-instructions { color: var(--text-dim); font-size: 14.5px; margin: 0 0 16px; min-height: 1.5em; }

.game-controls { margin-top: 16px; text-align: center; }
.game-controls .primary { padding: 11px 28px; font-size: 15px; }

/* ---------- chimp test board ---------- */
.chimp-board {
  display: grid;
  grid-template-columns: repeat(var(--cols, 5), 1fr);
  grid-template-rows: repeat(var(--rows, 5), 1fr);
  gap: 8px;
  aspect-ratio: 1;
  width: 100%;
}
.board-cell { min-width: 0; min-height: 0; }
button.board-cell.tile {
  background: var(--flash);
  color: var(--flash-contrast);
  border: none;
  border-radius: 8px;
  font-family: var(--mono);
  font-weight: 700;
  font-size: clamp(12px, 3.4vw, 20px);
  display: flex;
  align-items: center;
  justify-content: center;
  transition: transform .1s ease, background .15s ease;
}
button.board-cell.tile:hover { transform: scale(1.04); }
button.board-cell.tile.blank { background: var(--bg-inset); border: 1px solid var(--border); }
button.board-cell.tile.correct-flash { animation: pulse-ok .3s ease; }
button.board-cell.tile.wrong-flash { background: var(--danger); color: #fff; }
@keyframes pulse-ok {
  0% { transform: scale(1); }
  50% { transform: scale(1.12); }
  100% { transform: scale(1); }
}

/* ---------- sequence memory board ---------- */
.seq-board {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 10px;
  aspect-ratio: 1;
  width: 100%;
  max-width: 360px;
  margin: 0 auto;
}
.seq-tile {
  background: var(--bg-inset);
  border: 1px solid var(--border);
  border-radius: 12px;
  transition: background .12s ease, transform .1s ease;
}
.seq-tile.lit { background: var(--flash); border-color: var(--flash); transform: scale(1.03); }
.seq-tile.picked { background: var(--accent); border-color: var(--accent); }
.seq-tile.wrong { background: var(--danger); border-color: var(--danger); }

/* ---------- number memory ---------- */
.number-stage { text-align: center; padding: 20px 0 8px; }
.number-display {
  font-family: var(--mono);
  font-size: clamp(30px, 8vw, 52px);
  font-weight: 700;
  letter-spacing: .06em;
  min-height: 1.3em;
  color: var(--text);
}
.number-display.hidden-number { color: var(--text-faint); }
.answer-field { margin-top: 18px; display: flex; gap: 10px; justify-content: center; flex-wrap: wrap; }
.answer-field input { text-align: center; width: 220px; }

/* ---------- visual memory board ---------- */
.visual-board {
  display: grid;
  grid-template-columns: repeat(var(--cols, 3), 1fr);
  grid-template-rows: repeat(var(--rows, 3), 1fr);
  gap: 8px;
  aspect-ratio: 1;
  width: 100%;
  max-width: 440px;
  margin: 0 auto;
}
.visual-cell {
  min-width: 0;
  min-height: 0;
  background: var(--bg-inset);
  border: 1px solid var(--border);
  border-radius: 8px;
  transition: background .12s ease, transform .1s ease, box-shadow .12s ease;
}
.visual-cell:hover { transform: scale(1.03); }
.visual-cell.flash {
  background: #f7fbff;
  border-color: #ffffff;
  box-shadow: 0 0 0 2px var(--accent-dim), 0 0 14px 1px rgba(255, 255, 255, .35);
}
.visual-cell.correct { background: var(--accent); border-color: var(--accent); }
.visual-cell.wrong { background: var(--danger); border-color: var(--danger); }
.visual-cell.missed {
  background: var(--bg-inset);
  border-color: var(--accent-dim);
  box-shadow: inset 0 0 0 2px var(--accent-dim);
}

/* ---------- verbal memory ---------- */
.verbal-stage { text-align: center; padding: 24px 0 8px; }
.verbal-word {
  font-size: clamp(28px, 7vw, 46px);
  font-weight: 800;
  letter-spacing: -0.01em;
  min-height: 1.3em;
  color: var(--text);
  transition: color .12s ease;
}
.verbal-word.verbal-correct { color: var(--accent-dim); }
:root[data-theme="dark"] .verbal-word.verbal-correct { color: var(--accent); }
@media (prefers-color-scheme: dark) { :root:not([data-theme="light"]) .verbal-word.verbal-correct { color: var(--accent); } }
.verbal-word.verbal-wrong { color: var(--danger); }
.verbal-controls { margin-top: 22px; display: flex; gap: 12px; justify-content: center; flex-wrap: wrap; }
.verbal-controls button { padding: 12px 32px; font-size: 15px; min-width: 120px; }

/* ---------- results ---------- */
.results-panel h2 { margin-top: 0; font-size: 18px; }
.score-line { font-size: 16px; }
.score-line strong { font-family: var(--mono); font-size: 20px; }
.tier-line {
  display: inline-block;
  background: var(--bg-inset);
  border: 1px solid var(--border-soft);
  border-radius: 999px;
  padding: 6px 14px;
  font-size: 13px;
  font-weight: 600;
  color: var(--accent-dim);
  margin: 4px 0 18px;
}
:root[data-theme="dark"] .tier-line { color: var(--accent); }
@media (prefers-color-scheme: dark) { :root:not([data-theme="light"]) .tier-line { color: var(--accent); } }

.history { margin-top: 22px; }
.history h3 {
  font-size: 11px;
  text-transform: uppercase;
  letter-spacing: .08em;
  color: var(--text-faint);
  margin: 0 0 10px;
}
.history-list { list-style: none; margin: 0; padding: 0; display: flex; flex-direction: column; gap: 6px; }
.history-list li {
  display: flex;
  justify-content: space-between;
  gap: 12px;
  padding: 8px 12px;
  background: var(--bg-inset);
  border: 1px solid var(--border-soft);
  border-radius: 8px;
  font-size: 13.5px;
}
.history-score { font-family: var(--mono); font-weight: 700; }
.history-date { color: var(--text-faint); }
.history-empty { color: var(--text-faint); justify-content: flex-start !important; }

/* ---------- about section ---------- */
.about-section { padding-top: 10px; }
.about-section h2 { font-size: 18px; margin-top: 30px; }
.about-section p { color: var(--text-dim); max-width: 68ch; }

/* ---------- dedicated single-test pages ---------- */
.solo-head { max-width: 640px; margin: 30px auto 22px; text-align: center; }
.solo-head h1 { font-size: clamp(26px, 4vw, 36px); margin: 0 0 10px; letter-spacing: -0.02em; }
.solo-head .solo-intro { color: var(--text-dim); font-size: 15.5px; margin: 0 auto; max-width: 52ch; }
.solo-nav { max-width: 640px; margin: 30px auto 0; padding-top: 22px; border-top: 1px solid var(--border-soft); }
.solo-nav h2 { font-size: 13px; text-transform: uppercase; letter-spacing: .08em; color: var(--text-faint); margin: 0 0 10px; }
.test-links { list-style: none; padding: 0; margin: 8px 0 0; display: flex; flex-wrap: wrap; gap: 8px 18px; }
.test-links li { font-size: 14.5px; }

/* ---------- footer ---------- */
.site-footer {
  border-top: 1px solid var(--border-soft);
  margin-top: 40px;
}
.footer-inner {
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 24px 20px 40px;
  display: flex;
  flex-wrap: wrap;
  gap: 16px;
  justify-content: space-between;
  color: var(--text-faint);
  font-size: 12.5px;
}
.footer-links { display: flex; gap: 16px; flex-wrap: wrap; }
.footer-links a { color: var(--text-dim); }

/* ---------- misc ---------- */
.visually-hidden {
  position: absolute; width: 1px; height: 1px; padding: 0; margin: -1px;
  overflow: hidden; clip: rect(0,0,0,0); white-space: nowrap; border: 0;
}

::selection { background: var(--accent); color: var(--accent-contrast); }

::-webkit-scrollbar { width: 10px; height: 10px; }
::-webkit-scrollbar-track { background: var(--bg-inset); }
::-webkit-scrollbar-thumb { background: var(--border); border-radius: 6px; }
::-webkit-scrollbar-thumb:hover { background: var(--text-faint); }