/* === Kill site header offset === */
.arcade-header-bar,
.arcade-nav,
.nav-profile,
.profile-fab,
[data-theme-toggle],
.theme-toggle,
body > header,
.site-footer {
  display: none !important;
}
html, body {
  padding-top: 0 !important;
  padding-bottom: 0 !important;
  margin: 0 !important;
}
body.game-page,
body[data-type="game"] {
  padding-top: 0 !important;
  padding-bottom: 0 !important;
}

/* Am / Is / Are · T2T 2 Unit 1 */
:root {
  --ai-bg: #f0f4ff;
  --ai-card: #ffffff;
  --ai-text: #1e1b4b;
  --ai-muted: #64748b;
  --ai-primary: #4f46e5;
  --ai-primary-dark: #4338ca;
  --ai-am: #0891b2;
  --ai-is: #7c3aed;
  --ai-are: #db2777;
  --ai-ok: #16a34a;
  --ai-bad: #dc2626;
  --ai-shadow: 0 10px 28px rgba(30, 27, 75, 0.08);
  --ai-radius: 18px;
}
html[data-theme="dark"] {
  --ai-bg: #0f1220;
  --ai-card: #1a1f35;
  --ai-text: #f1f5f9;
  --ai-muted: #94a3b8;
  --ai-shadow: 0 10px 28px rgba(0, 0, 0, 0.35);
}

* { box-sizing: border-box; }
html, body {
  margin: 0;
  min-height: 100%;
  min-height: 100dvh;
  background: var(--ai-bg) !important;
  color: var(--ai-text);
  font-family: system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
  -webkit-font-smoothing: antialiased;
}
.arcade-header-bar, .arcade-nav, .site-footer, body > header {
  display: none !important;
}

.ai-game {
  max-width: 520px;
  margin: 0 auto;
  padding: 12px 14px 40px;
  min-height: 100dvh;
}
@media (min-width: 768px) {
  .ai-game {
    max-width: 660px;
    padding: 24px 28px 52px;
  }
}

/* Top bar */
.ai-top {
  display: flex;
  align-items: center;
  gap: 10px;
  margin-bottom: 10px;
  flex-wrap: wrap;
}
.ai-back {
  width: 40px;
  height: 40px;
  border-radius: 12px;
  display: grid;
  place-items: center;
  background: var(--ai-card);
  color: var(--ai-text);
  text-decoration: none;
  border: 1px solid rgba(79, 70, 229, 0.12);
  flex-shrink: 0;
  font-size: 1.1rem;
}
.ai-title {
  flex: 1;
  font-size: 0.9rem;
  font-weight: 700;
  color: var(--ai-muted);
  min-width: 0;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}
.ai-badge {
  font-size: 11px;
  font-weight: 800;
  padding: 4px 10px;
  border-radius: 999px;
  background: rgba(79, 70, 229, 0.12);
  color: var(--ai-primary);
}
.ai-stats {
  display: flex;
  gap: 6px;
  width: 100%;
}
.ai-stat {
  font-size: 0.75rem;
  font-weight: 700;
  padding: 4px 10px;
  border-radius: 999px;
  background: rgba(79, 70, 229, 0.1);
  color: var(--ai-primary);
}
.ai-progress {
  height: 5px;
  background: rgba(0,0,0,0.06);
  border-radius: 3px;
  margin-bottom: 16px;
  overflow: hidden;
}
.ai-progress-fill {
  height: 100%;
  background: linear-gradient(90deg, var(--ai-primary), #818cf8);
  width: 0%;
  transition: width 0.35s ease;
  border-radius: 3px;
}

/* Start */
.ai-start {
  text-align: center;
  padding-top: 16px;
}
.ai-hero {
  font-size: 2.8rem;
  line-height: 1;
  margin-bottom: 10px;
}
.ai-start h1 {
  font-size: 1.5rem;
  font-weight: 800;
  letter-spacing: -0.02em;
  margin-bottom: 6px;
}
.ai-sub {
  color: var(--ai-muted);
  font-size: 0.95rem;
  margin-bottom: 18px;
  line-height: 1.45;
}
.ai-rules {
  background: var(--ai-card);
  border-radius: var(--ai-radius);
  padding: 14px 16px;
  box-shadow: var(--ai-shadow);
  margin-bottom: 20px;
  text-align: left;
}
.ai-rule {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 8px 0;
  border-bottom: 1px solid rgba(0,0,0,0.05);
  font-size: 0.9rem;
}
.ai-rule:last-child { border-bottom: none; }
.ai-rule-chip {
  font-weight: 800;
  font-size: 0.85rem;
  padding: 6px 12px;
  border-radius: 10px;
  color: #fff;
  min-width: 56px;
  text-align: center;
}
.ai-rule-chip.am {
  background: #e2e8f0;
  color: #475569;
}
.ai-rule-chip.is {
  background: var(--ai-ok);
  color: #fff;
}
.ai-rule-chip.are { background: var(--ai-are); }
html[data-theme="dark"] .ai-rule-chip.am {
  background: #334155;
  color: #cbd5e1;
}

/* Buttons */
.ai-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 14px 28px;
  font-size: 1.05rem;
  font-weight: 700;
  border-radius: 14px;
  background: var(--ai-primary);
  color: #fff;
  border: none;
  cursor: pointer;
  box-shadow: 0 4px 14px rgba(79, 70, 229, 0.35);
  transition: transform 0.12s, background 0.15s;
  min-height: 52px;
  min-width: 150px;
  font-family: inherit;
}
.ai-btn:hover { background: var(--ai-primary-dark); transform: translateY(-1px); }
.ai-btn:active { transform: translateY(1px); }
.ai-btn:disabled { opacity: 0.55; pointer-events: none; }
.ai-btn.secondary {
  background: var(--ai-card);
  color: var(--ai-text);
  box-shadow: var(--ai-shadow);
  border: 1px solid rgba(0,0,0,0.07);
}
.ai-btn.secondary:hover { background: rgba(0,0,0,0.03); }

/* Phase banner (between positive & negative) */
.ai-phase {
  text-align: center;
  padding: 28px 16px;
  animation: ai-fadeUp 0.4s ease;
}
.ai-phase-icon {
  font-size: 2.6rem;
  margin-bottom: 12px;
}
.ai-phase h2 {
  font-size: 1.35rem;
  font-weight: 800;
  margin-bottom: 8px;
}
.ai-phase p {
  color: var(--ai-muted);
  font-size: 0.95rem;
  margin-bottom: 20px;
  line-height: 1.45;
}

/* Question */
.ai-qcard {
  width: 100%;
  background: var(--ai-card);
  border-radius: var(--ai-radius);
  padding: 26px 20px;
  box-shadow: var(--ai-shadow);
  text-align: center;
  margin-bottom: 20px;
  border: 1px solid rgba(79, 70, 229, 0.06);
}
.ai-qlabel {
  font-size: 0.72rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--ai-muted);
  margin-bottom: 14px;
}
.ai-sentence {
  font-size: 1.28rem;
  font-weight: 700;
  line-height: 1.55;
  letter-spacing: -0.01em;
  color: var(--ai-text);
}
/* Single clean underline blank — one line only */
.ai-blank {
  display: inline;
  border-bottom: 2.5px solid var(--ai-primary);
  color: transparent;
  padding: 0 18px;
  margin: 0 2px;
  white-space: nowrap;
  vertical-align: baseline;
}
@media (min-width: 768px) {
  .ai-qcard { padding: 32px 28px; }
  .ai-sentence { font-size: 1.5rem; }
  .ai-blank { padding: 0 22px; border-bottom-width: 3px; }
  .ai-chip { min-height: 60px; font-size: 1.2rem; }
  .ai-chips { gap: 12px; }
}

/* Answer chips */
.ai-chips {
  display: grid;
  grid-template-columns: 1fr;
  gap: 10px;
  width: 100%;
  margin-bottom: 14px;
}
@media (min-width: 400px) {
  .ai-chips { grid-template-columns: repeat(3, 1fr); }
  .ai-chips.ai-chips-2 { grid-template-columns: 1fr 1fr; }
}
.ai-chips.ai-chips-2 {
  grid-template-columns: 1fr 1fr;
}
.ai-chip {
  padding: 16px 12px;
  font-size: 1.12rem;
  font-weight: 800;
  border-radius: 14px;
  color: #fff;
  border: none;
  cursor: pointer;
  min-height: 54px;
  font-family: inherit;
  transition: transform 0.12s, opacity 0.15s, filter 0.15s, box-shadow 0.15s;
  letter-spacing: 0.02em;
}
/* Same color for all choices — no color hints */
.ai-chip.neutral,
.ai-chip.am,
.ai-chip.is,
.ai-chip.are,
.ai-chip.amnot,
.ai-chip.isnt,
.ai-chip.arent {
  background: var(--ai-primary);
  box-shadow: 0 4px 12px rgba(79, 70, 229, 0.3);
}
.ai-chip:hover { transform: translateY(-2px); filter: brightness(1.06); }
.ai-chip:active { transform: translateY(1px); }
.ai-chip.correct {
  background: var(--ai-ok) !important;
  box-shadow: 0 4px 12px rgba(22, 163, 74, 0.35) !important;
  outline: 3px solid #fff;
  outline-offset: 2px;
  animation: ai-pop 0.4s ease;
}
.ai-chip.wrong {
  background: var(--ai-bad) !important;
  box-shadow: 0 4px 12px rgba(220, 38, 38, 0.3) !important;
  animation: ai-shake 0.4s ease;
  opacity: 0.9;
}
.ai-chip.dim { opacity: 0.3; pointer-events: none; }

/* Feedback */
.ai-fb {
  width: 100%;
  border-radius: var(--ai-radius);
  padding: 14px 16px;
  text-align: center;
  margin-bottom: 10px;
  animation: ai-fadeUp 0.3s ease;
}
.ai-fb.ok {
  background: #f0fdf4;
  border: 1px solid #bbf7d0;
}
.ai-fb.bad {
  background: #fef2f2;
  border: 1px solid #fecaca;
}
html[data-theme="dark"] .ai-fb.ok { background: #14532d33; border-color: #166534; }
html[data-theme="dark"] .ai-fb.bad { background: #7f1d1d33; border-color: #991b1b; }
.ai-fb-title {
  font-weight: 800;
  font-size: 1.05rem;
  margin-bottom: 4px;
}
.ai-fb.ok .ai-fb-title { color: var(--ai-ok); }
.ai-fb.bad .ai-fb-title { color: var(--ai-bad); }
.ai-fb-sent {
  font-size: 1rem;
  font-weight: 700;
  margin: 5px 0;
}
.ai-fb-exp {
  font-size: 0.85rem;
  color: var(--ai-muted);
  margin-bottom: 6px;
}

/* Animations */
@keyframes ai-pop {
  0% { transform: scale(0.88); }
  50% { transform: scale(1.06); }
  100% { transform: scale(1); }
}
@keyframes ai-shake {
  0%,100% { transform: translateX(0); }
  20% { transform: translateX(-5px); }
  40% { transform: translateX(5px); }
  60% { transform: translateX(-3px); }
  80% { transform: translateX(3px); }
}
@keyframes ai-fadeUp {
  from { opacity: 0; transform: translateY(8px); }
  to { opacity: 1; transform: translateY(0); }
}
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    transition-duration: 0.01ms !important;
  }
}

@media (max-width: 399px) {
  .ai-sentence { font-size: 1.1rem; }
  .ai-chip { font-size: 1.05rem; min-height: 52px; }
  .ai-start h1 { font-size: 1.3rem; }
}

/* ── Correct Sentence options ── */
.cs-prompt {
  text-align: center;
  font-size: 0.95rem;
  font-weight: 600;
  color: var(--ai-muted);
  margin: 0 0 14px;
}
.cs-options {
  display: flex;
  flex-direction: column;
  gap: 12px;
  width: 100%;
  margin-bottom: 14px;
}
.cs-opt {
  display: flex;
  align-items: flex-start;
  gap: 12px;
  width: 100%;
  text-align: left;
  padding: 16px 16px;
  border-radius: 16px;
  border: 2px solid rgba(79, 70, 229, 0.12);
  background: var(--ai-card);
  color: var(--ai-text);
  cursor: pointer;
  font-family: inherit;
  font-size: 1.05rem;
  font-weight: 600;
  line-height: 1.4;
  box-shadow: var(--ai-shadow);
  transition: transform 0.12s, border-color 0.15s, background 0.15s;
  min-height: 64px;
}
.cs-opt:hover {
  transform: translateY(-2px);
  border-color: rgba(79, 70, 229, 0.35);
}
.cs-opt:active { transform: translateY(1px); }
.cs-letter {
  flex-shrink: 0;
  width: 32px;
  height: 32px;
  border-radius: 10px;
  background: rgba(79, 70, 229, 0.12);
  color: var(--ai-primary);
  font-weight: 800;
  font-size: 0.9rem;
  display: grid;
  place-items: center;
}
.cs-text { flex: 1; padding-top: 4px; }
.cs-opt.correct {
  border-color: var(--ai-ok);
  background: #f0fdf4;
  animation: ai-pop 0.4s ease;
}
.cs-opt.correct .cs-letter {
  background: var(--ai-ok);
  color: #fff;
}
.cs-opt.wrong {
  border-color: var(--ai-bad);
  background: #fef2f2;
  animation: ai-shake 0.4s ease;
}
.cs-opt.wrong .cs-letter {
  background: var(--ai-bad);
  color: #fff;
}
.cs-opt.dim {
  opacity: 0.4;
  pointer-events: none;
}
html[data-theme="dark"] .cs-opt.correct { background: #14532d33; }
html[data-theme="dark"] .cs-opt.wrong { background: #7f1d1d33; }
@media (min-width: 768px) {
  .cs-opt { font-size: 1.12rem; padding: 18px 20px; min-height: 72px; }
  .cs-letter { width: 36px; height: 36px; }
}