/* ══════════════════════════════════════════════════
   Infinity Mode — continuous adaptive flow UI
   ══════════════════════════════════════════════════ */

/* ── Stat Rail ── */
.inf-rail {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 16px;
  padding: 10px 16px;
  margin: 0 0 8px;
  border-radius: var(--r1);
  background: var(--card);
  border: 1px solid var(--bdr);
}

.inf-rail-item {
  display: flex;
  align-items: center;
  gap: 4px;
  font-size: 13px;
  font-weight: 600;
}

.inf-rail-val {
  font-variant-numeric: tabular-nums;
}

/* ── Reason Bar ── */
.inf-reason {
  display: flex;
  align-items: center;
  gap: 4px;
  font-size: 11px;
  color: var(--dim);
  padding: 4px 0 8px;
  text-transform: uppercase;
  letter-spacing: 0.04em;
}

/* ── Card Shell ── */
.inf-card {
  background: var(--card);
  border: 1px solid var(--bdr);
  border-radius: var(--r);
  padding: 20px;
  margin: 0 0 12px;
  animation: inf-card-in var(--anim-base) var(--ease-out);
}

@keyframes inf-card-in {
  from { opacity: 0; transform: translateY(12px); }
  to   { opacity: 1; transform: translateY(0); }
}

/* ── Card Badges ── */
.inf-card-badge {
  display: inline-flex;
  align-items: center;
  gap: 4px;
  font-size: 10px;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  padding: 3px 8px;
  border-radius: var(--r1);
  margin: 0 0 12px;
}

.inf-badge-learn     { background: rgba(var(--acc-rgb, 99,102,241), 0.12); color: var(--acc); }
.inf-badge-check     { background: rgba(var(--cyn-rgb, 6,182,212), 0.12); color: var(--cyn); }
.inf-badge-correct   { background: rgba(var(--grn-rgb, 34,197,94), 0.12); color: var(--grn); }
.inf-badge-wrong     { background: rgba(var(--red-rgb, 239,68,68), 0.12); color: var(--red); }
.inf-badge-reinforce { background: rgba(var(--pur-rgb, 168,85,247), 0.12); color: var(--pur); }
.inf-badge-momentum  { background: rgba(var(--amb-rgb, 245,158,11), 0.12); color: var(--amb); }

/* ── Card Content ── */
.inf-card-title {
  font-size: 16px;
  font-weight: 700;
  margin: 0 0 8px;
  color: var(--wh);
}

.inf-card-body {
  font-size: 14px;
  line-height: 1.6;
  color: var(--tx);
}

.inf-learn-line {
  margin: 4px 0;
}

.inf-card-cat {
  font-size: 11px;
  color: var(--dim);
  margin-top: 12px;
  text-transform: uppercase;
  letter-spacing: 0.04em;
}

/* ── Structured Learn Lines ── */
.inf-learn-concept {
  font-weight: 600;
  color: var(--wh);
}

.inf-learn-detail {
  color: var(--tx);
}

.inf-learn-relevance {
  color: var(--dim);
  font-style: italic;
  font-size: 13px;
}

/* ── Structured Explain Sections ── */
.inf-explain-section {
  margin: 0 0 12px;
}

.inf-explain-section:last-child {
  margin-bottom: 0;
}

.inf-explain-label {
  display: flex;
  align-items: center;
  gap: 4px;
  font-size: 11px;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.04em;
  color: var(--dim);
  margin: 0 0 4px;
}

.inf-explain-text {
  font-size: 14px;
  line-height: 1.6;
  color: var(--tx);
}

.inf-explain-watch {
  padding: 8px 10px;
  border-radius: var(--r1);
  background: rgba(var(--amb-rgb, 245,158,11), 0.06);
  border-left: 3px solid var(--amb);
}

.inf-explain-watch .inf-explain-label {
  color: var(--amb);
}

/* ── Reinforce Interactive Card ── */
.inf-reinforce-prompt {
  font-size: 16px;
  font-weight: 600;
  line-height: 1.5;
  color: var(--wh);
  margin: 0 0 16px;
}

.inf-reinforce-hidden {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 6px;
  padding: 20px;
  border-radius: var(--r1);
  border: 1px dashed var(--bdr);
  color: var(--dim);
  font-size: 13px;
}

.inf-reinforce-reveal {
  padding: 12px;
  border-radius: var(--r1);
  background: rgba(var(--pur-rgb, 168,85,247), 0.06);
  border-left: 3px solid var(--pur);
  animation: inf-card-in var(--anim-base) var(--ease-out);
}

.inf-reinforce-answer {
  font-size: 14px;
  line-height: 1.6;
  color: var(--tx);
  margin: 0 0 6px;
}

.inf-reinforce-takeaway {
  font-size: 12px;
  color: var(--dim);
  font-style: italic;
}

/* ── Reveal Button ── */
.inf-btn-reveal {
  background: var(--pur);
  border-color: var(--pur);
  color: #fff;
  flex: 1;
}

.inf-btn-reveal:hover {
  filter: brightness(1.1);
}

.inf-card-qtext {
  font-size: 14px;
  line-height: 1.6;
  color: var(--tx);
  margin: 0 0 16px;
}

.inf-card-qtext p {
  margin: 0 0 8px;
}

.inf-explain-body {
  white-space: pre-wrap;
}

/* ── Choices ── */
.inf-choices {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.inf-choice {
  display: flex;
  align-items: flex-start;
  gap: 10px;
  padding: 12px 14px;
  border-radius: var(--r1);
  border: 1px solid var(--bdr);
  background: var(--bg);
  text-align: left;
  cursor: pointer;
  transition: all var(--anim-fast) ease;
  font-size: 14px;
  color: var(--tx);
  width: 100%;
}

.inf-choice:active {
  transform: scale(var(--press-scale));
}

.inf-choice:hover:not([disabled]) {
  border-color: var(--acc);
}

.inf-choice[disabled] {
  cursor: default;
  opacity: 0.85;
}

.inf-choice-correct {
  border-color: var(--grn) !important;
  background: rgba(var(--grn-rgb, 34,197,94), 0.08);
}

.inf-choice-wrong {
  border-color: var(--red) !important;
  background: rgba(var(--red-rgb, 239,68,68), 0.08);
}

.inf-choice-letter {
  flex-shrink: 0;
  width: 24px;
  height: 24px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 50%;
  background: var(--card);
  border: 1px solid var(--bdr);
  font-size: 12px;
  font-weight: 700;
  color: var(--dim);
}

.inf-choice-correct .inf-choice-letter {
  background: var(--grn);
  border-color: var(--grn);
  color: #fff;
}

.inf-choice-wrong .inf-choice-letter {
  background: var(--red);
  border-color: var(--red);
  color: #fff;
}

.inf-choice-text {
  flex: 1;
  line-height: 1.5;
}

/* ── Momentum Card ── */
.inf-momentum-stats {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 12px;
  margin: 0 0 16px;
}

.inf-momentum-stat {
  text-align: center;
  padding: 10px 8px;
  border-radius: var(--r1);
  background: var(--bg);
  border: 1px solid var(--bdr);
}

.inf-momentum-val {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 4px;
  font-size: 20px;
  font-weight: 700;
}

.inf-momentum-label {
  font-size: 11px;
  color: var(--dim);
  margin-top: 2px;
  text-transform: uppercase;
  letter-spacing: 0.04em;
}

.inf-momentum-msg {
  font-size: 14px;
  color: var(--tx);
  text-align: center;
  line-height: 1.5;
}

/* ── Controls ── */
.inf-controls {
  display: flex;
  align-items: center;
  gap: 10px;
}

.inf-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 6px;
  padding: 10px 20px;
  border-radius: var(--r1);
  font-size: 14px;
  font-weight: 600;
  cursor: pointer;
  border: 1px solid var(--bdr);
  background: var(--card);
  color: var(--tx);
  transition: all var(--anim-fast) var(--ease-out);
}

.inf-btn:active {
  transform: scale(var(--press-scale));
}

.inf-btn-next,
.inf-btn-start,
.inf-btn-resume {
  background: var(--acc);
  border-color: var(--acc);
  color: #fff;
  flex: 1;
}

.inf-btn-next:hover,
.inf-btn-start:hover,
.inf-btn-resume:hover {
  filter: brightness(1.1);
}

.inf-btn-end {
  background: transparent;
  border-color: var(--bdr);
  color: var(--dim);
}

.inf-btn-end:hover {
  border-color: var(--red);
  color: var(--red);
}

.inf-btn-fresh {
  background: transparent;
  border-color: var(--bdr);
  color: var(--dim);
  font-size: 13px;
  padding: 8px 16px;
}

/* ── Start Screen ── */
.inf-start {
  display: flex;
  flex-direction: column;
  align-items: center;
  text-align: center;
  padding: 40px 20px;
  gap: 8px;
}

.inf-start-icon {
  color: var(--acc);
  margin-bottom: 4px;
}

.inf-start-title {
  font-size: 22px;
  font-weight: 700;
  color: var(--wh);
  margin: 0;
}

.inf-start-sub {
  font-size: 14px;
  line-height: 1.5;
  color: var(--dim);
  margin: 0 0 12px;
}

.inf-start-focus {
  display: inline-flex;
  align-items: center;
  gap: 4px;
  font-size: 12px;
  font-weight: 600;
  color: var(--acc);
  padding: 4px 10px;
  border-radius: var(--r1);
  background: rgba(var(--acc-rgb, 99,102,241), 0.08);
  margin-bottom: 16px;
}

.inf-start-resume-info {
  font-size: 12px;
  color: var(--dim);
  margin: 4px 0 8px;
}

/* ── Summary Screen ── */
.inf-summary {
  display: flex;
  flex-direction: column;
  align-items: center;
  text-align: center;
  padding: 40px 20px;
  gap: 8px;
}

.inf-summary-icon {
  color: var(--grn);
  margin-bottom: 4px;
}

.inf-summary-title {
  font-size: 22px;
  font-weight: 700;
  color: var(--wh);
  margin: 0;
}

.inf-summary-time {
  font-size: 13px;
  color: var(--dim);
}

.inf-summary-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 10px;
  width: 100%;
  max-width: 300px;
  margin: 16px 0;
}

.inf-summary-stat {
  padding: 12px 8px;
  border-radius: var(--r1);
  background: var(--card);
  border: 1px solid var(--bdr);
}

.inf-summary-val {
  font-size: 22px;
  font-weight: 700;
}

.inf-summary-label {
  font-size: 11px;
  color: var(--dim);
  margin-top: 2px;
  text-transform: uppercase;
  letter-spacing: 0.04em;
}

.inf-summary-recovery {
  display: inline-flex;
  align-items: center;
  gap: 4px;
  font-size: 13px;
  color: var(--grn);
  padding: 6px 12px;
  border-radius: var(--r1);
  background: rgba(var(--grn-rgb, 34,197,94), 0.08);
  margin: 4px 0 12px;
}

.inf-summary-actions {
  display: flex;
  gap: 10px;
  width: 100%;
  max-width: 320px;
  margin-top: 8px;
}

.inf-summary-actions .inf-btn {
  flex: 1;
}