/* === Game play page === */

.game-page {
  max-width: 800px;
  margin: 0 auto;
  padding: var(--space-3);
}

.game-header-bar {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin: var(--space-3) 0;
  gap: var(--space-2);
  flex-wrap: wrap;
}
.game-header-bar h1 {
  font-size: 1.6rem;
  margin: 0;
}
.game-header-bar .meta {
  color: var(--c-text-soft);
  font-size: 0.9rem;
  margin-top: 4px;
}

.game-shell {
  background: var(--c-surface);
  border: 1px solid var(--c-border);
  border-radius: var(--radius-lg);
  padding: var(--space-3) var(--space-3) var(--space-4);
  box-shadow: var(--shadow);
}

/* === Toolbar === */
.game-toolbar {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: var(--space-2);
  flex-wrap: wrap;
  gap: 8px;
}
.game-q-num {
  font-weight: 700;
  color: var(--c-primary);
  font-size: 0.98rem;
}
.game-running-score {
  background: var(--c-bg);
  padding: 6px 12px;
  border-radius: 999px;
  font-size: 0.88rem;
  color: var(--c-text-soft);
  display: inline-flex;
  align-items: center;
  gap: 4px;
}
.game-running-score strong {
  color: var(--c-accent);
  font-family: var(--font-en);
}

.game-progress-line {
  height: 6px;
  background: var(--c-bg);
  border-radius: 999px;
  margin-bottom: var(--space-3);
  overflow: hidden;
}
.game-progress-fill {
  height: 100%;
  background: linear-gradient(90deg, var(--c-accent), var(--c-primary));
  transition: width 0.4s;
  border-radius: 999px;
}

/* === Scenario card === */
.scenario-card {
  background: linear-gradient(135deg, rgba(212,160,23,0.04), rgba(26,58,92,0.04));
  border: 1px solid var(--c-border);
  border-left: 5px solid var(--c-accent);
  border-radius: var(--radius);
  padding: var(--space-3);
  margin-bottom: var(--space-3);
}
.scenario-label {
  font-size: 0.78rem;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--c-text-soft);
  font-weight: 700;
  margin-bottom: 8px;
  display: flex;
  align-items: center;
  gap: 6px;
}
.scenario-text {
  font-size: 1.08rem;
  line-height: 1.75;
  color: var(--c-text);
}

/* === Step === */
.step {
  margin-bottom: var(--space-3);
  animation: stepFadeIn 0.35s ease-out;
}
@keyframes stepFadeIn {
  from { opacity: 0; transform: translateY(8px); }
  to   { opacity: 1; transform: translateY(0); }
}
.step-label {
  display: flex;
  align-items: center;
  gap: 10px;
  margin-bottom: var(--space-2);
  font-weight: 700;
  color: var(--c-primary);
  font-size: 1rem;
}
.step-num {
  background: var(--c-primary);
  color: white;
  font-size: 0.75rem;
  padding: 3px 10px;
  border-radius: 999px;
  font-weight: 700;
  letter-spacing: 0.05em;
}

/* === Light buttons === */
.light-buttons {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--space-2);
}
.light-btn {
  background: var(--c-surface);
  border: 2px solid var(--c-border);
  padding: var(--space-3) var(--space-2);
  border-radius: var(--radius);
  cursor: pointer;
  font-family: inherit;
  font-size: 1.05rem;
  font-weight: 700;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 6px;
  color: var(--c-text-soft);
  transition: all 0.18s;
}
.light-btn:hover:not(:disabled) {
  transform: translateY(-2px);
  box-shadow: var(--shadow);
}
.light-btn.red:hover:not(:disabled)    { border-color: var(--c-red);    color: var(--c-red);    background: var(--c-red-bg); }
.light-btn.yellow:hover:not(:disabled) { border-color: var(--c-yellow); color: var(--c-yellow); background: var(--c-yellow-bg); }
.light-btn.green:hover:not(:disabled)  { border-color: var(--c-green);  color: var(--c-green);  background: var(--c-green-bg); }
.light-btn:disabled { cursor: default; }
.light-btn.correct {
  border-color: var(--c-green);
  background: var(--c-green-bg);
  color: var(--c-green);
}
.light-btn.wrong {
  border-color: var(--c-red);
  background: var(--c-red-bg);
  color: var(--c-red);
}
.light-emoji {
  font-size: 1.8rem;
  line-height: 1;
}

/* === Explain options === */
.explain-options {
  display: flex;
  flex-direction: column;
  gap: 10px;
}
.explain-btn {
  background: var(--c-surface);
  border: 2px solid var(--c-border);
  padding: 14px 18px;
  border-radius: var(--radius-sm);
  cursor: pointer;
  font-family: inherit;
  font-size: 0.98rem;
  line-height: 1.65;
  color: var(--c-text);
  text-align: left;
  transition: all 0.15s;
}
.explain-btn:hover:not(:disabled) {
  border-color: var(--c-primary);
  background: var(--c-bg);
  transform: translateY(-1px);
}
.explain-btn:disabled { cursor: default; }
.explain-btn.correct {
  border-color: var(--c-green);
  background: var(--c-green-bg);
  color: var(--c-green);
  font-weight: 600;
}
.explain-btn.wrong {
  border-color: var(--c-red);
  background: var(--c-red-bg);
  color: var(--c-red);
  font-weight: 600;
}

/* === Feedback === */
.game-feedback {
  margin: var(--space-3) 0;
  padding: var(--space-3);
  border-radius: var(--radius);
  border-left: 5px solid var(--c-text-soft);
  background: var(--c-bg);
  animation: fadeIn 0.3s ease-out;
}
.game-feedback.great { border-left-color: var(--c-green); background: var(--c-green-bg); }
.game-feedback.half  { border-left-color: var(--c-yellow); background: var(--c-yellow-bg); }
.game-feedback.wrong { border-left-color: var(--c-red); background: var(--c-red-bg); }
.fb-header {
  font-weight: 700;
  font-size: 1.05rem;
  margin-bottom: var(--space-2);
}
.game-feedback.great .fb-header { color: var(--c-green); }
.game-feedback.half .fb-header  { color: var(--c-yellow); }
.game-feedback.wrong .fb-header { color: var(--c-red); }
.fb-detail { font-size: 0.92rem; }
.fb-row {
  display: flex;
  gap: 8px;
  padding: 3px 0;
}
.fb-key { font-weight: 700; min-width: 60px; color: var(--c-text-soft); }
.fb-val.ok  { color: var(--c-green); }
.fb-val.bad { color: var(--c-red); }

/* === Next button === */
.game-actions {
  display: flex;
  justify-content: flex-end;
  margin-top: var(--space-2);
}
.game-next-btn {
  background: var(--c-primary);
  color: white;
  border: 0;
  padding: 14px 26px;
  border-radius: 10px;
  font-family: inherit;
  font-weight: 700;
  font-size: 1.02rem;
  cursor: pointer;
  display: inline-flex;
  align-items: center;
  gap: 8px;
  transition: background 0.15s;
}
.game-next-btn:hover { background: var(--c-primary-light); }

/* === End screen === */
.game-end {
  text-align: center;
  padding: var(--space-5) var(--space-3);
  background: var(--c-surface);
  border-radius: var(--radius-lg);
  border: 1px solid var(--c-border);
  box-shadow: var(--shadow);
  animation: bounceIn 0.6s ease-out;
}
.game-end.gold   { border-top: 6px solid var(--c-accent); }
.game-end.silver { border-top: 6px solid #95a3b3; }
.game-end.bronze { border-top: 6px solid #c69870; }
.game-end.try-again { border-top: 6px solid var(--c-text-soft); }
.end-emoji {
  font-size: 4rem;
  line-height: 1;
  margin-bottom: var(--space-2);
}
.end-title {
  font-size: 1.4rem;
  font-weight: 700;
  color: var(--c-primary);
  margin-bottom: var(--space-2);
}
.end-score {
  display: flex;
  align-items: baseline;
  justify-content: center;
  gap: 6px;
  margin: var(--space-2) 0;
}
.big-num {
  font-size: 4.5rem;
  font-family: var(--font-en);
  font-weight: 800;
  color: var(--c-accent);
  line-height: 1;
}
.end-divider {
  font-size: 2rem;
  color: var(--c-text-soft);
  margin: 0 4px;
}
.end-total {
  font-size: 2rem;
  font-family: var(--font-en);
  font-weight: 600;
  color: var(--c-text-soft);
}
.end-pct {
  font-family: var(--font-en);
  color: var(--c-text-soft);
  font-weight: 600;
  margin-bottom: var(--space-2);
}
.end-msg {
  color: var(--c-text);
  font-size: 1rem;
  max-width: 500px;
  margin: var(--space-2) auto var(--space-3);
}
.end-cert {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  background: var(--c-green-bg);
  color: var(--c-green);
  font-weight: 700;
  padding: 8px 18px;
  border-radius: 999px;
  margin-bottom: var(--space-3);
}
.end-actions {
  display: flex;
  justify-content: center;
  gap: 10px;
  flex-wrap: wrap;
  margin-top: var(--space-3);
}
.game-end-btn {
  background: var(--c-primary);
  color: white;
  border: 0;
  padding: 12px 24px;
  border-radius: 10px;
  font-family: inherit;
  font-weight: 700;
  font-size: 0.98rem;
  cursor: pointer;
  text-decoration: none;
  display: inline-flex;
  align-items: center;
  gap: 6px;
  transition: all 0.15s;
}
.game-end-btn.primary:hover { background: var(--c-primary-light); }
.game-end-btn.ghost {
  background: transparent;
  color: var(--c-primary);
  border: 1px solid var(--c-border);
}
.game-end-btn.ghost:hover { border-color: var(--c-primary); }

/* ============================================================ */
/* === Classify game (用途分類) === */
/* ============================================================ */
.classify-shell {
  background: var(--c-surface);
  border: 1px solid var(--c-border);
  border-radius: var(--radius-lg);
  padding: var(--space-3) var(--space-3) var(--space-4);
  box-shadow: var(--shadow);
}
.classify-card-area {
  display: flex;
  justify-content: center;
  margin: var(--space-3) 0 var(--space-4);
}
.classify-card {
  background: linear-gradient(135deg, #ffffff, #f8f9fa);
  border: 2px solid var(--c-border);
  border-radius: var(--radius-lg);
  padding: var(--space-4) var(--space-3);
  min-height: 140px;
  width: 100%;
  max-width: 540px;
  display: flex;
  flex-direction: column;
  justify-content: center;
  position: relative;
  box-shadow: var(--shadow);
  transition: all 0.3s;
  animation: cardPop 0.35s ease-out;
}
@keyframes cardPop {
  from { opacity: 0; transform: scale(0.95); }
  to   { opacity: 1; transform: scale(1); }
}
.classify-card.card-correct {
  border-color: var(--c-green);
  background: linear-gradient(135deg, #ffffff, var(--c-green-bg));
}
.classify-card.card-wrong {
  border-color: var(--c-red);
  background: linear-gradient(135deg, #ffffff, var(--c-red-bg));
  animation: cardShake 0.4s ease-out;
}
@keyframes cardShake {
  0%, 100% { transform: translateX(0); }
  20% { transform: translateX(-6px); }
  40% { transform: translateX(6px); }
  60% { transform: translateX(-4px); }
  80% { transform: translateX(4px); }
}
.card-label {
  display: flex;
  align-items: center;
  gap: 6px;
  font-size: 0.75rem;
  font-weight: 700;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--c-text-soft);
  margin-bottom: var(--space-2);
}
.card-text {
  font-size: 1.15rem;
  line-height: 1.7;
  color: var(--c-text);
  font-weight: 500;
}
.card-feedback {
  margin-top: var(--space-3);
  padding: var(--space-2);
  border-radius: var(--radius-sm);
  display: flex;
  gap: 12px;
  align-items: flex-start;
  animation: fadeIn 0.3s;
}
.card-feedback.great { background: var(--c-green-bg); color: var(--c-green); }
.card-feedback.wrong { background: var(--c-red-bg); color: var(--c-red); }
.fb-mark {
  font-size: 1.6rem;
  font-weight: 800;
  line-height: 1;
  flex-shrink: 0;
}
.fb-text {
  font-size: 0.95rem;
  line-height: 1.65;
  color: var(--c-text);
}
.fb-text strong {
  display: block;
  margin-bottom: 2px;
}
.card-feedback.great .fb-text strong { color: var(--c-green); }
.card-feedback.wrong .fb-text strong { color: var(--c-red); }

.classify-prompt {
  text-align: center;
  font-weight: 600;
  color: var(--c-text-soft);
  margin-bottom: var(--space-2);
  font-size: 0.95rem;
}
.bucket-row {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--space-2);
}
.bucket-btn {
  position: relative;
  background: var(--c-surface);
  border: 3px solid var(--c-border);
  padding: var(--space-3) var(--space-2);
  border-radius: var(--radius);
  cursor: pointer;
  font-family: inherit;
  font-size: 1.05rem;
  font-weight: 700;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 6px;
  color: var(--c-text);
  transition: all 0.18s;
}
.bucket-btn:hover:not(:disabled) {
  transform: translateY(-3px);
  box-shadow: var(--shadow-lg);
}
.bucket-btn.bucket-green:hover:not(:disabled)  { border-color: var(--c-green);  background: var(--c-green-bg); }
.bucket-btn.bucket-yellow:hover:not(:disabled) { border-color: var(--c-yellow); background: var(--c-yellow-bg); }
.bucket-btn.bucket-red:hover:not(:disabled)    { border-color: var(--c-red);    background: var(--c-red-bg); }
.bucket-btn:disabled { cursor: default; transform: none; }
.bucket-btn.correct {
  border-color: var(--c-green);
  background: var(--c-green-bg);
  animation: bucketBounce 0.4s ease-out;
}
.bucket-btn.wrong {
  border-color: var(--c-red);
  background: var(--c-red-bg);
}
.bucket-btn.correct-indicator {
  border-color: var(--c-green);
  background: var(--c-green-bg);
  opacity: 0.7;
  animation: bucketPulse 1s infinite;
}
@keyframes bucketBounce {
  0%, 100% { transform: scale(1); }
  50% { transform: scale(1.06); }
}
@keyframes bucketPulse {
  0%, 100% { box-shadow: 0 0 0 0 rgba(45, 138, 62, 0.4); }
  50% { box-shadow: 0 0 0 8px rgba(45, 138, 62, 0); }
}
.bucket-emoji {
  font-size: 2rem;
  line-height: 1;
}
.bucket-label {
  font-size: 1rem;
}
.bucket-count {
  background: var(--c-bg);
  color: var(--c-text-soft);
  font-size: 0.78rem;
  padding: 2px 10px;
  border-radius: 999px;
  font-weight: 600;
  font-family: var(--font-en);
}

.classify-next-btn {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  background: var(--c-primary);
  color: white;
  border: 0;
  padding: 14px 28px;
  border-radius: 10px;
  font-family: inherit;
  font-weight: 700;
  font-size: 1.02rem;
  cursor: pointer;
  margin: 0 auto var(--space-2);
  transition: background 0.15s;
}
.classify-next-btn:hover { background: var(--c-primary-light); }

/* === Classify review (end screen) === */
.classify-review {
  margin: var(--space-4) 0 var(--space-3);
  text-align: left;
}
.review-title {
  text-align: center;
  font-weight: 700;
  color: var(--c-primary);
  font-size: 1.15rem;
  margin-bottom: var(--space-2);
}
.review-columns {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--space-2);
}
.review-col {
  background: var(--c-surface);
  border: 1px solid var(--c-border);
  border-radius: var(--radius);
  padding: var(--space-2);
}
.review-col.col-green  { border-top: 4px solid var(--c-green); }
.review-col.col-yellow { border-top: 4px solid var(--c-yellow); }
.review-col.col-red    { border-top: 4px solid var(--c-red); }
.review-col-head {
  display: flex;
  align-items: center;
  gap: 6px;
  font-weight: 700;
  color: var(--c-text);
  padding-bottom: 6px;
  border-bottom: 1px solid var(--c-border);
  margin-bottom: 8px;
  font-size: 0.92rem;
}
.review-col-head .bucket-emoji { font-size: 1.2rem; }
.review-count {
  margin-left: auto;
  background: var(--c-bg);
  color: var(--c-text-soft);
  font-size: 0.78rem;
  padding: 2px 10px;
  border-radius: 999px;
  font-family: var(--font-en);
}
.review-list {
  list-style: none;
  padding: 0;
  margin: 0;
}
.review-item {
  display: flex;
  gap: 8px;
  padding: 6px 0;
  font-size: 0.85rem;
  line-height: 1.5;
  border-bottom: 1px dashed var(--c-border);
}
.review-item:last-child { border-bottom: 0; }
.review-mark {
  font-weight: 800;
  flex-shrink: 0;
}
.review-item.ok .review-mark { color: var(--c-green); }
.review-item.bad .review-mark { color: var(--c-red); }
.review-item.bad .review-text { color: var(--c-text-soft); }
.review-correct-hint {
  display: block;
  font-size: 0.78rem;
  color: var(--c-primary-light);
  margin-top: 3px;
  font-weight: 600;
}
.review-empty {
  color: var(--c-text-soft);
  font-style: italic;
  font-size: 0.85rem;
  padding: 6px 0;
}

/* ============================================================ */
/* === Concept Card game (概念卡學習) === */
/* ============================================================ */
.cc-shell {
  background: var(--c-surface);
  border: 1px solid var(--c-border);
  border-radius: var(--radius-lg);
  padding: var(--space-3) var(--space-3) var(--space-4);
  box-shadow: var(--shadow);
}

.cc-hint {
  font-size: 0.85rem;
  color: var(--c-text-soft);
  display: inline-flex;
  align-items: center;
  gap: 4px;
  background: var(--c-bg);
  padding: 4px 12px;
  border-radius: 999px;
}

/* === Flashcard (flip animation) === */
.flashcard-wrap {
  perspective: 1500px;
  margin: var(--space-3) 0 var(--space-4);
  display: flex;
  justify-content: center;
}
.flashcard {
  width: 100%;
  max-width: 540px;
  min-height: 360px;
  position: relative;
  transition: transform 0.7s cubic-bezier(0.4, 0.0, 0.2, 1);
  transform-style: preserve-3d;
  cursor: pointer;
  user-select: none;
}
.flashcard.flipped {
  transform: rotateY(180deg);
}
.flashcard-face {
  position: absolute;
  inset: 0;
  -webkit-backface-visibility: hidden;
  backface-visibility: hidden;
  border-radius: var(--radius-lg);
  padding: var(--space-4) var(--space-3);
  display: flex;
  flex-direction: column;
  box-shadow: var(--shadow);
  border: 2px solid var(--c-border);
  overflow-y: auto;
}
.flashcard-front {
  background: linear-gradient(135deg, var(--c-primary) 0%, var(--c-primary-light) 100%);
  color: white;
  align-items: center;
  justify-content: center;
  text-align: center;
  border: 0;
}
.flashcard-back {
  background: linear-gradient(135deg, #ffffff, var(--c-accent-soft));
  color: var(--c-text);
  transform: rotateY(180deg);
}
.cc-emoji {
  font-size: 5rem;
  line-height: 1;
  margin-bottom: var(--space-2);
}
.cc-term {
  font-size: 2rem;
  font-weight: 800;
  letter-spacing: -0.01em;
  margin-bottom: var(--space-3);
}
.cc-flip-hint {
  font-size: 0.9rem;
  opacity: 0.85;
  font-weight: 500;
  padding: 8px 18px;
  border: 1px solid rgba(255,255,255,0.3);
  border-radius: 999px;
}

.cc-back-header {
  display: flex;
  align-items: center;
  gap: 10px;
  padding-bottom: var(--space-2);
  margin-bottom: var(--space-2);
  border-bottom: 2px solid var(--c-accent);
}
.cc-back-emoji {
  font-size: 2rem;
  line-height: 1;
}
.cc-back-term {
  font-size: 1.4rem;
  font-weight: 800;
  color: var(--c-primary);
}
.cc-section {
  margin-bottom: var(--space-3);
}
.cc-section:last-child { margin-bottom: 0; }
.cc-section-label {
  font-size: 0.72rem;
  font-weight: 700;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--c-text-soft);
  margin-bottom: 6px;
}
.cc-section-text {
  font-size: 1rem;
  line-height: 1.7;
  color: var(--c-text);
}

/* === Browse nav === */
.cc-nav {
  display: flex;
  justify-content: space-between;
  gap: var(--space-2);
  margin-top: var(--space-3);
  flex-wrap: wrap;
}
.cc-nav-btn {
  background: var(--c-primary);
  color: white;
  border: 0;
  padding: 12px 22px;
  border-radius: 10px;
  font-family: inherit;
  font-weight: 700;
  font-size: 0.98rem;
  cursor: pointer;
  display: inline-flex;
  align-items: center;
  gap: 8px;
  text-decoration: none;
  transition: all 0.15s;
}
.cc-nav-btn.primary:hover:not(:disabled) { background: var(--c-primary-light); }
.cc-nav-btn.ghost {
  background: transparent;
  color: var(--c-primary);
  border: 1px solid var(--c-border);
}
.cc-nav-btn.ghost:hover:not(:disabled) { border-color: var(--c-primary); }
.cc-nav-btn:disabled { opacity: 0.4; cursor: not-allowed; }
.cc-nav-btn.big { font-size: 1.05rem; padding: 14px 28px; }

/* === Quiz intro === */
.cc-intro {
  text-align: center;
  padding: var(--space-5) var(--space-3);
}
.cc-intro-emoji {
  font-size: 5rem;
  line-height: 1;
  margin-bottom: var(--space-2);
}
.cc-intro-title {
  color: var(--c-primary);
  font-size: 1.8rem;
  margin-bottom: var(--space-2);
}
.cc-intro-desc {
  color: var(--c-text-soft);
  font-size: 1.05rem;
  margin-bottom: var(--space-4);
}
.cc-intro-actions {
  display: flex;
  justify-content: center;
  gap: var(--space-2);
  flex-wrap: wrap;
}

/* === Quiz === */
.cc-quiz-question {
  font-size: 1.15rem;
  line-height: 1.7;
  padding: var(--space-3);
  background: var(--c-bg);
  border-radius: var(--radius);
  border-left: 5px solid var(--c-primary);
  margin-bottom: var(--space-3);
  font-weight: 500;
}
.cc-quiz-options {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 12px;
}
.cc-quiz-opt {
  background: var(--c-surface);
  border: 2px solid var(--c-border);
  padding: var(--space-3);
  border-radius: var(--radius);
  cursor: pointer;
  font-family: inherit;
  display: flex;
  align-items: center;
  gap: 12px;
  text-align: left;
  transition: all 0.15s;
  color: var(--c-text);
}
.cc-quiz-opt:hover:not(:disabled) {
  border-color: var(--c-primary);
  background: var(--c-bg);
  transform: translateY(-2px);
}
.cc-quiz-opt:disabled { cursor: default; transform: none; }
.cc-quiz-opt.correct {
  border-color: var(--c-green);
  background: var(--c-green-bg);
  color: var(--c-green);
  font-weight: 600;
}
.cc-quiz-opt.wrong {
  border-color: var(--c-red);
  background: var(--c-red-bg);
  color: var(--c-red);
  font-weight: 600;
}
.cc-quiz-opt-emoji {
  font-size: 1.8rem;
  line-height: 1;
  flex-shrink: 0;
}
.cc-quiz-opt-label {
  font-size: 1rem;
  font-weight: 600;
  line-height: 1.4;
}

/* ============================================================ */
/* === Principle Duel game (原則對決) === */
/* ============================================================ */
.pd-shell {
  background: var(--c-surface);
  border: 1px solid var(--c-border);
  border-radius: var(--radius-lg);
  padding: var(--space-3) var(--space-3) var(--space-4);
  box-shadow: var(--shadow);
}
.pd-scenario {
  background: linear-gradient(135deg, rgba(212,160,23,0.06), rgba(26,58,92,0.04));
  border: 1px solid var(--c-border);
  border-left: 5px solid var(--c-accent);
  border-radius: var(--radius);
  padding: var(--space-3);
  margin: var(--space-2) 0 var(--space-3);
}
.pd-prompt {
  text-align: center;
  font-weight: 700;
  color: var(--c-primary);
  font-size: 1.1rem;
  margin: var(--space-3) 0;
}

/* === Arena (two cards + VS) === */
.pd-arena {
  display: grid;
  grid-template-columns: 1fr auto 1fr;
  gap: var(--space-2);
  align-items: stretch;
  margin-bottom: var(--space-3);
}
.pd-principle {
  background: var(--c-surface);
  border: 3px solid var(--c-border);
  border-radius: var(--radius-lg);
  padding: var(--space-3);
  cursor: pointer;
  font-family: inherit;
  display: flex;
  flex-direction: column;
  align-items: center;
  text-align: center;
  gap: 10px;
  transition: all 0.2s;
  color: var(--c-text);
  position: relative;
  overflow: hidden;
}
.pd-principle::before {
  content: "";
  position: absolute;
  inset: 0;
  background: radial-gradient(ellipse at top, rgba(26,58,92,0.04), transparent 60%);
  pointer-events: none;
}
.pd-principle:hover:not(:disabled) {
  transform: translateY(-3px) scale(1.02);
  box-shadow: var(--shadow-lg);
  border-color: var(--c-accent);
}
.pd-principle:disabled { cursor: default; }
.pd-principle.winner {
  border-color: var(--c-green);
  background: var(--c-green-bg);
  transform: scale(1.04);
  box-shadow: 0 0 0 4px rgba(45,138,62,0.15);
  animation: winnerGlow 1.5s ease-out;
}
@keyframes winnerGlow {
  0% { box-shadow: 0 0 0 0 rgba(45,138,62,0.4); }
  100% { box-shadow: 0 0 0 4px rgba(45,138,62,0.15); }
}
.pd-principle.loser {
  opacity: 0.45;
  filter: grayscale(0.4);
  transform: scale(0.97);
}
.pd-principle.wrong-pick {
  border-color: var(--c-red);
  background: var(--c-red-bg);
  opacity: 0.7;
  filter: none;
}
.pd-principle-emoji {
  font-size: 3rem;
  line-height: 1;
}
.pd-principle-name {
  font-size: 1.2rem;
  font-weight: 800;
  color: var(--c-primary);
}
.pd-principle.winner .pd-principle-name { color: var(--c-green); }
.pd-principle.wrong-pick .pd-principle-name { color: var(--c-red); }
.pd-principle-arg {
  font-size: 0.88rem;
  color: var(--c-text-soft);
  line-height: 1.55;
  font-style: italic;
}

.pd-vs {
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 0 6px;
}
.pd-vs-text {
  font-family: var(--font-en);
  font-size: 1.6rem;
  font-weight: 900;
  color: var(--c-accent);
  background: var(--c-bg);
  width: 56px;
  height: 56px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  border: 3px solid var(--c-accent);
  box-shadow: var(--shadow);
  letter-spacing: -0.05em;
}

/* === Feedback === */
.pd-feedback {
  margin-top: var(--space-3);
  padding: var(--space-3);
  border-radius: var(--radius);
  border-left: 5px solid var(--c-text-soft);
  background: var(--c-bg);
  animation: fadeIn 0.3s;
}
.pd-feedback.great { border-left-color: var(--c-green); background: var(--c-green-bg); }
.pd-feedback.wrong { border-left-color: var(--c-red); background: var(--c-red-bg); }
.pd-fb-header {
  font-weight: 700;
  font-size: 1.02rem;
  margin-bottom: 8px;
}
.pd-feedback.great .pd-fb-header { color: var(--c-green); }
.pd-feedback.wrong .pd-fb-header { color: var(--c-red); }
.pd-fb-explain {
  font-size: 0.95rem;
  line-height: 1.7;
  color: var(--c-text);
}

/* === End-screen recap === */
.pd-review {
  margin: var(--space-4) 0 var(--space-3);
  text-align: left;
}
.pd-review-list {
  list-style: none;
  padding: 0;
  margin: 0;
  background: var(--c-surface);
  border: 1px solid var(--c-border);
  border-radius: var(--radius);
  overflow: hidden;
}
.pd-review-item {
  display: grid;
  grid-template-columns: auto auto 1fr;
  gap: 12px;
  padding: var(--space-2) var(--space-3);
  font-size: 0.92rem;
  line-height: 1.55;
  border-bottom: 1px solid var(--c-border);
  align-items: start;
}
.pd-review-item:last-child { border-bottom: 0; }
.pd-review-num {
  font-family: var(--font-en);
  font-weight: 700;
  color: var(--c-text-soft);
  min-width: 22px;
}
.pd-review-mark {
  font-weight: 800;
  font-size: 1rem;
}
.pd-review-item.ok .pd-review-mark { color: var(--c-green); }
.pd-review-item.bad .pd-review-mark { color: var(--c-red); }
.pd-review-text {
  display: flex;
  flex-direction: column;
  gap: 3px;
}
.pd-review-scen {
  color: var(--c-text);
  font-size: 0.88rem;
}
.pd-review-winner {
  font-size: 0.82rem;
  color: var(--c-primary-light);
  font-weight: 600;
}

/* === Responsive === */
@media (max-width: 600px) {
  .light-buttons {
    grid-template-columns: 1fr;
  }
  .light-btn {
    flex-direction: row;
    justify-content: center;
    padding: var(--space-2);
  }
  .light-emoji { font-size: 1.4rem; }
  .scenario-text { font-size: 1rem; }
  .big-num { font-size: 3.5rem; }

  /* classify responsive */
  .bucket-row { grid-template-columns: 1fr; }
  .bucket-btn {
    flex-direction: row;
    justify-content: flex-start;
    padding: var(--space-2);
    gap: 12px;
  }
  .bucket-emoji { font-size: 1.5rem; }
  .bucket-count { margin-left: auto; }
  .review-columns { grid-template-columns: 1fr; }
  .card-text { font-size: 1rem; }

  /* concept card responsive */
  .flashcard { min-height: 420px; }
  .cc-emoji { font-size: 4rem; }
  .cc-term { font-size: 1.6rem; }
  .cc-quiz-options { grid-template-columns: 1fr; }
  .cc-quiz-opt { padding: var(--space-2); }
  .cc-intro-title { font-size: 1.4rem; }
  .cc-intro-emoji { font-size: 4rem; }

  /* principle duel responsive */
  .pd-arena {
    grid-template-columns: 1fr;
    gap: var(--space-2);
  }
  .pd-vs {
    padding: var(--space-1) 0;
    transform: rotate(0);
  }
  .pd-vs-text { width: 44px; height: 44px; font-size: 1.3rem; }
  .pd-principle { padding: var(--space-2); }
  .pd-principle-emoji { font-size: 2.4rem; }
  .pd-principle-name { font-size: 1.05rem; }
}