/* ============================================================
   Quiz Pages — Enhanced Design v2
   Design DNA: glassmorphism nav / spring hover / SVG ring /
   stagger entrance / clamp fluid type / --tc per-type color
   ============================================================ */

:root {
  --success-q: #16a34a; --success-bg: #f0fdf4; --success-border: #bbf7d0;
  --error-q: #dc2626;   --error-bg: #fef2f2;   --error-border: #fecaca;
  --warning-q: #f59e0b;  --warning-bg: #fffbeb;
  --diff-1: #52c41a; --diff-2: #73d13d; --diff-3: #faad14; --diff-4: #ff7a45; --diff-5: #f5222d;
  --surface-variant: #f1f5f9;
  --ease-spring: cubic-bezier(0.34, 1.56, 0.64, 1);
  --ease-standard: cubic-bezier(0.2, 0, 0, 1);
  --ease-decelerate: cubic-bezier(0, 0, 0.2, 1);
  --dur-fast: 150ms; --dur-normal: 250ms; --dur-medium: 300ms; --dur-slow: 400ms;
  --shadow-xl: 0px 12px 32px rgba(0,0,0,0.10), 0px 4px 12px rgba(0,0,0,0.05);
}

/* ===== Entrance animations ===== */
@keyframes fadeInUp { from { opacity: 0; transform: translateY(12px); } to { opacity: 1; transform: translateY(0); } }
.fade-in { animation: fadeInUp 400ms var(--ease-decelerate) both; }
.s1 { animation-delay: 0.06s; } .s2 { animation-delay: 0.12s; }
.s3 { animation-delay: 0.18s; } .s4 { animation-delay: 0.24s; }
.s5 { animation-delay: 0.30s; } .s6 { animation-delay: 0.36s; }

/* ===== Focus visible ===== */
:focus-visible { outline: 2px solid var(--primary); outline-offset: 2px; border-radius: 4px; }

/* ===== Stats Panel (quiz/index.html) ===== */
.quiz-stats-card { padding: clamp(16px, 3vw, 24px); }
.quiz-stats { display: grid; grid-template-columns: 1fr 1fr 1fr; gap: 8px; margin-bottom: 14px; }
.quiz-stat { text-align: center; padding: 12px 8px; border-radius: 10px; background: var(--surface-variant); transition: transform var(--dur-fast) var(--ease-standard); }
.quiz-stat:hover { transform: translateY(-2px); }

.quiz-stat-num { font-size: clamp(1.1rem, 2.5vw, 1.4rem); font-weight: 800; line-height: 1.2; }
.quiz-stat-num .sub { font-size: 0.75rem; font-weight: 500; color: var(--text-tertiary); }
.quiz-stat-label { font-size: 0.72rem; color: var(--text-tertiary); margin-top: 2px; }

/* Stats: stat-total / stat-done / stat-correct / stat-wrong / stat-accuracy colors */
.stat-total { color: var(--text); }
.stat-done { color: var(--primary); }
.stat-correct { color: var(--success-q); }
.stat-wrong { color: var(--error-q); }
.stat-accuracy { color: var(--primary); }
.stat-high { color: var(--success-q); }
.stat-mid { color: var(--warning-q); }
.stat-low { color: var(--error-q); }

.quiz-progress-section { border-top: 1px solid var(--border-light); padding-top: 12px; }
.quiz-progress-track { flex: 1; height: 6px; background: var(--border-light); border-radius: 3px; overflow: hidden; }
.quiz-progress-fill { height: 100%; background: linear-gradient(90deg, var(--primary), var(--primary-light)); border-radius: 3px; transition: width 600ms var(--ease-decelerate); }
.quiz-progress-footer { display: flex; align-items: center; gap: 12px; margin-top: 8px; }
.quiz-progress-text { font-size: 0.78rem; color: var(--text-secondary); white-space: nowrap; }

/* ===== Quiz Type Cards (quiz/index.html) ===== */
/* Override .card-grid for quiz type cards */
.quiz-type-grid { display: grid; grid-template-columns: repeat(2, 1fr); gap: 10px; }
@media (max-width: 480px) { .quiz-type-grid { gap: 8px; } }

.qtype-card { position: relative; display: flex; flex-direction: column; gap: 8px; padding: 14px 16px; border: 1px solid var(--border-light); border-radius: 10px; background: var(--surface); box-shadow: var(--shadow-sm); transition: all var(--dur-fast) var(--ease-standard); overflow: hidden; }
.qtype-card::before { content: ''; position: absolute; left: 0; top: 0; bottom: 0; width: 3px; background: var(--tc, var(--primary)); transform: scaleY(0); transform-origin: center; transition: transform var(--dur-normal) var(--ease-spring); }
.qtype-card:hover { box-shadow: var(--shadow-md); border-color: var(--border); transform: translateY(-2px); }
.qtype-card:hover::before { transform: scaleY(1); }
.qtype-card:active { transform: scale(0.97); }

.qtype-head { display: flex; align-items: center; gap: 10px; }
.qtype-ico { width: 36px; height: 36px; border-radius: 10px; display: flex; align-items: center; justify-content: center; font-size: 1.05rem; flex-shrink: 0; }
.qtype-body { flex: 1; min-width: 0; }
.qtype-name { font-size: 0.88rem; font-weight: 600; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
.qtype-count { font-size: 0.72rem; color: var(--text-tertiary); }
.qtype-arrow { color: var(--text-tertiary); font-size: 0.8rem; flex-shrink: 0; }

.qtype-diff-bar { display: flex; gap: 1px; height: 4px; border-radius: 2px; overflow: hidden; }
.qtype-diff-bar span:nth-child(1) { background: var(--diff-1); }
.qtype-diff-bar span:nth-child(2) { background: var(--diff-2); }
.qtype-diff-bar span:nth-child(3) { background: var(--diff-3); }
.qtype-diff-bar span:nth-child(4) { background: var(--diff-4); }
.qtype-diff-bar span:nth-child(5) { background: var(--diff-5); }

.qtype-progress { font-size: 0.68rem; color: var(--text-tertiary); display: flex; justify-content: space-between; }

/* Per-type color theming via data-type */
.qtype-card[data-type="时态语态"] { --tc: #dc2626; } .qtype-card[data-type="时态语态"] .qtype-ico { background: rgba(220,38,38,0.1); color: #dc2626; }
.qtype-card[data-type="非谓语动词"] { --tc: #16a34a; } .qtype-card[data-type="非谓语动词"] .qtype-ico { background: rgba(22,163,74,0.1); color: #16a34a; }
.qtype-card[data-type="虚拟语气"] { --tc: #ca8a04; } .qtype-card[data-type="虚拟语气"] .qtype-ico { background: rgba(202,138,4,0.1); color: #ca8a04; }
.qtype-card[data-type="从句"] { --tc: #2563eb; } .qtype-card[data-type="从句"] .qtype-ico { background: rgba(37,99,235,0.1); color: #2563eb; }
.qtype-card[data-type="倒装强调"] { --tc: #1d4ed8; } .qtype-card[data-type="倒装强调"] .qtype-ico { background: rgba(29,78,216,0.1); color: #1d4ed8; }
.qtype-card[data-type="主谓一致"] { --tc: #ca8a04; } .qtype-card[data-type="主谓一致"] .qtype-ico { background: rgba(202,138,4,0.1); color: #ca8a04; }
.qtype-card[data-type="词法辨析"] { --tc: #db2777; } .qtype-card[data-type="词法辨析"] .qtype-ico { background: rgba(219,39,119,0.1); color: #db2777; }
.qtype-card[data-type="固定句型"] { --tc: #dc2626; } .qtype-card[data-type="固定句型"] .qtype-ico { background: rgba(220,38,38,0.1); color: #dc2626; }
.qtype-card[data-type="综合"] { --tc: #2563eb; } .qtype-card[data-type="综合"] .qtype-ico { background: rgba(37,99,235,0.1); color: #2563eb; }
.qtype-card[data-type="all"] { --tc: var(--primary); } .qtype-card[data-type="all"] .qtype-ico { background: var(--primary-bg); color: var(--primary); }

/* ===== Quick Entry Cards (quiz/index.html) ===== */
.quick-grid { display: grid; grid-template-columns: repeat(2, 1fr); gap: 10px; }
@media (max-width: 480px) { .quick-grid { gap: 8px; } }

.quick-card { position: relative; display: flex; flex-direction: column; gap: 4px; padding: 16px; border: 1px solid var(--border-light); border-radius: 14px; background: var(--surface); box-shadow: var(--shadow-sm); transition: all var(--dur-fast) var(--ease-standard); overflow: hidden; min-height: 88px; }
.quick-card:hover { box-shadow: var(--shadow-md); transform: translateY(-2px); }
.quick-card:active { transform: scale(0.98); }
.quick-card--wrong::before { content: ''; position: absolute; left: 0; top: 0; bottom: 0; width: 4px; background: var(--error-q); }
.quick-card--random { background: linear-gradient(135deg, var(--primary-bg), #dbeafe); border-color: var(--primary-border); }
.quick-badge { position: absolute; top: 8px; right: 8px; background: var(--error-q); color: #fff; font-size: 0.68rem; font-weight: 600; padding: 2px 8px; border-radius: 9999px; }
.quick-title { font-size: 0.88rem; font-weight: 600; }
.quick-desc { font-size: 0.72rem; color: var(--text-tertiary); }
.quick-count { font-size: 0.75rem; color: var(--primary); font-weight: 600; }
.quick-card--hard.has-items { animation: hardPulse 2s ease-in-out infinite; }
@keyframes hardPulse { 0%, 100% { box-shadow: var(--shadow-sm); } 50% { box-shadow: 0px 4px 12px rgba(234,88,12,0.15); } }

/* ===== Modal (random practice) ===== */
.modal-overlay { position: fixed; inset: 0; background: rgba(15,23,42,0.5); backdrop-filter: blur(8px) saturate(180%); -webkit-backdrop-filter: blur(8px) saturate(180%); display: flex; align-items: center; justify-content: center; z-index: 9999; animation: fadeIn 150ms var(--ease-decelerate); }
.modal-overlay.js-hidden { display: none; }
@keyframes fadeIn { from { opacity: 0; } to { opacity: 1; } }

.modal-card { background: var(--surface); border-radius: 20px; padding: 28px 24px; max-width: 440px; width: 90%; box-shadow: var(--shadow-xl); animation: modalUp 300ms var(--ease-spring); }
@keyframes modalUp { from { opacity: 0; transform: translateY(16px) scale(0.97); } to { opacity: 1; transform: translateY(0) scale(1); } }

.modal-header { text-align: center; margin-bottom: 20px; }
.modal-header h3 { margin: 0 0 4px 0; font-size: 1.15rem; }
.modal-header p { margin: 0; font-size: 0.8rem; color: var(--text-tertiary); }

.modal-row-label { font-size: 0.78rem; font-weight: 600; color: var(--text-secondary); margin-bottom: 8px; }
.modal-presets { display: grid; grid-template-columns: repeat(5, 1fr); gap: 8px; margin-bottom: 16px; }
.modal-preset-btn { padding: 11px 6px; border: 2px solid var(--border); border-radius: 12px; background: var(--surface); color: var(--text-secondary); font-size: 0.82rem; font-weight: 600; transition: all var(--dur-fast) var(--ease-standard); min-height: 44px; }
.modal-preset-btn:hover { border-color: var(--primary); background: var(--primary-bg); color: var(--primary); transform: translateY(-1px); }
.modal-preset-btn:active { transform: scale(0.96); }

.modal-divider { display: flex; align-items: center; gap: 12px; margin: 16px 0; color: var(--text-tertiary); font-size: 0.75rem; }
.modal-divider::before, .modal-divider::after { content: ''; flex: 1; height: 1px; background: var(--border); }

.modal-custom { margin-bottom: 16px; }
.modal-custom label { display: block; font-size: 0.78rem; font-weight: 600; color: var(--text-secondary); margin-bottom: 8px; }
.modal-custom-row { display: flex; gap: 8px; }
.modal-input { flex: 1; padding: 11px 14px; border: 2px solid var(--border); border-radius: 12px; font-size: 0.88rem; outline: none; transition: all var(--dur-fast) var(--ease-standard); }
.modal-input:focus { border-color: var(--primary); box-shadow: 0 0 0 3px rgba(37,99,235,0.1); }
.modal-go-btn { padding: 11px 22px; background: var(--primary); color: #fff; border: none; border-radius: 12px; font-size: 0.85rem; font-weight: 600; white-space: nowrap; transition: all var(--dur-fast) var(--ease-standard); }
.modal-go-btn:hover { background: var(--primary-hover); box-shadow: 0 4px 12px rgba(37,99,235,0.3); transform: translateY(-1px); }

.modal-close-btn { display: block; width: 100%; padding: 11px; border: none; border-radius: 12px; background: var(--surface-variant); color: var(--text-secondary); font-size: 0.85rem; font-weight: 500; transition: all var(--dur-fast) var(--ease-standard); }
.modal-close-btn:hover { background: var(--border); color: var(--text); }

/* Switch toggle for timer */
.switch-row { display: flex; align-items: center; justify-content: space-between; padding: 12px 0; }
.switch-label { font-size: 0.82rem; font-weight: 600; color: var(--text-secondary); }
.switch-toggle { width: 44px; height: 24px; background: var(--border); border-radius: 9999px; position: relative; transition: background var(--dur-fast) var(--ease-standard); cursor: pointer; }
.switch-toggle::after { content: ''; position: absolute; top: 2px; left: 2px; width: 20px; height: 20px; background: #fff; border-radius: 50%; box-shadow: var(--shadow-sm); transition: transform var(--dur-normal) var(--ease-spring); }
.switch-toggle.active { background: var(--primary); }
.switch-toggle.active::after { transform: translateX(20px); }

/* ===== quiz/quiz.html — Practice Page ===== */

/* Progress bar (top) */
.quiz-progress-track--mb { margin-bottom: 16px; }
.quiz-progress-track--mb .quiz-progress-fill { transition: width 400ms var(--ease-decelerate); }

/* Resume card */
.resume-card { text-align: center; padding: 24px 20px; }
.resume-card .resume-icon { width: 64px; height: 64px; margin: 0 auto 12px; border-radius: 50%; background: var(--warning-bg); display: flex; align-items: center; justify-content: center; font-size: 1.8rem; }
.resume-card h3 { margin: 0 0 6px 0; font-size: 1.05rem; }
.resume-card p { font-size: 0.85rem; color: var(--text-tertiary); margin: 4px 0 18px 0; }
.resume-card .resume-actions { display: flex; gap: 10px; justify-content: center; flex-wrap: wrap; }
.resume-btn-primary { background: var(--primary); }
.resume-btn-reset { margin: 0; }

/* Question card */
.quiz-question-card { padding: clamp(16px, 3vw, 24px); }
.quiz-question-type { display: inline-block; padding: 3px 10px; border-radius: 9999px; font-size: 0.72rem; font-weight: 600; background: var(--primary-bg); color: var(--primary); margin-bottom: 10px; }
.quiz-difficulty-label { display: inline-block; padding: 3px 10px; border-radius: 9999px; font-size: 0.72rem; font-weight: 600; margin-left: 6px; }
.quiz-difficulty-label.diff-1 { background: #f0fdf4; color: #16a34a; }
.quiz-difficulty-label.diff-2 { background: #f0fdf4; color: #52c41a; }
.quiz-difficulty-label.diff-3 { background: #fffbeb; color: #faad14; }
.quiz-difficulty-label.diff-4 { background: #fff7ed; color: #ff7a45; }
.quiz-difficulty-label.diff-5 { background: #fef2f2; color: #f5222d; }

.quiz-question-text { font-size: clamp(0.95rem, 2vw, 1.05rem); font-weight: 500; line-height: 1.8; color: var(--text); margin-bottom: 16px; word-break: break-word; }

/* Options */
.quiz-options { display: flex; flex-direction: column; gap: 8px; }
.quiz-option { display: flex; align-items: center; gap: 10px; padding: 12px 16px; border: 1.5px solid var(--border); border-radius: 10px; cursor: pointer; transition: all var(--dur-fast) var(--ease-standard); font-size: 0.9rem; min-height: 48px; }
.quiz-option:hover { border-color: var(--primary); background: var(--primary-bg); transform: translateX(2px); }
.quiz-option:active { transform: scale(0.99); }
.quiz-option .opt-label { display: inline-flex; align-items: center; justify-content: center; width: 28px; height: 28px; border-radius: 50%; background: var(--surface-variant); color: var(--text-secondary); font-weight: 700; font-size: 0.8rem; flex-shrink: 0; transition: all var(--dur-fast) var(--ease-standard); }
.quiz-option:hover .opt-label { background: var(--primary-bg); color: var(--primary); }
.quiz-option.selected { border-color: var(--primary); background: var(--primary-bg); }
.quiz-option.selected .opt-label { background: var(--primary); color: #fff; }
.quiz-option.correct { border-color: var(--success-q); background: var(--success-bg); }
.quiz-option.correct .opt-label { background: var(--success-q); color: #fff; }
.quiz-option.wrong { border-color: var(--error-q); background: var(--error-bg); }
.quiz-option.wrong .opt-label { background: var(--error-q); color: #fff; }
.quiz-option.correct { animation: correctPulse 0.5s var(--ease-spring); }
@keyframes correctPulse { 0% { box-shadow: 0 0 0 0 rgba(22,163,74,0.4); } 50% { box-shadow: 0 0 0 8px rgba(22,163,74,0); } 100% { box-shadow: 0 0 0 0 rgba(22,163,74,0); } }
.quiz-option.locked { opacity: 0.5; pointer-events: none; }

/* Result feedback */
.quiz-result { margin-top: 14px; padding: 14px 16px; border-radius: 10px; font-size: 0.85rem; line-height: 1.7; animation: slideDown 300ms var(--ease-decelerate); }
@keyframes slideDown { from { opacity: 0; transform: translateY(-8px); } to { opacity: 1; transform: translateY(0); } }
.quiz-result.correct { background: var(--success-bg); border-left: 3px solid var(--success-q); color: #15803d; }
.quiz-result.wrong { background: var(--error-bg); border-left: 3px solid var(--error-q); color: #b91c1c; }
.quiz-result .result-icon { font-size: 1rem; margin-right: 4px; }
.explanation { margin-top: 8px; padding-top: 8px; border-top: 1px dashed var(--border); font-size: 0.82rem; color: var(--text-secondary); line-height: 1.6; }
.explanation .result-icon { color: var(--primary); }

/* Next button */
#nextBtn { margin-top: 20px; }
.next-btn-hidden { display: none; }

/* Grammar link in result */
.quiz-grammar-link { margin-top: 8px; }
.quiz-grammar-link a { color: var(--primary); font-size: 0.8rem; text-decoration: none; }
.quiz-grammar-link a:hover { text-decoration: underline; }

/* Similar questions */
.quiz-similar { margin-top: 12px; padding-top: 10px; border-top: 1px solid var(--border-light); }
.quiz-similar-title { font-size: 0.78rem; font-weight: 700; color: var(--text); margin-bottom: 6px; }
.quiz-similar-list { display: grid; gap: 6px; }
.quiz-similar-item { padding: 8px 10px; border: 1px solid var(--border-light); border-radius: 8px; background: var(--surface); }
.quiz-similar-meta { font-size: 0.72rem; color: var(--text-tertiary); line-height: 1.4; margin-bottom: 2px; }
.quiz-similar-question { font-size: 0.8rem; color: var(--text-secondary); line-height: 1.55; overflow-wrap: anywhere; }

/* Finish card */
.finish-card { text-align: center; padding: clamp(20px, 4vw, 32px); }
.quiz-finish-icon { font-size: 3rem; margin-bottom: 12px; animation: badgePop 500ms var(--ease-spring) both; }
@keyframes badgePop { from { opacity: 0; transform: scale(0.5); } to { opacity: 1; transform: scale(1); } }
.finish-card h2 { font-size: clamp(1.1rem, 2.5vw, 1.3rem); margin-bottom: 8px; }
.finish-stats-text { font-size: 0.88rem; color: var(--text-secondary); margin: 12px 0 16px; }

/* Finish SVG ring */
.finish-ring { width: 100px; height: 100px; margin: 0 auto 16px; }
.finish-ring circle.track { stroke: var(--border-light); stroke-width: 6; fill: none; }
.finish-ring circle.fill { stroke-width: 6; fill: none; stroke-linecap: round; transform: rotate(-90deg); transform-origin: center; transition: stroke-dashoffset 800ms var(--ease-decelerate); }
.finish-ring text { font-size: 24px; font-weight: 800; fill: var(--text); text-anchor: middle; dominant-baseline: central; }

.finish-stats { display: grid; grid-template-columns: repeat(4, 1fr); gap: 8px; margin: 16px 0 20px; }
.finish-stat { padding: 12px 8px; background: var(--surface-variant); border-radius: 10px; }
.finish-stat-num { font-size: clamp(1.1rem, 2.5vw, 1.4rem); font-weight: 800; }
.finish-stat-label { font-size: 0.7rem; color: var(--text-tertiary); margin-top: 2px; }
.finish-stat-num--total { color: var(--text); }
.finish-stat-num--correct { color: var(--success-q); }
.finish-stat-num--wrong { color: var(--error-q); }
.finish-stat-num--accuracy { color: var(--primary); }

/* Nav buttons */
.nav-btns { display: flex; gap: 10px; flex-wrap: wrap; justify-content: center; }
.nav-btns .nav-btn { display: inline-flex; align-items: center; gap: 4px; }
.nav-btn--wrong { background: var(--error-bg) !important; color: var(--error-q) !important; border-color: var(--error-border) !important; }
.nav-btn--wrong:hover { background: var(--error-q) !important; color: #fff !important; }

/* js-hidden utility */
.js-hidden { display: none !important; }

/* Responsive */
@media (max-width: 640px) {
  .page-header-inner { padding: 24px 0 20px; }
  .page-header h1 { font-size: 1.4rem; }
  .modal-presets { grid-template-columns: repeat(3, 1fr); }
  .finish-stats { grid-template-columns: repeat(2, 1fr); }
}

/* Reduced motion */
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { animation-duration: 0.01ms !important; animation-iteration-count: 1 !important; transition-duration: 0.01ms !important; }
}