:root {
  --sq-bg: #eef4f7;
  --sq-panel: #ffffff;
  --sq-ink: #132333;
  --sq-muted: #667789;
  --sq-line: #dce6ec;
  --sq-teal: #0d9488;
  --sq-indigo: #4f46e5;
  --sq-warm: #f59e0b;
  --sq-red: #dc2626;
  --sq-radius: 8px;
  --sq-shadow: 0 10px 30px rgba(15, 35, 52, 0.08);
}

* { box-sizing: border-box; }

body.spectraq-body {
  margin: 0;
  background: var(--sq-bg);
  color: var(--sq-ink);
  font-family: Inter, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
}

.spectraq-shell {
  min-height: 100vh;
  display: grid;
  grid-template-columns: 310px minmax(0, 1fr);
}

.sq-sidebar {
  background: #0b1724;
  color: #c8dce8;
  padding: 18px;
  overflow-y: auto;
  max-height: 100vh;
}

.sq-brand {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  padding-bottom: 16px;
  border-bottom: 1px solid rgba(255,255,255,0.08);
}

.sq-brand-mark {
  width: 38px;
  height: 38px;
  display: grid;
  place-items: center;
  border-radius: 8px;
  background: linear-gradient(135deg, var(--sq-teal), var(--sq-indigo));
  color: white;
  font-weight: 800;
}

.sq-brand h1 {
  margin: 0;
  font-size: 18px;
  line-height: 1;
}

.sq-brand span {
  display: block;
  margin-top: 4px;
  font-size: 11px;
  color: #7a9ab0;
}

.sq-home {
  color: #7a9ab0;
  text-decoration: none;
  font-size: 20px;
}

.sq-stats {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 8px;
  padding: 14px 0;
  border-bottom: 1px solid rgba(255,255,255,0.08);
}

.sq-stats div {
  border: 1px solid rgba(255,255,255,0.08);
  border-radius: 8px;
  padding: 9px 8px;
  background: rgba(255,255,255,0.035);
}

.sq-stats strong {
  display: block;
  color: white;
  font-size: 18px;
}

.sq-stats span {
  color: #6f91a7;
  font-size: 10px;
  text-transform: uppercase;
  letter-spacing: 0.8px;
}

.sq-level { margin-top: 18px; }

.sq-level-title {
  margin: 0 0 8px;
  font-size: 11px;
  letter-spacing: 1.2px;
  text-transform: uppercase;
  color: #5f8197;
}

.sq-lesson-btn {
  width: 100%;
  border: 0;
  text-align: left;
  color: #9eb8c8;
  background: transparent;
  border-left: 2px solid transparent;
  padding: 9px 10px;
  border-radius: 0 8px 8px 0;
  cursor: pointer;
}

.sq-lesson-btn:hover,
.sq-lesson-btn.active {
  background: rgba(13,148,136,0.12);
  color: #f8fbfc;
  border-left-color: var(--sq-teal);
}

.sq-lesson-btn.done strong::after {
  content: " ✓";
  color: #34d399;
}

.sq-lesson-btn.locked {
  opacity: 0.42;
  cursor: not-allowed;
}

.sq-lesson-btn strong {
  display: block;
  font-size: 13px;
  font-weight: 700;
}

.sq-lesson-btn span {
  display: block;
  margin-top: 3px;
  font-size: 11px;
  color: #6f91a7;
}

.sq-main { padding: 24px; }

.sq-menu-toggle {
  display: none;
  border: 1px solid #d4e0e8;
  background: white;
  color: #274057;
  border-radius: 8px;
  width: 40px;
  height: 40px;
  place-items: center;
  font-size: 20px;
}

.sq-overlay {
  display: none;
  position: fixed;
  inset: 0;
  background: rgba(4, 12, 22, 0.48);
  z-index: 900;
}

.sq-overlay.show {
  display: block;
}

.sq-audio-modal {
  display: none;
  position: fixed;
  inset: 0;
  z-index: 1200;
  background: rgba(4, 12, 22, 0.58);
  padding: 18px;
  align-items: center;
  justify-content: center;
}

.sq-audio-modal.show {
  display: flex;
}

.sq-audio-card {
  width: min(560px, 100%);
  background: white;
  border-radius: 10px;
  border: 1px solid var(--sq-line);
  box-shadow: 0 24px 70px rgba(0,0,0,0.26);
  padding: 16px;
  position: relative;
}

.sq-modal-close {
  position: absolute;
  top: 10px;
  right: 10px;
  width: 34px;
  height: 34px;
  border: 1px solid var(--sq-line);
  border-radius: 8px;
  background: white;
}

.sq-audio-card img {
  width: 100%;
  aspect-ratio: 16 / 9;
  object-fit: cover;
  border-radius: 8px;
  margin-bottom: 12px;
}

.sq-audio-card p {
  margin: 0 0 8px;
  color: var(--sq-muted);
}

.sq-audio-card h2 {
  margin: 0 0 14px;
  font-size: 24px;
}

.sq-topbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  margin-bottom: 18px;
}

.sq-kicker {
  margin: 0 0 6px;
  color: var(--sq-teal);
  font-size: 12px;
  font-weight: 800;
  letter-spacing: 1px;
  text-transform: uppercase;
}

.sq-topbar h2 {
  margin: 0;
  font-size: 26px;
  letter-spacing: 0;
}

.sq-topbar p {
  margin: 4px 0 0;
  color: var(--sq-muted);
}

.sq-progress {
  display: flex;
  align-items: center;
  gap: 10px;
  min-width: 240px;
}

.sq-progress-track {
  height: 8px;
  flex: 1;
  background: #d9e4ea;
  border-radius: 999px;
  overflow: hidden;
}

.sq-progress-fill {
  width: 0;
  height: 100%;
  background: linear-gradient(90deg, var(--sq-teal), var(--sq-indigo));
}

.sq-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 18px;
  align-items: start;
}

.sq-card {
  background: var(--sq-panel);
  border: 1px solid var(--sq-line);
  border-radius: var(--sq-radius);
  box-shadow: var(--sq-shadow);
}

.sq-stage { padding: 22px; }

.sq-part-tabs {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 8px;
  margin-bottom: 16px;
}

.sq-part-tab {
  border: 1px solid var(--sq-line);
  border-radius: var(--sq-radius);
  background: #f8fbfc;
  color: #274057;
  padding: 10px 12px;
  text-align: left;
  cursor: pointer;
}

.sq-part-tab strong,
.sq-part-tab span {
  display: block;
}

.sq-part-tab strong {
  font-size: 14px;
}

.sq-part-tab span {
  margin-top: 2px;
  font-size: 11px;
  color: var(--sq-muted);
}

.sq-part-tab:hover,
.sq-part-tab.active {
  border-color: var(--sq-teal);
  background: #ecfdf5;
  color: #0f766e;
}

.sq-part-tab.done {
  border-color: #34d399;
  background: #f0fdf4;
  color: #15803d;
}

.sq-part-tab.done strong::after {
  content: " ✓";
  color: #15803d;
}

.sq-part-tab.active span {
  color: #0f766e;
}

.sq-step-head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  color: var(--sq-muted);
  font-size: 13px;
  margin-bottom: 16px;
}

.sq-step-head strong {
  color: var(--sq-teal);
  text-transform: uppercase;
  letter-spacing: 0.9px;
  font-size: 12px;
}

.sq-prompt-card {
  display: none;
}

.sq-prompt-card p {
  margin: 0 0 8px;
  color: var(--sq-muted);
}

.sq-prompt-card h1 {
  margin: 0;
  font-size: 34px;
  line-height: 1.15;
  letter-spacing: 0;
}

.sq-model-line {
  border: 1px solid #cfdbe3;
  background: white;
  border-radius: var(--sq-radius);
  padding: 16px;
  font-size: 22px;
  margin-bottom: 14px;
}

.sq-video-card {
  position: relative;
  overflow: hidden;
  border: 1px solid var(--sq-line);
  border-radius: var(--sq-radius);
  margin-bottom: 12px;
  background: #0b1724;
}

.sq-video-card img {
  width: 100%;
  aspect-ratio: 16 / 9;
  object-fit: cover;
  display: block;
}

.sq-video-overlay {
  position: absolute;
  inset: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  flex-direction: column;
  gap: 8px;
  background: linear-gradient(180deg, rgba(4, 12, 22, 0.04), rgba(4, 12, 22, 0.42));
  color: white;
  font-weight: 800;
}

.sq-presentation-player {
  border: 1px solid var(--sq-line);
  border-radius: var(--sq-radius);
  background: #ffffff;
  overflow: hidden;
  box-shadow: 0 16px 34px rgba(22, 50, 70, 0.12);
}

.sq-presentation-player img {
  width: 100%;
  aspect-ratio: 16 / 9;
  object-fit: cover;
  display: block;
}

.sq-presentation-copy {
  padding: 18px;
}

.sq-presentation-copy > span {
  display: inline-flex;
  align-items: center;
  min-height: 28px;
  padding: 4px 9px;
  border-radius: 999px;
  background: #ecfeff;
  color: #0f766e;
  font-weight: 850;
  margin-bottom: 10px;
}

.sq-presentation-copy h2 {
  margin: 0 0 10px;
  color: #102033;
  font-size: clamp(24px, 4vw, 38px);
  line-height: 1.12;
  letter-spacing: 0;
}

.sq-presentation-copy p {
  margin: 0 0 14px;
  color: #0f766e;
  font-size: clamp(20px, 3vw, 30px);
  font-weight: 850;
  line-height: 1.2;
}

.sq-video-play {
  width: 64px;
  height: 64px;
  border: 0;
  border-radius: 999px;
  display: grid;
  place-items: center;
  color: white;
  background: var(--sq-teal);
  font-size: 34px;
  box-shadow: 0 14px 30px rgba(0,0,0,0.28);
  cursor: pointer;
}

.sq-item-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 12px;
}

.sq-item-card {
  border: 1px solid var(--sq-line);
  background: white;
  border-radius: var(--sq-radius);
  padding: 10px;
  text-align: left;
  cursor: pointer;
}

.sq-reveal {
  opacity: 0;
  transform: translateY(22px) scale(0.94);
  filter: blur(8px);
  animation: sqRevealIn 0.62s cubic-bezier(0.2, 0.9, 0.22, 1.12) forwards;
  will-change: opacity, transform, filter;
}

@keyframes sqRevealIn {
  0% {
    opacity: 0;
    transform: translateY(22px) scale(0.94);
    filter: blur(8px);
    box-shadow: 0 0 0 rgba(20, 184, 166, 0);
  }
  62% {
    opacity: 1;
    transform: translateY(-4px) scale(1.018);
    filter: blur(0);
    box-shadow: 0 18px 34px rgba(20, 184, 166, 0.16);
  }
  to {
    opacity: 1;
    transform: translateY(0) scale(1);
    filter: blur(0);
    box-shadow: 0 0 0 rgba(20, 184, 166, 0);
  }
}

@media (prefers-reduced-motion: reduce) {
  .sq-reveal {
    opacity: 1;
    transform: none;
    filter: none;
    animation: none;
  }
}

.sq-item-card:hover {
  border-color: var(--sq-teal);
}

.sq-item-card img,
.sq-choice-item img,
.sq-pronunciation-row img,
.sq-substitution-card img,
.sq-order-item img,
.sq-writing-item img,
.sq-final-card img {
  width: 100%;
  aspect-ratio: 16 / 9;
  object-fit: cover;
  border-radius: 7px;
  margin-bottom: 8px;
  background: #e5eef3;
}

.sq-item-card img,
.sq-choice-item img,
.sq-substitution-card img,
.sq-order-item img,
.sq-writing-item img,
.sq-final-card img {
  box-shadow: inset 0 0 0 1px rgba(19,35,51,0.05);
}

.sq-item-card strong,
.sq-item-card span,
.sq-item-card small {
  display: block;
}

.sq-item-card strong {
  font-size: 15px;
  margin-bottom: 3px;
}

.sq-item-card span {
  color: var(--sq-muted);
  font-size: 13px;
}

.sq-item-card small {
  color: var(--sq-teal);
  font-weight: 800;
  margin-top: 7px;
}

.sq-choice-by-item,
.sq-pronunciation-list,
.sq-substitution-list,
.sq-order-list,
.sq-writing-list,
.sq-final-exam,
.sq-reading-questions,
.sq-dialogue-b-list {
  display: grid;
  gap: 12px;
}

.sq-choice-item,
.sq-order-item,
.sq-writing-item,
.sq-final-card,
.sq-reading-question,
.sq-dialogue-practice {
  border: 1px solid var(--sq-line);
  border-radius: var(--sq-radius);
  padding: 12px;
  background: #f8fbfc;
}

.sq-order-item,
.sq-writing-item,
.sq-final-card {
  display: grid;
  gap: 10px;
}

.sq-choice-item-head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 10px;
  margin-bottom: 8px;
}

.sq-audio-pair {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  justify-content: flex-end;
}

.sq-mini-audio {
  border: 1px solid #cfdbe3;
  border-radius: 8px;
  background: var(--sq-teal);
  color: white;
  min-height: 38px;
  padding: 8px 10px;
  font-weight: 800;
  display: inline-flex;
  align-items: center;
  gap: 6px;
}

.sq-choice-list.compact {
  grid-template-columns: 1fr;
}

.sq-pronunciation-row {
  display: grid;
  grid-template-columns: 140px minmax(0, 1fr) 86px;
  gap: 12px;
  align-items: center;
  border: 1px solid var(--sq-line);
  border-radius: var(--sq-radius);
  padding: 10px;
  background: #f8fbfc;
}

.sq-substitution-card {
  display: grid;
  grid-template-columns: 140px minmax(0, 1fr) 86px;
  gap: 12px;
  align-items: center;
  border: 1px solid var(--sq-line);
  border-radius: var(--sq-radius);
  padding: 10px;
  background: #f8fbfc;
}

.sq-pronunciation-row img,
.sq-substitution-card img {
  margin-bottom: 0;
}

.sq-pronunciation-row strong,
.sq-pronunciation-row span,
.sq-pronunciation-row em,
.sq-substitution-card strong,
.sq-substitution-card span,
.sq-substitution-card small,
.sq-substitution-card em {
  display: block;
}

.sq-pronunciation-row em,
.sq-substitution-card em {
  color: var(--sq-indigo);
  font-style: normal;
  font-weight: 800;
  margin-bottom: 4px;
}

.sq-pronunciation-row span,
.sq-substitution-card small {
  color: var(--sq-muted);
  margin: 3px 0 8px;
}

.sq-hint {
  width: fit-content;
  border: 1px solid #b9e8e1;
  border-radius: var(--sq-radius);
  background: #ecfeff;
  color: #0f766e;
  font-weight: 800;
  padding: 8px 10px;
  margin: 8px 0;
}

.sq-review-answer {
  margin: 2px 0 10px;
  padding: 10px 12px;
  border: 1px solid #bfdbfe;
  border-radius: var(--sq-radius);
  background: #eff6ff;
}

.sq-review-answer span {
  display: block;
  margin: 0 0 2px;
  color: #64748b;
  font-size: 11px;
  font-weight: 850;
  text-transform: uppercase;
}

.sq-review-answer strong {
  display: block;
  color: #1d4ed8;
  margin-bottom: 7px;
}

.sq-review-answer strong:last-child {
  margin-bottom: 0;
  color: #0f766e;
}

.sq-repeat-state {
  color: var(--sq-muted);
  font-size: 12px;
  text-align: center;
}

.sq-pronunciation-row.done,
.sq-substitution-card.done,
.sq-order-item.done,
.sq-writing-item.done,
.sq-final-card.done,
.sq-dialogue-practice.done {
  border-color: #34d399;
  background: #f0fdf4;
}

.sq-order-item.wrong,
.sq-writing-item.wrong {
  border-color: #f87171;
  background: #fff1f2;
}

.sq-pronunciation-row.done .sq-repeat-state,
.sq-substitution-card.done .sq-repeat-state,
.sq-order-item.done .sq-item-state,
.sq-writing-item.done .sq-item-state,
.sq-final-card.done .sq-repeat-state,
.sq-dialogue-practice.done .sq-repeat-state {
  color: #15803d;
}

.sq-reading-card,
.sq-dialogue-card,
.sq-dialogue-final {
  border: 1px solid var(--sq-line);
  border-radius: var(--sq-radius);
  background: #ffffff;
  padding: 14px;
  margin-bottom: 12px;
}

.sq-reading-card {
  display: grid;
  grid-template-columns: minmax(220px, 36%) minmax(0, 1fr);
  gap: 16px;
  align-items: start;
}

.sq-reading-card img,
.sq-dialogue-card img {
  width: 100%;
  aspect-ratio: 16 / 10;
  object-fit: cover;
  border-radius: var(--sq-radius);
  border: 1px solid var(--sq-line);
}

.sq-reading-copy {
  display: grid;
  gap: 10px;
}

.sq-reading-copy p {
  margin: 0;
  color: #26394b;
  font-size: 15px;
  line-height: 1.6;
}

.sq-reading-question {
  display: grid;
  gap: 10px;
}

.sq-reading-question > strong {
  color: var(--sq-ink);
  font-size: 15px;
}

.sq-dialogue-card {
  display: grid;
  grid-template-columns: minmax(200px, 32%) minmax(0, 1fr);
  gap: 16px;
}

.sq-dialogue-toolbar {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-bottom: 12px;
}

.sq-dialogue-lines {
  display: grid;
  gap: 7px;
}

.sq-dialogue-line {
  display: grid;
  grid-template-columns: 34px minmax(0, 1fr);
  gap: 8px;
  align-items: start;
}

.sq-dialogue-line b {
  display: grid;
  place-items: center;
  min-height: 28px;
  border-radius: 8px;
  background: #e0f2fe;
  color: #0369a1;
  font-size: 12px;
}

.sq-dialogue-line.speaker-b b {
  background: #ccfbf1;
  color: #0f766e;
}

.sq-dialogue-line span {
  border: 1px solid var(--sq-line);
  border-radius: var(--sq-radius);
  background: #f8fbfc;
  padding: 8px 10px;
  line-height: 1.35;
}

.sq-dialogue-final h3 {
  margin: 0 0 4px;
  font-size: 18px;
}

.sq-dialogue-final > p {
  margin: 0 0 12px;
  color: var(--sq-muted);
}

.sq-dialogue-practice {
  display: grid;
  grid-template-columns: minmax(180px, 1fr) minmax(220px, auto) minmax(110px, 150px) 80px;
  gap: 10px;
  align-items: center;
}

.sq-dialogue-practice span {
  display: block;
  color: var(--sq-indigo);
  font-size: 12px;
  font-weight: 850;
  margin-bottom: 3px;
}

.sq-dialogue-practice strong {
  display: block;
  line-height: 1.35;
}

.sq-dialogue-practice details {
  color: var(--sq-muted);
  font-size: 13px;
}

.sq-dialogue-practice summary {
  cursor: pointer;
  font-weight: 800;
  color: var(--sq-teal);
}

.sq-dialogue-practice details p {
  margin: 6px 0 0;
  color: var(--sq-ink);
}

.sq-order-item.wrong .sq-item-state,
.sq-writing-item.wrong .sq-item-state {
  color: #b91c1c;
}

.sq-item-state {
  color: var(--sq-muted);
  font-size: 12px;
}

.sq-presentation {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 10px;
  margin-bottom: 12px;
}

.sq-presentation div {
  border: 1px solid var(--sq-line);
  border-radius: var(--sq-radius);
  background: #f8fbfc;
  padding: 12px;
}

.sq-presentation span,
.sq-presentation strong {
  display: block;
}

.sq-presentation span {
  color: var(--sq-muted);
  font-size: 11px;
  text-transform: uppercase;
  letter-spacing: 0.8px;
  margin-bottom: 4px;
}

.sq-presentation strong {
  color: var(--sq-ink);
  font-size: 14px;
}

.sq-answer {
  width: 100%;
  min-height: 112px;
  border: 1px solid #cad7df;
  border-radius: var(--sq-radius);
  padding: 12px;
  resize: vertical;
  font: inherit;
  color: var(--sq-ink);
  margin-bottom: 12px;
}

.sq-writing-label {
  color: var(--sq-muted);
  font-size: 12px;
  font-weight: 800;
  text-transform: uppercase;
}

.sq-writing-item .sq-answer {
  min-height: 78px;
  margin-bottom: 4px;
}

.sq-sentence-hint {
  border: 1px solid #b9e8e1;
  border-radius: var(--sq-radius);
  background: #ecfeff;
  color: #0f766e;
  font-weight: 800;
  padding: 10px 12px;
}

.sq-sentence-hint strong,
.sq-sentence-hint span {
  display: block;
}

.sq-sentence-hint span {
  margin-top: 4px;
}

.sq-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-bottom: 16px;
}

.sq-nav-actions {
  justify-content: space-between;
  margin-bottom: 0;
  position: sticky;
  bottom: 0;
  z-index: 12;
  padding: 12px 0 0;
  background: linear-gradient(180deg, rgba(255, 255, 255, 0), var(--sq-panel) 32%);
}

.sq-btn {
  border: 1px solid transparent;
  border-radius: var(--sq-radius);
  padding: 10px 13px;
  font-weight: 800;
  cursor: pointer;
  display: inline-flex;
  align-items: center;
  gap: 8px;
}

.sq-btn.primary { background: var(--sq-teal); color: white; }
.sq-btn.secondary { background: #eef4f7; color: #274057; border-color: #d4e0e8; }
.sq-btn.explanation { background: #fff7ed; color: #9a3412; border-color: #fed7aa; }
.sq-btn.explanation:hover { background: #ffedd5; }
.sq-btn.success-loading,
.sq-btn.success-loading:disabled {
  background: #16a34a;
  color: white;
  border-color: #16a34a;
  opacity: 1;
}
.sq-btn.warn { background: #fff7e6; color: #8a5700; border-color: #f4d48b; }
.sq-btn.needs-speaking { background: #fff7e6; color: #8a5700; border-color: #f4d48b; }
.sq-btn.spoken-ok { background: #16a34a; color: white; border-color: #16a34a; }
.sq-btn.recording { background: var(--sq-red); color: white; }
.sq-btn:disabled { opacity: 0.45; cursor: not-allowed; }

.sq-spin {
  animation: sq-spin 0.72s linear infinite;
}

@keyframes sq-spin {
  to { transform: rotate(360deg); }
}

.sq-feedback {
  min-height: 52px;
  border: 1px solid var(--sq-line);
  background: #f8fbfc;
  border-radius: var(--sq-radius);
  padding: 12px;
  color: var(--sq-muted);
  margin: 16px 0;
}

.sq-slot-grid,
.sq-choice-list {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 9px;
  margin-bottom: 12px;
}

.sq-slot,
.sq-choice {
  border: 1px solid #d4e0e8;
  background: white;
  color: #274057;
  border-radius: var(--sq-radius);
  padding: 11px;
  cursor: pointer;
  text-align: left;
}

.sq-slot:hover,
.sq-choice:hover,
.sq-choice.selected {
  border-color: var(--sq-teal);
  color: var(--sq-teal);
  background: #f0fdfa;
}

.sq-choice.correct {
  border-color: #16a34a;
  color: #15803d;
  background: #f0fdf4;
}

.sq-choice.wrong {
  border-color: #ef4444;
  color: #b91c1c;
  background: #fff1f2;
}

.sq-word-bank {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-bottom: 12px;
}

.sq-word {
  border: 1px solid #d4e0e8;
  background: #f7fafb;
  border-radius: 999px;
  padding: 8px 11px;
  cursor: pointer;
}

.sq-explain-shell {
  width: min(1120px, calc(100% - 28px));
  margin: 0 auto;
  padding: 24px 0 48px;
}

.sq-explain-nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 14px;
  margin-bottom: 18px;
  color: var(--sq-muted);
  font-weight: 700;
}

.sq-explain-hero {
  background:
    linear-gradient(135deg, rgba(13, 148, 136, 0.14), rgba(79, 70, 229, 0.12)),
    var(--sq-panel);
  border: 1px solid var(--sq-line);
  border-radius: var(--sq-radius);
  box-shadow: var(--sq-shadow);
  padding: 28px;
  margin-bottom: 18px;
}

.sq-explain-hero h1 {
  margin: 4px 0 8px;
  font-size: clamp(28px, 4vw, 46px);
  line-height: 1.05;
  letter-spacing: 0;
}

.sq-explain-hero p {
  margin: 0;
  color: #355063;
  font-size: 17px;
}

.sq-explain-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 9px;
  margin-top: 18px;
}

.sq-explain-tags span {
  display: inline-flex;
  align-items: center;
  min-height: 34px;
  padding: 7px 11px;
  border-radius: 999px;
  background: #ecfeff;
  border: 1px solid #a5f3fc;
  color: #155e75;
  font-weight: 800;
}

.sq-explain-grid {
  display: grid;
  grid-template-columns: minmax(0, 1.4fr) minmax(280px, 0.6fr);
  gap: 18px;
  align-items: start;
}

.sq-explain-panel {
  background: var(--sq-panel);
  border: 1px solid var(--sq-line);
  border-radius: var(--sq-radius);
  box-shadow: var(--sq-shadow);
  padding: 22px;
  margin-bottom: 18px;
}

.sq-explain-panel h2 {
  margin: 0 0 16px;
  font-size: 22px;
  letter-spacing: 0;
}

.sq-rule-block {
  border-left: 5px solid var(--sq-teal);
  background: #f8fafc;
  padding: 14px 16px;
  margin-bottom: 12px;
}

.sq-rule-block:nth-child(odd) {
  border-left-color: #4f46e5;
}

.sq-rule-block h3 {
  margin: 0 0 7px;
  color: #0f766e;
  font-size: 18px;
}

.sq-rule-block p {
  margin: 0;
  color: #243849;
  line-height: 1.55;
}

.sq-rule-block b {
  color: #4f46e5;
}

.sq-rule-block mark {
  background: #fef3c7;
  color: #92400e;
  padding: 2px 5px;
  border-radius: 5px;
}

.sq-practice-list {
  margin: 0;
  padding: 0;
  list-style: none;
  display: grid;
  gap: 10px;
}

.sq-practice-list li {
  padding: 12px;
  background: #f0fdfa;
  border: 1px solid #99f6e4;
  border-radius: var(--sq-radius);
  color: #134e4a;
  font-weight: 700;
}

.sq-grammar-sections {
  display: grid;
  gap: 16px;
}

.sq-grammar-section {
  border: 1px solid #dbe6ee;
  border-radius: var(--sq-radius);
  background: linear-gradient(180deg, #ffffff, #f8fafc);
  padding: 18px;
}

.sq-grammar-section h3 {
  margin: 0 0 10px;
  color: #4338ca;
  font-size: 21px;
  letter-spacing: 0;
}

.sq-grammar-section p {
  margin: 0 0 14px;
  color: #23384a;
  font-size: 16px;
  line-height: 1.68;
}

.sq-grammar-section ul {
  margin: 0;
  padding: 0;
  list-style: none;
  display: grid;
  gap: 9px;
}

.sq-grammar-section li {
  position: relative;
  padding: 11px 12px 11px 38px;
  border-radius: 8px;
  background: #eef6ff;
  color: #17324d;
  line-height: 1.45;
}

.sq-grammar-section li::before {
  content: "";
  position: absolute;
  left: 14px;
  top: 17px;
  width: 9px;
  height: 9px;
  border-radius: 99px;
  background: #0d9488;
}

.sq-grammar-section b {
  color: #4f46e5;
}

.sq-grammar-section mark {
  background: #fef3c7;
  color: #92400e;
  padding: 2px 5px;
  border-radius: 5px;
}

.sq-grammar-section i {
  color: #b91c1c;
}

.sq-grammar-page {
  width: min(900px, calc(100% - 28px));
  margin: 0 auto;
  padding: 24px 0 56px;
}

.sq-grammar-nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 14px;
  margin-bottom: 28px;
  color: var(--sq-muted);
  font-weight: 800;
}

.sq-grammar-article {
  background: transparent;
}

.sq-grammar-article h1 {
  margin: 0 0 24px;
  color: #102033;
  font-size: clamp(34px, 5vw, 58px);
  line-height: 1.03;
  letter-spacing: 0;
}

.sq-grammar-article p {
  margin: 0 0 22px;
  color: #22384b;
  font-size: 19px;
  line-height: 1.78;
}

.sq-grammar-article p:first-of-type {
  color: #0f766e;
  font-size: 21px;
  font-weight: 750;
}

.sq-example-list {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 12px;
}

.sq-example-row {
  display: grid;
  grid-template-columns: 110px minmax(0, 1fr);
  gap: 12px;
  align-items: center;
  background: #f8fafc;
  border: 1px solid #dbe6ee;
  border-radius: var(--sq-radius);
  padding: 10px;
}

.sq-example-row img {
  width: 110px;
  aspect-ratio: 1;
  object-fit: cover;
  border-radius: 8px;
}

.sq-example-row span {
  display: block;
  color: var(--sq-muted);
  font-size: 12px;
  font-weight: 800;
  text-transform: uppercase;
}

.sq-example-row strong {
  display: block;
  color: #1d4ed8;
  margin: 2px 0 8px;
}

.sq-example-row p {
  margin: 2px 0 0;
  color: #0f766e;
  font-weight: 800;
}

.sq-word:disabled {
  opacity: 0.4;
  cursor: not-allowed;
}

.sq-built {
  min-height: 50px;
  border: 1px dashed #b9c9d3;
  border-radius: var(--sq-radius);
  padding: 12px;
  color: #33495c;
}

.sq-side {
  display: none;
  overflow: hidden;
}

.sq-side img {
  width: 100%;
  aspect-ratio: 16 / 10;
  object-fit: cover;
  display: block;
}

.sq-side-body { padding: 16px; }

.sq-chip-row {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-bottom: 14px;
}

.sq-chip {
  border: 1px solid #cfdbe3;
  background: #f7fafb;
  border-radius: 999px;
  padding: 6px 10px;
  color: var(--sq-muted);
  font-size: 12px;
}

.sq-side h3 {
  margin: 8px 0 10px;
  font-size: 15px;
}

.sq-history {
  display: grid;
  gap: 8px;
}

.sq-history p {
  color: var(--sq-muted);
  margin: 0;
}

.sq-history-row {
  border: 1px solid var(--sq-line);
  border-radius: var(--sq-radius);
  padding: 10px;
  background: #f8fbfc;
}

.sq-history-row strong,
.sq-history-row span {
  display: block;
}

.sq-history-row span {
  color: var(--sq-muted);
  font-size: 12px;
  margin-top: 3px;
}

@media (max-width: 980px) {
  .spectraq-shell {
    display: block;
  }
  .sq-sidebar {
    position: fixed;
    top: 0;
    left: 0;
    width: 310px;
    height: 100vh;
    max-height: 100vh;
    z-index: 1000;
    transform: translateX(-100%);
    transition: transform 0.24s ease;
    overflow-y: auto;
  }
  .sq-sidebar.open {
    transform: translateX(0);
  }
  .sq-menu-toggle {
    display: inline-grid;
    margin-bottom: 8px;
  }
  .sq-grid { grid-template-columns: 1fr; }
  .sq-explain-grid,
  .sq-example-list {
    grid-template-columns: 1fr;
  }
  .sq-topbar {
    align-items: flex-start;
    flex-direction: column;
  }
  .sq-progress { width: 100%; }
}

@media (max-width: 560px) {
  .sq-sidebar {
    padding: 12px 14px;
    width: min(310px, 84vw);
  }
  .sq-brand {
    padding-bottom: 10px;
  }
  .sq-brand-mark {
    width: 34px;
    height: 34px;
  }
  .sq-brand h1 {
    font-size: 17px;
  }
  .sq-stats {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 6px;
    padding: 10px 0;
  }
  .sq-stats div {
    padding: 7px 8px;
  }
  .sq-stats strong {
    font-size: 16px;
  }
  .sq-level {
    margin-top: 10px;
  }
  .sq-level-title {
    font-size: 10px;
    min-height: 24px;
    margin-bottom: 6px;
  }
  .sq-lesson-btn {
    padding: 7px 9px;
    min-height: 58px;
  }
  .sq-lesson-btn strong {
    font-size: 12px;
  }
  .sq-lesson-btn span {
    font-size: 10px;
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
    overflow: hidden;
  }
  .sq-main {
    padding: 12px;
  }
  .sq-topbar {
    gap: 8px;
    margin-bottom: 10px;
  }
  .sq-topbar h2 {
    font-size: 22px;
  }
  .sq-topbar p {
    font-size: 14px;
  }
  .sq-progress {
    min-width: 0;
  }
  .sq-stage {
    padding: 12px;
  }
  .sq-part-tabs {
    grid-template-columns: 1fr;
    gap: 7px;
  }
  .sq-part-tab {
    display: flex;
    justify-content: space-between;
    align-items: center;
  }
  .sq-part-tab span {
    margin-top: 0;
  }
  .sq-step-head {
    margin-bottom: 10px;
  }
  .sq-model-line { font-size: 18px; }
  .sq-presentation {
    grid-template-columns: 1fr;
  }
  .sq-answer {
    min-height: 92px;
  }
  .sq-feedback {
    margin: 12px 0;
    min-height: 44px;
  }
  .sq-actions {
    gap: 8px;
  }
  .sq-nav-actions {
    display: grid;
    grid-template-columns: 1fr 1fr;
  }
  .sq-nav-actions .sq-btn {
    justify-content: center;
    min-height: 44px;
  }
  .sq-nav-actions #nextBtn {
    grid-column: 1 / -1;
  }
  .sq-btn {
    padding: 9px 11px;
  }
  .sq-side {
    display: none;
  }
  .sq-slot-grid,
  .sq-choice-list { grid-template-columns: 1fr; }
  .sq-item-grid {
    grid-template-columns: 1fr;
  }
  .sq-pronunciation-row,
  .sq-substitution-card {
    grid-template-columns: 1fr;
  }
  .sq-reading-card,
  .sq-dialogue-card,
  .sq-dialogue-practice {
    grid-template-columns: 1fr;
  }
  .sq-repeat-state {
    text-align: left;
  }
}