/* ═══════════════════════════════════════════════════════════════════════════
   learning-hub.css — Shared hub layout for all scene drill pages
   ═══════════════════════════════════════════════════════════════════════════ */

/* ── Shared: card ──────────────────────────────────────────────────── */

.ls-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 14px;
  padding: clamp(16px, 2.5vh, 28px);
  transition: border-color 0.2s, box-shadow 0.2s;
}


/* ══════════════════════════════════════════════════════════════════════
   LEARNING SPACE HUB
   ══════════════════════════════════════════════════════════════════════ */

#screen-hub {
  padding-top: clamp(16px, 2.5vh, 28px);
  width: 100%;
  max-width: 860px;
}
.hub-title {
  font-family: 'Noto Serif SC', serif;
  font-size: clamp(1.6rem, 3.5vh, 2.2rem);
  font-weight: 800;
  color: var(--text);
  text-align: center;
  margin-bottom: clamp(14px, 2.5vh, 24px);
}
.hub-title-zh {
  color: var(--t4, #4d9de0);
}
.hub-title-en {
  font-family: 'DM Sans', sans-serif;
  font-weight: 700;
  color: #ffffff;
}
.hub-scene-subtitle-row {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  margin-top: 0;
  margin-bottom: clamp(10px, 2vh, 20px);
}
.hub-scene-subtitle {
  text-align: center;
  font-size: clamp(1.6rem, 3.5vh, 2.2rem);
  font-weight: 800;
  color: #ffffff;
  letter-spacing: 0.5px;
}
.hub-replay-intro-btn {
  background: none;
  border: 1.5px solid var(--border);
  color: var(--muted);
  font-size: 0.78rem;
  padding: 4px 10px;
  border-radius: 6px;
  cursor: pointer;
  white-space: nowrap;
  transition: color 0.15s, border-color 0.15s;
}
.hub-replay-intro-btn:hover {
  color: var(--primary);
  border-color: var(--primary);
}

/* Phase forward/back nav row */
.phase-nav-row {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 12px 16px;
  max-width: 600px;
  margin: 0 auto;
}
.phase-nav-btn {
  background: none;
  border: 1.5px solid var(--border);
  color: var(--fg);
  font-size: 0.85rem;
  padding: 8px 18px;
  border-radius: 8px;
  cursor: pointer;
  transition: background 0.15s, border-color 0.15s;
}
.phase-nav-btn:hover {
  background: rgba(255,255,255,0.06);
  border-color: var(--primary);
  color: var(--primary);
}

.hub-top {
  display: grid;
  grid-template-columns: 1fr 1fr;
  align-items: start;
  gap: clamp(12px, 2vw, 20px);
  margin-bottom: clamp(16px, 2.5vh, 24px);
}
.hub-top > .ls-card {
  padding: clamp(10px, 1.6vh, 16px);
}

/* Progress frame */
.progress-frame {
  display: flex;
  flex-direction: column;
  gap: 4px;
  background: #fdf6ec !important;
  border-color: #1a1a1a !important;
}

.progress-scene-title {
  font-size: clamp(0.88rem, 1.5vh, 1.05rem);
  font-weight: 800;
  color: #1a1a1a !important;
  text-align: center;
  margin-bottom: 2px;
}
.progress-unlock-hint {
  font-family: 'DM Sans', sans-serif;
  font-size: clamp(0.71rem, 1.05vh, 0.82rem);
  font-weight: 400;
  color: rgba(0,0,0,0.55);
  text-align: center;
  margin-top: 4px;
  margin-bottom: 0;
}
.progress-cols {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 0;
}

.progress-scene-num {
  font-size: clamp(0.9rem, 1.25vh, 1.06rem);
  color: #1a1a1a;
  letter-spacing: 1px;
  text-transform: uppercase;
}

.progress-cups {
  display: flex;
  flex-direction: column;
  gap: 2px;
  margin-top: 2px;
}

.progress-cup-row {
  display: flex;
  align-items: center;
  gap: 6px;
  font-size: clamp(0.78rem, 1.2vh, 0.92rem);
  color: #1a1a1a;
}

.progress-cup-row .cup-icon {
  width: 24px;
  height: 24px;
  flex-shrink: 0;
}

.progress-cup-row .cup-label {
}

.progress-cup-row .cup-pct {
  font-size: clamp(0.72rem, 1.0vh, 0.84rem);
  color: #1a1a1a;
  font-weight: 600;
  min-width: 32px;
  text-align: right;
}

/* Cup fill animation */
.cup-liquid {
  transition: height 0.6s ease-out, y 0.6s ease-out;
}

/* Gold shimmer on 100% cup */
@keyframes cup-gold-shimmer {
  0%, 100% { filter: drop-shadow(0 0 0 transparent); }
  50% { filter: drop-shadow(0 0 4px rgba(255,217,61,0.5)); }
}
.cup-icon.cup-full {
  animation: cup-gold-shimmer 2s ease-in-out infinite;
}

/* Steam animation for 100% cup */
@keyframes cup-steam {
  0% { opacity: 0; transform: translateY(0); }
  40% { opacity: 0.6; }
  100% { opacity: 0; transform: translateY(-6px); }
}
.cup-steam-line {
  animation: cup-steam 1.8s ease-out infinite;
}
.cup-steam-line:nth-child(2) { animation-delay: 0.4s; }
.cup-steam-line:nth-child(3) { animation-delay: 0.8s; }

/* Scene snapshot (right) */
.scene-snapshot {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 4px;
}

.scene-img-wrap {
  position: relative;
  width: 100%;
  border-radius: 0;
  overflow: hidden;
  border: none;
  transition: border-color 0.25s ease, box-shadow 0.25s ease, transform 0.2s ease;
}
.scene-snapshot img {
  width: 100%;
  aspect-ratio: 4 / 3;
  display: block;
  object-fit: cover;
}
.scene-img-overlay {
  position: absolute;
  inset: 0;
  background: var(--surface);
  transition: opacity 0.6s ease;
  pointer-events: none;
}

/* Progress bar overlaid on scene image */
.scene-progress-wrap {
  position: absolute;
  bottom: 0;
  left: 0;
  right: 0;
  padding: 6px 8px 5px;
  background: rgba(0,0,0,0.55);
  display: flex;
  flex-direction: column;
  gap: 3px;
  z-index: 2;
}
.scene-progress-track {
  width: 100%;
  height: 5px;
  border-radius: 3px;
  background: rgba(255,255,255,0.2);
  overflow: hidden;
}
.scene-progress-fill {
  height: 100%;
  border-radius: 3px;
  background: linear-gradient(90deg, var(--t4), #6a5acd);
  width: 0%;
  transition: width 0.6s ease;
}
.scene-progress-label {
  font-size: clamp(0.6rem, 0.85vh, 0.72rem);
  color: rgba(255,255,255,0.8);
  text-align: center;
  letter-spacing: 0.5px;
}

/* Scene image — neon blue hover when unlocked */
.scene-img-wrap[style*="pointer"]:hover {
  border-color: #4d9de0;
  box-shadow: 0 0 14px rgba(77,157,224,0.5);
  transform: scale(1.02);
}

/* Enter scene button — shown when all 4 skills passed */
.scene-enter-btn {
  display: block;
  width: 100%;
  padding: 10px 0;
  border: 1px solid #222;
  border-radius: 10px;
  background: #111;
  color: #fff;
  font-family: 'DM Sans', sans-serif;
  font-size: clamp(0.85rem, 1.2vh, 1rem);
  font-weight: 700;
  letter-spacing: 0.5px;
  text-align: center;
  text-decoration: none;
  cursor: pointer;
  transition: background 0.2s, box-shadow 0.2s, border-color 0.2s;
  animation: enterBtnFadeIn 0.5s ease both;
}
.scene-enter-btn:hover {
  background: #222;
  border-color: #444;
  box-shadow: 0 0 14px rgba(0,0,0,0.3);
}
@keyframes enterBtnFadeIn {
  from { opacity: 0; transform: translateY(6px); }
  to   { opacity: 1; transform: translateY(0); }
}


/* ── Auth gate screen ──────────────────────────────────────────────── */
.auth-gate-wrap {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  min-height: 60vh;
  text-align: center;
  gap: clamp(16px, 2.5vh, 28px);
}
.auth-gate-icon {
  font-size: clamp(48px, 7vh, 72px);
  line-height: 1;
}
.auth-gate-title {
  font-size: clamp(1.1rem, 2.2vh, 1.5rem);
  font-weight: 700;
}
.auth-gate-sub {
  color: var(--muted);
  font-size: clamp(0.8rem, 1.3vh, 0.95rem);
  max-width: 380px;
  line-height: 1.6;
}
.auth-gate-btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: clamp(12px, 1.8vh, 18px) clamp(32px, 5vw, 56px);
  border-radius: 12px;
  border: none;
  background: linear-gradient(135deg, var(--t4), #6a5acd);
  color: #fff;
  font-family: 'DM Sans', sans-serif;
  font-size: clamp(13px, 1.6vh, 17px);
  font-weight: 700;
  letter-spacing: 1.5px;
  text-transform: uppercase;
  cursor: pointer;
  transition: all 0.2s;
}
.auth-gate-btn:hover { transform: translateY(-1px); box-shadow: 0 6px 24px rgba(77,157,224,0.4); }
.auth-gate-back {
  color: var(--muted);
  font-size: clamp(0.72rem, 1vh, 0.85rem);
  background: none;
  border: none;
  cursor: pointer;
  text-decoration: underline;
  font-family: 'DM Sans', sans-serif;
}
.auth-gate-back:hover { color: var(--text); }

/* Hub rows — each row is its own grid */
.hub-row {
  display: grid;
  gap: clamp(12px, 2vw, 20px);
  margin-bottom: clamp(12px, 2vw, 20px);
}
.hub-row-top {
  grid-template-columns: 1fr;
  align-items: stretch;
  max-width: 336px;
  margin-left: auto;
  margin-right: auto;
  margin-bottom: 0;
}
.hub-progress-row {
  width: 100%;
  display: flex;
  justify-content: center;
  margin-bottom: 0;
}
.hub-progress-row .progress-frame {
  width: 100%;
  max-width: 336px;
  border-radius: 0;
  padding: clamp(6px, 1vh, 10px) clamp(8px, 1.2vw, 14px);
}
.hub-unlock-hint {
  font-family: 'DM Sans', sans-serif;
  font-size: clamp(0.87rem, 1.35vh, 1.02rem);
  color: #000;
  text-align: center;
  margin: 0 0 clamp(10px, 1.5vh, 16px);
}
.hub-row-top > .ls-card {
  padding: 0;
}
.hub-row-top .progress-scene-title {
  font-size: clamp(0.85rem, 1.4vh, 1rem);
  margin-bottom: 0;
}
.hub-row-top .progress-scene-num {
  font-size: clamp(0.7rem, 1vh, 0.8rem);
}
.hub-row-top .progress-cup-row {
  gap: 6px;
  font-size: clamp(0.75rem, 1.1vh, 0.88rem);
}
.hub-row-top .progress-cup-row .cup-icon {
  width: 24px;
  height: 24px;
}
.hub-row-top .progress-cup-row .cup-pct {
  font-size: clamp(0.7rem, 1vh, 0.8rem);
}
.hub-row-skills-3 {
  grid-template-columns: 1fr 1fr 1fr;
  gap: 0;
  margin-bottom: 0;
}
.hub-row-skills-2 {
  grid-template-columns: 1fr 1fr;
  max-width: 66.666%;
  margin-left: auto;
  margin-right: auto;
  gap: 0;
}

/* Summary text below scene title */
.hub-intro-summary {
  text-align: center;
  margin-bottom: clamp(12px, 2vh, 20px);
  line-height: 1.6;
  background: #fdf6ec;
  border: 1px solid #1a1a1a;
  border-radius: 10px;
  padding: 12px 20px;
  display: inline-block;
}
.hub-intro-summary .hub-intro-desc {
  font-family: 'DM Sans', sans-serif;
  color: var(--text);
  font-size: clamp(0.87rem, 1.35vh, 1.02rem);
  margin: 0 0 4px;
}
.hub-intro-summary .hub-intro-counts {
  font-family: 'DM Sans', sans-serif;
  font-weight: 700;
  color: var(--text);
  font-size: clamp(0.87rem, 1.35vh, 1.02rem);
  margin: 0 0 4px;
}

/* Legacy alias */
.skill-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: clamp(12px, 2vw, 20px);
}

.skill-card {
  cursor: pointer;
  transition: all 0.25s;
  display: flex;
  flex-direction: column;
  gap: 8px;
  border-radius: 0;
}
.skill-card:hover {
  border-color: #2d9de0;
  outline: 1px solid #2d9de0;
  box-shadow: none;
  transform: translateY(0);
}

.skill-card-header {
  display: flex;
  align-items: center;
  gap: 8px;
}

.skill-card-icon {
  font-size: clamp(1.375rem, 2.5vh, 1.75rem);
}

.skill-card-title {
  font-size: clamp(1.06rem, 1.625vh, 1.25rem);
  font-weight: 800;
  letter-spacing: 1px;
  text-transform: uppercase;
  color: #fff;
}

.skill-card-desc {
  font-size: clamp(0.9rem, 1.25vh, 1.06rem);
  color: #fff;
  line-height: 1.5;
}

.skill-card-progress {
  font-size: clamp(0.85rem, 1.125vh, 1rem);
  color: #fff;
  margin-top: auto;
  display: flex;
  align-items: center;
  gap: 6px;
}

.skill-card-progress .cup-icon {
  width: 18px;
  height: 18px;
  flex-shrink: 0;
}


/* ══════════════════════════════════════════════════════════════════════
   PHASE SYSTEM — Watch, Tone Instruction, Vocabulary Teaching
   ══════════════════════════════════════════════════════════════════════ */

/* ── Phase Bar ────────────────────────────────────────────────────── */

.phase-bar {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 0;
  margin-bottom: clamp(16px, 2.5vh, 28px);
  padding: 0 8px;
  flex-wrap: nowrap;
}

.phase-step {
  display: flex;
  align-items: center;
  gap: 6px;
  padding: 6px 12px;
  border-radius: 20px;
  font-size: clamp(0.7rem, 1.1vh, 0.85rem);
  font-weight: 600;
  cursor: pointer;
  transition: all 0.2s;
  white-space: nowrap;
  border: 1px solid transparent;
}
.phase-num {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 22px;
  height: 22px;
  border-radius: 50%;
  font-size: 0.7rem;
  font-weight: 800;
}
.phase-label {
  display: inline;
}

.phase-step.current {
  background: rgba(77,157,224,0.15);
  border-color: var(--t4);
  color: var(--t4);
}
.phase-step.current .phase-num {
  background: var(--t4);
  color: #fff;
}

.phase-step.completed {
  color: var(--correct);
  cursor: pointer;
}
.phase-step.completed .phase-num {
  background: var(--correct);
  color: #fff;
}
.phase-step.completed .phase-num::after {
  content: '\2713';
  font-size: 0.6rem;
}
.phase-step.completed .phase-num {
  font-size: 0;
}

.phase-step.unlocked {
  color: var(--muted);
  cursor: pointer;
}
.phase-step.unlocked .phase-num {
  background: var(--surface2);
  color: var(--muted);
}

.phase-step.locked {
  color: rgba(107,107,133,0.4);
  cursor: default;
  pointer-events: none;
}
.phase-step.locked .phase-num {
  background: rgba(42,42,58,0.5);
  color: rgba(107,107,133,0.4);
}

.phase-connector {
  width: 16px;
  height: 2px;
  background: var(--border);
  flex-shrink: 0;
}

/* ── Tone color utility classes ──────────────────────────────────── */

.tc1 { color: var(--t1); }
.tc2 { color: var(--t2); }
.tc3 { color: var(--t3); }
.tc4 { color: var(--t4); }
.tcn { color: var(--tn); }


/* ── Phase Continue Button ───────────────────────────────────────── */

.phase-continue {
  margin-top: clamp(12px, 2vh, 20px);
  animation: enterBtnFadeIn 0.4s ease both;
}


/* ── PHASE 1: WATCH MODE ─────────────────────────────────────────── */

#screen-phase-watch {
  padding-top: clamp(12px, 2vh, 20px);
  width: 100%;
  max-width: 720px;
}

.watch-theatre {
  position: relative;
  width: 100%;
  border-radius: 14px;
  overflow: hidden;
  background: #000;
  border: 1px solid var(--border);
}

.watch-bg-wrap {
  position: relative;
  width: 100%;
  aspect-ratio: 16 / 9;
  background: #111;
  border-radius: inherit;
  overflow: hidden;
}
.watch-bg-img {
  width: 100%;
  height: 100%;
  object-fit: contain;
  display: block;
}
.watch-bg-overlay {
  position: absolute;
  inset: 0;
  background: none;
  pointer-events: none;
}

.watch-subtitle-area {
  position: absolute;
  bottom: 8px;
  left: 50%;
  transform: translateX(-50%);
  width: auto;
  min-width: 240px;
  max-width: 90%;
  text-align: center;
  padding: 14px 24px 12px;
  pointer-events: none;
  background: rgba(0, 0, 0, 0.75);
  backdrop-filter: blur(6px);
  -webkit-backdrop-filter: blur(6px);
  border-radius: 14px;
  border: 1px solid rgba(255, 255, 255, 0.1);
  transition: opacity 0.25s ease;
  color: #ffffff !important;
}
.watch-speaker {
  font-size: clamp(0.65rem, 1vh, 0.8rem);
  color: rgba(255,255,255,0.7) !important;
  text-transform: uppercase;
  letter-spacing: 1.5px;
  margin-bottom: 6px;
}
.watch-speaker:empty { display: none; }
.watch-speaker.watch-speaker-user {
  color: var(--t2) !important;
}
.watch-pinyin {
  font-size: clamp(1.4rem, 3vh, 2rem);
  font-weight: 700;
  line-height: 1.3;
  margin-bottom: 4px;
  color: #ffffff !important;
}
.watch-pinyin span { color: #ffffff !important; }
.watch-pinyin span {
  color: #ffffff !important;
}
.watch-zh {
  font-family: 'Noto Serif SC', serif;
  font-size: clamp(1rem, 2vh, 1.3rem);
  color: rgba(255,255,255,0.85) !important;
  margin-bottom: 6px;
}
.watch-en {
  font-size: clamp(1.1rem, 2.2vh, 1.5rem);
  font-weight: 600;
  color: #ffffff !important;
}
.watch-loading {
  text-align: center;
  color: var(--muted);
  padding: 20px;
  font-size: 0.9rem;
}

.watch-controls {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 10px 14px;
  margin-top: 10px;
  background: var(--card-bg, rgba(0,0,0,0.4));
  border-radius: 10px;
  border: 1px solid var(--border);
}
.watch-ctrl-btn {
  background: none;
  border: 1px solid rgba(255,255,255,0.2);
  border-radius: 50%;
  width: 36px;
  height: 36px;
  color: #fff;
  font-size: 14px;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: all 0.2s;
  flex-shrink: 0;
}
.watch-ctrl-btn:hover {
  border-color: var(--t4);
  background: rgba(77,157,224,0.15);
}
.watch-progress-wrap {
  flex: 1;
  display: flex;
  flex-direction: column;
  gap: 3px;
}
.watch-progress-track {
  width: 100%;
  height: 4px;
  border-radius: 2px;
  background: rgba(255,255,255,0.15);
  overflow: hidden;
}
.watch-progress-fill {
  height: 100%;
  border-radius: 2px;
  background: linear-gradient(90deg, var(--t4), #6a5acd);
  width: 0%;
  transition: width 0.3s ease;
}
.watch-progress-label {
  font-size: clamp(0.55rem, 0.8vh, 0.65rem);
  color: rgba(255,255,255,0.5);
  text-align: center;
}


/* ── PHASE 2: TONE INSTRUCTION ───────────────────────────────────── */

#screen-phase-tones {
  padding-top: clamp(12px, 2vh, 20px);
  width: 100%;
  max-width: 520px;
}

.tone-teach-wrap {
  width: 100%;
}

.tone-teach-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 16px;
  padding: clamp(20px, 3vh, 32px);
  text-align: center;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: clamp(10px, 1.5vh, 16px);
}

.tone-teach-badge {
  display: inline-block;
  padding: 4px 16px;
  border-radius: 20px;
  font-size: clamp(0.85rem, 1.3vh, 1rem);
  font-weight: 800;
  color: #fff;
  letter-spacing: 1px;
  text-transform: uppercase;
}

.tone-teach-label {
  font-size: clamp(1.1rem, 2vh, 1.4rem);
  font-weight: 700;
  color: var(--text);
}

.tone-teach-canvas {
  width: 100%;
  max-width: 280px;
  height: 100px;
  border-radius: 8px;
  background: rgba(0,0,0,0.3);
}

.tone-teach-desc {
  font-size: clamp(0.85rem, 1.3vh, 1rem);
  color: rgba(255,255,255,0.8);
  line-height: 1.6;
  max-width: 380px;
}

.tone-teach-analogy {
  font-size: clamp(0.8rem, 1.1vh, 0.9rem);
  color: var(--muted);
  font-style: italic;
}

.tone-teach-example {
  background: var(--surface2);
  border-radius: 12px;
  padding: clamp(12px, 2vh, 20px);
  width: 100%;
  max-width: 300px;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 4px;
}

.tone-teach-example-py {
  font-size: clamp(1.6rem, 3vh, 2.2rem);
  font-weight: 700;
}

.tone-teach-example-zh {
  font-family: 'Noto Serif SC', serif;
  font-size: clamp(1.1rem, 2vh, 1.5rem);
  color: rgba(255,255,255,0.8);
}

.tone-teach-example-en {
  font-size: clamp(0.8rem, 1.2vh, 0.95rem);
  color: var(--muted);
}

.tone-teach-play {
  margin-top: 6px;
  padding: 8px 20px;
  border-radius: 20px;
  border: 1px solid var(--border);
  background: var(--surface);
  color: var(--text);
  font-family: 'DM Sans', sans-serif;
  font-size: clamp(0.8rem, 1.1vh, 0.9rem);
  font-weight: 600;
  cursor: pointer;
  transition: all 0.2s;
}
.tone-teach-play:hover {
  border-color: var(--t4);
  background: rgba(77,157,224,0.1);
}

.tone-teach-nav, .vocab-teach-nav {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 16px;
  margin-top: clamp(12px, 2vh, 20px);
}

.phase-nav-arrow {
  width: 40px;
  height: 40px;
  border-radius: 50%;
  border: 1px solid var(--border);
  background: var(--surface);
  color: var(--text);
  font-size: 1.1rem;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: all 0.2s;
}
.phase-nav-arrow:hover {
  border-color: var(--t4);
  background: rgba(77,157,224,0.1);
}

.phase-card-counter {
  font-size: clamp(0.8rem, 1.2vh, 0.95rem);
  color: var(--muted);
  min-width: 100px;
  text-align: center;
}


/* ── PHASE 3: VOCABULARY & SENTENCES ─────────────────────────────── */

#screen-phase-vocab {
  padding-top: clamp(12px, 2vh, 20px);
  width: 100%;
  max-width: 520px;
}

.vocab-card-inner {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 16px;
  padding: clamp(24px, 3.5vh, 40px) clamp(20px, 3vh, 32px);
  text-align: center;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: clamp(8px, 1.2vh, 14px);
  min-height: 240px;
}

.vocab-card-type-badge {
  display: inline-block;
  padding: 3px 12px;
  border-radius: 12px;
  font-size: clamp(0.65rem, 0.9vh, 0.75rem);
  font-weight: 700;
  letter-spacing: 1.5px;
  text-transform: uppercase;
  background: rgba(77,157,224,0.15);
  color: var(--t4);
}
.vocab-card-type-badge.sentence-badge {
  background: rgba(199,125,255,0.15);
  color: var(--tn);
}

.vocab-card-speaker {
  font-size: clamp(0.7rem, 1vh, 0.8rem);
  color: var(--muted);
  text-transform: uppercase;
  letter-spacing: 1px;
}

.vocab-card-pinyin {
  font-size: clamp(2rem, 4vh, 3rem);
  font-weight: 700;
  line-height: 1.2;
}

.vocab-card-zh {
  font-family: 'Noto Serif SC', serif;
  font-size: clamp(1.2rem, 2.2vh, 1.6rem);
  color: rgba(255,255,255,0.8);
}

.vocab-card-en {
  font-size: clamp(0.9rem, 1.4vh, 1.1rem);
  color: var(--muted);
  max-width: 320px;
  line-height: 1.5;
}


/* ── Responsive: mobile ─────────────────────────────────────────────── */

@media (max-width: 640px) {
  .hub-top { grid-template-columns: 1fr; }
  .skill-grid { grid-template-columns: 1fr; }
  .hub-row-top { grid-template-columns: 1fr; }
  .hub-row-skills-3 { grid-template-columns: 1fr 1fr; }
  .hub-row-skills-2 { grid-template-columns: 1fr; max-width: 100%; }
  .phase-label { display: none; }
  .phase-step { padding: 6px 8px; }
  .phase-connector { width: 8px; }
}