/* B 模块 · 声音的大小：语音球（大/小视觉差异 + 播放振幅动效） */
.mb-size-learn-wrap {
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.mb-size-pair-head {
  margin: 0;
  font-size: 1rem;
  font-weight: 600;
  color: var(--text);
  text-align: center;
}

.mb-size-pair-row {
  display: flex;
  align-items: flex-end;
  justify-content: center;
  gap: clamp(28px, 10vw, 72px);
  flex-wrap: wrap;
}

.mb-voice-orb-btn {
  position: relative;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 8px;
  padding: 8px;
  border: none;
  background: transparent;
  cursor: pointer;
}

.mb-voice-orb-btn:disabled {
  opacity: 0.45;
  cursor: not-allowed;
}

.mb-voice-orb-shell {
  position: relative;
  display: flex;
  align-items: center;
  justify-content: center;
  width: 96px;
  height: 96px;
}

/* 学习 / 测试：球体统一尺寸，大/小差异靠波形振幅与配色 */
.mb-voice-orb-btn--neutral .mb-voice-orb-core,
.mb-voice-orb-btn--quiet .mb-voice-orb-core,
.mb-voice-orb-btn--loud .mb-voice-orb-core,
.mb-voice-orb-btn--uniform .mb-voice-orb-core {
  width: 56px;
  height: 56px;
}

.mb-voice-orb-btn--neutral .mb-voice-orb-core {
  background: radial-gradient(circle at 35% 30%, #b8d4f2 0%, var(--primary) 58%, #4a7aad 100%);
  box-shadow: 0 4px 12px rgba(45, 90, 140, 0.28);
}

.mb-voice-orb-btn--quiet .mb-voice-orb-core {
  background: radial-gradient(circle at 40% 35%, #e8f2fc 0%, #8eb8e0 52%, #6a94be 100%);
  box-shadow: 0 3px 10px rgba(80, 120, 160, 0.24);
}

.mb-voice-orb-btn--quiet .mb-voice-orb-ring {
  border-color: rgba(120, 160, 200, 0.4);
  border-width: 1.5px;
}

.mb-voice-orb-btn--quiet .mb-voice-orb-label {
  color: var(--sub-text);
  font-size: 0.88rem;
}

.mb-voice-orb-btn--loud .mb-voice-orb-core {
  background: radial-gradient(circle at 32% 28%, #c5e0ff 0%, #3d7ab8 45%, #1f4f82 100%);
  box-shadow:
    0 5px 18px rgba(25, 70, 130, 0.4),
    0 0 20px rgba(60, 130, 210, 0.28);
}

.mb-voice-orb-btn--loud .mb-voice-orb-ring {
  border-color: rgba(40, 100, 180, 0.5);
  border-width: 2.5px;
}

.mb-voice-orb-btn--loud .mb-voice-orb-label {
  font-size: 0.92rem;
  color: var(--primary);
}

.mb-voice-orb-btn--uniform .mb-voice-orb-core {
  background: radial-gradient(circle at 36% 32%, #c8dcf4 0%, var(--primary) 55%, #4a7aad 100%);
  box-shadow: 0 4px 12px rgba(45, 90, 140, 0.26);
}

.mb-voice-orb-btn--uniform .mb-voice-orb-label {
  font-weight: 600;
  color: var(--text);
}

.mb-voice-orb-core {
  border-radius: 50%;
  position: relative;
  z-index: 2;
  transition: transform 0.08s ease-out;
  will-change: transform;
}

.mb-voice-orb-btn:hover:not(:disabled) .mb-voice-orb-core {
  filter: brightness(1.05);
}

.mb-voice-orb-ring {
  position: absolute;
  inset: 0;
  border-radius: 50%;
  border: 2px solid rgba(99, 143, 189, 0.45);
  opacity: 0;
  transform: scale(0.88);
  pointer-events: none;
}

.mb-voice-orb-ring--3 {
  display: none;
}

.mb-voice-orb-btn--loud .mb-voice-orb-ring--3 {
  display: block;
}

.mb-voice-orb-btn.is-playing .mb-voice-orb-ring {
  animation: mb-orb-ring-pulse 1.1s ease-out infinite;
}

.mb-voice-orb-btn--quiet.is-playing .mb-voice-orb-ring {
  animation-name: mb-orb-ring-pulse-quiet;
}

.mb-voice-orb-btn--loud.is-playing .mb-voice-orb-ring {
  animation-name: mb-orb-ring-pulse-loud;
}

.mb-voice-orb-btn.is-playing .mb-voice-orb-ring--2 {
  animation-delay: 0.28s;
}

.mb-voice-orb-btn--loud.is-playing .mb-voice-orb-ring--3 {
  animation-delay: 0.55s;
}

.mb-voice-orb-bars {
  position: absolute;
  left: 50%;
  top: 50%;
  transform: translate(-50%, -50%);
  display: flex;
  align-items: flex-end;
  justify-content: center;
  gap: 3px;
  width: 28px;
  height: 20px;
  opacity: 0.45;
  z-index: 3;
  pointer-events: none;
}

.mb-voice-orb-bars span {
  display: block;
  width: 3px;
  height: 4px;
  border-radius: 2px;
  background: #fff;
}

.mb-voice-orb-btn.is-playing .mb-voice-orb-bars {
  opacity: 0.95;
}

.mb-voice-orb-label {
  font-weight: 600;
  color: var(--text);
}

.mb-voice-orb-hint {
  font-size: 0.78rem;
  color: var(--sub-text);
  min-height: 1.2em;
}

@keyframes mb-orb-ring-pulse {
  0% {
    opacity: 0.7;
    transform: scale(0.92);
  }
  100% {
    opacity: 0;
    transform: scale(1.3);
  }
}

@keyframes mb-orb-ring-pulse-quiet {
  0% {
    opacity: 0.55;
    transform: scale(0.94);
  }
  100% {
    opacity: 0;
    transform: scale(1.12);
  }
}

@keyframes mb-orb-ring-pulse-loud {
  0% {
    opacity: 0.85;
    transform: scale(0.9);
  }
  100% {
    opacity: 0;
    transform: scale(1.55);
  }
}

/* 测试：双音频选项卡（方框内含语音球，悬停/选中高亮） */
.mb-size-test-panel {
  display: flex;
  flex-direction: column;
  gap: 16px;
  margin-top: 8px;
}

.mb-size-test-intro {
  margin: 0;
  font-size: 0.92rem;
  color: var(--sub-text);
  text-align: center;
}

.mb-size-test-prompt {
  margin: 0;
  font-size: 1.05rem;
  font-weight: 700;
  text-align: center;
  color: var(--text);
}

.mb-size-test-cols {
  display: flex;
  flex-wrap: wrap;
  gap: 20px;
  justify-content: center;
  align-items: stretch;
}

.mb-size-test-option {
  position: relative;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 6px;
  padding: 14px 18px 12px;
  min-width: 128px;
  border: 2px solid var(--border-light);
  border-radius: 16px;
  background: var(--panel);
  box-shadow: var(--shadow-sm);
  transition:
    transform 0.22s cubic-bezier(0.34, 1.45, 0.64, 1),
    border-color 0.2s ease,
    background 0.2s ease,
    box-shadow 0.22s ease;
  -webkit-tap-highlight-color: transparent;
}

.mb-size-test-select-surface {
  position: absolute;
  inset: 0;
  z-index: 1;
  margin: 0;
  padding: 0;
  border: none;
  border-radius: inherit;
  background: transparent;
  cursor: pointer;
}

.mb-size-test-orb-stack {
  position: relative;
  z-index: 2;
  display: flex;
  flex-direction: column;
  align-items: center;
  pointer-events: none;
}

.mb-size-test-option:hover {
  transform: scale(1.05);
  border-color: rgba(var(--primary-rgb), 0.55);
  background: var(--primary-soft);
  box-shadow: var(--shadow-md);
}

.mb-size-test-option.is-selected {
  transform: scale(1.03);
  border-color: var(--primary);
  background: rgba(var(--primary-rgb), 0.14);
  box-shadow:
    0 0 0 4px var(--primary-soft),
    var(--shadow-md);
}

.mb-size-test-option.is-selected:hover {
  transform: scale(1.06);
  background: rgba(var(--primary-rgb), 0.2);
}

.mb-size-test-select-surface:focus {
  outline: none;
}

.mb-size-test-option:has(.mb-size-test-select-surface:focus-visible) {
  border-color: var(--primary);
  box-shadow:
    0 0 0 3px var(--panel),
    0 0 0 5px var(--primary);
}

.mb-size-test-option.is-selected:has(.mb-size-test-select-surface:focus-visible) {
  box-shadow:
    0 0 0 3px var(--panel),
    0 0 0 5px var(--primary),
    0 0 0 8px var(--primary-soft);
}

.mb-size-test-option .mb-voice-orb-btn {
  margin: 0;
  pointer-events: none;
}

.mb-size-test-option .mb-voice-orb-shell {
  pointer-events: auto;
  cursor: pointer;
}

.mb-size-test-option .mb-voice-orb-label,
.mb-size-test-option .mb-voice-orb-hint {
  pointer-events: none;
}

.mb-size-test-option .mb-voice-orb-shell:focus {
  outline: none;
}

.mb-size-test-option .mb-voice-orb-shell:focus-visible {
  outline: 2px solid var(--primary);
  outline-offset: 3px;
  border-radius: 50%;
}

.mb-size-test-option .btn {
  pointer-events: auto;
  cursor: pointer;
}

.mb-size-test-option .mb-voice-orb-label {
  transition: color 0.2s ease;
}

.mb-size-test-option:hover .mb-voice-orb-label,
.mb-size-test-option.is-selected .mb-voice-orb-label {
  color: var(--primary);
}

.mb-size-test-panel.pretest-hidden {
  display: none !important;
}

/* 本轮测试总结弹窗 */
.pretest-modal-custom-body {
  margin: 0;
  max-height: min(52vh, 420px);
  overflow-y: auto;
}

.mb-size-round-summary {
  display: flex;
  flex-direction: column;
  gap: 14px;
}

.mb-size-round-summary-lead {
  margin: 0;
  font-size: 0.95rem;
  color: var(--sub-text);
  text-align: center;
}

.mb-size-summary-item {
  border: 1px solid var(--border-light);
  border-radius: 12px;
  padding: 12px;
  background: var(--ops-bg);
}

.mb-size-summary-item-head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 10px;
  margin-bottom: 6px;
  font-weight: 700;
  font-size: 0.95rem;
}

.mb-size-summary-badge {
  flex-shrink: 0;
  padding: 2px 10px;
  border-radius: 999px;
  font-size: 0.82rem;
  font-weight: 600;
}

.mb-size-summary-badge.is-correct {
  color: #0f766e;
  background: rgba(15, 118, 110, 0.12);
}

.mb-size-summary-badge.is-wrong {
  color: #b45309;
  background: rgba(180, 83, 9, 0.12);
}

.mb-size-summary-prompt {
  margin: 0 0 10px;
  font-size: 0.88rem;
  color: var(--sub-text);
}

.mb-size-summary-orbs {
  display: flex;
  flex-wrap: wrap;
  gap: 16px;
  justify-content: center;
}

/* 训练小节：今日测试完成后右上角打勾 */
.distance-btn-wrap {
  position: relative;
}

.distance-btn.done::after {
  content: none;
}

/* B 模块 · 声音的高低：音高柱状图（高/低视觉差异 + 播放频谱动效） */
.mb-pitch-learn-wrap {
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.mb-pitch-pair-head {
  margin: 0;
  font-size: 1rem;
  font-weight: 600;
  color: var(--text);
  text-align: center;
}

.mb-pitch-pair-row {
  display: flex;
  align-items: flex-end;
  justify-content: center;
  gap: clamp(28px, 10vw, 72px);
  flex-wrap: wrap;
}

.mb-pitch-bar-btn {
  position: relative;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 8px;
  padding: 8px;
  border: none;
  background: transparent;
  cursor: pointer;
}

.mb-pitch-bar-btn:disabled {
  opacity: 0.45;
  cursor: not-allowed;
}

.mb-pitch-bar-shell {
  position: relative;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 4px;
  width: 88px;
}

.mb-pitch-bar-track {
  position: relative;
  width: 72px;
  height: 96px;
  border-radius: 12px;
  background: linear-gradient(180deg, rgba(var(--primary-rgb), 0.06) 0%, rgba(var(--primary-rgb), 0.14) 100%);
  border: 2px solid rgba(var(--primary-rgb), 0.22);
  box-shadow: inset 0 2px 8px rgba(30, 60, 100, 0.08);
  overflow: hidden;
}

.mb-pitch-bar-cols {
  position: absolute;
  inset: 8px 6px 6px;
  display: flex;
  align-items: flex-end;
  justify-content: center;
  gap: 3px;
}

.mb-pitch-bar-col {
  flex: 1;
  display: flex;
  align-items: flex-end;
  height: 100%;
  min-width: 0;
}

.mb-pitch-bar-fill {
  display: block;
  width: 100%;
  height: 18%;
  border-radius: 3px 3px 1px 1px;
  background: linear-gradient(180deg, #9ec5ea 0%, var(--primary) 55%, #3d6a9e 100%);
  transition: height 0.06s ease-out;
  will-change: height;
}

.mb-pitch-bar-btn--low .mb-pitch-bar-fill {
  background: linear-gradient(180deg, #b8cfe4 0%, #7aa3cc 50%, #5a84ad 100%);
}

.mb-pitch-bar-btn--high .mb-pitch-bar-fill {
  background: linear-gradient(180deg, #c8e4ff 0%, #4a8fd4 45%, #2d6aa8 100%);
  box-shadow: 0 0 6px rgba(60, 130, 210, 0.35);
}

.mb-pitch-bar-btn--uniform .mb-pitch-bar-fill {
  background: linear-gradient(180deg, #b8d4f2 0%, var(--primary) 58%, #4a7aad 100%);
}

.mb-pitch-bar-arrow {
  font-size: 0.72rem;
  line-height: 1;
  color: var(--primary);
  opacity: 0.75;
  transition: transform 0.1s ease-out;
  will-change: transform;
}

.mb-pitch-bar-btn--low .mb-pitch-bar-arrow {
  color: #6a94be;
}

.mb-pitch-bar-btn--high .mb-pitch-bar-arrow {
  color: #2d6aa8;
  font-size: 0.78rem;
}

.mb-pitch-bar-btn.is-playing .mb-pitch-bar-track {
  border-color: rgba(var(--primary-rgb), 0.45);
  box-shadow:
    inset 0 2px 8px rgba(30, 60, 100, 0.08),
    0 0 12px rgba(var(--primary-rgb), 0.2);
}

.mb-pitch-bar-btn.is-playing .mb-pitch-bar-arrow {
  opacity: 1;
}

.mb-pitch-bar-btn:hover:not(:disabled) .mb-pitch-bar-track {
  border-color: rgba(var(--primary-rgb), 0.4);
}

.mb-pitch-bar-label {
  font-weight: 600;
  color: var(--text);
}

.mb-pitch-bar-btn--low .mb-pitch-bar-label {
  color: var(--sub-text);
  font-size: 0.88rem;
}

.mb-pitch-bar-btn--high .mb-pitch-bar-label {
  color: var(--primary);
}

.mb-pitch-bar-hint {
  font-size: 0.78rem;
  color: var(--sub-text);
  min-height: 1.2em;
}

.mb-pitch-test-intro {
  margin: 0;
  font-size: 0.92rem;
  color: var(--sub-text);
  text-align: center;
}

.mb-pitch-summary-bars {
  display: flex;
  flex-wrap: wrap;
  gap: 16px;
  justify-content: center;
}

.mb-size-test-option .mb-pitch-bar-btn {
  margin: 0;
  pointer-events: none;
}

.mb-size-test-option .mb-pitch-bar-shell {
  pointer-events: auto;
  cursor: pointer;
}

.mb-size-test-option .mb-pitch-bar-label,
.mb-size-test-option .mb-pitch-bar-hint {
  pointer-events: none;
}

.mb-size-test-option .mb-pitch-bar-shell:focus {
  outline: none;
}

.mb-size-test-option .mb-pitch-bar-shell:focus-visible {
  outline: 2px solid var(--primary);
  outline-offset: 3px;
  border-radius: 12px;
}

.mb-size-test-option:hover .mb-pitch-bar-label,
.mb-size-test-option.is-selected .mb-pitch-bar-label {
  color: var(--primary);
}

/* —— 声音的长短：横向时长音柱 —— */
.mb-duration-learn-wrap {
  display: flex;
  flex-direction: column;
  gap: 12px;
  width: 100%;
}

.mb-duration-pair-head {
  margin: 0;
  font-size: 15px;
  font-weight: 600;
  color: var(--text-secondary, #555);
  text-align: center;
}

.mb-duration-pair-row {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  align-items: flex-end;
  gap: 28px 36px;
}

.mb-duration-bar-btn {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 8px;
  padding: 10px 12px;
  border: none;
  background: transparent;
  cursor: pointer;
  min-width: 140px;
}

.mb-duration-bar-btn:disabled {
  opacity: 0.45;
  cursor: not-allowed;
}

.mb-duration-bar-shell {
  display: flex;
  flex-direction: column;
  align-items: stretch;
  width: 100%;
  max-width: 220px;
}

.mb-duration-bar-track {
  width: 100%;
  padding: 14px 10px;
  border-radius: 12px;
  background: linear-gradient(180deg, rgba(240, 245, 252, 0.95), rgba(228, 236, 248, 0.85));
  border: 1px solid rgba(120, 150, 190, 0.22);
  box-shadow: inset 0 1px 3px rgba(255, 255, 255, 0.7);
}

.mb-duration-bar-btn--short .mb-duration-bar-track,
.mb-duration-bar-btn--long .mb-duration-bar-track,
.mb-duration-bar-btn--uniform .mb-duration-bar-track {
  width: 100%;
  min-width: 180px;
}

.mb-duration-bar-row {
  display: block;
  height: 12px;
  border-radius: 6px;
  background: rgba(180, 195, 215, 0.35);
  overflow: hidden;
}

.mb-duration-bar-fill {
  display: block;
  height: 100%;
  width: 0%;
  border-radius: 6px;
  background: linear-gradient(90deg, #6ba3e8, #3d7fd6);
  transition: none;
}

.mb-duration-bar-btn.is-playing .mb-duration-bar-track {
  border-color: rgba(61, 127, 214, 0.45);
  box-shadow:
    inset 0 1px 3px rgba(255, 255, 255, 0.7),
    0 0 0 2px rgba(61, 127, 214, 0.12);
}

.mb-duration-bar-btn:hover:not(:disabled) .mb-duration-bar-track {
  border-color: rgba(61, 127, 214, 0.35);
}

.mb-duration-bar-label {
  font-size: 14px;
  font-weight: 600;
  color: var(--text-secondary, #555);
  text-align: center;
}

.mb-duration-bar-hint {
  font-size: 12px;
  color: var(--text-muted, #888);
}

.mb-duration-test-intro {
  margin: 0 0 8px;
  font-size: 13px;
  color: var(--text-muted, #888);
  text-align: center;
}

.mb-duration-summary-bars {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 16px 24px;
}

.mb-size-test-option .mb-duration-bar-btn {
  pointer-events: none;
  min-width: 0;
}

.mb-size-test-option .mb-duration-bar-shell {
  pointer-events: auto;
  max-width: 180px;
}

.mb-size-test-option .mb-duration-bar-label,
.mb-size-test-option .mb-duration-bar-hint {
  pointer-events: none;
}

.mb-size-test-option .mb-duration-bar-shell:focus {
  outline: none;
}

.mb-size-test-option .mb-duration-bar-shell:focus-visible {
  outline: 2px solid var(--primary);
  outline-offset: 2px;
  border-radius: 8px;
}

.mb-size-test-option:hover .mb-duration-bar-label,
.mb-size-test-option.is-selected .mb-duration-bar-label {
  color: var(--primary);
}

.distance-btn-wrap:has(.distance-btn.done)::after {
  content: "✓";
  position: absolute;
  top: 1px;
  right: 2px;
  z-index: 2;
  width: 16px;
  height: 16px;
  border-radius: 50%;
  background: #3a8f4d;
  color: #fff;
  font-size: 10px;
  font-weight: 700;
  line-height: 16px;
  text-align: center;
  pointer-events: none;
  box-shadow: 0 1px 4px rgba(58, 143, 77, 0.35);
}

/* B 模块 · 声音的音节数量：三圆点可视化 */
.mb-syllable-learn-wrap {
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.mb-syllable-pair-head {
  margin: 0;
  font-size: 1rem;
  font-weight: 600;
  color: var(--text);
  text-align: center;
}

.mb-syllable-pair-row {
  display: flex;
  align-items: flex-end;
  justify-content: center;
  gap: clamp(28px, 10vw, 72px);
  flex-wrap: wrap;
}

.mb-syllable-circle-btn {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 8px;
  padding: 8px;
  border: none;
  background: transparent;
  cursor: pointer;
}

.mb-syllable-circle-shell {
  display: flex;
  align-items: center;
  justify-content: center;
  min-height: 48px;
}

.mb-syllable-circle-row {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
}

.mb-syllable-circle-dot {
  width: 22px;
  height: 22px;
  border-radius: 50%;
  border: 2px solid rgba(90, 130, 180, 0.45);
  background: rgba(200, 215, 235, 0.35);
  transition:
    background 0.2s ease,
    border-color 0.2s ease,
    box-shadow 0.2s ease,
    transform 0.15s ease;
}

.mb-syllable-circle-dot.is-target {
  border-color: rgba(70, 120, 180, 0.55);
}

.mb-syllable-circle-dot.is-lit {
  background: radial-gradient(circle at 35% 30%, #c5e0ff 0%, var(--primary) 55%, #3d6a9e 100%);
  border-color: var(--primary);
  box-shadow: 0 0 10px rgba(60, 120, 200, 0.45);
  transform: scale(1.06);
}

.mb-syllable-circle-btn.is-playing .mb-syllable-circle-dot.is-lit {
  animation: mb-syllable-pulse 0.55s ease-in-out infinite alternate;
}

@keyframes mb-syllable-pulse {
  from {
    box-shadow: 0 0 6px rgba(60, 120, 200, 0.35);
  }
  to {
    box-shadow: 0 0 14px rgba(60, 120, 200, 0.6);
  }
}

.mb-syllable-circle-label {
  font-size: 0.92rem;
  font-weight: 600;
  color: var(--text);
}

.mb-syllable-circle-hint {
  font-size: 0.8rem;
  color: var(--sub-text);
}

.mb-syllable-circle-btn--neutral .mb-syllable-circle-dot {
  border-color: rgba(90, 130, 180, 0.45);
  background: rgba(200, 215, 235, 0.35);
}

.mb-syllable-circle-btn--neutral.is-playing .mb-syllable-circle-dot {
  background: radial-gradient(circle at 35% 30%, #c5e0ff 0%, var(--primary) 55%, #3d6a9e 100%);
  border-color: var(--primary);
  box-shadow: 0 0 8px rgba(60, 120, 200, 0.35);
}

.mb-size-test-option .mb-syllable-circle-btn {
  pointer-events: none;
}

.mb-size-test-option .mb-syllable-circle-shell {
  pointer-events: auto;
  cursor: pointer;
}

/* 四声辨别 · 答案揭示（声调轨迹 + 语音球） */
.mb-ft-reveal-panel {
  display: flex;
  flex-direction: column;
  gap: 14px;
  margin-top: 12px;
}

.mb-ft-reveal-clip {
  border: 1px solid rgba(99, 143, 189, 0.22);
  border-radius: 12px;
  padding: 10px 12px 12px;
  background: rgba(255, 255, 255, 0.55);
}

.mb-ft-reveal-clip-title {
  margin: 0 0 8px;
  font-size: 14px;
  font-weight: 600;
  color: var(--text, #333);
}

.mb-ft-reveal-clip-body {
  display: flex;
  align-items: stretch;
  gap: 12px;
}

.mb-ft-reveal-orb-col {
  flex: 0 0 auto;
  display: flex;
  align-items: center;
}

.mb-ft-reveal-orb-col .mb-voice-orb-btn {
  min-width: 88px;
}

.mb-ft-tone-stage {
  flex: 1 1 auto;
  min-width: 0;
}

.mb-ft-tone-stage-cap {
  margin: 0 0 4px;
  font-size: 12px;
  color: var(--text-muted, #777);
  text-align: center;
}

.mb-ft-tone-track {
  position: relative;
  height: 72px;
  border-radius: 10px;
  background: linear-gradient(180deg, rgba(99, 143, 189, 0.06) 0%, rgba(99, 143, 189, 0.12) 100%);
  overflow: hidden;
}

.mb-ft-track-dots {
  position: absolute;
  inset: 0;
  pointer-events: none;
}

.mb-ft-track-dot {
  position: absolute;
  width: 7px;
  height: 7px;
  margin: -3.5px 0 0 -3.5px;
  border-radius: 50%;
  background: rgba(99, 143, 189, 0.28);
  transform: translate(-50%, -50%);
}

.mb-ft-tone-ball {
  position: absolute;
  left: 12%;
  top: 50%;
  width: 14px;
  height: 14px;
  margin: -7px 0 0 -7px;
  border-radius: 50%;
  background: radial-gradient(circle at 32% 28%, #e8f3ff 0%, var(--primary, #638fbd) 52%, #3d6a9e 100%);
  box-shadow: 0 2px 8px rgba(60, 120, 200, 0.45);
  transform: translate(-50%, -50%);
  opacity: 0.35;
  transition: opacity 0.2s ease;
}

.mb-ft-tone-track.is-playing .mb-ft-tone-ball {
  opacity: 1;
}

/* 一声：水平 */
.mb-ft-track--flat.is-playing .mb-ft-tone-ball {
  animation: mb-ft-ball-flat 1.35s ease-in-out infinite;
}

@keyframes mb-ft-ball-flat {
  0% {
    left: 12%;
    top: 50%;
  }
  100% {
    left: 88%;
    top: 50%;
  }
}

/* 二声：上升 */
.mb-ft-track--rise.is-playing .mb-ft-tone-ball {
  animation: mb-ft-ball-rise 1.35s ease-in-out infinite;
}

@keyframes mb-ft-ball-rise {
  0% {
    left: 14%;
    top: 72%;
  }
  100% {
    left: 86%;
    top: 22%;
  }
}

/* 三声：U 形 */
.mb-ft-track--dip.is-playing .mb-ft-tone-ball {
  animation: mb-ft-ball-dip 1.6s ease-in-out infinite;
}

@keyframes mb-ft-ball-dip {
  0% {
    left: 12%;
    top: 28%;
  }
  25% {
    left: 32%;
    top: 68%;
  }
  50% {
    left: 50%;
    top: 74%;
  }
  75% {
    left: 68%;
    top: 68%;
  }
  100% {
    left: 88%;
    top: 28%;
  }
}

/* 四声：下降 */
.mb-ft-track--fall.is-playing .mb-ft-tone-ball {
  animation: mb-ft-ball-fall 1.35s ease-in-out infinite;
}

@keyframes mb-ft-ball-fall {
  0% {
    left: 14%;
    top: 24%;
  }
  100% {
    left: 86%;
    top: 76%;
  }
}