/* ===========================================================
   二年级下册第五章《五　认识四位数》· 动手互动实验室专属样式
   全部作用域收拢在 .b1lab-wrap.b5lab-wrap 内，无外链、保证 44px 触控热区
   =========================================================== */
.b1lab-wrap.b5lab-wrap {
  --b5-teal: #18B28E;
  --b5-teal-dark: #0F8A6D;
  --b5-teal-light: #E6FBF5;
  --b5-amber: #D97706;
  --b5-amber-dark: #B45309;
  --b5-amber-light: #FEF3C7;
  --b5-indigo: #4F46E5;
  --b5-indigo-light: #E0E7FF;
  --b5-blue: #0284C7;
  --b5-blue-light: #E0F2FE;
  --b5-emerald: #059669;
  --b5-emerald-light: #D1FAE5;
  --b5-wood: #854D0E;
  --b5-wood-light: #FEF9C3;
  --b5-purple: #7C5CFA;
  --b5-purple-light: #EFEAFF;
}

.b1lab-wrap.b5lab-wrap [tabindex]:focus-visible {
  outline: 3px solid #2563EB;
  outline-offset: 2px;
}

/* 通用操作区容器 */
.b1lab-wrap.b5lab-wrap .b5-board {
  background: #FFFFFF;
  border: 2px solid #E2E8F0;
  border-radius: 20px;
  padding: 14px;
  margin-bottom: 14px;
  box-shadow: 0 4px 12px rgba(15, 23, 42, 0.04);
  position: relative;
}

/* 题目与互动指引栏 */
.b1lab-wrap.b5lab-wrap .b5-hint-banner {
  background: #F8FAFC;
  border-left: 4px solid var(--b5-teal);
  border-radius: 12px;
  padding: 10px 14px;
  margin-bottom: 12px;
  font-size: 15px;
  line-height: 1.5;
  color: #334155;
  display: flex;
  align-items: center;
  gap: 8px;
}

.b1lab-wrap.b5lab-wrap.wisdom-mode .b5-hint-banner {
  border-left-color: var(--b5-purple);
  background: #EFEAFF;
}

/* B1: 千进制方块进位动画区 */
.b1lab-wrap.b5lab-wrap .b5-blocks-arena {
  display: flex;
  flex-direction: column;
  gap: 12px;
  align-items: center;
}

.b1lab-wrap.b5lab-wrap .b5-blocks-stage {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 12px;
  width: 100%;
  padding: 10px;
  background: #F1F5F9;
  border-radius: 16px;
  min-height: 140px;
  align-items: center;
}

.b1lab-wrap.b5lab-wrap .b5-block-group {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 4px;
  padding: 8px 10px;
  background: #FFFFFF;
  border-radius: 12px;
  border: 1.5px solid #CBD5E1;
  min-width: 76px;
}

.b1lab-wrap.b5lab-wrap .b5-group-label {
  font-size: 13px;
  font-weight: 800;
  color: #475569;
}

.b1lab-wrap.b5lab-wrap .b5-group-val {
  font-size: 16px;
  font-weight: 900;
  color: var(--b5-teal-dark);
}

.b1lab-wrap.b5lab-wrap .b5-block-action-bar {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  justify-content: center;
  width: 100%;
}

/* B2: 四位立体计数器 */
.b1lab-wrap.b5lab-wrap .b5-counter-box {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 12px;
  width: 100%;
  max-width: 520px;
  margin: 0 auto;
}

.b1lab-wrap.b5lab-wrap .b5-counter-frame {
  background: #FEF3C7;
  border: 3px solid #D97706;
  border-radius: 20px;
  padding: 12px 10px 8px;
  box-shadow: 0 6px 0 #B45309, 0 10px 20px rgba(180, 83, 9, 0.15);
  width: 100%;
}

.b1lab-wrap.b5lab-wrap .b5-counter-rods {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 8px;
  padding: 10px 4px 6px;
  background: #FFFBEB;
  border-radius: 14px;
  border: 1.5px dashed #F59E0B;
}

.b1lab-wrap.b5lab-wrap .b5-counter-rod-col {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 4px;
}

.b1lab-wrap.b5lab-wrap .b5-rod-stem {
  width: 100%;
  height: 130px;
  background: #F8FAFC;
  border-radius: 10px;
  border: 1px solid #E2E8F0;
  display: flex;
  flex-direction: column-reverse;
  align-items: center;
  padding: 4px 2px;
  gap: 3px;
  position: relative;
  overflow: hidden;
}

.b1lab-wrap.b5lab-wrap .b5-bead-donut {
  width: 90%;
  max-width: 44px;
  height: 10px;
  border-radius: 5px;
  box-shadow: inset 0 2px 0 rgba(255,255,255,0.6), 0 2px 4px rgba(0,0,0,0.15);
  transition: transform 0.12s ease;
}

.b1lab-wrap.b5lab-wrap .b5-counter-ctrls {
  display: flex;
  gap: 4px;
  margin-top: 4px;
}

.b1lab-wrap.b5lab-wrap .b5-rod-btn {
  min-width: 32px;
  min-height: 44px;
  padding: 4px 8px;
  border-radius: 8px;
  background: #FFFFFF;
  border: 1.5px solid #CBD5E1;
  font-size: 15px;
  font-weight: 900;
  box-shadow: 0 2px 0 #94A3B8;
  display: inline-flex;
  align-items: center;
  justify-content: center;
}

.b1lab-wrap.b5lab-wrap .b5-rod-btn:hover:not(:disabled) {
  background: #F1F5F9;
  border-color: #64748B;
}

.b1lab-wrap.b5lab-wrap .b5-rod-tag {
  font-size: 14px;
  font-weight: 900;
  padding: 2px 6px;
  border-radius: 6px;
  background: #D97706;
  color: #FFFFFF;
  margin-top: 4px;
}

.b1lab-wrap.b5lab-wrap .b5-rod-digit {
  font-size: 18px;
  font-weight: 900;
  color: #1E293B;
  min-height: 24px;
}

/* B3: 中国传统五档算盘 */
.b1lab-wrap.b5lab-wrap .b5-abacus-box {
  width: 100%;
  max-width: 500px;
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  gap: 10px;
  align-items: center;
}

.b1lab-wrap.b5lab-wrap .b5-abacus-frame {
  background: #78350F;
  border: 4px solid #451A03;
  border-radius: 16px;
  padding: 8px;
  width: 100%;
  box-shadow: 0 8px 0 #2E1065, 0 12px 24px rgba(0,0,0,0.25);
}

.b1lab-wrap.b5lab-wrap .b5-abacus-inner {
  background: #FEF3C7;
  border: 2px solid #92400E;
  border-radius: 10px;
  padding: 6px 4px;
}

.b1lab-wrap.b5lab-wrap .b5-abacus-beam {
  height: 12px;
  background: #451A03;
  width: 100%;
  margin: 4px 0;
  position: relative;
  display: flex;
  align-items: center;
  justify-content: space-around;
}

.b1lab-wrap.b5lab-wrap .b5-beam-dot {
  width: 6px;
  height: 6px;
  background: #FFFFFF;
  border-radius: 50%;
  box-shadow: 0 0 3px rgba(255,255,255,0.8);
}

.b1lab-wrap.b5lab-wrap .b5-abacus-cols {
  display: grid;
  grid-template-columns: repeat(5, 1fr);
  gap: 6px;
}

.b1lab-wrap.b5lab-wrap .b5-abacus-col {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 2px;
}

.b1lab-wrap.b5lab-wrap .b5-abacus-rod-up,
.b1lab-wrap.b5lab-wrap .b5-abacus-rod-down {
  width: 100%;
  position: relative;
  display: flex;
  flex-direction: column;
  align-items: center;
  background: repeating-linear-gradient(
    to bottom,
    transparent,
    transparent 10px,
    rgba(146, 64, 14, 0.08) 10px,
    rgba(146, 64, 14, 0.08) 20px
  );
}

.b1lab-wrap.b5lab-wrap .b5-abacus-rod-up {
  height: 48px;
  justify-content: flex-start;
}

.b1lab-wrap.b5lab-wrap .b5-abacus-rod-down {
  height: 88px;
  justify-content: flex-end;
}

.b1lab-wrap.b5lab-wrap .b5-abacus-bead {
  width: 90%;
  max-width: 44px;
  height: 16px;
  background: radial-gradient(circle at 40% 30%, #F59E0B, #B45309 80%);
  border-radius: 8px;
  border: 1px solid #78350F;
  box-shadow: 0 2px 3px rgba(0,0,0,0.2);
  cursor: pointer;
  touch-action: manipulation;
  transition: transform 0.1s ease, filter 0.1s ease;
  position: relative;
}

.b1lab-wrap.b5lab-wrap .b5-abacus-bead::before {
  content: '';
  position: absolute;
  top: -4px;
  bottom: -4px;
  left: -2px;
  right: -2px;
}

.b1lab-wrap.b5lab-wrap .b5-abacus-rod-up .b5-abacus-bead::before {
  top: -12px;
  bottom: -12px;
  left: -4px;
  right: -4px;
}

.b1lab-wrap.b5lab-wrap .b5-abacus-bead.bead-active {
  filter: brightness(1.15) contrast(1.1);
  box-shadow: 0 0 0 2px #FDE68A, 0 3px 5px rgba(0,0,0,0.3);
}

.b1lab-wrap.b5lab-wrap .b5-abacus-label-row {
  display: grid;
  grid-template-columns: repeat(5, 1fr);
  gap: 6px;
  margin-top: 6px;
  text-align: center;
}

.b1lab-wrap.b5lab-wrap .b5-abacus-col-label {
  font-size: 13.5px;
  font-weight: 900;
  color: #78350F;
}

.b1lab-wrap.b5lab-wrap .b5-abacus-col-val {
  font-size: 16px;
  font-weight: 900;
  color: #1E293B;
}

/* B4: 数位拆拼板与插槽 */
.b1lab-wrap.b5lab-wrap .b5-pv-slots {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 8px;
  margin-bottom: 12px;
}

.b1lab-wrap.b5lab-wrap .b5-pv-slot {
  border: 2px dashed #94A3B8;
  border-radius: 14px;
  background: #F8FAFC;
  min-height: 84px;
  padding: 8px 4px;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 4px;
  cursor: pointer;
  touch-action: manipulation;
  transition: all 0.12s ease;
}

.b1lab-wrap.b5lab-wrap .b5-pv-slot.filled {
  border-style: solid;
  border-color: var(--b5-teal);
  background: #E6FBF5;
}

.b1lab-wrap.b5lab-wrap .b5-pv-slot-title {
  font-size: 13px;
  font-weight: 900;
  color: #64748B;
}

.b1lab-wrap.b5lab-wrap .b5-pv-slot-val {
  font-size: 20px;
  font-weight: 900;
  color: #0F172A;
}

.b1lab-wrap.b5lab-wrap .b5-card-dock {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  justify-content: center;
  padding: 10px;
  background: #F1F5F9;
  border-radius: 14px;
}

.b1lab-wrap.b5lab-wrap .b5-card-chip {
  min-width: 58px;
  min-height: 48px;
  padding: 6px 12px;
  background: #FFFFFF;
  border: 2px solid #CBD5E1;
  border-radius: 12px;
  box-shadow: 0 4px 0 #94A3B8;
  font-size: 17px;
  font-weight: 900;
  color: #1E293B;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  touch-action: none;
  user-select: none;
  transition: all 0.12s ease;
}

.b1lab-wrap.b5lab-wrap .b5-card-chip.dragging-ghost {
  position: fixed;
  z-index: 9999;
  pointer-events: none;
  opacity: 0.92;
  transform: scale(1.08);
  box-shadow: 0 8px 24px rgba(0, 0, 0, 0.3);
}

.b1lab-wrap.b5lab-wrap .b5-card-chip:hover:not(:disabled) {
  transform: translateY(-2px);
  border-color: var(--b5-teal);
}

.b1lab-wrap.b5lab-wrap .b5-card-chip.selected {
  background: #CCFBF1;
  border-color: var(--b5-teal);
  box-shadow: 0 4px 0 var(--b5-teal-dark), 0 0 0 3px rgba(24, 178, 142, 0.25);
  transform: translateY(-2px) scale(1.05);
}

.b1lab-wrap.b5lab-wrap .b5-card-chip.used {
  opacity: 0.35;
  cursor: not-allowed;
  box-shadow: none;
  transform: none;
}

/* B5: 整千整百加减口算（钞票捆与金库） */
.b1lab-wrap.b5lab-wrap .b5-vault-stage {
  display: flex;
  flex-direction: column;
  gap: 12px;
  align-items: center;
}

.b1lab-wrap.b5lab-wrap .b5-cash-display {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 10px;
  width: 100%;
  padding: 12px;
  background: #ECFDF5;
  border: 2px solid #A7F3D0;
  border-radius: 16px;
  min-height: 90px;
  align-items: center;
}

.b1lab-wrap.b5lab-wrap .b5-cash-bundle {
  padding: 8px 12px;
  border-radius: 10px;
  font-size: 15px;
  font-weight: 900;
  display: inline-flex;
  align-items: center;
  gap: 6px;
  box-shadow: 0 3px 0 rgba(0,0,0,0.1);
  transition: all 0.15s ease;
}

.b1lab-wrap.b5lab-wrap .b5-cash-bundle.thousand {
  background: #FEF08A;
  border: 2px solid #CA8A04;
  color: #854D0E;
}

.b1lab-wrap.b5lab-wrap .b5-cash-bundle.hundred {
  background: #BAE6FD;
  border: 2px solid #0284C7;
  color: #0369A1;
}

.b1lab-wrap.b5lab-wrap .b5-cash-bundle.removed {
  opacity: 0.25;
  text-decoration: line-through;
  filter: grayscale(0.8);
  transform: scale(0.92);
}

/* B6: 数线定位与大小比较 */
.b1lab-wrap.b5lab-wrap .b5-line-box {
  display: flex;
  flex-direction: column;
  gap: 12px;
  width: 100%;
}

.b1lab-wrap.b5lab-wrap .b5-line-track {
  width: 100%;
  position: relative;
  padding: 30px 10px 24px;
  background: #F8FAFC;
  border: 2px solid #E2E8F0;
  border-radius: 16px;
  overflow-x: auto;
}

.b1lab-wrap.b5lab-wrap .b5-line-bar {
  height: 8px;
  background: #0284C7;
  border-radius: 4px;
  position: relative;
  margin: 20px 10px;
}

.b1lab-wrap.b5lab-wrap .b5-line-mark {
  position: absolute;
  top: -8px;
  width: 3px;
  height: 24px;
  background: #0284C7;
  transform: translateX(-50%);
}

.b1lab-wrap.b5lab-wrap .b5-line-mark-label {
  position: absolute;
  top: 26px;
  left: 50%;
  transform: translateX(-50%);
  font-size: 13px;
  font-weight: 800;
  color: #475569;
  white-space: nowrap;
}

.b1lab-wrap.b5lab-wrap .b5-line-drop-dot {
  position: absolute;
  top: -16px;
  transform: translateX(-50%);
  min-width: 44px;
  min-height: 44px;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  touch-action: manipulation;
}

.b1lab-wrap.b5lab-wrap .b5-drop-pin {
  width: 16px;
  height: 16px;
  border-radius: 50%;
  background: #FFFFFF;
  border: 3px solid #64748B;
  box-shadow: 0 2px 4px rgba(0,0,0,0.15);
  transition: all 0.12s ease;
}

.b1lab-wrap.b5lab-wrap .b5-line-drop-dot.filled .b5-drop-pin {
  background: #10B981;
  border-color: #047857;
  transform: scale(1.2);
}

.b1lab-wrap.b5lab-wrap .b5-drop-tag {
  position: absolute;
  bottom: 24px;
  background: #1E293B;
  color: #FFFFFF;
  font-size: 12.5px;
  font-weight: 900;
  padding: 3px 6px;
  border-radius: 6px;
  white-space: nowrap;
  pointer-events: none;
}

/* B7: 约等号“≈”与粮仓挑战 */
.b1lab-wrap.b5lab-wrap .b5-near-stage {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.b1lab-wrap.b5lab-wrap .b5-magnet-track {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 14px;
  background: #EFF6FF;
  border: 2px dashed #93C5FD;
  border-radius: 16px;
  gap: 10px;
}

.b1lab-wrap.b5lab-wrap .b5-magnet-pole {
  font-size: 18px;
  font-weight: 900;
  color: #1D4ED8;
  padding: 8px 12px;
  background: #FFFFFF;
  border-radius: 10px;
  border: 2px solid #BFDBFE;
}

.b1lab-wrap.b5lab-wrap .b5-magnet-ball {
  padding: 8px 14px;
  border-radius: 999px;
  background: #F59E0B;
  color: #FFFFFF;
  font-size: 16px;
  font-weight: 900;
  box-shadow: 0 4px 0 #B45309;
  transition: all 0.3s cubic-bezier(0.34, 1.56, 0.64, 1);
}

.b1lab-wrap.b5lab-wrap .b5-barns-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 10px;
}

.b1lab-wrap.b5lab-wrap .b5-barn-card {
  min-height: 56px;
  padding: 10px 12px;
  border-radius: 14px;
  background: #FFFFFF;
  border: 2.5px solid #E2E8F0;
  box-shadow: 0 3px 0 #CBD5E1;
  display: flex;
  align-items: center;
  justify-content: space-between;
  cursor: pointer;
  touch-action: manipulation;
  transition: all 0.12s ease;
}

.b1lab-wrap.b5lab-wrap .b5-barn-card:hover:not(:disabled) {
  border-color: #94A3B8;
  transform: translateY(-2px);
}

.b1lab-wrap.b5lab-wrap .b5-barn-card.selected {
  background: #ECFDF5;
  border-color: #10B981;
  box-shadow: 0 3px 0 #059669, 0 0 0 3px rgba(16, 185, 129, 0.2);
}

.b1lab-wrap.b5lab-wrap .b5-barn-card.wrong-picked {
  background: #FEF2F2;
  border-color: #EF4444;
  box-shadow: 0 3px 0 #B91C1C;
}

/* W1: 树状有序搭配枝干 */
.b1lab-wrap.b5lab-wrap .b5-tree-box {
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.b1lab-wrap.b5lab-wrap .b5-tree-branches {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  justify-content: center;
}

.b1lab-wrap.b5lab-wrap .b5-tree-btn {
  min-width: 50px;
  min-height: 46px;
  padding: 6px 14px;
  border-radius: 12px;
  background: #FFFFFF;
  border: 2px solid #CBD5E1;
  font-size: 16px;
  font-weight: 900;
  color: #1E293B;
  box-shadow: 0 3px 0 #94A3B8;
  cursor: pointer;
  touch-action: manipulation;
}

.b1lab-wrap.b5lab-wrap .b5-tree-btn.active {
  background: #EDE9FE;
  border-color: #7C5CFA;
  box-shadow: 0 3px 0 #5B38DF;
  color: #5B38DF;
}

.b1lab-wrap.b5lab-wrap .b5-leaf-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 8px;
  padding: 10px;
  background: #EFEAFF;
  border-radius: 14px;
  border: 1.5px dashed #DDD6FE;
}

.b1lab-wrap.b5lab-wrap .b5-leaf-chip {
  min-height: 44px;
  padding: 6px 8px;
  border-radius: 10px;
  background: #FFFFFF;
  border: 1.5px solid #E9D5FF;
  font-size: 15px;
  font-weight: 800;
  color: #6B21A8;
  display: flex;
  align-items: center;
  justify-content: center;
  box-shadow: 0 2px 0 #D8B4FE;
  cursor: pointer;
}

.b1lab-wrap.b5lab-wrap .b5-leaf-chip.lit {
  background: #D8B4FE;
  color: #4A044E;
  font-weight: 900;
  box-shadow: inset 0 2px 4px rgba(0,0,0,0.1);
}

/* W2: 墨迹不等式与数字试选 */
.b1lab-wrap.b5lab-wrap .b5-blot-formula {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 14px;
  background: #FFF7ED;
  border: 2px solid #FED7AA;
  border-radius: 16px;
  font-size: 24px;
  font-weight: 900;
  color: #9A3412;
}

.b1lab-wrap.b5lab-wrap .b5-blot-box {
  width: 44px;
  height: 44px;
  border-radius: 10px;
  background: #475569;
  color: #FFFFFF;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  font-size: 22px;
  box-shadow: inset 0 2px 4px rgba(0,0,0,0.3);
}

.b1lab-wrap.b5lab-wrap .b5-digit-pills {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
  justify-content: center;
  margin-top: 10px;
}

.b1lab-wrap.b5lab-wrap .b5-digit-pill {
  min-width: 42px;
  min-height: 44px;
  padding: 6px 10px;
  border-radius: 10px;
  background: #FFFFFF;
  border: 2px solid #E2E8F0;
  font-size: 17px;
  font-weight: 900;
  color: #334155;
  box-shadow: 0 3px 0 #CBD5E1;
  cursor: pointer;
  touch-action: manipulation;
}

.b1lab-wrap.b5lab-wrap .b5-digit-pill.picked {
  background: #FEF3C7;
  border-color: #D97706;
  box-shadow: 0 3px 0 #B45309;
  color: #B45309;
}

/* W4: 1200张纸推算台与高叠书尺 */
.b1lab-wrap.b5lab-wrap .b5-stack-arena {
  display: flex;
  align-items: flex-end;
  justify-content: center;
  gap: 24px;
  padding: 16px;
  background: #F8FAFC;
  border: 2px solid #E2E8F0;
  border-radius: 16px;
  min-height: 180px;
}

.b1lab-wrap.b5lab-wrap .b5-stack-column {
  display: flex;
  flex-direction: column-reverse;
  align-items: center;
  gap: 2px;
  width: 110px;
}

.b1lab-wrap.b5lab-wrap .b5-book-slice {
  width: 100%;
  height: 9px;
  border-radius: 3px;
  background: linear-gradient(90deg, #3B82F6, #60A5FA 50%, #2563EB);
  border: 1px solid #1D4ED8;
  box-shadow: 0 1px 2px rgba(0,0,0,0.1);
  transition: all 0.12s ease;
}

.b1lab-wrap.b5lab-wrap .b5-ruler-col {
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  height: 150px;
  width: 50px;
  border-left: 3px solid #D97706;
  padding-left: 8px;
  position: relative;
}

.b1lab-wrap.b5lab-wrap .b5-ruler-tick {
  font-size: 13px;
  font-weight: 800;
  color: #B45309;
  position: relative;
}

.b1lab-wrap.b5lab-wrap .b5-ruler-tick::before {
  content: "";
  position: absolute;
  left: -11px;
  top: 50%;
  width: 8px;
  height: 2px;
  background: #D97706;
}

/* 通用答题选项网格与操作按钮 */
.b1lab-wrap.b5lab-wrap .b5-options-grid {
  display: flex;
  flex-direction: column;
  gap: 8px;
  margin-top: 14px;
}

.b1lab-wrap.b5lab-wrap .b5-opt-btn {
  min-height: 48px;
  padding: 10px 16px;
  border-radius: 14px;
  background: #FFFFFF;
  border: 2px solid #E2E8F0;
  box-shadow: 0 3px 0 #CBD5E1;
  font-size: 15.5px;
  font-weight: 800;
  color: #1E293B;
  text-align: left;
  display: flex;
  align-items: center;
  gap: 10px;
  cursor: pointer;
  touch-action: manipulation;
  transition: all 0.12s ease;
}

.b1lab-wrap.b5lab-wrap .b5-opt-btn:hover:not(:disabled) {
  border-color: var(--b5-teal);
  background: #E6FBF5;
}

.b1lab-wrap.b5lab-wrap.wisdom-mode .b5-opt-btn:hover:not(:disabled) {
  border-color: var(--b5-purple);
  background: #EFEAFF;
}

.b1lab-wrap.b5lab-wrap .b5-primary-act {
  min-height: 48px;
  padding: 10px 20px;
  border-radius: 14px;
  background: var(--b5-teal);
  color: #FFFFFF;
  font-size: 16px;
  font-weight: 900;
  border: none;
  box-shadow: 0 4px 0 var(--b5-teal-dark);
  cursor: pointer;
  touch-action: manipulation;
  transition: all 0.12s ease;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 6px;
}

.b1lab-wrap.b5lab-wrap .b5-primary-act:hover:not(:disabled) {
  transform: translateY(-2px);
  filter: brightness(1.05);
}

.b1lab-wrap.b5lab-wrap.wisdom-mode .b5-primary-act {
  background: var(--b5-purple);
  box-shadow: 0 4px 0 #5B38DF;
}

/* 响应式适配：确保 375px 窄屏绝不溢出 */
@media (max-width: 600px) {
  .b1lab-wrap.b5lab-wrap {
    padding: 2px 0 14px;
  }
  .b1lab-wrap.b5lab-wrap .b5-board {
    padding: 10px 8px;
  }
  .b1lab-wrap.b5lab-wrap .b5-pv-slots {
    gap: 4px;
  }
  .b1lab-wrap.b5lab-wrap .b5-counter-rods {
    gap: 4px;
    padding: 6px 2px;
  }
  .b1lab-wrap.b5lab-wrap .b5-rod-btn {
    min-width: 28px;
    min-height: 44px;
    padding: 2px 4px;
  }
  .b1lab-wrap.b5lab-wrap .b5-abacus-cols {
    gap: 3px;
  }
  .b1lab-wrap.b5lab-wrap .b5-barns-grid {
    grid-template-columns: 1fr;
  }
  .b1lab-wrap.b5lab-wrap .b5-leaf-grid {
    grid-template-columns: repeat(2, 1fr);
  }
  .b1lab-wrap.b5lab-wrap .b5-opt-btn {
    font-size: 14.5px;
    padding: 8px 12px;
  }
}

@media (prefers-reduced-motion: reduce) {
  .b1lab-wrap.b5lab-wrap *,
  .b1lab-wrap.b5lab-wrap *::before,
  .b1lab-wrap.b5lab-wrap *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }
}