.tool-modal-header {
  padding-bottom: 16px;
  margin-bottom: 20px;
}

.tool-modal-title {
  font-size: 1.6rem;
  font-weight: 700;
  color: #1e293b;
  margin: 0;
  letter-spacing: -0.03em;
}

.tool-modal-tags {
  display: flex;
  gap: 8px;
}

.tool-modal-tags .grade-tag,
.tool-modal-tags .feature-tag {
  font-size: 0.7rem;
  padding: 3px 8px;
  border-radius: 12px;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.04em;
}

.tool-modal-tags .grade-tag {
  background: #f1f5f9;
  color: #64748b;
}

.tool-modal-tags .feature-tag {
  background: #ecfdf5;
  color: #059669;
}

/* Icon Colors */
.tool-modal-icon.balancer-icon {
  background: linear-gradient(135deg, #fef3c7, #fcd34d);
}

.tool-modal-icon.balancer-icon svg {
  color: #92400e;
}

.tool-modal-icon.molar-icon {
  background: linear-gradient(135deg, #dbeafe, #93c5fd);
}

.tool-modal-icon.molar-icon svg {
  color: #1e40af;
}

.tool-modal-icon.empirical-icon {
  background: linear-gradient(135deg, #f3e8ff, #c4b5fd);
}

.tool-modal-icon.empirical-icon svg {
  color: #6b21a8;
}

.tool-modal-icon.blank-icon {
  background: linear-gradient(135deg, #f1f5f9, #cbd5e1);
}

.tool-modal-icon.blank-icon svg {
  color: #475569;
}

/* Unified Input Style */
.tool-input,
.tool-select,
.balancer-formula-input,
.realtime-input {
  width: 100%;
  padding: 14px 16px;
  border: 1.5px solid #e2e8f0;
  border-radius: 12px;
  font-size: 1.05rem;
  font-weight: 500;
  font-family: "SF Mono", "Monaco", "Consolas", monospace;
  background: #ffffff;
  color: #1e293b;
  transition: all 0.2s ease;
  box-sizing: border-box;
}

.tool-input:focus,
.tool-select:focus,
.balancer-formula-input:focus,
.realtime-input:focus {
  outline: none;
  border-color: #6366f1;
  box-shadow: 0 0 0 3px rgba(99, 102, 241, 0.1);
}

.tool-input::placeholder,
.realtime-input::placeholder {
  color: #94a3b8;
}

/* Unified Button Style */
.tool-button,
.tool-button.primary-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 12px 20px;
  background: linear-gradient(135deg, #1e293b 0%, #334155 100%);
  color: #ffffff;
  border: none;
  border-radius: 12px;
  font-size: 0.95rem;
  font-weight: 600;
  font-family:
    "Inter",
    -apple-system,
    sans-serif;
  cursor: pointer;
  transition: all 0.2s ease;
  box-shadow: 0 2px 4px rgba(0, 0, 0, 0.08);
}

.tool-button:hover,
.tool-button.primary-btn:hover {
  transform: translateY(-1px);
  box-shadow: 0 6px 16px rgba(0, 0, 0, 0.12);
}

.tool-button:active,
.tool-button.primary-btn:active {
  transform: translateY(0);
}

.tool-button svg {
  width: 18px;
  height: 18px;
}

/* Unified Section Labels */
.tool-input-section label,
.tool-input-group label {
  display: block;
  font-size: 0.8rem;
  font-weight: 600;
  color: #64748b;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  margin-bottom: 8px;
}

/* Unified Result Box */
.tool-result-box {
  background: #ffffff;
  border: 1.5px solid #e2e8f0;
  border-radius: 12px;
  padding: 20px;
  margin-top: 16px;
}

.result-label {
  font-size: 0.75rem;
  font-weight: 600;
  color: #64748b;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  margin-bottom: 8px;
}

.result-value {
  font-size: 1.6rem;
  font-weight: 700;
  color: #1e293b;
}

/* Unified Explanation Box */
.tool-explanation-box,
.tool-breakdown-box {
  background: #f8fafc;
  border: 1px solid #e2e8f0;
  border-radius: 12px;
  padding: 16px;
  margin-top: 12px;
  font-size: 0.9rem;
  color: #475569;
  line-height: 1.6;
}

/* Toggle Switch Enhancement */
.toggle-group {
  display: flex;
  flex-direction: column;
  gap: 10px;
  margin-top: 12px;
}

.toggle-label {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 0.85rem;
  font-weight: 500;
  color: #475569;
  cursor: pointer;
  padding: 8px 12px;
  border-radius: 12px;
  transition: background 0.15s ease;
}

.toggle-label:hover {
  background: #f1f5f9;
}

.toggle-label input[type="checkbox"] {
  -webkit-appearance: none;
  appearance: none;
  width: 18px;
  height: 18px;
  border: 1.5px solid #cbd5e1;
  border-radius: 5px;
  cursor: pointer;
  background-color: #fff;
  position: relative;
  transition: all 0.2s ease;
}

.toggle-label input[type="checkbox"]:checked {
  background-color: #6366f1;
  border-color: #6366f1;
}

.toggle-label input[type="checkbox"]:checked::after {
  content: "";
  position: absolute;
  top: 45%;
  left: 50%;
  width: 5px;
  height: 9px;
  border: solid white;
  border-width: 0 2px 2px 0;
  transform: translate(-50%, -60%) rotate(45deg);
}

/* Tips Section */
.tool-tips-section {
  background: #f8fafc;
  border-radius: 12px;
  padding: 16px;
  margin-top: 16px;
}

.tool-tips-section h4 {
  font-size: 0.8rem;
  font-weight: 700;
  color: #64748b;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  margin: 0 0 10px 0;
}

.tool-tips-section p {
  font-size: 0.85rem;
  color: #64748b;
  margin: 6px 0;
  line-height: 1.5;
}

/* Example Chips */
.example-box {
  margin-top: 12px;
}

.example-box strong {
  font-size: 0.8rem;
  color: #64748b;
  font-weight: 600;
}

.formula-chip {
  display: inline-block;
  padding: 6px 12px;
  background: #ffffff;
  border: 1px solid #e2e8f0;
  border-radius: 12px;
  font-size: 0.85rem;
  font-weight: 600;
  color: #475569;
  cursor: pointer;
  transition: all 0.15s ease;
  font-family: "SF Mono", "Monaco", monospace;
}

.formula-chip:hover {
  background: #6366f1;
  border-color: #6366f1;
  color: #ffffff;
  transform: translateY(-1px);
}

/* Balancer Specific Refinements */
.balancer-inputs {
  display: flex;
  align-items: center;
  gap: 12px;
  margin-bottom: 16px;
}

.balancer-input-group {
  flex: 1;
}

.balancer-input-label {
  font-size: 0.75rem;
  font-weight: 600;
  color: #64748b;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  margin-bottom: 6px;
  display: block;
}

.balancer-arrow {
  font-size: 1.2rem;
  color: #94a3b8;
  font-weight: 500;
  margin-top: 20px;
}

.balancer-feedback {
  padding: 10px 14px;
  border-radius: 12px;
  font-size: 0.85rem;
  font-weight: 500;
  margin-bottom: 12px;
}

.balancer-feedback.balanced {
  background: #ecfdf5;
  border: 1px solid #a7f3d0;
  color: #065f46;
}

.balancer-feedback.unbalanced {
  background: #fef3c7;
  border: 1px solid #fcd34d;
  color: #92400e;
}

/* Empirical/Lego Tool Layout Refinements */
.lego-tool-layout {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 20px;
  align-items: start;
}

.lego-input-panel {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.lego-stage {
  background: linear-gradient(135deg, #f8fafc 0%, #f1f5f9 100%);
  border: 1.5px solid #e2e8f0;
  border-radius: 12px;
  min-height: 200px;
  padding: 16px;
  display: flex;
  flex-direction: column;
  justify-content: center;
}

.lego-blocks-container {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  justify-content: center;
  align-items: center;
}

.lego-empty-state {
  text-align: center;
  padding: 24px;
}

.lego-empty-state p {
  color: #94a3b8;
  font-size: 0.85rem;
  margin: 0;
}

/* 浮动积木动画 */
.floating-blocks-anim {
  position: relative;
  width: 160px;
  height: 100px;
  margin: 0 auto;
}

.floating-block {
  position: absolute;
  width: 40px;
  height: 40px;
  border-radius: 8px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  font-size: 1rem;
  color: white;
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.15);
  animation: floatBlock 3s ease-in-out infinite;
}

.floating-block.fb-1 {
  background: linear-gradient(135deg, #64748b, #475569);
  left: 10px;
  top: 20px;
  animation-delay: 0s;
}

.floating-block.fb-2 {
  background: linear-gradient(135deg, #3b82f6, #2563eb);
  left: 60px;
  top: 5px;
  animation-delay: 0.4s;
}

.floating-block.fb-3 {
  background: linear-gradient(135deg, #ef4444, #dc2626);
  left: 110px;
  top: 25px;
  animation-delay: 0.8s;
}

.floating-block.fb-4 {
  background: linear-gradient(135deg, #22c55e, #16a34a);
  left: 60px;
  top: 50px;
  animation-delay: 1.2s;
}

@keyframes floatBlock {

  0%,
  100% {
    transform: translateY(0) rotate(0deg);
  }

  50% {
    transform: translateY(-8px) rotate(3deg);
  }
}

/* Lego Block Enhancement */
.lego-block {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  min-width: 56px;
  min-height: 56px;
  padding: 10px 12px;
  border-radius: 12px;
  font-weight: 700;
  color: white;
  box-shadow:
    inset 0 -3px 0 rgba(0, 0, 0, 0.15),
    inset 0 2px 0 rgba(255, 255, 255, 0.2),
    0 3px 8px rgba(0, 0, 0, 0.1);
  transition:
    transform 0.15s ease,
    box-shadow 0.15s ease;
}

.lego-block:hover {
  transform: translateY(-2px);
  box-shadow:
    inset 0 -3px 0 rgba(0, 0, 0, 0.15),
    inset 0 2px 0 rgba(255, 255, 255, 0.2),
    0 6px 16px rgba(0, 0, 0, 0.15);
}

.lego-block .block-symbol {
  font-size: 1.2rem;
  font-weight: 800;
  line-height: 1;
}

.lego-block .block-count {
  font-size: 0.7rem;
  opacity: 0.85;
  margin-top: 2px;
}

/* Lego Block Colors */
.lego-block.el-C {
  background: linear-gradient(135deg, #374151, #1f2937);
}

.lego-block.el-H {
  background: linear-gradient(135deg, #60a5fa, #3b82f6);
}

.lego-block.el-O {
  background: linear-gradient(135deg, #f87171, #ef4444);
}

.lego-block.el-N {
  background: linear-gradient(135deg, #a78bfa, #8b5cf6);
}

.lego-block.el-S {
  background: linear-gradient(135deg, #fbbf24, #f59e0b);
}

.lego-block.el-P {
  background: linear-gradient(135deg, #fb923c, #f97316);
}

.lego-block.el-Cl {
  background: linear-gradient(135deg, #34d399, #10b981);
}

.lego-block.el-default {
  background: linear-gradient(135deg, #94a3b8, #64748b);
}

/* Lego Group */
.lego-group {
  display: flex;
  align-items: flex-end;
  justify-content: center;
  gap: 6px;
  flex-wrap: wrap;
  padding: 12px;
  background: rgba(255, 255, 255, 0.6);
  border-radius: 12px;
  min-height: 50px;
}

.lego-group-label {
  width: 100%;
  text-align: center;
  font-size: 0.65rem;
  font-weight: 600;
  color: #94a3b8;
  text-transform: uppercase;
  letter-spacing: 0.5px;
  margin-bottom: 6px;
}

/* Multiplier Section */
.multiplier-section {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 8px 16px;
  background: linear-gradient(135deg, #fef3c7, #fde68a);
  border-radius: 12px;
  font-weight: 700;
  color: #92400e;
}

.multiplier-section .times-icon {
  font-size: 1rem;
}

.multiplier-section .multiplier-value {
  font-size: 1.3rem;
  font-weight: 800;
}

.multiplier-section .multiplier-label {
  font-size: 0.7rem;
  opacity: 0.8;
}

/* Molecular Result */
.molecular-result {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 12px 20px;
  background: linear-gradient(135deg, #d1fae5, #a7f3d0);
  border-radius: 12px;
  border: 2px solid #34d399;
}

.molecular-result .result-label {
  font-size: 0.65rem;
  font-weight: 700;
  color: #047857;
  text-transform: uppercase;
}

.molecular-result .result-formula {
  font-size: 1.3rem;
  font-weight: 800;
  color: #065f46;
  font-family: "SF Mono", monospace;
}

/* Lego Block Animation */
@keyframes blockAppear {
  from {
    opacity: 0;
    transform: translateY(20px) scale(0.8);
  }

  to {
    opacity: 1;
    transform: translateY(0) scale(1);
  }
}

.lego-block.animate-in {
  animation: blockAppear 0.4s cubic-bezier(0.34, 1.56, 0.64, 1) forwards;
}

@keyframes multiplierPop {
  0% {
    transform: scale(0);
  }

  50% {
    transform: scale(1.2);
  }

  100% {
    transform: scale(1);
  }
}

.multiplier-section.animate-in {
  animation: multiplierPop 0.5s cubic-bezier(0.34, 1.56, 0.64, 1) forwards;
}

/* Lego Stage States */
.lego-stage.has-result {
  border-style: solid;
  border-color: #a78bfa;
  background: linear-gradient(180deg, #faf5ff, #f5f3ff);
}

/* Calculation Steps Enhancement */
.calc-steps-container {
  margin-top: 12px;
}

.show-calc-btn {
  width: 100%;
  padding: 10px 14px;
  background: #f8fafc;
  color: #475569;
  border: 1px solid #e2e8f0;
  border-radius: 12px;
  font-size: 0.85rem;
  font-weight: 600;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  transition: all 0.15s ease;
}

.show-calc-btn:hover {
  background: #f1f5f9;
  border-color: #cbd5e1;
}

.show-calc-btn svg {
  width: 16px;
  height: 16px;
}

.calc-steps-content {
  background: #ffffff;
  border: 1px solid #e2e8f0;
  border-radius: 12px;
  padding: 14px;
  margin-top: 10px;
  animation: fadeSlideIn 0.2s ease;
}

@keyframes fadeSlideIn {
  from {
    opacity: 0;
    transform: translateY(-6px);
  }

  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.calc-step-row {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 6px 0;
  font-size: 0.9rem;
  color: #475569;
  border-bottom: 1px dashed #f1f5f9;
}

.calc-step-row:last-child {
  border-bottom: none;
  padding-top: 10px;
  margin-top: 6px;
  border-top: 1px solid #e2e8f0;
  font-weight: 700;
  color: #1e293b;
}

/* Enter Hint Enhancement */
.enter-hint {
  display: flex;
  align-items: center;
  justify-content: flex-end;
  gap: 4px;
  margin-top: 8px;
  font-size: 0.8rem;
  color: #475569;
  font-weight: 500;
}

.kbd-key {
  background: #e2e8f0;
  border: 1px solid #cbd5e1;
  border-radius: 4px;
  padding: 2px 8px;
  font-size: 0.75rem;
  font-weight: 600;
  color: #334155;
  box-shadow: 0 1px 0 #94a3b8;
}

/* Scrollbar Styling */
.feature-modal-body::-webkit-scrollbar {
  width: 6px;
}

.feature-modal-body::-webkit-scrollbar-track {
  background: transparent;
}

.feature-modal-body::-webkit-scrollbar-thumb {
  background: #cbd5e1;
  border-radius: 3px;
}

.feature-modal-body::-webkit-scrollbar-thumb:hover {
  background: #94a3b8;
}

.tool-modal-loading {
  min-height: 240px;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 8px;
  color: #64748b;
  font-size: 0.95rem;
  font-weight: 500;
  text-align: center;
}

.tool-modal-loading-error {
  color: #b91c1c;
}