/* Critical CSS - moved to top for faster rendering */

/* Hero Section */
.hero-header {
  background: linear-gradient(135deg, rgba(30, 64, 175, 0.95), rgba(15, 23, 42, 0.95)), 
              radial-gradient(circle at 20% 50%, rgba(59, 130, 246, 0.1) 0%, transparent 50%), 
              radial-gradient(circle at 80% 80%, rgba(37, 99, 235, 0.1) 0%, transparent 50%);
  background-color: #1e40af;
  border-radius: 16px;
  padding: 60px 30px;
  margin-bottom: 40px;
  box-shadow: 0 10px 30px rgba(30, 64, 175, 0.2);
  text-align: center;
}

.hero-subtitle-top {
  color: rgba(255, 255, 255, 0.8);
  font-size: 1rem;
  margin-bottom: 10px;
  text-transform: uppercase;
  letter-spacing: 2px;
}

.hero-title {
  color: white;
  font-size: 2.8rem;
  margin-bottom: 15px;
  font-weight: 700;
  letter-spacing: -0.5px;
}

.hero-description {
  color: rgba(255, 255, 255, 0.9);
  font-size: 1.2rem;
  margin-bottom: 20px;
  max-width: 650px;
  margin-left: auto;
  margin-right: auto;
  line-height: 1.6;
}

.hero-stats {
  display: flex;
  justify-content: center;
  gap: 30px;
  flex-wrap: wrap;
  margin-bottom: 30px;
}

.stat-item {
  text-align: center;
}

.stat-value {
  color: #60a5fa;
  font-size: 2rem;
  font-weight: 700;
}

.stat-label {
  color: rgba(255, 255, 255, 0.7);
  font-size: 0.9rem;
}

.hero-buttons {
  display: flex;
  gap: 15px;
  justify-content: center;
  flex-wrap: wrap;
}

.btn-primary {
  background: linear-gradient(135deg, #3b82f6, #2563eb);
  color: white;
  border: none;
  padding: 16px 32px;
  border-radius: 10px;
  font-size: 1.1rem;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.3s;
  box-shadow: 0 8px 20px rgba(0, 0, 0, 0.15);
}

.btn-primary:hover {
  background: linear-gradient(135deg, #2563eb, #1d4ed8);
  box-shadow: 0 10px 25px rgba(59, 130, 246, 0.4);
}

.btn-secondary {
  background: rgba(255, 255, 255, 0.2);
  color: white;
  border: 2px solid white;
  padding: 14px 30px;
  border-radius: 10px;
  font-size: 1.1rem;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.3s;
  backdrop-filter: blur(10px);
}

.btn-secondary:hover {
  background: rgba(255, 255, 255, 0.3);
}

/* Intro Section */
.intro-section {
  background: linear-gradient(135deg, #ffffff 0%, #f0f9ff 100%);
  border-radius: 16px;
  padding: 45px;
  box-shadow: 0 8px 24px rgba(30, 64, 175, 0.08);
  margin-bottom: 40px;
  border: 1px solid rgba(59, 130, 246, 0.1);
}

.intro-text {
  margin-bottom: 30px;
}

.intro-main {
  font-size: 1.15rem;
  line-height: 1.8;
  color: #1f2937;
  margin-bottom: 20px;
  font-weight: 500;
}

.intro-secondary {
  font-size: 1.05rem;
  line-height: 1.7;
  color: #4b5563;
  margin-bottom: 25px;
}

.video-section {
  margin-bottom: 35px;
  text-align: center;
}

.btn-video {
  background: linear-gradient(135deg, #3b82f6, #2563eb);
  color: white;
  border: none;
  padding: 16px 32px;
  border-radius: 10px;
  font-size: 1.1rem;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.3s;
  box-shadow: 0 6px 20px rgba(59, 130, 246, 0.3);
  display: inline-flex;
  align-items: center;
  gap: 12px;
}

.btn-video:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 15px -3px rgba(0, 0, 0, 0.2);
}

.video-container {
  position: relative;
  width: 100%;
  max-width: 800px;
  margin: 25px auto 0;
  padding-bottom: 56.25%;
  height: 0;
  border-radius: 14px;
  overflow: hidden;
  box-shadow: 0 12px 35px rgba(59, 130, 246, 0.2);
}

.video-container iframe {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  border: none;
}

.target-audience {
  background: linear-gradient(135deg, rgba(59, 130, 246, 0.08), rgba(30, 64, 175, 0.05));
  border-left: 5px solid #3b82f6;
  padding: 28px;
  border-radius: 12px;
  border-top: 1px solid rgba(59, 130, 246, 0.2);
}

.target-audience h3 {
  color: #1e40af;
  margin-bottom: 12px;
  font-size: 1.3rem;
  font-weight: 700;
}

.target-audience p {
  color: #374151;
  line-height: 1.7;
  margin: 0;
  font-size: 1.05rem;
}

/* Interpretation Box */
.interpretation-box {
  margin-top: 15px;
  padding: 15px;
  background: #f1f5f9;
  border-radius: 8px;
}

.interpretation-box h4 {
  color: #1e40af;
  margin-bottom: 10px;
}

.note-italic {
  font-style: italic;
  color: #64748b;
  margin-top: 10px;
}

.expert-box {
  margin-top: 20px;
  padding: 15px;
  background: #e0f2fe;
  border-radius: 8px;
  border-left: 4px solid #0277bd;
}

.expert-box h4 {
  color: #0277bd;
  margin-bottom: 10px;
}

.expert-box a {
  color: #0277bd;
  font-weight: 600;
  text-decoration: none;
}

/* Materials Grid Small for Instructions */
.materials-grid-small {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 10px;
  font-size: 0.9rem;
}

.materials-grid-small ul {
  margin: 5px 0;
  padding-left: 15px;
}

/* Calculator Footer */
.calculator-footer {
  background: #1e3a5f;
  color: white;
  border-radius: 16px;
  padding: 50px 40px 30px;
  margin-top: 50px;
}

.calculator-footer .footer-content {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: 40px;
  margin-bottom: 30px;
}

.calculator-footer .footer-section h3 {
  font-size: 1.2rem;
  margin-bottom: 15px;
  color: white;
}

.calculator-footer .footer-section p {
  color: rgba(255, 255, 255, 0.8);
  line-height: 1.6;
  margin-bottom: 10px;
}

.calculator-footer .footer-section ul {
  list-style: none;
  padding: 0;
  margin: 0;
}

.calculator-footer .footer-section ul li {
  margin-bottom: 8px;
}

.calculator-footer .footer-section ul li a {
  color: rgba(255, 255, 255, 0.8);
  text-decoration: none;
  transition: color 0.2s;
}

.calculator-footer .footer-section ul li a:hover {
  color: #60a5fa;
}

.calculator-footer .footer-section a {
  color: #3b82f6;
}

.footer-note {
  margin-top: 15px;
  font-size: 0.9rem;
}

.calculator-footer .footer-bottom {
  border-top: 1px solid rgba(255, 255, 255, 0.1);
  padding-top: 20px;
  text-align: center;
}

.calculator-footer .footer-bottom p {
  color: rgba(255, 255, 255, 0.7);
  margin-bottom: 8px;
}

.footer-disclaimer {
  font-size: 0.8rem !important;
}

.footer-author {
  font-size: 0.8rem !important;
  color: #6b7280 !important;
}

.footer-author a {
  color: #3b82f6;
}

.footer-dev {
  font-size: 0.8rem !important;
  color: #6b7280 !important;
}

.footer-dev a {
  color: #3b82f6;
}

/* Email Report Section */
.email-report-section {
  margin-top: 30px;
  text-align: center;
}

@media (max-width: 768px) {
  .hero-title {
    font-size: 2rem;
  }
  
  .hero-stats {
    gap: 20px;
  }
  
  .stat-value {
    font-size: 1.5rem;
  }
  
  .intro-section {
    padding: 25px;
  }
  
  .materials-grid-small {
    grid-template-columns: 1fr;
  }
  
  .calculator-footer {
    padding: 30px 20px 20px;
  }
  
  .calculator-footer .footer-content {
    grid-template-columns: 1fr;
    gap: 25px;
  }
}

@keyframes bounceUpDown {
  0%, 100% { transform: translateY(0); }
  50% { transform: translateY(-8px); }
}

#scrollToCalculator {
  outline: none !important;
  -webkit-tap-highlight-color: transparent !important;
  background: linear-gradient(135deg, #3b82f6, #2563eb) !important;
  color: white !important;
  animation: bounceUpDown 2s ease-in-out infinite;
}

#scrollToCalculator:hover {
  outline: none !important;
  background: linear-gradient(135deg, #2563eb, #1d4ed8) !important;
  color: white !important;
  box-shadow: 0 10px 25px rgba(59, 130, 246, 0.4) !important;
}

#scrollToCalculator:focus {
  outline: none !important;
  background: linear-gradient(135deg, #3b82f6, #2563eb) !important;
  color: white !important;
  box-shadow: 0 8px 20px rgba(0, 0, 0, 0.15) !important;
}

#scrollToCalculator:active {
  outline: none !important;
  background: linear-gradient(135deg, #1d4ed8, #1e40af) !important;
  color: white !important;
}

.nav {
  background: white;
  padding: 15px 20px;
  border-radius: 12px;
  box-shadow: 0 2px 4px rgba(0, 0, 0, 0.05);
  margin-bottom: 30px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
}

h1 {
  color: #1e40af;
  margin-bottom: 30px;
  text-align: center;
  font-size: 1.8rem;
  font-weight: 600;
}

.subtitle {
  text-align: center;
  color: #64748b;
  margin-bottom: 30px;
  font-size: 1rem;
}

/* Page-specific styles */

header {
  text-align: left;
  margin-bottom: 15px;
}

header h1 {
  font-size: 1.8rem;
  margin-bottom: 5px;
  color: #1f2937;
}

.subtitle {
  font-size: 0.95rem;
  color: #64748b;
  margin: 0;
  line-height: 1.4;
}

.instructions-card {
  background: white;
  border-radius: 8px;
  padding: 15px;
  box-shadow: 0 2px 4px rgba(0, 0, 0, 0.05);
  margin-bottom: 20px;
  border: 1px solid #e5e7eb;
}

.instructions-header {
  margin-bottom: 15px;
}

.instructions-toggle {
  background: none;
  border: none;
  cursor: pointer;
  width: 100%;
  text-align: left;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 5px 0;
}

.instructions-title {
  color: #1e40af;
  font-size: 1.1rem;
  font-weight: 600;
  margin: 0;
}

.instructions-subtitle {
  color: #64748b;
  font-size: 0.85rem;
  margin: 5px 0 0 0;
  line-height: 1.3;
}

.toggle-icon {
  width: 24px;
  height: 24px;
  transition: transform 0.2s;
}

.toggle-icon.rotated {
  transform: rotate(180deg);
}

.instructions-content {
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.3s ease;
  user-select: text;
  -webkit-user-select: text;
  -moz-user-select: text;
  -ms-user-select: text;
}

.instructions-content.expanded {
  max-height: 5000px;
}

.instructions-grid {
  display: grid;
  gap: 20px;
  margin-top: 20px;
}

.instruction-item {
  padding: 15px;
  background: #f8fafc;
  border-radius: 8px;
  border-left: 4px solid #3b82f6;
  user-select: text;
  -webkit-user-select: text;
  -moz-user-select: text;
  -ms-user-select: text;
}

.instruction-item h3 {
  color: #1f2937;
  margin-bottom: 10px;
  font-size: 1.1rem;
  user-select: text;
  -webkit-user-select: text;
  -moz-user-select: text;
  -ms-user-select: text;
}

.instruction-item ul, .instruction-item ol {
  margin: 10px 0;
  padding-left: 20px;
  user-select: text;
  -webkit-user-select: text;
  -moz-user-select: text;
  -ms-user-select: text;
}

.instruction-item li {
  margin-bottom: 5px;
  user-select: text;
  -webkit-user-select: text;
  -moz-user-select: text;
  -ms-user-select: text;
}

.instruction-item p {
  user-select: text;
  -webkit-user-select: text;
  -moz-user-select: text;
  -ms-user-select: text;
}

.materials-table {
  width: 100%;
  border-collapse: collapse;
  margin: 10px 0;
  font-size: 0.9rem;
}

.materials-table th,
.materials-table td {
  padding: 8px 12px;
  text-align: left;
  border-bottom: 1px solid #e5e7eb;
}

.materials-table th {
  background: #f1f5f9;
  font-weight: 600;
}





@media (max-width: 768px) {
  .footer-content {
    grid-template-columns: 1fr;
    gap: 20px;
  }
}

.modal {
  display: none;
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: rgba(0, 0, 0, 0.5);
  z-index: 2000;
}

.modal.active {
  display: flex;
  align-items: center;
  justify-content: center;
}

.modal-content {
  background: white;
  border-radius: 12px;
  padding: 30px;
  max-width: 500px;
  width: 90%;
  max-height: 90vh;
  overflow-y: auto;
  position: relative;
}

.modal-close {
  position: absolute;
  top: 15px;
  right: 20px;
  background: none;
  border: none;
  font-size: 24px;
  cursor: pointer;
  color: #64748b;
}

.modal h2 {
  color: #1e40af;
  margin-bottom: 20px;
}

.form-group-modal {
  margin-bottom: 20px;
}

.form-group-modal label {
  display: block;
  margin-bottom: 8px;
  font-weight: 500;
  color: #374151;
}

.form-group-modal input,
.form-group-modal textarea {
  width: 100%;
  padding: 12px;
  border: 2px solid #e5e7eb;
  border-radius: 8px;
  font-size: 16px;
  transition: border-color 0.2s;
}

.form-group-modal textarea {
  height: 120px;
  resize: vertical;
}

.form-group-modal input:focus,
.form-group-modal textarea:focus {
  outline: none;
  border-color: #3b82f6;
}

.submit-btn {
  background: #3b82f6;
  color: white;
  border: none;
  padding: 12px 24px;
  border-radius: 8px;
  font-weight: 600;
  cursor: pointer;
  width: 100%;
}

.submit-btn:hover {
  background: #2563eb;
}

.submit-btn:disabled {
  background: #9ca3af;
  cursor: not-allowed;
}

.email-report-btn {
  background: #059669;
  color: white;
  border: none;
  padding: 15px 30px;
  border-radius: 8px;
  font-weight: 600;
  font-size: 16px;
  cursor: pointer;
  transition: background 0.2s;
}

.email-report-btn:hover {
  background: #047857;
}

.email-report-btn:disabled {
  background: #9ca3af;
  cursor: not-allowed;
}

.calc-modal {
  max-width: 800px;
  max-height: 80vh;
}

.calculation-steps {
  margin-top: 20px;
}

.calculation-step {
  background: #f8fafc;
  border: 1px solid #e2e8f0;
  border-radius: 8px;
  padding: 15px;
  margin-bottom: 10px;
}

.step-title {
  font-weight: 600;
  color: #1e40af;
  margin-bottom: 8px;
}

.step-formula {
  font-family: 'Courier New', monospace;
  background: #f1f5f9;
  padding: 8px;
  border-radius: 4px;
  margin: 8px 0;
  font-size: 14px;
}

.step-result {
  font-weight: 500;
  color: #059669;
}

.details-btn {
  background: #64748b;
  color: white;
  border: none;
  padding: 4px 8px;
  border-radius: 4px;
  font-size: 12px;
  cursor: pointer;
}

.details-btn:hover {
  background: #475569;
}

.formula-preview {
  position: fixed;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  background: white;
  border: 2px solid #3b82f6;
  border-radius: 12px;
  padding: 20px;
  box-shadow: 0 10px 25px rgba(0, 0, 0, 0.3);
  z-index: 1000;
  max-width: 500px;
  max-height: 80vh;
  overflow-y: auto;
  display: none;
}

.formula-preview h3 {
  color: #1e40af;
  margin-bottom: 15px;
  text-align: center;
}

.formula-step {
  background: #f8fafc;
  border: 1px solid #e2e8f0;
  border-radius: 6px;
  padding: 10px;
  margin-bottom: 8px;
}

.formula-step .step-name {
  font-weight: 600;
  color: #374151;
  margin-bottom: 5px;
}

.formula-step .step-calc {
  font-family: 'Courier New', monospace;
  background: #f1f5f9;
  padding: 5px;
  border-radius: 3px;
  font-size: 14px;
}

.formula-icon {
  display: inline-block;
  margin-left: 8px;
  padding: 4px 8px;
  background: #9ca3af;
  color: white;
  border-radius: 50%;
  cursor: pointer;
  font-size: 14px;
  font-weight: bold;
  transition: all 0.2s;
}

.formula-icon:hover {
  background: #6b7280;
  transform: scale(1.1);
}

.input-with-formula {
  position: relative;
  display: flex;
  align-items: center;
}

.input-with-formula input {
  flex: 1;
}

.preview-overlay {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: rgba(0, 0, 0, 0.5);
  z-index: 999;
  display: none;
}

.close-preview {
  position: absolute;
  top: 10px;
  right: 15px;
  background: none;
  border: none;
  font-size: 20px;
  cursor: pointer;
  color: #64748b;
}

h1 {
  color: #1e40af;
  margin-bottom: 10px;
  text-align: center;
  font-size: 1.8rem;
}

.subtitle {
  text-align: center;
  color: #64748b;
  margin-bottom: 30px;
}

.form-card {
  background: white;
  border-radius: 12px;
  padding: 30px;
  box-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
  margin-bottom: 30px;
}

.form-group {
  margin-bottom: 20px;
}

label {
  display: block;
  margin-bottom: 8px;
  font-weight: 500;
  color: #374151;
}

input, select {
  width: 100%;
  padding: 12px;
  border: 2px solid #e5e7eb;
  border-radius: 8px;
  font-size: 16px;
  transition: border-color 0.2s;
}

input:focus, select:focus {
  outline: none;
  border-color: #3b82f6;
}

fieldset {
  border: 2px solid #e5e7eb;
  border-radius: 8px;
  padding: 20px;
  margin-bottom: 20px;
}

legend {
  padding: 0 10px;
  font-weight: 600;
  color: #1f2937;
}

.wall-layer-header, .climate-header {
  display: grid;
  grid-template-columns: 1fr 1fr 1fr auto;
  gap: 10px;
  margin-bottom: 10px;
  padding: 0 0 8px 0;
  border-bottom: 2px solid #e5e7eb;
  font-weight: 600;
  color: #374151;
  font-size: 0.9rem;
}

.wall-layer, .climate-row {
  display: grid;
  grid-template-columns: 1fr 1fr 1fr auto;
  gap: 10px;
  margin-bottom: 15px;
  align-items: center;
  background: #f8fafc;
  padding: 15px;
  border-radius: 8px;
  border: 1px solid #e5e7eb;
}

.remove-btn {
  background: transparent;
  color: #dc2626;
  border: 1px solid #fecaca;
  padding: 6px 8px;
  border-radius: 4px;
  cursor: pointer;
  font-size: 16px;
  transition: all 0.2s;
  width: 32px;
  height: 32px;
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
  justify-self: end;
}

.remove-btn:hover {
  background: #fef2f2;
  color: #b91c1c;
  border-color: #fca5a5;
}

.add-btn {
  background: transparent;
  color: #10b981;
  border: 2px solid #10b981;
  padding: 10px 20px;
  border-radius: 6px;
  cursor: pointer;
  font-weight: 500;
  transition: all 0.2s;
}

.add-btn:hover {
  background: #10b981;
  color: white;
}

.calculate-btn {
  background: #3b82f6;
  color: white;
  border: none;
  padding: 15px 30px;
  border-radius: 8px;
  font-size: 18px;
  font-weight: 600;
  cursor: pointer;
  width: 100%;
  margin-top: 20px;
}

.calculate-btn:hover {
  background: #2563eb;
}

.results {
  background: white;
  border-radius: 12px;
  padding: 30px;
  box-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
  margin-top: 30px;
}

table {
  width: 100%;
  border-collapse: collapse;
  margin-bottom: 30px;
}

th, td {
  padding: 12px;
  text-align: left;
  border-bottom: 1px solid #e5e7eb;
}

th {
  background: #f8fafc;
  font-weight: 600;
  color: #374151;
}

.chart-container {
  margin-top: 30px;
  height: 400px;
}

.notification {
  position: fixed;
  top: 20px;
  right: 20px;
  padding: 15px 20px;
  border-radius: 8px;
  color: white;
  font-weight: 500;
  z-index: 1000;
  animation: slideIn 0.3s ease;
}

.notification.success { background: #10b981; }
.notification.error { background: #ef4444; }

@keyframes slideIn {
  from { transform: translateX(100%); }
  to { transform: translateX(0); }
}

.two-column {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 20px;
}

.progress-steps {
  display: flex;
  justify-content: space-between;
  margin-bottom: 30px;
  padding: 0 10px;
  margin-top: 20px;
}

.progress-step {
  display: flex;
  flex-direction: column;
  align-items: center;
  flex: 1;
  position: relative;
}

.progress-step:not(:last-child)::after {
  content: '';
  position: absolute;
  top: 15px;
  left: 50%;
  width: 100%;
  height: 3px;
  background: #e5e7eb;
  z-index: 0;
}

.progress-step.completed:not(:last-child)::after {
  background: #10b981;
}

.progress-step.active:not(:last-child)::after {
  background: linear-gradient(90deg, #10b981 0%, #e5e7eb 100%);
}

.step-number {
  width: 32px;
  height: 32px;
  border-radius: 50%;
  background: #e5e7eb;
  color: #9ca3af;
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 600;
  font-size: 14px;
  position: relative;
  z-index: 1;
  transition: all 0.3s ease;
}

.progress-step.active .step-number {
  background: #3b82f6;
  color: white;
  box-shadow: 0 0 0 4px rgba(59, 130, 246, 0.2);
}

.progress-step.completed .step-number {
  background: #10b981;
  color: white;
}

.progress-step.completed .step-number::after {
  content: '✓';
}

.step-label {
  margin-top: 8px;
  font-size: 12px;
  color: #9ca3af;
  font-weight: 500;
  text-align: center;
}

.progress-step.active .step-label,
.progress-step.completed .step-label {
  color: #374151;
}

.calc-section {
  border: 2px solid #e5e7eb;
  border-radius: 12px;
  margin-bottom: 16px;
  overflow: hidden;
  transition: all 0.3s ease;
}

.calc-section.active {
  border-color: #3b82f6;
  box-shadow: 0 4px 12px rgba(59, 130, 246, 0.15);
}

.calc-section.completed {
  border-color: #10b981;
}

.calc-section.locked {
  opacity: 0.6;
}

.section-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 16px 20px;
  background: #f8fafc;
  cursor: pointer;
  user-select: none;
  transition: background 0.2s;
}

.calc-section.active .section-header {
  background: #eff6ff;
}

.calc-section.completed .section-header {
  background: #ecfdf5;
}

.calc-section.locked .section-header {
  cursor: not-allowed;
}

.section-header:hover:not(.locked .section-header) {
  background: #f1f5f9;
}

.section-title {
  display: flex;
  align-items: center;
  gap: 10px;
  font-weight: 600;
  color: #374151;
  font-size: 1rem;
}

.section-icon {
  font-size: 1.2rem;
}

.section-status {
  font-size: 1.2rem;
}

.section-content {
  padding: 0 20px;
  max-height: 0;
  overflow: hidden;
  transition: all 0.3s ease;
}

.calc-section.active .section-content,
.calc-section.completed .section-content {
  max-height: 2000px;
  padding: 20px;
}

.calc-section.locked .section-content {
  display: none;
}

@media (max-width: 768px) {
  header h1 {
    font-size: 1.5rem;
  }
  
  .subtitle {
    font-size: 0.9rem;
  }
  
  .instructions-title {
    font-size: 1rem;
  }
  
  .two-column {
    grid-template-columns: 1fr;
  }
  
  .progress-steps {
    padding: 0 5px;
  }
  
  .step-number {
    width: 28px;
    height: 28px;
    font-size: 12px;
  }
  
  .step-label {
    font-size: 10px;
  }
  
  .progress-step:not(:last-child)::after {
    top: 13px;
  }
  
  .section-title {
    font-size: 0.9rem;
  }
  
  .section-header {
    padding: 12px 15px;
  }
  
  .calc-section.active .section-content,
  .calc-section.completed .section-content {
    padding: 15px;
  }
  
  .wall-layer-header, .climate-header {
    display: none;
  }

  .wall-layer, .climate-row {
    display: block;
    gap: 0;
    padding: 20px;
    margin-bottom: 20px;
    position: relative;
  }
  
  .wall-layer .layer-material,
  .wall-layer .layer-thickness,
  .wall-layer .layer-lambda,
  .climate-row .month-name,
  .climate-row .month-temp,
  .climate-row .month-days {
    width: 100%;
    margin-bottom: 15px;
    position: relative;
  }

  .wall-layer .layer-material::before {
    content: "Назва матеріалу:";
    display: block;
    font-weight: 600;
    color: #374151;
    margin-bottom: 5px;
    font-size: 14px;
  }

  .wall-layer .layer-thickness::before {
    content: "Товщина (м):";
    display: block;
    font-weight: 600;
    color: #374151;
    margin-bottom: 5px;
    font-size: 14px;
  }

  .wall-layer .layer-lambda::before {
    content: "Коефіцієнт теплопровідності λ (Вт/м·К):";
    display: block;
    font-weight: 600;
    color: #374151;
    margin-bottom: 5px;
    font-size: 14px;
  }

  .climate-row .month-name::before {
    content: "Період:";
    display: block;
    font-weight: 600;
    color: #374151;
    margin-bottom: 5px;
    font-size: 14px;
  }

  .climate-row .month-temp::before {
    content: "Середня температура (°C):";
    display: block;
    font-weight: 600;
    color: #374151;
    margin-bottom: 5px;
    font-size: 14px;
  }

  .climate-row .month-days::before {
    content: "Тривалість опалення (днів):";
    display: block;
    font-weight: 600;
    color: #374151;
    margin-bottom: 5px;
    font-size: 14px;
  }
  
  .remove-btn {
    position: absolute;
    top: 15px;
    right: 15px;
    margin: 0;
  }
}