/* Base design system - clean, readable, responsive */
* { 
    box-sizing: border-box; 
}
html, body { 
    height: 100%; 
}

:root {
  /* Palette */
  --bg: #0F172A;           /* slate-900 */
  --surface: #111827;      /* gray-900 */
  --surface-2: #0B1220;    /* deep surface */
  --card: #FFFFFF;         /* light card for contrast */
  --text: #0F172A;         /* dark text on light card */
  --muted: #334155;        /* slate-700 */
  --muted-2: #475569;      /* slate-600 */
  --primary: #2563EB;      /* blue-600 */
  --primary-700: #1D4ED8;  /* blue-700 */
  --success: #16A34A;      /* green-600 */
  --warning: #F59E0B;      /* amber-500 */
  --danger: #DC2626;       /* red-600 */
  --border: #E5E7EB;       /* gray-200 for cards */
  --shadow: 0 8px 24px rgba(2,6,23,0.08);
  --radius: 14px;
}

/* App background is dark, cards are light for readability */
body {
  font-family: 'Inter', system-ui, -apple-system, Segoe UI, Roboto, Ubuntu, Cantarell, 'Helvetica Neue', Arial, sans-serif;
  background: linear-gradient(180deg, var(--bg) 0%, var(--surface) 100%);
  color: #E5E7EB; /* light text on dark background */
  margin: 0;
  line-height: 1.6;
  padding-bottom: 84px; /* space for bottom nav */
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  min-height: 100vh;
  overflow-x: hidden;
}

.app-header {
  position: sticky; 
  top: 0; 
  z-index: 1000;
  background: linear-gradient(135deg, rgba(15,23,42,0.98), rgba(17,24,39,0.95));
  backdrop-filter: blur(24px);
  border-bottom: 2px solid rgba(37,99,235,0.2);
  padding: 20px 24px; 
  text-align: center;
  transition: all 0.3s ease;
  box-shadow: 0 4px 20px rgba(0,0,0,0.1);
  display: flex;
  flex-direction: column;
  align-items: center;
}
.app-header h1 { 
  margin: 0 0 12px; 
  font-size: 24px; 
  font-weight: 800; 
  letter-spacing: -0.02em; 
  color: #FFF; 
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 12px;
  text-shadow: 0 2px 4px rgba(0,0,0,0.3);
}
.app-header h1 i {
  color: #60A5FA;
  filter: drop-shadow(0 2px 4px rgba(96,165,250,0.3));
}

.header-logo {
  height: 32px;
  width: auto;
  filter: drop-shadow(0 2px 4px rgba(0,0,0,0.3));
  transition: transform 0.3s ease;
}

.header-logo:hover {
  transform: scale(1.05);
}

.deadline-alert {
  display: inline-flex; 
  align-items: center; 
  gap: 10px;
  background: linear-gradient(135deg, rgba(245,158,11,0.2), rgba(217,119,6,0.15));
  color: #FFE8B0; 
  border: 2px solid rgba(245,158,11,0.4);
  padding: 12px 20px; 
  border-radius: 16px; 
  font-weight: 700; 
  font-size: 15px;
  margin-top: 12px;
  animation: pulse 2s infinite;
  width: auto;
  max-width: fit-content;
  word-wrap: break-word;
  box-shadow: 0 4px 16px rgba(245,158,11,0.2);
  backdrop-filter: blur(10px);
  position: relative;
  overflow: hidden;
  text-align: center;
}
.deadline-alert::before {
  content: '';
  position: absolute;
  top: 0;
  left: -100%;
  width: 100%;
  height: 100%;
  background: linear-gradient(90deg, transparent, rgba(255,255,255,0.2), transparent);
  animation: slide 3s infinite;
}
.deadline-alert.critical { 
  background: linear-gradient(135deg, rgba(220,38,38,0.25), rgba(185,28,28,0.2));
  color: #FFC5C5; 
  border-color: rgba(220,38,38,0.5);
  animation: pulse 1s infinite;
  box-shadow: 0 4px 16px rgba(220,38,38,0.3);
}
@keyframes slide {
  0% { left: -100%; }
  100% { left: 100%; }
}

@keyframes pulse {
  0%, 100% { opacity: 1; }
  50% { opacity: 0.8; }
}

/* Important notice */
.important-notice {
  background: linear-gradient(135deg, #fef3c7, #fde68a, #fbbf24);
  border: 3px solid #f59e0b;
  border-radius: 16px;
  padding: 20px 24px;
  margin-bottom: 24px;
  color: #92400e;
  font-size: 16px;
  line-height: 1.7;
  position: relative;
  overflow: hidden;
  animation: slideIn 0.6s ease-out;
  box-shadow: 0 8px 32px rgba(245,158,11,0.2);
  backdrop-filter: blur(10px);
}
.important-notice::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 4px;
  background: linear-gradient(90deg, #f59e0b, #d97706, #f59e0b, #b45309);
  animation: shimmer 3s infinite;
}
.important-notice::after {
  content: '⚠️';
  position: absolute;
  top: 16px;
  right: 20px;
  font-size: 24px;
  opacity: 0.3;
  animation: pulse 2s infinite;
}
.important-notice strong {
  color: #b45309;
  font-weight: 800;
  font-size: 17px;
  display: block;
  margin-bottom: 8px;
  text-shadow: 0 1px 2px rgba(180,83,9,0.3);
}
.important-notice span {
  display: block;
  color: #92400e;
  font-weight: 500;
  line-height: 1.6;
}
@keyframes shimmer {
  0% { transform: translateX(-100%); }
  100% { transform: translateX(100%); }
}

.app-main { 
  padding: 20px 16px; 
  max-width: 1200px; 
  margin: 0 auto; 
}
.container { 
  max-width: 900px; 
  margin: 0 auto; 
  padding: 0 4px;
}

/* Cards: light on dark for maximum contrast */
.card {
  background: var(--card);
  color: var(--text);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  padding: 24px;
  margin-bottom: 20px;
  transition: all 0.3s ease;
  position: relative;
  overflow: hidden;
}
.card:hover {
  transform: translateY(-2px);
  box-shadow: 0 12px 32px rgba(2,6,23,0.12);
}
.card h2, .card h3 { 
  margin: 0 0 16px; 
  font-size: 22px; 
  font-weight: 800; 
  letter-spacing: -0.01em; 
  color: var(--primary);
  display: flex;
  align-items: center;
  gap: 8px;
}
.card p { 
  color: var(--muted); 
  line-height: 1.7;
  margin-bottom: 12px;
}

/* Sections */
.section { 
  display: none; 
  animation: fadeIn 0.5s ease-out; 
  opacity: 0;
  transform: translateY(20px);
}
.section.active { 
  display: block; 
  opacity: 1;
  transform: translateY(0);
  min-height: auto;
}
@keyframes fadeIn { 
  from { 
    opacity: 0; 
    transform: translateY(20px);
  } 
  to { 
    opacity: 1; 
    transform: translateY(0);
  } 
}

/* Global animations */
@keyframes bounce {
  0%, 20%, 50%, 80%, 100% {
    transform: translateY(0);
  }
  40% {
    transform: translateY(-10px);
  }
  60% {
    transform: translateY(-5px);
  }
}

@keyframes glow {
  0%, 100% {
    box-shadow: 0 0 5px rgba(37,99,235,0.3);
  }
  50% {
    box-shadow: 0 0 20px rgba(37,99,235,0.6);
  }
}

.animate-bounce {
  animation: bounce 1s infinite;
}

.animate-glow {
  animation: glow 2s infinite;
}

/* Forms */
.calculator-form { 
  display: grid; 
  gap: 18px; 
  margin-top: 8px;
}
.form-group { 
  display: grid; 
  gap: 10px; 
  position: relative;
}
.form-group label { 
  font-weight: 600; 
  color: var(--muted-2); 
  font-size: 15px;
  display: flex;
  align-items: center;
  gap: 6px;
}
.form-group input, .form-group select {
  appearance: none;
  padding: 16px 20px;
  border: 3px solid #E2E8F0;
  border-radius: 16px;
  font-size: 16px; 
  color: var(--text);
  background: #FFFFFF;
  transition: all 0.4s ease;
  width: 100%;
  position: relative;
  box-shadow: 0 4px 16px rgba(0,0,0,0.05);
}
.form-group input:focus, .form-group select:focus {
  outline: none; 
  border-color: var(--primary); 
  box-shadow: 0 0 0 4px rgba(37,99,235,0.15), 0 8px 24px rgba(37,99,235,0.1);
  transform: translateY(-2px);
  background: #F8FAFF;
}
.form-group input:hover, .form-group select:hover {
  border-color: var(--primary);
  transform: translateY(-1px);
  box-shadow: 0 6px 20px rgba(0,0,0,0.08);
}
.form-group input::placeholder {
  color: #94A3B8;
  font-weight: 500;
}
.error { 
  border-color: var(--danger) !important; 
  background: #FEF2F2 !important; 
  animation: shake 0.5s ease-in-out;
}

@keyframes shake {
  0%, 100% { transform: translateX(0); }
  25% { transform: translateX(-4px); }
  75% { transform: translateX(4px); }
}

/* Radio group */
.tax-model-selector {
  background: linear-gradient(135deg, #F8FAFC, #F1F5F9);
  border: 3px solid #E2E8F0;
  border-radius: 20px;
  padding: 24px;
  margin: 24px 0;
  position: relative;
  overflow: hidden;
  box-shadow: 0 8px 32px rgba(0,0,0,0.05);
}
.tax-model-selector::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 4px;
  background: linear-gradient(90deg, var(--primary), #60A5FA, var(--primary));
}
.tax-model-selector h3 {
  margin: 0 0 20px;
  color: var(--primary);
  font-size: 20px;
  font-weight: 800;
  display: flex;
  align-items: center;
  gap: 10px;
}
.tax-model-selector h3::before {
  content: '⚖️';
  font-size: 24px;
}
.radio-group { 
  display: grid; 
  gap: 16px; 
  grid-template-columns: 1fr 1fr;
}
.radio-label {
  display: flex; 
  align-items: center; 
  gap: 14px;
  padding: 20px 24px; 
  border: 3px solid #E2E8F0; 
  border-radius: 16px; 
  cursor: pointer; 
  background: #FFF;
  transition: all 0.4s ease;
  position: relative;
  overflow: hidden;
  box-shadow: 0 4px 16px rgba(0,0,0,0.05);
}
.radio-label::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: linear-gradient(135deg, transparent, rgba(37,99,235,0.05));
  opacity: 0;
  transition: opacity 0.3s ease;
}
.radio-label:hover { 
  border-color: var(--primary); 
  background: #F8FAFF; 
  transform: translateY(-4px);
  box-shadow: 0 8px 24px rgba(37,99,235,0.15);
}
.radio-label:hover::before {
  opacity: 1;
}
.radio-label input[type="radio"] { 
  width: 22px; 
  height: 22px; 
  accent-color: var(--primary);
  position: relative;
  z-index: 2;
}
.radio-label input[type="radio"]:checked + span { 
  color: var(--primary); 
  font-weight: 800; 
  font-size: 16px;
}
.radio-label:has(input[type="radio"]:checked) {
  border-color: var(--primary);
  background: linear-gradient(135deg, rgba(37,99,235,0.08), rgba(96,165,250,0.05));
  box-shadow: 0 0 0 3px rgba(37,99,235,0.15), 0 8px 24px rgba(37,99,235,0.2);
  transform: translateY(-2px);
}
.radio-label span {
  position: relative;
  z-index: 2;
  font-weight: 600;
  font-size: 15px;
}

/* Buttons */
.btn-primary, .btn-secondary, .btn-danger {
  display: inline-flex; 
  align-items: center; 
  justify-content: center; 
  gap: 10px;
  padding: 16px 24px; 
  border-radius: 12px; 
  font-weight: 700; 
  font-size: 16px;
  border: none; 
  cursor: pointer; 
  box-shadow: var(--shadow);
  transition: all 0.3s ease;
  position: relative;
  overflow: hidden;
  min-height: 52px;
}
.btn-primary { 
  background: linear-gradient(135deg, var(--primary), var(--primary-700)); 
  color: #FFF; 
}
.btn-primary:hover { 
  background: linear-gradient(135deg, var(--primary-700), #1E40AF); 
  transform: translateY(-2px);
  box-shadow: 0 8px 24px rgba(37,99,235,0.3);
}
.btn-secondary { 
  background: linear-gradient(135deg, var(--success), #15803D); 
  color: #FFF; 
}
.btn-secondary:hover { 
  background: linear-gradient(135deg, #15803D, #166534); 
  transform: translateY(-2px);
  box-shadow: 0 8px 24px rgba(22,163,74,0.3);
}
.btn-danger { 
  background: linear-gradient(135deg, var(--danger), #B91C1C); 
  color: #FFF; 
}
.btn-danger:hover { 
  background: linear-gradient(135deg, #B91C1C, #991B1B); 
  transform: translateY(-2px);
  box-shadow: 0 8px 24px rgba(220,38,38,0.3);
}

/* Results */
.results-container {
  margin-top: 24px;
  animation: slideIn 0.5s ease-out;
}
.results-grid { 
  display: grid; 
  grid-template-columns: 1fr; 
  gap: 12px; 
  margin-bottom: 20px;
}
.result-item { 
  display: grid; 
  grid-template-columns: 1.2fr 0.8fr; 
  gap: 16px; 
  align-items: center; 
  background: #F8FAFC; 
  border: 2px solid #E2E8F0; 
  border-radius: 12px; 
  padding: 16px 20px; 
  transition: all 0.3s ease;
  position: relative;
  overflow: hidden;
}
.result-item:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 24px rgba(0,0,0,0.1);
  border-color: var(--primary);
}
.result-item.highlight {
  background: linear-gradient(135deg, #F0F9FF, #E0F2FE);
  border-color: var(--primary);
  box-shadow: 0 4px 16px rgba(37,99,235,0.1);
}
.result-label { 
  color: var(--muted-2); 
  font-weight: 600; 
  font-size: 15px;
}
.result-value { 
  text-align: right; 
  font-weight: 800; 
  color: var(--text); 
  font-size: 18px;
}
.result-value.positive { 
  color: #16A34A; 
  font-size: 20px;
}
.result-value.negative { 
  color: #DC2626; 
  font-size: 20px;
}
.result-value.neutral { 
  color: var(--primary); 
  font-size: 20px;
}

@keyframes slideIn {
  from { 
    opacity: 0; 
    transform: translateY(20px); 
  }
  to { 
    opacity: 1; 
    transform: translateY(0); 
  }
}

/* Comparison */
.comparison-container {
  margin-top: 24px;
  animation: slideIn 0.5s ease-out;
}
.comparison-grid { 
  display: grid; 
  grid-template-columns: 1fr; 
  gap: 24px; 
  margin-bottom: 24px;
}
.comparison-item { 
  background: linear-gradient(135deg, #F8FAFC, #FFFFFF); 
  border: 3px solid #E2E8F0; 
  border-radius: 20px; 
  padding: 24px; 
  transition: all 0.4s ease;
  position: relative;
  overflow: hidden;
  box-shadow: 0 4px 16px rgba(0,0,0,0.05);
}
.comparison-item::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 4px;
  background: linear-gradient(90deg, var(--primary), #60A5FA, var(--success));
  opacity: 0;
  transition: opacity 0.3s ease;
}
.comparison-item:hover {
  transform: translateY(-4px);
  box-shadow: 0 12px 32px rgba(0,0,0,0.12);
  border-color: var(--primary);
}
.comparison-item:hover::before {
  opacity: 1;
}
.comparison-item h4 {
  margin: 0 0 20px;
  color: var(--primary);
  font-size: 20px;
  font-weight: 800;
  display: flex;
  align-items: center;
  gap: 12px;
}
.comparison-item h4::before {
  content: '💰';
  font-size: 24px;
}
.savings-analysis {
  background: linear-gradient(135deg, #F0F9FF, #E0F2FE);
  border: 3px solid var(--primary);
  border-radius: 16px;
  padding: 20px;
  margin-top: 20px;
  position: relative;
  overflow: hidden;
  box-shadow: 0 4px 16px rgba(37,99,235,0.1);
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 16px;
  flex-wrap: wrap;
}
.savings-analysis::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: linear-gradient(90deg, var(--primary), #60A5FA, var(--success));
}
.savings-positive {
  color: #16A34A;
  font-weight: 800;
  font-size: 18px;
  display: flex;
  align-items: center;
  gap: 8px;
  flex: 1;
  min-width: 200px;
  text-align: center;
}
.savings-positive::before {
  content: '📈';
  font-size: 20px;
}
.savings-negative {
  color: #DC2626;
  font-weight: 800;
  font-size: 18px;
  display: flex;
  align-items: center;
  gap: 8px;
  flex: 1;
  min-width: 200px;
  text-align: center;
}
.savings-negative::before {
  content: '📉';
  font-size: 20px;
}
.savings-neutral {
  color: var(--primary);
  font-weight: 800;
  font-size: 18px;
  display: flex;
  align-items: center;
  gap: 8px;
  flex: 1;
  min-width: 200px;
  text-align: center;
}
.savings-neutral::before {
  content: '⚖️';
  font-size: 20px;
}

/* History */
.history-list { 
  max-height: 600px; 
  overflow-y: auto; 
  padding-right: 12px;
  margin-top: 8px;
}
.history-list::-webkit-scrollbar {
  width: 8px;
}
.history-list::-webkit-scrollbar-track {
  background: #F1F5F9;
  border-radius: 4px;
}
.history-list::-webkit-scrollbar-thumb {
  background: linear-gradient(180deg, var(--primary), #60A5FA);
  border-radius: 4px;
}
.history-list::-webkit-scrollbar-thumb:hover {
  background: linear-gradient(180deg, var(--primary-700), var(--primary));
}
.history-item { 
  background: linear-gradient(135deg, #F8FAFC, #FFFFFF); 
  border: 3px solid #E2E8F0; 
  border-radius: 16px; 
  padding: 20px; 
  margin-bottom: 16px; 
  transition: all 0.4s ease;
  position: relative;
  overflow: hidden;
  box-shadow: 0 4px 16px rgba(0,0,0,0.05);
}
.history-item::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 4px;
  background: linear-gradient(90deg, var(--primary), #60A5FA, var(--success));
  opacity: 0;
  transition: opacity 0.3s ease;
}
.history-item:hover {
  transform: translateY(-4px);
  box-shadow: 0 12px 32px rgba(0,0,0,0.12);
  border-color: var(--primary);
}
.history-item:hover::before {
  opacity: 1;
}
.history-item-header { 
  display: flex; 
  justify-content: space-between; 
  align-items: center; 
  margin-bottom: 16px; 
  padding-bottom: 12px;
  border-bottom: 2px solid #F1F5F9;
}
.history-item-date { 
  font-size: 15px; 
  color: var(--muted-2); 
  font-weight: 700;
  display: flex;
  align-items: center;
  gap: 8px;
}
.history-item-date::before {
  content: '📅';
  font-size: 16px;
}
.history-item-delete { 
  background: linear-gradient(135deg, #FEE2E2, #FECACA); 
  border: 2px solid #FCA5A5; 
  color: var(--danger); 
  cursor: pointer; 
  border-radius: 12px; 
  padding: 10px 12px; 
  transition: all 0.3s ease;
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 600;
  box-shadow: 0 2px 8px rgba(220,38,38,0.1);
}
.history-item-delete:hover { 
  background: linear-gradient(135deg, #FECACA, #FCA5A5); 
  transform: scale(1.05);
  box-shadow: 0 4px 16px rgba(220,38,38,0.2);
}
.history-item-content {
  display: grid;
  gap: 12px;
}
.history-item-content p {
  margin: 0;
  font-size: 15px;
  color: var(--muted-2);
  line-height: 1.6;
  font-weight: 500;
}
.history-item-content strong {
  color: var(--primary);
  font-weight: 700;
}
.empty-state { 
  text-align: center; 
  color: var(--muted-2); 
  padding: 60px 20px; 
  font-style: italic; 
  font-size: 18px;
  background: linear-gradient(135deg, #F8FAFC, #F1F5F9);
  border: 3px dashed #E2E8F0;
  border-radius: 16px;
  position: relative;
  overflow: hidden;
}
.empty-state::before {
  content: '📊';
  font-size: 48px;
  display: block;
  margin-bottom: 16px;
  opacity: 0.5;
}

/* FAQ */
.faq-container { 
  display: grid; 
  gap: 16px; 
  margin-top: 8px;
}
.faq-item { 
  border: 2px solid #E2E8F0; 
  border-radius: 16px; 
  overflow: hidden; 
  background: #FFF; 
  transition: all 0.3s ease;
  box-shadow: 0 2px 8px rgba(0,0,0,0.05);
}
.faq-item:hover {
  border-color: var(--primary);
  box-shadow: 0 8px 24px rgba(37,99,235,0.1);
}
.faq-question { 
  width: 100%; 
  background: #FFF; 
  border: none; 
  padding: 20px; 
  text-align: left; 
  cursor: pointer; 
  display: flex; 
  justify-content: space-between; 
  align-items: center; 
  font-weight: 700; 
  color: var(--text); 
  font-size: 16px;
  transition: all 0.3s ease;
}
.faq-question:hover {
  background: #F8FAFF;
}
.faq-question[aria-expanded="true"] { 
  background: #F0F9FF; 
  color: var(--primary); 
}
.faq-answer { 
  background: #F8FAFC; 
  padding: 20px; 
  border-top: 2px solid #E2E8F0; 
  font-size: 15px;
  line-height: 1.7;
  color: var(--muted-2);
}
.faq-icon {
  transition: transform 0.3s ease;
  font-size: 18px;
}
.faq-question[aria-expanded="true"] .faq-icon {
  transform: rotate(45deg);
}

/* Sources */
.source-list { 
  list-style: none; 
  padding: 0; 
  margin: 0; 
  display: grid;
  gap: 16px;
}
.source-list li { 
  background: linear-gradient(135deg, #F8FAFC, #FFFFFF); 
  border: 3px solid #E2E8F0; 
  border-radius: 16px; 
  padding: 20px; 
  transition: all 0.4s ease;
  position: relative;
  overflow: hidden;
  box-shadow: 0 4px 16px rgba(0,0,0,0.05);
}
.source-list li::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 4px;
  background: linear-gradient(90deg, var(--primary), #60A5FA, var(--success));
  opacity: 0;
  transition: opacity 0.3s ease;
}
.source-list li:hover {
  border-color: var(--primary);
  transform: translateY(-4px);
  box-shadow: 0 12px 32px rgba(37,99,235,0.15);
}
.source-list li:hover::before {
  opacity: 1;
}
.source-list a { 
  color: var(--primary); 
  text-decoration: none; 
  font-weight: 700; 
  font-size: 16px;
  display: flex;
  align-items: center;
  gap: 12px;
  transition: all 0.3s ease;
  line-height: 1.6;
}
.source-list a:hover { 
  color: var(--primary-700);
  text-decoration: underline; 
  transform: translateX(4px);
}
.source-list a::before {
  content: "🔗";
  font-size: 18px;
  transition: transform 0.3s ease;
}
.source-list a:hover::before {
  transform: scale(1.2);
}

/* Charts */
.chart-container { 
  position: relative; 
  width: 100%; 
  height: 50vh; 
  min-height: 300px; 
  max-height: 600px; 
  margin-top: 24px; 
  background: #F8FAFC;
  border: 2px solid #E2E8F0;
  border-radius: 16px;
  padding: 20px;
  box-shadow: 0 4px 16px rgba(0,0,0,0.05);
}
#comparisonChart { 
  width: 100% !important; 
  height: 100% !important; 
}

/* Bottom navigation */
.bottom-nav {
  position: fixed; 
  left: 0; 
  right: 0; 
  bottom: 0; 
  z-index: 1000;
  background: rgba(17,24,39,0.95); 
  backdrop-filter: blur(20px);
  border-top: 2px solid rgba(255,255,255,0.08);
  display: flex; 
  justify-content: space-around; 
  padding: 12px 8px;
  box-shadow: 0 -4px 16px rgba(0,0,0,0.1);
  height: 84px;
}
.nav-item { 
  display: flex; 
  flex-direction: column; 
  align-items: center; 
  color: #E5E7EB; 
  text-decoration: none; 
  padding: 12px 16px; 
  border-radius: 16px; 
  min-width: 72px; 
  transition: all 0.3s ease;
  position: relative;
  overflow: hidden;
}
.nav-item:hover { 
  background: rgba(255,255,255,0.08); 
  transform: translateY(-2px);
}
.nav-item.active { 
  background: linear-gradient(135deg, rgba(37,99,235,0.2), rgba(37,99,235,0.1)); 
  color: #FFF; 
  box-shadow: 0 4px 16px rgba(37,99,235,0.2);
}
.nav-item i { 
  font-size: 20px; 
  margin-bottom: 4px; 
  transition: transform 0.3s ease;
}
.nav-item:hover i {
  transform: scale(1.1);
}
.nav-item span { 
  font-size: 12px; 
  font-weight: 600; 
  letter-spacing: 0.5px;
}

footer { 
  background: transparent; 
  color: #94A3B8; 
  text-align: center; 
  padding: 5px 0 170px 0px; 
  font-size: 14px; 
  margin-top: 32px; 
  border-top: 1px solid rgba(255,255,255,0.06);
  font-weight: 500;
}
.footer-content {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 16px;
}
.footer-links {
  display: flex;
  gap: 20px;
  justify-content: center;
  flex-wrap: wrap;
}
.footer-link {
  display: flex;
  align-items: center;
  gap: 8px;
  color: #60A5FA;
  text-decoration: none;
  font-weight: 600;
  font-size: 14px;
  padding: 8px 16px;
  border-radius: 8px;
  transition: all 0.3s ease;
  background: rgba(96,165,250,0.1);
  border: 1px solid rgba(96,165,250,0.2);
}
.footer-link:hover {
  background: rgba(96,165,250,0.2);
  color: #3B82F6;
  transform: translateY(-2px);
  box-shadow: 0 4px 12px rgba(96,165,250,0.2);
}

.site-link {
  color: inherit;
  text-decoration: none;
  font-weight: inherit;
  transition: all 0.3s ease;
  border-bottom: 1px solid transparent;
  cursor: pointer;
}

.site-link:hover {
  color: #3B82F6;
  border-bottom-color: #3B82F6;
  text-decoration: none;
}

/* Seções - regras já definidas acima */

/* Configuração */
.config-container {
  margin-top: 20px;
}

/* Config feedback */
.config-feedback {
  margin: 20px 0;
  padding: 16px 20px;
  border-radius: 12px;
  border: 2px solid;
  position: relative;
  overflow: hidden;
  animation: slideInFromTop 0.4s ease-out;
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.1);
}

.config-feedback-success {
  background: linear-gradient(135deg, #F0FDF4, #DCFCE7);
  border-color: #16A34A;
  color: #15803D;
}

.config-feedback-info {
  background: linear-gradient(135deg, #F0F9FF, #DBEAFE);
  border-color: #3B82F6;
  color: #1D4ED8;
}

.config-feedback-warning {
  background: linear-gradient(135deg, #FFFBEB, #FEF3C7);
  border-color: #F59E0B;
  color: #D97706;
}

.config-feedback::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: linear-gradient(90deg, currentColor, rgba(255,255,255,0.3));
}

.feedback-content {
  display: flex;
  align-items: center;
  gap: 12px;
  font-weight: 600;
  font-size: 16px;
}

.feedback-content i {
  font-size: 20px;
  flex-shrink: 0;
}

@keyframes slideInFromTop {
  from {
    opacity: 0;
    transform: translateY(-20px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.config-section {
  background: linear-gradient(135deg, #F8FAFC, #F1F5F9);
  border: 2px solid #E2E8F0;
  border-radius: 16px;
  padding: 24px;
  margin-bottom: 24px;
  position: relative;
  overflow: hidden;
}

.config-section::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: linear-gradient(90deg, #3B82F6, #60A5FA, #10B981);
}

.config-section h3 {
  color: #1E293B;
  font-size: 20px;
  font-weight: 700;
  margin: 0 0 20px;
  display: flex;
  align-items: center;
  gap: 10px;
}

.config-section h3::before {
  font-size: 22px;
}

.config-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 20px;
  margin-bottom: 20px;
}

.config-item {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.config-item label {
  color: #374151;
  font-weight: 600;
  font-size: 14px;
  display: flex;
  align-items: center;
  gap: 6px;
}

.config-item input {
  padding: 12px 16px;
  border: 2px solid #E5E7EB;
  border-radius: 8px;
  font-size: 16px;
  font-weight: 500;
  background: white;
  transition: all 0.3s ease;
  color: #1F2937;
}

.config-item input:focus {
  outline: none;
  border-color: #3B82F6;
  box-shadow: 0 0 0 3px rgba(59, 130, 246, 0.1);
  transform: translateY(-1px);
}

.config-item input:hover {
  border-color: #9CA3AF;
}

.config-actions {
  display: flex;
  gap: 16px;
  justify-content: center;
  flex-wrap: wrap;
  margin: 30px 0;
  padding: 20px;
  background: linear-gradient(135deg, #F0F9FF, #E0F2FE);
  border-radius: 12px;
  border: 2px solid #BAE6FD;
}

.config-actions .btn {
  min-width: 160px;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  font-weight: 600;
  transition: all 0.3s ease;
}

.config-actions .btn:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 25px rgba(0, 0, 0, 0.15);
}

.config-info {
  margin-top: 30px;
}

.info-box {
  background: linear-gradient(135deg, #FEF3C7, #FDE68A);
  border: 2px solid #F59E0B;
  border-radius: 12px;
  padding: 20px;
  position: relative;
  overflow: hidden;
}

.info-box::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: linear-gradient(90deg, #F59E0B, #FBBF24, #FCD34D);
}

.info-box h4 {
  color: #92400E;
  font-size: 18px;
  font-weight: 700;
  margin: 0 0 12px;
  display: flex;
  align-items: center;
  gap: 8px;
}

.info-box h4::before {
  font-size: 20px;
}

.info-box ul {
  margin: 0;
  padding-left: 20px;
  color: #92400E;
  font-weight: 500;
}

.info-box li {
  margin-bottom: 8px;
  line-height: 1.5;
}
.footer-link i {
  font-size: 16px;
}

/* Responsive */
@media (min-width: 1200px) {
  .container { max-width: 1000px; }
  .app-main { max-width: 1400px; }
}

@media (min-width: 900px) {
  .results-grid { 
    grid-template-columns: 1fr 1fr; 
    gap: 16px;
  }
  .comparison-grid { 
    grid-template-columns: 1fr 1fr; 
    gap: 24px;
  }
  .radio-group {
    grid-template-columns: 1fr 1fr;
  }
  .chart-container {
    height: 60vh;
    min-height: 400px;
  }
}

@media (max-width: 768px) {
  .app-header { 
    padding: 16px 20px; 
  }
  .app-header h1 { 
    font-size: 22px; 
    gap: 10px;
  }
  .header-logo {
    height: 28px;
  }
  .deadline-alert {
    font-size: 14px;
    padding: 10px 16px;
    width: auto;
    max-width: fit-content;
  }
  .card { 
    padding: 20px; 
    margin-bottom: 16px;
  }
  .result-item { 
    grid-template-columns: 1fr; 
    gap: 12px;
    text-align: center;
  }
  .result-value {
    text-align: center;
  }
  .chart-container { 
    height: 40vh; 
    min-height: 250px; 
    padding: 16px;
  }
  .radio-group {
    grid-template-columns: 1fr;
  }
  .tax-model-selector {
    padding: 20px;
    margin: 20px 0;
  }
  .tax-model-selector h3 {
    font-size: 18px;
  }
  .radio-label {
    padding: 16px 20px;
  }
  .history-item {
    padding: 16px;
  }
  .comparison-item {
    padding: 20px;
  }
  .source-list li {
    padding: 16px;
  }
  .nav-item {
    min-width: 60px;
    padding: 10px 12px;
  }
  .nav-item i {
    font-size: 18px;
  }
  .nav-item span {
    font-size: 11px;
  }
}

@media (max-width: 480px) {
  .app-main { 
    padding: 16px 12px; 
  }
  .card { 
    padding: 16px; 
    margin-bottom: 12px;
  }
  .form-group input, .form-group select { 
    padding: 12px 14px; 
    font-size: 16px; 
  }
  .btn-primary, .btn-secondary, .btn-danger { 
    padding: 14px 20px; 
    font-size: 15px; 
    min-height: 48px;
  }
  .chart-container { 
    height: 35vh; 
    min-height: 200px; 
    padding: 12px;
  }
  .app-header {
    padding: 12px 16px;
  }
  .app-header h1 {
    font-size: 20px;
    gap: 8px;
  }
  .header-logo {
    height: 24px;
  }
  .deadline-alert {
    font-size: 13px;
    padding: 8px 14px;
    margin-top: 8px;
    width: auto;
    max-width: fit-content;
  }
  .important-notice {
    padding: 16px 20px;
    font-size: 15px;
    margin-bottom: 20px;
  }
  .tax-model-selector {
    padding: 16px;
    margin: 16px 0;
  }
  .tax-model-selector h3 {
    font-size: 16px;
  }
  .radio-label {
    padding: 14px 16px;
    gap: 10px;
  }
  .history-item {
    padding: 14px;
  }
  .comparison-item {
    padding: 16px;
  }
  .source-list li {
    padding: 14px;
  }
  .form-group input, .form-group select {
    padding: 14px 16px;
    font-size: 16px;
  }
  .nav-item {
    min-width: 50px;
    padding: 8px 10px;
  }
  .nav-item i {
    font-size: 16px;
  }
  .nav-item span {
    font-size: 10px;
  }
  .bottom-nav {
    padding: 8px 4px;
  }
  .footer-links {
    gap: 12px;
  }
  .footer-link {
    font-size: 13px;
    padding: 6px 12px;
  }
  
  .config-grid {
    grid-template-columns: 1fr;
    gap: 16px;
  }
  
  .config-actions {
    flex-direction: column;
    align-items: center;
  }
  
  .config-actions .btn {
    min-width: 200px;
    width: 100%;
  }
  
  .savings-analysis {
    flex-direction: column;
    gap: 12px;
  }
  
  .savings-positive,
  .savings-negative,
  .savings-neutral {
    min-width: auto;
    width: 100%;
  }
  
  .config-feedback {
    margin: 16px 0;
    padding: 12px 16px;
  }
  
  .feedback-content {
    font-size: 14px;
    gap: 8px;
  }
  
  .feedback-content i {
    font-size: 18px;
  }
  
  .header-logo {
    height: 20px;
  }
}