/* ============================================================
   CSS Custom Properties
   ============================================================ */
:root {
  /* Color Palette - Eco-friendly */
  --primary: #10b981;
  --secondary: #059669;
  --accent: #34d399;
  --danger: #ef4444;
  --warning: #f59e0b;
  --info: #3b82f6;

  /* Text & Background */
  --text: #1f2937;
  --text-light: #6b7280;
  --bg: #f9fafb;
  --white: #ffffff;

  /* Spacing Scale */
  --spacing-xs: 0.5rem;
  --spacing-sm: 0.75rem;
  --spacing-md: 1rem;
  --spacing-lg: 1.5rem;
  --spacing-xl: 2rem;
  --spacing-2xl: 2.5rem;
  --spacing-3xl: 3rem;

  /* Border Radius */
  --radius: 0.5rem;
  --radius-lg: 1rem;

  /* Shadows */
  --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
  --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
}

/* ============================================================
   Base Styles
   ============================================================ */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  background: linear-gradient(135deg, #d4fc79 0%, #96e6a1 100%);
  min-height: 100vh;
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen,
    Ubuntu, Cantarell, 'Fira Sans', 'Droid Sans', sans-serif;
  color: var(--text);
  line-height: 1.6;
}

.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: var(--spacing-lg);
}

/* ============================================================
   Utility Classes
   ============================================================ */
.hidden {
  display: none !important;
}

.visually-hidden {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border-width: 0;
}

.section-title {
  font-size: 1.875rem;
  font-weight: 700;
  color: var(--text);
  margin-bottom: var(--spacing-xl);
}

/* ============================================================
   Header Styles
   ============================================================ */
.site-header {
  background-color: var(--white);
  box-shadow: var(--shadow-md);
  padding: var(--spacing-xl);
  margin-bottom: var(--spacing-2xl);
}

.site-header__inner {
  max-width: 1200px;
  margin: 0 auto;
}

.site-header__title {
  font-size: 2rem;
  font-weight: 700;
  color: var(--primary);
  margin-bottom: var(--spacing-sm);
}

.site-header__subtitle {
  font-size: 1rem;
  color: var(--text-light);
}

/* ============================================================
   Main Layout
   ============================================================ */
.main {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 var(--spacing-lg);
}

/* ============================================================
   Calculator Form Styles
   ============================================================ */
.calculator {
  background-color: var(--white);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-lg);
  padding: var(--spacing-2xl);
  margin-bottom: var(--spacing-2xl);
}

.calculator__form {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-xl);
}

.calculator__row {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-md);
}

.calculator__row--inputs {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--spacing-md);
}

.calculator__row--distance {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--spacing-md);
}

.calculator__row--actions {
  margin-top: var(--spacing-xl);
}

.calculator__label {
  font-weight: 600;
  display: block;
  margin-bottom: var(--spacing-sm);
  color: var(--text);
}

.calculator__label--inline {
  display: inline;
  margin-bottom: 0;
  margin-left: var(--spacing-sm);
}

.calculator__input {
  width: 100%;
  padding: var(--spacing-md);
  border: 1px solid #d1d5db;
  border-radius: var(--radius);
  font-size: 1rem;
  font-family: inherit;
  transition: all 0.3s ease;
}

.calculator__input:focus {
  outline: none;
  border-color: var(--primary);
  box-shadow: 0 0 0 3px rgba(16, 185, 129, 0.1);
}

.calculator__input:disabled,
.calculator__input[readonly] {
  background-color: #f3f4f6;
  color: var(--text-light);
  cursor: not-allowed;
}

.calculator__helper {
  font-size: 0.875rem;
  color: var(--text-light);
  margin-top: var(--spacing-sm);
}

.calculator__fieldset {
  border: none;
  padding: 0;
}

.calculator__legend {
  font-size: 1.125rem;
  font-weight: 600;
  color: var(--text);
  margin-bottom: var(--spacing-lg);
  display: block;
}

/* ============================================================
   Transport Mode Grid
   ============================================================ */
.calculator__transport-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: var(--spacing-md);
}

@media (min-width: 768px) {
  .calculator__transport-grid {
    grid-template-columns: repeat(4, 1fr);
  }
}

.calculator__transport-item {
  position: relative;
  cursor: pointer;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  padding: var(--spacing-lg);
  border: 2px solid #e5e7eb;
  border-radius: var(--radius);
  background-color: var(--white);
  transition: all 0.3s ease;
  text-align: center;
}

.calculator__transport-item:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
  border-color: var(--primary);
}

.calculator__transport-item:has(> .calculator__transport-input:checked) {
  border-color: var(--primary);
  border-width: 2px;
  background-color: rgba(16, 185, 129, 0.15);
  box-shadow: 0 0 0 3px rgba(16, 185, 129, 0.1);
  font-weight: 600;
}

.calculator__transport-item:has(> .calculator__transport-input:checked) .calculator__transport-icon {
  font-size: 3.5rem;
  transform: scale(1.1);
}

.calculator__transport-item:has(> .calculator__transport-input:checked)::after {
  content: "✓";
  position: absolute;
  top: 8px;
  right: 8px;
  background-color: var(--primary);
  color: var(--white);
  width: 24px;
  height: 24px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  font-size: 0.875rem;
}

.calculator__transport-input {
  appearance: none;
  -webkit-appearance: none;
  -moz-appearance: none;
  width: 0;
  height: 0;
  opacity: 0;
  cursor: pointer;
}

/* Classe alternativa para feedback visual via JavaScript */
.calculator__transport-item.transport-selected {
  border-color: var(--primary);
  border-width: 2px;
  background-color: rgba(16, 185, 129, 0.15);
  box-shadow: 0 0 0 3px rgba(16, 185, 129, 0.1);
  font-weight: 600;
}

.calculator__transport-item.transport-selected .calculator__transport-icon {
  font-size: 3.5rem;
  transform: scale(1.1);
}
  align-items: center;
  justify-content: center;
  font-weight: 700;
  font-size: 0.875rem;
}

.calculator__transport-icon {
  font-size: 3rem;
  margin-bottom: var(--spacing-sm);
  display: block;
  transition: font-size 0.3s ease, transform 0.3s ease;
}

.calculator__transport-text {
  font-weight: 600;
  color: var(--text);
}

/* ============================================================
   Checkbox Styles
   ============================================================ */
.calculator__manual {
  display: flex;
  align-items: center;
  margin-top: var(--spacing-md);
}

.calculator__checkbox {
  width: 1.25rem;
  height: 1.25rem;
  cursor: pointer;
  accent-color: var(--primary);
}

/* ============================================================
   Button Styles
   ============================================================ */
.calculator__btn {
  width: 100%;
  padding: var(--spacing-md) var(--spacing-lg);
  background-color: var(--primary);
  color: var(--white);
  border: none;
  border-radius: var(--radius);
  font-size: 1rem;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.3s ease;
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.calculator__btn:hover {
  background-color: var(--secondary);
  transform: translateY(-2px);
  box-shadow: var(--shadow-lg);
}

.calculator__btn:active {
  transform: translateY(0);
}

.calculator__btn:disabled {
  background-color: #d1d5db;
  cursor: not-allowed;
  transform: none;
}

/* ============================================================
   Results Sections
   ============================================================ */
.results,
.comparison,
.carbon-credits {
  background-color: var(--white);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-lg);
  padding: var(--spacing-2xl);
  margin-bottom: var(--spacing-2xl);
}

.results__content,
.comparison__content,
.carbon-credits__content {
  min-height: 150px;
}

/* ============================================================
   Footer Styles
   ============================================================ */
.site-footer {
  background-color: var(--white);
  box-shadow: var(--shadow-md);
  padding: var(--spacing-xl);
  margin-top: var(--spacing-2xl);
}

.site-footer__inner {
  max-width: 1200px;
  margin: 0 auto;
}

.site-footer__credits {
  font-size: 0.875rem;
  color: var(--text-light);
  text-align: center;
}

/* ============================================================
   Spinner Animation
   ============================================================ */
.spinner {
  display: inline-block;
  width: 40px;
  height: 40px;
  border: 4px solid rgba(16, 185, 129, 0.2);
  border-top-color: var(--primary);
  border-radius: 50%;
  animation: spin 1s linear infinite;
}

@keyframes spin {
  to {
    transform: rotate(360deg);
  }
}

/* ============================================================
   Results Section Styles
   ============================================================ */
.results_card {
  background-color: var(--white);
  padding: var(--spacing-lg);
  margin-bottom: var(--spacing-lg);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-md);
  display: flex;
  align-items: center;
  animation: fadeIn 0.5s ease-out;
}

.results_icon {
  font-size: 2.5rem;
  margin-right: var(--spacing-lg);
  flex-shrink: 0;
}

.results_data {
  display: flex;
  flex-direction: column;
  flex: 1;
}

.results_label {
  font-size: 0.875rem;
  color: var(--text-light);
  text-transform: uppercase;
  letter-spacing: 0.05em;
  margin-bottom: var(--spacing-xs);
}

.results_value {
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--text);
}

.results_savings {
  border-left: 4px solid var(--accent);
  background-color: rgba(52, 211, 153, 0.1);
  padding: var(--spacing-lg);
  margin-top: var(--spacing-lg);
  display: flex;
  align-items: flex-start;
  gap: var(--spacing-lg);
}

.results_savings_icon {
  font-size: 2rem;
  flex-shrink: 0;
}

.results_savings_content {
  flex: 1;
}

.results_savings_label {
  font-size: 0.875rem;
  color: var(--text-light);
  text-transform: uppercase;
  letter-spacing: 0.05em;
  margin-bottom: var(--spacing-xs);
}

.results_savings_value {
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--text);
}

/* ============================================================
   Comparison Section Styles
   ============================================================ */
.comparison_item {
  padding: var(--spacing-md);
  margin-bottom: var(--spacing-md);
  border: 2px solid #e5e7eb;
  border-radius: var(--radius);
  transition: all 0.3s ease;
  cursor: pointer;
}

.comparison_item:hover {
  border-color: var(--primary);
  background-color: rgba(16, 185, 129, 0.05);
}

.comparison_item--selected {
  border-color: var(--primary);
  background-color: rgba(16, 185, 129, 0.1);
}

.comparison_header {
  display: flex;
  align-items: center;
  margin-bottom: var(--spacing-md);
  justify-content: space-between;
}

.comparison_mode {
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
}

.comparison_icon {
  font-size: 1.5rem;
}

.comparison_label {
  font-weight: 600;
  color: var(--text);
}

.comparison_badge {
  height: 24px;
  background-color: var(--primary);
  color: var(--white);
  padding: 0.25rem 0.5rem;
  border-radius: 12px;
  font-size: 0.75rem;
  font-weight: 600;
  display: inline-flex;
  align-items: center;
}

.comparison_stats {
  text-align: right;
  margin-bottom: var(--spacing-md);
}

.comparison_emission {
  font-weight: 700;
  font-size: 1.125rem;
  color: var(--text);
}

.comparison_percentage {
  font-size: 0.875rem;
  color: var(--text-light);
}

.comparison_bar-container {
  width: 100%;
  height: 12px;
  background-color: #e5e7eb;
  border-radius: var(--radius);
  overflow: hidden;
  margin-bottom: var(--spacing-md);
}

.comparison_bar {
  height: 100%;
  background: linear-gradient(90deg, var(--primary), var(--accent));
  border-radius: var(--radius);
  transition: width 0.5s ease;
}

.comparison_tip {
  background-color: rgba(59, 130, 246, 0.1);
  border-left: 4px solid var(--info);
  padding: var(--spacing-md);
  margin-top: var(--spacing-md);
  display: flex;
  gap: var(--spacing-md);
  border-radius: var(--radius);
}

.comparison_tip_icon {
  font-size: 1.25rem;
  flex-shrink: 0;
  color: var(--info);
}

.comparison_tip_text {
  font-size: 0.875rem;
  color: var(--text);
  line-height: 1.5;
}

/* ============================================================
   Carbon Credits Section Styles
   ============================================================ */
.carbon-credits_grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: var(--spacing-lg);
  margin-bottom: var(--spacing-lg);
}

.carbon-credits_card {
  background-color: var(--white);
  padding: var(--spacing-lg);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-md);
  animation: fadeIn 0.5s ease-out;
}

.carbon-credits_label {
  font-size: 0.875rem;
  color: var(--text-light);
  margin-bottom: var(--spacing-sm);
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.carbon-credits_value {
  font-size: 2.5rem;
  font-weight: 700;
  color: var(--primary);
}

.carbon-credits_hint {
  font-size: 0.75rem;
  color: var(--text-light);
  margin-top: var(--spacing-sm);
}

.carbon-credits_info {
  border: 2px dashed var(--info);
  background-color: rgba(59, 130, 246, 0.05);
  padding: var(--spacing-md);
  border-radius: var(--radius);
  margin-bottom: var(--spacing-lg);
}

.carbon-credits_info strong {
  font-weight: 700;
  color: var(--info);
}

.carbon-credits_info p {
  line-height: 1.6;
  color: var(--text);
  margin: var(--spacing-sm) 0;
}

.carbon-credits_info p:first-child {
  margin-top: 0;
}

.carbon-credits_btn {
  width: 100%;
  background-color: var(--primary);
  color: var(--white);
  padding: var(--spacing-md);
  border-radius: var(--radius);
  font-weight: 600;
  cursor: pointer;
  border: none;
  font-size: 1rem;
  transition: all 0.3s ease;
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.carbon-credits_btn:hover {
  background-color: var(--secondary);
  transform: translateY(-2px);
  box-shadow: var(--shadow-lg);
}

.carbon-credits_btn:active {
  transform: translateY(0);
}

/* ============================================================
   Animations
   ============================================================ */
@keyframes fadeIn {
  from {
    opacity: 0;
    transform: translateY(20px);
  }
  to {
    opacity: 1;
    transform: translateY(0px);
  }
}

.results_card,
.carbon-credits_card,
.comparison_item {
  animation: fadeIn 0.5s ease-out;
}

/* ============================================================
   Responsive Design
   ============================================================ */
@media (max-width: 767px) {
  .site-header__title {
    font-size: 1.5rem;
  }

  .calculator {
    padding: var(--spacing-lg);
  }

  .calculator__transport-grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .calculator__row--inputs {
    grid-template-columns: 1fr;
  }

  /* Results Mobile */
  .results_card {
    flex-direction: column;
    align-items: flex-start;
  }

  .results_icon {
    margin-right: 0;
    margin-bottom: var(--spacing-md);
  }

  .results_value {
    font-size: 1.25rem;
  }

  /* Carbon Credits Mobile */
  .carbon-credits_grid {
    grid-template-columns: 1fr;
  }

  /* Comparison Mobile */
  .comparison_header {
    flex-direction: column;
    align-items: flex-start;
  }

  .comparison_stats {
    text-align: left;
    width: 100%;
    margin-bottom: var(--spacing-md);
  }
}

@media (min-width: 768px) {
  .calculator__row--inputs {
    grid-template-columns: repeat(2, 1fr);
    gap: var(--spacing-lg);
  }

  .calculator__row--distance {
    grid-template-columns: 1fr;
  }

  .carbon-credits_grid {
    grid-template-columns: repeat(2, 1fr);
  }
}