/* CSS Variables for Theme Management */
:root {
  --color-primary: #00ADB5;
  --color-secondary: #393E46;
  --color-dark: #222831;
  --color-light: #EEEEEE;
  --color-accent: #FFD369;
  
  --bg-primary: var(--color-light);
  --bg-secondary: #FFFFFF;
  --bg-tertiary: #F8F9FA;
  --text-primary: var(--color-dark);
  --text-secondary: var(--color-secondary);
  --text-muted: #6C757D;
  --border-color: #DEE2E6;
  --shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
  --shadow-hover: 0 4px 20px rgba(0, 0, 0, 0.15);
  
  --border-radius: 8px;
  --border-radius-large: 12px;
  --transition: all 0.3s ease;
  --font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
}

/* Dark Theme Variables */
[data-theme="dark"] {
  --bg-primary: var(--color-dark);
  --bg-secondary: var(--color-secondary);
  --bg-tertiary: #2A2F38;
  --text-primary: var(--color-light);
  --text-secondary: #B8BCC8;
  --text-muted: #8E9297;
  --border-color: #404854;
  --shadow: 0 2px 10px rgba(0, 0, 0, 0.3);
  --shadow-hover: 0 4px 20px rgba(0, 0, 0, 0.4);
}

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

html {
  scroll-behavior: smooth;
}

body {
  font-family: var(--font-family);
  background-color: var(--bg-primary);
  color: var(--text-primary);
  line-height: 1.6;
  transition: var(--transition);
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

/* Container */
.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 1rem;
}

/* Header */
.header {
  background-color: var(--bg-secondary);
  box-shadow: var(--shadow);
  position: sticky;
  top: 0;
  z-index: 100;
}

.header .container {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 1rem;
}

.header__title {
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--color-primary);
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.header__icon {
  font-size: 1.8rem;
}

/* Theme Toggle */
.theme-toggle {
  background: var(--color-primary);
  border: none;
  border-radius: 50%;
  width: 3rem;
  height: 3rem;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  transition: var(--transition);
  box-shadow: var(--shadow);
}

.theme-toggle:hover {
  transform: scale(1.1);
  box-shadow: var(--shadow-hover);
}

.theme-toggle__icon {
  font-size: 1.2rem;
  color: white;
}

/* Main Content */
.main {
  flex: 1;
  padding: 2rem 0;
}

.header__icon {
  width: 60px;
  padding: 8px;
  border-radius: 12px;
  background-color: rgba(255, 255, 255, 0.05); /* fundo levemente translúcido */
  border: 1px solid rgba(255, 255, 255, 0.1);
  backdrop-filter: blur(4px);
  transition: transform 0.3s ease;
}

.header__icon:hover {
  transform: rotate(3deg) scale(1.05);
}

/* Tabs Navigation */
.tabs {
  display: flex;
  justify-content: center;
  gap: 0.5rem;
  margin-bottom: 2rem;
  overflow-x: auto;
  padding-bottom: 0.5rem;
  justify-content: flex-start;
 

}

.tabs__tab {
  background: var(--bg-secondary);
  border: 2px solid var(--border-color);
  border-radius: var(--border-radius);
  padding: 0.75rem 1rem;
  cursor: pointer;
  transition: var(--transition);
  white-space: nowrap;
  font-weight: 500;
  color: var(--text-secondary);
  min-width: fit-content;
  text-align: center;
}

.tabs__tab:hover {
  border-color: var(--color-primary);
  transform: translateY(-2px);
}

.tabs__tab--active {
  background: var(--color-primary);
  border-color: var(--color-primary);
  color: white;
  box-shadow: var(--shadow);
}

/* Converter Section */
.converter {
  background: var(--bg-secondary);
  border-radius: var(--border-radius-large);
  padding: 2rem;
  margin-bottom: 2rem;
  box-shadow: var(--shadow);
}

.converter__title {
  font-size: 1.5rem;
  margin-bottom: 1.5rem;
  color: var(--text-primary);
  text-align: center;
}

.converter__input-group {
  display: grid;
  grid-template-columns: 2fr 1fr;
  gap: 1rem;
  margin-bottom: 2rem;
}

/* Form Fields */
.input-field,
.select-field {
  display: flex;
  flex-direction: column;
}

.input-field__label,
.select-field__label {
  font-weight: 600;
  margin-bottom: 0.5rem;
  color: var(--text-secondary);
}

.input-field__input,
.select-field__select {
  padding: 0.75rem;
  border: 2px solid var(--border-color);
  border-radius: var(--border-radius);
  background: var(--bg-tertiary);
  color: var(--text-primary);
  font-size: 1rem;
  transition: var(--transition);
}

.input-field__input:focus,
.select-field__select:focus {
  outline: none;
  border-color: var(--color-primary);
  box-shadow: 0 0 0 3px rgba(0, 173, 181, 0.1);
}

/* Results Grid */
.converter__results {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: 1rem;
  margin-bottom: 2rem;
}

.result-card {
  background: var(--bg-tertiary);
  border: 2px solid var(--border-color);
  border-radius: var(--border-radius);
  padding: 1rem;
  transition: var(--transition);
}

.result-card:hover {
  border-color: var(--color-primary);
  transform: translateY(-2px);
  box-shadow: var(--shadow);
}

.result-card__unit {
  font-weight: 600;
  color: var(--color-primary);
  margin-bottom: 0.5rem;
}

.result-card__value {
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--text-primary);
  word-break: break-all;
}

/* Action Buttons */
.converter__actions {
  display: flex;
  gap: 1rem;
  justify-content: center;
}

.btn {
  padding: 0.75rem 1.5rem;
  border: none;
  border-radius: var(--border-radius);
  font-weight: 600;
  cursor: pointer;
  transition: var(--transition);
  text-decoration: none;
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  font-size: 1rem;
}

.btn--primary {
  background: var(--color-primary);
  color: white;
}

.btn--secondary {
  background: var(--bg-tertiary);
  color: var(--text-secondary);
  border: 2px solid var(--border-color);
}

.btn--small {
  padding: 0.5rem 1rem;
  font-size: 0.875rem;
}

.btn:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-hover);
}

.btn--primary:hover {
  background: #009AA1;
}

.btn--secondary:hover {
  border-color: var(--color-primary);
}

/* History Section */
.history {
  background: var(--bg-secondary);
  border-radius: var(--border-radius-large);
  padding: 2rem;
  margin-bottom: 2rem;
  box-shadow: var(--shadow);
}

.history__title {
  font-size: 1.25rem;
  margin-bottom: 1rem;
  color: var(--text-primary);
}

.history__controls {
  margin-bottom: 1rem;
}

.history__list {
  max-height: 300px;
  overflow-y: auto;
}

.history__item {
  background: var(--bg-tertiary);
  border-radius: var(--border-radius);
  padding: 1rem;
  margin-bottom: 0.5rem;
  border-left: 4px solid var(--color-primary);
}

.history__item-content {
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 0.5rem;
}

.history__item-conversion {
  font-weight: 600;
  color: var(--text-primary);
}

.history__item-time {
  font-size: 0.875rem;
  color: var(--text-muted);
}

/* Favorites Section */
.favorites {
  background: var(--bg-secondary);
  border-radius: var(--border-radius-large);
  padding: 2rem;
  margin-bottom: 2rem;
  box-shadow: var(--shadow);
}

.favorites__title {
  font-size: 1.25rem;
  margin-bottom: 1rem;
  color: var(--text-primary);
}

.favorites__list {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 1rem;
}

.favorite-card {
  background: var(--bg-tertiary);
  border: 2px solid var(--border-color);
  border-radius: var(--border-radius);
  padding: 1rem;
  transition: var(--transition);
  cursor: pointer;
}

.favorite-card:hover {
  border-color: var(--color-accent);
  transform: translateY(-2px);
}

.favorite-card__header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 0.5rem;
}

.favorite-card__category {
  font-size: 0.875rem;
  color: var(--color-primary);
  font-weight: 600;
}

.favorite-card__remove {
  background: none;
  border: none;
  color: var(--text-muted);
  cursor: pointer;
  padding: 0.25rem;
  border-radius: 50%;
  transition: var(--transition);
}

.favorite-card__remove:hover {
  background: #dc3545;
  color: white;
}

.favorite-card__conversion {
  font-weight: 600;
  color: var(--text-primary);
}

/* FAQ Section */
.faq {
  background: var(--bg-secondary);
  border-radius: var(--border-radius-large);
  padding: 2rem;
  margin-bottom: 2rem;
  box-shadow: var(--shadow);
}

.faq__title {
  font-size: 1.5rem;
  margin-bottom: 1.5rem;
  color: var(--text-primary);
  text-align: center;
}

.faq__item {
  border-bottom: 1px solid var(--border-color);
  margin-bottom: 1rem;
  padding-bottom: 1rem;
}

.faq__item:last-child {
  border-bottom: none;
  margin-bottom: 0;
}

.faq__question {
  font-size: 1.1rem;
  color: var(--color-primary);
  margin-bottom: 0.5rem;
  cursor: pointer;
  transition: var(--transition);
}

.faq__question:hover {
  color: var(--color-accent);
}

.faq__answer {
  color: var(--text-secondary);
  line-height: 1.6;
}

/* Footer */
.footer {
  background: var(--color-secondary);
  color: var(--color-light);
  text-align: center;
  padding: 1.5rem 0;
  margin-top: auto;
}

.footer__text {
  margin: 0;
}

.footer__link {
  color: var(--color-primary);
  text-decoration: none;
  font-weight: 600;
  transition: var(--transition);
}

.footer__link:hover {
  color: var(--color-accent);
}

/* PWA Install Banner */
.install-banner {
  position: fixed;
  bottom: 1rem;
  left: 1rem;
  right: 1rem;
  background: var(--color-primary);
  color: white;
  border-radius: var(--border-radius);
  box-shadow: var(--shadow-hover);
  z-index: 1000;
  animation: slideUp 0.3s ease;
}

.install-banner__content {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 1rem;
  gap: 1rem;
}

.install-banner__text {
  font-weight: 600;
}

.install-banner__btn {
  background: white;
  color: var(--color-primary);
  border: none;
  border-radius: var(--border-radius);
  padding: 0.5rem 1rem;
  font-weight: 600;
  cursor: pointer;
  transition: var(--transition);
}

.install-banner__btn:hover {
  transform: scale(1.05);
}

.install-banner__close {
  background: none;
  border: none;
  color: white;
  font-size: 1.2rem;
  cursor: pointer;
  padding: 0.25rem;
  border-radius: 50%;
  transition: var(--transition);
}

.install-banner__close:hover {
  background: rgba(255, 255, 255, 0.2);
}

/* Animations */
@keyframes slideUp {
  from {
    transform: translateY(100%);
    opacity: 0;
  }
  to {
    transform: translateY(0);
    opacity: 1;
  }
}

.fade-in {
  animation: fadeIn 0.3s ease;
}

@keyframes fadeIn {
  from {
    opacity: 0;
    transform: translateY(10px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

/* Responsive Design */
@media (max-width: 768px) {
  .container {
    padding: 0 0.75rem;
  }
  
  .header .container {
    padding: 0.75rem;
  }
  
  .header__title {
    font-size: 1.25rem;
  }
  
  .tabs {
    gap: 0.25rem;
  }
  
  .tabs__tab {
    padding: 0.5rem 0.75rem;
    font-size: 0.875rem;
  }
  
  .converter {
    padding: 1.5rem;
  }
  
  .converter__input-group {
    grid-template-columns: 1fr;
    gap: 1rem;
  }
  
  .converter__results {
    grid-template-columns: 1fr;
  }
  
  .converter__actions {
    flex-direction: column;
  }
  
  .btn {
    width: 100%;
    justify-content: center;
  }
  
  .history,
  .favorites,
  .faq {
    padding: 1.5rem;
  }
  
  .favorites__list {
    grid-template-columns: 1fr;
  }
  
  .history__item-content {
    flex-direction: column;
    align-items: flex-start;
  }
  
  .install-banner__content {
    flex-direction: column;
    text-align: center;
  }
}

@media (max-width: 480px) {
  .main {
    padding: 1rem 0;
  }
  
  .converter,
  .history,
  .favorites,
  .faq {
    padding: 1rem;
  }
  
  .faq__question {
    font-size: 1rem;
  }
  
  .result-card__value {
    font-size: 1.1rem;
  }
}

/* Print Styles */
@media print {
  .header,
  .theme-toggle,
  .converter__actions,
  .history__controls,
  .install-banner {
    display: none;
  }
  
  body {
    background: white;
    color: black;
  }
  
  .converter,
  .history,
  .favorites,
  .faq {
    box-shadow: none;
    border: 1px solid #ccc;
  }
}

/* High Contrast Mode */
@media (prefers-contrast: high) {
  :root {
    --shadow: 0 2px 10px rgba(0, 0, 0, 0.3);
    --shadow-hover: 0 4px 20px rgba(0, 0, 0, 0.4);
  }
  
  .tabs__tab,
  .result-card,
  .input-field__input,
  .select-field__select {
    border-width: 3px;
  }
}

/* Reduced Motion */
@media (prefers-reduced-motion: reduce) {
  * {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }
}

/* Focus Styles for Accessibility */
button:focus-visible,
input:focus-visible,
select:focus-visible {
  outline: 3px solid var(--color-accent);
  outline-offset: 2px;
}

/* Loading State */
.loading {
  opacity: 0.6;
  pointer-events: none;
}

.loading::after {
  content: '';
  position: absolute;
  top: 50%;
  left: 50%;
  width: 20px;
  height: 20px;
  margin: -10px 0 0 -10px;
  border: 2px solid var(--color-primary);
  border-radius: 50%;
  border-top-color: transparent;
  animation: spin 1s linear infinite;
}

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

/* Empty State */
.empty-state {
  text-align: center;
  padding: 2rem;
  color: var(--text-muted);
}

.empty-state__icon {
  font-size: 3rem;
  margin-bottom: 1rem;
  opacity: 0.5;
}

.empty-state__text {
  font-size: 1.1rem;
  margin-bottom: 0.5rem;
}

.empty-state__subtext {
  font-size: 0.9rem;
}