styles.css

/* Variables CSS para temas */
:root {
  --bg-primary: #0f1419;
  --bg-secondary: #1a1f2e;
  --bg-tertiary: #252b3a;
  --text-primary: #ffffff;
  --text-secondary: #b8c5d1;
  --text-muted: #8a9ba8;
  --accent-primary: #6c63ff;
  --accent-secondary: #a259f7;
  --accent-hover: #5a52d5;
  --border-color: #2d3748;
  --shadow-light: rgba(108, 99, 255, 0.1);
  --shadow-medium: rgba(0, 0, 0, 0.3);
  --shadow-heavy: rgba(0, 0, 0, 0.5);
  --gradient-primary: linear-gradient(135deg, var(--accent-primary), var(--accent-secondary));
  --gradient-bg: linear-gradient(135deg, var(--bg-primary), var(--bg-secondary));
  --border-radius: 12px;
  --border-radius-lg: 16px;
  --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

/* Temas */
.theme-light {
  --bg-primary: #ffffff;
  --bg-secondary: #f8fafc;
  --bg-tertiary: #e2e8f0;
  --text-primary: #1a202c;
  --text-secondary: #4a5568;
  --text-muted: #718096;
  --border-color: #e2e8f0;
  --shadow-light: rgba(108, 99, 255, 0.1);
  --shadow-medium: rgba(0, 0, 0, 0.1);
  --shadow-heavy: rgba(0, 0, 0, 0.2);
}

.theme-green {
  --bg-primary: #0d1b0f;
  --bg-secondary: #1a2e1d;
  --bg-tertiary: #2d4a32;
  --accent-primary: #10b981;
  --accent-secondary: #34d399;
  --accent-hover: #059669;
  --gradient-primary: linear-gradient(135deg, #10b981, #34d399);
}

.theme-purple {
  --bg-primary: #1a0d1f;
  --bg-secondary: #2d1b36;
  --bg-tertiary: #4a2d5a;
  --accent-primary: #8b5cf6;
  --accent-secondary: #a78bfa;
  --accent-hover: #7c3aed;
  --gradient-primary: linear-gradient(135deg, #8b5cf6, #a78bfa);
}

/* Reset y base */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
  background: var(--gradient-bg);
  color: var(--text-primary);
  line-height: 1.6;
  min-height: 100vh;
  overflow-x: hidden;
}

/* Pantalla de carga */
.loading-screen {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: var(--gradient-bg);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 9999;
  transition: opacity 0.5s ease, visibility 0.5s ease;
}

.loading-screen.hidden {
  opacity: 0;
  visibility: hidden;
}

.loading-container {
  text-align: center;
  max-width: 300px;
}

.unit-logo {
  margin-bottom: 2rem;
  animation: logoFloat 3s ease-in-out infinite;
}

.loading-title {
  font-size: 1.5rem;
  font-weight: 600;
  margin-bottom: 2rem;
  background: var(--gradient-primary);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.loading-spinner {
  width: 40px;
  height: 40px;
  border: 3px solid var(--border-color);
  border-top: 3px solid var(--accent-primary);
  border-radius: 50%;
  margin: 0 auto 1.5rem;
  animation: spin 1s linear infinite;
}

.loading-progress {
  width: 100%;
  height: 4px;
  background: var(--border-color);
  border-radius: 2px;
  overflow: hidden;
  margin-bottom: 1rem;
}

.progress-bar {
  height: 100%;
  background: var(--gradient-primary);
  border-radius: 2px;
  width: 0%;
  transition: width 0.3s ease;
}

.loading-text {
  color: var(--text-secondary);
  font-size: 0.9rem;
}

/* Animaciones */
@keyframes spin {
  0% { transform: rotate(0deg); }
  100% { transform: rotate(360deg); }
}

@keyframes logoFloat {
  0%, 100% { transform: translateY(0px); }
  50% { transform: translateY(-10px); }
}

@keyframes fadeInUp {
  from {
    opacity: 0;
    transform: translateY(30px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

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

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

@keyframes pulse {
  0%, 100% { transform: scale(1); }
  50% { transform: scale(1.05); }
}

/* Aplicación principal */
#app {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  transition: var(--transition);
}

.app-hidden {
  opacity: 0;
  visibility: hidden;
}

/* Header */
.header {
  background: var(--bg-secondary);
  border-bottom: 1px solid var(--border-color);
  backdrop-filter: blur(10px);
  position: sticky;
  top: 0;
  z-index: 100;
}

.header-content {
  max-width: 1200px;
  margin: 0 auto;
  padding: 1rem 2rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.logo-section {
  display: flex;
  align-items: center;
  gap: 1rem;
}

.app-logo {
  width: 40px;
  height: 40px;
  background: var(--gradient-primary);
  border-radius: var(--border-radius);
  display: flex;
  align-items: center;
  justify-content: center;
  color: white;
}

.app-title h1 {
  font-size: 1.5rem;
  font-weight: 700;
  margin: 0;
}

.app-subtitle {
  font-size: 0.8rem;
  color: var(--text-muted);
  font-weight: 400;
}

.header-controls {
  display: flex;
  gap: 0.5rem;
}

.theme-btn, .lang-btn {
  width: 40px;
  height: 40px;
  border: none;
  background: var(--bg-tertiary);
  color: var(--text-primary);
  border-radius: var(--border-radius);
  cursor: pointer;
  transition: var(--transition);
  display: flex;
  align-items: center;
  justify-content: center;
}

.theme-btn:hover, .lang-btn:hover {
  background: var(--accent-primary);
  transform: translateY(-2px);
}

/* Main content */
.main-content {
  flex: 1;
  padding: 2rem;
  max-width: 800px;
  margin: 0 auto;
  width: 100%;
}

.converter-card {
  background: var(--bg-secondary);
  border-radius: var(--border-radius-lg);
  padding: 2rem;
  box-shadow: 0 10px 40px var(--shadow-medium);
  border: 1px solid var(--border-color);
  animation: fadeInUp 0.6s ease;
}

.card-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 2rem;
  padding-bottom: 1rem;
  border-bottom: 1px solid var(--border-color);
}

.card-header h2 {
  font-size: 1.5rem;
  font-weight: 600;
}

.card-actions {
  display: flex;
  gap: 0.5rem;
}

.action-btn {
  width: 36px;
  height: 36px;
  border: none;
  background: var(--bg-tertiary);
  color: var(--text-secondary);
  border-radius: var(--border-radius);
  cursor: pointer;
  transition: var(--transition);
  display: flex;
  align-items: center;
  justify-content: center;
}

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

/* Formulario */
.converter-form {
  display: flex;
  flex-direction: column;
  gap: 1.5rem;
}

.form-group {
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}

.form-group label {
  font-weight: 500;
  color: var(--text-secondary);
  font-size: 0.9rem;
}

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

.form-select:focus, .form-input:focus {
  outline: none;
  border-color: var(--accent-primary);
  box-shadow: 0 0 0 3px var(--shadow-light);
}

.input-wrapper {
  position: relative;
}

.clear-btn {
  position: absolute;
  right: 0.5rem;
  top: 50%;
  transform: translateY(-50%);
  width: 24px;
  height: 24px;
  border: none;
  background: var(--text-muted);
  color: var(--bg-primary);
  border-radius: 50%;
  cursor: pointer;
  font-size: 0.8rem;
  transition: var(--transition);
}

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

.conversion-row {
  display: grid;
  grid-template-columns: 1fr auto 1fr;
  gap: 1rem;
  align-items: end;
}

.unit-group {
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}

.swap-btn {
  width: 48px;
  height: 48px;
  border: 2px solid var(--border-color);
  background: var(--bg-tertiary);
  color: var(--text-primary);
  border-radius: 50%;
  cursor: pointer;
  transition: var(--transition);
  display: flex;
  align-items: center;
  justify-content: center;
}

.swap-btn:hover {
  border-color: var(--accent-primary);
  background: var(--accent-primary);
  color: white;
  transform: rotate(180deg);
}

.convert-btn {
  padding: 1rem 2rem;
  border: none;
  background: var(--gradient-primary);
  color: white;
  border-radius: var(--border-radius);
  font-size: 1.1rem;
  font-weight: 600;
  cursor: pointer;
  transition: var(--transition);
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  margin-top: 1rem;
}

.convert-btn:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 25px var(--shadow-light);
}

.convert-btn:active {
  transform: translateY(0);
}

/* Resultado */
.result-section {
  margin-top: 2rem;
}

.result-card {
  background: var(--bg-tertiary);
  border-radius: var(--border-radius);
  padding: 1.5rem;
  border: 1px solid var(--border-color);
}

.result-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 1rem;
}

.result-header span {
  font-weight: 500;
  color: var(--text-secondary);
}

.copy-btn {
  width: 32px;
  height: 32px;
  border: none;
  background: transparent;
  color: var(--text-muted);
  cursor: pointer;
  border-radius: var(--border-radius);
  transition: var(--transition);
}

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

.result-value {
  font-size: 2rem;
  font-weight: 700;
  color: var(--accent-primary);
  margin-bottom: 0.5rem;
  word-break: break-all;
}

.result-formula {
  font-size: 0.9rem;
  color: var(--text-muted);
  font-style: italic;
}

/* Conversiones rápidas */
.quick-conversions {
  margin-top: 2rem;
  padding-top: 2rem;
  border-top: 1px solid var(--border-color);
}

.quick-conversions h3 {
  font-size: 1.2rem;
  margin-bottom: 1rem;
  color: var(--text-secondary);
}

.quick-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
  gap: 1rem;
}

.quick-item {
  background: var(--bg-tertiary);
  padding: 1rem;
  border-radius: var(--border-radius);
  text-align: center;
  cursor: pointer;
  transition: var(--transition);
  border: 1px solid var(--border-color);
}

.quick-item:hover {
  background: var(--accent-primary);
  color: white;
  transform: translateY(-2px);
}

.quick-value {
  font-size: 1.1rem;
  font-weight: 600;
  margin-bottom: 0.25rem;
}

.quick-unit {
  font-size: 0.8rem;
  color: var(--text-muted);
}

.quick-item:hover .quick-unit {
  color: rgba(255, 255, 255, 0.8);
}

/* Footer */
.footer {
  background: var(--bg-secondary);
  border-top: 1px solid var(--border-color);
  padding: 2rem;
  margin-top: auto;
}

.footer-content {
  max-width: 1200px;
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 1rem;
}

.footer-content p {
  color: var(--text-muted);
  font-size: 0.9rem;
}

.footer-links {
  display: flex;
  gap: 2rem;
}

.footer-link {
  background: none;
  border: none;
  color: var(--text-muted);
  text-decoration: none;
  font-size: 0.9rem;
  cursor: pointer;
  transition: var(--transition);
  padding: 0;
}

.footer-link:hover {
  color: var(--accent-primary);
}

/* Panel lateral */
.side-panel {
  position: fixed;
  top: 0;
  right: 0;
  width: 100%;
  height: 100%;
  z-index: 10000;
  pointer-events: none;
  transition: var(--transition);
}

.side-panel.active {
  pointer-events: auto;
}

.panel-overlay {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: rgba(0, 0, 0, 0.5);
  backdrop-filter: blur(4px);
  opacity: 0;
  transition: opacity 0.3s ease;
}

.side-panel.active .panel-overlay {
  opacity: 1;
}

.panel-content {
  position: absolute;
  top: 0;
  right: 0;
  width: min(450px, 90vw);
  height: 100%;
  background: var(--bg-secondary);
  box-shadow: -10px 0 40px var(--shadow-heavy);
  transform: translateX(100%);
  transition: transform 0.4s cubic-bezier(0.4, 0, 0.2, 1);
  display: flex;
  flex-direction: column;
  border-left: 1px solid var(--border-color);
}

.side-panel.active .panel-content {
  transform: translateX(0);
}

.panel-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 1.5rem 2rem;
  border-bottom: 1px solid var(--border-color);
  background: var(--bg-tertiary);
}

.panel-header h2 {
  font-size: 1.3rem;
  font-weight: 600;
  color: var(--text-primary);
}

.panel-close {
  width: 40px;
  height: 40px;
  border: none;
  background: transparent;
  color: var(--text-muted);
  cursor: pointer;
  border-radius: var(--border-radius);
  transition: var(--transition);
  display: flex;
  align-items: center;
  justify-content: center;
}

.panel-close:hover {
  background: var(--accent-primary);
  color: white;
}

.panel-body {
  flex: 1;
  padding: 2rem;
  overflow-y: auto;
  color: var(--text-primary);
  line-height: 1.7;
}

.panel-body h3 {
  color: var(--accent-primary);
  margin: 1.5rem 0 1rem 0;
  font-size: 1.1rem;
}

.panel-body p {
  margin-bottom: 1rem;
}

.panel-body ul {
  margin: 1rem 0;
  padding-left: 1.5rem;
}

.panel-body li {
  margin-bottom: 0.5rem;
}

.panel-body a {
  color: var(--accent-primary);
  text-decoration: none;
  transition: var(--transition);
}

.panel-body a:hover {
  color: var(--accent-secondary);
  text-decoration: underline;
}

.panel-body .feature-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 1rem;
  margin: 1.5rem 0;
}

.panel-body .feature-item {
  background: var(--bg-tertiary);
  padding: 1rem;
  border-radius: var(--border-radius);
  border: 1px solid var(--border-color);
}

.panel-body .feature-item h4 {
  color: var(--accent-primary);
  margin-bottom: 0.5rem;
  font-size: 0.9rem;
}

.panel-body .contact-info {
  background: var(--bg-tertiary);
  padding: 1.5rem;
  border-radius: var(--border-radius);
  border: 1px solid var(--border-color);
  margin: 1.5rem 0;
}

.panel-body .lang-selector {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  margin: 1rem 0;
}

.panel-body .lang-option {
  padding: 0.5rem 1rem;
  background: var(--bg-tertiary);
  border: 1px solid var(--border-color);
  border-radius: var(--border-radius);
  cursor: pointer;
  transition: var(--transition);
  font-size: 0.9rem;
}

.panel-body .lang-option:hover,
.panel-body .lang-option.active {
  background: var(--accent-primary);
  color: white;
  border-color: var(--accent-primary);
}

/* Responsive */
@media (max-width: 768px) {
  .header-content {
    padding: 1rem;
  }
  
  .main-content {
    padding: 1rem;
  }
  
  .converter-card {
    padding: 1.5rem;
  }
  
  .conversion-row {
    grid-template-columns: 1fr;
    gap: 1rem;
  }
  
  .swap-btn {
    order: 3;
    justify-self: center;
    transform: rotate(90deg);
  }
  
  .swap-btn:hover {
    transform: rotate(270deg);
  }
  
  .footer-content {
    flex-direction: column;
    text-align: center;
  }
  
  .quick-grid {
    grid-template-columns: repeat(auto-fit, minmax(120px, 1fr));
  }

  .panel-content {
    width: 100vw;
  }

  .panel-body {
    padding: 1.5rem;
  }
}

@media (max-width: 480px) {
  .loading-title {
    font-size: 1.2rem;
  }
  
  .app-title h1 {
    font-size: 1.2rem;
  }
  
  .result-value {
    font-size: 1.5rem;
  }

  .panel-header {
    padding: 1rem 1.5rem;
  }
}

/* Estados especiales */
.loading .convert-btn {
  opacity: 0.7;
  cursor: not-allowed;
}

.error .result-value {
  color: #ef4444;
}

.success .result-card {
  border-color: var(--accent-primary);
  box-shadow: 0 0 0 1px var(--shadow-light);
}

/* Animaciones adicionales */
.result-card.animate {
  animation: pulse 0.6s ease;
}

.quick-item.animate {
  animation: fadeInUp 0.4s ease;
}

/* Scrollbar personalizado para el panel */
.panel-body::-webkit-scrollbar {
  width: 6px;
}

.panel-body::-webkit-scrollbar-track {
  background: var(--bg-tertiary);
}

.panel-body::-webkit-scrollbar-thumb {
  background: var(--border-color);
  border-radius: 3px;
}

.panel-body::-webkit-scrollbar-thumb:hover {
  background: var(--accent-primary);
}