:root {
  --bg: #0f172a; /* used in gradient mix */
  --bg-2: #111827;
  --surface: #ffffff;
  --surface-contrast: #0b1220;
  --text: #1f2937;
  --muted: #6b7280;
  --primary: #2a4d7b;
  --primary-600: #1d3655;
  --primary-100: #d6e3f9;
  --ring: rgba(42, 77, 123, 0.35);
  --border: rgba(2,6,23,0.08);
  --shadow: 0 10px 30px rgba(2, 6, 23, 0.08);
}

@media (prefers-color-scheme: dark) {
  :root {
    --surface: #0b1220;
    --text: #e5e7eb;
    --muted: #9ca3af;
    --border: rgba(255,255,255,0.08);
    --shadow: 0 12px 40px rgba(0,0,0,0.45);
  }
}

* { box-sizing: border-box; }
html, body { height: 100%; }

body {
  font-family: 'Inter', system-ui, -apple-system, Segoe UI, Roboto, Helvetica, Arial, "Apple Color Emoji", "Segoe UI Emoji";
  background:
    radial-gradient(1200px 600px at 10% -10%, rgba(42,77,123,0.15), transparent 50%),
    radial-gradient(900px 500px at 100% 0%, rgba(16,185,129,0.08), transparent 40%),
    linear-gradient(180deg, #f8fafc 0%, #eef2f7 100%);
  color: var(--text);
  margin: 0;
}

@media (prefers-color-scheme: dark) {
  body {
    background:
      radial-gradient(1200px 600px at 0% -10%, rgba(42,77,123,0.20), transparent 50%),
      radial-gradient(900px 500px at 100% -10%, rgba(16,185,129,0.10), transparent 40%),
      linear-gradient(180deg, #0b1220 0%, #0b1220 100%);
  }
}

.container {
  max-width: 980px;
  margin: 40px auto;
  padding: 28px 22px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 16px;
  box-shadow: var(--shadow);
  backdrop-filter: saturate(140%) blur(6px);
}

@media (max-width: 640px) {
  .container { margin: 18px auto; padding: 18px 14px; border-radius: 14px; }
}

h1 {
  margin: 0 0 6px 0;
  text-align: center;
  color: var(--primary-600);
  font-size: 28px;
  letter-spacing: -0.01em;
}

.subtitle {
  margin: 0 0 20px 0;
  text-align: center;
  color: var(--muted);
  font-size: 14px;
}

.drop-area {
  position: relative;
  border: 2px dashed var(--primary);
  padding: 28px 18px;
  text-align: center;
  border-radius: 14px;
  transition: background 0.3s ease, border-color 0.3s ease, transform 0.2s ease, box-shadow 0.2s ease;
  background: rgba(255,255,255,0.9);
  margin-bottom: 16px;
}

@media (prefers-color-scheme: dark) {
  .drop-area { background: rgba(11,18,32,0.9); }
}

.drop-area.highlight {
  background: linear-gradient(0deg, rgba(42,77,123,0.06), rgba(42,77,123,0.06)), var(--surface);
  box-shadow: 0 0 0 6px var(--ring);
  transform: translateY(-1px);
}

.file-label {
  color: var(--primary-600);
  font-weight: 600;
  text-decoration: none;
  cursor: pointer;
  border-bottom: 1px dashed currentColor;
}
.file-label:hover { opacity: 0.9; }

/* Ocultar el input real y usar el label como activador accesible */
#fileElem { display: none; }

.actions {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 10px;
  margin-bottom: 16px;
}

@media (max-width: 520px) {
  .actions { grid-template-columns: 1fr; }
}

.options {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 10px;
  align-items: center;
  margin-bottom: 12px;
}

@media (max-width: 520px) {
  .options { grid-template-columns: 1fr; }
}

.option-item {
  display: flex;
  align-items: center;
  gap: 8px;
  color: var(--text);
}

.option-item select {
  padding: 6px 8px;
  border: 1px solid var(--border);
  border-radius: 8px;
  background: var(--surface);
  color: inherit;
}

@media (prefers-color-scheme: dark) {
  .option-item select { background: var(--surface); }
}

.preview-container {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
  gap: 14px;
}

@media (max-width: 520px) {
  .preview-container { grid-template-columns: repeat(auto-fit, minmax(120px, 1fr)); gap: 10px; }
}

.preview-item {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 12px;
  box-shadow: var(--shadow);
  padding: 8px 8px 12px 8px;
  text-align: center;
  transition: transform 0.18s ease, box-shadow 0.18s ease;
  position: relative;
}

.preview-item:hover { transform: translateY(-2px); }

.preview-item img {
  width: 100%;
  height: auto;
  border-radius: 8px;
  display: block;
}

.preview-meta {
  margin-top: 8px;
  display: flex;
  flex-direction: column;
  gap: 2px;
}

.file-name {
  font-size: 12px;
  font-weight: 600;
  color: var(--text);
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.file-pages {
  font-size: 11px;
  color: var(--muted);
}

.preview-item .remove-btn {
  position: absolute;
  top: 6px;
  right: 6px;
  width: 28px;
  height: 28px;
  border-radius: 999px;
  background: rgba(0,0,0,0.05);
  border: 1px solid var(--border);
  display: inline-flex;
  align-items: center;
  justify-content: center;
  color: var(--muted);
  cursor: pointer;
  transition: background 0.12s ease, color 0.12s ease;
}

.preview-item .remove-btn:hover { background: rgba(220, 38, 38, 0.08); color: #ef4444; }

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  margin: 16px auto 8px auto;
  padding: 12px 22px;
  background: linear-gradient(180deg, var(--primary) 0%, var(--primary-600) 100%);
  color: white;
  border: none;
  border-radius: 10px;
  cursor: pointer;
  font-size: 16px;
  font-weight: 600;
  letter-spacing: 0.01em;
  transition: transform 0.12s ease, filter 0.12s ease, box-shadow 0.12s ease;
  box-shadow: 0 8px 18px rgba(42,77,123,0.25);
}

.btn.secondary { background: linear-gradient(180deg, #2563eb 0%, #1d4ed8 100%); }
.btn.ghost {
  background: transparent;
  color: var(--primary-600);
  border: 1px solid var(--border);
  box-shadow: none;
}
.btn.ghost:hover { background: rgba(42,77,123,0.06); }

@media (max-width: 520px) {
  .btn { width: 100%; margin: 10px 0; }
}

.btn:disabled {
  background: linear-gradient(180deg, #9ca3af 0%, #6b7280 100%);
  cursor: not-allowed;
  box-shadow: none;
  opacity: 0.9;
}

.btn:hover:not(:disabled) { filter: brightness(1.02); transform: translateY(-1px); }

.btn:focus-visible {
  outline: none;
  box-shadow: 0 0 0 6px var(--ring);
}

.download-btn {
  text-align: center;
  text-decoration: none;
}

.status {
  text-align: center;
  font-size: 14px;
  margin-top: 10px;
  color: var(--muted);
}

.app-footer {
  margin-top: 20px;
  text-align: center;
  color: var(--muted);
  font-size: 13px;
}

.app-footer strong { color: var(--primary-600); }

.status.loading::before {
  content: "";
  width: 1em;
  height: 1em;
  border: 2px solid rgba(148,163,184,0.5);
  border-top-color: var(--primary-600);
  border-radius: 50%;
  display: inline-block;
  margin-right: 8px;
  animation: spin 0.8s linear infinite;
  vertical-align: -2px;
}

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

/* Nuevos estilos para indicadores de progreso y estados */
.progress-container {
  text-align: center;
  padding: 20px;
  background: rgba(42, 77, 123, 0.05);
  border-radius: 12px;
  border: 1px solid var(--border);
  margin: 16px 0;
}

.progress-stage {
  font-size: 16px;
  font-weight: 600;
  color: var(--primary-600);
  margin-bottom: 8px;
}

.progress-message {
  font-size: 14px;
  color: var(--muted);
  margin-bottom: 12px;
}

.progress-bar {
  width: 100%;
  height: 8px;
  background: rgba(42, 77, 123, 0.1);
  border-radius: 4px;
  overflow: hidden;
  margin: 12px 0;
}

.progress-fill {
  height: 100%;
  background: linear-gradient(90deg, var(--primary) 0%, var(--primary-600) 100%);
  border-radius: 4px;
  transition: width 0.3s ease;
  position: relative;
}

.progress-fill::after {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: linear-gradient(90deg, transparent 0%, rgba(255,255,255,0.3) 50%, transparent 100%);
  animation: shimmer 2s infinite;
}

@keyframes shimmer {
  0% { transform: translateX(-100%); }
  100% { transform: translateX(100%); }
}

.progress-percentage {
  font-size: 18px;
  font-weight: 700;
  color: var(--primary-600);
}

/* Estados de error */
.error-container, .warning-container, .success-container {
  text-align: center;
  padding: 16px;
  border-radius: 12px;
  margin: 16px 0;
}

.error-container {
  background: rgba(239, 68, 68, 0.05);
  border: 1px solid rgba(239, 68, 68, 0.2);
}

.warning-container {
  background: rgba(245, 158, 11, 0.05);
  border: 1px solid rgba(245, 158, 11, 0.2);
}

.success-container {
  background: rgba(34, 197, 94, 0.05);
  border: 1px solid rgba(34, 197, 94, 0.2);
}

.error-icon, .warning-icon, .success-icon {
  font-size: 24px;
  margin-bottom: 8px;
  display: block;
}

.error-message, .warning-title, .success-message {
  font-size: 14px;
  font-weight: 600;
  margin-bottom: 4px;
}

.error-message {
  color: #dc2626;
}

.warning-title {
  color: #d97706;
}

.success-message {
  color: #16a34a;
}

.error-suggestion {
  font-size: 12px;
  color: var(--muted);
  margin-top: 4px;
}

.warning-list {
  text-align: left;
  margin: 8px 0 0 0;
  padding-left: 20px;
  font-size: 12px;
  color: #d97706;
}

/* Placeholder para previews */
.preview-placeholder {
  width: 100%;
  height: 120px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 32px;
  background: rgba(42, 77, 123, 0.05);
  border-radius: 8px;
  color: var(--muted);
}

/* Estilos para tamaño de archivo */
.file-size {
  font-size: 10px;
  color: var(--muted);
  font-weight: 500;
}

/* Estilos para archivos encriptados */
.file-encrypted {
  font-size: 9px;
  color: #f59e0b;
  font-weight: 600;
  background: rgba(245, 158, 11, 0.1);
  padding: 2px 6px;
  border-radius: 4px;
  margin-top: 2px;
}

/* Estadísticas de éxito */
.success-stats {
  font-size: 12px;
  color: var(--muted);
  margin-top: 8px;
  line-height: 1.4;
  text-align: left;
  background: rgba(34, 197, 94, 0.05);
  padding: 8px 12px;
  border-radius: 6px;
  border: 1px solid rgba(34, 197, 94, 0.1);
}

/* Notificaciones temporales */
.temp-warning {
  position: fixed;
  top: 20px;
  right: 20px;
  z-index: 1000;
  max-width: 300px;
  animation: slideInRight 0.3s ease-out, slideOutRight 0.3s ease-out 4.7s;
}

@keyframes slideInRight {
  from {
    transform: translateX(100%);
    opacity: 0;
  }
  to {
    transform: translateX(0);
    opacity: 1;
  }
}

@keyframes slideOutRight {
  from {
    transform: translateX(0);
    opacity: 1;
  }
  to {
    transform: translateX(100%);
    opacity: 0;
  }
}

/* Mejoras en la zona de drop durante procesamiento */
.drop-area.processing {
  opacity: 0.6;
  pointer-events: none;
  cursor: not-allowed;
}

/* Estados de botones mejorados */
.btn:disabled {
  background: linear-gradient(180deg, #9ca3af 0%, #6b7280 100%);
  cursor: not-allowed;
  box-shadow: none;
  opacity: 0.9;
  transform: none !important;
}

.btn.processing {
  position: relative;
  overflow: hidden;
}

.btn.processing::after {
  content: '';
  position: absolute;
  top: 0;
  left: -100%;
  width: 100%;
  height: 100%;
  background: linear-gradient(90deg, transparent 0%, rgba(255,255,255,0.2) 50%, transparent 100%);
  animation: buttonShimmer 1.5s infinite;
}

@keyframes buttonShimmer {
  0% { left: -100%; }
  100% { left: 100%; }
}

/* Responsive para dispositivos móviles */
@media (max-width: 640px) {
  .progress-container {
    padding: 16px;
    margin: 12px 0;
  }
  
  .progress-stage {
    font-size: 14px;
  }
  
  .progress-message {
    font-size: 12px;
  }
  
  .progress-percentage {
    font-size: 16px;
  }
  
  .error-container, .warning-container, .success-container {
    padding: 12px;
    margin: 12px 0;
  }
  
  .preview-placeholder {
    height: 100px;
    font-size: 24px;
  }
}

/* Modo oscuro */
@media (prefers-color-scheme: dark) {
  .progress-container {
    background: rgba(42, 77, 123, 0.1);
  }
  
  .error-container {
    background: rgba(239, 68, 68, 0.1);
  }
  
  .warning-container {
    background: rgba(245, 158, 11, 0.1);
  }
  
  .success-container {
    background: rgba(34, 197, 94, 0.1);
  }
  
  .preview-placeholder {
    background: rgba(42, 77, 123, 0.1);
  }
  
  .diagnostic-container {
    background: rgba(59, 130, 246, 0.1);
  }
}

/* Estilos para diagnósticos detallados */
.diagnostic-container {
  background: rgba(59, 130, 246, 0.05);
  border: 1px solid rgba(59, 130, 246, 0.2);
  border-radius: 12px;
  padding: 20px;
  margin: 16px 0;
  text-align: left;
}

.diagnostic-header {
  display: flex;
  align-items: center;
  gap: 12px;
  margin-bottom: 16px;
  padding-bottom: 12px;
  border-bottom: 1px solid rgba(59, 130, 246, 0.2);
}

.diagnostic-icon {
  font-size: 24px;
}

.diagnostic-title {
  font-size: 18px;
  font-weight: 700;
  color: var(--primary-600);
}

.diagnostic-summary {
  background: rgba(59, 130, 246, 0.08);
  padding: 12px;
  border-radius: 8px;
  font-size: 13px;
  line-height: 1.5;
  margin-bottom: 16px;
  color: var(--text);
}

.diagnostic-section {
  margin: 16px 0;
}

.diagnostic-section h4 {
  margin: 0 0 8px 0;
  font-size: 14px;
  font-weight: 600;
  color: var(--text);
}

.diagnostic-section ul {
  margin: 0;
  padding-left: 20px;
  font-size: 13px;
  color: var(--muted);
}

.diagnostic-section li {
  margin: 4px 0;
}

.file-diagnostic {
  background: rgba(239, 68, 68, 0.05);
  border: 1px solid rgba(239, 68, 68, 0.1);
  border-radius: 6px;
  padding: 10px;
  margin: 8px 0;
}

.file-diagnostic strong {
  color: var(--text);
  font-size: 13px;
}

.file-issues {
  margin: 6px 0 0 0 !important;
  padding-left: 16px !important;
}

.file-issues li {
  color: #dc2626;
  font-size: 12px;
}

.diagnostic-footer {
  margin-top: 16px;
  padding-top: 12px;
  border-top: 1px solid rgba(59, 130, 246, 0.2);
  font-size: 14px;
  color: var(--text);
}

/* Estilos para errores categorizados */
.error-category {
  font-size: 12px;
  font-weight: 700;
  color: #dc2626;
  text-transform: uppercase;
  letter-spacing: 0.5px;
  margin-bottom: 6px;
}

.error-recommendation {
  margin-top: 12px;
  padding: 10px;
  background: rgba(59, 130, 246, 0.05);
  border-radius: 6px;
  font-size: 13px;
  line-height: 1.4;
}

.error-recommendation strong {
  color: var(--primary-600);
}

.error-details {
  margin-top: 12px;
  font-size: 12px;
}

.error-details summary {
  cursor: pointer;
  font-weight: 600;
  color: var(--muted);
  padding: 6px 0;
}

.error-details pre {
  background: rgba(0, 0, 0, 0.05);
  padding: 8px;
  border-radius: 4px;
  font-size: 11px;
  overflow-x: auto;
  margin: 6px 0 0 0;
  color: var(--muted);
  white-space: pre-wrap;
}

/* Severidad de errores */
.error-container.critical {
  border-color: #dc2626;
  background: rgba(220, 38, 38, 0.08);
}

.error-container.high {
  border-color: #ea580c;
  background: rgba(234, 88, 12, 0.08);
}

.error-container.medium {
  border-color: #d97706;
  background: rgba(217, 119, 6, 0.08);
}

.error-container.critical .error-category {
  color: #dc2626;
}

.error-container.high .error-category {
  color: #ea580c;
}

.error-container.medium .error-category {
  color: #d97706;
}

/* Responsive para diagnósticos */
@media (max-width: 640px) {
  .diagnostic-container {
    padding: 16px;
    margin: 12px 0;
  }
  
  .diagnostic-header {
    flex-direction: column;
    align-items: flex-start;
    gap: 8px;
  }
  
  .diagnostic-title {
    font-size: 16px;
  }
  
  .diagnostic-summary {
    font-size: 12px;
    padding: 10px;
  }
  
  .file-diagnostic {
    padding: 8px;
  }
  
  .error-recommendation {
    padding: 8px;
    font-size: 12px;
  }
}