:root {
  --purple-50: #faf5ff;
  --purple-100: #f3e8ff;
  --purple-200: #e9d5ff;
  --purple-300: #d8b4fe;
  --purple-400: #c084fc;
  --purple-500: #a855f7;
  --purple-600: #9333ea;
  --purple-700: #7e22ce;
  --purple-800: #6b21a8;
  --purple-900: #581c87;
  --pink-300: #f9a8d4;
  --white: #ffffff;
  --shadow: 0 8px 32px rgba(147, 51, 234, 0.15);
  --radius: 20px;
  --radius-sm: 12px;
}

* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

body {
  font-family: 'Nunito', -apple-system, sans-serif;
  min-height: 100vh;
  background: linear-gradient(135deg, var(--purple-50) 0%, var(--purple-100) 50%, var(--purple-200) 100%);
  color: var(--purple-900);
  padding: 2rem 1rem;
  position: relative;
  overflow-x: hidden;
}

.bg-decoration {
  position: fixed;
  inset: 0;
  pointer-events: none;
  background-image: 
    radial-gradient(circle at 20% 30%, rgba(216, 180, 254, 0.3) 0%, transparent 50%),
    radial-gradient(circle at 80% 70%, rgba(249, 168, 212, 0.25) 0%, transparent 50%);
  z-index: 0;
}

.container {
  max-width: 560px;
  margin: 0 auto;
  position: relative;
  z-index: 1;
}

.header {
  text-align: center;
  margin-bottom: 2rem;
}

.title {
  font-size: 1.75rem;
  font-weight: 700;
  color: var(--purple-700);
  margin-bottom: 0.5rem;
  text-shadow: 0 2px 4px rgba(126, 34, 206, 0.1);
}

.subtitle {
  font-size: 0.95rem;
  color: var(--purple-600);
  opacity: 0.9;
}

.tabs {
  display: flex;
  gap: 0.5rem;
  margin-bottom: 1.5rem;
  background: var(--white);
  padding: 6px;
  border-radius: var(--radius);
  box-shadow: var(--shadow);
}

.tab {
  flex: 1;
  padding: 0.75rem 1rem;
  border: none;
  border-radius: var(--radius-sm);
  font-family: inherit;
  font-size: 0.95rem;
  font-weight: 600;
  color: var(--purple-600);
  background: transparent;
  cursor: pointer;
  transition: all 0.25s ease;
}

.tab:hover {
  color: var(--purple-700);
  background: var(--purple-100);
}

.tab.active {
  background: linear-gradient(135deg, var(--purple-500), var(--purple-600));
  color: var(--white);
  box-shadow: 0 4px 12px rgba(147, 51, 234, 0.35);
}

.panel {
  display: none;
  background: var(--white);
  border-radius: var(--radius);
  padding: 1.5rem;
  box-shadow: var(--shadow);
}

.panel.active {
  display: block;
  animation: fadeIn 0.3s ease;
}

@keyframes fadeIn {
  from { opacity: 0; transform: translateY(8px); }
  to { opacity: 1; transform: translateY(0); }
}

.upload-zone {
  border: 2px dashed var(--purple-300);
  border-radius: var(--radius-sm);
  padding: 2rem;
  text-align: center;
  cursor: pointer;
  transition: all 0.25s ease;
  background: var(--purple-50);
  margin-bottom: 1rem;
}

.upload-zone:hover,
.upload-zone.dragover {
  border-color: var(--purple-500);
  background: var(--purple-100);
}

.upload-content {
  pointer-events: none;
}

.upload-icon {
  font-size: 3rem;
  display: block;
  margin-bottom: 0.5rem;
}

.upload-text {
  font-weight: 600;
  color: var(--purple-700);
  margin-bottom: 0.25rem;
}

.upload-hint {
  font-size: 0.85rem;
  color: var(--purple-600);
  opacity: 0.8;
}

.preview-area {
  min-height: 80px;
  margin-bottom: 1rem;
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  align-items: flex-start;
}

.preview-area .thumb {
  width: 64px;
  height: 64px;
  object-fit: cover;
  border-radius: 8px;
  border: 2px solid var(--purple-200);
}

.preview-area .thumb-pdf {
  max-width: 120px;
  max-height: 120px;
}

.actions {
  display: flex;
  gap: 0.75rem;
  flex-wrap: wrap;
}

.btn {
  flex: 1;
  min-width: 140px;
  padding: 0.85rem 1.25rem;
  border: none;
  border-radius: var(--radius-sm);
  font-family: inherit;
  font-size: 0.95rem;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.25s ease;
}

.btn-convert {
  background: linear-gradient(135deg, var(--purple-500), var(--purple-600));
  color: var(--white);
  box-shadow: 0 4px 14px rgba(147, 51, 234, 0.4);
}

.btn-convert:hover:not(:disabled) {
  transform: translateY(-2px);
  box-shadow: 0 6px 20px rgba(147, 51, 234, 0.5);
}

.btn-download {
  background: linear-gradient(135deg, var(--pink-300), var(--purple-400));
  color: var(--white);
}

.btn-download:hover:not(:disabled) {
  transform: translateY(-2px);
  box-shadow: 0 6px 20px rgba(192, 132, 252, 0.4);
}

.btn:disabled {
  opacity: 0.5;
  cursor: not-allowed;
  transform: none;
}

.status-msg {
  font-size: 0.9rem;
  color: var(--purple-600);
  margin-top: 0.5rem;
}

.error-msg {
  color: #dc2626;
}