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

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  min-height: 100vh;
  display: flex;
  justify-content: center;
  align-items: center;
  padding: 20px;
}

.container {
  background: white;
  border-radius: 20px;
  padding: 40px;
  max-width: 800px;
  width: 100%;
  box-shadow: 0 20px 60px rgba(0, 0, 0, 0.3);
}

h1 {
  text-align: center;
  color: #333;
  margin-bottom: 10px;
  font-size: 2.5em;
}

.subtitle {
  text-align: center;
  color: #666;
  margin-bottom: 30px;
  font-size: 0.95em;
}

.upload-area {
  border: 3px dashed #667eea;
  border-radius: 15px;
  padding: 60px 40px;
  text-align: center;
  cursor: pointer;
  transition: all 0.3s ease;
  position: relative;
  background: #f8f9ff;
}

.upload-area:hover {
  border-color: #764ba2;
  background: #f0f2ff;
  transform: scale(1.02);
}

.upload-area.dragover {
  border-color: #764ba2;
  background: #e8ebff;
  transform: scale(1.02);
}

.upload-icon {
  width: 80px;
  height: 80px;
  margin: 0 auto 20px;
  color: #667eea;
  stroke-width: 2;
}

.upload-text {
  color: #555;
  font-size: 1.2em;
  font-weight: 500;
}

#fileInput {
  display: none;
}

.file-info {
  background: #f8f9ff;
  border-radius: 10px;
  padding: 20px;
  margin: 20px 0;
}

.file-info h3 {
  color: #333;
  margin-bottom: 15px;
}

.file-info p {
  color: #555;
  margin: 8px 0;
  font-size: 1em;
}

.file-info strong {
  color: #333;
  min-width: 100px;
  display: inline-block;
}

.conversion-options {
  margin: 30px 0;
}

.conversion-options h3 {
  color: #333;
  margin-bottom: 20px;
  text-align: center;
}

.format-buttons {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(120px, 1fr));
  gap: 15px;
}

.format-btn {
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  color: white;
  border: none;
  padding: 15px 20px;
  border-radius: 10px;
  font-size: 1em;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.3s ease;
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

.format-btn:hover {
  transform: translateY(-3px);
  box-shadow: 0 10px 25px rgba(102, 126, 234, 0.4);
}

.format-btn:active {
  transform: translateY(-1px);
}

.progress-area {
  margin: 30px 0;
}

.progress-bar {
  width: 100%;
  height: 30px;
  background: #e0e0e0;
  border-radius: 15px;
  overflow: hidden;
  margin-bottom: 15px;
}

.progress-fill {
  height: 100%;
  background: linear-gradient(90deg, #667eea 0%, #764ba2 100%);
  width: 0%;
  transition: width 0.3s ease;
  display: flex;
  align-items: center;
  justify-content: center;
  color: white;
  font-weight: bold;
}

.progress-text {
  text-align: center;
  color: #555;
  font-weight: 500;
}

.result-area {
  text-align: center;
  margin-top: 30px;
  padding: 30px;
  background: #f0fff4;
  border-radius: 15px;
  border: 2px solid #48bb78;
}

.result-area h3 {
  color: #2f855a;
  margin-bottom: 20px;
}

.download-btn {
  background: linear-gradient(135deg, #48bb78 0%, #38a169 100%);
  color: white;
  border: none;
  padding: 15px 40px;
  border-radius: 10px;
  font-size: 1.1em;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.3s ease;
  margin: 10px;
}

.download-btn:hover {
  transform: translateY(-3px);
  box-shadow: 0 10px 25px rgba(72, 187, 120, 0.4);
}

.reset-btn {
  background: #718096;
  color: white;
  border: none;
  padding: 15px 40px;
  border-radius: 10px;
  font-size: 1.1em;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.3s ease;
  margin: 10px;
}

.reset-btn:hover {
  background: #4a5568;
  transform: translateY(-3px);
}

@media (max-width: 600px) {
  .container {
    padding: 20px;
  }
  
  h1 {
    font-size: 1.8em;
  }
  
  .format-buttons {
    grid-template-columns: repeat(auto-fill, minmax(100px, 1fr));
  }
}