.container {
  margin: 0 auto;
  border-radius: 16px;
  padding: 40px;
  max-width: 900px;
  width: 100%;
}

h1 {
  font-size: 32px;
  color: #2d3748;
  margin: 0px;
  text-align: center;
}

.subtitle {
  text-align: center;
  color: #718096;
}

.method-selector {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 15px;
  margin-bottom: 30px;
}

.method-card {
  border: 2px solid #e2e8f0;
  border-radius: 12px;
  padding: 20px;
  cursor: pointer;
  transition: all 0.3s;
  text-align: center;
}

.method-card:hover {
  border-color: #667eea;
  transform: translateY(-2px);
  box-shadow: 0 4px 12px rgba(102, 126, 234, 0.2);
}

.method-card.active {
  border-color: #667eea;
  background: linear-gradient(135deg, #667eea15, #764ba215);
}

.method-title {
  font-weight: 600;
  font-size: 18px;
  margin-bottom: 8px;
  color: #2d3748;
}

.method-desc {
  font-size: 13px;
  color: #718096;
  line-height: 1.5;
}

.upload-area {
  border: 3px dashed #cbd5e0;
  border-radius: 12px;
  padding: 20px 20px;
  text-align: center;
  cursor: pointer;
  transition: all 0.3s;
  margin-bottom: 20px;
}

.upload-area:hover {
  border-color: #667eea;
  background: #f7fafc;
}

.upload-btn {
  display: inline-block;
  background: linear-gradient(135deg, #667eea, #764ba2);
  color: white;
  padding: 12px 32px;
  border-radius: 8px;
  cursor: pointer;
  font-weight: 600;
  transition: transform 0.2s;
}

.upload-btn:hover {
  transform: scale(1.05);
}

#fileInput {
  display: none;
}

#fileInfo {
  display: flex;
  justify-content: space-between;
  background: #f0f0f0;
  padding: 35px;
  border-radius: 6px;
}

.file-remove-btn {
  background: #ff4757;
  color: white;
  border: none;
  padding: 5px 12px;
  border-radius: 5px;
  cursor: pointer;
  font-size: 12px;
  transition: background 0.3s;
}

.file-remove-btn:hover {
  background: #ff3838;
}

.settings-section {
  background: #f7fafc;
  border-radius: 12px;
}

.settings-section h3 {
  color: #2d3748;
  margin-bottom: 20px;
}

.setting-group {
  margin-bottom: 20px;
}

.setting-group label {
  display: block;
  font-weight: 600;
  color: #4a5568;
  margin-bottom: 8px;
  font-size: 14px;
}

.setting-group select,
.setting-group input[type="range"] {
  width: 100%;
  padding: 10px;
  border: 2px solid #e2e8f0;
  border-radius: 8px;
  font-size: 14px;
  background: white;
}

.setting-group input[type="range"] {
  padding: 0;
}

.range-value {
  display: inline-block;
  font-weight: 600;
  color: #667eea;
  margin-left: 10px;
}

.quality-preview {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-top: 5px;
  font-size: 12px;
  color: #718096;
}

.convert-btn {
  width: 100%;
  background: linear-gradient(135deg, #667eea, #764ba2);
  color: white;
  padding: 16px;
  border: none;
  border-radius: 8px;
  font-size: 16px;
  font-weight: 600;
  cursor: pointer;
  transition: transform 0.2s;
  margin-bottom: 20px;
}

.convert-btn:hover:not(:disabled) {
  transform: translateY(-2px);
  box-shadow: 0 6px 20px rgba(102, 126, 234, 0.4);
}

.convert-btn:disabled {
  opacity: 0.5;
  cursor: not-allowed;
}

.error-section {
  display: none;
  background: #fff5f5;
  border: 2px solid #fc8181;
  border-radius: 12px;
  padding: 20px;
  margin-bottom: 20px;
  animation: slideDown 0.3s ease-out;
}

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

.error-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 10px;
}

.error-title {
  display: flex;
  align-items: center;
  gap: 10px;
  font-weight: 600;
  color: #c53030;
  font-size: 16px;
}

.error-close {
  background: none;
  border: none;
  font-size: 24px;
  color: #c53030;
  cursor: pointer;
  padding: 0;
  width: 30px;
  height: 30px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 4px;
  transition: background 0.2s;
}

.error-close:hover {
  background: #feb2b2;
}

.error-message {
  color: #742a2a;
  font-size: 14px;
  line-height: 1.5;
}

.progress-section {
  display: none;
  margin-bottom: 20px;
}

.progress-bar {
  width: 100%;
  height: 40px;
  background: #e2e8f0;
  border-radius: 20px;
  overflow: hidden;
  margin-bottom: 10px;
}

.progress-fill {
  height: 100%;
  background: linear-gradient(90deg, #667eea, #764ba2);
  transition: width 0.3s;
  display: flex;
  align-items: center;
  justify-content: center;
  color: white;
  font-weight: 600;
}

.result-section {
  display: none;
  background: #f0fff4;
  padding: 30px;
  border-radius: 12px;
  border: 2px solid #9ae6b4;
  margin-bottom: 20px;
}

.stat-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 15px;
  margin: 20px 0;
}

.stat-box {
  background: white;
  padding: 20px;
  border-radius: 8px;
  text-align: center;
}

.stat-label {
  font-size: 12px;
  color: #718096;
  margin-bottom: 8px;
  text-transform: uppercase;
  font-weight: 600;
}

.stat-value {
  font-size: 24px;
  font-weight: 700;
  color: #2d3748;
}

.download-btn {
  width: 100%;
  background: #48bb78;
  color: white;
  padding: 14px;
  border: none;
  border-radius: 8px;
  font-size: 16px;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.2s;
}

.download-btn:hover {
  background: #38a169;
  transform: translateY(-2px);
}

.alert {
  padding: 20px;
  border-radius: 8px;
  font-size: 14px;
  line-height: 1.6;
}

.alert-info {
  background: #ebf8ff;
  border: 1px solid #90cdf4;
  color: #2c5282;
}

.hidden {
  display: none !important;
}

.settingContainer {
  display: flex;
  gap: 15px;
  justify-content: space-around;
}

.help-section {
  background-color: #f8f9fa;
  border: 1px solid #e0e0e0;
  border-left: 5px solid #0d6efd;
  padding: 20px;
  border-radius: 10px;
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.05);
  padding: 100px;
  margin: 10px;
}

.help-section h3 {
  font-size: 22px;
  color: #0d6efd;
  margin-bottom: 15px;
}

.help-section p {
  color: #333;
  font-size: 18px;
  line-height: 1.7;
  margin-bottom: 12px;
}

.help-section ul {
  padding-left: 20px;
  margin: 0;
}

.help-section li {
  margin-bottom: 10px;
  font-size: 1rem;
  line-height: 1.6;
}

.help-section hr {
  margin: 20px 0;
  border: none;
  border-top: 1px solid #ccc;
}