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

:root {
  --primary-color: #3b82f6;
  --primary-hover: #2563eb;
  --text-color: #1f2937;
  --text-light: #6b7280;
  --bg-color: #ffffff;
  --bg-gray: #f9fafb;
  --border-color: #e5e7eb;
  --success-color: #10b981;
  --shadow: 0 1px 3px rgba(0, 0, 0, 0.1);
  --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
}

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
  color: var(--text-color);
  background: var(--bg-color);
  line-height: 1.6;
}

.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 20px;
}

.hidden {
  display: none !important;
}

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

.header .container {
  display: flex;
  justify-content: space-between;
  align-items: center;
  height: 64px;
}

.logo {
  display: flex;
  align-items: center;
  gap: 10px;
  text-decoration: none;
  color: var(--text-color);
  font-size: 20px;
  font-weight: 600;
}

.logo svg {
  color: var(--primary-color);
}

.nav {
  display: flex;
  align-items: center;
  gap: 20px;
}

.lang-select {
  padding: 6px 12px;
  border: 1px solid var(--border-color);
  border-radius: 6px;
  background: var(--bg-color);
  color: var(--text-color);
  cursor: pointer;
  font-size: 14px;
}

/* Hero Section */
.hero {
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  color: white;
  padding: 80px 0;
  text-align: center;
}

.hero h1 {
  font-size: 42px;
  margin-bottom: 16px;
  font-weight: 700;
}

.hero p {
  font-size: 18px;
  margin-bottom: 24px;
  opacity: 0.95;
}

.badges {
  display: flex;
  justify-content: center;
  gap: 16px;
  flex-wrap: wrap;
}

.badge {
  background: rgba(255, 255, 255, 0.2);
  padding: 8px 16px;
  border-radius: 20px;
  font-size: 14px;
  backdrop-filter: blur(10px);
}

/* Tools Section */
.tools-section {
  padding: 60px 0;
  background: var(--bg-gray);
}

.tools-section h2 {
  text-align: center;
  font-size: 32px;
  margin-bottom: 24px;
}

.search-input {
  width: 100%;
  max-width: 500px;
  margin: 0 auto 40px;
  padding: 12px 20px;
  border: 2px solid var(--border-color);
  border-radius: 8px;
  font-size: 16px;
  transition: border-color 0.2s;
}

.search-input:focus {
  outline: none;
  border-color: var(--primary-color);
}

.tools-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 20px;
}

.tool-card {
  background: var(--bg-color);
  border: 1px solid var(--border-color);
  border-radius: 12px;
  padding: 24px;
  transition: all 0.2s;
  cursor: pointer;
  text-decoration: none;
  color: var(--text-color);
  display: block;
}

.tool-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-lg);
  border-color: var(--primary-color);
}

.tool-card-header {
  display: flex;
  align-items: center;
  gap: 12px;
  margin-bottom: 12px;
}

.tool-icon {
  width: 48px;
  height: 48px;
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  border-radius: 10px;
  display: flex;
  align-items: center;
  justify-content: center;
  color: white;
  font-weight: 600;
  font-size: 12px;
}

.tool-card h3 {
  font-size: 18px;
  margin: 0;
}

.tool-card p {
  color: var(--text-light);
  font-size: 14px;
  line-height: 1.5;
}

/* Features Section */
.features-section {
  padding: 60px 0;
}

.features-section h2 {
  text-align: center;
  font-size: 32px;
  margin-bottom: 40px;
}

.features-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: 30px;
}

.feature-card {
  text-align: center;
  padding: 30px 20px;
}

.feature-icon {
  font-size: 48px;
  margin-bottom: 16px;
}

.feature-card h3 {
  font-size: 20px;
  margin-bottom: 12px;
}

.feature-card p {
  color: var(--text-light);
  font-size: 15px;
}

/* Convert Page */
.convert-header {
  text-align: center;
  padding: 40px 0;
}

.convert-header h1 {
  font-size: 36px;
  margin-bottom: 12px;
}

.convert-header p {
  color: var(--text-light);
  font-size: 16px;
}

.convert-area {
  max-width: 800px;
  margin: 0 auto;
}

/* Upload Area */
.upload-area {
  border: 2px dashed var(--border-color);
  border-radius: 12px;
  padding: 60px 20px;
  text-align: center;
  cursor: pointer;
  transition: all 0.2s;
  background: var(--bg-gray);
}

.upload-area:hover,
.upload-area.dragover {
  border-color: var(--primary-color);
  background: #f0f9ff;
}

.upload-icon {
  color: var(--primary-color);
  margin-bottom: 16px;
}

.upload-area p {
  font-size: 16px;
  margin-bottom: 8px;
}

.upload-hint {
  color: var(--text-light);
  font-size: 14px;
}

.file-input {
  display: none;
}

/* Settings Area */
.settings-area {
  background: var(--bg-gray);
  border: 1px solid var(--border-color);
  border-radius: 12px;
  padding: 24px;
  margin-top: 20px;
}

.setting-group {
  margin-bottom: 16px;
}

.setting-group:last-child {
  margin-bottom: 0;
}

.setting-group label {
  display: block;
  font-weight: 600;
  margin-bottom: 12px;
}

.quality-control {
  display: flex;
  align-items: center;
  gap: 16px;
}

.quality-control input[type="range"] {
  flex: 1;
  height: 6px;
  border-radius: 3px;
  background: var(--border-color);
  outline: none;
  -webkit-appearance: none;
}

.quality-control input[type="range"]::-webkit-slider-thumb {
  -webkit-appearance: none;
  width: 20px;
  height: 20px;
  border-radius: 50%;
  background: var(--primary-color);
  cursor: pointer;
}

.quality-control span {
  min-width: 50px;
  font-weight: 600;
  color: var(--primary-color);
}

.setting-hint {
  color: var(--text-light);
  font-size: 13px;
  margin-top: 8px;
}

/* File List */
.file-list {
  margin-top: 20px;
}

.file-item {
  background: var(--bg-gray);
  border: 1px solid var(--border-color);
  border-radius: 8px;
  padding: 16px;
  margin-bottom: 12px;
  display: flex;
  align-items: center;
  gap: 16px;
}

.file-preview {
  width: 60px;
  height: 60px;
  border-radius: 6px;
  object-fit: cover;
  background: var(--border-color);
}

.file-info {
  flex: 1;
}

.file-name {
  font-weight: 600;
  margin-bottom: 4px;
  word-break: break-all;
}

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

.file-status {
  padding: 4px 12px;
  border-radius: 12px;
  font-size: 13px;
  font-weight: 600;
}

.file-status.pending {
  background: #fef3c7;
  color: #92400e;
}

.file-status.converting {
  background: #dbeafe;
  color: #1e40af;
}

.file-status.done {
  background: #d1fae5;
  color: #065f46;
}

.file-status.error {
  background: #fee2e2;
  color: #991b1b;
}

.file-remove {
  background: none;
  border: none;
  color: var(--text-light);
  cursor: pointer;
  padding: 8px;
  border-radius: 6px;
  transition: all 0.2s;
}

.file-remove:hover {
  background: var(--border-color);
  color: var(--text-color);
}

/* Action Buttons */
.action-buttons {
  display: flex;
  gap: 12px;
  margin-top: 24px;
  justify-content: center;
}

.btn {
  padding: 12px 32px;
  border: none;
  border-radius: 8px;
  font-size: 16px;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.2s;
}

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

.btn-primary:hover {
  background: var(--primary-hover);
  transform: translateY(-2px);
  box-shadow: var(--shadow-lg);
}

.btn-primary:disabled {
  background: var(--border-color);
  cursor: not-allowed;
  transform: none;
}

.btn-secondary {
  background: var(--bg-gray);
  color: var(--text-color);
  border: 1px solid var(--border-color);
}

.btn-secondary:hover {
  background: var(--border-color);
}

/* Progress Area */
.progress-area {
  margin-top: 24px;
  text-align: center;
}

.progress-bar {
  width: 100%;
  height: 8px;
  background: var(--border-color);
  border-radius: 4px;
  overflow: hidden;
  margin-bottom: 12px;
}

.progress-fill {
  height: 100%;
  background: linear-gradient(90deg, var(--primary-color), var(--success-color));
  width: 0%;
  transition: width 0.3s;
}

.progress-text {
  color: var(--text-light);
  font-size: 14px;
}

/* Result Area */
.result-area {
  margin-top: 30px;
  padding: 30px;
  background: #f0fdf4;
  border: 2px solid var(--success-color);
  border-radius: 12px;
  text-align: center;
}

.result-area h3 {
  color: var(--success-color);
  margin-bottom: 20px;
  font-size: 24px;
}

.result-list {
  margin-bottom: 24px;
}

.result-item {
  background: var(--bg-color);
  border: 1px solid var(--border-color);
  border-radius: 8px;
  padding: 16px;
  margin-bottom: 12px;
  display: flex;
  align-items: center;
  gap: 16px;
}

.result-preview {
  width: 60px;
  height: 60px;
  border-radius: 6px;
  object-fit: cover;
}

.result-info {
  flex: 1;
  text-align: left;
}

.result-name {
  font-weight: 600;
  margin-bottom: 4px;
}

.result-size {
  color: var(--text-light);
  font-size: 13px;
}

.result-download {
  padding: 8px 16px;
  background: var(--primary-color);
  color: white;
  border: none;
  border-radius: 6px;
  cursor: pointer;
  font-weight: 600;
  transition: all 0.2s;
}

.result-download:hover {
  background: var(--primary-hover);
}

/* Other Conversions */
.other-conversions {
  margin-top: 60px;
  padding-top: 40px;
  border-top: 1px solid var(--border-color);
}

.other-conversions h3 {
  text-align: center;
  margin-bottom: 24px;
  font-size: 24px;
}

.other-links {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  justify-content: center;
}

.other-links a {
  padding: 8px 16px;
  background: var(--bg-gray);
  border: 1px solid var(--border-color);
  border-radius: 6px;
  text-decoration: none;
  color: var(--text-color);
  font-size: 14px;
  transition: all 0.2s;
}

.other-links a:hover {
  background: var(--primary-color);
  color: white;
  border-color: var(--primary-color);
}

/* Footer */
.footer {
  background: var(--bg-gray);
  border-top: 1px solid var(--border-color);
  padding: 30px 0;
  text-align: center;
  color: var(--text-light);
  font-size: 14px;
}

/* Responsive */
@media (max-width: 768px) {
  .hero h1 {
    font-size: 28px;
  }

  .hero p {
    font-size: 16px;
  }

  .tools-grid {
    grid-template-columns: 1fr;
  }

  .features-grid {
    grid-template-columns: 1fr;
  }

  .action-buttons {
    flex-direction: column;
  }

  .btn {
    width: 100%;
  }
}