/* Reset & Base */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

body {
  font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
  line-height: 1.6;
  color: #333;
  background-color: #f8f9fa;
}

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

/* Hero Section */
.hero {
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  color: white;
  padding: 4rem 0;
  text-align: center;
}
.hero h1 {
  font-size: 2.5rem;
  margin-bottom: 1rem;
  font-weight: 700;
}
.tagline {
  font-size: 1.2rem;
  opacity: 0.9;
  max-width: 600px;
  margin: 0 auto;
}

/* Tool Section */
.tool-section {
  padding: 3rem 0;
  background: white;
  margin: 2rem 0;
  border-radius: 12px;
  box-shadow: 0 4px 6px rgba(0,0,0,0.1);
}
.tool-section h2 {
  text-align: center;
  margin-bottom: 2rem;
  color: #2c3e50;
}
.upload-box {
  border: 3px dashed #667eea;
  border-radius: 12px;
  padding: 3rem;
  text-align: center;
  cursor: pointer;
  transition: all 0.3s ease;
  background: #f8f9ff;
}
.upload-box:hover {
  border-color: #764ba2;
  background: #f0f4ff;
}
.upload-box p {
  font-size: 1.1rem;
  color: #666;
}

/* Preview */
.preview {
  margin-top: 2rem;
  text-align: center;
}
.preview.hidden { display: none; }
.preview img {
  max-width: 400px;
  max-height: 300px;
  border-radius: 8px;
  box-shadow: 0 4px 8px rgba(0,0,0,0.1);
  margin-bottom: 1rem;
}
.buttons {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  justify-content: center;
  margin-top: 1rem;
}
.convert-btn {
  padding: 0.7rem 1.2rem;
  border: none;
  border-radius: 6px;
  background: #667eea;
  color: white;
  cursor: pointer;
  font-weight: 500;
  transition: background 0.3s ease;
}
.convert-btn:hover {
  background: #5a6fd8;
}

/* Sections */
.section {
  background: white;
  margin: 2rem 0;
  padding: 3rem 0;
  border-radius: 12px;
  box-shadow: 0 2px 4px rgba(0,0,0,0.05);
}
.section h2 {
  color: #2c3e50;
  margin-bottom: 2rem;
  font-size: 2rem;
}
.section h3 {
  color: #34495e;
  margin: 1.5rem 0 1rem 0;
  font-size: 1.3rem;
}
.section ul, .section ol {
  margin-left: 2rem;
  margin-bottom: 1rem;
}
.section li { margin-bottom: 0.5rem; }

/* Tables */
.comparison-table, .format-table {
  width: 100%;
  border-collapse: collapse;
  margin: 2rem 0;
  background: white;
  border-radius: 8px;
  overflow: hidden;
  box-shadow: 0 2px 8px rgba(0,0,0,0.1);
}
.comparison-table th, .format-table th,
.comparison-table td, .format-table td {
  padding: 1rem;
  text-align: left;
  border-bottom: 1px solid #eee;
}
.comparison-table th, .format-table th {
  background: #667eea;
  color: white;
  font-weight: 600;
}
.comparison-table tr:hover, .format-table tr:hover {
  background: #f8f9ff;
}

/* FAQ */
.faq {
  background: white;
  margin: 2rem 0;
  padding: 3rem 0;
  border-radius: 12px;
  box-shadow: 0 2px 4px rgba(0,0,0,0.05);
}
.faq details {
  margin-bottom: 1rem;
  border: 1px solid #eee;
  border-radius: 8px;
  overflow: hidden;
}
.faq summary {
  padding: 1rem;
  background: #f8f9fa;
  cursor: pointer;
  font-weight: 600;
  color: #2c3e50;
}
.faq summary:hover { background: #e9ecef; }
.faq p { padding: 1rem; margin: 0; }

/* Footer */
.footer {
  background: #2c3e50;
  color: white;
  padding: 2rem 0;
  text-align: center;
  margin-top: 3rem;
}
.footer nav a {
  color: #bdc3c7;
  text-decoration: none;
  margin: 0 0.5rem;
}
.footer nav a:hover { color: white; }

/* Responsive */
@media (max-width: 768px) {
  .hero h1 { font-size: 2rem; }
  .tagline { font-size: 1rem; }
  .buttons { flex-direction: column; align-items: center; }
  .convert-btn { width: 200px; }
}