* {
  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;
  padding: 20px;
  color: #333;
}

.container {
  max-width: 900px;
  margin: 0 auto;
}

header {
  text-align: center;
  color: white;
  margin-bottom: 30px;
}

header h1 {
  font-size: 2.5em;
  margin-bottom: 10px;
  text-shadow: 2px 2px 4px rgba(0, 0, 0, 0.2);
}

.subtitle {
  font-size: 1.1em;
  opacity: 0.9;
}

.tabs {
  display: flex;
  gap: 10px;
  margin-bottom: 20px;
}

.tab {
  flex: 1;
  padding: 15px;
  background: rgba(255, 255, 255, 0.2);
  color: white;
  border: none;
  border-radius: 8px 8px 0 0;
  font-size: 1em;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.3s ease;
}

.tab:hover {
  background: rgba(255, 255, 255, 0.3);
}

.tab.active {
  background: white;
  color: #667eea;
}

.section {
  display: none;
}

.section.active {
  display: block;
}

.card {
  background: white;
  border-radius: 0 8px 8px 8px;
  padding: 30px;
  box-shadow: 0 10px 40px rgba(0, 0, 0, 0.2);
}

.card h2 {
  color: #667eea;
  margin-bottom: 15px;
  font-size: 1.8em;
}

.info {
  color: #666;
  margin-bottom: 25px;
  line-height: 1.6;
}

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

.input-group label {
  display: block;
  margin-bottom: 8px;
  font-weight: 600;
  color: #555;
}

textarea {
  width: 100%;
  padding: 12px;
  border: 2px solid #e0e0e0;
  border-radius: 6px;
  font-family: 'Courier New', monospace;
  font-size: 14px;
  resize: vertical;
  transition: border-color 0.3s ease;
}

textarea:focus {
  outline: none;
  border-color: #667eea;
}

input[type="file"] {
  width: 100%;
  padding: 10px;
  border: 2px dashed #e0e0e0;
  border-radius: 6px;
  cursor: pointer;
  transition: border-color 0.3s ease;
}

input[type="file"]:hover {
  border-color: #667eea;
}

select {
  width: 100%;
  padding: 10px 12px;
  border: 2px solid #e0e0e0;
  border-radius: 6px;
  font-size: 1em;
  background: white;
  cursor: pointer;
  transition: border-color 0.3s ease;
}

select:focus {
  outline: none;
  border-color: #667eea;
}

.btn {
  padding: 12px 30px;
  border: none;
  border-radius: 6px;
  font-size: 1em;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.3s ease;
  margin-right: 10px;
}

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

.btn-primary {
  background: #667eea;
  color: white;
}

.btn-primary:hover:not(:disabled) {
  background: #5568d3;
  transform: translateY(-2px);
  box-shadow: 0 5px 15px rgba(102, 126, 234, 0.3);
}

.btn-secondary {
  background: #48bb78;
  color: white;
}

.btn-secondary:hover:not(:disabled) {
  background: #38a169;
  transform: translateY(-2px);
  box-shadow: 0 5px 15px rgba(72, 187, 120, 0.3);
}

.result-area {
  margin-top: 30px;
  padding-top: 30px;
  border-top: 2px solid #f0f0f0;
}

.result-area h3 {
  color: #667eea;
  margin-bottom: 15px;
}

.canvas-container {
  background: #f5f5f5;
  border: 2px solid #e0e0e0;
  border-radius: 6px;
  padding: 20px;
  text-align: center;
  margin-bottom: 15px;
  min-height: 200px;
  display: flex;
  align-items: center;
  justify-content: center;
}

#preview-canvas {
  max-width: 100%;
  height: auto;
  image-rendering: pixelated;
  border: 1px solid #ddd;
}

.image-info {
  color: #666;
  font-size: 0.9em;
  margin-bottom: 15px;
}

footer {
  text-align: center;
  color: white;
  margin-top: 30px;
  padding: 20px;
  opacity: 0.9;
}

footer p {
  margin: 10px 0;
  line-height: 1.6;
}

.github-link a {
  color: white;
  text-decoration: none;
  font-weight: 600;
  border-bottom: 2px solid rgba(255, 255, 255, 0.5);
  padding-bottom: 2px;
  transition: border-color 0.3s ease;
}

.github-link a:hover {
  border-color: white;
}

@media (max-width: 768px) {
  header h1 {
    font-size: 2em;
  }

  .card {
    padding: 20px;
  }

  .tabs {
    flex-direction: column;
  }

  .tab {
    border-radius: 8px;
  }

  .tab.active {
    border-radius: 8px;
  }
}