:root {
  --primary: #4361ee;
  --primary-hover: #3a56d4;
  --secondary: #f8f9fa;
  --text: #212529;
  --text-light: #6c757d;
  --background: #ffffff;
  --card-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
  --transition: all 0.2s ease;
}

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

body {
  font-family: 'Inter', system-ui, -apple-system, sans-serif;
  background-color: #f5f7fb;
  color: var(--text);
  line-height: 1.6;
  min-height: 100vh;
}

header {
  background: linear-gradient(135deg, #3a0ca3 0%, #4361ee 100%);
  color: white;
  padding: 3rem 1rem;
  text-align: center;
}

.header-content {
  max-width: 800px;
  margin: 0 auto;
}

h1 {
  font-size: 2.5rem;
  font-weight: 600;
  margin-bottom: 0.5rem;
}

header p {
  font-size: 1.1rem;
  opacity: 0.9;
}

main {
  max-width: 800px;
  margin: -2rem auto 3rem;
  padding: 0 1rem;
}

.card {
  background: var(--background);
  border-radius: 12px;
  box-shadow: var(--card-shadow);
  padding: 2rem;
}

.input-group {
  display: flex;
  gap: 1rem;
  margin-bottom: 1rem;
}

input {
  flex: 1;
  padding: 1rem;
  font-size: 1rem;
  border: 1px solid #dee2e6;
  border-radius: 8px;
  transition: var(--transition);
}

input:focus {
  outline: none;
  border-color: var(--primary);
  box-shadow: 0 0 0 3px rgba(67, 97, 238, 0.2);
}

button {
  transition: var(--transition);
  cursor: pointer;
  font-weight: 500;
  border-radius: 8px;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
}

.primary-button {
  padding: 1rem 2rem;
  background: var(--primary);
  color: white;
  border: none;
  font-size: 1rem;
}

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

.secondary-button {
  padding: 0.75rem 1.5rem;
  background: var(--secondary);
  color: var(--text);
  border: 1px solid #dee2e6;
  font-size: 0.9rem;
}

.secondary-button:hover {
  background: #e9ecef;
}

#output-section {
  margin-top: 2rem;
  animation: fadeIn 0.3s ease;
}

.output-container {
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

textarea {
  width: 100%;
  min-height: 300px;
  padding: 1.5rem;
  border: 1px solid #dee2e6;
  border-radius: 8px;
  font-family: inherit;
  font-size: 1rem;
  line-height: 1.6;
  resize: vertical;
  transition: var(--transition);
}

textarea:focus {
  outline: none;
  border-color: var(--primary);
}

.output-actions {
  display: flex;
  gap: 1rem;
  justify-content: flex-end;
}

.hidden {
  display: none;
}

.spinner {
  width: 20px;
  height: 20px;
  border: 3px solid rgba(255, 255, 255, 0.3);
  border-radius: 50%;
  border-top-color: white;
  animation: spin 1s ease-in-out infinite;
}

@keyframes spin {
  to { transform: rotate(360deg); }
}

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

@media (max-width: 600px) {
  .input-group {
    flex-direction: column;
  }
  
  button {
    width: 100%;
  }
}