* {
  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: 40px;
  padding: 20px;
}

header h1 {
  font-size: 2.5rem;
  margin-bottom: 10px;
  font-weight: 700;
}

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

main {
  background: white;
  border-radius: 12px;
  padding: 40px;
  box-shadow: 0 10px 40px rgba(0, 0, 0, 0.2);
}

/* Loading state */
.loading {
  text-align: center;
  padding: 40px;
  font-size: 1.2rem;
  color: #667eea;
}

/* Error state */
.error {
  background-color: #fee;
  border: 1px solid #fcc;
  border-radius: 8px;
  padding: 20px;
  margin-bottom: 20px;
}

.error-message {
  color: #c00;
  font-weight: 500;
}

/* Success state */
.success {
  text-align: center;
  padding: 40px;
}

.success h2 {
  color: #10b981;
  font-size: 2rem;
  margin-bottom: 15px;
}

.success p {
  font-size: 1.1rem;
  color: #666;
  margin-bottom: 25px;
}

/* Sentences container */
.sentences-container {
  margin-bottom: 30px;
}

.sentence-item {
  margin-bottom: 30px;
  padding: 20px;
  background: #f8f9fa;
  border-radius: 8px;
  border-left: 4px solid #667eea;
  transition: transform 0.2s;
}

.sentence-item:hover {
  transform: translateX(4px);
}

.sentence-number {
  font-weight: 700;
  color: #667eea;
  margin-bottom: 8px;
  font-size: 0.9rem;
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

.sentence-text {
  font-size: 1.1rem;
  margin-bottom: 15px;
  color: #333;
  line-height: 1.6;
  padding: 10px;
  background: white;
  border-radius: 4px;
}

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

.translation-input {
  width: 100%;
  padding: 12px 15px;
  font-size: 1rem;
  border: 2px solid #ddd;
  border-radius: 6px;
  transition: border-color 0.3s;
  font-family: inherit;
}

.translation-input:focus {
  outline: none;
  border-color: #667eea;
  box-shadow: 0 0 0 3px rgba(102, 126, 234, 0.1);
}

.translation-input:valid {
  border-color: #10b981;
}

/* Form actions */
.form-actions {
  display: flex;
  gap: 15px;
  justify-content: center;
  padding-top: 20px;
  border-top: 2px solid #eee;
}

/* Buttons */
button {
  padding: 14px 32px;
  font-size: 1rem;
  font-weight: 600;
  border: none;
  border-radius: 8px;
  cursor: pointer;
  transition: all 0.3s;
  font-family: inherit;
}

.btn-submit {
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  color: white;
  box-shadow: 0 4px 15px rgba(102, 126, 234, 0.4);
}

.btn-submit:hover:not(:disabled) {
  transform: translateY(-2px);
  box-shadow: 0 6px 20px rgba(102, 126, 234, 0.5);
}

.btn-submit:disabled {
  background: #ccc;
  cursor: not-allowed;
  box-shadow: none;
}

.btn-secondary {
  background: white;
  color: #667eea;
  border: 2px solid #667eea;
}

.btn-secondary:hover {
  background: #f8f9fa;
  transform: translateY(-2px);
}

.btn-primary {
  background: #10b981;
  color: white;
  box-shadow: 0 4px 15px rgba(16, 185, 129, 0.3);
}

.btn-primary:hover {
  background: #059669;
  transform: translateY(-2px);
  box-shadow: 0 6px 20px rgba(16, 185, 129, 0.4);
}

/* Utility classes */
.hidden {
  display: none !important;
}

/* Responsive design */
@media (max-width: 768px) {
  header h1 {
    font-size: 2rem;
  }

  main {
    padding: 25px;
  }

  .form-actions {
    flex-direction: column;
  }

  button {
    width: 100%;
  }
}