:root {
  --color-primary: #0066cc;
  --color-primary-hover: #0052a3;
  --color-error: #d32f2f;
  --color-success: #388e3c;
  --color-bg: #ffffff;
  --color-fg: #212121;
  --color-fg-muted: #666666;
  --color-border: #e0e0e0;
  --color-bg-alt: #f9f9f9;
  --color-bg-section: #f5f5f5;
  --color-bg-section-hover: #ebebeb;
  --color-error-bg: #ffebee;
  --color-button-text: #ffffff;
  --spacing: 1rem;
  --font-mono: 'Monaco', 'Courier New', monospace;
}

@media (prefers-color-scheme: dark) {
  :root {
    --color-primary: #3391ff;
    --color-primary-hover: #5ca7ff;
    --color-error: #ef5350;
    --color-success: #66bb6a;
    --color-bg: #1e1e1e;
    --color-fg: #e0e0e0;
    --color-fg-muted: #999999;
    --color-border: #404040;
    --color-bg-alt: #2a2a2a;
    --color-bg-section: #2a2a2a;
    --color-bg-section-hover: #333333;
    --color-error-bg: #3d1f1f;
    --color-button-text: #ffffff;
  }
}

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

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  line-height: 1.6;
  color: var(--color-fg);
  background: var(--color-bg);
  padding: var(--spacing);
}

header {
  text-align: center;
  margin-bottom: calc(var(--spacing) * 2);
}

h1 {
  color: var(--color-primary);
  margin-bottom: 0.5rem;
}

main {
  max-width: 1200px;
  margin: 0 auto;
  display: grid;
  gap: var(--spacing);
  grid-template-columns: 1fr;
}

@media (min-width: 768px) {
  main {
    grid-template-columns: 1fr 1fr;
  }

  .examples {
    grid-column: 1 / -1;
  }
}

section {
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}

label {
  font-weight: 600;
}

textarea {
  font-family: var(--font-mono);
  font-size: 14px;
  padding: 0.75rem;
  border: 2px solid var(--color-border);
  border-radius: 4px;
  resize: vertical;
  min-height: 200px;
  background: var(--color-bg);
  color: var(--color-fg);
}

textarea:focus {
  outline: 3px solid var(--color-primary);
  outline-offset: 2px;
  border-color: var(--color-primary);
}

textarea#output {
  background: var(--color-bg-alt);
}

.input-actions,
.output-actions {
  display: flex;
  gap: 0.5rem;
  flex-wrap: wrap;
}

button {
  padding: 0.5rem 1rem;
  border: 2px solid var(--color-primary);
  background: var(--color-bg);
  color: var(--color-primary);
  border-radius: 4px;
  cursor: pointer;
  font-size: 14px;
  font-weight: 600;
  transition: all 0.2s;
}

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

button:focus {
  outline: 3px solid var(--color-primary);
  outline-offset: 2px;
}

button:active {
  transform: translateY(1px);
}

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

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

.error {
  padding: 0.75rem;
  background: var(--color-error-bg);
  color: var(--color-error);
  border-left: 4px solid var(--color-error);
  border-radius: 4px;
  font-size: 14px;
  font-family: var(--font-mono);
}

.error.hidden {
  display: none;
}

.examples {
  margin-top: var(--spacing);
}

.examples summary {
  cursor: pointer;
  font-weight: 600;
  padding: 0.5rem;
  background: var(--color-bg-section);
  border-radius: 4px;
  user-select: none;
}

.examples summary:hover {
  background: var(--color-bg-section-hover);
}

.examples ul {
  list-style: none;
  padding: var(--spacing);
  display: grid;
  gap: 0.5rem;
}

@media (min-width: 768px) {
  .examples ul {
    grid-template-columns: 1fr 1fr;
  }
}

.examples li {
  display: flex;
}

.examples button {
  width: 100%;
  text-align: left;
  border: 1px solid var(--color-border);
  font-family: var(--font-mono);
  font-size: 13px;
  background: var(--color-bg);
  color: var(--color-fg);
  padding: 0.5rem;
}

.examples button:hover {
  background: var(--color-bg-section);
  color: var(--color-fg);
  border-color: var(--color-primary);
}

footer {
  text-align: center;
  margin-top: calc(var(--spacing) * 2);
  padding-top: var(--spacing);
  border-top: 1px solid var(--color-border);
  color: var(--color-fg-muted);
  font-size: 14px;
}

footer a {
  color: var(--color-primary);
  text-decoration: none;
}

footer a:hover {
  text-decoration: underline;
}

/* Print styles */
@media print {
  .input-actions,
  .output-actions,
  .examples,
  footer {
    display: none;
  }
}