* {
  box-sizing: border-box;
}

body {
  margin: 0;
  font-family: system-ui, -apple-system, BlinkMacSystemFont, 'Segoe UI',
    sans-serif;
  background: #0b1120;
  color: #f8fafc;
  line-height: 1.6;
}

.container {
  max-width: 768px;
  margin: 0 auto;
  padding: 2.5rem 1.5rem 4rem;
}

header {
  margin-bottom: 2rem;
  text-align: center;
}

header h1 {
  margin: 0 0 0.5rem;
  font-size: clamp(1.75rem, 4vw, 2.75rem);
}

header p {
  margin: 0;
  color: #cbd5f5;
}

.markdown h2,
.markdown h3,
.markdown h4 {
  margin-top: 2.5rem;
  margin-bottom: 1rem;
  line-height: 1.3;
}

.markdown h2 {
  font-size: 1.75rem;
}

.markdown h3 {
  font-size: 1.4rem;
}

.markdown p {
  margin: 1rem 0;
}

.markdown code {
  font-family: 'Fira Code', 'SFMono-Regular', Menlo, Monaco, Consolas,
    'Liberation Mono', Courier, monospace;
  background: rgba(15, 23, 42, 0.7);
  padding: 0.125rem 0.375rem;
  border-radius: 4px;
  color: #e2e8f0;
}

.markdown pre {
  background: rgba(15, 23, 42, 0.7);
  padding: 1rem;
  border-radius: 8px;
  overflow-x: auto;
}

.markdown a {
  color: #60a5fa;
  text-decoration: none;
}

.markdown a:hover,
.markdown a:focus {
  text-decoration: underline;
}

.error {
  margin-top: 2rem;
  padding: 1rem;
  border-radius: 8px;
  background: rgba(239, 68, 68, 0.15);
  color: #fca5a5;
  font-weight: 600;
}