:root {
  --fg: hsl(230, 8%, 24%);
  --fg-muted: hsl(230, 4%, 64%);
  --bg: #ffffff;
  --border: hsl(230, 1%, 88%);
  --accent: hsl(221, 87%, 60%);
  --code-bg: hsl(230, 1%, 93%);
}

@media (prefers-color-scheme: dark) {
  :root {
    --fg: #abb2bf;
    --fg-muted: #5c6370;
    --bg: #21252b;
    --border: #3e4451;
    --accent: #61afef;
    --code-bg: #2c313a;
  }
}

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

body {
  font-family: 'Pretendard', -apple-system, BlinkMacSystemFont, sans-serif;
  background: var(--bg);
  color: var(--fg);
  line-height: 1.7;
  font-size: 16px;
}

.container {
  max-width: 720px;
  margin: 0 auto;
  padding: 3rem 2rem;
}

.back {
  font-family: 'JetBrains Mono', monospace;
  font-size: 0.85rem;
  color: var(--fg-muted);
  text-decoration: none;
  margin-bottom: 2rem;
  display: inline-block;
}

.back:hover {
  color: var(--accent);
}

header {
  margin-bottom: 3rem;
  border-bottom: 1px solid var(--border);
  padding-bottom: 2rem;
}

h1 {
  font-family: 'JetBrains Mono', monospace;
  font-size: 2.5rem;
  font-weight: 600;
  margin-bottom: 0.5rem;
  letter-spacing: -0.02em;
}

.subtitle {
  font-family: 'JetBrains Mono', monospace;
  color: var(--fg-muted);
  font-size: 0.9rem;
}

.version {
  display: inline-block;
  background: var(--code-bg);
  padding: 0.2rem 0.5rem;
  border-radius: 3px;
  font-family: 'JetBrains Mono', monospace;
  font-size: 0.75rem;
  margin-left: 0.5rem;
}

h2 {
  font-family: 'JetBrains Mono', monospace;
  font-size: 1.1rem;
  font-weight: 500;
  color: var(--fg-muted);
  margin-bottom: 1rem;
  margin-top: 3rem;
  text-transform: lowercase;
}

h2::before {
  content: '## ';
  opacity: 0.5;
}

p {
  margin-bottom: 1rem;
}

.highlight {
  background: linear-gradient(to bottom, transparent 60%, color-mix(in srgb, var(--accent) 20%, transparent) 60%);
}

blockquote {
  border-left: 2px solid var(--accent);
  padding-left: 1.5rem;
  margin: 1.5rem 0;
  font-style: italic;
  color: var(--fg-muted);
}

blockquote p {
  margin-bottom: 0;
}

ul {
  list-style: none;
  margin: 1rem 0;
}

ul li {
  position: relative;
  padding-left: 1.5rem;
  margin-bottom: 0.75rem;
}

ul li::before {
  content: '→';
  position: absolute;
  left: 0;
  color: var(--accent);
  font-family: 'JetBrains Mono', monospace;
}

pre {
  background: var(--code-bg);
  border: 1px solid var(--border);
  border-radius: 4px;
  padding: 1rem 1.5rem;
  font-family: 'JetBrains Mono', monospace;
  font-size: 0.9rem;
  margin: 1.5rem 0;
  overflow-x: auto;
  line-height: 1.6;
}

pre code {
  background: none;
  border: none;
  padding: 0;
  font-size: inherit;
}

code {
  display: inline-block;
  background: var(--code-bg);
  border: 1px solid var(--border);
  padding: 0.2rem 0.6rem;
  border-radius: 3px;
  font-family: 'JetBrains Mono', monospace;
  font-size: 0.8rem;
}

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

a:hover {
  text-decoration: underline;
}

hr {
  border: none;
  border-top: 1px solid var(--border);
  margin: 2rem 0;
}

footer {
  margin-top: 4rem;
  padding-top: 2rem;
  border-top: 1px solid var(--border);
  text-align: center;
  color: var(--fg-muted);
  font-size: 0.9rem;
}

@media (max-width: 600px) {
  .container {
    padding: 2rem 1.5rem;
  }

  h1 {
    font-size: 2rem;
  }
}