:root {
  --bg-color: #fafafa;
  --text-color: #333;
  --code-bg: #f4f4f4;
  --link-color: #0969da;
  --header-color: #24292f;
  --border-color: #d0d7de;
}

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

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Helvetica, Arial, sans-serif;
  line-height: 1.6;
  color: var(--text-color);
  background: 
    linear-gradient(rgba(255,255,255,0.9), rgba(255,255,255,0.9)),
    url('bg-main.jpg');
  background-size: cover;
  background-attachment: fixed;
  padding: 2rem;
}

.container {
  max-width: 800px;
  margin: 0 auto;
  background: white;
  padding: 2rem 3rem;
  border-radius: 8px;
  box-shadow: 0 1px 3px rgba(0,0,0,0.1);
}

h1 {
  color: var(--header-color);
  font-size: 2rem;
  margin-bottom: 1.5rem;
  padding-bottom: 0.5rem;
  border-bottom: 1px solid var(--border-color);
}

h2 {
  color: var(--header-color);
  font-size: 1.5rem;
  margin: 2rem 0 1rem;
}

h3 {
  color: var(--header-color);
  font-size: 1.1rem;
  margin: 1.5rem 0 0.5rem;
}

p {
  margin: 0.5rem 0;
}

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

a:hover {
  text-decoration: underline;
}

code {
  background: var(--code-bg);
  padding: 0.2rem 0.4rem;
  border-radius: 4px;
  font-size: 0.9em;
  font-family: ui-monospace, SFMono-Regular, SF Mono, Menlo, Consolas, monospace;
}

pre {
  background: var(--code-bg);
  padding: 1rem;
  border-radius: 6px;
  overflow-x: auto;
  margin: 0.5rem 0 1rem;
}

pre code {
  background: none;
  padding: 0;
}

ul, ol {
  margin: 0.5rem 0 1rem 1.5rem;
}

li {
  margin: 0.25rem 0;
}

section {
  margin-bottom: 1rem;
}

.back-link {
  margin-top: 2rem;
  padding-top: 1rem;
  border-top: 1px solid var(--border-color);
  text-align: center;
}

.back-link a {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 10px 20px;
  background: #24292f;
  color: white;
  border-radius: 6px;
  font-size: 14px;
}

.back-link a:hover {
  background: #444c56;
  text-decoration: none;
}

@media (max-width: 600px) {
  body {
    padding: 1rem;
  }
  .container {
    padding: 1.5rem;
  }
}