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

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  background: #0d1117;
  color: #c9d1d9;
  line-height: 1.7;
}

/* ── Landing Page ── */
.landing {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  padding: 3rem 1.5rem;
}

.landing h1 {
  font-size: 2.2rem;
  color: #58a6ff;
  margin-bottom: 0.3rem;
  text-align: center;
}

.landing .subtitle {
  color: #8b949e;
  font-size: 1rem;
  margin-bottom: 3rem;
  text-align: center;
}

.guide-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(340px, 1fr));
  gap: 1.5rem;
  max-width: 900px;
  width: 100%;
}

.guide-card {
  background: #161b22;
  border: 1px solid #30363d;
  border-radius: 12px;
  padding: 1.8rem;
  text-decoration: none;
  color: inherit;
  transition: border-color 0.2s, transform 0.15s, box-shadow 0.2s;
}

.guide-card:hover {
  border-color: #58a6ff;
  transform: translateY(-2px);
  box-shadow: 0 8px 24px rgba(0, 0, 0, 0.4);
}

.guide-card .icon {
  font-size: 2rem;
  margin-bottom: 0.8rem;
}

.guide-card h2 {
  color: #58a6ff;
  font-size: 1.2rem;
  margin-bottom: 0.5rem;
}

.guide-card p {
  color: #8b949e;
  font-size: 0.9rem;
  line-height: 1.5;
}

.guide-card .tag {
  display: inline-block;
  margin-top: 1rem;
  font-size: 0.75rem;
  color: #58a6ff;
  background: rgba(88, 166, 255, 0.1);
  padding: 0.2rem 0.6rem;
  border-radius: 999px;
}

.footer {
  margin-top: 4rem;
  text-align: center;
}

.footer-logo {
  height: 40px;
  width: auto;
  opacity: 0.5;
  transition: opacity 0.2s;
}

.footer-logo:hover {
  opacity: 0.7;
}

/* ── Guide Pages ── */
.guide-page {
  max-width: 900px;
  margin: 0 auto;
  padding: 2rem 1.5rem 4rem;
}

.guide-page .back {
  display: inline-block;
  color: #58a6ff;
  text-decoration: none;
  font-size: 0.9rem;
  margin-bottom: 1.5rem;
}

.guide-page .back:hover { text-decoration: underline; }

#content h1 { color: #58a6ff; border-bottom: 1px solid #30363d; padding-bottom: 0.5rem; margin-bottom: 1rem; }
#content h2 { color: #58a6ff; margin-top: 2.5rem; border-bottom: 1px solid #21262d; padding-bottom: 0.3rem; }
#content h3 { color: #79c0ff; margin-top: 1.5rem; }
#content h4 { color: #a5d6ff; margin-top: 1.2rem; }
#content a { color: #58a6ff; text-decoration: none; }
#content a:hover { text-decoration: underline; }

#content code {
  background: #161b22;
  padding: 0.15em 0.4em;
  border-radius: 4px;
  font-size: 0.9em;
  font-family: 'SF Mono', 'Fira Code', monospace;
}

#content pre {
  background: #161b22;
  border: 1px solid #30363d;
  border-radius: 8px;
  padding: 1rem;
  overflow-x: auto;
  margin: 1rem 0;
}

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

#content blockquote {
  border-left: 4px solid #58a6ff;
  margin: 1rem 0;
  padding: 0.5rem 1rem;
  background: #161b22;
  border-radius: 0 6px 6px 0;
}

#content table { border-collapse: collapse; width: 100%; margin: 1rem 0; }
#content th, #content td { border: 1px solid #30363d; padding: 0.5rem 0.75rem; text-align: left; }
#content th { background: #161b22; color: #58a6ff; }
#content tr:nth-child(even) { background: #0d1117; }
#content tr:nth-child(odd) { background: #161b22; }
#content hr { border: none; border-top: 1px solid #30363d; margin: 2rem 0; }
#content ul, #content ol { padding-left: 1.5rem; margin: 0.5rem 0; }
#content li { margin: 0.3rem 0; }
#content strong { color: #e6edf3; }
#content img { max-width: 100%; border-radius: 8px; }
#content p { margin: 0.6rem 0; }

@media (max-width: 600px) {
  .landing h1 { font-size: 1.6rem; }
  .guide-grid { grid-template-columns: 1fr; }
  .guide-page { padding: 1rem; }
  #content pre { font-size: 0.85em; }
}