:root {
  --text: #1f2937;
  --muted: #e5e7eb;
  --bg: #ffffff;
  --accent: #fddf00;
  --border: #e5e7eb;
}

html { 
  scroll-behavior: smooth; 
}

body { 
  font-family: system-ui, -apple-system, Segoe UI, Roboto, Ubuntu, Cantarell, Noto Sans, Helvetica, Arial, "Apple Color Emoji", "Segoe UI Emoji"; 
  color: var(--text); 
  background: var(--bg); 
  margin: 0; 
}

.container { 
  max-width: 880px; 
  margin: 0 auto; 
  padding: 24px; 
}

header { 
  padding: 16px 0 8px; 
}

h1 { 
  font-size: clamp(1.8rem, 1.2rem + 2vw, 2.4rem); 
  line-height: 1.15; 
  margin: 0 0 8px; 
}

.subtitle { 
  color: var(--muted); 
  margin: 0 0 24px; 
  font-size: 1rem; 
}

.toc { 
  border: 1px solid var(--border); 
  border-radius: 12px; 
  padding: 16px; 
  background: #fafafa; 
}

.toc h2 { 
  font-size: 1.05rem; 
  margin: 0 0 8px; 
}

.toc ul { 
  margin: 0; 
  padding-left: 18px; 
}

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

.toc a:hover { 
  text-decoration: underline; 
}

article h2 { 
  margin-top: 32px; 
  font-size: 1.5rem; 
}

article h3 { 
  margin-top: 20px; 
  font-size: 1.2rem; 
}

p { 
  line-height: 1.7; 
}

.tip { 
  border-left: 3px solid var(--accent); 
  padding: 8px 12px; 
  background: #e5e7eb; 
  border-radius: 8px; 
}

.cta-row { 
  display: grid; 
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr)); 
  gap: 12px; 
  margin: 16px 0; 
}

.cta { 
  border: 1px solid var(--border); 
  border-radius: 12px; 
  padding: 12px 14px; 
  background: #fff; 
}

.cta a { 
  display: inline-block; 
  margin-top: 8px; 
  text-decoration: none; 
  color: #fff; 
  background: var(--accent); 
  padding: 8px 12px; 
  border-radius: 8px; 
}

figure { 
  margin: 24px 0; 
}

figcaption { 
  color: var(--muted); 
  font-size: .9rem; 
}

footer { 
  margin-top: 40px; 
  padding-top: 16px; 
  border-top: 1px solid var(--border); 
  color: var(--muted); 
  font-size: .95rem; 
}