:root {
  --sans: 'DM Sans', 'PingFang SC', 'Microsoft YaHei', 'Noto Sans CJK SC', Arial, sans-serif;
  --mono: 'IBM Plex Mono', 'PingFang SC', 'Microsoft YaHei', monospace;
}

.hero h1 {
  font-size: clamp(2rem, 4vw, 3.7rem);
  line-height: 1.22;
  letter-spacing: -.025em;
}

.hero-description, .case-detail, .demo-note {
  line-height: 1.8;
}

h2 {
  line-height: 1.3;
  letter-spacing: -.025em;
}

@media (max-width: 900px) {
  .hero h1 { font-size: 3.5rem; }
}

@media (max-width: 550px) {
  .hero h1 { font-size: clamp(1.75rem, 9.3vw, 2.625rem); }
}