:root {
  --font-sans: "Source Han Sans CN", "Noto Sans SC", "PingFang SC", "Microsoft YaHei", "微软雅黑", Arial, sans-serif;
}

html {
  font-size: clamp(16px, 1vw, 25.6px);
}

html,
body,
button,
input,
select,
textarea {
  font-family: var(--font-sans);
}

body {
  font-size: .875rem;
  line-height: 1.7;
  letter-spacing: .01em;
}

h1,
h2,
h3,
h4 {
  font-family: var(--font-sans);
  letter-spacing: -.015em;
}

.hero h1 { font-size: 3rem; line-height: 1.2; }
.hero p { font-size: .9375rem; line-height: 1.85; }
.section-title { font-size: 2rem; font-weight: 700; }
.feature-card h3 { font-size: 1.4rem; }
.feature-card p { font-size: .825rem; }

@media (max-width: 760px) {
  .hero h1 { font-size: 2rem; }
  .hero p { font-size: .875rem; }
  .section-title { font-size: 1.625rem; }
  .feature-card h3 { font-size: 1.15rem; }
}

                
#plans { scroll-margin-top: 16px; }