/* 自然中文排版：正文以系统中文无衬线呈现，标题使用轻度宋体质感。 */
body {
  font-family: "PingFang SC", "MiSans", "HarmonyOS Sans SC", "Microsoft YaHei", "Noto Sans SC", Arial, sans-serif;
  letter-spacing: .015em;
}

h1,
h2 {
  font-family: "Noto Serif SC", "Songti SC", STSong, SimSun, serif;
  font-weight: 700;
  letter-spacing: .055em;
  line-height: 1.12;
}

.hero-copy h1 {
  font-size: clamp(62px, 6.2vw, 92px);
  letter-spacing: .02em;
  line-height: 1.12;
}

.hero-title-line {
  display: block;
  white-space: nowrap;
}
.section-heading h2 { letter-spacing: .04em; }
.threshold-card h3,
.protocol-flow h3 {
  font-family: "PingFang SC", "MiSans", "HarmonyOS Sans SC", "Microsoft YaHei", "Noto Sans SC", Arial, sans-serif;
  letter-spacing: .025em;
  font-weight: 700;
}

.brand,
nav,
.button,
.action-title,
.legacy-grid h3 {
  font-family: "PingFang SC", "MiSans", "HarmonyOS Sans SC", "Microsoft YaHei", "Noto Sans SC", Arial, sans-serif;
}

.lede,
.section-heading > p,
.protocol-flow p,
.legacy-grid p,
.threshold-meter p,
.microcopy { line-height: 1.82; }