:root {
  --fg: #0f172a; /* slate-900 */
  --muted: #64748b; /* slate-600 */
  --bg: #ffffff;
}
* {
  box-sizing: border-box;
}
body {
  margin: 0;
  background: var(--bg);
  color: var(--fg);
  font-family: system-ui, -apple-system, 'Segoe UI', Roboto, 'PingFang SC',
    'Microsoft YaHei', Arial, sans-serif;
}
.page {
  max-width: 880px;
  padding: 24px 16px 40px;
  /* 不居中：自然从页面顶部开始，左对齐 */
  margin: 0; /* no horizontal centering */
}
.title {
  margin: 8px 16px 6px 16px;
  font-size: clamp(1.05rem, 1rem + 0.8vw, 1.4rem);
  font-weight: 650;
}
.subtitle {
  margin: 0 16px 16px 16px;
  color: var(--muted);
  line-height: 1.7;
  font-size: clamp(0.95rem, 0.92rem + 0.25vw, 1rem);
  max-width: 64ch;
}
#errorMessage {
  margin: 16px 24px;
  color: red;
}
.cap-wrap {
  margin: 12px 16px 0 16px;
}
#cap {
  width: min(360px, 92vw);
}
@media (min-width: 1024px) {
  .page {
    padding-left: 32px;
  }
  .title,
  .subtitle,
  .cap-wrap {
    margin-left: 24px;
  }
}