/* 全站共用的字体与排版尺度：采用 ChatGPT 当前公开页面的默认系统字体栈。 */
:root {
  --font-ui: "-apple-system-body", "ui-sans-serif", "-apple-system", "system-ui", "Segoe UI", "Helvetica", "Apple Color Emoji", "Arial", "sans-serif", "Segoe UI Emoji", "Segoe UI Symbol";
  --font-code: "ui-monospace", "SFMono-Regular", "SF Mono", "Menlo", "Consolas", "Liberation Mono", "monospace";
  --type-display: 2rem;
  --type-title: 1.375rem;
  --type-heading: 1.125rem;
  --type-body: 1rem;
  --type-chat: var(--type-ui);
  --type-ui: .875rem;
  --type-label: .8125rem;
  --type-meta: .75rem;
  --weight-regular: 400;
  --weight-medium: 500;
  --weight-semibold: 600;
  --leading-body: 1.8;
  --leading-chat: 1.625;
  --leading-ui: 1.5;
  --leading-heading: 1.35;
}

body {
  font-family: var(--font-ui);
  font-size: var(--type-body);
  font-weight: var(--weight-regular);
  line-height: var(--leading-body);
  font-synthesis: style;
  -webkit-font-smoothing: antialiased;
}
button, input, textarea, select { font-family: inherit; }
h1, h2, h3, h4, h5, h6 {
  font-weight: var(--weight-semibold);
  line-height: var(--leading-heading);
  letter-spacing: -.02em;
  text-wrap: balance;
}
strong, b { font-weight: var(--weight-semibold); }
code, pre, kbd, samp { font-family: var(--font-code); }