:root { color-scheme: light; }
* { box-sizing: border-box; }
body {
  margin: 0;
  font: 16px/1.75 -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC",
    "Hiragino Sans GB", "Noto Sans SC", sans-serif;
  color: #1c1c1c;
  background: #f4f5f7;
}
article {
  max-width: 42rem;
  margin: 0 auto;
  padding: 1.75rem 1.25rem 3rem;
  background: #fff;
  min-height: 100vh;
}
h1 { font-size: 1.45rem; line-height: 1.35; margin: 0 0 0.5rem; }
.meta { color: #666; font-size: 0.875rem; margin: 0 0 1.5rem; }
h2 { font-size: 1.05rem; margin: 1.6rem 0 0.5rem; }
h3 { font-size: 0.98rem; margin: 1.25rem 0 0.4rem; }
p, li { margin: 0.45rem 0; }
ul, ol { padding-left: 1.25rem; }
strong { font-weight: 600; }
code {
  font-size: 0.9em;
  background: #f3f4f6;
  padding: 0.05em 0.3em;
  border-radius: 3px;
}
.table-wrap { overflow-x: auto; margin: 0.75rem 0 1rem; -webkit-overflow-scrolling: touch; }
table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.875rem;
  line-height: 1.5;
}
th, td {
  border: 1px solid #e8eaed;
  padding: 0.45rem 0.55rem;
  text-align: left;
  vertical-align: top;
}
th { background: #f7f8fa; font-weight: 600; }
.operator { margin-top: 2rem; padding-top: 1rem; border-top: 1px solid #eee; font-size: 0.9rem; color: #444; }