/* =========================
   Base typography & layout
   ========================= */

html {
  font-size: 16px;
}

body {
  margin: 0;
  padding: 0;
  color: #111;
  background: #fff;
  font-family: system-ui, -apple-system, BlinkMacSystemFont,
               "Segoe UI", Roboto, Helvetica, Arial,
               "Noto Sans", "PingFang SC", "Hiragino Sans GB",
               "Microsoft YaHei", sans-serif;
  line-height: 1.7;
}

/* =========================
   Reading container
   ========================= */

article {
  max-width: 68ch;          /* 字符宽度，而不是像素宽度 */
  margin: 4rem auto;
  padding: 0 1.25rem;
}

/* =========================
   Headings
   ========================= */

article h1,
article h2,
article h3 {
  line-height: 1.35;
  font-weight: 600;
}

article h1 {
  font-size: 1.6rem;
  margin: 3rem 0 1.5rem;
}

article h2 {
  font-size: 1.25rem;
  margin: 2.5rem 0 1.2rem;
}

article h3 {
  font-size: 1.1rem;
  margin: 2rem 0 1rem;
}

/* =========================
   Paragraphs & lists
   ========================= */

article p {
  margin: 1.2rem 0;
}

article ul,
article ol {
  margin: 1.2rem 0 1.2rem 1.5rem;
}

article li {
  margin: 0.4rem 0;
}

/* =========================
   Blockquotes
   ========================= */

article blockquote {
  margin: 2rem 0;
  padding-left: 1rem;
  border-left: 3px solid #ddd;
  color: #555;
}

/* =========================
   Images (book-style)
   ========================= */

article img {
  display: block;
  max-width: 85%;
  height: auto;
  margin: 2rem auto;
}

/* Optional: subtle material feeling */
article img {
  border-radius: 2px;
}

/* =========================
   Horizontal rules
   ========================= */

article hr {
  border: none;
  border-top: 1px solid #eee;
  margin: 3rem 0;
}

/* =========================
   Links
   ========================= */

a {
  color: #0044cc;
  text-decoration: none;
}

a:hover {
  text-decoration: underline;
}

/* =========================
   Tables (minimal)
   ========================= */

article table {
  border-collapse: collapse;
  margin: 2rem auto;
  max-width: 100%;
}

article th,
article td {
  padding: 0.5rem 0.75rem;
  border-bottom: 1px solid #ddd;
  text-align: left;
}

article th {
  font-weight: 600;
}