*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "Helvetica Neue",
               "PingFang SC", "Microsoft YaHei", sans-serif;
  background: linear-gradient(180deg, #f7fbff 0, #f3f7fc 260px, #f6f8fb 100%);
  color: #1f2d3d;
  line-height: 1.82;
}

#nav-mount { min-height: 76px; background: #fff; }

.page-wrap {
  width: min(900px, calc(100vw - 32px));
  margin: 0 auto;
  padding: 28px 0 68px;
}

main {
  background: #fff;
  border: 1px solid #d8e2ef;
  border-radius: 8px;
  box-shadow: 0 8px 24px rgba(31, 56, 88, 0.08);
  padding: 30px;
}

article h1, article h2, article h3, article h4 {
  margin: 1.55em 0 0.62em;
  line-height: 1.35;
  color: #0f1f33;
  letter-spacing: 0;
}
article h1 {
  font-size: clamp(28px, 4.8vw, 42px);
  margin-top: 0;
  padding-bottom: 14px;
  border-bottom: 1px solid #e8eef6;
}
article h2 {
  font-size: 1.45em;
  padding-bottom: 7px;
  border-bottom: 1px solid #e8eef6;
}
article h2::before {
  content: "";
  display: inline-block;
  width: 4px;
  height: 18px;
  margin-right: 9px;
  border-radius: 2px;
  vertical-align: -2px;
  background: #006eff;
}
article h3 { font-size: 1.16em; }

article p { margin: 0.82em 0; }

article img { display: block; max-width: 100%; height: auto; }
article .arithmatex,
article mjx-container[display="true"] {
  max-width: 100%;
  overflow-x: auto;
  overflow-y: hidden;
}

article ul, article ol {
  padding-left: 1.55em;
  margin: 0.72em 0;
}
article li { margin: 0.34em 0; }

article blockquote {
  border-left: 4px solid #006eff;
  padding: 9px 16px;
  color: #26405f;
  margin: 1em 0;
  background: #f4f9ff;
  border-radius: 0 8px 8px 0;
}

article code {
  background: #eef4fb;
  color: #0f356d;
  padding: 1px 6px;
  border-radius: 4px;
  font-size: 0.9em;
  font-family: "SFMono-Regular", Consolas, monospace;
}

article pre {
  background: #f8fbff;
  border: 1px solid #d8e2ef;
  border-radius: 8px;
  padding: 16px;
  overflow-x: auto;
  margin: 1em 0;
}
article pre code { background: none; padding: 0; color: inherit; }

article table {
  border-collapse: collapse;
  width: 100%;
  margin: 1.1em 0;
  font-size: 0.95em;
  background: #fff;
}
article th, article td {
  border: 1px solid #e0e8f2;
  padding: 9px 12px;
  text-align: left;
}
article th { background: #f2f7ff; color: #24364f; font-weight: 720; }
article tr:nth-child(even) td { background: #fbfdff; }

article hr { border: none; border-top: 1px solid #e8eef6; margin: 2em 0; }

article a { color: #0052d9; text-decoration: none; }
article a:hover { color: #006eff; text-decoration: underline; }

.footnote {
  font-size: 0.85em;
  color: #5f6f85;
  margin-top: 3em;
  border-top: 1px solid #e8eef6;
  padding-top: 1em;
}

h1 { color: #0f1f33; font-size: clamp(28px, 4.8vw, 40px); margin-bottom: 24px; letter-spacing: 0; }

.article-list {
  list-style: none;
  padding: 0;
  border: 1px solid #d8e2ef;
  border-radius: 8px;
  overflow: hidden;
  background: #fff;
}
.article-list li {
  border-bottom: 1px solid #e8eef6;
}
.article-list li:last-child { border-bottom: 0; }
.article-list a {
  display: block;
  padding: 15px 18px;
  color: #0f1f33;
  text-decoration: none;
  font-size: 1.02em;
  transition: background 0.16s ease, color 0.16s ease, transform 0.16s ease;
}
.article-list a:hover {
  color: #0052d9;
  background: #f4f9ff;
  transform: translateX(2px);
}

footer {
  margin-top: 18px;
  padding: 18px 20px;
  border: 1px solid #d8e2ef;
  border-radius: 8px;
  background: #eef4fb;
  font-size: 0.92em;
}
footer a { color: #44556b; text-decoration: none; }
footer a:hover { color: #0052d9; }

@media (max-width: 640px) {
  .page-wrap { width: min(100vw - 24px, 760px); padding: 18px 0 44px; }
  main { padding: 20px; }
}