:root {
  --accent: #1565c0;
  --border: #d0d7de;
  --code-bg: #f6f8fa;
  --text: #1f2328;
  --muted: #57606a;
}
* { box-sizing: border-box; }
body {
  font-family: "Segoe UI", Tahoma, Arial, sans-serif;
  color: var(--text);
  line-height: 1.55;
  max-width: 900px;
  margin: 0 auto;
  padding: 20px 24px 60px;
}
h1 {
  border-bottom: 2px solid var(--accent);
  padding-bottom: 8px;
  margin-top: 8px;
}
h2 {
  margin-top: 40px;
  padding-top: 12px;
  border-top: 1px solid var(--border);
}
h3 { margin-top: 24px; }
a { color: var(--accent); text-decoration: none; }
a:hover { text-decoration: underline; }
code {
  font-family: Consolas, "Courier New", monospace;
  background: var(--code-bg);
  border: 1px solid var(--border);
  border-radius: 3px;
  padding: 1px 5px;
  font-size: 0.92em;
}
pre {
  font-family: Consolas, "Courier New", monospace;
  background: var(--code-bg);
  border: 1px solid var(--border);
  border-radius: 6px;
  padding: 12px 14px;
  overflow-x: auto;
  font-size: 0.92em;
  line-height: 1.4;
}
pre code {
  background: none;
  border: none;
  padding: 0;
  font-size: 1em;
}
table {
  border-collapse: collapse;
  width: 100%;
  margin: 12px 0;
}
th, td {
  border: 1px solid var(--border);
  padding: 6px 10px;
  text-align: left;
  vertical-align: top;
}
th { background: var(--code-bg); font-weight: 600; }
kbd {
  font-family: Consolas, "Courier New", monospace;
  background: var(--code-bg);
  border: 1px solid var(--border);
  border-bottom-width: 2px;
  border-radius: 3px;
  padding: 1px 6px;
  font-size: 0.9em;
}
.note {
  background: #fff8e6;
  border: 1px solid #e0c368;
  border-radius: 6px;
  padding: 10px 14px;
  margin: 14px 0;
}
.warn {
  background: #fdecea;
  border: 1px solid #e09692;
  border-radius: 6px;
  padding: 10px 14px;
  margin: 14px 0;
}
.toc { background: var(--code-bg); border: 1px solid var(--border); border-radius: 6px; padding: 12px 16px 12px 36px; }
.topnav {
  background: var(--code-bg);
  border: 1px solid var(--border);
  border-radius: 6px;
  padding: 8px 14px;
  margin-bottom: 20px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 8px 18px;
}
.topnav .pages a {
  margin-right: 16px;
  font-weight: 600;
}
.topnav .pages a:last-child { margin-right: 0; }
.topnav .pages a.current { color: var(--text); }
.brand {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  text-decoration: none;
}
.brand svg {
  width: 30px;
  height: 30px;
  display: block;
  transition: transform 0.15s;
}
.brand:hover { text-decoration: none; }
.brand:hover svg { transform: scale(1.06); }
.brand span {
  font-size: 1.05rem;
  font-weight: 800;
  letter-spacing: 0.08em;
  background: linear-gradient(90deg, #22d3ee, #3b82f6);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
}
.banner {
  text-align: center;
  margin: 0 0 22px;
}
.banner img {
  width: 100%;
  height: auto;
  display: block;
  border: 1px solid var(--border);
  border-radius: 10px;
  box-shadow: 0 4px 18px rgba(0, 0, 0, .14);
}
.side-nav {
  position: fixed;
  left: 16px;
  top: 24px;
  width: 210px;
  background: var(--code-bg);
  border: 1px solid var(--border);
  border-radius: 6px;
  padding: 10px 12px;
  font-size: 0.85em;
  max-height: calc(100vh - 48px);
  overflow-y: auto;
  z-index: 10;
}
.side-nav ol { margin: 0; padding-left: 18px; }
.side-nav li { margin: 3px 0; }
.side-nav a.current { color: var(--accent); font-weight: 600; }
#toTop {
  position: fixed;
  right: 20px;
  bottom: 20px;
  width: 44px;
  height: 44px;
  border: none;
  border-radius: 50%;
  background: var(--accent);
  color: #fff;
  font-size: 20px;
  line-height: 1;
  cursor: pointer;
  z-index: 10;
  display: none;
  box-shadow: 0 2px 8px rgba(0, 0, 0, .25);
}
#toTop:hover { background: #0d47a1; }
@media (max-width: 1250px) { .side-nav { display: none; } }
summary { cursor: pointer; }