/* 顶部导航栏（深色背景 / 白色文字 / 当前页高亮） */
.topnav {
  position: sticky;
  top: 0;
  z-index: 100;
  display: flex;
  align-items: center;
  gap: 24px;
  background: #111114;
  color: #e8e8ef;
  padding: 0 18px;
  height: 40px;
  font-size: 13px;
}
.topnav .brand {
  font-weight: 800;
  font-size: 15px;
  color: #fff;
  text-decoration: none;
  letter-spacing: 1px;
  flex-shrink: 0;
  display: flex;
  align-items: center;
  gap: 8px;
}
.topnav .brand .brand-logo {
  height: 34px;
  width: auto;
  object-fit: contain;
  border-radius: 4px;
  display: block;
}
.topnav .links {
  display: flex;
  gap: 4px;
  flex: 1;
  overflow-x: auto;
}
.topnav .links a {
  color: #9a9aa5;
  text-decoration: none;
  padding: 5px 12px;
  border-radius: 5px;
  font-weight: 500;
  white-space: nowrap;
}
.topnav .links a:hover {
  color: #fff;
  background: #2a2a30;
}
.topnav .links a.active {
  color: #fff;
  background: #2a6df2;
}