/* Material World Angular Square M Logo v4 (思源黑体精修版) */
.site-header .header-inner { height: 84px; gap: 24px; }
.site-header .brand { display: block; width: 216px; flex: 0 0 216px; line-height: 0; }
.site-header .brand picture { display: block; }
.site-header .brand img { display: block; width: 100%; height: auto; max-height: 52px; object-fit: contain; }
@media (max-width: 1200px) {
  .site-header .header-inner { gap: 18px; }
  .site-header .brand { width: 196px; flex-basis: 196px; }
  .site-header .brand img { max-height: 48px; }
}
@media (max-width: 950px) {
  .site-header .header-inner { height: 76px; }
  .site-header .brand { width: 176px; flex-basis: 176px; }
  .site-header .brand img { max-height: 44px; }
  .site-header .nav { top: 100%; }
}
@media (max-width: 760px) {
  .site-header .header-inner { height: 70px; gap: 12px; }
  .site-header .brand { width: 156px; flex-basis: 156px; }
  .site-header .brand img { max-height: 38px; }
  .site-header .nav { top: 70px; }
}
@media (max-width: 360px) {
  .site-header .brand { width: 138px; flex-basis: 138px; }
  .site-header .brand img { max-height: 34px; }
  .site-header .header-tools { gap: 6px; }
}