/* 主站中英双语（默认英文，右上角「中」按钮切换） */
.lang-zh { display: none; }
html[data-lang="zh"] .lang-en { display: none; }
html[data-lang="zh"] .lang-zh { display: revert; }

#langBtn {
  border: 1px solid #e5e7eb; background: #fff; border-radius: 999px;
  padding: 4px 12px; font-size: 12px; line-height: 1.6; cursor: pointer;
  color: #374151; font-family: inherit; margin: 0 6px;
}
#langBtn:hover { border-color: #7c9cff; color: #2563eb; }

/* 姐妹站（友情链接） */
.sisters {
  background: #fbfcfe; border-top: 1px solid #e5e7eb; margin-top: 30px; padding: 16px 20px;
}
.sisters .sisters-inner { display: flex; flex-wrap: wrap; gap: 18px; align-items: center; font-size: 13.5px; }
.sisters b { color: #6b7280; font-weight: 600; font-size: 13px; margin-right: 4px; }
.sisters a { color: #374151; }
.sisters a:hover { color: #2563eb; }