@font-face {
  font-family: 'Source Han Sans';
  src: url('../fonts/source-han-sans-cn-site.woff2?v=20261009-zh93') format('woff2');
  font-style: normal;
  font-weight: 250 900;
  font-display: swap;
  unicode-range: U+2000-206F, U+3000-303F, U+3400-9FFF, U+FF00-FFEF;
}

:root[lang='zh-CN'] { --ff-poppins: 'Poppins', 'Source Han Sans', 'PingFang SC', 'Microsoft YaHei', sans-serif; }
:root[lang='zh-CN'] body { font-family: var(--ff-poppins); }
:root[lang='zh-CN'] .navbar-link { font-weight: 500; letter-spacing: .02em; }
:root[lang='zh-CN'] .about-text p,
:root[lang='zh-CN'] .research-intro,
:root[lang='zh-CN'] .paper-detail-body p,
:root[lang='zh-CN'] .paper-body p,
:root[lang='zh-CN'] .pub-abstract p,
:root[lang='zh-CN'] .lesson-section p,
:root[lang='zh-CN'] .lesson-section li { line-height: 1.85; font-weight: 400; }
:root[lang='zh-CN'] .text-overlay h2 { max-width: 26ch; }

[data-language-control] {
  display: inline-grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  align-items: center;
  gap: 2px;
  width: 80px;
  height: 36px;
  padding: 3px;
  border: 1px solid var(--jet);
  border-radius: 11px;
  background: var(--theme-surface);
  box-shadow: none;
}
[data-language-control] button {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 100%;
  min-width: 0;
  height: 28px;
  padding: 0;
  border-radius: 7px;
  font-family: var(--ff-poppins);
  font-size: 11px;
  font-weight: 500;
  line-height: 1;
  text-align: center;
  color: var(--theme-body);
  cursor: pointer;
  transition: background-color .15s, color .15s;
}
[data-language-control] button[aria-pressed='true'] {
  background: rgba(var(--theme-accent-rgb), .14);
  color: var(--theme-accent);
}
[data-language-control] button:hover { background: rgba(var(--theme-accent-rgb), .08); }
[data-language-control] button:focus-visible { outline: 2px solid var(--theme-accent); outline-offset: 2px; }
.language-status { position: absolute; width: 1px; height: 1px; padding: 0; overflow: hidden; clip-path: inset(50%); white-space: nowrap; }

:root[lang='zh-CN'] .tutorial-reader .lesson-section p,
:root[lang='zh-CN'] .pub-abstract p,
:root[lang='zh-CN'] .about-text .skills-list > p { font-size: 16px; }

@media (min-width: 1024px) {
  .desktop-nav-anchor .navbar { grid-template-columns: 130px minmax(0, 1fr) 130px; }
  .navbar-language-slot[data-language-control] { flex: 0 0 auto; height: 36px; }
  :root[lang='zh-CN'] .tutorial-reader .lesson-section p,
  :root[lang='zh-CN'] .pub-abstract p { font-size: 17px; }
  :root[lang='zh-CN'] .about-text .skills-list > p { font-size: 18px; }
}
@media (max-width: 1023px) {
  [data-language-control] {
    position: absolute;
    top: 8px;
    left: 44px;
    z-index: 6;
    width: 72px;
    height: 28px;
    padding: 2px;
    border-radius: 9px;
  }
  [data-language-control] button { height: 22px; border-radius: 6px; }
  :root[lang='zh-CN'] .navbar .navbar-link { font-size: clamp(13px, 3.5vw, 15px); padding-inline: 5px; }
}