/* Shared theme controls for the two teaching experiments. */
html[data-theme="light"]{color-scheme:light}html[data-theme="dark"]{color-scheme:dark}
.visually-hidden{position:absolute;width:1px;height:1px;padding:0;margin:-1px;overflow:hidden;clip-path:inset(50%);white-space:nowrap;border:0}
.header-tools{display:flex;align-items:center;gap:14px}.theme-control{position:relative;display:block;width:116px;flex-shrink:0;color:var(--ink);font-size:12px}
.theme-control .theme-icon{position:absolute;left:9px;top:50%;transform:translateY(-50%);width:16px;height:16px;pointer-events:none}
.theme-control select{appearance:none;-webkit-appearance:none;width:100%;min-height:44px;padding:9px 20px 9px 30px;background:var(--paper);color:var(--ink);border:1px solid var(--line);border-radius:6px;font:inherit;cursor:pointer}
.theme-control:after{content:"";position:absolute;right:9px;top:50%;width:5px;height:5px;border-right:1.5px solid currentColor;border-bottom:1.5px solid currentColor;transform:translateY(-70%) rotate(45deg);pointer-events:none}
@media(max-width:760px){.header[data-site-header] .header-tools{gap:12px}.header[data-site-header]>.mobile-nav{margin-top:0}.header .language-switch{font-size:13px}}
@media print{.theme-control{display:none}}