/* Compact learning surfaces. Icons: locally bundled Lucide Static. */
:root{--study-ink:#22372d;--study-muted:#748078;--study-line:#e3e9e3;--study-paper:#fff;--study-bg:#f7f9f6;--study-green:#2d694c;--study-soft:#edf5ec;--study-radius:18px}
.ui-icon{display:inline-block;width:20px;height:20px;object-fit:contain;flex-shrink:0;vertical-align:middle}
.site-header.wrap{min-height:80px;padding-block:16px;gap:20px;border-bottom:1px solid var(--study-line)}.site-header .brand{gap:10px}.site-header .brand>img{width:36px;height:36px;border-radius:10px}.site-header .brand>span{font-size:1.2rem;letter-spacing:-.045em;color:var(--study-ink)}.site-header .brand small{display:none}.site-header .desktop-nav{gap:6px;font-size:.84rem}.site-header .desktop-nav>a{display:inline-flex;align-items:center;gap:7px;padding:10px 12px;color:#59675e;border-radius:10px;text-decoration:none;font-weight:800}.site-header .desktop-nav>a[aria-current],.site-header .desktop-nav>a:hover{background:var(--study-soft);color:var(--study-green)}.site-header .desktop-nav .ui-icon{width:17px;height:17px;opacity:.72}.clean-nav-more{position:relative}.clean-nav-more>summary{display:flex;align-items:center;gap:7px;cursor:pointer;padding:10px 12px;font-size:.84rem;font-weight:800;list-style:none}.clean-nav-more>summary::-webkit-details-marker{display:none}.clean-nav-more>nav{position:absolute;z-index:20;right:0;top:100%;min-width:210px;border:1px solid var(--study-line);border-radius:14px;padding:10px;background:#fff;box-shadow:0 10px 40px #18332212;display:grid;gap:2px}.clean-nav-more>nav>a{display:flex;gap:9px;align-items:center;padding:10px;border-radius:8px;color:var(--study-ink);text-decoration:none}.clean-nav-more>nav>a:hover{background:var(--study-bg)}.site-header .mobile-nav>summary{font-size:.85rem;padding:10px 14px;border:1px solid var(--study-line);box-shadow:none;border-radius:11px;background:#fff}.site-header .mobile-nav nav a{display:flex;align-items:center;gap:10px}.site-header .mobile-nav .ui-icon{width:17px;height:17px}

/* Keep filtering functional in the colorful library. */
main#main [data-learning-skill][hidden]{display:none!important}