:root{--bth-ink:#172b36;--bth-muted:#687b82;--bth-green:#245b52;--bth-blue:#2863ce;--bth-line:#e5eaec;--bth-surface:#fff;--bth-canvas:#f7f9fa;--bth-radius:12px;--bth-shadow:0 8px 28px rgba(19,45,51,.07)}
body{background:var(--bth-canvas);color:var(--bth-ink);font-family:system-ui,-apple-system,"Segoe UI",sans-serif;font-size:16px;line-height:1.7}
.site-header,.main-navigation,.site-footer{background:#fff}
.inside-header,.inside-navigation,.site-info{max-width:1440px;margin:auto}
.site-header{border-bottom:1px solid var(--bth-line)}
.site-branding .main-title a{color:var(--bth-ink);font-weight:750;letter-spacing:-.04em}
.main-navigation .main-nav ul li a{font-weight:600}
.main-navigation .main-nav ul li[class*=current-menu] a{color:var(--bth-green)}
.site-content{max-width:1440px;padding:28px 24px 64px}
.content-area{min-width:0}
.inside-article,.page .site-main>article,.single .site-main>article{background:transparent}
.entry-header{margin-bottom:24px}
.entry-title{color:var(--bth-ink);font-size:clamp(30px,4vw,48px);letter-spacing:-.045em;line-height:1.15;font-weight:750}
.entry-content{color:#344850}
.entry-content a{color:var(--bth-green);text-underline-offset:3px}
.entry-content h2,.entry-content h3{color:var(--bth-ink);letter-spacing:-.025em;line-height:1.25}
.entry-content h2{font-size:clamp(24px,3vw,34px);margin:1.6em 0 .6em}
.entry-content h3{font-size:22px;margin:1.35em 0 .55em}
.entry-content p,.entry-content li{max-width:78ch}
.bth-ui-button,.bth-detail-link,.bth-ui-button:visited{display:inline-flex;align-items:center;justify-content:center;gap:10px;background:var(--bth-green);color:#fff;border:0;border-radius:999px;padding:11px 18px;text-decoration:none;font-weight:650}
.bth-ui-button:hover,.bth-detail-link:hover{background:#173e38;color:#fff}
.bth-periodic-wrap{--bth-primary:var(--bth-blue);--bth-primary-dark:#174ea6;--bth-text:var(--bth-ink);--bth-muted:#687b82;display:grid;grid-template-columns:minmax(0,3fr) minmax(280px,1fr);align-items:start;column-gap:30px;width:100%;max-width:none;margin:0;padding:20px 0 28px;background:#fff;border:0;border-radius:0;box-shadow:none}
.bth-periodic-head{grid-column:1/-1;display:grid;grid-template-columns:minmax(0,1fr) minmax(220px,320px);align-items:end;margin-bottom:14px}
.bth-periodic-title{font-size:22px;font-weight:650;letter-spacing:-.02em}
.bth-periodic-desc{font-size:13px;line-height:1.55}
.bth-periodic-search input{height:44px;background:#f5f7fa;border:1px solid transparent;box-shadow:none;font-size:14px}
.bth-periodic-search input:focus{background:white;border-color:#a8c7fa;box-shadow:0 0 0 3px #d2e3fc}
.bth-periodic-filters{gap:5px}
.bth-desktop-filters{grid-column:3/13;grid-row:2/5;min-height:150px;box-shadow:none;border:0;background:transparent;backdrop-filter:none;padding:10px}
.bth-filter-btn{font-size:10px;font-weight:600;padding:7px 9px;text-transform:none}
.bth-filter-btn.is-active{background:#e8f0fe;border-color:#e8f0fe;color:#174ea6;box-shadow:none}
.bth-periodic-scroll{grid-column:1;grid-row:5;overflow-x:auto;padding:3px 3px 12px}
.bth-periodic-grid{grid-template-rows:repeat(9,minmax(58px,7vw));gap:2px;min-width:920px}
.bth-element{border:0!important;border-radius:5px!important;box-shadow:none!important;min-width:0;padding:5px 2px;text-decoration:none!important;transition:transform .14s,box-shadow .14s}
.bth-element:hover{transform:scale(1.04);z-index:3;box-shadow:0 2px 8px #20212428!important}
.bth-element.is-selected{outline:2px solid #4285f4;outline-offset:1px;z-index:2}
.bth-symbol{font-size:clamp(16px,2vw,27px);font-weight:400;line-height:1.15}
.bth-name{font-size:clamp(8px,.8vw,11px);font-weight:600;line-height:1.2}
.bth-atomic-number{font-size:9px;line-height:1.2}
.bth-mass{display:none}
.bth-cat-alkali{background:#dff4f9;color:#36758a}.bth-cat-alkaline{background:#fdeaea;color:#c52b33}.bth-cat-transition{background:#eee8fb;color:#6841d9}.bth-cat-post-transition{background:#def5e8;color:#194e20}.bth-cat-metalloid{background:#fff7df;color:#976017}.bth-cat-nonmetal{background:#e4edff;color:#2863ce}.bth-cat-halogen{background:#e4edff;color:#2863ce}.bth-cat-noble{background:#fbeaf0;color:#bd315c}.bth-cat-lanthanide{background:#e7f3fc;color:#28658a}.bth-cat-actinide{background:#fff0e4;color:#ba4728}
.bth-element-detail{grid-column:2;grid-row:5;position:sticky;top:18px;margin:0;max-width:390px;padding:8px 0 6px}
.bth-search-results,.bth-search-status,.bth-periodic-wrap>.bth-periodic-filters,.bth-periodic-note{grid-column:1/-1}
.bth-detail-top{display:grid;grid-template-columns:92px minmax(0,1fr);align-items:center;gap:18px}
.bth-detail-tile{height:100px;border-radius:8px;display:flex;flex-direction:column;justify-content:space-between;padding:7px 9px}
.bth-detail-tile small{font-size:11px}.bth-detail-tile strong{font-size:36px;font-weight:400;line-height:1}.bth-detail-tile span{font-size:11px;font-weight:650}
.bth-detail-top h2{font-size:clamp(24px,3vw,38px);font-weight:400;letter-spacing:-.04em;margin:4px 0}
.bth-detail-top p{font-size:13px;color:var(--bth-muted);margin:0}
.bth-detail-kicker{color:var(--bth-blue)!important;font-size:12px!important;font-weight:650}
.bth-detail-facts{display:grid;grid-template-columns:repeat(3,1fr);gap:12px;border-top:1px solid var(--bth-line);border-bottom:1px solid var(--bth-line);padding:14px 0;margin:18px 0}
.bth-detail-facts small{display:block;font-size:10px;color:var(--bth-muted)}.bth-detail-facts b{font-size:12px;font-weight:600;overflow-wrap:anywhere}
.bth-element-detail-empty{color:var(--bth-muted);font-size:13px}
.bth-detail-link{background:#1a73e8;padding:9px 15px;font-size:13px}
.bth-periodic-note{font-size:11px;color:var(--bth-muted);margin-top:8px}
.bth-ed-hero,.bth-resource-hero,.bth-element-overview,.bth-element-content,.bth-elements-type{border-radius:var(--bth-radius)}
.bth-ui-card,.bth-resource-card,.bth-element-card,.bth-ed-card{border-radius:var(--bth-radius);box-shadow:var(--bth-shadow)}
.bth-resource-filters input,.bth-ed-search input{border-radius:8px}
.site-footer{border-top:1px solid var(--bth-line)}
.site-info{color:var(--bth-muted)}
@media(max-width:900px){.bth-periodic-wrap{grid-template-columns:minmax(0,2fr) minmax(250px,1fr);column-gap:20px}.bth-periodic-head{grid-template-columns:1fr}.bth-periodic-search{width:100%;flex-basis:auto}.bth-desktop-filters{grid-column:3/13;grid-row:2/5}.bth-element-detail{max-width:none}}
@media(max-width:768px){.site-content{padding:18px 14px 44px}.bth-periodic-wrap{display:block;padding:14px 0 22px}.bth-periodic-head{gap:10px}.bth-periodic-title{font-size:20px}.bth-mobile-filters{display:flex;overflow-x:auto;flex-wrap:nowrap;padding:2px 0 8px}.bth-mobile-filters .bth-filter-btn{flex:0 0 auto}.bth-desktop-filters{display:none}.bth-periodic-grid{min-width:850px;grid-template-rows:repeat(9,58px)}.bth-periodic-search{width:100%}.bth-detail-facts{gap:8px}.bth-element-detail{position:static;padding:12px 0}.entry-title{font-size:32px}}

/* GeneratePress template layout and accessible interaction states. */
:root{--bth-color-primary:#2863ce;--bth-color-primary-hover:#174ea6;--bth-color-focus:#4285f4;--bth-color-text:#172b36;--bth-color-muted:#687b82;--bth-color-subtle:#f7f9fa;--bth-color-surface:#fff;--bth-color-border:#e5eaec;--bth-radius-card:12px;--bth-shadow-card:0 6px 20px #172b360a}
.bth-screen{width:100%;min-width:0;flex:1;background:#f7f9fa;border-radius:12px}
.bth-periodic-wrap .bth-element.is-filtered-out{opacity:.18}
.bth-periodic-wrap .bth-element::before{display:none}
.bth-periodic-wrap .bth-element[hidden],.bth-ed-card[hidden],.bth-lr-card[hidden]{display:none!important}
.bth-periodic-wrap .bth-periodic-grid{width:100%}
.bth-periodic-wrap .bth-symbol{color:inherit}
.bth-periodic-wrap .bth-name{color:inherit}
.bth-ui-pagination{display:flex;gap:8px;flex-wrap:wrap;margin:28px 0}
.bth-ui-pagination .page-numbers{padding:8px 14px;border-radius:8px;background:#fff}
.bth-ui-pagination .current{background:#e8f0fe;color:#174ea6}
.bth-author-intro{display:flex;gap:18px;align-items:center;margin:24px 0}
.bth-author-intro img{border-radius:50%}
.bth-single .bth-author-box-content_mobile{display:block!important}
.bth-screen--404 .bth-ui-badge{font-size:48px;letter-spacing:-2px;color:#2863ce;background:#e8f0fe}
@media(prefers-reduced-motion:reduce){.bth-periodic-wrap *{transition:none!important}}