:root{--bg:#f7f8fa;--panel:#fff;--panel2:#eef2f5;--text:#20262e;--muted:#697386;--border:#d9e0e7;--accent:#2989b3;--accent2:#3a3939;--accentSoft:rgba(41,137,179,.12);--good:#1e7a4b;--warn:#986318;--bad:#a23b3b;--shadow:0 10px 30px rgba(20,30,40,.07)}
body.dark{--bg:#12171b;--panel:#1b2228;--panel2:#242d35;--text:#eff4f7;--muted:#a9b5bf;--border:#394650;--accent:#58b3d7;--accent2:#e1e7eb;--accentSoft:rgba(88,179,215,.15);--shadow:none}
*{box-sizing:border-box}body{margin:0;background:var(--bg);color:var(--text);font-family:Inter,ui-sans-serif,system-ui,-apple-system,BlinkMacSystemFont,"Segoe UI",sans-serif;line-height:1.5}button,input,select{font:inherit}button{cursor:pointer}.container{width:min(1200px,calc(100% - 28px));margin:auto}.site-header{background:radial-gradient(circle at 10% 0,var(--accentSoft),transparent 38%),var(--panel);border-bottom:1px solid var(--border);padding:34px 0 26px}.header-row{display:flex;justify-content:space-between;gap:24px;align-items:flex-start}.eyebrow{text-transform:uppercase;letter-spacing:.06em;font-size:.78rem;font-weight:800;color:var(--accent);margin:0 0 7px}h1{font-size:clamp(1.9rem,4vw,3.1rem);line-height:1.06;margin:0 0 10px}h2{font-size:1.35rem;margin:0 0 10px}h3{font-size:1.05rem;margin:0 0 7px}p{margin-top:0}.subtitle,.muted{color:var(--muted)}.subtitle{max-width:820px;margin-bottom:0}.tabs{display:flex;gap:8px;flex-wrap:wrap;padding:20px 0 8px}.tab,.secondary-btn,.primary-btn{border-radius:var(--r-md,14px);padding:9px 14px;border:1px solid var(--border);font-weight:700}.tab,.secondary-btn{background:var(--panel);color:var(--text)}.tab.active,.primary-btn{background:var(--accent);border-color:var(--accent);color:#fff}.tab-panel{display:none;padding:15px 0 48px}.tab-panel.active{display:block}.card{background:var(--panel);border:1px solid var(--border);border-radius:var(--r-lg,18px);padding:17px;box-shadow:var(--shadow)}.controls{display:grid;grid-template-columns:repeat(4,minmax(0,1fr));gap:12px}.controls label>span{display:block;color:var(--muted);font-size:.86rem;margin-bottom:5px}select,input[type="text"],input[type="number"],input[type="range"]{width:100%}select,input[type="text"],input[type="number"]{padding:9px 11px;background:var(--bg);color:var(--text);border:1px solid var(--border);border-radius:var(--r-sm,10px)}.stats{display:grid;grid-template-columns:repeat(4,1fr);gap:12px;margin:14px 0}.stat{background:var(--panel);border:1px solid var(--border);border-radius:var(--r-md,14px);padding:14px}.stat small{display:block;color:var(--muted)}.stat strong{display:block;font-size:1.65rem;margin:2px 0}.badge{display:inline-block;border-radius:999px;background:var(--accentSoft);color:var(--accent);font-weight:800;font-size:.8rem;padding:5px 9px;margin:0 5px 5px 0}.grid2{display:grid;grid-template-columns:1fr 1fr;gap:15px}.grid3{display:grid;grid-template-columns:repeat(3,1fr);gap:15px}.action-row{display:flex;gap:9px;flex-wrap:wrap;margin-top:12px}.note{padding:13px 15px;border-left:4px solid var(--accent);background:var(--accentSoft);border-radius:var(--r-sm,10px)}.table-wrap{overflow-x:auto;border:1px solid var(--border);border-radius:var(--r-md,14px)}table{width:100%;border-collapse:collapse;background:var(--panel)}th,td{padding:10px 12px;text-align:left;border-bottom:1px solid var(--border)}th{background:var(--panel2);font-size:.86rem}.section-head{margin-bottom:15px}.section-head p{color:var(--muted);margin:0}.feedback{font-weight:700;min-height:24px}.good{color:var(--good)}.warn{color:var(--warn)}.bad{color:var(--bad)}footer{border-top:1px solid var(--border);background:var(--panel);color:var(--muted);padding:24px 0}footer p{margin:0}@media(max-width:850px){.controls,.stats,.grid3{grid-template-columns:1fr 1fr}.grid2{grid-template-columns:1fr}.header-row{flex-direction:column}}@media(max-width:560px){.controls,.stats,.grid3{grid-template-columns:1fr}.container{width:min(100% - 18px,1200px)}.tabs{display:grid;grid-template-columns:1fr 1fr}.tab{width:100%}}

.property-toolbar{margin-bottom:14px}.periodic-scroll{overflow-x:auto;padding-bottom:8px}.periodic-table{display:grid;grid-template-columns:repeat(18,minmax(48px,1fr));grid-template-rows:repeat(9,62px);gap:4px;min-width:930px}.element{position:relative;border:1px solid var(--border);border-radius:var(--r-sm,10px);background:var(--panel);color:var(--text);padding:5px;display:flex;flex-direction:column;align-items:center;justify-content:center;transition:transform .12s,border-color .12s,opacity .12s}.element:hover,.element.selected{transform:translateY(-2px);border-color:var(--accent);z-index:2}.element .z{position:absolute;top:3px;left:5px;font-size:.62rem;color:var(--muted)}.element .sym{font-size:1.08rem;font-weight:800}.element .val{font-size:.62rem;color:var(--muted);white-space:nowrap;overflow:hidden;text-overflow:ellipsis;max-width:100%}.element.dim{opacity:.18}.element.no-data{background:repeating-linear-gradient(135deg,var(--panel),var(--panel) 7px,var(--panel2) 7px,var(--panel2) 12px)}.scale{display:flex;align-items:center;gap:10px;margin:10px 0 14px}.scale-bar{height:12px;flex:1;border-radius:999px;background:linear-gradient(90deg,var(--panel2),var(--accent))}.scale-labels{display:flex;justify-content:space-between;font-size:.76rem;color:var(--muted)}.element-detail dl{margin:0}.element-detail dl div{display:flex;justify-content:space-between;gap:12px;padding:7px 0;border-bottom:1px solid var(--border)}.element-detail dt{color:var(--muted)}.element-detail dd{margin:0;font-weight:700;text-align:right}.trend-arrows{display:grid;grid-template-columns:1fr 1fr;gap:10px;margin-top:12px}.arrow-box{background:var(--panel2);border-radius:var(--r-md,14px);padding:12px;text-align:center}.arrow-big{font-size:1.8rem;font-weight:800;color:var(--accent)}#propertyChart{width:100%;height:auto;display:block}.chart-axis{stroke:var(--border);stroke-width:1}.chart-line{fill:none;stroke:var(--accent);stroke-width:3}.chart-dot{fill:var(--accent)}.compare-slot{min-height:210px}.comparison-row{display:grid;grid-template-columns:1fr auto 1fr;gap:12px;align-items:center}.vs{font-weight:800;color:var(--muted)}.challenge-options{display:grid;grid-template-columns:1fr 1fr;gap:10px}.challenge-options button{min-height:80px}.legend-cats{display:flex;flex-wrap:wrap;gap:8px;margin-top:10px}.legend-cats span{font-size:.76rem;padding:4px 8px;border-radius:999px;background:var(--panel2)}@media(max-width:650px){.comparison-row{grid-template-columns:1fr}.vs{text-align:center}.trend-arrows{grid-template-columns:1fr}}
.grid2>*,.grid3>*{min-width:0}.property-toolbar,.mini-scroll,.table-wrap{max-width:100%}