:root{--milk:#eeeee7;--paper:#fafaf5;--ink:#213633;--soft:#445651;--muted:#78817c;--line:rgba(33,54,51,.14);--alkali:#e7b7a7;--alkaline:#ead6a0;--transition:#d9c5b9;--post-transition:#bfd1c4;--metalloid:#a8c9bd;--nonmetal:#b8d5a8;--halogen:#d7d89d;--noble:#afccdc;--lanthanide:#c7b7d7;--actinide:#d8b3c6;--unknown:#d8d8d0}*{box-sizing:border-box}html,body{min-height:100%;margin:0}body{color:var(--ink);font-family:Arial,Helvetica,sans-serif;background:radial-gradient(circle at 50% 8%,#fff,transparent 37%),linear-gradient(145deg,var(--paper),var(--milk) 62%,#dfdfd6)}button{font:inherit;color:inherit}.pse-app{min-height:100dvh;padding:18px clamp(14px,3vw,38px) 30px}.app-head{display:flex;align-items:center;gap:14px;min-height:60px}.app-head a,.app-head img{display:block;width:44px;height:44px}.app-head img{filter:brightness(0) saturate(100%) invert(20%) sepia(18%) saturate(673%) hue-rotate(122deg) brightness(92%) contrast(90%)}h1,h2,p{margin:0}.app-head h1{font-size:1.25rem}.eyebrow{display:block;margin-bottom:3px;color:var(--muted);font-size:.69rem;font-weight:700;letter-spacing:.12em;text-transform:uppercase}.table-view{width:min(1500px,100%);margin:34px auto 0}.intro{display:flex;align-items:end;justify-content:space-between;gap:22px;margin-bottom:22px}.intro h2{font-size:clamp(1.65rem,3vw,2.8rem)}.intro p{color:var(--soft);font-size:.9rem}.table-scroll{overflow-x:auto;padding:4px 2px 14px;scrollbar-color:rgba(33,54,51,.22) transparent}.periodic-table{display:grid;grid-template-columns:repeat(18,64px);grid-template-rows:22px repeat(7,68px) 18px repeat(2,68px);gap:5px;min-width:1237px}.group-number{align-self:end;color:var(--muted);font-size:.66rem;text-align:center}.element{position:relative;display:grid;grid-template-rows:auto 1fr auto;min-width:0;padding:5px;border:1px solid rgba(33,54,51,.18);border-radius:8px;background:var(--element-color);text-align:left;cursor:pointer;transition:transform .13s ease,box-shadow .13s ease,filter .13s ease}.element:hover,.element:focus-visible{z-index:2;outline:none;transform:translateY(-2px) scale(1.04);box-shadow:0 8px 18px rgba(33,54,51,.18);filter:saturate(1.08)}.element-number{font-size:.58rem}.element-symbol{align-self:center;font-size:1.45rem;font-weight:700;text-align:center}.element-name{overflow:hidden;font-size:.56rem;text-overflow:ellipsis;white-space:nowrap}.series-label{display:flex;align-items:center;padding:0 8px;border:1px dashed var(--line);border-radius:8px;color:var(--muted);font-size:.68rem}.legend{display:flex;flex-wrap:wrap;gap:8px 16px;margin-top:18px}.legend span{display:flex;align-items:center;gap:7px;color:var(--soft);font-size:.75rem}.legend i{width:14px;height:14px;border:1px solid var(--line);border-radius:4px;background:var(--element-color)}.detail-view{display:grid;min-height:calc(100dvh - 92px);place-items:center;padding:20px}.back-button{position:fixed;top:24px;left:24px;padding:10px 13px;border:1px solid var(--line);border-radius:11px;background:rgba(250,250,245,.82);cursor:pointer;backdrop-filter:blur(12px)}.element-detail{display:grid;grid-template-columns:minmax(230px,390px) minmax(230px,360px);gap:clamp(28px,6vw,76px);align-items:center}.detail-tile{display:grid;aspect-ratio:1;padding:clamp(20px,3vw,34px);border:2px solid rgba(33,54,51,.25);border-radius:28px;background:var(--element-color);box-shadow:0 28px 70px rgba(33,54,51,.14)}.detail-number{font-size:clamp(1rem,2vw,1.35rem)}.detail-symbol{place-self:center;font-size:clamp(7rem,16vw,12rem);font-weight:700;line-height:.8}.detail-name{align-self:end;font-size:clamp(1.45rem,4vw,2.6rem)}.detail-info h2{font-size:clamp(2.2rem,6vw,4.7rem)}.detail-mass{margin:8px 0 28px;color:var(--soft);font-size:clamp(1.3rem,3vw,2rem)}.facts{display:grid;grid-template-columns:1fr 1fr;gap:1px;margin:0;overflow:hidden;border:1px solid var(--line);border-radius:16px;background:var(--line)}.facts div{padding:14px;background:rgba(250,250,245,.82)}.facts dt{color:var(--muted);font-size:.7rem;font-weight:700;letter-spacing:.08em;text-transform:uppercase}.facts dd{margin:5px 0 0;font-size:1rem}.load-error{margin:80px auto;text-align:center}.category-alkali{--element-color:var(--alkali)}.category-alkaline{--element-color:var(--alkaline)}.category-transition{--element-color:var(--transition)}.category-post-transition{--element-color:var(--post-transition)}.category-metalloid{--element-color:var(--metalloid)}.category-nonmetal{--element-color:var(--nonmetal)}.category-halogen{--element-color:var(--halogen)}.category-noble{--element-color:var(--noble)}.category-lanthanide{--element-color:var(--lanthanide)}.category-actinide{--element-color:var(--actinide)}.category-unknown{--element-color:var(--unknown)}@media(max-width:720px){.pse-app{padding:12px 10px 22px}.app-head{padding-left:4px}.table-view{margin-top:20px}.intro{align-items:start;flex-direction:column;gap:8px}.periodic-table{grid-template-columns:repeat(18,54px);grid-template-rows:20px repeat(7,59px) 16px repeat(2,59px);min-width:1057px}.element-symbol{font-size:1.18rem}.detail-view{padding:74px 8px 18px}.back-button{top:14px;left:14px}.element-detail{grid-template-columns:1fr;width:min(420px,100%);gap:24px}.detail-tile{width:min(82vw,330px);place-self:center}.detail-info{text-align:center}.facts{text-align:left}}