:root{--navy:#101438;--purple:#4b2ebf;--purple-dark:#29105f;--gold:#c28a2e;--cream:#fbf9ff;--ink:#171638;--muted:#6d6175;--line:#ded8e9}
*{box-sizing:border-box}html{scroll-behavior:smooth}body{margin:0;background:#f7f4fc;color:var(--ink);font-family:Montserrat,Arial,sans-serif;font-size:16px;line-height:1.5}a{color:inherit;text-decoration:none}button,input,select{font:inherit}.container{width:min(1440px,calc(100% - 40px));margin:auto}
.topbar{position:sticky;top:0;z-index:20;backdrop-filter:blur(16px);background:rgba(255,255,255,.92);border-bottom:1px solid var(--line)}.nav{display:flex;align-items:center;justify-content:space-between;gap:20px;padding:12px 0}.brand{display:flex;align-items:center;gap:10px;color:var(--navy)}.brand img{width:38px;height:38px;object-fit:contain}.brand-copy{display:flex;flex-direction:column;line-height:1.05}.brand-copy strong{font-weight:900;letter-spacing:.08em;font-size:.92rem}.brand-copy small{font-weight:700;letter-spacing:.12em;font-size:.58rem;color:var(--gold)}.btn{display:inline-flex;align-items:center;justify-content:center;gap:8px;border:1px solid transparent;border-radius:999px;padding:13px 20px;font-size:.94rem;font-weight:800;cursor:pointer;transition:.2s ease}.btn-primary{background:var(--navy);color:#fff}.btn-primary:hover{background:var(--purple);transform:translateY(-1px)}
.pt-hero{background:linear-gradient(112deg,var(--navy),#231456 72%,var(--purple));color:#fff;padding:42px 0 38px}.pt-hero-inner{display:flex;align-items:end;justify-content:space-between;gap:32px}.back-link{display:inline-block;color:#d9d2ef;font-size:.82rem;font-weight:700;margin-bottom:22px}.eyebrow{display:block;color:#e0b75d;font-size:.72rem;font-weight:800;letter-spacing:.14em;text-transform:uppercase}.pt-hero h1{font:600 clamp(2.5rem,5vw,4.8rem)/1.05 Lora,Georgia,serif;margin:8px 0 12px}.pt-hero p{max-width:760px;color:#d8d4e5;font-size:1.02rem;line-height:1.7;margin:0}.hero-key{width:154px;height:154px;flex:0 0 auto;border:1px solid rgba(255,255,255,.22);border-radius:50%;display:grid;place-content:center;text-align:center;background:rgba(255,255,255,.07)}.hero-key span{font:700 3.1rem/1 Lora,serif;color:#e0b75d}.hero-key small{width:90px;margin-top:7px;color:#fff;line-height:1.3}
.pt-workspace{padding:28px 0 70px}.pt-controls{display:grid;grid-template-columns:minmax(260px,1.6fr) 1fr 1fr auto;gap:12px;align-items:end;padding:18px;background:#fff;border:1px solid var(--line);border-radius:18px;box-shadow:0 12px 35px rgba(37,19,74,.07);margin-bottom:18px}.pt-controls label{display:grid;gap:7px}.pt-controls label>span{font-size:.73rem;font-weight:800;color:#5b5368}.pt-controls input,.pt-controls select{width:100%;height:46px;border:1px solid #d3ccdf;border-radius:10px;background:#fff;color:var(--ink);padding:0 12px;font:600 .85rem Montserrat,Arial,sans-serif}.pt-controls input:focus,.pt-controls select:focus{outline:3px solid rgba(75,46,191,.13);border-color:var(--purple)}#clearFilters{height:46px;border:1px solid var(--purple);border-radius:10px;background:#fff;color:var(--purple);padding:0 17px;font-weight:800;cursor:pointer}
.pt-content{display:grid;grid-template-columns:minmax(0,1fr) 330px;gap:18px;align-items:start}.table-column{min-width:0;background:#fff;border:1px solid var(--line);border-radius:20px;padding:18px;box-shadow:0 16px 40px rgba(37,19,74,.07)}.table-scroll{overflow-x:auto;padding-bottom:8px}.group-labels,.periodic-grid{min-width:1110px;display:grid;grid-template-columns:repeat(18,minmax(52px,1fr));gap:5px}.group-labels{margin-bottom:5px}.group-labels span{text-align:center;color:#8a8094;font-size:.63rem;font-weight:800}.periodic-grid{grid-template-rows:repeat(10,70px)}.element-cell{position:relative;border:1px solid transparent;border-radius:9px;padding:6px 5px;background:var(--cell-bg);color:#19172f;cursor:pointer;text-align:left;transition:transform .15s,box-shadow .15s,opacity .2s}.element-cell:hover,.element-cell:focus-visible,.element-cell.selected{z-index:2;transform:translateY(-3px);box-shadow:0 8px 18px rgba(24,17,58,.18);outline:2px solid var(--navy);outline-offset:1px}.element-cell.filtered{opacity:.1;pointer-events:none}.element-cell .number{display:block;font-size:.58rem;font-weight:800;opacity:.68}.element-cell .symbol{display:block;font:700 1.38rem/1.05 Lora,serif;margin-top:2px}.element-cell .name{display:block;overflow:hidden;text-overflow:ellipsis;white-space:nowrap;font-size:.49rem;font-weight:700;margin-top:3px}.series-label{align-self:center;padding-left:7px;color:#776d84;font-size:.62rem;font-weight:800}.series-spacer{border:1px dashed #d4cce1;border-radius:9px;display:grid;place-content:center;color:#756b83;background:#faf8fd;font-size:.62rem;font-weight:800;text-align:center}
.legend{display:flex;flex-wrap:wrap;gap:7px 12px;margin-top:16px}.legend button{display:inline-flex;align-items:center;gap:6px;border:0;background:transparent;color:#5d5569;font-size:.67rem;font-weight:700;cursor:pointer;padding:3px}.legend i{width:10px;height:10px;border-radius:3px;background:var(--legend-color)}.table-note{margin:16px 0 0;padding:13px 15px;border-left:3px solid var(--gold);background:#fbf6e8;color:#5c513e;font-size:.76rem;line-height:1.6}
.element-detail{position:sticky;top:96px;background:var(--navy);color:#fff;border-radius:20px;overflow:hidden;box-shadow:0 18px 45px rgba(24,17,58,.2)}.detail-top{padding:24px;background:linear-gradient(145deg,var(--detail-color),rgba(255,255,255,.18))}.detail-identity{display:flex;gap:16px;align-items:center}.detail-symbol{width:90px;height:100px;border:1px solid rgba(255,255,255,.48);border-radius:14px;padding:9px;display:flex;flex-direction:column;justify-content:space-between;background:rgba(16,20,56,.15)}.detail-symbol b{font-size:.72rem}.detail-symbol strong{font:700 2.8rem/1 Lora,serif}.detail-symbol small{font-size:.65rem}.detail-title h2{font:600 1.8rem/1.1 Lora,serif;margin:0 0 6px}.detail-title p{margin:0;color:rgba(255,255,255,.82);font-size:.78rem;line-height:1.5}.detail-body{padding:22px}.detail-grid{display:grid;grid-template-columns:1fr 1fr;gap:9px}.fact{border:1px solid rgba(255,255,255,.13);border-radius:10px;padding:10px}.fact span,.detail-section span{display:block;color:#aaa5bc;font-size:.61rem;text-transform:uppercase;letter-spacing:.08em;font-weight:800}.fact strong{display:block;margin-top:3px;font-size:.8rem}.detail-section{margin-top:18px}.detail-section p{font-size:.78rem;color:#d4d0df;line-height:1.65;margin:5px 0}.shells{display:flex;gap:6px;align-items:end;margin-top:9px}.shells i{display:grid;place-content:center;min-width:30px;height:30px;padding:0 5px;border-radius:50%;background:#fff;color:var(--purple);font-style:normal;font-size:.68rem;font-weight:900}.detail-actions{display:grid;gap:8px;margin-top:19px}.detail-actions a{min-height:42px;border-radius:9px;display:flex;align-items:center;justify-content:center;text-align:center;padding:8px 12px;font-size:.75rem;font-weight:800}.detail-actions a:first-child{background:#fff;color:var(--navy)}.detail-actions a:last-child{border:1px solid rgba(255,255,255,.38);color:#fff}
footer{background:#0b0e26;color:#bcb8cb;padding:24px 0}.footer-line{display:flex;justify-content:space-between;gap:20px;font-size:.74rem}.footer-line a{color:#fff;font-weight:800}
@media(max-width:1050px){.pt-content{grid-template-columns:1fr}.element-detail{position:static}.pt-controls{grid-template-columns:1fr 1fr}.search-control{grid-column:1/-1}}@media(max-width:680px){.container{width:min(100% - 24px,1440px)}.pt-hero{padding:32px 0}.pt-hero-inner{align-items:flex-start}.hero-key{width:96px;height:96px}.hero-key span{font-size:2.1rem}.hero-key small{font-size:.62rem}.pt-controls{grid-template-columns:1fr}.search-control{grid-column:auto}.table-column{padding:12px}.footer-line{flex-direction:column}}
@media(max-width:480px){.hero-key{display:none}.pt-hero h1{font-size:2.45rem}.pt-hero p{font-size:.9rem}}