*{box-sizing:border-box}
:root{
  --panel:rgba(10,16,32,.92);
  --text:#f7fbff;
  --muted:#bfd0f3;
  --border:rgba(255,255,255,.14);
  --shadow:0 16px 42px rgba(0,0,0,.4);
  --radius:18px;
}
a {
  display: inline-block;
  padding: 10px 20px;
  background: rgb(0, 0, 0, .31);
  color: rgb(255, 255, 255);
  text-decoration: none;
  border-radius: 8px;
  margin: 5px;
}
body{
  margin:0;
  font-family:Inter,Arial,sans-serif;
  color:var(--text);
  background:
    radial-gradient(circle at top left, rgba(0,194,168,.12), transparent 22%),
    radial-gradient(circle at top right, rgba(155,93,229,.15), transparent 28%),
    linear-gradient(145deg,#02040a,#091126 40%,#050a17 100%);
}
.app{max-width:1720px;margin:0 auto;padding:18px}
.glass{
  background:var(--panel);
  border:1px solid var(--border);
  border-radius:var(--radius);
  box-shadow:var(--shadow);
  backdrop-filter:blur(12px);
}
.hero{display:grid;grid-template-columns:1.5fr 1fr;gap:18px;padding:22px;margin-bottom:18px}
.hero h1{margin:0 0 10px;font-size:clamp(30px,4vw,52px)}
.hero p{margin:0;color:var(--muted);line-height:1.7}
.nav-tabs{display:flex;flex-wrap:wrap;justify-content:flex-end;gap:10px}
button,input,select{
  border:1px solid rgba(255,255,255,.16);
  background:#0a0f1d;color:#fff;border-radius:14px;
  padding:12px 14px;font-size:14px;transition:.25s ease
}
button{cursor:pointer;font-weight:700}
button:hover{background:#111933;transform:translateY(-2px)}
.tab.active,.quick-btn.active{outline:2px solid rgba(125,211,252,.75)}
.toolbar{padding:14px;display:grid;grid-template-columns:2fr 1.2fr 1.2fr 1fr auto;gap:10px;margin-bottom:18px}
.layout{display:grid;grid-template-columns:minmax(0,1fr) 340px;gap:18px}
.view{display:none}.active-view{display:block}
.panel{padding:16px}
.legend-grid,.quick-grid,.mini-grid,.revision-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(150px,1fr));gap:10px}
.legend-item,.mini-card,.revision-card,.popup-chip{
  background:rgba(255,255,255,.04);border:1px solid rgba(255,255,255,.08);
  border-radius:14px;padding:12px
}
.legend-item{display:flex;align-items:center;gap:10px;color:var(--muted)}
.swatch{width:14px;height:14px;border-radius:50%}
.table-panel{overflow:auto;position:relative}
.periodic-table{display:grid;grid-template-columns:repeat(18,minmax(60px,1fr));gap:8px;min-width:1200px;padding-top:10px}
.blank,.element{min-height:84px;border-radius:16px}.blank{opacity:0}
.element{
  position:relative;border:1px solid rgba(255,255,255,.14);padding:8px 8px 10px;
  display:flex;flex-direction:column;justify-content:space-between;cursor:pointer;overflow:hidden;
  transition:transform .2s ease, box-shadow .2s ease, opacity .2s ease;color:#fff
}
.element::after{content:"";position:absolute;inset:0;background:linear-gradient(to top right, rgba(255,255,255,.06), transparent 55%);pointer-events:none}
.element:hover{transform:translateY(-4px) scale(1.03);box-shadow:0 12px 24px rgba(0,0,0,.28)}
.element.active{outline:3px solid rgba(255,255,255,.42)}
.element.dim{opacity:.12;filter:grayscale(.45)}
.element.lanth{box-shadow:0 0 0 1px rgba(239,71,111,.35) inset}
.element.act{box-shadow:0 0 0 1px rgba(6,214,160,.35) inset}
.num{font-size:11px;font-weight:700}.symbol{font-size:22px;font-weight:900;line-height:1}
.name{font-size:10px;font-weight:700;line-height:1.2}.meta{font-size:10px;opacity:.92}
.series-label{position:absolute;left:14px;font-size:12px;color:var(--muted);padding:4px 10px;border-radius:999px;background:rgba(255,255,255,.06);border:1px solid rgba(255,255,255,.08)}
.lanth-label{top:730px}.act-label{top:822px}
.sidebar{display:grid;gap:18px;align-content:start}.info-block{line-height:1.75;color:var(--muted)}.quick-grid{grid-template-columns:1fr 1fr}
#atomCanvas,#trendCanvas{width:100%;background:radial-gradient(circle at center, rgba(77,171,247,.08), rgba(0,0,0,.04));border-radius:22px;border:1px solid rgba(255,255,255,.1)}
.flash-toolbar{display:flex;flex-wrap:wrap;gap:10px;align-items:center;justify-content:space-between}.flash-controls{display:flex;gap:10px;flex-wrap:wrap}
.pill{padding:10px 12px;border-radius:999px;background:rgba(255,255,255,.06);border:1px solid rgba(255,255,255,.08)}
.flash-wrap{min-height:430px;display:grid;place-items:center}
.flashcard{width:min(580px,94vw);height:330px;position:relative;transform-style:preserve-3d;transition:transform .8s ease;cursor:pointer}
.flashcard.flipped{transform:rotateY(180deg)}
.flash-side{position:absolute;inset:0;border-radius:26px;border:1px solid rgba(255,255,255,.16);background:linear-gradient(135deg,#101833,#0a1020);display:grid;place-items:center;padding:28px;text-align:center;backface-visibility:hidden;box-shadow:var(--shadow)}
.flash-front .big-symbol{font-size:78px;font-weight:900}.flash-front .big-name{font-size:24px;margin-top:8px}
.flash-back{transform:rotateY(180deg);line-height:1.85;color:var(--muted);font-size:16px}
.group-grid{display:grid;grid-template-columns:1fr 1fr;gap:18px}
.chart-controls,.revision-top,.revision-actions{display:flex;gap:10px;flex-wrap:wrap;align-items:center}
.revision-top{justify-content:space-between;margin-bottom:14px}
.popup{position:fixed;inset:0;background:rgba(0,0,0,.78);display:grid;place-items:center;padding:16px}
.hidden{display:none!important}
.popup-card{width:min(920px,96vw);max-height:92vh;overflow:auto;padding:20px;position:relative;animation:popupIn .25s ease}
@keyframes popupIn{from{transform:translateY(18px) scale(.97);opacity:0}to{transform:translateY(0) scale(1);opacity:1}}
.close-btn{position:absolute;top:12px;right:12px;width:42px;height:42px;padding:0;font-size:22px}
.popup-title{display:flex;gap:16px;align-items:center;margin-bottom:14px}
.popup-badge{width:78px;height:78px;border-radius:20px;display:grid;place-items:center;font-size:30px;font-weight:900;border:1px solid rgba(255,255,255,.2)}
.popup-grid{display:grid;grid-template-columns:1fr 1fr;gap:12px}
.popup-chip strong{display:block;margin-bottom:6px;color:#fff}
.orbital-wrap{margin-top:14px}.orbital-boxes{display:grid;gap:8px}.orbital-row{display:flex;align-items:center;gap:10px;flex-wrap:wrap}
.boxset{display:flex;gap:6px;flex-wrap:wrap}.orbital-box{width:28px;height:28px;border:1px solid #445a82;border-radius:6px;display:grid;place-items:center;background:#07101d;font-size:14px}
@media print{
  body{background:#fff;color:#000}
  .hero,.toolbar,.sidebar,.popup,.legend-grid,.flash-toolbar,.nav-tabs,.series-label{display:none!important}
  .view{display:none!important}
  #revisionView{display:block!important}
  .glass,.revision-card{background:#fff!important;color:#000!important;box-shadow:none;border:1px solid #aaa}
}
@media (max-width:1100px){.hero,.layout,.group-grid{grid-template-columns:1fr}.lanth-label,.act-label{display:none}}
@media (max-width:760px){.toolbar{grid-template-columns:1fr}.popup-grid{grid-template-columns:1fr}}