* {
  box-sizing: border-box;
}

:root {
  --panel: rgba(10, 16, 32, 0.92);
  --text: #f7fbff;
  --muted: #bfd0f3;
  --border: rgba(255, 255, 255, 0.14);
  --shadow: 0 16px 42px rgba(0, 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, 0.12), transparent 22%),
    radial-gradient(circle at top right, rgba(155, 93, 229, 0.15), transparent 28%),
    linear-gradient(145deg, #02040a, #091126 40%, #050a17 100%);
}

.app {
  max-width: 1760px;
  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, 0.16);
  background: #0a0f1d;
  color: #fff;
  border-radius: 14px;
  padding: 12px 14px;
  font-size: 14px;
  transition: 0.25s ease;
}

button {
  cursor: pointer;
  font-weight: 700;
}

button:hover {
  background: #111933;
  transform: translateY(-2px);
}

.tab.active,
.quick-btn.active,
.popup-tab.active {
  outline: 2px solid rgba(125, 211, 252, 0.75);
}

.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,
.compare-grid {
  display: grid;
  gap: 12px;
}

.legend-grid,
.mini-grid,
.revision-grid {
  grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
}

.quick-grid {
  grid-template-columns: 1fr 1fr;
}

.compare-grid {
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
}

.legend-item,
.mini-card,
.revision-card,
.popup-chip,
.compare-item {
  background: rgba(255, 255, 255, 0.04);
  border: 1px solid rgba(255, 255, 255, 0.08);
  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%;
}

.compare-panel {
  margin-top: 18px;
}

.compare-top,
.compare-controls,
.chart-controls,
.revision-top,
.revision-actions,
.flash-toolbar,
.flash-controls,
.popup-tab-row {
  display: flex;
  gap: 10px;
  flex-wrap: wrap;
  align-items: center;
}

.compare-top,
.revision-top {
  justify-content: space-between;
}

.compare-controls {
  margin: 12px 0 14px;
}

.compare-controls select {
  min-width: 220px;
  flex: 1;
}

.compare-item {
  display: grid;
  grid-template-columns: 1fr;
  gap: 8px;
  min-height: 110px;
}

.compare-item span {
  color: var(--muted);
  font-size: 13px;
  line-height: 1.4;
}

.compare-item strong {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  gap: 12px;
  flex-wrap: wrap;
  word-break: break-word;
  line-height: 1.5;
  font-size: 15px;
}

.table-panel {
  overflow: auto;
  position: relative;
  margin-top: 18px;
}

.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, 0.14);
  padding: 8px 8px 10px;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  cursor: pointer;
  overflow: hidden;
  transition: transform 0.2s ease, box-shadow 0.2s ease, opacity 0.2s ease;
  color: #fff;
}

.element::after {
  content: "";
  position: absolute;
  inset: 0;
  background: linear-gradient(to top right, rgba(255, 255, 255, 0.06), transparent 55%);
  pointer-events: none;
}

.element:hover {
  transform: translateY(-4px) scale(1.03);
  box-shadow: 0 12px 24px rgba(0, 0, 0, 0.28);
}

.element.active {
  outline: 3px solid rgba(255, 255, 255, 0.42);
}

.element.dim {
  opacity: 0.12;
  filter: grayscale(0.45);
}

.element.lanth {
  box-shadow: 0 0 0 1px rgba(239, 71, 111, 0.35) inset;
}

.element.act {
  box-shadow: 0 0 0 1px rgba(6, 214, 160, 0.35) 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: 0.92;
}

.series-label {
  position: absolute;
  left: 14px;
  font-size: 12px;
  color: var(--muted);
  padding: 4px 10px;
  border-radius: 999px;
  background: rgba(255, 255, 255, 0.06);
  border: 1px solid rgba(255, 255, 255, 0.08);
}

.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);
}

#atomCanvas,
#trendCanvas {
  width: 100%;
  background: radial-gradient(circle at center, rgba(77, 171, 247, 0.08), rgba(0, 0, 0, 0.04));
  border-radius: 22px;
  border: 1px solid rgba(255, 255, 255, 0.1);
}

.flash-wrap {
  min-height: 430px;
  display: grid;
  place-items: center;
}

.pill {
  padding: 10px 12px;
  border-radius: 999px;
  background: rgba(255, 255, 255, 0.06);
  border: 1px solid rgba(255, 255, 255, 0.08);
}

.flashcard {
  width: min(580px, 94vw);
  height: 330px;
  position: relative;
  transform-style: preserve-3d;
  transition: transform 0.8s ease;
  cursor: pointer;
}

.flashcard.flipped {
  transform: rotateY(180deg);
}

.flash-side {
  position: absolute;
  inset: 0;
  border-radius: 26px;
  border: 1px solid rgba(255, 255, 255, 0.16);
  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;
}

.popup {
  position: fixed;
  inset: 0;
  background: rgba(0, 0, 0, 0.78);
  display: grid;
  place-items: center;
  padding: 16px;
}

.hidden {
  display: none !important;
}

.popup-card {
  width: min(960px, 96vw);
  max-height: 92vh;
  overflow: auto;
  padding: 20px;
  position: relative;
  animation: popupIn 0.25s ease;
}

@keyframes popupIn {
  from {
    transform: translateY(18px) scale(0.97);
    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, 0.2);
}

.popup-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 12px;
}

.popup-chip strong {
  display: block;
  margin-bottom: 6px;
  color: #fff;
}

.popup-tab-row {
  margin-bottom: 14px;
}

.popup-tab {
  padding: 10px 12px;
}

.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,
  .compare-panel {
    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;
  }

  .compare-controls {
    display: grid;
    grid-template-columns: 1fr;
  }

  .compare-item strong {
    flex-direction: column;
    align-items: flex-start;
  }
}