/* ─── CSS Variables ─────────────────────────────────────────────────── */
:root {
  --bg-primary:    #1a1a24;
  --bg-secondary:  #22222e;
  --glass-bg:      rgba(255,255,255,0.06);
  --glass-border:  rgba(255,255,255,0.14);
  --glass-hover:   rgba(255,255,255,0.11);
  --glass-shine:   rgba(255,255,255,0.22);
  --text-primary:  rgba(255,255,255,0.92);
  --text-secondary:rgba(255,255,255,0.52);
  --text-muted:    rgba(255,255,255,0.32);
  --accent-blue:   #4fc3f7;
  --accent-indigo: #7c83f5;
  --accent-teal:   #4dd0c4;
  --radius-sm:     8px;
  --radius-md:     14px;
  --radius-lg:     22px;
  --shadow-glass:  0 8px 32px rgba(0,0,0,0.45), 0 1px 0 rgba(255,255,255,0.08) inset;
  --shadow-hover:  0 16px 48px rgba(0,0,0,0.6), 0 1px 0 rgba(255,255,255,0.14) inset;

  --space-xs: 4px;
  --space-sm: 8px;
  --space-md: 16px;
  --space-lg: 24px;
  --space-xl: 32px;
  --space-2xl: 40px;
  --space-3xl: 48px;

  --font-body: 'Inter', 'Nunito', 'Helvetica Neue', system-ui, -apple-system, sans-serif;
  --font-display: 'Playfair Display', Georgia, 'Times New Roman', serif;
  --font-mono: 'SF Mono', 'Fira Code', 'Cascadia Code', 'Consolas', monospace;

  --line-height-body: 1.6;
  --line-height-heading: 1.15;
  --letter-spacing-body: -0.01em;
  --letter-spacing-heading: -0.02em;

  --modal-bg:            rgba(18,18,28,0.55);
  --modal-border:        rgba(255,255,247,0.12);
  --modal-shadow:        0 24px 64px rgba(0,0,0,0.35), 0 1px 0 rgba(255,255,255,0.06) inset;
  --modal-shine:         linear-gradient(90deg, transparent, rgba(255,255,255,0.15), transparent);
  --overlay-bg:          rgba(0,0,0,0.4);
  --tooltip-bg:          rgba(20,20,30,0.9);
  --tooltip-border:      rgba(255,255,247,0.14);
  --scrollbar-thumb:     rgba(255,255,247,0.12);
  --search-focus-border: rgba(79,195,247,0.5);
  --search-focus-shadow: rgba(79,195,247,0.1);
  --ambient-a-color:     rgba(76,195,247,0.07);
  --ambient-b-color:     rgba(124,131,245,0.07);
  --ambient-3d-bg:       rgba(255,255,247,0.04);
  --detail-divider-bg:   linear-gradient(90deg, rgba(255,255,247,0.12), transparent);
  --title-gradient-from: #fff;
  --title-gradient-to:   rgba(255,255,255,0.55);
  --close-bg:            rgba(255,255,247,0.1);
  --close-border:        rgba(255,255,247,0.14);
  --close-color:         rgba(255,255,247,0.7);
  --close-hover-bg:      rgba(255,255,247,0.18);
  --modal-scrollbar:     rgba(255,255,247,0.1);
  --legend-active-border:rgba(255,255,247,0.3);

  /* Category palette */
  --c-alkali:       #ff6b9d;
  --c-alkaline:     #ffaa5c;
  --c-lanthanide:   #c879ff;
  --c-actinide:     #ff79c0;
  --c-transition:   #4fc3f7;
  --c-post-trans:   #7ee8a2;
  --c-metalloid:    #ffe066;
  --c-nonmetal:     #80deea;
  --c-halogen:      #f48fb1;
  --c-noble:        #b39ddb;
  --c-unknown:      #90a4ae;
}

/* ─── Light Theme ───────────────────────────────────────────────────── */
[data-theme="light"] {
  --bg-primary:    #f0f2f5;
  --bg-secondary:  #ffffff;
  --glass-bg:      rgba(255,255,247,0.65);
  --glass-border:  rgba(0,0,0,0.10);
  --glass-hover:   rgba(0,0,0,0.06);
  --glass-shine:   rgba(0,0,0,0.06);
  --text-primary:  rgba(0,0,0,0.88);
  --text-secondary:rgba(0,0,0,0.55);
  --text-muted:    rgba(0,0,0,0.38);
  --shadow-glass:  0 4px 20px rgba(0,0,0,0.07), 0 1px 0 rgba(255,255,255,0.6) inset;
  --shadow-hover:  0 12px 36px rgba(0,0,0,0.12), 0 1px 0 rgba(255,255,255,0.8) inset;
  --modal-bg:            rgba(255,255,255,0.72);
  --modal-border:        rgba(0,0,0,0.08);
  --modal-shadow:        0 16px 48px rgba(0,0,0,0.08), 0 1px 0 rgba(255,255,255,0.4) inset;
  --modal-shine:         linear-gradient(90deg, transparent, rgba(0,0,0,0.04), transparent);
  --overlay-bg:          rgba(0,0,0,0.15);
  --tooltip-bg:          rgba(255,255,255,0.94);
  --tooltip-border:      rgba(0,0,0,0.12);
  --scrollbar-thumb:     rgba(0,0,0,0.12);
  --search-focus-border: rgba(79,195,247,0.7);
  --search-focus-shadow: rgba(79,195,247,0.2);
  --ambient-a-color:     rgba(76,195,247,0.10);
  --ambient-b-color:     rgba(124,131,245,0.10);
  --ambient-3d-bg:       rgba(0,0,0,0.03);
  --detail-divider-bg:   linear-gradient(90deg, rgba(0,0,0,0.08), transparent);
  --title-gradient-from: #1a1a2e;
  --title-gradient-to:   rgba(0,0,0,0.5);
  --close-bg:            rgba(0,0,0,0.06);
  --close-border:        rgba(0,0,0,0.12);
  --close-color:         rgba(0,0,0,0.55);
  --close-hover-bg:      rgba(0,0,0,0.12);
  --modal-scrollbar:     rgba(0,0,0,0.1);
  --legend-active-border:rgba(0,0,0,0.3);
}

/* ─── Reset & Base ──────────────────────────────────────────────────── */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

html {
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
  text-size-adjust: 100%;
}

body {
  font-family: var(--font-body);
  font-size: 15px;
  line-height: var(--line-height-body);
  letter-spacing: var(--letter-spacing-body);
  background: var(--bg-primary);
  color: var(--text-primary);
  min-height: 100vh;
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  transition: background 0.4s ease, color 0.4s ease;
}

/* ─── Toolbar ───────────────────────────────────────────────────────── */
.toolbar {
  position: fixed; top: var(--space-md); right: var(--space-md); z-index: 200;
  display: flex; gap: var(--space-sm);
}
.tb-btn {
  width: 38px; height: 38px;
  border-radius: 50%;
  border: 1px solid var(--glass-border);
  background: var(--glass-bg);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  cursor: pointer;
  display: flex; align-items: center; justify-content: center;
  transition: background 0.4s ease, border-color 0.4s ease, transform 0.2s;
}
.tb-btn:hover { background: var(--glass-hover); transform: scale(1.08); }
.tb-icon { font-size: 16px; line-height: 1; transition: transform 0.3s; }
.tb-lang {
  font-size: 13px; font-weight: 700; color: var(--text-primary);
  line-height: 1; transition: color 0.4s ease;
}

/* ─── Ambient Background ────────────────────────────────────────────── */
.ambient {
  position: fixed; inset: 0; pointer-events: none; z-index: 0;
  overflow: hidden;
}
.ambient::before {
  content: '';
  position: absolute;
  width: 900px; height: 900px;
  border-radius: 50%;
  background: radial-gradient(circle, var(--ambient-a-color) 0%, transparent 70%);
  top: -200px; left: -200px;
  animation: driftA 20s ease-in-out infinite alternate;
  transition: background 0.4s ease;
}
.ambient::after {
  content: '';
  position: absolute;
  width: 700px; height: 700px;
  border-radius: 50%;
  background: radial-gradient(circle, var(--ambient-b-color) 0%, transparent 70%);
  bottom: -200px; right: -100px;
  animation: driftB 26s ease-in-out infinite alternate;
  transition: background 0.4s ease;
}
@keyframes driftA { to { transform: translate(120px, 80px) scale(1.15); } }
@keyframes driftB { to { transform: translate(-80px, -60px) scale(1.1); } }

/* ─── Particle Canvas ────────────────────────────────────────────────── */
#particleCanvas {
  position: fixed; inset: 0; z-index: 1;
  pointer-events: none;
  width: 100%; height: 100%;
  filter: contrast(120%) brightness(110%);
  opacity: 0.92;
}

/* ─── Particle Icons ─────────────────────────────────────────────────── */
#particleContainer {
  position: fixed; inset: 0; z-index: 1;
  pointer-events: none;
  overflow: hidden;
  perspective: 1000px;
}

.particle-icon {
  position: absolute;
  font-family: var(--font-body);
  font-weight: 600;
  pointer-events: none;
  will-change: transform, opacity, filter;
  user-select: none;
  line-height: 1;
  text-align: center;
  backface-visibility: hidden;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  letter-spacing: -0.02em;
}

/* ─── Header ────────────────────────────────────────────────────────── */
.header {
  position: relative; z-index: 10;
  padding: var(--space-3xl) var(--space-2xl) var(--space-lg);
  display: flex; align-items: flex-end; justify-content: space-between;
  flex-wrap: wrap; gap: var(--space-md);
  max-width: 1280px;
  margin: 0 auto;
}
.header-title h1 {
  font-family: var(--font-display);
  font-size: clamp(28px, 4.5vw, 52px);
  font-weight: 450;
  letter-spacing: var(--letter-spacing-heading);
  background: linear-gradient(135deg, var(--title-gradient-from) 30%, var(--title-gradient-to));
  -webkit-background-clip: text; -webkit-text-fill-color: transparent;
  background-clip: text;
  line-height: var(--line-height-heading);
  transition: background 0.4s ease;
}
.header-title p {
  color: var(--text-muted);
  font-size: 13px;
  font-weight: 400;
  margin-top: 6px;
  letter-spacing: 0.02em;
  transition: color 0.4s ease;
}

/* ─── Legend ────────────────────────────────────────────────────────── */
.legend {
  position: relative; z-index: 10;
  display: flex; flex-wrap: wrap; gap: var(--space-xs);
  padding: 0 var(--space-2xl) var(--space-lg);
  max-width: 1280px;
  margin: 0 auto;
}
.legend-item {
  display: flex; align-items: center; gap: 5px;
  font-size: 10.5px; font-weight: 500;
  color: var(--text-secondary);
  padding: 5px 12px 5px 9px;
  border-radius: 20px;
  background: var(--glass-bg);
  border: 1px solid var(--glass-border);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  cursor: pointer;
  letter-spacing: 0.01em;
  transition: all 0.2s, background 0.4s ease, color 0.4s ease, border-color 0.4s ease;
  white-space: nowrap;
}
.legend-item:hover { background: var(--glass-hover); color: var(--text-primary); }
.legend-item.active { border-color: var(--legend-active-border); color: var(--text-primary); }
.legend-dot {
  width: 7px; height: 7px; border-radius: 50%;
  flex-shrink: 0;
}

/* ─── Table Wrapper ─────────────────────────────────────────────────── */
.table-scroll {
  position: relative; z-index: 10;
  overflow-x: auto;
  padding: 0 var(--space-lg) var(--space-3xl);
  -webkit-overflow-scrolling: touch;
}
.table-scroll::-webkit-scrollbar { height: 4px; }
.table-scroll::-webkit-scrollbar-track { background: transparent; }
.table-scroll::-webkit-scrollbar-thumb { background: var(--scrollbar-thumb); border-radius: 2px; transition: background 0.4s ease; }

/* ─── Periodic Grid ─────────────────────────────────────────────────── */
.periodic-grid {
  display: grid;
  grid-template-columns: repeat(18, minmax(56px, 1fr));
  grid-template-rows: repeat(10, auto);
  gap: 6px;
  min-width: 1040px;
  max-width: 1280px;
  margin: 0 auto;
}

.series-label {
  grid-column: 3 / 4;
  display: flex; align-items: center; justify-content: flex-end;
  padding-right: 6px;
  font-size: 9px; font-weight: 500;
  color: var(--text-muted);
  letter-spacing: 0.04em;
  text-transform: uppercase;
}

/* ─── Liquid Glass Element Tile ─────────────────────────────────────── */
.element {
  position: relative;
  aspect-ratio: 1;
  border-radius: var(--radius-sm);
  border: 1px solid rgba(255,255,255,0.15);
  background: rgba(255,255,255,0.05);
  backdrop-filter: blur(18px) saturate(180%) contrast(1.05) brightness(1.04);
  -webkit-backdrop-filter: blur(18px) saturate(180%) contrast(1.05) brightness(1.04);
  box-shadow: 
    0 2px 8px rgba(0,0,0,0.25),
    0 0 0 0.5px rgba(255,255,255,0.1) inset,
    0 0 24px rgba(255,255,255,0.02);
  cursor: pointer;
  display: flex; flex-direction: column;
  align-items: center; justify-content: center;
  padding: 6px 3px;
  overflow: hidden;
  transition: transform 0.45s cubic-bezier(0.21, 1.02, 0.23, 1),
              box-shadow 0.45s cubic-bezier(0.21, 1.02, 0.23, 1),
              border-color 0.45s cubic-bezier(0.21, 1.02, 0.23, 1),
              background 0.45s cubic-bezier(0.21, 1.02, 0.23, 1);
  animation: tileIn 0.5s cubic-bezier(.34,1.4,.64,1) both;
  will-change: transform;
}

.element:nth-child(1)  { animation-delay: 0.02s; }
.element:nth-child(2)  { animation-delay: 0.04s; }
.element:nth-child(3)  { animation-delay: 0.06s; }

@keyframes tileIn {
  from { opacity: 0; transform: scale(0.8) translateY(6px); }
  to   { opacity: 1; transform: scale(1) translateY(0); }
}

/* Liquid Glass Layers */
.element::before {
  content: '';
  position: absolute; inset: 0;
  border-radius: inherit;
  background: 
    linear-gradient(135deg, 
      rgba(255,255,255,0.25) 0%, 
      rgba(255,255,255,0.08) 20%,
      rgba(255,255,255,0.02) 50%,
      transparent 70%);
  pointer-events: none;
  opacity: 0.8;
  transition: opacity 0.45s cubic-bezier(0.21, 1.02, 0.23, 1),
              background 0.45s cubic-bezier(0.21, 1.02, 0.23, 1);
  mix-blend-mode: screen;
}

/* Edge Refraction Highlight */
.element::after {
  content: '';
  position: absolute; inset: -2px;
  border-radius: calc(var(--radius-sm) + 2px);
  background: 
    radial-gradient(200px circle at var(--mouse-x, 50%) var(--mouse-y, 50%), 
      rgba(255,255,255,0.15) 0%, 
      transparent 60%);
  pointer-events: none;
  opacity: 0;
  transition: opacity 0.4s cubic-bezier(0.21, 1.02, 0.23, 1);
  mix-blend-mode: screen;
}

/* Liquid Glass Inner Glow */
.element > .liquid-glass-inner {
  position: absolute; inset: 1px;
  border-radius: inherit;
  background: 
    linear-gradient(180deg, 
      rgba(255,255,255,0.08) 0%, 
      rgba(255,255,255,0.02) 100%);
  pointer-events: none;
  opacity: 0.9;
}

/* Category Dot — legend-style colored circle */
.element > .el-cat-dot {
  position: absolute;
  top: 6px; left: 50%; transform: translateX(-50%);
  width: 7px; height: 7px;
  border-radius: 50%;
  background: var(--cat-color, #4fc3f7);
  opacity: 0.85;
  pointer-events: none;
  z-index: 2;
  box-shadow: 0 0 6px var(--cat-color, rgba(79,195,247,0.5));
  transition: opacity 0.4s ease, box-shadow 0.4s ease;
}

/* Category Color Glow */
.element > .category-glow {
  position: absolute; inset: -8px;
  border-radius: calc(var(--radius-sm) + 8px);
  background: radial-gradient(circle, 
    var(--cat-color, rgba(79, 195, 247, 0.18)) 0%, 
    transparent 70%);
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.4s cubic-bezier(0.21, 1.02, 0.23, 1);
  filter: blur(8px);
}

/* Hover State - Liquid Glass Activation */
.element:hover {
  transform: scale(1.14) translateY(-6px);
  border-color: rgba(255,255,255,0.25);
  background: rgba(255,255,255,0.08);
  backdrop-filter: blur(24px) saturate(200%) contrast(1.08) brightness(1.06);
  -webkit-backdrop-filter: blur(24px) saturate(200%) contrast(1.08) brightness(1.06);
  box-shadow: 
    0 20px 60px rgba(0,0,0,0.35),
    0 0 0 0.5px rgba(255,255,255,0.15) inset,
    0 0 48px var(--cat-color, rgba(79,195,247,0.12));
  z-index: 5;
}

.element:hover::before {
  opacity: 1;
  background: 
    linear-gradient(135deg, 
      rgba(255,255,255,0.35) 0%, 
      rgba(255,255,255,0.12) 20%,
      rgba(255,255,255,0.04) 50%,
      transparent 70%);
}

.element:hover::after {
  opacity: 1;
}

.element:hover > .el-cat-dot {
  opacity: 1;
  box-shadow: 0 0 10px var(--cat-color, rgba(79,195,247,0.7));
}

.element:hover > .category-glow {
  opacity: 1;
}

/* Active/Pressed State */
.element:active { 
  transform: scale(1.09) translateY(-3px);
  transition: transform 0.12s ease;
}

/* Light Theme Adjustments */
[data-theme="light"] .element {
  border-color: rgba(0,0,0,0.08);
  background: rgba(255,255,255,0.55);
  backdrop-filter: blur(18px) saturate(160%) contrast(1.02) brightness(1.02);
  -webkit-backdrop-filter: blur(18px) saturate(160%) contrast(1.02) brightness(1.02);
  box-shadow: 
    0 2px 12px rgba(0,0,0,0.08),
    0 0 0 0.5px rgba(255,255,255,0.6) inset;
}

[data-theme="light"] .element::before {
  background: 
    linear-gradient(135deg, 
      rgba(255,255,255,0.7) 0%, 
      rgba(255,255,255,0.25) 20%,
      rgba(255,255,255,0.08) 50%,
      transparent 70%);
}

[data-theme="light"] .element::after {
  background: 
    radial-gradient(200px circle at var(--mouse-x, 50%) var(--mouse-y, 50%), 
      rgba(0,0,0,0.06) 0%, 
      transparent 60%);
  mix-blend-mode: multiply;
}

[data-theme="light"] .element:hover {
  background: rgba(255,255,255,0.8);
  border-color: rgba(0,0,0,0.12);
  backdrop-filter: blur(24px) saturate(200%) contrast(1.08);
  -webkit-backdrop-filter: blur(24px) saturate(200%) contrast(1.08);
  box-shadow: 
    0 20px 60px rgba(0,0,0,0.12),
    0 0 0 0.5px rgba(255,255,255,0.8) inset,
    0 0 48px var(--cat-color, rgba(79,195,247,0.08));
}

.el-number {
  font-size: 8px;
  color: var(--text-muted);
  line-height: 1;
  align-self: flex-start;
  padding-left: 4px;
  font-weight: 500;
  letter-spacing: 0.02em;
  transition: color 0.4s ease;
}
.el-symbol {
  font-family: var(--font-body);
  font-size: 17px;
  font-weight: 700;
  letter-spacing: -0.02em;
  line-height: 1.1;
  color: var(--text-primary);
  transition: color 0.4s ease;
}
.el-name {
  font-size: 7.5px;
  color: var(--text-secondary);
  line-height: 1.15;
  text-align: center;
  max-width: 100%;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
  padding: 0 3px;
  font-weight: 500;
  letter-spacing: 0.01em;
  transition: color 0.4s ease;
}
.el-mass {
  font-size: 7.5px;
  color: var(--text-muted);
  line-height: 1;
  margin-top: 1px;
  font-weight: 400;
  letter-spacing: 0.02em;
  transition: color 0.4s ease;
}

.element.dimmed {
  opacity: 0.18;
  pointer-events: none;
}
.element.dimmed > .el-cat-dot {
  opacity: 0.15 !important;
}
.element.highlighted { opacity: 1; }

/* ─── Liquid Glass Active State ─────────────────────────────────────── */
.element.liquid-glass-active {
  border-color: rgba(255,255,255,0.35) !important;
  background: rgba(255,255,255,0.06) !important;
  backdrop-filter: url('#liquid-glass-realtime') blur(1px) contrast(1.15) brightness(1.06) saturate(1.12) !important;
  -webkit-backdrop-filter: url('#liquid-glass-realtime') blur(1px) contrast(1.15) brightness(1.06) saturate(1.12) !important;
  box-shadow:
    0 20px 60px rgba(0,0,0,0.4),
    0 0 0 1px rgba(255,255,255,0.18) inset,
    0 0 48px var(--cat-color, rgba(79,195,247,0.15)) !important;
  z-index: 5;
  transition: transform 0.45s cubic-bezier(0.21, 1.02, 0.23, 1),
              box-shadow 0.45s cubic-bezier(0.21, 1.02, 0.23, 1),
              border-color 0.45s cubic-bezier(0.21, 1.02, 0.23, 1);
}

[data-theme="light"] .element.liquid-glass-active {
  border-color: rgba(0,0,0,0.16) !important;
  background: rgba(255,255,255,0.7) !important;
  backdrop-filter: url('#liquid-glass-realtime') blur(1px) contrast(1.12) brightness(1.04) saturate(1.08) !important;
  -webkit-backdrop-filter: url('#liquid-glass-realtime') blur(1px) contrast(1.12) brightness(1.04) saturate(1.08) !important;
  box-shadow:
    0 20px 60px rgba(0,0,0,0.16),
    0 0 0 1px rgba(255,255,255,0.5) inset,
    0 0 48px var(--cat-color, rgba(79,195,247,0.1)) !important;
}

.element.liquid-glass-active::before,
.element.liquid-glass-active::after,
.element.liquid-glass-active > .el-cat-dot,
.element.liquid-glass-active > .category-glow {
  opacity: 1 !important;
}

.element.liquid-glass-active > .el-cat-dot {
  box-shadow: 0 0 12px var(--cat-color, rgba(79,195,247,0.8)) !important;
}

.element.liquid-glass-active > .category-glow {
  opacity: 1;
}

/* ─── Modal Overlay ──────────────────────────────────────────────────── */
.modal-overlay {
  position: fixed; inset: 0; z-index: 100;
  background: var(--overlay-bg);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  display: flex; align-items: center; justify-content: center;
  padding: 16px;
  opacity: 0; pointer-events: none;
  transition: opacity 0.3s ease, background 0.4s ease;
}
.modal-overlay.open {
  opacity: 1; pointer-events: all;
}

/* ─── Modal Card ─────────────────────────────────────────────────────── */
.modal-card {
  position: relative;
  width: 100%; max-width: 780px;
  max-height: 92vh;
  border-radius: var(--radius-lg);
  border: 1px solid var(--modal-border);
  background: var(--modal-bg);
  backdrop-filter: url('#liquid-glass-realtime') blur(0.5px) contrast(1.04) saturate(1.03);
  -webkit-backdrop-filter: url('#liquid-glass-realtime') blur(0.5px) contrast(1.04) saturate(1.03);
  box-shadow: var(--modal-shadow);
  overflow: hidden;
  display: grid;
  grid-template-columns: 1fr 1fr;
  transform: scale(0.92) translateY(20px);
  transition: transform 0.35s cubic-bezier(.34,1.4,.64,1),
              background 0.4s ease, border-color 0.4s ease, box-shadow 0.4s ease;
}
.modal-overlay.open .modal-card { transform: scale(1) translateY(0); }

@media (max-width: 640px) {
  .modal-card { grid-template-columns: 1fr; }
}

.modal-card::before {
  content: '';
  position: absolute; top: 0; left: 0; right: 0; height: 1px;
  background: var(--modal-shine);
  transition: background 0.4s ease;
}

/* ─── 3D Panel ───────────────────────────────────────────────────────── */
.modal-3d {
  position: relative;
  min-height: 280px;
  display: flex; align-items: center; justify-content: center;
  background: radial-gradient(ellipse at center, var(--ambient-3d-bg) 0%, transparent 75%);
  overflow: hidden;
  transition: background 0.4s ease;
}
#three-canvas {
  width: 100% !important;
  height: 100% !important;
  min-height: 280px;
}
.modal-3d-label {
  position: absolute;
  bottom: 12px; left: 50%; transform: translateX(-50%);
  font-size: 9.5px; font-weight: 500;
  color: var(--text-muted);
  letter-spacing: 0.06em; text-transform: uppercase;
  pointer-events: none;
  transition: color 0.4s ease;
}
.drag-hint {
  position: absolute;
  top: 12px; right: 12px;
  font-size: 9px; font-weight: 400;
  color: var(--text-muted);
  letter-spacing: 0.03em;
  display: flex; align-items: center; gap: 4px;
  transition: color 0.4s ease;
}

/* ─── Detail Panel ───────────────────────────────────────────────────── */
.modal-detail {
  padding: 28px 28px;
  display: flex; flex-direction: column;
  gap: 0;
  overflow-y: auto;
}
.modal-detail::-webkit-scrollbar { width: 4px; }
.modal-detail::-webkit-scrollbar-thumb { background: var(--modal-scrollbar); border-radius: 2px; transition: background 0.4s ease; }

.modal-close {
  position: absolute; top: 16px; right: 16px;
  width: 30px; height: 30px;
  border-radius: 50%;
  background: var(--close-bg);
  border: 1px solid var(--close-border);
  color: var(--close-color);
  cursor: pointer;
  display: flex; align-items: center; justify-content: center;
  font-size: 16px;
  transition: all 0.2s, background 0.4s ease, border-color 0.4s ease, color 0.4s ease;
  z-index: 10;
  backdrop-filter: blur(10px);
}
.modal-close:hover { background: var(--close-hover-bg); color: var(--text-primary); }

.detail-category {
  font-size: 10px;
  font-weight: 600;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--cat-color-modal, var(--accent-blue));
  margin-bottom: 8px;
  transition: color 0.4s ease;
}
.detail-symbol-row {
  display: flex; align-items: baseline; gap: 14px;
  margin-bottom: 4px;
}
.detail-symbol {
  font-family: var(--font-display);
  font-size: 68px;
  font-weight: 400;
  line-height: 1;
  color: var(--text-primary);
  letter-spacing: -0.03em;
  transition: color 0.4s ease;
}
.detail-number {
  font-size: 17px;
  color: var(--text-muted);
  font-weight: 400;
  font-family: var(--font-body);
  transition: color 0.4s ease;
}
.detail-name {
  font-family: var(--font-body);
  font-size: 24px;
  font-weight: 600;
  color: var(--text-primary);
  letter-spacing: -0.02em;
  margin-bottom: 18px;
  transition: color 0.4s ease;
}

.detail-divider {
  height: 1px;
  background: var(--detail-divider-bg);
  margin: 14px 0;
  transition: background 0.4s ease;
}

.detail-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 14px;
}
.detail-field {
  display: flex; flex-direction: column; gap: 2px;
}
.detail-field.full { grid-column: 1 / -1; }
.detail-label {
  font-size: 9px;
  font-weight: 600;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--text-muted);
  transition: color 0.4s ease;
}
.detail-value {
  font-size: 13.5px;
  color: var(--text-primary);
  font-weight: 500;
  word-break: break-word;
  letter-spacing: 0.01em;
  transition: color 0.4s ease;
}
.detail-value.mono {
  font-family: var(--font-mono);
  font-size: 11.5px;
  color: var(--accent-teal);
  letter-spacing: 0;
}

/* State badge */
.state-badge {
  display: inline-flex; align-items: center; gap: 4px;
  font-size: 11.5px; font-weight: 600;
  padding: 4px 12px; border-radius: 20px;
  border: 1px solid;
  letter-spacing: 0.01em;
  transition: color 0.4s ease, border-color 0.4s ease, background 0.4s ease;
}
.state-solid   { color: #7ee8a2; border-color: rgba(126,232,162,0.3); background: rgba(126,232,162,0.08); }
.state-liquid  { color: #4fc3f7; border-color: rgba(79,195,247,0.3);  background: rgba(79,195,247,0.08); }
.state-gas     { color: #ce93d8; border-color: rgba(206,147,216,0.3); background: rgba(206,147,216,0.08); }
.state-unknown { color: var(--text-muted); border-color: var(--glass-border); background: var(--glass-bg); transition: color 0.4s ease, border-color 0.4s ease, background 0.4s ease; }

[data-theme="light"] .state-solid   { background: rgba(126,232,162,0.12); color: #2e7d32; border-color: rgba(46,125,50,0.3); }
[data-theme="light"] .state-liquid  { background: rgba(79,195,247,0.12); color: #0277bd; border-color: rgba(2,119,189,0.3); }
[data-theme="light"] .state-gas     { background: rgba(206,147,216,0.12); color: #7b1fa2; border-color: rgba(123,31,162,0.3); }

/* ─── Tooltip ────────────────────────────────────────────────────────── */
.tooltip {
  position: fixed;
  pointer-events: none;
  z-index: 50;
  padding: 7px 14px;
  border-radius: var(--radius-sm);
  background: var(--tooltip-bg);
  border: 1px solid var(--tooltip-border);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  font-size: 12px;
  font-weight: 500;
  letter-spacing: 0.01em;
  color: var(--text-primary);
  white-space: nowrap;
  opacity: 0;
  transition: opacity 0.15s, background 0.4s ease, border-color 0.4s ease, color 0.4s ease;
  transform: translate(-50%, -120%);
}
.tooltip.show { opacity: 1; }

/* ─── Search bar ─────────────────────────────────────────────────────── */
.search-wrap {
  position: relative; z-index: 10;
  padding: 0 var(--space-2xl) var(--space-md);
  max-width: 380px;
  margin: 0 auto 0 0;
}
.search-input {
  width: 100%;
  padding: 10px 16px 10px 42px;
  border-radius: 24px;
  border: 1px solid var(--glass-border);
  background: var(--glass-bg);
  backdrop-filter: blur(16px);
  color: var(--text-primary);
  font-size: 13.5px;
  font-family: inherit;
  font-weight: 400;
  letter-spacing: 0.01em;
  outline: none;
  transition: border-color 0.2s, box-shadow 0.2s,
              background 0.4s ease, color 0.4s ease;
}
.search-input::placeholder {
  color: var(--text-muted);
  font-weight: 400;
  transition: color 0.4s ease;
}
.search-input:focus {
  border-color: var(--search-focus-border);
  box-shadow: 0 0 0 3px var(--search-focus-shadow);
}
.search-icon {
  position: absolute;
  left: calc(var(--space-2xl) + 14px); top: 50%; transform: translateY(-50%);
  color: var(--text-muted);
  font-size: 15px;
  pointer-events: none;
  transition: color 0.4s ease;
}

/* ─── Responsive ─────────────────────────────────────────────────────── */
@media (max-width: 1100px) {
  .header { padding: var(--space-xl) var(--space-lg) var(--space-md); }
  .legend { padding: 0 var(--space-lg) var(--space-md); }
  .search-wrap { padding: 0 var(--space-lg) var(--space-sm); }
  .search-icon { left: calc(var(--space-lg) + 14px); }
  .table-scroll { padding: 0 var(--space-md) var(--space-2xl); }
}

@media (max-width: 900px) {
  .header { padding: var(--space-lg) var(--space-md) var(--space-sm); }
  .legend, .search-wrap, .table-scroll { padding-left: var(--space-sm); padding-right: var(--space-sm); }
  .search-icon { left: calc(var(--space-sm) + 14px); }
  .modal-card { max-width: 95vw; }
}

@media (max-width: 640px) {
  .header { flex-direction: column; align-items: flex-start; gap: var(--space-sm); }
  .header-title h1 { font-size: 24px; }
  .search-wrap { max-width: 100%; }
  .modal-card { grid-template-columns: 1fr; max-height: 95vh; }
  .modal-3d { min-height: 200px; }
  #three-canvas { min-height: 200px; }
  .detail-symbol { font-size: 48px; }
  .detail-name { font-size: 20px; }
  .detail-grid { grid-template-columns: 1fr; }
  .modal-detail { padding: 20px 16px; }
  .periodic-grid { gap: 4px; grid-template-columns: repeat(18, minmax(44px, 1fr)); min-width: 850px; }
}