/* ═══════════════════════════════════════════════════
   PeriodicTable Pro Ultimate — style.css
   Aesthetic: Scientific Dark · Phosphor Green Accents
   ═══════════════════════════════════════════════════ */

@import url('https://fonts.googleapis.com/css2?family=Space+Mono:ital,wght@0,400;0,700;1,400&family=Outfit:wght@300;400;500;600;700&display=swap');

/* ── Fallback fonts (offline) ── */
:root {
  --font-mono: 'Space Mono', 'Courier New', monospace;
  --font-sans: 'Outfit', 'Segoe UI', system-ui, sans-serif;

  /* Dark palette */
  --bg:        #080c18;
  --bg-card:   #0e1427;
  --bg-panel:  #111827;
  --bg-hover:  #1a2235;
  --border:    #1e2d45;
  --border-hi: #2a4060;
  --text:      #e2eaf6;
  --text-dim:  #8899bb;
  --text-faint:#4a5a78;
  --accent:    #00f5a0;
  --accent2:   #00c8ff;
  --glow:      rgba(0,245,160,0.18);
  --glow2:     rgba(0,200,255,0.15);
  --shadow:    0 4px 32px rgba(0,0,0,0.6);

  /* Cell sizing */
  --cell: 52px;
  --gap:  3px;
  --radius: 6px;
  --radius-lg: 12px;
}

/* Light mode */
[data-theme="light"] {
  --bg:        #f0f4ff;
  --bg-card:   #ffffff;
  --bg-panel:  #e8edf8;
  --bg-hover:  #dce4f5;
  --border:    #c8d4e8;
  --border-hi: #94afd0;
  --text:      #1a2540;
  --text-dim:  #4a6080;
  --text-faint:#8099bb;
  --accent:    #00885a;
  --accent2:   #006fa8;
  --glow:      rgba(0,136,90,0.12);
  --glow2:     rgba(0,111,168,0.12);
  --shadow:    0 4px 24px rgba(30,60,120,0.12);
}

*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

html {
  font-size: 14px;
  scroll-behavior: smooth;
}

body {
  font-family: var(--font-sans);
  background: var(--bg);
  color: var(--text);
  min-height: 100vh;
  overflow-x: hidden;
  transition: background 0.3s, color 0.3s;
}

/* ── Noise texture overlay ── */
body::before {
  content: '';
  position: fixed; inset: 0;
  background-image: url("data:image/svg+xml,%3Csvg viewBox='0 0 256 256' xmlns='http://www.w3.org/2000/svg'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.9' numOctaves='4' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23n)' opacity='0.03'/%3E%3C/svg%3E");
  pointer-events: none;
  z-index: 0;
  opacity: 0.6;
}

/* ══════════════ HEADER ══════════════ */
#app-header {
  position: sticky; top: 0; z-index: 100;
  background: var(--bg-card);
  border-bottom: 1px solid var(--border);
  padding: 10px 20px;
  display: flex;
  align-items: center;
  gap: 16px;
  flex-wrap: wrap;
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  box-shadow: 0 2px 20px rgba(0,0,0,0.4);
}

.logo {
  display: flex;
  flex-direction: column;
  line-height: 1;
  flex-shrink: 0;
}
.logo-main {
  font-family: var(--font-mono);
  font-size: 1rem;
  font-weight: 700;
  color: var(--accent);
  letter-spacing: -0.02em;
}
.logo-sub {
  font-size: 0.65rem;
  color: var(--text-faint);
  letter-spacing: 0.15em;
  text-transform: uppercase;
}

/* Search */
.search-wrap {
  flex: 1;
  min-width: 180px;
  max-width: 380px;
  position: relative;
}
.search-wrap svg {
  position: absolute;
  left: 10px; top: 50%;
  transform: translateY(-50%);
  color: var(--text-faint);
  pointer-events: none;
}
#search-input {
  width: 100%;
  background: var(--bg-panel);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 8px 12px 8px 34px;
  color: var(--text);
  font-family: var(--font-sans);
  font-size: 0.9rem;
  outline: none;
  transition: border-color 0.2s, box-shadow 0.2s;
}
#search-input:focus {
  border-color: var(--accent);
  box-shadow: 0 0 0 3px var(--glow);
}
#search-input::placeholder { color: var(--text-faint); }

/* Header buttons */
.header-btns {
  display: flex;
  gap: 6px;
  flex-shrink: 0;
  align-items: center;
}
.btn-icon {
  background: var(--bg-panel);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 7px 12px;
  color: var(--text-dim);
  font-family: var(--font-mono);
  font-size: 0.75rem;
  cursor: pointer;
  transition: all 0.2s;
  display: flex; align-items: center; gap: 5px;
  white-space: nowrap;
}
.btn-icon:hover {
  border-color: var(--accent);
  color: var(--accent);
  background: var(--glow);
}
.btn-icon.active {
  border-color: var(--accent);
  color: var(--accent);
  background: var(--glow);
}

/* ══════════════ LEGEND ══════════════ */
#legend {
  display: flex;
  flex-wrap: wrap;
  gap: 6px 14px;
  padding: 10px 20px;
  border-bottom: 1px solid var(--border);
  background: var(--bg-card);
}
.legend-item {
  display: flex;
  align-items: center;
  gap: 5px;
  font-size: 0.7rem;
  color: var(--text-dim);
  cursor: pointer;
  padding: 3px 7px;
  border-radius: 4px;
  border: 1px solid transparent;
  transition: all 0.15s;
}
.legend-item:hover { background: var(--bg-hover); border-color: var(--border); }
.legend-item.active { border-color: var(--border-hi); background: var(--bg-hover); }
.legend-dot {
  width: 11px; height: 11px;
  border-radius: 3px;
  flex-shrink: 0;
}

/* ══════════════ MAIN LAYOUT ══════════════ */
#main-area {
  position: relative;
  z-index: 1;
  padding: 16px 12px 24px;
  overflow-x: auto;
  -webkit-overflow-scrolling: touch;
}

/* ══════════════ PERIODIC TABLE GRID ══════════════ */
#periodic-grid {
  display: grid;
  grid-template-columns: repeat(18, var(--cell));
  grid-template-rows: repeat(7, var(--cell));
  gap: var(--gap);
  width: max-content;
  margin: 0 auto;
}

/* Series label placeholders */
.series-label {
  display: flex;
  align-items: center;
  justify-content: center;
  font-family: var(--font-mono);
  font-size: 0.6rem;
  color: var(--text-faint);
  border: 1px dashed var(--border);
  border-radius: var(--radius);
  cursor: default;
  letter-spacing: 0.05em;
  text-align: center;
  line-height: 1.2;
  padding: 2px;
}

/* ══════════════ ELEMENT CELL ══════════════ */
.el-cell {
  position: relative;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  border-radius: var(--radius);
  cursor: pointer;
  border: 1px solid transparent;
  transition: transform 0.15s, box-shadow 0.15s, border-color 0.15s, filter 0.2s;
  overflow: hidden;
  background: var(--bg-card);
  user-select: none;
  -webkit-tap-highlight-color: transparent;
}

.el-cell::before {
  content: '';
  position: absolute; inset: 0;
  opacity: 0.18;
  background: var(--cat-color, transparent);
  transition: opacity 0.2s;
}

.el-cell:hover {
  transform: scale(1.15) translateZ(0);
  z-index: 10;
  border-color: var(--cat-color, var(--border-hi));
  box-shadow: 0 0 12px var(--cat-color, var(--glow)), var(--shadow);
}
.el-cell:hover::before { opacity: 0.35; }

.el-cell.highlight {
  border-color: var(--accent) !important;
  box-shadow: 0 0 10px var(--glow), 0 0 2px var(--accent) inset !important;
  z-index: 5;
}
.el-cell.dimmed {
  opacity: 0.2;
  filter: grayscale(0.8);
}

.el-num {
  font-family: var(--font-mono);
  font-size: 0.55rem;
  color: var(--text-faint);
  line-height: 1;
  margin-bottom: 1px;
}
.el-symbol {
  font-family: var(--font-mono);
  font-size: 1.05rem;
  font-weight: 700;
  line-height: 1;
  color: var(--text);
  position: relative; z-index: 1;
}
.el-name {
  font-size: 0.5rem;
  color: var(--text-dim);
  line-height: 1;
  margin-top: 2px;
  text-align: center;
  max-width: 46px;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
  position: relative; z-index: 1;
}
.el-mass {
  font-family: var(--font-mono);
  font-size: 0.45rem;
  color: var(--text-faint);
  margin-top: 1px;
  position: relative; z-index: 1;
}

/* State indicator dot */
.el-state {
  position: absolute;
  top: 3px; right: 3px;
  width: 4px; height: 4px;
  border-radius: 50%;
}
.state-gas    { background: var(--accent2); }
.state-solid  { background: #aaa; }
.state-liquid { background: #f6b93b; }
.state-unknown{ background: var(--text-faint); }

/* ══════════════ F-BLOCK SEPARATOR ══════════════ */
#f-block-area {
  width: max-content;
  margin: 14px auto 0;
  display: grid;
  grid-template-columns: repeat(18, var(--cell));
  gap: var(--gap);
}

.f-row-label {
  display: flex;
  align-items: center;
  justify-content: center;
  font-family: var(--font-mono);
  font-size: 0.58rem;
  color: var(--text-faint);
  letter-spacing: 0.04em;
  writing-mode: vertical-rl;
  text-orientation: mixed;
  padding: 4px 0;
  border-right: 1px dashed var(--border);
  margin-right: 4px;
}

#f-block-grid {
  width: max-content;
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  gap: var(--gap);
}
.f-block-row {
  display: flex;
  gap: var(--gap);
  align-items: center;
}
.f-row-tag {
  font-family: var(--font-mono);
  font-size: 0.58rem;
  color: var(--text-faint);
  width: 36px;
  text-align: right;
  padding-right: 6px;
  flex-shrink: 0;
  border-right: 1px dashed var(--border);
  margin-right: 2px;
}

/* ══════════════ GROUP/PERIOD LABELS ══════════════ */
#group-labels {
  display: grid;
  grid-template-columns: repeat(18, var(--cell));
  gap: var(--gap);
  width: max-content;
  margin: 0 auto 4px;
}
.group-lbl {
  text-align: center;
  font-family: var(--font-mono);
  font-size: 0.58rem;
  color: var(--text-faint);
  padding: 2px 0;
}

/* ══════════════ MODAL ══════════════ */
#modal-overlay {
  position: fixed; inset: 0; z-index: 200;
  background: rgba(4,8,20,0.82);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 20px;
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.22s;
}
#modal-overlay.open {
  opacity: 1;
  pointer-events: all;
}

#modal {
  background: var(--bg-card);
  border: 1px solid var(--border-hi);
  border-radius: var(--radius-lg);
  max-width: 560px;
  width: 100%;
  box-shadow: 0 0 60px rgba(0,0,0,0.8), 0 0 0 1px var(--border);
  transform: translateY(16px) scale(0.97);
  transition: transform 0.25s cubic-bezier(0.34,1.56,0.64,1);
  overflow: hidden;
  position: relative;
}
#modal-overlay.open #modal {
  transform: translateY(0) scale(1);
}

/* Modal hero */
.modal-hero {
  padding: 24px 28px 20px;
  position: relative;
  overflow: hidden;
}
.modal-hero::before {
  content: '';
  position: absolute; inset: 0;
  background: var(--modal-cat-color, var(--bg-hover));
  opacity: 0.12;
}
.modal-hero-symbol {
  font-family: var(--font-mono);
  font-size: 4.5rem;
  font-weight: 700;
  line-height: 1;
  color: var(--text);
  position: relative; z-index: 1;
  text-shadow: 0 0 30px var(--modal-cat-color, var(--accent));
}
.modal-hero-num {
  font-family: var(--font-mono);
  font-size: 0.8rem;
  color: var(--text-faint);
  margin-bottom: 4px;
  position: relative; z-index: 1;
}
.modal-hero-name {
  font-size: 1.5rem;
  font-weight: 600;
  color: var(--text);
  position: relative; z-index: 1;
}
.modal-hero-cn {
  font-size: 1.1rem;
  color: var(--text-dim);
  position: relative; z-index: 1;
  margin-top: 2px;
}
.modal-category-badge {
  display: inline-block;
  padding: 3px 10px;
  border-radius: 20px;
  font-size: 0.7rem;
  font-family: var(--font-mono);
  letter-spacing: 0.05em;
  border: 1px solid;
  margin-top: 10px;
  position: relative; z-index: 1;
}

/* Modal body */
.modal-body {
  padding: 16px 28px 24px;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 10px;
}
.modal-stat {
  background: var(--bg-panel);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 10px 14px;
  transition: border-color 0.15s;
}
.modal-stat:hover { border-color: var(--border-hi); }
.modal-stat-label {
  font-size: 0.65rem;
  color: var(--text-faint);
  text-transform: uppercase;
  letter-spacing: 0.1em;
  font-family: var(--font-mono);
  margin-bottom: 4px;
}
.modal-stat-value {
  font-size: 0.95rem;
  font-weight: 600;
  color: var(--text);
  font-family: var(--font-mono);
}
.modal-stat-unit {
  font-size: 0.65rem;
  color: var(--text-faint);
  margin-left: 3px;
}

/* Electron config full width */
.modal-stat.full { grid-column: 1 / -1; }

/* Electron shell visual */
.shell-diagram {
  display: flex;
  align-items: center;
  gap: 8px;
  margin-top: 6px;
  flex-wrap: wrap;
}
.shell-ring {
  display: flex;
  align-items: center;
  gap: 3px;
  font-family: var(--font-mono);
  font-size: 0.75rem;
}
.shell-label {
  color: var(--text-faint);
  font-size: 0.6rem;
}
.shell-count {
  background: var(--modal-cat-color, var(--accent));
  color: var(--bg);
  border-radius: 4px;
  padding: 1px 6px;
  font-weight: 700;
  font-size: 0.75rem;
}

/* Close button */
#modal-close {
  position: absolute;
  top: 16px; right: 16px;
  background: var(--bg-panel);
  border: 1px solid var(--border);
  border-radius: 6px;
  color: var(--text-dim);
  width: 32px; height: 32px;
  display: flex; align-items: center; justify-content: center;
  cursor: pointer;
  font-size: 1.1rem;
  z-index: 10;
  transition: all 0.2s;
}
#modal-close:hover { border-color: var(--accent); color: var(--accent); }

/* Nav arrows */
.modal-nav {
  display: flex;
  justify-content: space-between;
  padding: 0 28px 18px;
  gap: 10px;
}
.modal-nav-btn {
  flex: 1;
  background: var(--bg-panel);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 8px;
  color: var(--text-dim);
  font-family: var(--font-mono);
  font-size: 0.75rem;
  cursor: pointer;
  transition: all 0.2s;
  display: flex; align-items: center; justify-content: center; gap: 6px;
}
.modal-nav-btn:hover { border-color: var(--accent); color: var(--accent); }

/* ══════════════ FILTER PANEL ══════════════ */
#filter-notice {
  text-align: center;
  padding: 8px 20px;
  font-size: 0.72rem;
  color: var(--accent);
  font-family: var(--font-mono);
  background: var(--glow);
  border-bottom: 1px solid var(--border);
  display: none;
}
#filter-notice.show { display: block; }

/* ══════════════ TOAST ══════════════ */
#toast {
  position: fixed;
  bottom: 24px; right: 24px;
  background: var(--bg-card);
  border: 1px solid var(--accent);
  border-radius: 8px;
  padding: 10px 18px;
  font-size: 0.8rem;
  color: var(--accent);
  font-family: var(--font-mono);
  z-index: 300;
  transform: translateY(20px);
  opacity: 0;
  transition: all 0.25s;
  pointer-events: none;
}
#toast.show { transform: translateY(0); opacity: 1; }

/* ══════════════ RESPONSIVE ══════════════ */
@media (max-width: 900px) {
  :root { --cell: 40px; --gap: 2px; }
  .el-symbol { font-size: 0.85rem; }
  .el-name { font-size: 0.42rem; }
  .el-mass { display: none; }
}
@media (max-width: 640px) {
  :root { --cell: 32px; --gap: 2px; }
  .el-num { display: none; }
  .el-name { display: none; }
  .el-symbol { font-size: 0.72rem; }
  #legend { padding: 8px 12px; }
  #main-area { padding: 10px 6px; }
}
@media (max-width: 400px) {
  :root { --cell: 26px; --gap: 1px; }
  .el-symbol { font-size: 0.6rem; }
}

/* Scrollbar */
::-webkit-scrollbar { width: 6px; height: 6px; }
::-webkit-scrollbar-track { background: var(--bg); }
::-webkit-scrollbar-thumb { background: var(--border-hi); border-radius: 3px; }
::-webkit-scrollbar-thumb:hover { background: var(--accent); }

/* ── PWA install banner ── */
#pwa-banner {
  position: fixed;
  bottom: 0; left: 0; right: 0;
  background: var(--bg-card);
  border-top: 1px solid var(--border);
  padding: 12px 20px;
  display: flex;
  align-items: center;
  gap: 12px;
  z-index: 150;
  transform: translateY(100%);
  transition: transform 0.3s;
  box-shadow: 0 -4px 20px rgba(0,0,0,0.3);
}
#pwa-banner.show { transform: translateY(0); }
#pwa-banner span { font-size: 0.82rem; color: var(--text-dim); flex: 1; }
#pwa-install { 
  background: var(--accent);
  color: var(--bg);
  border: none;
  border-radius: 6px;
  padding: 7px 16px;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  font-weight: 700;
  cursor: pointer;
}
#pwa-dismiss {
  background: none;
  border: none;
  color: var(--text-faint);
  cursor: pointer;
  font-size: 1.1rem;
  line-height: 1;
}

/* animations */
@keyframes fadeIn {
  from { opacity: 0; transform: translateY(6px); }
  to   { opacity: 1; transform: translateY(0); }
}
.el-cell { animation: fadeIn 0.3s both; }

/* stagger via nth-child ranges */
.el-cell:nth-child(1n)  { animation-delay: calc(var(--i, 0) * 2ms); }