/* ============================================================
   Variables y reset
   ============================================================ */
:root {
  --cell-w: 56px;
  --cell-h: 64px;
  --cell-gap: 2px;
  --panel-w: 300px;
  --page-bg: #f4f6f8;
  --card-bg: #ffffff;
  --header-bg: #ffffff;
  --border-color: rgba(0, 0, 0, 0.08);
  --text-main: #1a1a2e;
  --text-muted: #6b7280;
  --search-bg: #f1f5f9;

  /* Texto de celdas (modo claro) */
  --cell-symbol-color: #1a1a2e;
  --cell-number-color: rgba(0, 0, 0, 0.50);
  --cell-name-color:   rgba(0, 0, 0, 0.60);
  --cell-border-color: rgba(0, 0, 0, 0.10);

  /* Colores pastel por categoría */
  --c-alkali-metal:    #ffc8c8;
  --c-alkaline-earth:  #ffe0b0;
  --c-transition-metal:#b8d8ff;
  --c-post-transition: #b8f0cc;
  --c-metalloid:       #fff0a0;
  --c-nonmetal:        #ccf5b0;
  --c-halogen:         #e8c0ff;
  --c-noble-gas:       #b0eeff;
  --c-lanthanide:      #ffd4a8;
  --c-actinide:        #d0b8ff;
  --c-unknown:         #e4e4e4;
}

/* ============================================================
   Tema oscuro — redefine las mismas variables bajo data-theme="dark"
   ============================================================ */
html[data-theme="dark"] {
  --page-bg: #0f0f1a;
  --card-bg: #1a1a2e;
  --header-bg: #12122a;
  --border-color: rgba(255, 255, 255, 0.08);
  --text-main: #e8e8f0;
  --text-muted: #9090a8;
  --search-bg: #1e1e38;

  /* Pastel oscuros: misma hue, menos luminosidad, más saturación */
  --c-alkali-metal:    #8b3a3a;
  --c-alkaline-earth:  #7a5428;
  --c-transition-metal:#2a4a7a;
  --c-post-transition: #1e6644;
  --c-metalloid:       #6a6020;
  --c-nonmetal:        #3a6620;
  --c-halogen:         #5a2e7a;
  --c-noble-gas:       #1a5a78;
  --c-lanthanide:      #7a4a20;
  --c-actinide:        #4a2e7a;
  --c-unknown:         #2e2e3e;

  /* Texto de celdas en modo oscuro */
  --cell-symbol-color: #f0f0fa;
  --cell-number-color: rgba(255, 255, 255, 0.55);
  --cell-name-color:   rgba(255, 255, 255, 0.70);
  --cell-border-color: rgba(255, 255, 255, 0.12);
}

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

body {
  font-family: system-ui, -apple-system, 'Segoe UI', sans-serif;
  background: var(--page-bg);
  color: var(--text-main);
  min-height: 100vh;
}

/* ============================================================
   Asignación de color por categoría (reutilizable en celdas,
   panel y leyenda mediante la variable --cat-color)
   ============================================================ */
.cat-alkali-metal    { --cat-color: var(--c-alkali-metal); }
.cat-alkaline-earth  { --cat-color: var(--c-alkaline-earth); }
.cat-transition-metal{ --cat-color: var(--c-transition-metal); }
.cat-post-transition { --cat-color: var(--c-post-transition); }
.cat-metalloid       { --cat-color: var(--c-metalloid); }
.cat-nonmetal        { --cat-color: var(--c-nonmetal); }
.cat-halogen         { --cat-color: var(--c-halogen); }
.cat-noble-gas       { --cat-color: var(--c-noble-gas); }
.cat-lanthanide      { --cat-color: var(--c-lanthanide); }
.cat-actinide        { --cat-color: var(--c-actinide); }
.cat-unknown         { --cat-color: var(--c-unknown); }

/* ============================================================
   Header
   ============================================================ */
.site-header {
  background: var(--header-bg);
  border-bottom: 1px solid var(--border-color);
  padding: 12px 24px;
  display: flex;
  align-items: center;
  gap: 24px;
  flex-wrap: wrap;
  position: sticky;
  top: 0;
  z-index: 100;
  box-shadow: 0 1px 4px rgba(0,0,0,0.06);
}

.header-brand h1 {
  font-size: 18px;
  font-weight: 700;
  color: var(--text-main);
  white-space: nowrap;
}

.search-box {
  flex: 1;
  min-width: 220px;
  max-width: 380px;
}

#search {
  width: 100%;
  padding: 8px 14px 8px 36px;
  border: 1.5px solid var(--border-color);
  border-radius: 24px;
  background: var(--search-bg) url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='16' height='16' viewBox='0 0 24 24' fill='none' stroke='%236b7280' stroke-width='2'%3E%3Ccircle cx='11' cy='11' r='8'/%3E%3Cline x1='21' y1='21' x2='16.65' y2='16.65'/%3E%3C/svg%3E") no-repeat 10px center;
  font-size: 14px;
  color: var(--text-main);
  outline: none;
  transition: border-color 0.2s;
}

#search:focus {
  border-color: #6b9fce;
  background-color: var(--card-bg);
}

.theme-toggle-btn {
  padding: 7px 14px;
  border: 1.5px solid var(--border-color);
  border-radius: 20px;
  background: var(--search-bg);
  color: var(--text-main);
  font-size: 13px;
  font-weight: 600;
  cursor: pointer;
  white-space: nowrap;
  transition: background 0.15s, border-color 0.15s;
  flex-shrink: 0;
}

.theme-toggle-btn:hover {
  background: var(--card-bg);
  border-color: var(--text-muted);
}

/* ============================================================
   Page layout: tabla (fluida) + panel (fijo)
   ============================================================ */
.page-layout {
  display: grid;
  grid-template-columns: 1fr;
  gap: 20px;
  align-items: start;
  padding: 20px 24px;
}

.page-layout.panel-open {
  grid-template-columns: minmax(0, 1fr) var(--panel-w);
}

/* La tabla hace scroll horizontal si la ventana es estrecha */
.table-area {
  overflow-x: auto;
  padding-bottom: 8px;
}

/* ============================================================
   Cabecera de grupos (números 1-18)
   ============================================================ */
.group-header {
  display: grid;
  grid-template-columns: repeat(18, var(--cell-w));
  gap: var(--cell-gap);
  margin-bottom: 4px;
}

.group-label {
  text-align: center;
  font-size: 9px;
  font-weight: 600;
  color: var(--text-muted);
  line-height: 14px;
  height: 14px;
}

/* ============================================================
   Tabla periódica principal (18 columnas, posición explícita)
   ============================================================ */
.table-grid {
  display: grid;
  grid-template-columns: repeat(18, var(--cell-w));
  gap: var(--cell-gap);
}

/* ============================================================
   Separador entre tabla y bloque f (≥ 1 fila de espacio)
   ============================================================ */
.f-block-sep {
  height: calc(var(--cell-h) + var(--cell-gap) * 2);
}

/* ============================================================
   Bloque f (lantánidos/actínidos) - grid de 16 columnas
   Columna 1: etiqueta de serie (ancho = 2 celdas + 1 gap)
   Columnas 2-16: 15 elementos
   La col 1 mide calc(2*56px + 2px)=114px para alinear col 2
   con el grupo 3 de la tabla principal.
   ============================================================ */
.f-block-grid {
  display: grid;
  grid-template-columns: calc(2 * var(--cell-w) + var(--cell-gap)) repeat(15, var(--cell-w));
  gap: var(--cell-gap);
}

.fblock-label {
  display: flex;
  align-items: center;
  justify-content: flex-end;
  padding-right: 8px;
  font-size: 10px;
  font-weight: 600;
  color: var(--text-muted);
  height: var(--cell-h);
}

/* ============================================================
   Celda de elemento
   ============================================================ */
.element-cell {
  width: var(--cell-w);
  height: var(--cell-h);
  background-color: var(--cat-color, #eee);
  border: 1px solid var(--cell-border-color);
  border-radius: 5px;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: space-between;
  padding: 3px 3px 4px;
  cursor: pointer;
  transition: transform 0.12s ease, box-shadow 0.12s ease, opacity 0.18s ease;
  position: relative;
  user-select: none;
}

.element-cell:hover {
  transform: translateY(-3px) scale(1.06);
  box-shadow: 0 6px 14px rgba(0, 0, 0, 0.18);
  z-index: 5;
}

.element-cell.selected {
  outline: 2.5px solid var(--text-main);
  outline-offset: 1px;
  box-shadow: 0 0 0 4px rgba(128,128,160,0.25);
  z-index: 6;
}

.element-cell.dimmed {
  opacity: 0.12;
}

.element-cell.placeholder {
  cursor: default;
  opacity: 0.75;
}

.element-cell.placeholder:hover {
  transform: none;
  box-shadow: none;
}

.el-number {
  font-size: 9px;
  color: var(--cell-number-color);
  align-self: flex-start;
  line-height: 1;
}

.el-symbol {
  font-size: 20px;
  font-weight: 700;
  line-height: 1;
  color: var(--cell-symbol-color);
}

.el-name {
  font-size: 7px;
  color: var(--cell-name-color);
  text-align: center;
  line-height: 1.1;
  max-width: 100%;
  overflow: hidden;
  white-space: nowrap;
  text-overflow: ellipsis;
}

/* ============================================================
   Panel de detalles (solo aparece en el layout cuando .panel-open)
   ============================================================ */
.detail-panel {
  display: none;
  width: var(--panel-w);
  background: var(--card-bg);
  border-radius: 14px;
  box-shadow: 0 2px 16px rgba(0, 0, 0, 0.09);
  overflow: hidden;
  position: sticky;
  top: 74px; /* debajo del header fijo */
}

.page-layout.panel-open .detail-panel {
  display: block;
}

/* Cabecera del panel (con color de la categoría) */
.panel-header {
  background-color: var(--cat-color, #e8e8e8);
  padding: 20px 20px 16px;
  display: flex;
  flex-direction: column;
  align-items: center;
  position: relative;
}

.close-btn {
  position: absolute;
  top: 10px;
  right: 10px;
  background: rgba(0, 0, 0, 0.12);
  border: none;
  border-radius: 50%;
  width: 26px;
  height: 26px;
  font-size: 12px;
  cursor: pointer;
  color: #333;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: background 0.15s;
}

.close-btn:hover {
  background: rgba(0, 0, 0, 0.22);
}

.panel-number {
  font-size: 12px;
  color: rgba(0, 0, 0, 0.45);
  font-weight: 600;
  letter-spacing: 0.05em;
}

.panel-symbol {
  font-size: 58px;
  font-weight: 800;
  line-height: 1;
  color: #1a1a2e;
}

.panel-name {
  font-size: 16px;
  font-weight: 600;
  color: #222;
  margin-top: 2px;
}

/* Cuerpo del panel con la tabla de propiedades */
.panel-body {
  display: grid;
  grid-template-columns: 118px 1fr;
  gap: 0;
  padding: 0;
}

.panel-body dt,
.panel-body dd {
  padding: 9px 16px;
  font-size: 13px;
  border-bottom: 1px solid var(--border-color);
}

.panel-body dt {
  font-weight: 600;
  color: var(--text-muted);
  font-size: 11px;
  text-transform: uppercase;
  letter-spacing: 0.04em;
  display: flex;
  align-items: center;
}

.panel-body dd {
  color: var(--text-main);
  font-weight: 500;
  word-break: break-all;
}

/* La config electrónica ocupa las dos columnas */
.panel-body dt.full,
.panel-body dd.full {
  grid-column: 1 / -1;
}

/* ============================================================
   Footer y leyenda
   ============================================================ */
.site-footer {
  padding: 20px 24px 32px;
}

.legend {
  display: flex;
  flex-wrap: wrap;
  gap: 8px 16px;
  background: var(--card-bg);
  border-radius: 10px;
  padding: 16px 20px;
  box-shadow: 0 1px 6px rgba(0,0,0,0.06);
}

.legend-item {
  display: flex;
  align-items: center;
  gap: 6px;
  font-size: 12px;
  color: var(--text-main);
  white-space: nowrap;
}

.legend-swatch {
  width: 18px;
  height: 18px;
  border-radius: 4px;
  background-color: var(--cat-color, #eee);
  border: 1px solid rgba(0,0,0,0.10);
  flex-shrink: 0;
}

/* ============================================================
   Responsive básico
   ============================================================ */
@media (max-width: 900px) {
  .page-layout.panel-open {
    grid-template-columns: 1fr;
  }
  .detail-panel {
    width: 100%;
    position: static;
  }
}