/* TablaPeriodica.net — estilos globales (todas las páginas) */
:root{
  --papel:#F7F8F3; --tinta:#18222E; --tinta-2:#5A6675; --linea:#E3E6DC;
  --alc:#E4572E; --alt:#F0B429; --tra:#4A7DDE; --pos:#7E8AA2; --met:#2BAF9B;
  --nme:#3FA34D; --hal:#15A0C8; --gas:#B14BD1; --lan:#E0569C; --act:#C03546;
  --ok:#2E7D32; --mal:#C62828; --radio:10px;
}
*{box-sizing:border-box;margin:0;padding:0}
html{-webkit-text-size-adjust:100%}
body{
  font-family:'Instrument Sans',system-ui,sans-serif;color:var(--tinta);
  background-color:var(--papel);
  background-image:linear-gradient(var(--linea) 1px,transparent 1px),linear-gradient(90deg,var(--linea) 1px,transparent 1px);
  background-size:28px 28px;min-height:100vh;
}
.wrap{max-width:1240px;margin:0 auto;padding:14px 14px 90px}
/* ---------- Header: logo + marca + navegación ---------- */
header{display:flex;flex-direction:row;align-items:center;justify-content:space-between;gap:10px;
  flex-wrap:wrap;padding:6px 2px 10px}
.identidad{display:flex;align-items:center;gap:12px;text-decoration:none;color:inherit}
.logo-cuadro{flex:none;display:block;height:44px;width:auto}
.marca{font-family:'Bricolage Grotesque',sans-serif;font-weight:800;font-size:clamp(19px,4vw,25px);letter-spacing:-.5px;line-height:1.05}
.marca .net{color:var(--tra)}
.lema{font-size:12px;color:var(--tinta-2);margin-top:2px}
.nav-principal{display:flex;gap:6px;overflow-x:auto;scrollbar-width:none;padding-bottom:2px}
.nav-principal::-webkit-scrollbar{display:none}
.nav-principal a{flex:none;padding:7px 13px;border-radius:999px;font-size:13px;font-weight:600;
  text-decoration:none;color:var(--tinta);border:1.5px solid transparent}
.nav-principal a:hover{border-color:var(--linea);background:#fff}
.nav-principal a.activo{background:var(--tinta);color:#fff}
.nav-toggle{display:none;flex-direction:column;justify-content:center;gap:5px;width:42px;height:42px;
  border:1.5px solid var(--linea);border-radius:10px;background:#fff;cursor:pointer;padding:0 9px;flex:none}
.nav-toggle span{display:block;height:2.5px;width:100%;background:var(--tinta);border-radius:2px;transition:.25s}
.nav-toggle[aria-expanded="true"] span:nth-child(1){transform:translateY(7.5px) rotate(45deg)}
.nav-toggle[aria-expanded="true"] span:nth-child(2){opacity:0}
.nav-toggle[aria-expanded="true"] span:nth-child(3){transform:translateY(-7.5px) rotate(-45deg)}
.h1-seo{margin:0 0 16px;background:#fff;border:1.5px solid var(--linea);border-left:6px solid var(--tinta);
  border-radius:12px;padding:14px 18px}
.hero-ojal{display:block;font-size:10.5px;text-transform:uppercase;letter-spacing:.14em;
  color:var(--tra);font-weight:700;font-family:'Instrument Sans',sans-serif;margin-bottom:5px}
.h1-titulo{display:block;font-family:'Bricolage Grotesque',sans-serif;font-weight:800;
  font-size:clamp(21px,4.8vw,31px);letter-spacing:-.6px;line-height:1.12;color:var(--tinta)}
.h1-sub{display:block;font-family:'Instrument Sans',sans-serif;font-weight:500;
  font-size:clamp(13px,2.4vw,15.5px);color:var(--tinta-2);margin-top:6px;line-height:1.5;letter-spacing:0}
@media(max-width:759px){
  .nav-toggle{display:flex}
  .nav-principal{display:none;order:3;width:100%;flex-direction:column;gap:4px;overflow:visible;
    margin-top:8px;padding-top:8px;border-top:1px solid var(--linea)}
  .nav-principal.abierto{display:flex}
  .nav-principal a{padding:11px 14px;font-size:15px;border:1px solid var(--linea)}
}
@media(min-width:760px){
  .nav-toggle{display:none}
}

/* ---------- contenido indexable ---------- */
.contenido{max-width:760px;margin:34px auto 0;background:#fff;border:1.5px solid var(--linea);
  border-radius:14px;padding:22px 22px 14px}
.contenido h2{font-family:'Bricolage Grotesque';font-weight:700;font-size:19px;letter-spacing:-.3px;margin:18px 0 8px}
.contenido h2:first-child{margin-top:0}
.contenido p{font-size:14.5px;line-height:1.65;color:var(--tinta);margin-bottom:6px}
.contenido details{border-bottom:1px solid var(--linea);padding:10px 0}
.contenido summary{font-weight:600;font-size:14.5px;cursor:pointer;list-style-position:inside}
.contenido details p{margin:8px 0 2px;color:var(--tinta-2)}

footer{margin-top:26px;text-align:center;font-size:12px;color:var(--tinta-2)}
footer nav{margin-bottom:6px}
footer a{color:var(--tra);font-weight:600;text-decoration:none}
@media(prefers-reduced-motion:reduce){*{transition:none !important;animation:none !important}}