:root{
  --navy:#0a2342; --navy2:#123663; --azul:#1d6fd1; --aqua:#22b8cf; --aqua-cl:#e3f6fa;
  --fondo:#f5fafd; --blanco:#fff; --texto:#13263d; --suave:#56708a; --borde:#d8e7f0;
  --ok:#1a9b6c; --mal:#d2483f; --radio:16px; --max:1120px;
}
*{box-sizing:border-box;margin:0;padding:0}
html{scroll-behavior:smooth}
body{font-family:"Karla",system-ui,-apple-system,Segoe UI,Roboto,sans-serif;color:var(--texto);background:var(--fondo);line-height:1.7;font-size:17px}
svg{max-width:100%;display:block}
a{color:var(--azul)}
h1,h2,h3{font-family:"Sora",system-ui,sans-serif;line-height:1.2;color:var(--navy);letter-spacing:-.01em}
h1{font-size:clamp(2.1rem,5.4vw,3.6rem);font-weight:700}
h2{font-size:clamp(1.6rem,3.4vw,2.35rem);font-weight:700;margin-bottom:.5rem}
h3{font-size:1.12rem;font-weight:600;margin-bottom:.3rem}
p+p{margin-top:.8rem}
.wrap{max-width:var(--max);margin:0 auto;padding:0 20px}
.eyebrow{display:inline-block;font-family:"Sora",sans-serif;font-size:.78rem;font-weight:600;letter-spacing:.14em;text-transform:uppercase;color:var(--aqua);margin-bottom:10px}
.intro{max-width:700px;color:var(--suave);margin-bottom:34px}

.aviso-top{background:var(--navy);color:#bfe9f1;text-align:center;font-size:.86rem;padding:8px 16px;border-bottom:1px solid rgba(255,255,255,.08)}

header.site{position:sticky;top:0;z-index:20;background:rgba(255,255,255,.88);backdrop-filter:blur(10px);border-bottom:1px solid var(--borde);transition:box-shadow .3s}
header.site.scrolled{box-shadow:0 6px 24px rgba(10,35,66,.08)}
header.site .wrap{display:flex;align-items:center;justify-content:space-between;gap:16px;min-height:68px}
.logo{display:flex;align-items:center;gap:10px;font-family:"Sora",sans-serif;font-weight:700;color:var(--navy);text-decoration:none;font-size:1.25rem}
.logo svg{width:32px;height:32px}
nav.menu{display:flex;gap:6px}
nav.menu a{text-decoration:none;color:var(--suave);font-weight:600;font-size:.92rem;padding:6px 12px;border-radius:999px;transition:background .2s,color .2s}
nav.menu a:hover,nav.menu a.activo{background:var(--aqua-cl);color:var(--navy)}
.progreso{position:absolute;left:0;bottom:-1px;height:3px;width:0;background:linear-gradient(90deg,var(--aqua),var(--azul))}

/* HERO */
.hero{position:relative;background:linear-gradient(180deg,var(--navy) 0%,var(--navy2) 100%);color:#fff;padding:84px 0 170px;overflow:hidden;text-align:center}
.hero h1{color:#fff;max-width:860px;margin:0 auto}
.hero h1 .resalta{background:linear-gradient(90deg,#7fe3f2,var(--aqua));-webkit-background-clip:text;background-clip:text;color:transparent}
.hero p.lead{color:#c5d9ec;font-size:1.15rem;max-width:640px;margin:20px auto 30px}
.btn{display:inline-block;background:var(--aqua);color:var(--navy);font-weight:700;text-decoration:none;padding:14px 28px;border-radius:999px;font-family:"Sora",sans-serif;font-size:.95rem;transition:transform .2s,box-shadow .2s}
.btn:hover{transform:translateY(-2px);box-shadow:0 10px 26px rgba(34,184,207,.35)}
.btn.sec{background:transparent;color:#fff;border:2px solid rgba(255,255,255,.35);margin-left:8px}
.gota-hero{width:74px;margin:0 auto 18px;animation:flota 4s ease-in-out infinite}
@keyframes flota{0%,100%{transform:translateY(0)}50%{transform:translateY(-10px)}}
.burbujas span{position:absolute;bottom:-20px;border-radius:50%;background:rgba(127,227,242,.18);animation:sube linear infinite}
@keyframes sube{to{transform:translateY(-110vh);opacity:0}}
.olas{position:absolute;left:0;bottom:0;width:100%;height:140px}
.olas svg{position:absolute;bottom:0;width:200%;height:100%}
.ola1{animation:mar 14s linear infinite;opacity:.35}
.ola2{animation:mar 9s linear infinite reverse;opacity:.6}
.ola3{animation:mar 18s linear infinite}
@keyframes mar{from{transform:translateX(0)}to{transform:translateX(-50%)}}

/* Contadores */
.stats{margin-top:-70px;position:relative;z-index:2}
.stats .grid{display:grid;grid-template-columns:repeat(4,1fr);gap:16px}
.stat{background:#fff;border:1px solid var(--borde);border-radius:var(--radio);padding:24px 20px;box-shadow:0 12px 30px rgba(10,35,66,.06)}
.stat .num{font-family:"Sora",sans-serif;font-weight:700;font-size:2.2rem;color:var(--azul);line-height:1}
.stat p{color:var(--suave);font-size:.93rem;margin-top:8px}
.fuente{font-size:.78rem;color:var(--suave);margin-top:14px;font-style:italic}

section.bloque{padding:84px 0}
section.alt{background:#fff;border-top:1px solid var(--borde);border-bottom:1px solid var(--borde)}

/* Planeta: barra de distribución */
.dist{display:grid;grid-template-columns:1fr 1fr;gap:48px;align-items:center}
.barra{display:flex;height:56px;border-radius:12px;overflow:hidden;margin:18px 0 12px;background:var(--aqua-cl)}
.barra div{height:100%;width:0;transition:width 1.6s cubic-bezier(.2,.8,.2,1)}
.barra .sal{background:linear-gradient(90deg,var(--navy2),var(--azul))}
.barra .dulce{background:var(--aqua)}
.leyenda{display:flex;gap:20px;flex-wrap:wrap;font-size:.92rem;color:var(--suave)}
.leyenda i{display:inline-block;width:12px;height:12px;border-radius:3px;margin-right:6px;vertical-align:middle}
.vaso{background:#fff;border:1px solid var(--borde);border-radius:var(--radio);padding:26px}
.vaso-ilu{display:flex;gap:16px;align-items:flex-end;justify-content:center;margin-top:12px}
.vaso-ilu figure{text-align:center;font-size:.82rem;color:var(--suave)}
.vaso-ilu .rec{width:70px;border:3px solid var(--borde);border-top:0;border-radius:0 0 12px 12px;position:relative;overflow:hidden;background:#fff}
.vaso-ilu .rec span{position:absolute;left:0;bottom:0;width:100%;height:0;background:var(--aqua);transition:height 1.6s ease}

/* Ciclo con pestañas */
.ciclo{display:grid;grid-template-columns:1.1fr .9fr;gap:40px;align-items:center}
.tabs{display:flex;gap:8px;flex-wrap:wrap;margin-bottom:18px}
.tab{border:1px solid var(--borde);background:#fff;color:var(--suave);font:600 .92rem "Karla",sans-serif;padding:9px 16px;border-radius:999px;cursor:pointer;transition:all .2s}
.tab[aria-selected="true"]{background:var(--navy);color:#fff;border-color:var(--navy)}
.panel{background:var(--fondo);border:1px solid var(--borde);border-radius:var(--radio);padding:24px;min-height:150px}
.panel[hidden]{display:none}
.panel p{color:var(--suave)}
.ciclo-svg .paso-c{opacity:.25;transition:opacity .4s}
.ciclo-svg .paso-c.on{opacity:1}

/* Cuerpo */
.cuerpo{display:grid;grid-template-columns:repeat(3,1fr);gap:18px}
.card{background:#fff;border:1px solid var(--borde);border-radius:var(--radio);padding:24px;transition:transform .25s,box-shadow .25s}
.card:hover{transform:translateY(-4px);box-shadow:0 14px 30px rgba(10,35,66,.08)}
.card .ico{width:44px;height:44px;border-radius:12px;background:var(--aqua-cl);display:grid;place-items:center;margin-bottom:12px;color:var(--azul)}
.card .ico svg{width:24px;height:24px}
.card p{color:var(--suave);font-size:.96rem}
section.alt .card{background:var(--fondo)}

/* Calculadora */
.calc{display:grid;grid-template-columns:1.1fr .9fr;gap:28px;align-items:stretch}
.calc-form{background:#fff;border:1px solid var(--borde);border-radius:var(--radio);padding:28px}
.campo{margin-bottom:22px}
.campo label{display:flex;justify-content:space-between;font-weight:600;margin-bottom:8px;gap:12px}
.campo label output{color:var(--azul);font-family:"Sora",sans-serif;white-space:nowrap}
input[type=range]{width:100%;accent-color:var(--azul);height:6px}
.switch{display:flex;gap:8px}
.switch button{flex:1;border:1px solid var(--borde);background:#fff;padding:10px;border-radius:10px;font:600 .9rem "Karla",sans-serif;color:var(--suave);cursor:pointer}
.switch button[aria-pressed="true"]{background:var(--aqua-cl);border-color:var(--aqua);color:var(--navy)}
.calc-res{background:linear-gradient(160deg,var(--navy),var(--navy2));color:#fff;border-radius:var(--radio);padding:30px;display:flex;flex-direction:column;justify-content:center;position:relative;overflow:hidden}
.calc-res .litros{font-family:"Sora",sans-serif;font-size:3.2rem;font-weight:700;line-height:1;color:#7fe3f2}
.calc-res .unidad{color:#c5d9ec;margin-top:6px}
.tanque{height:14px;background:rgba(255,255,255,.12);border-radius:999px;margin:22px 0 10px;overflow:hidden}
.tanque span{display:block;height:100%;width:0;background:linear-gradient(90deg,var(--aqua),#7fe3f2);border-radius:999px;transition:width .5s ease}
.calc-res small{color:#a9c3dc;font-size:.82rem}
.calc-res .consejo{margin-top:18px;background:rgba(255,255,255,.08);border-radius:12px;padding:14px 16px;font-size:.95rem;color:#e3f1fb}
.nota-calc{font-size:.8rem;color:var(--suave);margin-top:12px}

/* Consejos por espacio */
.espacios .tabs{justify-content:center;margin-bottom:26px}
.lista-tips{display:grid;grid-template-columns:repeat(2,1fr);gap:14px}
.tip{display:flex;gap:14px;background:#fff;border:1px solid var(--borde);border-radius:14px;padding:18px 20px}
.tip b{flex:0 0 34px;height:34px;border-radius:50%;background:var(--aqua-cl);color:var(--azul);display:grid;place-items:center;font-family:"Sora",sans-serif}
.tip p{color:var(--suave);font-size:.96rem}
.tip strong{color:var(--texto)}

/* Quiz */
.quiz{max-width:760px;margin:0 auto}
.pregunta{background:var(--fondo);border:1px solid var(--borde);border-radius:var(--radio);padding:22px 24px;margin-bottom:14px}
.pregunta h3{font-size:1.05rem}
.opciones{display:flex;gap:10px;margin-top:12px}
.opciones button{border:1px solid var(--borde);background:#fff;padding:9px 20px;border-radius:999px;font:600 .92rem "Karla",sans-serif;cursor:pointer;color:var(--texto)}
.opciones button:disabled{cursor:default}
.opciones button.bien{background:#e3f5ee;border-color:var(--ok);color:var(--ok)}
.opciones button.malo{background:#fbe9e7;border-color:var(--mal);color:var(--mal)}
.explica{margin-top:12px;color:var(--suave);font-size:.95rem;display:none}
.explica.ver{display:block;animation:aparece .4s ease}
.marcador{text-align:center;font-family:"Sora",sans-serif;color:var(--navy);margin-top:18px;font-weight:600}

.nota-final{background:#fff;border:1px solid var(--borde);border-left:5px solid var(--aqua);border-radius:var(--radio);padding:26px}
.nota-final p{color:var(--suave)}
.nota-final strong{color:var(--texto)}

/* Reveal */
.reveal{opacity:0;transform:translateY(26px);transition:opacity .8s ease,transform .8s ease}
.reveal.visible{opacity:1;transform:none}
@keyframes aparece{from{opacity:0;transform:translateY(6px)}to{opacity:1;transform:none}}

.subir{position:fixed;right:18px;bottom:18px;width:46px;height:46px;border-radius:50%;background:var(--navy);color:#fff;border:0;cursor:pointer;display:grid;place-items:center;opacity:0;pointer-events:none;transition:opacity .3s;z-index:30;box-shadow:0 8px 20px rgba(10,35,66,.25)}
.subir.ver{opacity:1;pointer-events:auto}

footer.site{background:var(--navy);color:#b9cde0;padding:48px 0 24px;font-size:.93rem}
footer.site .cols{display:grid;grid-template-columns:1.4fr 1fr 1fr;gap:28px}
footer.site h4{color:#fff;margin-bottom:10px;font-size:1rem;font-family:"Sora",sans-serif}
footer.site a{color:#b9cde0}
footer.site a:hover{color:#7fe3f2}
footer.site ul{list-style:none}
footer.site li+li{margin-top:6px}
.legal-bar{border-top:1px solid rgba(255,255,255,.12);margin-top:28px;padding-top:16px;font-size:.82rem;color:#8eaac4}

.legal{max-width:820px;margin:0 auto;padding:48px 20px 64px}
.legal h1{font-size:2rem;margin-bottom:6px}
.legal .fecha{color:var(--suave);font-size:.9rem;margin-bottom:28px}
.legal h2{font-size:1.2rem;margin:28px 0 8px;color:var(--azul)}
.legal p,.legal li{color:#33485e}
.legal ul{padding-left:22px;margin-top:8px}
.legal li+li{margin-top:4px}
.datos{background:#fff;border:1px solid var(--borde);border-radius:var(--radio);padding:18px 20px;margin-top:10px}

@media (max-width:900px){
  .stats .grid{grid-template-columns:1fr 1fr}
  .stat{padding:18px 16px}
  .stat .num{font-size:1.6rem}
  .stat p{font-size:.88rem}
  .dist,.ciclo,.cuerpo,.calc,.lista-tips,footer.site .cols{grid-template-columns:1fr}
  nav.menu{display:none}
  .hero{padding:56px 0 150px}
  section.bloque{padding:60px 0}
  .btn.sec{margin:10px 0 0}
}
@media (prefers-reduced-motion:reduce){
  *,*::before,*::after{animation:none!important;transition:none!important}
  .reveal{opacity:1;transform:none}
}
section[id]{scroll-margin-top:72px}