*,*::before,*::after{margin:0;padding:0;box-sizing:border-box}
:root{
  --azul:#1F4E79;
  --azul-desc:#3B82C4;
  --niebla:#EBF3FB;
  --tierra:#A0714F;
  --gris:#6B7280;
  --negro:#1A1A1A;
  --blanco:#FFFFFF;
  --fondo:#FDFAF7;
  --borde:rgba(0,0,0,0.08);
  --serif:'Playfair Display',Georgia,serif;
  --sans:'Jost',Arial,sans-serif;
}
html{font-size:16px;scroll-behavior:smooth}
body{font-family:var(--sans);background:var(--fondo);color:var(--negro);line-height:1.7;font-weight:300}
a{color:inherit;text-decoration:none}
img{max-width:100%;display:block}

/* NAV */
.nav{position:fixed;top:0;left:0;right:0;z-index:100;background:rgba(253,250,247,0.96);backdrop-filter:blur(8px);border-bottom:.5px solid var(--borde);padding:0 48px;display:flex;align-items:center;justify-content:space-between;height:52px}
.nav-logo{display:flex;align-items:center}
.nav-logo-img{height:46px;width:auto;display:block}
.nav-links{display:flex;align-items:center;gap:28px;list-style:none}
.nav-links a{font-size:10px;font-weight:500;letter-spacing:.1em;text-transform:uppercase;color:var(--gris);transition:color .2s}
.nav-links a:hover{color:var(--azul)}
.nav-links a.active{color:var(--azul)}
.nav-cta{color:var(--azul) !important;border:.5px solid var(--azul);padding:5px 14px;border-radius:3px;transition:all .2s !important}
.nav-cta:hover{background:var(--azul);color:var(--blanco) !important}
.nav-burger{display:none;flex-direction:column;gap:5px;cursor:pointer;padding:4px}
.nav-burger span{display:block;width:20px;height:1px;background:var(--negro)}
.progress-bar{position:fixed;top:52px;left:0;z-index:99;height:2px;background:var(--azul-desc);width:0%;transition:width .1s linear;opacity:.8}

/* HERO LIBRO — dividido en dos columnas */
.libro-hero{
  min-height:100vh;
  display:grid;
  grid-template-columns:1fr 420px;
  padding-top:52px;
}
.libro-hero-left{
  background:var(--azul);
  padding:80px 72px 80px 96px;
  display:flex;flex-direction:column;justify-content:flex-end;
  position:relative;overflow:hidden;
}
.libro-hero-left::before{content:'';position:absolute;left:48px;top:72px;bottom:72px;width:1.5px;background:rgba(255,255,255,.15)}
.libro-hero-label{font-size:9px;font-weight:500;color:rgba(255,255,255,.45);letter-spacing:.22em;text-transform:uppercase;margin-bottom:20px}
.libro-hero-title{font-family:var(--serif);font-size:clamp(36px,3.5vw,52px);font-weight:400;color:var(--blanco);line-height:1.08;margin-bottom:16px}
.libro-hero-title em{font-style:italic;color:rgba(255,255,255,.65)}
.libro-hero-sep{display:flex;align-items:center;width:80px;margin-bottom:20px}
.libro-hero-sep-line{flex:1;height:.5px;background:rgba(255,255,255,.25)}
.libro-hero-sep-dot{width:4px;height:4px;border-radius:50%;background:rgba(255,255,255,.7);margin:0 8px;flex-shrink:0}
.libro-hero-sub{font-size:14px;font-weight:300;color:rgba(255,255,255,.55);max-width:480px;line-height:1.85;margin-bottom:40px}
.libro-hero-sub strong{color:rgba(255,255,255,.85);font-weight:400}

/* PORTADA PLACEHOLDER */
.libro-hero-right{
  background:var(--negro);
  display:flex;align-items:center;justify-content:center;
  padding:48px;
  position:relative;overflow:hidden;
}
.libro-hero-right::before{content:'';position:absolute;inset:0;background:linear-gradient(135deg,rgba(255,255,255,.03) 0%,transparent 60%)}
.libro-portada{
  width:100%;
  max-width:280px;
  aspect-ratio:2/3;
  background:rgba(255,255,255,.06);
  border:.5px solid rgba(255,255,255,.12);
  border-radius:8px;
  display:flex;flex-direction:column;
  align-items:center;justify-content:center;
  padding:2rem;text-align:center;
  position:relative;
}
.libro-portada img.portada-real{
  width:100%;height:100%;
  object-fit:cover;
  position:absolute;inset:0;
  border-radius:8px;
}
.libro-portada-atomo{
  width:64px;height:64px;
  margin-bottom:24px;
  opacity:.4;
}
.libro-portada-title{font-family:var(--serif);font-size:20px;font-weight:400;color:var(--blanco);line-height:1.3;margin-bottom:8px}
.libro-portada-sep{width:24px;height:.5px;background:rgba(255,255,255,.3);margin:0 auto 8px}
.libro-portada-author{font-size:10px;font-weight:400;letter-spacing:.1em;text-transform:uppercase;color:rgba(255,255,255,.35)}

/* LAYOUT */
.main{max-width:1100px;margin:0 auto;padding:80px 48px}
.section{margin-bottom:72px}
.sep{display:flex;align-items:center;margin:48px 0}
.sep-line{flex:1;height:.5px;background:var(--borde);transform:scaleX(0);transform-origin:left;transition:transform .8s ease}
.sep.visible .sep-line{transform:scaleX(1)}
.sep-dot{width:5px;height:5px;border-radius:50%;background:var(--azul);margin:0 10px;flex-shrink:0;opacity:0;transition:opacity .3s ease .7s}
.sep.visible .sep-dot{opacity:1}
p{font-size:14px;font-weight:300;color:var(--gris);line-height:1.85;max-width:none;margin-bottom:16px}
p strong{color:var(--negro);font-weight:500}
.chapter-label{font-size:9px;font-weight:500;color:var(--azul-desc);letter-spacing:.2em;text-transform:uppercase;margin-bottom:8px;padding-bottom:8px;border-bottom:.5px solid var(--borde)}
.chapter-title{font-family:var(--serif);font-size:clamp(28px,3vw,38px);font-weight:400;color:var(--negro);line-height:1.1;margin-bottom:12px}
.chapter-title em{font-style:italic}

/* PULLQUOTES */
.pullquote{border-left:2px solid var(--azul);padding:4px 0 4px 20px;margin:28px 0}
.pullquote-text{font-family:var(--serif);font-size:22px;font-style:italic;font-weight:400;color:var(--azul);line-height:1.5;margin:0}
.pullquote-source{font-size:11px;color:var(--gris);letter-spacing:.06em;margin-top:8px}

/* FRAGMENTOS */
.fragmentos{display:flex;flex-direction:column;gap:1px;background:var(--borde);border:.5px solid var(--borde);border-radius:10px;overflow:hidden;margin-top:24px}
.fragmento{background:var(--blanco);padding:28px 32px;border-left:4px solid transparent;transition:background .2s}
.fragmento:hover{background:#F8F8F6}
.fragmento:nth-child(1){border-left-color:#1F4E79}
.fragmento:nth-child(2){border-left-color:#3B82C4}
.fragmento:nth-child(3){border-left-color:#A0714F}
.fragmento-texto{font-family:var(--serif);font-size:19px;font-style:italic;color:var(--negro);line-height:1.6;margin-bottom:8px}
.fragmento-ref{font-size:10px;font-weight:500;letter-spacing:.1em;text-transform:uppercase;color:var(--gris)}

/* SECCIONES DEL LIBRO */
.secciones{display:flex;flex-direction:column}
.seccion-item{
  display:grid;grid-template-columns:80px 1fr;gap:1.5rem;
  padding:20px 0;border-bottom:.5px solid var(--borde);
  align-items:start;transition:background .2s;
}
.seccion-item:first-child{border-top:.5px solid var(--borde)}
.seccion-item:hover{background:rgba(31,78,121,.03)}
.seccion-roman{
  font-family:var(--serif);font-size:32px;font-weight:400;
  color:var(--azul);line-height:1;padding-top:4px;
}
.seccion-title{font-size:14px;font-weight:500;color:var(--negro);margin-bottom:4px}
.seccion-desc{font-size:13px;font-weight:300;color:var(--gris);line-height:1.7;margin:0}

/* CTA NEGRO */
.libro-cta{
  background:var(--azul);
  border-radius:10px;
  padding:48px 52px;
  display:grid;grid-template-columns:1fr auto;
  gap:3rem;align-items:center;
  position:relative;overflow:hidden;
}
.libro-cta::before{content:'';position:absolute;left:24px;top:32px;bottom:32px;width:1.5px;background:rgba(255,255,255,.1)}
.libro-cta-text{font-family:var(--serif);font-size:22px;font-style:italic;color:rgba(255,255,255,.85);line-height:1.5}
.libro-cta-sub{font-size:13px;font-weight:300;color:rgba(255,255,255,.45);line-height:1.7;margin-top:8px}
.btn{display:inline-flex;align-items:center;gap:8px;padding:12px 24px;border-radius:4px;font-family:var(--sans);font-size:10px;font-weight:500;letter-spacing:.1em;text-transform:uppercase;cursor:pointer;border:none;transition:all .25s;white-space:nowrap}
.btn::after{content:'→';display:inline-block;transition:transform .3s ease}
.btn:hover::after{transform:translateX(5px)}
.btn-blanco{background:var(--blanco);color:var(--azul)}
.btn-blanco:hover{background:var(--niebla);transform:translateY(-1px)}

/* FADE */
.fade-up{opacity:0;transform:translateY(20px);transition:opacity .7s ease,transform .7s ease}
.fade-up.visible{opacity:1;transform:translateY(0)}

/* BTN HERO */
.btn-ghost-white{display:inline-flex;align-items:center;gap:8px;padding:10px 22px;border-radius:3px;font-family:var(--sans);font-size:10px;font-weight:500;letter-spacing:.1em;text-transform:uppercase;background:transparent;color:rgba(255,255,255,.6);border:.5px solid rgba(255,255,255,.2);transition:all .2s;cursor:pointer}
.btn-ghost-white:hover{border-color:rgba(255,255,255,.5);color:var(--blanco);transform:translateY(-1px)}
.btn-primary-white{display:inline-flex;align-items:center;gap:8px;padding:10px 22px;border-radius:3px;font-family:var(--sans);font-size:10px;font-weight:500;letter-spacing:.1em;text-transform:uppercase;background:var(--blanco);color:var(--azul);border:none;transition:all .2s;cursor:pointer}
.btn-primary-white:hover{background:var(--niebla);transform:translateY(-1px)}

/* FOOTER */
.footer{background:var(--negro);padding:48px;display:flex;justify-content:space-between;align-items:center;flex-wrap:wrap;gap:24px}
.footer-logo{display:flex;flex-direction:column;gap:6px}
.footer-logo-img{height:56px;width:auto;opacity:.9}
.footer-logo span{font-family:var(--sans);font-size:8px;letter-spacing:.18em;text-transform:uppercase;color:rgba(255,255,255,.25)}
.footer-links{display:flex;gap:24px;list-style:none;flex-wrap:wrap}
.footer-links a{font-size:10px;letter-spacing:.08em;text-transform:uppercase;color:rgba(255,255,255,.32);transition:color .2s}
.footer-links a:hover{color:rgba(255,255,255,.75)}
.footer-meta{font-size:9px;color:rgba(255,255,255,.18);letter-spacing:.06em}

/* RESPONSIVE */
@media(max-width:900px){
  .nav{padding:0 24px}
  .libro-hero{grid-template-columns:1fr;min-height:auto}
  .libro-hero-left{padding:100px 48px 56px}
  .libro-hero-left::before{left:24px}
  .libro-hero-right{min-height:420px;padding:48px}
  .main{padding:56px 32px}
  .libro-cta{grid-template-columns:1fr;gap:24px;padding:36px}
  .footer{padding:36px}
}
@media(max-width:640px){
  .nav{padding:0 20px}
  .nav-links{display:none}
  .nav-links.open{display:flex;flex-direction:column;position:absolute;top:52px;left:0;right:0;background:rgba(253,250,247,.98);border-bottom:.5px solid var(--borde);padding:20px 24px;gap:16px}
  .nav-burger{display:flex}
  .libro-hero-left{padding:80px 24px 48px;padding-left:52px}
  .main{padding:48px 20px}
  .seccion-item{grid-template-columns:56px 1fr}
  .seccion-roman{font-size:24px}
  .libro-cta{padding:28px 24px}
  .footer{padding:32px 24px;flex-direction:column;align-items:flex-start}
}


/* Ocultar fondo y borde del placeholder cuando hay imagen real */
.libro-portada img.portada-real{border-radius:8px;background:transparent}
.libro-portada:has(img.portada-real){background:transparent;border-color:transparent}