:root{--p:#1a5276;--pd:#154360;--s:#2980b9;--a:#e67e22;--g:#27ae60;--bg:#f4f6f8;--card:#fff;--text:#2c3e50;--tl:#5d6d7e;--b:#dce4ec;--sh:0 4px 20px rgba(0,0,0,0.08);--shh:0 8px 30px rgba(0,0,0,0.12);--r:12px;--rs:8px}
*{box-sizing:border-box;margin:0;padding:0}
html{scroll-behavior:smooth}
body{font-family:'Segoe UI',system-ui,sans-serif;background:var(--bg);color:var(--text);line-height:1.7;min-height:100vh}
.site-header{background:linear-gradient(135deg,var(--p),var(--pd));color:#fff;padding:1.2rem 2rem;position:sticky;top:0;z-index:100;box-shadow:0 2px 15px rgba(0,0,0,0.15)}
.site-header .container{max-width:1200px;margin:0 auto;display:flex;align-items:center;justify-content:space-between;flex-wrap:wrap;gap:1rem}
.site-title{font-size:1.4rem;font-weight:800;display:flex;align-items:center;gap:0.5rem}
.site-subtitle{font-size:0.85rem;opacity:0.9;font-weight:400}
.nav-links{display:flex;gap:0.8rem;list-style:none;flex-wrap:wrap}
.nav-links a{color:#fff;text-decoration:none;font-weight:500;padding:0.4rem 0.8rem;border-radius:var(--rs);transition:background 0.2s}
.nav-links a:hover,.nav-links a.active{background:rgba(255,255,255,0.2)}
.breadcrumb{background:#fff;border-bottom:1px solid var(--b);padding:0.8rem 2rem;font-size:0.9rem}
.breadcrumb .container{max-width:1200px;margin:0 auto}
.breadcrumb a{color:var(--s);text-decoration:none}
.breadcrumb a:hover{text-decoration:underline}
.breadcrumb span{color:var(--tl)}
.container{max-width:1200px;margin:0 auto;padding:2rem}
.page-title{font-size:2.2rem;font-weight:800;margin-bottom:0.5rem;color:var(--p)}
.page-subtitle{font-size:1.1rem;color:var(--tl);margin-bottom:2rem}
.card-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(300px,1fr));gap:1.5rem;margin-top:1.5rem}
.card{background:var(--card);border-radius:var(--r);padding:1.5rem;box-shadow:var(--sh);transition:all 0.3s;border:1px solid var(--b);text-decoration:none;color:inherit;display:flex;flex-direction:column;gap:0.5rem}
.card:hover{transform:translateY(-4px);box-shadow:var(--shh);border-color:var(--s)}
.card-icon{font-size:2.5rem;margin-bottom:0.3rem}
.card-title{font-size:1.2rem;font-weight:700;color:var(--p)}
.card-desc{font-size:0.95rem;color:var(--tl);flex:1}
.card-meta{font-size:0.8rem;color:var(--tl);background:var(--bg);padding:0.3rem 0.6rem;border-radius:var(--rs);display:inline-block;margin-top:0.5rem}
.card-badge{font-size:0.75rem;font-weight:700;padding:0.2rem 0.6rem;border-radius:20px;text-transform:uppercase}
.badge-4to{background:#e8f4f8;color:var(--s)}
.badge-5to{background:#fdf2e9;color:var(--a)}
.badge-primaria{background:#fef3c7;color:#c2410c}
.hero{background:linear-gradient(135deg,var(--p),var(--s));color:#fff;padding:3rem 2rem;text-align:center;margin-bottom:2rem}
.hero h1{font-size:2.5rem;font-weight:800;margin-bottom:0.5rem}
.hero p{font-size:1.1rem;opacity:0.9;max-width:700px;margin:0 auto}
.hero .badge{display:inline-block;background:rgba(255,255,255,0.2);padding:0.4rem 1rem;border-radius:20px;margin-top:1rem;font-size:0.9rem}
.book-container{max-width:900px;margin:0 auto;background:#fff;border-radius:var(--r);box-shadow:var(--sh);overflow:hidden}
.book-header{background:linear-gradient(135deg,var(--p),var(--pd));color:#fff;padding:2.5rem}
.book-header h1{font-size:1.8rem;font-weight:800}
.book-header .meta{display:flex;gap:1rem;margin-top:1rem;flex-wrap:wrap}
.book-header .meta span{background:rgba(255,255,255,0.2);padding:0.3rem 0.8rem;border-radius:20px;font-size:0.85rem}
.book-body{padding:2rem}
.book-body h2{color:var(--p);font-size:1.5rem;margin:2rem 0 1rem;padding-bottom:0.4rem;border-bottom:2px solid var(--b)}
.book-body h3{color:var(--s);font-size:1.25rem;margin:1.5rem 0 0.8rem}
.book-body h4{color:var(--text);font-size:1.1rem;margin:1.2rem 0 0.6rem;font-weight:600}
.book-body p{margin-bottom:1rem;text-align:justify}
.book-body ul,.book-body ol{margin:0.8rem 0 0.8rem 1.5rem}
.book-body li{margin-bottom:0.5rem}
.book-body table{width:100%;border-collapse:collapse;margin:1rem 0;font-size:0.9rem}
.book-body th,.book-body td{border:1px solid var(--b);padding:0.6rem;text-align:left}
.book-body th{background:var(--p);color:#fff;font-weight:600}
.book-body tr:nth-child(even){background:#f8f9fa}
.book-body blockquote{border-left:4px solid var(--a);margin:1rem 0;padding:0.8rem 1rem;background:#fdf2e9;font-style:italic}
.book-body pre{background:#f4f4f4;padding:1rem;border-radius:var(--rs);overflow-x:auto;font-family:monospace;font-size:0.9rem;margin:1rem 0}
.unidades-nav{display:flex;gap:0.5rem;flex-wrap:wrap;margin:1.5rem 0;padding:1rem;background:var(--bg);border-radius:var(--r)}
.unidades-nav a{padding:0.5rem 1rem;background:#fff;border:1px solid var(--b);border-radius:var(--rs);text-decoration:none;color:var(--text);font-size:0.9rem;font-weight:500;transition:all 0.2s}
.unidades-nav a:hover,.unidades-nav a.active{background:var(--s);color:#fff;border-color:var(--s)}
.competencia-box{background:#e8f4f8;border-left:4px solid var(--s);padding:1rem;margin:1rem 0;border-radius:0 var(--rs) var(--rs) 0}
.indicador-item{background:#f8f9fa;padding:0.6rem 1rem;margin:0.4rem 0;border-radius:var(--rs);border-left:3px solid var(--a)}
.contenido-item{background:#fff;padding:0.6rem 1rem;margin:0.4rem 0;border-radius:var(--rs);border:1px solid var(--b)}
.ejemplo-box{background:#fff;border:2px solid var(--s);border-radius:var(--r);padding:1.5rem;margin:1.5rem 0}
.ejemplo-box h4{color:var(--s);margin-bottom:0.8rem;font-size:1.1rem}
.solucion{background:#f8f9fa;padding:1rem;border-radius:var(--rs);margin-top:0.8rem}
.ejercicio-item{background:#fff;border:1px solid var(--b);border-radius:var(--r);padding:1.2rem;margin:1rem 0}
.ejercicio-item .respuesta{color:var(--g);margin-top:0.5rem;font-weight:500}
.caso-box{background:#fff;border:2px solid var(--a);border-radius:var(--r);padding:1.5rem;margin:1.5rem 0}
.caso-box h4{color:var(--a);margin-bottom:0.8rem}
.footer-nav{display:flex;justify-content:space-between;margin-top:2rem;padding-top:1rem;border-top:1px solid var(--b)}
.footer-nav a{padding:0.6rem 1.2rem;background:var(--p);color:#fff;text-decoration:none;border-radius:var(--rs);font-weight:500;transition:background 0.2s}
.footer-nav a:hover{background:var(--pd)}
.site-footer{background:var(--pd);color:#fff;padding:2rem;text-align:center;margin-top:3rem}
.site-footer p{opacity:0.8;font-size:0.9rem}
.fuente-box{background:#f0f7ff;border:1px solid #b3d9ff;border-radius:8px;padding:1rem;margin:1rem 0;font-size:0.9rem}
.fuente-box h4{color:#0066cc;margin-bottom:0.5rem}
.componente-box{background:#f0f8ff;border-left:4px solid #4a90d9;padding:1rem;margin:1rem 0;border-radius:0 var(--rs) var(--rs) 0}
.advertencia-box{background:#fff3cd;border:1px solid #ffc107;border-radius:8px;padding:1rem;margin:1rem 0;font-size:0.9rem;color:#856404}
.ilustracion-box{position:relative;overflow:hidden;background:linear-gradient(135deg,#0f172a,#1e293b);border-radius:var(--r);margin:1.5rem 0;border:1px solid rgba(255,255,255,0.08);min-height:260px}
.ilustracion-canvas{display:block;width:100%;height:auto;opacity:0;transition:opacity .35s ease}
.ilustracion-box.is-ready .ilustracion-canvas{opacity:1}
.ilustracion-loading{position:absolute;inset:0;display:grid;place-items:center;color:#cbd5e1;font-size:0.95rem;letter-spacing:.02em}
.ilustracion-box.is-ready .ilustracion-loading{display:none}
.ilustracion-overlay{position:absolute;left:0;right:0;bottom:0;padding:1rem 1.2rem;background:linear-gradient(180deg,transparent,rgba(15,23,42,.88));color:#fff}
.ilustracion-overlay h3{font-size:1rem;margin:0 0 .25rem;color:#fff}
.ilustracion-overlay p{margin:0;font-size:.88rem;opacity:.9}
@media(max-width:768px){.site-header .container{flex-direction:column;text-align:center}.nav-links{gap:0.8rem}.card-grid{grid-template-columns:1fr}.hero h1{font-size:1.8rem}.container{padding:1rem}.book-header{padding:1.5rem}.book-body{padding:1.2rem}}

/* —— Estilos libro CNB ampliado (4 unidades) —— */
body.cnb-book{background:#f4f6f8;color:#2c3e50;max-width:920px;margin:0 auto;padding:1.5rem 1.25rem 3rem}
.cnb-book .book-header{background:linear-gradient(135deg,#1a5276,#154360);color:#fff;padding:2rem 1.75rem;border-radius:12px;margin-bottom:1.25rem;box-shadow:0 4px 20px rgba(0,0,0,.08)}
.cnb-book .book-header .eyebrow{opacity:.85;font-size:.9rem;margin-bottom:.35rem}
.cnb-book .book-header h1{font-size:1.85rem;font-weight:800;margin:0 0 .5rem;color:#fff;border:0;padding:0}
.cnb-book .book-header .meta{opacity:.95;margin:0}
.cnb-book .book-toc{background:#fff;border:1px solid #dce4ec;border-radius:12px;padding:1.25rem 1.5rem;margin-bottom:1.5rem;box-shadow:0 4px 20px rgba(0,0,0,.06)}
.cnb-book .book-toc ol{margin:.5rem 0 0 1.25rem}
.cnb-book .book-toc a{color:#2980b9;text-decoration:none;font-weight:600}
.cnb-book .book-toc a:hover{text-decoration:underline}
.cnb-book .book-main{display:flex;flex-direction:column;gap:1.5rem}
.cnb-book article.unit{background:#fff;border:1px solid #dce4ec;border-radius:12px;padding:1.5rem 1.75rem 2rem;box-shadow:0 4px 20px rgba(0,0,0,.06)}
.cnb-book .unit-header{margin-bottom:1rem;padding-bottom:.75rem;border-bottom:2px solid #dce4ec}
.cnb-book .unit-eyebrow{color:#5d6d7e;font-size:.9rem;margin:0 0 .35rem}
.cnb-book .unit-title{color:#1a5276;font-size:1.45rem;margin:0;border:0;padding:0}
.cnb-book .unit-body,.cnb-book .content-body{line-height:1.75}
.cnb-book .unit-body h2,.cnb-book .unit-body h3{color:#1a5276;margin:1.5rem 0 .6rem}
.cnb-book .unit-body h4{color:#2980b9;margin:1.1rem 0 .45rem}
.cnb-book .unit-body p{margin-bottom:1rem;text-align:justify}
.cnb-book .unit-body ul,.cnb-book .unit-body ol{margin:0 0 1rem 1.4rem}
.cnb-book .unit-body li{margin-bottom:.4rem}
.cnb-book .expand-block{margin:1.25rem 0;padding:1rem 0;border-top:1px solid #e2e8f0}
.cnb-book .chapter-block{margin:1.5rem 0;padding-bottom:1rem;border-bottom:1px dashed #cbd5e1}
.cnb-book .model-box{background:#f8fafc;border:1px solid #cbd5e1;border-radius:8px;padding:1rem;white-space:pre-wrap;font-family:inherit;margin:1rem 0}
.cnb-book .exercise-item{background:#f0fdfa;border-left:4px solid #14b8a6;padding:.75rem 1rem;margin:.75rem 0;border-radius:0 8px 8px 0}
.cnb-book .exercise-badge{display:inline-block;font-size:.75rem;font-weight:700;color:#0f766e;margin-bottom:.35rem}
.cnb-book .guatemala-case{background:#eff6ff;border-radius:12px;padding:1rem;margin:1rem 0}
.cnb-book .definition-box{background:#fef3c7;border-left:4px solid #f59e0b;padding:.75rem 1rem;margin:1rem 0}
.cnb-book .interactive-lab{margin:1.25rem 0}
@media(max-width:768px){body.cnb-book{padding:1rem}.cnb-book .book-header h1{font-size:1.4rem}.cnb-book article.unit{padding:1.1rem}}