:root{
  --accent:#0F6CBD; --accent-d:#0C5AA6; --accent-l:#2886DE; --accent-soft:#EAF3FB;
  --ok:#107C41; --ok-soft:#E3F2E9; --warn:#9A6700; --warn-soft:#FFF8E6;
  --bg:#F5F7FA; --panel:#FFFFFF; --panel-2:#FBFCFE; --ink:#1A1D21; --ink-2:#4A5057; --ink-3:#646D77;
  --line:#E3E8EF; --line-2:#EDF1F6; --shadow:0 1px 3px rgba(16,24,40,.06),0 6px 24px rgba(16,24,40,.06);
  --shadow-lg:0 12px 48px rgba(16,24,40,.14); --radius:14px; --radius-s:10px;
  --mono:'IBM Plex Mono',ui-monospace,monospace; --sans:'IBM Plex Sans',-apple-system,system-ui,sans-serif;
}
*{box-sizing:border-box;margin:0;padding:0}
html,body{height:100%}
body{font-family:var(--sans);background:var(--bg);color:var(--ink);line-height:1.6;-webkit-font-smoothing:antialiased;font-size:16px}
.wrap{max-width:880px;margin:0 auto;padding:28px 20px 80px}
a{color:var(--accent)}
[data-lang="es"] [lang="en"],[data-lang="en"] [lang="es"]{display:none}

/* Header */
.topbar{display:flex;align-items:center;justify-content:space-between;gap:12px;margin-bottom:28px}
.brand{display:flex;align-items:center;gap:14px;text-decoration:none;color:inherit}
.brand .logo{width:44px;height:44px;flex-shrink:0;border-radius:11px;overflow:hidden}
.brand .logo img{display:block;width:100%;height:100%}
.brand .name{font-size:20px;font-weight:800;letter-spacing:-.02em;color:var(--ink)}
.toggle{display:flex;border:1px solid var(--line);border-radius:9px;overflow:hidden;background:var(--panel)}
.toggle button{padding:7px 12px;font-size:13px;font-weight:600;color:var(--ink-3);font-family:var(--mono);cursor:pointer;border:none;background:none}
.toggle button.on{background:var(--accent);color:#fff}

/* Breadcrumb */
.crumb{font-size:13px;color:var(--ink-3);margin-bottom:18px}
.crumb a{color:var(--ink-3);text-decoration:none}
.crumb a:hover{color:var(--accent)}

/* Hero */
.hero{background:var(--panel);border:1px solid var(--line);border-radius:var(--radius);box-shadow:var(--shadow);padding:40px 36px;text-align:center;margin-bottom:22px;position:relative;overflow:hidden}
.hero:before{content:"";position:absolute;inset:0;background:radial-gradient(900px 300px at 50% -40%,var(--accent-soft),transparent 70%);pointer-events:none}
.hero .eyebrow{font-family:var(--mono);font-size:12.5px;letter-spacing:.08em;color:var(--accent);font-weight:600;text-transform:uppercase;position:relative}
.hero h1{font-size:30px;font-weight:700;letter-spacing:-.02em;margin:10px 0 10px;position:relative}
.hero p{color:var(--ink-2);max-width:600px;margin:0 auto;font-size:15.5px;position:relative}
.hero .cta{margin-top:22px;position:relative}
.btn{display:inline-flex;align-items:center;justify-content:center;gap:8px;padding:13px 26px;border-radius:var(--radius-s);font-weight:600;font-size:15.5px;text-decoration:none;border:1px solid transparent;transition:.15s}
.btn-primary{background:var(--accent);color:#fff}
.btn-primary:hover{background:var(--accent-d);transform:translateY(-1px);box-shadow:var(--shadow)}

/* Stats */
.stats{display:flex;justify-content:center;gap:0;margin:26px 0 4px;flex-wrap:wrap;position:relative}
.stat{padding:0 26px;text-align:center;position:relative}
.stat + .stat:before{content:"";position:absolute;left:0;top:6px;bottom:6px;width:1px;background:var(--line)}
.stat .n{font-size:24px;font-weight:700;font-family:var(--mono);color:var(--ink)}
.stat .l{font-size:12px;color:var(--ink-3);text-transform:uppercase;letter-spacing:.05em;margin-top:2px}

/* Sections */
section.block{margin:30px 0}
section.block h2{font-size:22px;font-weight:700;letter-spacing:-.01em;margin-bottom:14px}
.card{background:var(--panel);border:1px solid var(--line);border-radius:var(--radius);box-shadow:var(--shadow);padding:22px 26px}

/* Domain table */
.dom-list{display:flex;flex-direction:column;gap:10px}
.dom-row{display:flex;align-items:center;justify-content:space-between;gap:14px;padding:12px 16px;border:1px solid var(--line);border-radius:var(--radius-s);background:var(--panel-2)}
.dom-row .dn{font-size:14.5px;color:var(--ink)}
.dom-row .dw{font-family:var(--mono);font-weight:700;color:var(--accent);font-size:13.5px;white-space:nowrap}

/* Why list */
.why-list{display:grid;grid-template-columns:repeat(auto-fit,minmax(220px,1fr));gap:14px}
.why-item{display:flex;gap:12px;align-items:flex-start;padding:16px;border:1px solid var(--line);border-radius:var(--radius-s);background:var(--panel)}
.why-item .wi{flex-shrink:0;width:32px;height:32px;border-radius:9px;display:grid;place-items:center;background:var(--accent-soft);color:var(--accent)}
.why-item .wt{font-size:14.5px;color:var(--ink-2);line-height:1.5}

/* FAQ */
.faq-item{border:1px solid var(--line);border-radius:var(--radius-s);background:var(--panel);padding:16px 18px;margin-bottom:10px}
.faq-item h3{font-size:15.5px;font-weight:600;margin-bottom:6px}
.faq-item p{color:var(--ink-2);font-size:14.5px}

/* Footer */
footer{margin-top:40px;padding-top:24px;border-top:1px solid var(--line);font-size:13.5px;color:var(--ink-3)}
footer .other-exams{display:flex;gap:14px;flex-wrap:wrap;margin-bottom:14px}
footer .other-exams a{text-decoration:none;font-weight:600}
footer .other-exams a:hover{text-decoration:underline}
footer .legal a{color:var(--ink-3);text-decoration:underline}

@media(max-width:560px){
  .hero{padding:28px 20px}
  .hero h1{font-size:24px}
  .stat{padding:0 16px}
}

/* ===== Visual polish ===== */
html[data-theme="dark"]{
  --accent:#4CA0E8; --accent-d:#3C8FD6; --accent-l:#69B4F2; --accent-soft:#16314B;
  --ok:#4FC07E; --ok-soft:#13301F; --warn:#E0B341; --warn-soft:#352B12;
  --bg:#0E1116; --panel:#171B22; --panel-2:#1C212A; --ink:#E8ECF1; --ink-2:#AEB6C0; --ink-3:#7C8593;
  --line:#262C36; --line-2:#20262F; --shadow:0 1px 3px rgba(0,0,0,.4),0 8px 28px rgba(0,0,0,.35);
  --shadow-lg:0 12px 48px rgba(0,0,0,.5);
}
.hero{background:linear-gradient(135deg,#0A4A9A 0%,#0F6CBD 55%,#2886DE 100%);border:0;color:#fff;box-shadow:0 16px 44px rgba(15,108,189,.28);padding:46px 38px}
html[data-theme="dark"] .hero{background:linear-gradient(135deg,#0B2540 0%,#12457A 60%,#1B5FA8 100%);box-shadow:0 16px 44px rgba(0,0,0,.45)}
.hero:before{background:radial-gradient(circle at 88% -10%,rgba(255,255,255,.22),rgba(255,255,255,0) 55%),radial-gradient(circle at 6% 120%,rgba(255,255,255,.14),rgba(255,255,255,0) 55%)}
.hero .eyebrow{display:inline-block;color:#fff;background:rgba(255,255,255,.16);border:1px solid rgba(255,255,255,.3);padding:5px 14px;border-radius:99px;letter-spacing:.06em}
.hero h1{color:#fff;font-size:32px;line-height:1.2;max-width:720px;margin-left:auto;margin-right:auto}
.hero p{color:rgba(255,255,255,.92)}
.hero .btn-primary{background:#fff;color:#0A4A9A;box-shadow:0 8px 22px rgba(0,0,0,.2);padding:14px 30px}
.hero .btn-primary:hover{background:#fff;transform:translateY(-2px);box-shadow:0 12px 28px rgba(0,0,0,.26)}
.hero .stats{gap:10px;margin-top:30px}
.hero .stat{padding:12px 22px;background:rgba(255,255,255,.12);border:1px solid rgba(255,255,255,.22);border-radius:14px;min-width:110px}
.hero .stat + .stat:before{display:none}
.hero .stat .n{color:#fff}
.hero .stat .l{color:rgba(255,255,255,.85)}
.dom-row{flex-wrap:wrap;transition:border-color .2s,transform .2s}
.dom-row:hover{border-color:var(--accent);transform:translateX(2px)}
.dom-row .dn{flex:1 1 280px}
.dom-row .dbar{flex:0 0 120px;height:7px;border-radius:99px;background:var(--line-2);overflow:hidden}
.dom-row .dbar i{display:block;height:100%;border-radius:99px;background:linear-gradient(90deg,var(--accent),var(--accent-l))}
.why-item{transition:transform .2s,box-shadow .2s,border-color .2s}
.why-item:hover{transform:translateY(-2px);box-shadow:var(--shadow);border-color:var(--accent)}
.faq-item{border-left:3px solid var(--accent)}
footer .other-exams{gap:8px}
footer .other-exams a{padding:7px 13px;border:1px solid var(--line);border-radius:99px;background:var(--panel);font-size:13px;color:var(--ink-2);font-weight:500;transition:border-color .15s,color .15s}
footer .other-exams a:hover{border-color:var(--accent);color:var(--accent);text-decoration:none}
.sticky-cta{position:fixed;left:0;right:0;bottom:0;z-index:50;padding:10px 16px calc(10px + env(safe-area-inset-bottom));background:var(--panel);border-top:1px solid var(--line);box-shadow:0 -8px 24px rgba(16,24,40,.12);transform:translateY(110%);transition:transform .25s;display:none}
.sticky-cta.show{transform:none}
.sticky-cta .btn{width:100%;padding:13px 18px}
@media(max-width:700px){.sticky-cta{display:block}.wrap{padding-bottom:110px}.hero .stat{min-width:0;flex:1 1 40%;padding:10px 12px}.hero{padding:34px 20px}.hero h1{font-size:25px}.dom-row .dbar{flex:1 1 100%}}
@media(prefers-reduced-motion:reduce){.dom-row,.why-item,.sticky-cta{transition:none}}
html[data-lang="en"] .hero .eyebrow[lang="es"],html[data-lang="es"] .hero .eyebrow[lang="en"]{display:none}
html[data-theme="dark"] .toggle button.on,html[data-theme="dark"] .btn-primary{color:#04121F}
/* language links (separate ES/EN URLs) */
.toggle a{padding:7px 12px;font-size:13px;font-weight:600;color:var(--ink-3);font-family:var(--mono);text-decoration:none}
.toggle a.on{background:var(--accent);color:#fff}
.toggle a:hover:not(.on){color:var(--accent)}
/* sample questions */
.samples .sq-intro{color:var(--ink-2);font-size:14.5px;margin:-4px 0 14px}
.sq{border:1px solid var(--line);border-radius:var(--radius-s);background:var(--panel);padding:16px 18px;margin-bottom:12px}
.sq-q{font-weight:600;font-size:15px;line-height:1.5;margin-bottom:10px}
.sq-n{font-family:var(--mono);color:var(--accent);margin-right:2px}
.sq-opts{margin:0 0 10px 22px;padding:0;color:var(--ink-2);font-size:14.5px}
.sq-opts li{margin:4px 0;padding-left:4px}
.sq-ans summary{cursor:pointer;font-weight:600;color:var(--accent);font-size:14px;list-style:revert}
.sq-ans p{margin-top:8px;color:var(--ink-2);font-size:14.5px;background:var(--ok-soft);border-radius:8px;padding:10px 12px}
.sq-ans p strong{color:var(--ok)}
.sq-cta{text-align:center;margin-top:16px}
/* English hub */
.hub-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(260px,1fr));gap:12px}
.hub-card{display:flex;flex-direction:column;gap:6px;padding:16px 18px;border:1px solid var(--line);border-radius:var(--radius-s);background:var(--panel);text-decoration:none;color:var(--ink);transition:.15s}
.hub-card:hover{border-color:var(--accent);box-shadow:var(--shadow);transform:translateY(-1px)}
.hub-code{font-family:var(--mono);font-weight:700;color:var(--accent);font-size:13px}
.hub-title{font-weight:700;font-size:15.5px;line-height:1.3}
.hub-desc{color:var(--ink-2);font-size:13.5px;line-height:1.45}
.hub-meta{margin-top:auto;font-size:12px;color:var(--ink-3);text-transform:uppercase;letter-spacing:.04em}
.hub-ret{color:#c2410c}
[data-theme="dark"] .sq-ans p{background:rgba(16,124,65,.15)}
/* category pages */
.prose p{color:var(--ink-2);font-size:15.5px;line-height:1.7;margin-bottom:12px}
.prose h2{margin-bottom:10px}
.hub-cats{display:flex;flex-wrap:wrap;gap:10px}
.hub-cat{padding:10px 16px;border:1px solid var(--line);border-radius:99px;background:var(--panel);text-decoration:none;font-weight:600;color:var(--accent)}
.hub-cat:hover{border-color:var(--accent);box-shadow:var(--shadow)}
footer .cat-links{margin-top:-4px}
footer .other-exams span{color:var(--ink-3);font-weight:600}