/* Formación Solar — design system (claro/escuro, mobile-first) */
:root{
  --bg:#faf8f3; --surface:#ffffff; --surface2:#f3efe6;
  --ink:#20293a; --ink-strong:#101828; --muted:#5b6474;
  --accent:#b45309; --accent-soft:#fde9c8; --sun:#f59e0b;
  --blue:#0e2a4f; --blue-ink:#0e2a4f; --link:#9a4207;
  --border:#e6e0d2; --code:#f4f0e6;
  --shadow:0 1px 2px rgba(16,24,40,.06),0 8px 24px -12px rgba(16,24,40,.12);
  --r:14px;
}
:root[data-theme="dark"]{
  --bg:#0c1320; --surface:#121b2b; --surface2:#0f1726;
  --ink:#dbe2ee; --ink-strong:#f2f5fa; --muted:#93a0b4;
  --accent:#fbbf24; --accent-soft:#2a2410; --sun:#fbbf24;
  --blue:#a9c4e8; --blue-ink:#cfdff5; --link:#f0b64a;
  --border:#233149; --code:#0f1a2c;
  --shadow:0 1px 2px rgba(0,0,0,.4),0 10px 30px -12px rgba(0,0,0,.55);
}
@media (prefers-color-scheme: dark){
  :root:not([data-theme="light"]){
    --bg:#0c1320; --surface:#121b2b; --surface2:#0f1726;
    --ink:#dbe2ee; --ink-strong:#f2f5fa; --muted:#93a0b4;
    --accent:#fbbf24; --accent-soft:#2a2410; --sun:#fbbf24;
    --blue:#a9c4e8; --blue-ink:#cfdff5; --link:#f0b64a;
    --border:#233149; --code:#0f1a2c;
    --shadow:0 1px 2px rgba(0,0,0,.4),0 10px 30px -12px rgba(0,0,0,.55);
  }
}
*{box-sizing:border-box}
html{-webkit-text-size-adjust:100%;scroll-behavior:smooth}
body{margin:0;background:var(--bg);color:var(--ink);font:400 1.0625rem/1.75 system-ui,-apple-system,"Segoe UI",Roboto,"Helvetica Neue",Arial,sans-serif;text-rendering:optimizeLegibility}
.wrap{max-width:1060px;margin:0 auto;padding:0 20px}
.skip{position:absolute;left:-999px;top:0;background:var(--accent);color:#fff;padding:.5rem 1rem;border-radius:0 0 8px 0;z-index:99}
.skip:focus{left:0}

/* ---------- header ---------- */
.site-head{background:var(--surface);border-bottom:1px solid var(--border);position:sticky;top:0;z-index:50;backdrop-filter:saturate(1.2) blur(6px)}
.head-row{display:flex;align-items:center;justify-content:space-between;gap:1rem;min-height:64px}
.brand{display:flex;align-items:center;gap:.6rem;text-decoration:none;color:var(--ink-strong)}
.brand-mark{width:30px;height:30px;flex:none}
.brand-name{font-weight:800;font-size:1.15rem;letter-spacing:-.01em}
.brand-name em{font-style:normal;color:var(--accent)}
.site-nav{display:flex;align-items:center;gap:.25rem;flex-wrap:wrap}
.site-nav a{color:var(--ink);text-decoration:none;font-weight:600;font-size:.95rem;padding:.45rem .65rem;border-radius:9px}
.site-nav a:hover{background:var(--surface2);color:var(--ink-strong)}
#theme-toggle{background:none;border:1px solid var(--border);color:var(--ink);border-radius:9px;padding:.3rem .55rem;font-size:1rem;cursor:pointer;line-height:1}
#theme-toggle:hover{background:var(--surface2)}

/* ---------- typography ---------- */
h1{font-size:clamp(1.85rem,4.5vw,2.6rem);line-height:1.15;letter-spacing:-.02em;color:var(--ink-strong);margin:.4em 0 .4em}
h2{font-size:clamp(1.35rem,3vw,1.7rem);line-height:1.25;letter-spacing:-.015em;color:var(--ink-strong);margin:2.2em 0 .5em}
h3{font-size:1.15rem;color:var(--ink-strong);margin:1.8em 0 .4em}
p{margin:.9em 0}
a{color:var(--link)}
a:hover{text-decoration-thickness:2px}
.lede{font-size:1.2rem;color:var(--muted);line-height:1.65;max-width:62ch}
article{max-width:72ch}
article img,article svg.diagram{max-width:100%;height:auto}
ul,ol{padding-left:1.4rem}
li{margin:.35em 0}
hr{border:0;border-top:1px solid var(--border);margin:2.5rem 0}
strong{color:var(--ink-strong)}
code{background:var(--code);border:1px solid var(--border);border-radius:6px;padding:.08em .35em;font-size:.92em}

.crumbs{font-size:.88rem;color:var(--muted);margin:1.2rem 0 0;display:flex;gap:.5rem;align-items:center}
.crumbs a{color:var(--muted)}

/* ---------- components ---------- */
.hero{padding:3.2rem 0 2.4rem}
.hero .lede{margin-top:.6rem}
.hero-grid{display:grid;grid-template-columns:1.25fr .75fr;gap:2.5rem;align-items:center}
@media(max-width:820px){.hero-grid{grid-template-columns:1fr}}
.btn{display:inline-block;background:var(--accent);color:#fff;text-decoration:none;font-weight:700;padding:.7rem 1.25rem;border-radius:11px;box-shadow:var(--shadow)}
:root[data-theme="dark"] .btn{color:#1a1305}
@media (prefers-color-scheme: dark){:root:not([data-theme="light"]) .btn{color:#1a1305}}
.btn:hover{filter:brightness(1.06);text-decoration:none}
.btn-ghost{display:inline-block;color:var(--ink-strong);text-decoration:none;font-weight:700;padding:.7rem 1.1rem;border:1px solid var(--border);border-radius:11px;margin-left:.5rem;background:var(--surface)}
.btn-ghost:hover{background:var(--surface2)}

.cards{display:grid;grid-template-columns:repeat(auto-fill,minmax(260px,1fr));gap:1rem;padding:0;margin:1.5rem 0;list-style:none}
.card{background:var(--surface);border:1px solid var(--border);border-radius:var(--r);padding:1.15rem 1.25rem;box-shadow:var(--shadow);display:flex;flex-direction:column;gap:.3rem}
.card a{color:var(--ink-strong);text-decoration:none;font-weight:750;font-size:1.05rem;letter-spacing:-.01em}
.card a::after{content:"";position:absolute;inset:0}
.card{position:relative}
.card:hover{border-color:var(--accent)}
.card p{margin:0;color:var(--muted);font-size:.94rem;line-height:1.55}
.card .tag{font-size:.75rem;font-weight:700;text-transform:uppercase;letter-spacing:.06em;color:var(--accent)}

.toc{background:var(--surface2);border:1px solid var(--border);border-radius:var(--r);padding:1rem 1.25rem;margin:1.5rem 0;font-size:.95rem}
.toc p{margin:0 0 .35rem;font-weight:750;color:var(--ink-strong)}
.toc ol{margin:0;padding-left:1.2rem}
.toc a{text-decoration:none}
.toc a:hover{text-decoration:underline}

.nota,.ojo{border:1px solid var(--border);border-left:4px solid var(--accent);background:var(--surface);border-radius:10px;padding:.85rem 1.1rem;margin:1.4rem 0;font-size:.98rem}
.ojo{border-left-color:#c2410c}
.nota .t,.ojo .t{font-weight:800;color:var(--accent);text-transform:uppercase;font-size:.78rem;letter-spacing:.07em;display:block;margin-bottom:.15rem}
.ojo .t{color:#c2410c}
:root[data-theme="dark"] .ojo .t{color:#fb923c}
@media (prefers-color-scheme: dark){:root:not([data-theme="light"]) .ojo .t{color:#fb923c}}

table{border-collapse:collapse;width:100%;margin:1.4rem 0;font-size:.95rem;background:var(--surface);border-radius:10px;overflow:hidden;box-shadow:var(--shadow)}
th{background:var(--surface2);color:var(--ink-strong);text-align:left;font-size:.85rem;text-transform:uppercase;letter-spacing:.04em}
th,td{padding:.6rem .8rem;border-bottom:1px solid var(--border)}
tr:last-child td{border-bottom:0}
.table-scroll{overflow-x:auto;margin:1.4rem 0}
.table-scroll table{margin:0;min-width:560px}

.diagram-box{background:var(--surface);border:1px solid var(--border);border-radius:var(--r);padding:1.25rem;margin:1.6rem 0;box-shadow:var(--shadow)}
.diagram-box figcaption{font-size:.88rem;color:var(--muted);margin-top:.6rem;text-align:center}

.file-list{list-style:none;padding:0;margin:1rem 0}
.file-list li{display:flex;gap:.7rem;align-items:baseline;padding:.55rem .2rem;border-bottom:1px dashed var(--border);margin:0}
.file-list .ext{flex:none;font-size:.7rem;font-weight:800;letter-spacing:.05em;color:var(--accent);border:1px solid var(--border);border-radius:6px;padding:.1rem .4rem;background:var(--surface)}
.file-list a{font-weight:600;text-decoration:none}
.file-list a:hover{text-decoration:underline}
.file-list .ctx{color:var(--muted);font-size:.88rem}

.faq details{border:1px solid var(--border);border-radius:10px;background:var(--surface);padding:.7rem 1rem;margin:.6rem 0}
.faq summary{font-weight:700;color:var(--ink-strong);cursor:pointer}
.faq p{margin:.6rem 0 .2rem}

.pill-row{display:flex;flex-wrap:wrap;gap:.45rem;margin:1rem 0}
.pill{font-size:.82rem;font-weight:700;border:1px solid var(--border);background:var(--surface);border-radius:99px;padding:.25rem .7rem;color:var(--muted)}

/* ---------- footer ---------- */
.site-foot{border-top:1px solid var(--border);background:var(--surface);margin-top:4rem}
.foot-grid{display:grid;grid-template-columns:1.2fr .9fr .9fr;gap:2rem;padding:2.2rem 20px}
@media(max-width:720px){.foot-grid{grid-template-columns:1fr}}
.foot-brand{font-weight:800;font-size:1.1rem;color:var(--ink-strong);margin:0 0 .4rem}
.foot-brand em{font-style:normal;color:var(--accent)}
.foot-note{color:var(--muted);font-size:.92rem;margin:0;max-width:34ch}
.foot-h{font-weight:800;font-size:.8rem;text-transform:uppercase;letter-spacing:.07em;color:var(--muted);margin:0 0 .5rem}
.site-foot nav a{display:block;color:var(--ink);text-decoration:none;font-size:.93rem;padding:.18rem 0}
.site-foot nav a:hover{color:var(--accent)}
.foot-legal{border-top:1px solid var(--border);padding:1rem 20px 1.4rem}
.foot-legal p{color:var(--muted);font-size:.85rem;margin:.6rem 0 0}
.foot-legal a{color:var(--muted)}

@media print{.site-head,.site-foot,#theme-toggle{display:none}}

/* a11y: foco visível consistente */
a:focus-visible,button:focus-visible,summary:focus-visible{outline:3px solid var(--accent);outline-offset:2px;border-radius:4px}