/* 2026-10-15 Web-1 (dueño, comentario 8958132b: "rediseña AxoPrep para que el diseño matchee la original y déjalo como sección").
   Tema de theibaxolotl.com para la copia de AxoPrep en /practice/: fondo negro, superficies grises, rosa del ajolote, botones azules
   redondos, Inter y Silkscreen. construir-web.mjs lo copia como practice/tema-ibaxo.css y lo enlaza en cada página después de styles.css. */
:root, :root:not(#x) {
  --brand: #ff6fae; --brand-ink: #000; --accent: #2997ff; --bg: #000; --surface: #1d1d1f; --ink: #f5f5f7;
  --muted: #a1a1a6; --line: #38383b; --good: #30d158; --mid: #ffd60a; --low: #ff453a; --radius: 18px; --shadow: none;
  --btn: #0071e3; color-scheme: dark;
}
body { background: #000; color: var(--ink); font: 17px/1.47 Inter, -apple-system, BlinkMacSystemFont, "SF Pro Text", "Helvetica Neue", Arial, sans-serif; letter-spacing: -.022em; -webkit-font-smoothing: antialiased; }
a { color: var(--accent); text-decoration: none; } a:hover { text-decoration: underline; }
h1 { font-size: clamp(2rem, 5vw, 3.2rem); letter-spacing: -.03em; line-height: 1.08; font-weight: 700; }
h2 { letter-spacing: -.02em; }

/* barra global del sitio (la misma de la web) + barra local de Practice, como en la web */
.ibx { background: rgba(17,17,18,.92); border-bottom: 1px solid var(--line); }
.ibx > div { max-width: 1080px; margin: 0 auto; padding: 0 16px; height: 44px; display: flex; align-items: center; gap: 22px; }
.ibx .logo { display: flex; align-items: center; gap: 8px; color: var(--ink); font-family: Silkscreen, monospace; font-size: .85rem; white-space: nowrap; }
.ibx .logo:hover { text-decoration: none; } .ibx .logo img { width: 24px; height: 24px; image-rendering: pixelated; } .ibx .logo b { color: var(--brand); font-weight: 400; }
.ibx nav { display: flex; gap: 22px; margin-left: auto; } .ibx nav a { color: #d2d2d7; font-size: .78rem; white-space: nowrap; } .ibx nav a:hover { color: #fff; text-decoration: none; }
.ibx nav a.on { color: var(--brand); font-weight: 600; }
.top { background: rgba(0,0,0,.78); backdrop-filter: saturate(180%) blur(20px); -webkit-backdrop-filter: saturate(180%) blur(20px); border-bottom: 1px solid var(--line); padding-top: .45rem; padding-bottom: .45rem; }
.brand { font-family: Silkscreen, monospace; font-weight: 400; font-size: 1.05rem; color: var(--ink); }
.brand::after { content: "Practice"; font-family: Inter, sans-serif; font-size: .78rem; color: var(--brand); margin-left: .2rem; letter-spacing: 0; }
#nav a { color: var(--muted); font-weight: 500; font-size: .85rem; }
#nav a:hover, #nav a.active { background: transparent; color: var(--ink); }
#nav a.active { color: var(--brand); }
footer { background: rgba(17,17,18,.72); color: var(--muted); font-size: .78rem; border-top: 1px solid var(--line); }

/* botones como los de la web */
.btn { border-radius: 980px; border: 0; background: #2a2a2d; color: var(--ink); font-weight: 500; padding: .6rem 1.2rem; }
.btn:hover { background: #3a3a3d; text-decoration: none; }
.btn.primary { background: var(--btn); color: #fff; } .btn.primary:hover { background: #0077ed; filter: none; }
.btn.small { padding: .35rem .85rem; }
.btn.video { color: #ff6b6b; }

/* tarjetas y paneles: grises sin borde, como las de la web */
.card, .panel, .question, .topics li, .qlist a, .defs > div { background: var(--surface); border: 1px solid transparent; border-radius: var(--radius); }
.card:hover, .qlist a:hover, .option:hover { border-color: var(--brand); }
.card .group, .code, .chip.code, .defs dt, .explanation summary { color: var(--brand); }
.chip { background: #2a2a2d; color: var(--ink); font-weight: 600; }
.chip.d1 { background: rgba(48,209,88,.16); color: #30d158; } .chip.d2 { background: rgba(41,151,255,.16); color: #64b5ff; }
.chip.d3 { background: rgba(255,214,10,.14); color: #ffd60a; } .chip.d4 { background: rgba(255,69,58,.16); color: #ff6b61; }
.note, .empty { background: var(--surface); }
input, select, textarea { background: #1d1d1f; border-color: var(--line); color: var(--ink); border-radius: 12px; }
input:focus, select:focus, textarea:focus { outline: 0; border-color: var(--btn); box-shadow: 0 0 0 4px rgba(0,113,227,.15); }
.option { background: #111112; border-radius: 14px; }
.prose pre { background: #111112; color: #f5f5f7; border: 1px solid var(--line); }
.hero { padding: 3rem 0 1.5rem; } .hero .lead { color: var(--muted); font-size: clamp(1.1rem, 2vw, 1.35rem); line-height: 1.35; }
.hero .mascot { filter: drop-shadow(0 12px 28px rgba(255,111,174,.3)); }
.tabs a.on { color: var(--brand); border-color: var(--brand); }
.lvl.mastered { background: #ff6fae; border-color: #ff6fae; }
@media (max-width: 700px) { .ibx nav a.hide-sm { display: none; } .ibx > div { gap: 12px; } }
footer a, footer a:visited { color: var(--accent); }
/* 2026-10-15 Web-1: caja "Watch the lesson" en páginas de tema con lección en video */
.ibx-lec { display: flex; flex-wrap: wrap; align-items: center; gap: 12px; margin: 14px 0 22px; padding: 14px; border: 1px solid var(--line); border-radius: 14px; background: #1d1d1f; }
.ibx-lec > b { width: 100%; color: var(--brand); font-family: Silkscreen, monospace; font-weight: 400; font-size: .8rem; letter-spacing: .02em; }
.ibx-lec a { display: flex; flex-direction: column; gap: 6px; width: 160px; max-width: calc(50% - 6px); color: #f5f5f7; font-size: .78rem; line-height: 1.3; }
.ibx-lec a:hover { text-decoration: none; color: #fff; } .ibx-lec a:hover img { outline: 2px solid var(--brand); }
.ibx-lec img { width: 100%; height: auto; aspect-ratio: 16/9; object-fit: cover; border-radius: 8px; background: #000; }
/* 2026-10-15 Web-1: el botón "Watch the video lesson" heredaba .video (aspect-ratio 16/9) de AxoPrep y salía como un óvalo enorme */
.btn.video { aspect-ratio: auto; overflow: visible; position: static; background: #2a2a2d; color: #ff6fae; }