/* ==================================================================
   Fibras Ópticas Interactivas — companion del libro
   Paleta Omnivolt · modo oscuro · sin frameworks
   ================================================================== */
:root {
  --azul-deep:   #0a1226;
  --azul-bg:     #0d1830;
  --azul:        #1F3864;
  --azul-medio:  #2E75B6;
  --azul-luz:    #6fb0ff;
  --naranja:     #ED7D31;
  --naranja-luz: #ffb076;
  --verde:       #6fcf8f;
  --rojo:        #ff6b6b;
  --texto:       #eef3fb;
  --texto-suave: rgba(238,243,251,.72);
  --texto-dim:   rgba(238,243,251,.45);
  --linea:       rgba(110,155,220,.18);
  --panel:       rgba(21,35,66,.55);
  --ease-out:    cubic-bezier(.22,.61,.2,1);
  --radius:      18px;
}

* { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; }
body {
  background:
    radial-gradient(1200px 800px at 85% -10%, rgba(46,117,182,.16), transparent 60%),
    radial-gradient(900px 700px at -10% 40%, rgba(237,125,49,.07), transparent 55%),
    linear-gradient(180deg, var(--azul-deep), var(--azul-bg) 40%, #0a1020 100%);
  color: var(--texto);
  font-family: "Inter", system-ui, sans-serif;
  font-size: 17px;
  line-height: 1.65;
  overflow-x: hidden;
}
.mono { font-family: "IBM Plex Mono", ui-monospace, monospace; }
h1, h2 { font-family: "Space Grotesk", "Inter", sans-serif; line-height: 1.06; letter-spacing: -0.02em; }
h1 em, h2 em { font-style: normal; color: var(--naranja); }
a { color: inherit; }
::selection { background: rgba(237,125,49,.35); }

/* ---------- reveals (defensivo) ---------- */
.reveal { opacity: 0; transform: translateY(34px); transition: opacity .8s var(--ease-out), transform .8s var(--ease-out); }
.reveal.is-visible { opacity: 1; transform: none; }
.reveal[data-split] { opacity: 1; transform: none; }

/* ---------- topbar ---------- */
.topbar {
  position: fixed; inset: 0 0 auto 0; z-index: 50;
  display: flex; align-items: center; justify-content: space-between;
  padding: 14px clamp(18px, 4vw, 44px);
  transition: background .35s, box-shadow .35s, padding .35s;
}
.topbar.is-scrolled { background: rgba(10,18,38,.82); backdrop-filter: blur(12px); box-shadow: 0 1px 0 var(--linea); padding-block: 10px; }
.brand { display: flex; align-items: center; gap: 10px; text-decoration: none; font-family: "Space Grotesk"; font-weight: 700; font-size: 1.02rem; }
.brand em { color: var(--naranja); font-style: normal; }
.brand-dot { width: 12px; height: 12px; border-radius: 50%; background: radial-gradient(circle at 35% 35%, var(--naranja-luz), var(--naranja)); box-shadow: 0 0 14px rgba(237,125,49,.8); }
.nav { display: flex; gap: clamp(10px, 2.4vw, 26px); align-items: center; }
.nav a { text-decoration: none; font-size: .92rem; color: var(--texto-suave); padding: 6px 2px; border-bottom: 1px solid transparent; transition: color .25s, border-color .25s; }
.nav a:hover { color: var(--texto); border-color: var(--naranja); }
.nav-cta { border: 1px solid var(--linea); border-radius: 99px; padding: 7px 16px !important; color: var(--texto) !important; }
.nav-cta:hover { background: var(--naranja); border-color: var(--naranja); color: #16233f !important; }

/* ---------- hero ---------- */
.hero { position: relative; min-height: 100svh; display: grid; place-items: center; padding: 120px clamp(18px, 5vw, 60px) 80px; }
.hero-fibra { position: absolute; inset: 0; width: 100%; height: 100%; z-index: 0; }
.hero-inner { position: relative; z-index: 1; max-width: 880px; text-align: center; }
.kicker { font-size: .78rem; letter-spacing: .32em; text-transform: uppercase; color: var(--naranja); }
.hero-title { font-size: clamp(3rem, 8.5vw, 6.4rem); margin: 22px 0 20px; }
.hero-sub { max-width: 640px; margin: 0 auto; color: var(--texto-suave); font-size: 1.06rem; }
.hero-sub strong { color: var(--texto); font-weight: 600; }
.hero-actions { display: flex; gap: 14px; justify-content: center; flex-wrap: wrap; margin-top: 34px; }
.btn { text-decoration: none; font-weight: 600; font-size: .95rem; padding: 14px 26px; border-radius: 99px; transition: transform .25s var(--ease-out), box-shadow .25s, background .25s, color .25s; }
.btn:hover { transform: translateY(-2px); }
.btn-primary { background: linear-gradient(135deg, var(--naranja), #d96a19); color: #171004; box-shadow: 0 8px 26px rgba(237,125,49,.35); }
.btn-primary:hover { box-shadow: 0 12px 34px rgba(237,125,49,.5); }
.btn-ghost { border: 1px solid var(--linea); color: var(--texto); background: rgba(255,255,255,.03); }
.btn-ghost:hover { border-color: var(--azul-medio); background: rgba(46,117,182,.14); }
.hero-stats { list-style: none; display: flex; gap: clamp(18px, 5vw, 54px); justify-content: center; margin-top: 58px; flex-wrap: wrap; }
.hero-stats li { display: grid; gap: 2px; }
.stat { font-size: clamp(1.6rem, 3.4vw, 2.3rem); color: var(--texto); font-weight: 500; }
.stat-label { font-size: .8rem; color: var(--texto-dim); letter-spacing: .06em; }
.hero-scrollhint { position: absolute; bottom: 22px; left: 50%; transform: translateX(-50%); font-size: .72rem; letter-spacing: .3em; color: var(--texto-dim); animation: hint 2.6s ease-in-out infinite; }
@keyframes hint { 0%,100% { transform: translate(-50%,0); opacity:.55 } 50% { transform: translate(-50%,8px); opacity:1 } }

/* ---------- secciones demo ---------- */
.demo { padding: clamp(80px, 12vh, 140px) clamp(18px, 5vw, 60px); max-width: 1180px; margin: 0 auto; }
.demo-alt { position: relative; }
.demo-alt::before { content: ""; position: absolute; inset: 0; background: radial-gradient(800px 400px at 70% 20%, rgba(46,117,182,.10), transparent 65%); pointer-events: none; }
.demo-head { max-width: 760px; margin-bottom: 40px; }
.demo-head h2 { font-size: clamp(2rem, 4.6vw, 3.3rem); margin: 16px 0 18px; }
.demo-lede { color: var(--texto-suave); font-size: 1.04rem; }
.demo-lede strong { color: var(--texto); }
.demo-stage { background: var(--panel); border: 1px solid var(--linea); border-radius: var(--radius); padding: clamp(12px, 2vw, 22px); backdrop-filter: blur(8px); box-shadow: 0 30px 80px rgba(4,8,20,.5); }
.demo-canvas { display: block; width: 100%; height: clamp(320px, 52vh, 460px); border-radius: calc(var(--radius) - 8px); background: #081020; }
.demo-controls { display: flex; flex-wrap: wrap; gap: 16px 26px; align-items: center; padding-top: 16px; }
.ctrl { display: grid; gap: 6px; min-width: 150px; }
.ctrl-wide { min-width: 240px; flex: 1; }
.ctrl-label { font-size: .72rem; letter-spacing: .14em; text-transform: uppercase; color: var(--texto-dim); }
.ctrl-check { grid-template-columns: auto 1fr; align-items: center; gap: 10px; min-width: auto; }
.ctrl-read { margin-left: auto; font-size: .82rem; color: var(--naranja-luz); background: rgba(237,125,49,.08); border: 1px solid rgba(237,125,49,.25); padding: 8px 14px; border-radius: 10px; }
input[type="range"] { appearance: none; -webkit-appearance: none; height: 4px; border-radius: 99px; background: linear-gradient(90deg, var(--azul-medio), var(--naranja)); outline: none; cursor: pointer; }
input[type="range"]::-webkit-slider-thumb { -webkit-appearance: none; width: 18px; height: 18px; border-radius: 50%; background: var(--texto); border: 3px solid var(--naranja); box-shadow: 0 0 12px rgba(237,125,49,.6); cursor: grab; }
input[type="range"]::-moz-range-thumb { width: 18px; height: 18px; border-radius: 50%; background: var(--texto); border: 3px solid var(--naranja); cursor: grab; }
input[type="checkbox"] { width: 18px; height: 18px; accent-color: var(--naranja); cursor: pointer; }
.seg { display: inline-flex; border: 1px solid var(--linea); border-radius: 12px; overflow: hidden; min-width: auto; }
.seg-btn { background: transparent; border: 0; color: var(--texto-suave); font: 600 .88rem "Inter", sans-serif; padding: 10px 18px; cursor: pointer; transition: background .25s, color .25s; }
.seg-btn + .seg-btn { border-left: 1px solid var(--linea); }
.seg-btn:hover { color: var(--texto); background: rgba(46,117,182,.14); }
.seg-btn.is-active { background: var(--azul-medio); color: #08101f; }
.demo-note { max-width: 760px; margin-top: 26px; color: var(--texto-suave); font-size: .96rem; border-left: 3px solid var(--naranja); padding-left: 18px; }
.demo-note .mono { color: var(--naranja-luz); font-size: .88em; }
.ref { display: inline-block; margin-left: 6px; color: var(--texto-dim); font-size: .85em; }

/* ---------- presupuesto PON ---------- */
.budget { margin-top: 18px; display: grid; gap: 12px; }
.budget-bar { position: relative; height: 16px; border-radius: 99px; background: rgba(255,255,255,.06); border: 1px solid var(--linea); overflow: hidden; }
.budget-fill { height: 100%; width: 0%; border-radius: 99px; background: linear-gradient(90deg, var(--azul-medio), var(--naranja)); transition: width .5s var(--ease-out), background .4s; }
.budget-limit { position: absolute; top: -4px; bottom: -4px; width: 2px; background: var(--texto); opacity: .8; }
.budget-rows { display: flex; flex-wrap: wrap; gap: 8px 18px; font-size: .78rem; color: var(--texto-suave); }
.budget-rows b { color: var(--texto); font-weight: 500; }
.budget-verdict { font-weight: 700; font-family: "Space Grotesk"; font-size: 1.05rem; }
.budget-verdict.ok { color: var(--verde); }
.budget-verdict.bad { color: var(--rojo); }

/* ---------- libro ---------- */
.libro { padding: clamp(90px, 14vh, 160px) clamp(18px, 5vw, 60px); }
.libro-grid { max-width: 1080px; margin: 0 auto; display: grid; grid-template-columns: minmax(260px, 380px) 1fr; gap: clamp(30px, 6vw, 80px); align-items: center; }
.libro-info h2 { font-size: clamp(1.9rem, 4vw, 3rem); margin: 14px 0 18px; }
.libro-info p { color: var(--texto-suave); max-width: 560px; }
.libro-caps { list-style: none; counter-reset: cap; display: flex; flex-wrap: wrap; gap: 8px; margin: 26px 0 8px; }
.libro-caps li { counter-increment: cap; font-size: .8rem; color: var(--texto-suave); border: 1px solid var(--linea); border-radius: 99px; padding: 6px 13px; transition: border-color .25s, color .25s, transform .25s; }
.libro-caps li::before { content: counter(cap, decimal-leading-zero) " · "; font-family: "IBM Plex Mono"; color: var(--naranja); font-size: .72rem; }
.libro-caps li:hover { border-color: var(--naranja); color: var(--texto); transform: translateY(-2px); }

/* portada 3D */
.book3d { perspective: 1200px; display: grid; place-items: center; }
.book3d-front {
  position: relative; width: min(300px, 74vw); aspect-ratio: 3 / 4.35;
  background: linear-gradient(155deg, #24457c 0%, var(--azul) 45%, #142545 100%);
  border-radius: 6px 14px 14px 6px; padding: 26px 24px;
  display: flex; flex-direction: column; gap: 8px;
  transform: rotateY(-16deg) rotateX(2deg);
  box-shadow: -30px 40px 80px rgba(3,6,16,.65), inset 2px 0 0 rgba(255,255,255,.09);
  transition: transform .6s var(--ease-out);
}
.book3d:hover .book3d-front { transform: rotateY(-6deg) rotateX(0deg); }
.book3d-kicker { font-size: .62rem; letter-spacing: .3em; text-transform: uppercase; color: var(--naranja-luz); }
.book3d-title { font-family: "Space Grotesk"; font-weight: 700; font-size: clamp(2rem, 5vw, 2.7rem); line-height: 1.02; margin-top: 8px; }
.book3d-sub { font-size: .85rem; color: rgba(238,243,251,.75); margin-top: 4px; }
.book3d-author { margin-top: auto; font-size: .8rem; color: var(--naranja-luz); font-weight: 600; }
.book3d-beam { position: absolute; left: -8%; right: -8%; top: 58%; height: 3px; border-radius: 99px;
  background: linear-gradient(90deg, transparent, var(--naranja) 30%, #ffd9b8 50%, var(--naranja) 70%, transparent);
  box-shadow: 0 0 18px rgba(237,125,49,.9); animation: beam 3.4s ease-in-out infinite; }
@keyframes beam { 0%,100% { opacity:.45; transform: scaleX(.92) } 50% { opacity:1; transform: scaleX(1) } }
.book3d-spine { display: none; }

/* ---------- footer ---------- */
.footer { border-top: 1px solid var(--linea); padding: 40px clamp(18px, 5vw, 60px) 48px; text-align: center; display: grid; gap: 8px; }
.footer-fine { font-size: .72rem; color: var(--texto-dim); letter-spacing: .05em; }

/* ---------- responsive ---------- */
@media (max-width: 860px) {
  .libro-grid { grid-template-columns: 1fr; }
  .libro-cover { order: -1; }
  .nav a:not(.nav-cta) { display: none; }
  .ctrl-read { margin-left: 0; }
  .demo-canvas { height: clamp(300px, 46vh, 400px); }
}

/* ---------- reduced motion: solo lo intrusivo ---------- */
@media (prefers-reduced-motion: reduce) {
  .hero-scrollhint { animation: none; }
  .book3d-beam { animation: none; opacity: .8; }
  /* Las demos y micro-interacciones permanecen: son el contenido. */
}

/* anclas con header fijo */
section[id], footer { scroll-margin-top: 84px; }

/* ---------- iteración 2: botón de juego OTDR ---------- */
.btn-mini {
  background: rgba(46,117,182,.14); border: 1px solid var(--linea); color: var(--texto);
  font: 600 .85rem "Inter", sans-serif; padding: 10px 18px; border-radius: 10px; cursor: pointer;
  transition: background .25s, border-color .25s, color .25s;
}
.btn-mini:hover { border-color: var(--naranja); }
.btn-mini.is-on { background: var(--naranja); border-color: var(--naranja); color: #171004; }
.ctrl-score { color: var(--verde); border-color: rgba(111,207,143,.35); background: rgba(111,207,143,.08); }

/* ---------- iteración 3: herramientas ---------- */
.tools-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(270px, 1fr)); gap: 18px; }
.tool { background: var(--panel); border: 1px solid var(--linea); border-radius: var(--radius); padding: 22px; backdrop-filter: blur(8px); }
.tool h3 { font-size: .85rem; letter-spacing: .18em; text-transform: uppercase; color: var(--naranja); margin-bottom: 16px; font-weight: 500; }
.tool-row { display: grid; grid-template-columns: 1fr 96px; align-items: center; gap: 10px; margin-bottom: 10px; font-size: .86rem; color: var(--texto-suave); }
.tool-row input { background: rgba(8,16,32,.8); border: 1px solid var(--linea); border-radius: 8px; color: var(--texto); font: 500 .9rem "IBM Plex Mono", monospace; padding: 8px 10px; width: 100%; }
.tool-row input:focus { outline: none; border-color: var(--naranja); }
.tool-out { margin-top: 14px; padding: 12px 14px; border-radius: 10px; background: rgba(46,117,182,.10); border: 1px solid var(--linea); font-size: .84rem; line-height: 1.5; color: var(--texto); }
.tool-out.ok { border-color: rgba(111,207,143,.4); }
.tool-out.bad { border-color: rgba(255,107,107,.45); }

/* ---------- quiz ---------- */
.quiz-card { background: var(--panel); border: 1px solid var(--linea); border-radius: var(--radius); padding: clamp(24px, 4vw, 40px); backdrop-filter: blur(8px); max-width: 760px; }
.qz-idle { text-align: center; padding: 20px 0; }
.qz-progress { font-size: .74rem; letter-spacing: .2em; color: var(--texto-dim); text-transform: uppercase; }
.qz-q { font-family: "Space Grotesk"; font-size: clamp(1.15rem, 2.4vw, 1.5rem); font-weight: 500; margin: 14px 0 20px; line-height: 1.35; }
.qz-opts { display: grid; gap: 10px; }
.qz-opt { text-align: left; background: rgba(8,16,32,.6); border: 1px solid var(--linea); border-radius: 12px; color: var(--texto); font: 500 .95rem "Inter", sans-serif; padding: 14px 18px; cursor: pointer; transition: border-color .2s, background .2s, transform .2s; }
.qz-opt:hover:not(:disabled) { border-color: var(--azul-medio); transform: translateX(4px); }
.qz-opt:disabled { cursor: default; opacity: .75; }
.qz-opt.correct { border-color: var(--verde); background: rgba(111,207,143,.12); opacity: 1; }
.qz-opt.wrong { border-color: var(--rojo); background: rgba(255,107,107,.10); }
.qz-exp { margin-top: 16px; font-size: .92rem; color: var(--texto-suave); border-left: 3px solid var(--naranja); padding-left: 14px; }
.qz-exp b { color: var(--texto); }
#qz-next { margin-top: 18px; }

/* ==================================================================
   Iteración 4 · Demo DNANF (fibra de núcleo hueco antiresonante)
   ================================================================== */
.dnanf-controls { display: flex; flex-wrap: wrap; gap: 12px; align-items: center; margin-bottom: 14px; }
.dnanf-badge {
  margin-left: auto; font-size: .78rem; color: var(--naranja-luz);
  border: 1px dashed rgba(237,125,49,.4); border-radius: 8px; padding: 9px 14px;
  background: rgba(237,125,49,.06); transition: color .3s, border-color .3s, background .3s;
}
.dnanf-badge.leak { color: var(--rojo); border-color: rgba(255,107,107,.5); background: rgba(255,107,107,.07); }
.dnanf-fig {
  background: linear-gradient(180deg, #0a1428, #081020);
  border: 1px solid var(--linea); border-radius: 14px; padding: 10px 8px 2px; overflow: hidden;
}
.dnanf-fig svg { width: 100%; height: auto; display: block; }
.dnanf-fig text { font-family: "Inter", sans-serif; }
#dnanf .dn-lbl { fill: var(--texto-suave); font-size: 13px; font-weight: 500; }
#dnanf .dn-lbl-strong { fill: var(--texto); font-size: 13.5px; font-weight: 600; }
#dnanf .dn-mono { font-family: "IBM Plex Mono", monospace; fill: var(--naranja-luz); font-size: 12.5px; }
#dnanf .dn-mono-dim { font-family: "IBM Plex Mono", monospace; fill: var(--texto-dim); font-size: 11px; }
#dnanf .dn-tiny { fill: var(--texto-dim); font-size: 10.5px; }

.dn-dashflow { stroke-dasharray: 7 26; animation: dn-flow 1.5s linear infinite; }
@keyframes dn-flow { to { stroke-dashoffset: -330; } }
.dn-pulse { offset-path: path('M 218 406 L 438 214 L 658 406 L 878 214 L 1098 406');
  animation: dn-travel 5.2s linear infinite; }
@keyframes dn-travel { from { offset-distance: 0%; } to { offset-distance: 100%; } }

.dn-beam-decay, .dn-leak-big { opacity: 0; transition: opacity .5s; }
.dnanf-fig.resonant .dn-beam-decay,
.dnanf-fig.resonant .dn-leak-big { opacity: 1; }
.dnanf-fig.resonant .dn-beam-main,
.dnanf-fig.resonant .dn-dashflow,
.dnanf-fig.resonant .dn-pulse { opacity: .12; }
.dnanf-fig.resonant .dn-membrane { opacity: .32; }
.dn-membrane { transition: opacity .5s; }

.dnanf-cap { color: var(--texto-dim); font-size: 12px; line-height: 1.55; padding: 12px 10px 14px; }
.dnanf-cards { display: grid; grid-template-columns: repeat(auto-fit, minmax(280px, 1fr)); gap: 14px; margin-top: 16px; }
.dnanf-card { background: rgba(21,35,66,.4); border: 1px solid var(--linea); border-radius: 14px; padding: 20px; }
.dnanf-card h3 { font-family: "Space Grotesk", sans-serif; font-weight: 600; font-size: 1.05rem; margin-bottom: 10px; color: var(--texto); }
.dnanf-card p { color: var(--texto-suave); font-size: .86rem; line-height: 1.6; }
.dnanf-card b { color: var(--texto); font-weight: 600; }
.dnanf-formula { color: var(--texto); font-size: .8rem; background: rgba(8,16,32,.7);
  border: 1px solid var(--linea); border-radius: 8px; padding: 10px 12px; margin: 10px 0; line-height: 1.8; }
.dnanf-stat { display: flex; justify-content: space-between; font-size: .78rem;
  padding: 7px 0; border-bottom: 1px dotted rgba(110,155,220,.18); color: var(--texto); }
.dnanf-stat span:last-child { color: var(--naranja-luz); }
.dnanf-stat:last-of-type { border-bottom: 0; }

@media (prefers-reduced-motion: reduce) {
  .dn-dashflow, .dn-pulse { animation: none; }
}

/* ==================================================================
   Iteración 5 · Calculadora de capacidad de carrete
   ================================================================== */
.carrete-toggle { display: flex; justify-content: center; margin-bottom: 20px; }
.carrete-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 20px; align-items: start; }
.carrete-inputs, .carrete-result { background: rgba(21,35,66,.4); border: 1px solid var(--linea); border-radius: 14px; padding: 20px; }
.carrete-sub { font-size: .72rem; letter-spacing: .16em; text-transform: uppercase; color: var(--naranja); margin-bottom: 14px; }
.carrete-result { display: flex; flex-direction: column; }
.carrete-big { font-size: clamp(2.4rem, 6vw, 3.4rem); font-weight: 500; color: var(--texto); line-height: 1; }
.carrete-big span:first-child { color: var(--naranja-luz); }
.carrete-unit { font-size: 1.1rem; color: var(--texto-dim); }
.carrete-big-sub { font-size: .9rem; color: var(--texto-suave); margin-top: 6px; }
.carrete-stats { margin-top: 18px; }
.carrete-stats .dnanf-stat { font-size: .8rem; }
.carrete-table-wrap { overflow-x: auto; border: 1px solid var(--linea); border-radius: 12px; }
.carrete-table { width: 100%; border-collapse: collapse; font-size: .8rem; min-width: 520px; }
.carrete-table th { text-align: right; color: var(--texto-dim); font-weight: 500; padding: 10px 12px; border-bottom: 1px solid var(--linea); letter-spacing: .04em; }
.carrete-table th:first-child { text-align: left; }
.carrete-table td { text-align: right; padding: 10px 12px; border-bottom: 1px solid rgba(110,155,220,.10); color: var(--texto-suave); }
.carrete-table td:first-child { text-align: left; color: var(--texto); }
.carrete-table tbody tr:last-child td { border-bottom: 0; }
.carrete-table tr.fits td { background: rgba(111,207,143,.06); }
.carrete-table .yes { color: var(--verde); font-weight: 500; }
.carrete-table .no { color: var(--texto-dim); }
.carrete-table .best td { background: rgba(237,125,49,.10); }
.carrete-table .best td:first-child::after { content: " ◂ mínimo"; color: var(--naranja); font-size: .7rem; }
.carrete-hint { font-size: .72rem; color: var(--texto-dim); margin-top: 10px; }
@media (max-width: 720px) { .carrete-grid { grid-template-columns: 1fr; } }

/* figura reactiva del carrete */
.carrete-viz { display: block; width: 100%; height: clamp(300px, 40vh, 380px);
  border-radius: 14px; background: linear-gradient(180deg,#0a1428,#081020);
  border: 1px solid var(--linea); margin-bottom: 20px; }

/* ==================================================================
   Iteración 6 · Sección «El libro» ampliada: compra, muestra, docentes
   ================================================================== */
.libro-bloque { max-width: 1080px; margin: clamp(70px, 10vh, 110px) auto 0; }
.libro-bloque .demo-head { margin-bottom: 30px; }
.libro-bloque .demo-head h2 { font-size: clamp(1.7rem, 3.6vw, 2.6rem); }

/* --- tarjetas de compra --- */
.shop-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(270px, 1fr)); gap: 18px; }
.shop-card {
  display: flex; flex-direction: column; gap: 10px;
  background: var(--panel); border: 1px solid var(--linea); border-radius: var(--radius);
  padding: clamp(22px, 3vw, 30px); backdrop-filter: blur(8px);
  transition: transform .3s var(--ease-out), border-color .3s, box-shadow .3s;
}
.shop-card:hover { transform: translateY(-4px); border-color: rgba(237,125,49,.45); box-shadow: 0 24px 60px rgba(4,8,20,.45); }
.shop-card-free { border-style: dashed; }
.shop-kicker { font-size: .7rem; letter-spacing: .26em; text-transform: uppercase; color: var(--naranja); }
.shop-card h3 { font-family: "Space Grotesk", sans-serif; font-size: 1.25rem; font-weight: 600; line-height: 1.2; }
.shop-desc { color: var(--texto-suave); font-size: .9rem; flex: 1; }
.shop-price { font-size: .8rem; color: var(--naranja-luz); }
.shop-btn { text-align: center; margin-top: 4px; }
.shop-btn.is-soon { background: rgba(46,117,182,.16); color: var(--texto); box-shadow: none; border: 1px dashed rgba(110,155,220,.45); }
.shop-btn.is-soon:hover { border-color: var(--naranja); box-shadow: none; }
.shop-alt { font-size: .82rem; color: var(--texto-suave); text-align: center; text-decoration: none; border-bottom: 1px dotted var(--texto-dim); align-self: center; }
.shop-alt:hover { color: var(--naranja-luz); border-color: var(--naranja); }

/* --- lista de lanzamiento --- */
.aviso-card {
  display: grid; grid-template-columns: 1.2fr 1fr; gap: clamp(20px, 4vw, 48px); align-items: center;
  background: linear-gradient(135deg, rgba(46,117,182,.16), rgba(237,125,49,.10));
  border: 1px solid var(--linea); border-radius: var(--radius); padding: clamp(24px, 4vw, 40px);
}
.aviso-txt h3 { font-family: "Space Grotesk", sans-serif; font-size: clamp(1.3rem, 2.6vw, 1.7rem); margin: 10px 0 10px; }
.aviso-txt h3 em { font-style: normal; color: var(--naranja); }
.aviso-form { display: grid; gap: 10px; }
.aviso-form input[type="email"] {
  background: rgba(8,16,32,.8); border: 1px solid var(--linea); border-radius: 12px;
  color: var(--texto); font: 500 1rem "Inter", sans-serif; padding: 14px 16px; width: 100%;
}
.aviso-form input[type="email"]:focus { outline: none; border-color: var(--naranja); }
.aviso-form .btn { border: 0; cursor: pointer; font-family: "Inter", sans-serif; }

/* --- formulario de profesores --- */
.prof-form { background: var(--panel); border: 1px solid var(--linea); border-radius: var(--radius); padding: clamp(22px, 3.5vw, 36px); backdrop-filter: blur(8px); }
.prof-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 14px 18px; }
.form-row { display: grid; gap: 6px; font-size: .82rem; color: var(--texto-suave); }
.form-row span { letter-spacing: .08em; text-transform: uppercase; font-size: .7rem; color: var(--texto-dim); }
.form-row input, .form-row textarea {
  background: rgba(8,16,32,.8); border: 1px solid var(--linea); border-radius: 10px;
  color: var(--texto); font: 500 .95rem "Inter", sans-serif; padding: 12px 14px; width: 100%; resize: vertical;
}
.form-row input:focus, .form-row textarea:focus { outline: none; border-color: var(--naranja); }
.form-row-full { grid-column: 1 / -1; }
.prof-actions { display: flex; flex-wrap: wrap; align-items: center; gap: 16px; margin-top: 20px; }
.prof-actions .btn { border: 0; cursor: pointer; font-family: "Inter", sans-serif; }
.form-status { font-size: .8rem; min-height: 1.2em; }
.form-status.ok { color: var(--verde); }
.form-status.bad { color: var(--rojo); }
.form-fine { margin-top: 14px; font-size: .7rem; color: var(--texto-dim); }

/* honeypot + utilidades */
.hp { position: absolute !important; left: -9999px !important; width: 1px; height: 1px; opacity: 0; }
.visually-hidden { position: absolute; width: 1px; height: 1px; overflow: hidden; clip: rect(0 0 0 0); white-space: nowrap; }

@media (max-width: 760px) {
  .aviso-card { grid-template-columns: 1fr; }
  .prof-grid { grid-template-columns: 1fr; }
}

/* ---------- iteración v8.5: demos de conectorización (cap. 16) ---------- */
.linea-leyenda {
  display: none; margin-top: 12px; font-size: .74rem; line-height: 1.6;
  color: var(--texto-dim); text-align: center;
}
@media (max-width: 620px) {
  .linea-leyenda { display: block; }
}