/* ISTC View · view.istcglobal.mx — sigue el DESIGN.md de istcglobal.mx (ingeniería sobria) */
:root {
  --paper: #F5F4F0; --surface: #FFFFFF; --ink: #0E1A2B; --ink-2: #4A5566; --ink-3: #6B7585;
  --line: #DCDAD3; --brand: #0B4EA2; --brand-ink: #083B7A; --accent: #6DB33F; --night: #0A1626;
  --rec: #E5484D; --on-night: #E9EEF5; --on-night-2: #A3AFC0; --night-line: #22324A;
  --shadow: 0 1px 0 rgba(14,26,43,.04), 0 12px 32px -16px rgba(14,26,43,.25);
  --sans: "Archivo", system-ui, "Segoe UI", sans-serif;
  --mono: "IBM Plex Mono", ui-monospace, Consolas, monospace;
  color-scheme: light;
}
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --paper: #0B111B; --surface: #111A27; --ink: #E9EEF5; --ink-2: #A3AFC0; --ink-3: #7D899B;
    --line: #223044; --brand: #5B9BFF; --brand-ink: #8DB9FF; --accent: #8DD05A; --night: #060B13;
    --night-line: #1A2638; --shadow: 0 1px 0 rgba(0,0,0,.3), 0 12px 32px -16px rgba(0,0,0,.6);
    color-scheme: dark;
  }
}
:root[data-theme="dark"] {
  --paper: #0B111B; --surface: #111A27; --ink: #E9EEF5; --ink-2: #A3AFC0; --ink-3: #7D899B;
  --line: #223044; --brand: #5B9BFF; --brand-ink: #8DB9FF; --accent: #8DD05A; --night: #060B13;
  --night-line: #1A2638; color-scheme: dark;
}

*, *::before, *::after { box-sizing: border-box; }
html { scroll-behavior: smooth; -webkit-text-size-adjust: 100%; }
@media (prefers-reduced-motion: reduce) { html { scroll-behavior: auto; } *, *::before, *::after { animation: none !important; transition: none !important; } }
body { margin: 0; background: var(--paper); color: var(--ink); font: 400 16px/1.6 var(--sans); overflow-x: hidden; }
img { max-width: 100%; display: block; }
a { color: var(--brand); }
a:hover { color: var(--brand-ink); }
:focus-visible { outline: 2px solid var(--accent); outline-offset: 3px; border-radius: 4px; }
.skip { position: absolute; left: -9999px; top: 8px; background: var(--brand); color: #fff; padding: 8px 14px; border-radius: 8px; z-index: 100; }
.skip:focus { left: 16px; }

.wrap { width: 100%; max-width: 1200px; margin: 0 auto; padding: 0 24px; }
@media (max-width: 640px) { .wrap { padding: 0 16px; } }

h1, h2, h3 { font-stretch: 112%; letter-spacing: -0.01em; margin: 0; }
h1 { font-size: clamp(40px, 6vw, 64px); line-height: 1.02; font-weight: 800; }
h2 { font-size: clamp(30px, 4vw, 40px); line-height: 1.08; font-weight: 800; }
h3 { font-size: 22px; line-height: 1.3; font-weight: 600; }
p { margin: 0; }
.lead { font-size: 18px; line-height: 1.55; color: var(--ink-2); max-width: 60ch; }
.tag { font: 500 13px/1.4 var(--mono); letter-spacing: .04em; text-transform: uppercase; color: var(--ink-3); }
.mono { font-family: var(--mono); }

/* Botones */
.btn { display: inline-flex; align-items: center; justify-content: center; gap: 10px; min-height: 48px; padding: 0 22px;
  border-radius: 8px; font: 600 16px/1 var(--sans); text-decoration: none; border: 1px solid transparent; cursor: pointer; transition: background .15s, border-color .15s; }
.btn-primary { background: var(--brand); color: #fff; }
.btn-primary:hover { background: var(--brand-ink); color: #fff; }
:root[data-theme="dark"] .btn-primary, :root[data-theme="dark"] .btn-primary:hover { color: #06101F; }
@media (prefers-color-scheme: dark) { :root:not([data-theme="light"]) .btn-primary, :root:not([data-theme="light"]) .btn-primary:hover { color: #06101F; } }
.btn-ghost { border-color: var(--line); color: var(--ink); background: transparent; }
.btn-ghost:hover { border-color: var(--ink); color: var(--ink); }
.btn svg { width: 18px; height: 18px; flex: none; }
.link-arrow { font-weight: 600; text-decoration: none; }
.link-arrow:hover { text-decoration: underline; }

/* Navegación */
.nav { position: sticky; top: 0; z-index: 50; background: color-mix(in srgb, var(--paper) 88%, transparent); backdrop-filter: blur(10px); border-bottom: 1px solid transparent; transition: border-color .2s; }
.nav.scrolled { border-bottom-color: var(--line); }
.nav .wrap { display: flex; align-items: center; justify-content: space-between; height: 68px; gap: 16px; }
.brand { display: flex; align-items: center; gap: 10px; text-decoration: none; color: var(--ink); font-weight: 800; font-stretch: 112%; font-size: 18px; }
.brand img { width: 30px; height: 30px; }
.brand small { font: 500 12px var(--mono); color: var(--ink-3); font-stretch: 100%; }
.nav-links { display: flex; align-items: center; gap: 28px; }
.nav-links a { color: var(--ink-2); text-decoration: none; font-weight: 500; }
.nav-links a:hover { color: var(--ink); }
.nav-links .btn { min-height: 40px; padding: 0 16px; color: #fff; }
.menu-btn { display: none; background: none; border: 1px solid var(--line); border-radius: 8px; width: 44px; height: 44px; color: var(--ink); cursor: pointer; }
@media (max-width: 900px) {
  .menu-btn { display: inline-flex; align-items: center; justify-content: center; }
  .nav-links { display: none; position: absolute; top: 68px; left: 0; right: 0; flex-direction: column; align-items: stretch; gap: 0;
    background: var(--paper); border-bottom: 1px solid var(--line); padding: 8px 16px 16px; }
  .nav-links.open { display: flex; }
  .nav-links a { padding: 12px 0; border-top: 1px solid var(--line); }
  .nav-links .btn { margin-top: 12px; min-height: 48px; border-top: 0; }
}

/* Portada */
.hero { background: var(--night); color: var(--on-night); position: relative; overflow: hidden; }
.hero::before { content: ""; position: absolute; inset: 0 0 auto 0; height: 1px; background: linear-gradient(90deg, var(--accent), var(--brand)); }
.hero::after { content: ""; position: absolute; inset: 0; pointer-events: none;
  background: radial-gradient(600px 400px at 85% 20%, rgba(91,155,255,.18), transparent 70%), radial-gradient(500px 360px at 10% 90%, rgba(109,179,63,.10), transparent 70%); }
.hero .wrap { position: relative; z-index: 1; display: grid; grid-template-columns: 1.05fr 1fr; gap: 56px; align-items: center; padding-top: 96px; padding-bottom: 104px; }
.hero .tag { color: #8DD05A; }
.hero h1 { margin: 16px 0 20px; color: #fff; }
.hero .lead { color: var(--on-night-2); }
.hero-ctas { display: flex; flex-wrap: wrap; gap: 12px; margin-top: 32px; }
.hero .btn-primary { background: #5B9BFF; color: #06101F; }
.hero .btn-primary:hover { background: #8DB9FF; color: #06101F; }
.hero .btn-ghost { border-color: var(--night-line); color: var(--on-night); }
.hero .btn-ghost:hover { border-color: var(--on-night); }
.hero-meta { margin-top: 16px; font: 400 13px/1.5 var(--mono); color: var(--on-night-2); }
@media (max-width: 960px) { .hero .wrap { grid-template-columns: 1fr; gap: 48px; padding-top: 64px; padding-bottom: 72px; } }

/* Ilustración: mosaico de NVR hecho con CSS */
.nvr { background: #04070D; border: 1px solid var(--night-line); border-radius: 14px; padding: 10px; box-shadow: 0 30px 80px -30px rgba(0,0,0,.8); }
.nvr-bar { display: flex; justify-content: space-between; align-items: center; padding: 2px 4px 10px; font: 500 11px var(--mono); color: #7D899B; }
.nvr-bar b { color: #E9EEF5; font-weight: 500; }
.nvr-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 4px; }
.cam { position: relative; aspect-ratio: 16/9; border-radius: 3px; overflow: hidden; background: #111B29; }
.cam::before { content: ""; position: absolute; inset: 0; }
.cam .lbl { position: absolute; left: 5px; bottom: 4px; font: 500 9px var(--mono); color: rgba(255,255,255,.75); text-shadow: 0 1px 2px #000; }
.cam.c1::before { background: linear-gradient(180deg, #2A3B4F 0 45%, #3B4A3A 45% 100%); }
.cam.c2::before { background: linear-gradient(160deg, #3A3530, #1D2430 60%), radial-gradient(circle at 70% 30%, #5A5244 0 12%, transparent 13%); }
.cam.c3::before { background: repeating-linear-gradient(90deg, #22303F 0 18%, #1A2532 18% 22%), linear-gradient(#22303F, #22303F); }
.cam.c4::before { background: linear-gradient(200deg, #2C3542, #161E28 70%); }
.cam.c6::before { background: linear-gradient(180deg, #34404D 0 35%, #262E36 35%); }
.cam.c7::before { background: radial-gradient(ellipse at 50% 120%, #3E4A3A, #18202A 70%); }
.cam.c8::before { background: linear-gradient(120deg, #1E2734, #2F3A47); }
.cam.c9::before { background: linear-gradient(180deg, #23303D 0 55%, #3A3F45 55%); }
/* El cuadro que es una pantalla de PC */
.cam.pc { outline: 2px solid #8DD05A; outline-offset: -2px; background: #0E3E80; }
.pc .desk { position: absolute; inset: 0 0 12% 0; background: linear-gradient(135deg, #0B4EA2, #0A2E5C); }
.pc .win { position: absolute; background: #F5F4F0; border-radius: 2px; box-shadow: 0 2px 6px rgba(0,0,0,.4); }
.pc .win::before { content: ""; position: absolute; left: 0; right: 0; top: 0; height: 12%; background: #DCDAD3; }
.pc .w1 { left: 8%; top: 12%; width: 52%; height: 58%; }
.pc .w1::after { content: ""; position: absolute; left: 8%; right: 8%; top: 24%; height: 60%;
  background: repeating-linear-gradient(180deg, #C9CED6 0 6%, transparent 6% 14%); }
.pc .w2 { left: 54%; top: 30%; width: 38%; height: 46%; background: #FFFFFF; }
.pc .w2::after { content: ""; position: absolute; left: 10%; bottom: 14%; width: 80%; height: 46%;
  background: linear-gradient(90deg, #6DB33F 0 30%, transparent 30% 36%, #0B4EA2 36% 70%, transparent 70% 76%, #E3A13B 76%); clip-path: polygon(0 100%, 0 40%, 30% 40%, 30% 100%, 36% 100%, 36% 0, 70% 0, 70% 100%, 76% 100%, 76% 60%, 100% 60%, 100% 100%); }
.pc .task { position: absolute; left: 0; right: 0; bottom: 0; height: 12%; background: #1B2330; }
.pc .osd { position: absolute; left: 5px; top: 4px; font: 500 8px var(--mono); color: #fff; background: rgba(0,0,0,.55); padding: 1px 4px; border-radius: 2px; }
.pc .rec { position: absolute; right: 5px; top: 5px; display: flex; align-items: center; gap: 3px; font: 600 8px var(--mono); color: #fff; }
.pc .rec::before { content: ""; width: 6px; height: 6px; border-radius: 50%; background: var(--rec); animation: blink 1.4s infinite; }
@keyframes blink { 50% { opacity: .25; } }
.nvr-cap { margin-top: 12px; font: 400 12px/1.5 var(--mono); color: #7D899B; text-align: center; }

/* Secciones */
section { padding: 120px 0; }
@media (max-width: 640px) { section { padding: 72px 0; } }
.sec-head { max-width: 760px; margin-bottom: 56px; }
.sec-head h2 { margin: 12px 0 16px; }
.alt { background: var(--surface); border-top: 1px solid var(--line); border-bottom: 1px solid var(--line); }

/* Usos */
.uses { display: grid; grid-template-columns: repeat(4, 1fr); border-top: 1px solid var(--line); }
.use { padding: 28px 24px 8px 0; }
.use + .use { padding-left: 24px; border-left: 1px solid var(--line); }
.use svg { width: 28px; height: 28px; color: var(--brand); margin-bottom: 16px; }
.use h3 { font-size: 19px; margin-bottom: 8px; }
.use p { color: var(--ink-2); font-size: 15px; }
@media (max-width: 960px) { .uses { grid-template-columns: 1fr 1fr; } .use:nth-child(3) { border-left: 0; padding-left: 0; } .use:nth-child(n+3) { border-top: 1px solid var(--line); } }
@media (max-width: 560px) { .uses { grid-template-columns: 1fr; } .use, .use + .use { border-left: 0; padding-left: 0; } .use + .use { border-top: 1px solid var(--line); } }

/* Pasos */
.steps { counter-reset: s; display: grid; gap: 0; }
.step { display: grid; grid-template-columns: 96px 1fr 1.2fr; gap: 24px; padding: 32px 0; border-top: 1px solid var(--line); align-items: start; }
.step:last-child { border-bottom: 1px solid var(--line); }
.step .n { font: 500 15px var(--mono); color: var(--brand); padding-top: 4px; }
.step p { color: var(--ink-2); }
.step code { font-family: var(--mono); font-size: 14px; background: var(--paper); border: 1px solid var(--line); padding: 1px 6px; border-radius: 4px; color: var(--ink); }
@media (max-width: 760px) { .step { grid-template-columns: 1fr; gap: 8px; } }

/* Ficha técnica */
.spec { display: grid; grid-template-columns: 1fr 1fr; gap: 0 48px; }
.spec dl { margin: 0; }
.row { display: grid; grid-template-columns: 180px 1fr; gap: 16px; padding: 16px 0; border-top: 1px solid var(--line); }
.row dt { font: 500 13px/1.5 var(--mono); color: var(--ink-3); text-transform: uppercase; letter-spacing: .03em; padding-top: 2px; }
.row dd { margin: 0; }
.row dd small { display: block; color: var(--ink-2); font-size: 14px; }
.tested { margin-top: 32px; display: flex; gap: 12px; align-items: flex-start; padding: 16px 18px; border: 1px solid var(--line); border-radius: 14px; background: var(--paper); color: var(--ink-2); font-size: 15px; }
.tested .dot { width: 8px; height: 8px; border-radius: 50%; background: var(--accent); margin-top: 8px; flex: none; }
@media (max-width: 860px) { .spec { grid-template-columns: 1fr; } .row { grid-template-columns: 130px 1fr; } }

/* Precios */
.plans { display: grid; grid-template-columns: repeat(3, 1fr); gap: 20px; align-items: stretch; }
.plan { background: var(--surface); border: 1px solid var(--line); border-radius: 14px; padding: 32px 28px; display: flex; flex-direction: column; gap: 18px; }
.plan.featured { border: 2px solid var(--brand); box-shadow: var(--shadow); position: relative; }
.plan .badge { position: absolute; top: -12px; left: 24px; background: var(--brand); color: #fff; font: 500 12px var(--mono); padding: 4px 10px; border-radius: 4px; }
:root[data-theme="dark"] .plan .badge { color: #06101F; }
@media (prefers-color-scheme: dark) { :root:not([data-theme="light"]) .plan .badge { color: #06101F; } }
.plan h3 { font-size: 20px; }
.price { display: flex; align-items: baseline; gap: 8px; flex-wrap: wrap; }
.price b { font-size: 48px; line-height: 1; font-weight: 800; font-stretch: 112%; letter-spacing: -0.02em; }
.price span { color: var(--ink-3); font: 400 14px var(--mono); }
.plan .note { color: var(--ink-2); font-size: 15px; min-height: 48px; }
.plan ul { list-style: none; margin: 0; padding: 0; display: grid; gap: 10px; font-size: 15px; }
.plan li { display: flex; gap: 10px; }
.plan li svg { width: 18px; height: 18px; color: var(--accent); flex: none; margin-top: 3px; }
.plan .btn { margin-top: auto; }
.price-foot { margin-top: 24px; color: var(--ink-3); font: 400 13px/1.6 var(--mono); }
@media (max-width: 900px) { .plans { grid-template-columns: 1fr; max-width: 480px; } .plan .note { min-height: 0; } }

/* Descarga */
.download { background: var(--night); color: var(--on-night); }
.download .wrap { display: grid; grid-template-columns: 1.1fr 1fr; gap: 48px; align-items: center; }
.download h2 { color: #fff; margin: 12px 0 16px; }
.download .lead { color: var(--on-night-2); }
.download .tag { color: #8DD05A; }
.dl-card { background: #0E1B2E; border: 1px solid var(--night-line); border-radius: 14px; padding: 24px; }
.dl-card .btn-primary { width: 100%; background: #5B9BFF; color: #06101F; }
.dl-card .btn-primary:hover { background: #8DB9FF; }
.dl-card dl { margin: 20px 0 0; font: 400 13px/1.6 var(--mono); color: var(--on-night-2); }
.dl-card dl div { display: grid; grid-template-columns: 110px 1fr; gap: 12px; padding: 8px 0; border-top: 1px solid var(--night-line); }
.dl-card dt { color: #7D899B; }
.dl-card dd { margin: 0; color: var(--on-night); word-break: break-all; }
.req { margin-top: 28px; display: grid; gap: 10px; padding: 0; list-style: none; color: var(--on-night-2); }
.req li { display: flex; gap: 10px; }
.req li::before { content: ""; width: 6px; height: 6px; border-radius: 50%; background: #8DD05A; margin-top: 10px; flex: none; }
@media (max-width: 900px) { .download .wrap { grid-template-columns: 1fr; } }

/* Preguntas */
.faq { border-top: 1px solid var(--line); }
.faq details { border-bottom: 1px solid var(--line); }
.faq summary { list-style: none; cursor: pointer; padding: 22px 44px 22px 0; position: relative; font-weight: 600; font-size: 18px; }
.faq summary::-webkit-details-marker { display: none; }
.faq summary::after { content: "+"; position: absolute; right: 4px; top: 18px; font: 400 26px/1 var(--mono); color: var(--brand); transition: transform .2s; }
.faq details[open] summary::after { transform: rotate(45deg); }
.faq .ans { padding: 0 0 24px; color: var(--ink-2); max-width: 72ch; display: grid; gap: 12px; }
.faq .ans ol, .faq .ans ul { margin: 0; padding-left: 22px; display: grid; gap: 6px; }
.faq .ans code { font-family: var(--mono); font-size: 14px; background: var(--surface); border: 1px solid var(--line); padding: 1px 6px; border-radius: 4px; color: var(--ink); }
.faq-group { margin-top: 56px; }
.faq-group:first-of-type { margin-top: 0; }
.faq-group > .tag { display: block; margin-bottom: 12px; }
.more { margin-top: 32px; }

/* CTA final + pie */
.cta-final { text-align: left; }
.cta-final .wrap { display: flex; justify-content: space-between; align-items: center; gap: 32px; flex-wrap: wrap; }
.cta-final h2 { max-width: 18ch; }
.cta-final .ctas { display: flex; gap: 12px; flex-wrap: wrap; }
footer { background: var(--night); color: var(--on-night-2); padding: 64px 0 40px; font-size: 15px; }
footer .wrap { display: grid; grid-template-columns: 1.4fr 1fr 1fr; gap: 40px; }
footer a { color: var(--on-night); text-decoration: none; }
footer a:hover { color: #fff; text-decoration: underline; }
footer h4 { margin: 0 0 14px; font: 500 12px var(--mono); text-transform: uppercase; letter-spacing: .05em; color: #7D899B; }
footer ul { list-style: none; margin: 0; padding: 0; display: grid; gap: 8px; }
.foot-brand { display: flex; gap: 12px; align-items: center; color: #fff; font-weight: 800; font-stretch: 112%; font-size: 18px; margin-bottom: 12px; }
.foot-brand img { width: 36px; height: 36px; }
.legal { grid-column: 1 / -1; border-top: 1px solid var(--night-line); padding-top: 24px; margin-top: 16px; font: 400 12px/1.6 var(--mono); color: #7D899B; }
@media (max-width: 760px) { footer .wrap { grid-template-columns: 1fr; } }

/* Página de preguntas */
.page-head { padding: 72px 0 40px; }
.page-head h1 { font-size: clamp(36px, 5vw, 56px); margin: 12px 0 16px; }
.faq-page { padding: 24px 0 120px; }
.faq-layout { display: grid; grid-template-columns: 240px 1fr; gap: 56px; align-items: start; }
.toc { position: sticky; top: 92px; display: grid; gap: 4px; }
.toc a { color: var(--ink-2); text-decoration: none; padding: 6px 0; font-size: 15px; }
.toc a:hover { color: var(--brand); }
@media (max-width: 860px) { .faq-layout { grid-template-columns: 1fr; } .toc { position: static; display: flex; flex-wrap: wrap; gap: 8px; } .toc a { border: 1px solid var(--line); border-radius: 999px; padding: 6px 14px; } }