/* ============================================================
   Sensor-Proof — "untraceable / steganography" page
   Vanilla, system fonts, no build. Shares the brand system.
   ============================================================ */

:root {
  --bg: #ffffff;
  --surface: #f8fafc;
  --surface-2: #f1f5f9;
  --ink: #0f172a;
  --ink-soft: #334155;
  --muted: #64748b;
  --line: #e2e8f0;
  --brand: #2563eb;
  --brand-strong: #1d4ed8;
  --brand-soft: #eff4ff;
  --signal: #10b981;
  --signal-strong: #059669;
  --warn: #f59e0b;
  --navy: #0b1220;
  --navy-2: #0f1c33;

  --radius: 14px;
  --radius-pill: 999px;
  --shadow-sm: 0 1px 2px rgba(15, 23, 42, .06), 0 1px 3px rgba(15, 23, 42, .1);
  --shadow: 0 10px 30px -12px rgba(15, 23, 42, .25);
  --shadow-lg: 0 40px 80px -28px rgba(2, 8, 23, .65);
  --maxw: 1140px;
  --font: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, "Helvetica Neue", sans-serif;
  --mono: ui-monospace, SFMono-Regular, "SF Mono", Menlo, Consolas, "Liberation Mono", monospace;
}

*, *::before, *::after { box-sizing: border-box; }
* { margin: 0; }
html { scroll-behavior: smooth; -webkit-text-size-adjust: 100%; }
body { font-family: var(--font); color: var(--ink); background: var(--bg); line-height: 1.6; -webkit-font-smoothing: antialiased; text-rendering: optimizeLegibility; }
img, svg, canvas { display: block; max-width: 100%; }
a { color: inherit; text-decoration: none; }
h1, h2, h3, h4 { line-height: 1.15; letter-spacing: -0.02em; font-weight: 700; }
.mono { font-family: var(--mono); font-variant-numeric: tabular-nums; }
:focus-visible { outline: 3px solid var(--brand); outline-offset: 2px; border-radius: 4px; }

.skip-link { position: absolute; left: 12px; top: -48px; z-index: 100; background: var(--ink); color: #fff; padding: 10px 14px; border-radius: 8px; transition: top .15s ease; }
.skip-link:focus { top: 12px; }
.wrap { width: 100%; max-width: var(--maxw); margin-inline: auto; padding-inline: clamp(18px, 5vw, 32px); }

.dot { width: 9px; height: 9px; border-radius: 50%; display: inline-block; flex: 0 0 auto; }
.dot-signal { background: var(--signal); box-shadow: 0 0 0 3px rgba(16, 185, 129, .18); }
.pulse { animation: pulse 2s ease-out infinite; }
@keyframes pulse { 0% { box-shadow: 0 0 0 0 rgba(16, 185, 129, .5); } 70% { box-shadow: 0 0 0 9px rgba(16, 185, 129, 0); } 100% { box-shadow: 0 0 0 0 rgba(16, 185, 129, 0); } }

/* buttons */
.btn { display: inline-flex; align-items: center; justify-content: center; gap: .5em; font-weight: 600; font-size: .95rem; line-height: 1; cursor: pointer; padding: .72em 1.15em; border-radius: var(--radius-pill); border: 1px solid transparent; transition: transform .12s ease, background .15s ease, box-shadow .15s ease, border-color .15s ease; white-space: nowrap; }
.btn:active { transform: translateY(1px); }
.btn:disabled { opacity: .45; cursor: not-allowed; }
.btn-lg { font-size: 1rem; padding: .9em 1.5em; }
.btn-primary { background: var(--brand); color: #fff; box-shadow: var(--shadow-sm); }
.btn-primary:hover:not(:disabled) { background: var(--brand-strong); box-shadow: var(--shadow); }
.btn-outline { color: #fff; border-color: rgba(255, 255, 255, .3); background: rgba(255, 255, 255, .04); }
.btn-outline:hover { background: rgba(255, 255, 255, .12); border-color: rgba(255, 255, 255, .55); }
.btn-outline-ink { color: var(--brand-strong); border-color: #c7d2fe; background: #fff; }
.btn-outline-ink:hover:not(:disabled) { background: var(--brand-soft); }
.btn-ghost-ink { color: var(--ink-soft); background: transparent; }
.btn-ghost-ink:hover:not(:disabled) { background: var(--surface-2); }

/* header */
.site-header { position: sticky; top: 0; z-index: 50; background: rgba(255, 255, 255, .82); backdrop-filter: saturate(1.4) blur(10px); border-bottom: 1px solid var(--line); }
.header-inner { display: flex; align-items: center; gap: 1.5rem; height: 64px; }
.brand { display: inline-flex; align-items: center; gap: .55rem; font-weight: 700; letter-spacing: -.02em; }
.brand-name { font-size: 1.06rem; }
.nav { display: none; gap: 1.4rem; margin-left: .5rem; margin-right: auto; }
.nav a { color: var(--ink-soft); font-size: .94rem; font-weight: 500; padding: .3rem 0; border-bottom: 2px solid transparent; }
.nav a:hover { color: var(--ink); border-bottom-color: var(--brand); }
.header-cta { margin-left: auto; }

/* hero */
.hero { position: relative; color: #e8eefc; overflow: hidden; background: radial-gradient(900px 500px at 80% -10%, rgba(37, 99, 235, .35), transparent 60%), radial-gradient(700px 500px at 10% 110%, rgba(16, 185, 129, .16), transparent 55%), linear-gradient(180deg, var(--navy), var(--navy-2)); }
.hero::before { content: ""; position: absolute; inset: 0; opacity: .5; pointer-events: none; background-image: linear-gradient(rgba(255, 255, 255, .04) 1px, transparent 1px), linear-gradient(90deg, rgba(255, 255, 255, .04) 1px, transparent 1px); background-size: 44px 44px; -webkit-mask-image: radial-gradient(120% 90% at 50% 0%, #000 40%, transparent 78%); mask-image: radial-gradient(120% 90% at 50% 0%, #000 40%, transparent 78%); }
.hero::after { content: ""; position: absolute; inset: 0; z-index: 0; pointer-events: none; background-image: url("assets/images/hero-ambient-1536.webp"); background-image: image-set(url("assets/images/hero-ambient-1536.avif") type("image/avif"), url("assets/images/hero-ambient-1536.webp") type("image/webp")); background-size: cover; background-position: 80% 60%; opacity: .5; }
.hero-grid { position: relative; z-index: 1; display: grid; gap: clamp(2.2rem, 5vw, 4rem); padding-block: clamp(3.5rem, 8vw, 6rem) clamp(3.5rem, 7vw, 5.5rem); align-items: center; }
.eyebrow { display: inline-flex; align-items: center; gap: .5rem; font-size: .82rem; font-weight: 600; letter-spacing: .02em; color: #aec6f5; background: rgba(255, 255, 255, .06); border: 1px solid rgba(255, 255, 255, .12); padding: .35rem .7rem; border-radius: var(--radius-pill); margin-bottom: 1.1rem; }
.hero h1 { font-size: clamp(2.3rem, 6vw, 3.6rem); color: #fff; max-width: 15ch; margin-bottom: 1.1rem; }
.lede { font-size: clamp(1.05rem, 2.4vw, 1.22rem); color: #c4d2ee; max-width: 48ch; }
.lede strong { color: #fff; font-weight: 600; }
.lede em { color: #d7e2f7; font-style: italic; }
.hero-actions { display: flex; flex-wrap: wrap; gap: .75rem; margin-top: 1.8rem; }
.hero-note { margin-top: 1.1rem; font-size: .85rem; color: #8ea4cc; }

/* cloak panel */
.cloak { background: #0e1a30; color: #dbe6fb; border: 1px solid rgba(255, 255, 255, .1); border-radius: 18px; padding: 1.25rem; box-shadow: var(--shadow-lg); width: 100%; max-width: 440px; justify-self: center; }
.cloak-io { display: grid; grid-template-columns: 1fr auto 1fr; align-items: center; gap: .6rem; }
.cloak-card { background: rgba(255, 255, 255, .05); border: 1px solid rgba(255, 255, 255, .1); border-radius: 12px; padding: .8rem; min-height: 96px; display: flex; flex-direction: column; gap: .5rem; justify-content: center; }
.cloak-tag { font-size: .68rem; text-transform: uppercase; letter-spacing: .08em; color: #8ea4cc; }
.cloak-card code { font-size: .82rem; color: #aec6f5; word-break: break-all; }
.carrier-img { position: relative; display: block; height: 54px; border-radius: 8px; overflow: hidden; background: linear-gradient(135deg, #123 0%, #1b5e57 45%, #2563eb 100%); background-size: 200% 200%; }
.scanline { position: absolute; left: 0; right: 0; height: 14px; top: -14px; background: linear-gradient(180deg, transparent, rgba(16, 185, 129, .7), transparent); animation: scan 2.6s ease-in-out infinite; }
@keyframes scan { 0% { top: -14px; } 60%, 100% { top: 54px; } }
.cloak-stream { display: flex; flex-direction: column; align-items: center; gap: 2px; font-family: var(--mono); font-size: .8rem; color: var(--signal); overflow: hidden; height: 96px; justify-content: center; }
.cloak-stream .bit { opacity: .25; animation: bitflow 1.6s linear infinite; }
.cloak-stream .bit:nth-child(2n) { color: #5eead4; }
.cloak-stream .bit:nth-child(1) { animation-delay: 0s; } .cloak-stream .bit:nth-child(2) { animation-delay: .2s; } .cloak-stream .bit:nth-child(3) { animation-delay: .4s; } .cloak-stream .bit:nth-child(4) { animation-delay: .6s; } .cloak-stream .bit:nth-child(5) { animation-delay: .8s; } .cloak-stream .bit:nth-child(6) { animation-delay: 1s; } .cloak-stream .bit:nth-child(7) { animation-delay: 1.2s; } .cloak-stream .bit:nth-child(8) { animation-delay: 1.4s; }
@keyframes bitflow { 0% { opacity: .15; transform: translateY(-4px); } 50% { opacity: 1; } 100% { opacity: .15; transform: translateY(4px); } }
.cloak-status { display: flex; align-items: center; gap: .5rem; margin-top: 1rem; font-size: .9rem; }
.cloak-status strong { color: var(--signal); }
.cloak-foot { margin-top: .7rem; padding-top: .7rem; border-top: 1px solid rgba(255, 255, 255, .08); font-size: .74rem; color: #7d8eb0; text-align: center; }

/* trust strip */
.strip { background: var(--navy-2); color: #cdd9f2; border-bottom: 1px solid rgba(255, 255, 255, .06); }
.strip-grid { display: grid; grid-template-columns: repeat(2, 1fr); gap: 1.5rem 1rem; padding-block: 1.6rem; }
.strip-grid > div { display: flex; flex-direction: column; gap: .15rem; }
.strip-num { font-size: 1.5rem; font-weight: 700; color: #fff; }
.strip-cap { font-size: .82rem; color: #8ea4cc; }

/* sections */
.section { padding-block: clamp(3.5rem, 8vw, 6rem); }
.section-alt { background: var(--surface); }
.section-dark { background: linear-gradient(180deg, var(--navy-2), var(--navy)); color: #dbe6fb; }
.section-head { max-width: 60ch; margin-bottom: clamp(2rem, 4vw, 3rem); }
.kicker { font-size: .8rem; font-weight: 700; letter-spacing: .08em; text-transform: uppercase; color: var(--brand); margin-bottom: .6rem; }
.kicker-light { color: #6ee7b7; }
.section h2 { font-size: clamp(1.7rem, 4vw, 2.5rem); }
.section-dark h2 { color: #fff; }
.section-sub { margin-top: .9rem; font-size: 1.06rem; color: var(--muted); }
.section-dark .section-sub { color: #b6c4e0; }
.section-sub em { color: var(--ink-soft); font-style: italic; }
.section-dark .section-sub em { color: #e2e8f5; }

/* steps */
.steps { list-style: none; padding: 0; display: grid; grid-template-columns: 1fr; gap: 1.4rem; }
.step { background: var(--bg); border: 1px solid var(--line); border-radius: var(--radius); padding: 1.6rem; box-shadow: var(--shadow-sm); }
.step-num { display: inline-flex; align-items: center; justify-content: center; width: 2.4rem; height: 2.4rem; border-radius: 12px; background: var(--brand-soft); color: var(--brand-strong); font-weight: 700; margin-bottom: 1rem; }
.step h3 { font-size: 1.2rem; margin-bottom: .4rem; }
.step p { color: var(--muted); font-size: .97rem; }

/* demo */
.demo { display: grid; gap: 1.6rem; grid-template-columns: 1fr; background: var(--bg); border: 1px solid var(--line); border-radius: 18px; padding: clamp(1.2rem, 3vw, 2rem); box-shadow: var(--shadow); }
.demo-controls label { display: block; font-weight: 600; font-size: .9rem; margin-bottom: .5rem; }
.demo-controls textarea { width: 100%; font: inherit; font-size: 1rem; padding: .8rem .9rem; border: 1px solid var(--line); border-radius: 12px; resize: vertical; background: var(--surface); color: var(--ink); }
.demo-controls textarea:focus-visible { background: #fff; }
.demo-buttons { display: flex; flex-wrap: wrap; gap: .5rem; margin-top: .9rem; }
.demo-buttons .btn { font-size: .88rem; padding: .6em .9em; }
.demo-status { margin-top: 1rem; font-size: .85rem; color: var(--ink-soft); line-height: 1.45; min-height: 2.5em; }
.demo-reveal { margin-top: .6rem; padding: .7rem .9rem; border-radius: 10px; background: var(--brand-soft); color: var(--brand-strong); font-weight: 600; font-size: .92rem; }
.demo-stage { display: grid; grid-template-columns: 1fr 1fr; gap: 1rem; align-items: start; }
.canvas-wrap { margin: 0; text-align: center; }
.canvas-wrap canvas { width: 100%; max-width: 240px; height: auto; aspect-ratio: 1; margin: 0 auto; border-radius: 12px; border: 1px solid var(--line); background: var(--surface-2); image-rendering: auto; }
.canvas-wrap figcaption { margin-top: .5rem; font-size: .82rem; font-weight: 600; color: var(--muted); }
#stego-cap { color: var(--signal-strong); }
.demo-foot { margin-top: 2rem; text-align: center; font-size: 1.05rem; color: var(--ink-soft); max-width: 60ch; margin-inline: auto; }
.demo-foot strong { color: var(--ink); }

/* features / use cases */
.feature-grid { display: grid; grid-template-columns: 1fr; gap: 1.1rem; }
.feature { padding: 1.4rem; border-radius: var(--radius); border: 1px solid var(--line); background: var(--bg); transition: border-color .15s ease, box-shadow .15s ease, transform .15s ease; }
.feature:hover { border-color: #c7d2fe; box-shadow: var(--shadow); transform: translateY(-2px); }
.feature-ico { width: 2.6rem; height: 2.6rem; display: grid; place-items: center; border-radius: 12px; background: linear-gradient(135deg, var(--brand-soft), #e7fff5); color: var(--brand-strong); font-size: 1.25rem; margin-bottom: .9rem; }
.feature h3 { font-size: 1.1rem; margin-bottom: .35rem; }
.feature p { color: var(--muted); font-size: .94rem; }

/* security grid */
.sec-grid { display: grid; grid-template-columns: 1fr; gap: 1.1rem; }
.sec-item { padding: 1.4rem; border-radius: var(--radius); background: rgba(255, 255, 255, .04); border: 1px solid rgba(255, 255, 255, .1); }
.sec-item h3 { font-size: 1.1rem; color: #fff; margin-bottom: .35rem; }
.sec-item p { color: #b6c4e0; font-size: .94rem; }
.responsible { margin-top: 2rem; padding: 1rem 1.2rem; border-left: 3px solid var(--signal); background: rgba(16, 185, 129, .08); border-radius: 0 10px 10px 0; color: #d9f6e9; font-size: .95rem; }

/* CTA */
.cta { background: linear-gradient(135deg, var(--brand), #4f46e5); color: #fff; }
.cta-inner { text-align: center; padding-block: clamp(3.5rem, 8vw, 6rem); max-width: 680px; }
.cta h2 { font-size: clamp(1.9rem, 4.5vw, 2.7rem); }
.cta p { margin-top: .8rem; font-size: 1.1rem; color: #e0e7ff; }
.cta-actions { margin-top: 1.8rem; }
.cta .btn-primary { background: var(--navy); }
.cta .btn-primary:hover { background: #060c18; }
.cta-tagline { margin-top: 1.6rem; font-size: 1.15rem; color: #eef2ff; }
.cta-tagline strong { color: #fff; }

/* footer */
.site-footer { background: var(--navy); color: #aebbd6; padding-block: clamp(2.5rem, 5vw, 3.5rem) 1.5rem; }
.footer-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 2rem 1rem; }
.footer-brand { grid-column: 1 / -1; }
.footer-brand .brand-name { color: #fff; }
.footer-brand p { margin-top: .6rem; font-size: .9rem; color: #8294b5; max-width: 30ch; }
.footer-col h4 { color: #fff; font-size: .82rem; text-transform: uppercase; letter-spacing: .06em; margin-bottom: .8rem; }
.footer-col a { display: block; padding: .28rem 0; font-size: .92rem; color: #aebbd6; }
.footer-col a:hover { color: #fff; }
.footer-base { display: flex; flex-wrap: wrap; gap: .8rem; justify-content: space-between; align-items: center; margin-top: 2.5rem; padding-top: 1.3rem; border-top: 1px solid rgba(255, 255, 255, .08); font-size: .82rem; color: #7d8eb0; }
.footer-live { display: inline-flex; align-items: center; gap: .5rem; }

/* reveal */
.reveal { opacity: 0; transform: translateY(16px); transition: opacity .6s ease, transform .6s ease; }
.reveal.in-view { opacity: 1; transform: none; }

/* responsive */
@media (min-width: 560px) {
  .feature-grid { grid-template-columns: repeat(2, 1fr); }
  .strip-grid { grid-template-columns: repeat(4, 1fr); }
  .sec-grid { grid-template-columns: repeat(2, 1fr); }
  .footer-grid { grid-template-columns: 2fr 1fr 1fr 1fr; }
  .footer-brand { grid-column: auto; }
}
@media (min-width: 880px) {
  .nav { display: flex; }
  .hero-grid { grid-template-columns: 1.05fr .95fr; }
  .steps { grid-template-columns: repeat(3, 1fr); }
  .feature-grid { grid-template-columns: repeat(3, 1fr); }
  .sec-grid { grid-template-columns: repeat(4, 1fr); }
  .demo { grid-template-columns: 1fr 1fr; align-items: center; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after { animation-duration: .001ms !important; animation-iteration-count: 1 !important; transition-duration: .001ms !important; }
  .reveal { opacity: 1; transform: none; }
  .scanline { display: none; }
}