/* ============================================================
   TENSEN LABS · Quiet Infrastructure — shared design system
   Used by login.html and products/relayos.html.
   ============================================================ */

:root{
  --ink-00:#0b0b0c;
  --ink-05:#101012;
  --ink-10:#16161a;
  --ink-20:#202024;
  --ink-30:#2a2a30;
  --ink-40:#3a3a42;
  --ink-50:#5b5b66;
  --ink-60:#7a7a86;
  --ink-70:#a0a0ab;
  --ink-80:#c8c8cf;
  --ink-90:#e6e6ea;
  --paper:#f1efe9;

  --sage:#a8b89a;
  --sage-dim:#7c8a72;
  --rose:#c97a7a;

  --serif:'Instrument Serif', 'Times New Roman', serif;
  --sans:'Inter Tight', -apple-system, BlinkMacSystemFont, sans-serif;
  --mono:'JetBrains Mono', ui-monospace, monospace;

  --gutter: clamp(20px, 4vw, 56px);
  --t-fast: 220ms cubic-bezier(.2,.7,.2,1);
  --t-med: 480ms cubic-bezier(.2,.7,.2,1);
}

*,*::before,*::after{box-sizing:border-box;margin:0;padding:0}
html,body{background:var(--ink-00);color:var(--ink-90)}
html{-webkit-text-size-adjust:100%;font-size:16px}
body{
  font-family:var(--sans);
  font-weight:400;line-height:1.55;letter-spacing:-0.005em;
  -webkit-font-smoothing:antialiased;-moz-osx-font-smoothing:grayscale;
  overflow-x:hidden;
}
a{color:inherit;text-decoration:none}
img,svg{display:block;max-width:100%}
button{font:inherit;color:inherit;background:none;border:0;cursor:pointer}
::selection{background:var(--sage);color:var(--ink-00)}

body::before{
  content:"";position:fixed;inset:0;z-index:-1;pointer-events:none;
  background:
    radial-gradient(120% 80% at 0% 0%, #14140f 0%, transparent 55%),
    radial-gradient(110% 70% at 100% 100%, #0d1014 0%, transparent 60%),
    var(--ink-00);
}
body::after{
  content:"";position:fixed;inset:0;z-index:-1;pointer-events:none;
  opacity:.05;mix-blend-mode:overlay;
  background-image:url("data:image/svg+xml;utf8,<svg xmlns='http://www.w3.org/2000/svg' width='160' height='160'><filter id='n'><feTurbulence type='fractalNoise' baseFrequency='0.9' numOctaves='2' stitchTiles='stitch'/></filter><rect width='100%25' height='100%25' filter='url(%23n)' opacity='0.6'/></svg>");
}

.shell{width:100%;max-width:1480px;margin:0 auto;padding:0 var(--gutter)}
.serif{font-family:var(--serif);font-weight:400;letter-spacing:-0.01em}
.serif-i{font-family:var(--serif);font-style:italic;letter-spacing:-0.01em}
.mono{font-family:var(--mono)}

.nav{
  position:fixed;top:0;left:0;right:0;z-index:50;
  padding:18px 0;
  transition:background var(--t-med),border-color var(--t-med);
  border-bottom:1px solid transparent;
}
.nav.is-scrolled{
  background:rgba(11,11,12,.78);
  backdrop-filter:blur(8px);-webkit-backdrop-filter:blur(8px);
  border-bottom-color:var(--ink-20);
}
.nav-inner{display:flex;align-items:center;justify-content:space-between;gap:32px}
.brand{display:inline-flex;align-items:baseline;gap:10px;font-weight:500;font-size:15px}
.brand .glyph{
  display:inline-block;width:10px;height:10px;
  border:1px solid var(--ink-80);transform:rotate(45deg);
  position:relative;top:1px;
}
.brand .glyph::before{content:"";position:absolute;inset:2px;background:var(--sage)}
.brand .sub{
  font-family:var(--mono);font-size:10px;text-transform:uppercase;letter-spacing:.22em;
  color:var(--ink-60);margin-left:4px;
}
.brand .product{
  font-family:var(--serif);font-style:italic;font-size:18px;
  color:var(--ink-70);margin-left:14px;padding-left:14px;
  border-left:1px solid var(--ink-30);line-height:1;
}
.nav-links{display:flex;align-items:center;gap:36px;list-style:none}
.nav-links a{font-size:13px;color:var(--ink-70);transition:color var(--t-fast)}
.nav-links a:hover{color:var(--ink-90)}
.nav-links a[data-cta]{
  display:inline-flex;align-items:center;gap:8px;
  padding:8px 14px;border:1px solid var(--ink-30);border-radius:999px;
  color:var(--ink-90);
  transition:border-color var(--t-fast),background var(--t-fast);
}
.nav-links a[data-cta]:hover{border-color:var(--ink-50);background:var(--ink-10)}
.nav-links a[data-cta] .arr{transition:transform var(--t-fast)}
.nav-links a[data-cta]:hover .arr{transform:translateX(3px)}

.eyebrow{
  font-family:var(--mono);font-size:11px;text-transform:uppercase;
  letter-spacing:.18em;color:var(--ink-60);
  display:inline-flex;align-items:center;gap:10px;
}
.eyebrow .num{color:var(--ink-50)}
.rule-h{height:1px;background:var(--ink-20);border:0;width:100%}

.cta-line{
  display:inline-flex;align-items:center;gap:14px;
  padding:14px 0;font-size:15px;color:var(--ink-90);
  border-top:1px solid var(--ink-30);border-bottom:1px solid var(--ink-30);
  width:280px;justify-content:space-between;
  transition:color var(--t-fast),border-color var(--t-fast);
}
.cta-line .arr{font-family:var(--mono);font-size:13px;transition:transform var(--t-fast)}
.cta-line:hover{color:var(--sage);border-color:var(--sage-dim)}
.cta-line:hover .arr{transform:translateX(6px)}

.cta-secondary{
  font-family:var(--mono);font-size:11px;text-transform:uppercase;
  letter-spacing:.18em;color:var(--ink-60);
  display:inline-flex;align-items:center;gap:8px;
  transition:color var(--t-fast);
}
.cta-secondary:hover{color:var(--ink-90)}

.live-dot{
  display:inline-block;width:6px;height:6px;border-radius:50%;
  background:var(--sage);position:relative;
}
.live-dot::after{
  content:"";position:absolute;inset:-4px;border-radius:50%;
  border:1px solid var(--sage);opacity:.5;
  animation:qi-pulse 2.4s ease-out infinite;
}
@keyframes qi-pulse{
  0%{transform:scale(.8);opacity:.5}
  80%{transform:scale(2.2);opacity:0}
  100%{opacity:0}
}

.section-head{
  display:grid;grid-template-columns:repeat(12, minmax(0,1fr));
  column-gap:24px;margin-bottom:80px;align-items:end;
}
.section-head .index{
  grid-column:1 / span 3;
  font-family:var(--mono);font-size:11px;text-transform:uppercase;
  letter-spacing:.18em;color:var(--ink-60);
  display:flex;align-items:baseline;gap:10px;
}
.section-head .index .n{color:var(--ink-50)}
.section-head .title{
  grid-column:5 / span 7;
  font-family:var(--serif);font-size:clamp(36px,5.5vw,80px);
  line-height:1;letter-spacing:-0.02em;color:var(--ink-90);
  text-wrap:balance;
}
.section-head .title em{font-style:italic;color:var(--ink-70)}

.foot{
  padding:32px 0 40px;border-top:1px solid var(--ink-20);
  font-family:var(--mono);font-size:11px;text-transform:uppercase;
  letter-spacing:.18em;color:var(--ink-50);
}
.foot-inner{display:flex;justify-content:space-between;align-items:center;gap:24px}
.foot a{transition:color var(--t-fast)}
.foot a:hover{color:var(--ink-90)}
.foot .links{display:flex;gap:28px;list-style:none}

.reveal{opacity:0;transform:translateY(12px);
  transition:opacity 700ms cubic-bezier(.2,.7,.2,1),transform 700ms cubic-bezier(.2,.7,.2,1)}
.reveal.in{opacity:1;transform:none}
.reveal[data-d="1"]{transition-delay:80ms}
.reveal[data-d="2"]{transition-delay:160ms}
.reveal[data-d="3"]{transition-delay:240ms}
.reveal[data-d="4"]{transition-delay:320ms}
@media (prefers-reduced-motion:reduce){
  .reveal{opacity:1;transform:none;transition:none}
  .live-dot::after{animation:none}
}

@media (max-width:980px){
  .nav-links li.hide-md{display:none}
  .section-head{margin-bottom:48px}
  .section-head .index{grid-column:1/-1}
  .section-head .title{grid-column:1/-1;margin-top:18px}
  .foot-inner{flex-direction:column;gap:14px;align-items:flex-start}
}