/* landing page. the picture is the page; everything laid on it is either
   type on the open sky or a sheet of smoked glass. */

/* ---------- header: a bar of glass that floats free of the edges ---------- */
.top { position: sticky; top: 0; z-index: 20; padding: 10px 0 0; color: var(--on-sky); }
.top .bar {
  height: 54px; display: flex; align-items: center; justify-content: space-between; gap: 1rem;
  padding: 0 0.45rem 0 1.15rem; border-radius: 999px;
  border: 1px solid transparent; background: transparent;
  transition: background 600ms var(--ease), border-color 600ms var(--ease), box-shadow 600ms var(--ease), backdrop-filter 600ms var(--ease);
}
/* once the hero has scrolled under it, the bar takes the glass */
.top.solid .bar {
  background: rgba(10, 12, 18, 0.55); border-color: var(--line-strong);
  box-shadow: var(--shadow), inset 0 1px 0 rgba(255, 255, 255, 0.08);
  backdrop-filter: blur(var(--glass-blur)) saturate(140%); -webkit-backdrop-filter: blur(var(--glass-blur)) saturate(140%);
}
.top .wordmark { color: var(--on-sky); }
.top .wordmark span { color: var(--on-sky-soft); }
.top .wordmark::before { --c: var(--on-sky); }

.top nav { display: flex; gap: 0.15rem; align-items: center; }
.top nav a {
  position: relative; border: 0; padding: 0.45rem 0.7rem; border-radius: 999px;
  color: var(--on-sky-soft); font-size: 0.82rem; letter-spacing: 0.05em;
  transition: color 320ms var(--ease);
}
/* the underline is a hairline that draws from the left, and stays for the section in view */
.top nav a::after {
  content: ""; position: absolute; left: 0.7rem; right: 0.7rem; bottom: 0.2rem; height: 1px;
  background: currentColor; transform: scaleX(0); transform-origin: left center; opacity: 0.8;
  transition: transform 460ms var(--ease);
}
.top nav a:hover, .top nav a.current { color: var(--on-sky); }
.top nav a:hover::after, .top nav a.current::after { transform: scaleX(1); }

.topactions { display: flex; align-items: center; gap: 0.35rem; }
.top a.enter {
  display: inline-flex; align-items: center; gap: 0.5rem; height: 40px; padding: 0 1.05rem 0 1.15rem;
  border: 1px solid rgba(244, 239, 231, 0.45); border-radius: 999px; background: rgba(244, 239, 231, 0.08);
  color: var(--on-sky); font-size: 0.85rem; letter-spacing: 0.05em;
  transition: background 320ms var(--ease), color 320ms var(--ease), border-color 320ms var(--ease);
}
.top a.enter .arr { display: inline-block; transition: transform 320ms var(--ease); font-weight: 400; }
.top a.enter:hover { background: var(--ring); color: var(--void); border-color: var(--ring); box-shadow: 0 0 30px -8px rgba(244,239,231,0.5); }
.top a.enter:hover .arr { transform: translateX(3px); }

/* the phone menu: two hairlines that fold into one */
.top .menu { display: none; width: 40px; height: 40px; padding: 0; border: 1px solid rgba(244,239,231,0.3); background: rgba(244,239,231,0.06); border-radius: 999px; position: relative; min-height: 0; }
.top .menu span { position: absolute; left: 12px; right: 12px; height: 1px; background: var(--on-sky); transition: transform 420ms var(--ease), opacity 420ms var(--ease); }
.top .menu span:first-child { top: 16px; }
.top .menu span:last-child { top: 23px; }
.top.open .menu span:first-child { transform: translateY(3.5px) rotate(45deg); }
.top.open .menu span:last-child { transform: translateY(-3.5px) rotate(-45deg); }
@media (max-width: 860px) {
  .top .menu { display: block; }
  .top nav {
    position: absolute; left: var(--gutter); right: var(--gutter); top: calc(100% + 8px);
    flex-direction: column; align-items: stretch; gap: 0.1rem; padding: 0.6rem;
    /* the one opaque surface: a night-black card. glass here would show the
       hero through the labels, and a blur nested inside the bar's blur does
       not render cleanly */
    border-radius: 18px; border: 1px solid var(--line-strong); background: #0b0d13;
    box-shadow: var(--shadow);
    opacity: 0; transform: translateY(-6px); pointer-events: none;
    transition: opacity 360ms var(--ease), transform 360ms var(--ease);
  }
  .top.open nav { opacity: 1; transform: none; pointer-events: auto; }
  .top nav a { padding: 0.75rem 0.9rem; font-size: 0.95rem; }
  .top nav a::after { left: 0.9rem; right: auto; width: 18px; bottom: 0.55rem; }
  .top a.enter { padding: 0 0.9rem; }
  .top a.enter .arr { display: none; }
}
@media (max-width: 380px) { .top a.enter { display: none; } }

/* ---------- hero: type on the open sky ---------- */
.hero {
  position: relative;
  min-height: calc(100dvh - 64px);
  display: grid; place-items: center;
  padding: clamp(4rem, 12vh, 9rem) 0 clamp(5rem, 14vh, 10rem);
  isolation: isolate;
}
/* a breath of the sky's shadow behind the text column, so the cascade's
   highlights never cut through the letters */
.hero::before {
  content: ""; position: absolute; inset: -10% 0 0 0; z-index: 0; pointer-events: none;
  background: radial-gradient(70% 80% at 22% 50%, rgba(4, 5, 10, 0.5), rgba(4, 5, 10, 0) 70%);
}
.hero .wrap { position: relative; z-index: 1; }
.hero .eyebrow { color: var(--on-sky-soft); }
.hero h1 {
  max-width: 13ch; font-weight: 200; line-height: 1.04; letter-spacing: -0.018em;
  color: var(--on-sky); text-shadow: 0 2px 30px rgba(4, 5, 10, 0.7);
}
.hero h1 em { font-style: normal; color: var(--on-sky-soft); }
.hero .lede { margin-top: 1.8rem; font-size: clamp(1.02rem, 1.5vw, 1.15rem); max-width: 46ch; color: var(--on-sky-soft); text-shadow: 0 1px 18px rgba(4, 5, 10, 0.7); }
.hero .actions { margin-top: 2.4rem; display: flex; gap: 0.8rem; flex-wrap: wrap; align-items: center; }
.hero .actions button.primary:hover { transform: translateY(-1px); }
.hero .actions button.ghost { color: var(--on-sky-soft); text-decoration: underline; text-underline-offset: 6px; text-decoration-color: rgba(255,255,255,0.35); }
.hero .actions button.ghost:hover { color: var(--on-sky); background: transparent; text-decoration-color: var(--on-sky); }
.hero .status { margin-top: 3.2rem; display: flex; gap: 0.6rem; flex-wrap: wrap; }
.hero .pill { color: var(--on-sky-soft); border-color: rgba(244,239,231,0.28); background: rgba(4, 5, 10, 0.35); }
.hero .signal { z-index: 0; mask-image: radial-gradient(circle at 50% 50%, black 0%, transparent 70%); -webkit-mask-image: radial-gradient(circle at 50% 50%, black 0%, transparent 70%); }
/* the hero arrives more slowly than the rest of the page */
.hero .reveal { transition-duration: 1300ms; transition-delay: calc(var(--i, 0) * 170ms + 120ms); transform: translateY(18px); }

/* the cue: one thread of the cascade, falling, at the bottom of the hero */
.cue { position: absolute; left: 50%; bottom: 1.6rem; z-index: 1; width: 1px; height: 56px; border: 0; overflow: hidden; transform: translateX(-50%); opacity: 0.7; }
.cue span { position: absolute; left: 0; top: 0; width: 1px; height: 100%; background: linear-gradient(180deg, transparent, var(--on-sky) 40%, transparent); animation: fall 3.4s var(--ease) infinite; }
@keyframes fall { 0% { transform: translateY(-100%); } 55% { transform: translateY(100%); } 100% { transform: translateY(100%); } }

/* ---------- sections: sheets of glass on the field ---------- */
section.block { padding: clamp(1.4rem, 4vh, 3rem) 0; scroll-margin-top: 84px; }
section.block .wrap {
  display: grid; grid-template-columns: minmax(0, 1fr) minmax(0, 1.4fr); gap: clamp(2rem, 6vw, 6rem); align-items: start;
  background: var(--surface); border: 1px solid var(--line); border-radius: 18px;
  padding: clamp(1.6rem, 4vw, 3.2rem); box-shadow: var(--shadow), inset 0 1px 0 rgba(255,255,255,0.07);
  backdrop-filter: blur(var(--glass-blur)) saturate(140%); -webkit-backdrop-filter: blur(var(--glass-blur)) saturate(140%);
}
/* the heading holds still while its column of text passes */
section.block .head { position: sticky; top: 92px; }
section.block h2 { max-width: 16ch; }
@media (max-width: 800px) { section.block .wrap { grid-template-columns: 1fr; } section.block .head { position: static; } }

/* steps: a numbered thread */
.steps { list-style: none; margin: 0; padding: 0; counter-reset: s; display: grid; gap: 0; }
.steps li { position: relative; padding: 0 0 1.4rem 3rem; counter-increment: s; }
.steps li:last-child { padding-bottom: 0; }
.steps li::before {
  content: counter(s, decimal-leading-zero);
  position: absolute; left: 0; top: 0.15rem;
  font-family: var(--mono); font-size: 0.72rem; letter-spacing: 0.12em; color: var(--muted);
}
.steps li::after { content: ""; position: absolute; left: 0.55rem; top: 1.6rem; bottom: 0.4rem; width: 1px; background: linear-gradient(180deg, var(--line-strong), transparent); }
.steps li:last-child::after { display: none; }
.steps li strong { display: block; font-weight: 300; font-size: 1.05rem; color: var(--text); margin-bottom: 0.25rem; }
.steps li p { font-size: 0.95rem; }

.facts { display: grid; gap: 0; }
.fact { display: grid; grid-template-columns: 150px 1fr; gap: 1rem; padding: 0.95rem 0; border-bottom: 1px solid var(--line); font-size: 0.95rem; }
.fact:last-child { border-bottom: 0; }
.fact .k { color: var(--muted); font-size: 0.82rem; letter-spacing: 0.06em; padding-top: 0.1rem; }
.fact .v { color: var(--text-soft); }
.fact .v.mono { color: var(--text); }
@media (max-width: 480px) { .fact { grid-template-columns: 1fr; gap: 0.2rem; } }

.never { list-style: none; margin: 0; padding: 0; display: grid; gap: 0; }
.never li { padding: 0.8rem 0; border-bottom: 1px solid var(--line); color: var(--text-soft); display: flex; gap: 1rem; align-items: baseline; }
.never li:last-child { border-bottom: 0; }
.never li::before { content: ""; flex: 0 0 18px; height: 1px; background: var(--line-strong); transform: translateY(-0.35em); }

/* the pairing demonstration: two devices, one code, drawn in css */
.pairdemo { position: relative; display: grid; grid-template-columns: 1fr auto 1fr; align-items: center; gap: 1rem; padding: 1.4rem; background: var(--bg-deep); border: 1px solid var(--line); border-radius: 14px; }
.device { border: 1px solid var(--line-strong); border-radius: 18px; aspect-ratio: 9 / 16; max-width: 130px; width: 100%; justify-self: center; position: relative; overflow: hidden; background: linear-gradient(180deg, var(--void) 0%, var(--sky-deep) 55%, var(--ember-deep) 100%); transition: border-color 600ms var(--ease), box-shadow 600ms var(--ease); }
.device::after { content: ""; position: absolute; left: 50%; top: 8px; width: 32px; height: 4px; border-radius: 3px; background: rgba(255,255,255,0.7); transform: translateX(-50%); }
.device .glyph { position: absolute; inset: 30% 22%; border: 1px solid rgba(255,255,255,0.7); border-radius: 2px; }
.device .glyph::before, .device .glyph::after { content: ""; position: absolute; width: 30%; height: 30%; border: 1px solid rgba(255,255,255,0.7); }
.device .glyph::before { left: 10%; top: 10%; }
.device .glyph::after { right: 10%; bottom: 10%; }
.device .code { position: absolute; left: 0; right: 0; bottom: 14%; text-align: center; font-family: var(--mono); font-size: 0.7rem; letter-spacing: 0.25em; color: rgba(255,255,255,0.75); transition: color 600ms var(--ease); }
.pairdemo .link { width: clamp(40px, 8vw, 120px); height: 1px; background: linear-gradient(90deg, transparent, var(--line-strong), transparent); position: relative; }
.pairdemo .link::after { content: ""; position: absolute; top: -2px; left: 0; width: 5px; height: 5px; border-radius: 50%; background: var(--dim); animation: travel 3.2s var(--ease) infinite; }
@keyframes travel { 0% { left: 0; opacity: 0; } 15% { opacity: 1; } 85% { opacity: 1; } 100% { left: 100%; opacity: 0; } }
.pairdemo.trust .device .code { color: var(--accent); }
.pairdemo.trust .link::after { background: var(--accent); box-shadow: 0 0 10px var(--accent-glow); }
.pairdemo.trust .device { border-color: var(--accent); box-shadow: 0 0 0 3px var(--accent-soft); }

/* ---------- footer: the last sheet, on the field ---------- */
footer { padding: clamp(2rem, 6vh, 4rem) 0 calc(2rem + env(safe-area-inset-bottom)); color: var(--text-soft); font-size: 0.88rem; }
footer .foot {
  display: grid; grid-template-columns: minmax(0, 1.5fr) minmax(0, 1fr) minmax(0, 1fr); gap: clamp(1.6rem, 4vw, 3.5rem);
  background: var(--surface); border: 1px solid var(--line); border-radius: 18px;
  padding: clamp(1.6rem, 3.5vw, 2.6rem); box-shadow: var(--shadow), inset 0 1px 0 rgba(255,255,255,0.07);
  backdrop-filter: blur(var(--glass-blur)) saturate(140%); -webkit-backdrop-filter: blur(var(--glass-blur)) saturate(140%);
}
footer .col { display: grid; gap: 0.45rem; align-content: start; }
footer .col .k { color: var(--muted); font-size: 0.75rem; letter-spacing: 0.16em; margin-bottom: 0.4rem; }
footer .col a { border: 0; color: var(--text-soft); width: fit-content; position: relative; }
footer .col a::after { content: ""; position: absolute; left: 0; right: 0; bottom: -2px; height: 1px; background: currentColor; transform: scaleX(0); transform-origin: left; transition: transform 420ms var(--ease); }
footer .col a:hover { color: var(--text); }
footer .col a:hover::after { transform: scaleX(1); }
footer .brand p { margin: 0.8rem 0 1.2rem; font-size: 0.92rem; max-width: 34ch; }
footer .brand .row { gap: 0.9rem; }
footer .ver { color: var(--muted); font-size: 0.8rem; }
footer .fine { display: flex; justify-content: space-between; gap: 1rem; flex-wrap: wrap; margin-top: 1.4rem; padding: 0 0.4rem; color: var(--dim); font-size: 0.78rem; letter-spacing: 0.04em; }
@media (max-width: 760px) { footer .foot { grid-template-columns: 1fr 1fr; } footer .brand { grid-column: 1 / -1; } }
@media (max-width: 440px) { footer .foot { grid-template-columns: 1fr; } }