/* ABYSSAL — cinematic scroll descent */
:root {
  --cyan: #4be7ff;
  --cyan-dim: rgba(75, 231, 255, 0.55);
  --ink: #eaf6fa;
  --ink-dim: rgba(234, 246, 250, 0.6);
  --navy: #061422;
  --black: #000308;
  --hud-border: rgba(75, 231, 255, 0.22);
  --font: "Helvetica Neue", "Inter", "SF Pro Text", Arial, sans-serif;
}

* { margin: 0; padding: 0; box-sizing: border-box; }

html { scroll-behavior: auto; }

body {
  font-family: var(--font);
  background: var(--navy);
  color: var(--ink);
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
}

#scroll-track { position: relative; width: 100%; pointer-events: none; }

/* ---------- Loader ---------- */
#loader {
  position: fixed; inset: 0; z-index: 100;
  background: var(--black);
  display: flex; align-items: center; justify-content: center;
  transition: opacity 0.9s ease, visibility 0.9s;
}
#loader.done { opacity: 0; visibility: hidden; }
.loader-inner { width: min(420px, 80vw); }
.loader-mark {
  font-size: 34px; letter-spacing: 0.55em; font-weight: 300;
  color: var(--ink); margin-bottom: 10px;
}
.loader-sub {
  font-size: 10px; letter-spacing: 0.35em; color: var(--cyan-dim);
  margin-bottom: 42px;
}
.loader-bar {
  height: 1px; background: rgba(255,255,255,0.12); position: relative;
  margin-bottom: 14px;
}
#loader-fill {
  position: absolute; left: 0; top: -0.5px; height: 2px; width: 0%;
  background: var(--cyan); box-shadow: 0 0 12px var(--cyan);
  transition: width 0.2s linear;
}
.loader-status {
  display: flex; justify-content: space-between;
  font-size: 10px; letter-spacing: 0.3em; color: var(--ink-dim);
}

/* ---------- Canvas & grade ---------- */
#dive {
  position: fixed; inset: 0; width: 100vw; height: 100vh; z-index: 1;
  background: var(--navy);
}
#grade {
  position: fixed; inset: 0; z-index: 2; pointer-events: none;
  background: var(--navy); mix-blend-mode: multiply; opacity: 0;
}
#vignette {
  position: fixed; inset: 0; z-index: 3; pointer-events: none;
  background: radial-gradient(ellipse at center, transparent 52%, rgba(0, 3, 8, 0.55) 100%);
}
#grain {
  position: fixed; inset: -50%; width: 200%; height: 200%; z-index: 4;
  pointer-events: none; opacity: 0.05;
  background-image: url("data:image/svg+xml,%3Csvg viewBox='0 0 256 256' xmlns='http://www.w3.org/2000/svg'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.9' numOctaves='2'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23n)'/%3E%3C/svg%3E");
  animation: grain 0.7s steps(4) infinite;
}
@keyframes grain {
  0% { transform: translate(0,0); } 25% { transform: translate(-2%,1%); }
  50% { transform: translate(1%,-2%); } 75% { transform: translate(-1%,2%); }
  100% { transform: translate(2%,-1%); }
}

/* ---------- HUD ---------- */
#hud-top {
  position: fixed; top: 0; left: 0; right: 0; z-index: 10;
  display: flex; justify-content: space-between; align-items: flex-start;
  padding: 28px 36px;
}
.brand {
  font-size: 19px; letter-spacing: 0.5em; font-weight: 400;
  color: var(--ink); text-decoration: none; cursor: pointer; display: inline-block;
  transition: text-shadow 0.3s ease, color 0.3s ease;
}
.brand:hover { color: var(--cyan); text-shadow: 0 0 18px rgba(75, 231, 255, 0.6); }
.brand-sub { font-size: 9px; letter-spacing: 0.32em; color: var(--cyan-dim); margin-top: 6px; }
.hud-right { display: flex; gap: 28px; }
.hud-cell { display: flex; flex-direction: column; gap: 5px; text-align: right; }
.hud-cell .k { font-size: 8px; letter-spacing: 0.3em; color: var(--ink-dim); }
.hud-cell .v { font-size: 11px; letter-spacing: 0.22em; color: var(--cyan); }

#depth-hud {
  position: fixed; left: 36px; top: 50%; transform: translateY(-50%);
  z-index: 10; width: 130px;
}
.depth-label { font-size: 8px; letter-spacing: 0.35em; color: var(--ink-dim); margin-bottom: 8px; }
.depth-value {
  font-size: 40px; font-weight: 200; letter-spacing: 0.04em;
  font-variant-numeric: tabular-nums; color: var(--ink);
  text-shadow: 0 0 24px rgba(75, 231, 255, 0.35);
}
.depth-unit { font-size: 14px; color: var(--cyan); margin-left: 4px; letter-spacing: 0.2em; }
.depth-rail { display: flex; gap: 10px; margin-top: 20px; height: 220px; }
.rail-track { position: relative; width: 1px; background: rgba(255,255,255,0.15); }
#rail-fill {
  position: absolute; top: 0; left: -0.5px; width: 2px; height: 0%;
  background: linear-gradient(to bottom, transparent, var(--cyan));
}
#rail-dot {
  position: absolute; left: 50%; top: 0%; width: 7px; height: 7px;
  transform: translate(-50%, -50%); border-radius: 50%;
  background: var(--cyan); box-shadow: 0 0 10px var(--cyan);
}
.rail-zones { display: flex; flex-direction: column; justify-content: space-between; }
.rail-zones span {
  font-size: 8px; letter-spacing: 0.25em; color: var(--ink-dim);
  transition: color 0.4s;
}
.rail-zones span.on { color: var(--cyan); }
.zone-label {
  margin-top: 20px; font-size: 11px; letter-spacing: 0.3em; color: var(--cyan);
  border-left: 1px solid var(--hud-border); padding-left: 10px;
}
.hud-micro { margin-top: 10px; font-size: 8px; letter-spacing: 0.22em; color: var(--ink-dim); padding-left: 11px; }

#scroll-cue {
  position: fixed; bottom: 34px; left: 50%; transform: translateX(-50%);
  z-index: 10; text-align: center; transition: opacity 0.6s;
}
#scroll-cue span { font-size: 9px; letter-spacing: 0.4em; color: var(--ink-dim); }
.cue-line {
  width: 1px; height: 44px; margin: 12px auto 0;
  background: linear-gradient(to bottom, var(--cyan), transparent);
  animation: cue 2s ease-in-out infinite;
}
@keyframes cue { 0%,100% { transform: scaleY(0.4); opacity: .4; transform-origin: top; } 50% { transform: scaleY(1); opacity: 1; transform-origin: top; } }

/* ---------- Overlay sections ---------- */
.ov {
  position: fixed; z-index: 8; opacity: 0; pointer-events: none;
  will-change: opacity, transform;
}
#ov-hero { left: 0; right: 0; top: 50%; transform: translateY(-50%); text-align: center; }
.mega {
  font-size: clamp(48px, 9vw, 120px); font-weight: 200; line-height: 1.02;
  letter-spacing: 0.06em;
}
.lede { margin-top: 26px; font-size: 13px; letter-spacing: 0.3em; color: var(--ink-dim); text-transform: uppercase; }

.ov-fact { left: max(190px, 12vw); top: 50%; transform: translateY(-50%); max-width: 520px; }
.ov-fact.right { left: auto; right: 8vw; }
.fact-tag { font-size: 9px; letter-spacing: 0.35em; color: var(--cyan); margin-bottom: 18px; }
.ov h2 { font-size: clamp(30px, 4.4vw, 58px); font-weight: 200; letter-spacing: 0.1em; margin-bottom: 20px; }
.fact { font-size: 16px; line-height: 1.85; color: var(--ink-dim); font-weight: 300; max-width: 44ch; }

.ov-specs { left: max(190px, 12vw); top: 50%; transform: translateY(-50%); max-width: 560px; }
.specs { list-style: none; margin-top: 8px; }
.specs li {
  display: flex; justify-content: space-between; gap: 30px;
  padding: 11px 0; border-bottom: 1px solid rgba(255,255,255,0.08);
  font-size: 11px; letter-spacing: 0.18em;
}
.specs .k { color: var(--ink-dim); }
.specs .v { color: var(--ink); text-align: right; }

.ov-final { left: 0; right: 0; top: 50%; transform: translateY(-50%); text-align: center; }
.offer { font-size: clamp(34px, 5.6vw, 76px) !important; line-height: 1.15; letter-spacing: 0.06em; }
.cta {
  display: inline-block; margin-top: 44px; padding: 18px 46px;
  border: 1px solid var(--cyan); color: var(--cyan); text-decoration: none;
  font-size: 12px; letter-spacing: 0.4em;
  box-shadow: inset 0 0 0 0 var(--cyan), 0 0 30px rgba(75,231,255,0.15);
  transition: all 0.35s ease; pointer-events: auto;
}
.cta:hover { background: var(--cyan); color: var(--black); box-shadow: 0 0 50px rgba(75,231,255,0.5); }
.cta-arrow { margin-left: 8px; }
.fine { margin-top: 34px; font-size: 9px; letter-spacing: 0.28em; color: var(--ink-dim); }

@media (max-width: 760px) {
  #depth-hud { left: 18px; width: 100px; transform: translateY(-50%) scale(0.85); transform-origin: left center; }
  .ov-fact, .ov-fact.right, .ov-specs { left: 20px; right: 20px; max-width: none; }
  #hud-top { padding: 18px 20px; }
}