:root {
  --ocean: #02080f;
  --deep: #061826;
  --teal: #7fe3e0;
  --gold: #f5c451;
  --danger: #e86a5c;
  --text: #d6eceb;
  --dim: #8fb7bd;
  --glass: rgba(127, 227, 224, 0.06);
  --edge: rgba(127, 227, 224, 0.18);
}

* { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; }

body {
  font: 17px/1.7 "Segoe UI", system-ui, -apple-system, Roboto, sans-serif;
  color: var(--text);
  background: linear-gradient(180deg, #0b3a52 0, #08283b 18%, var(--deep) 45%, var(--ocean) 100%) fixed;
  min-height: 100vh;
  overflow-x: hidden;
}

#bubbles { position: fixed; inset: 0; width: 100%; height: 100%; z-index: 0; pointer-events: none; }

/* sunlight from the surface */
body::before {
  content: "";
  position: fixed; inset: 0 0 auto 0; height: 70vh; z-index: 0; pointer-events: none;
  background: radial-gradient(ellipse 70% 100% at 50% -10%, rgba(127, 227, 224, 0.28), transparent 70%);
}

a { color: var(--teal); text-decoration: none; }
a:hover { text-decoration: underline; }

header, main, footer { position: relative; z-index: 1; }

nav {
  display: flex; align-items: center; justify-content: space-between;
  max-width: 980px; margin: 0 auto; padding: 22px 24px;
}
.brand {
  font-weight: 700; letter-spacing: 0.35em; color: #fff; font-size: 15px;
}
.brand:hover { text-decoration: none; }
nav ul { display: flex; gap: 6px; list-style: none; }
nav ul a {
  display: block; padding: 7px 16px; border-radius: 999px; color: var(--dim); font-size: 15px;
  transition: background .2s, color .2s;
}
nav ul a:hover { background: var(--glass); color: #fff; text-decoration: none; }
nav ul a.on { background: var(--glass); color: var(--teal); box-shadow: inset 0 0 0 1px var(--edge); }

.wrap { max-width: 980px; margin: 0 auto; padding: 0 24px; }

/* hero */
.hero { text-align: center; padding: 90px 0 70px; }
.hero h1 {
  font-size: clamp(44px, 10vw, 92px); letter-spacing: 0.22em; padding-left: 0.22em;
  font-weight: 800; color: #fff;
  text-shadow: 0 0 40px rgba(127, 227, 224, 0.55), 0 0 120px rgba(127, 227, 224, 0.25);
}
.hero p.tag { font-size: clamp(18px, 3vw, 24px); color: var(--teal); margin-top: 10px; letter-spacing: 0.04em; }
.hero p.sub { max-width: 560px; margin: 22px auto 0; color: var(--dim); }

.soon {
  margin: 30px 0 6px; padding-left: 0.22em;
  font-size: clamp(26px, 5.5vw, 50px); font-weight: 800; letter-spacing: 0.22em;
  color: #fff;
  text-shadow: 0 0 40px rgba(127, 227, 224, 0.55), 0 0 120px rgba(127, 227, 224, 0.25);
}

.page-title { padding: 56px 0 30px; }
.page-title h1 { font-size: clamp(34px, 6vw, 52px); color: #fff; letter-spacing: 0.04em; }
.page-title p { color: var(--dim); margin-top: 6px; }

.btn {
  display: inline-block; margin-top: 30px; padding: 13px 34px; border-radius: 999px;
  background: linear-gradient(180deg, var(--teal), #4cc3c0); color: #02202a; font-weight: 700;
  letter-spacing: 0.08em; box-shadow: 0 0 30px rgba(127, 227, 224, 0.35);
  transition: transform .2s, box-shadow .2s;
}
.btn:hover { transform: translateY(-2px); box-shadow: 0 0 46px rgba(127, 227, 224, 0.55); text-decoration: none; }

/* sections & cards */
section { padding: 34px 0; }
h2 { font-size: 13px; letter-spacing: 0.3em; text-transform: uppercase; color: var(--gold); margin-bottom: 18px; font-weight: 600; }
h3 { color: #fff; font-size: 19px; margin-bottom: 6px; }
p + p { margin-top: 14px; }

.grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(250px, 1fr)); gap: 18px; }
.card {
  background: var(--glass); border: 1px solid var(--edge); border-radius: 18px; padding: 24px;
  backdrop-filter: blur(8px); -webkit-backdrop-filter: blur(8px);
  transition: transform .25s, border-color .25s;
}
.card:hover { transform: translateY(-4px); border-color: rgba(127, 227, 224, 0.45); }
.card .ico { font-size: 28px; margin-bottom: 10px; display: block; }
.card p { color: var(--dim); font-size: 16px; }

.zones { display: flex; flex-direction: column; gap: 0; border-radius: 18px; overflow: hidden; border: 1px solid var(--edge); }
.zone { display: flex; justify-content: space-between; padding: 14px 22px; font-size: 16px; }
.zone b { color: #fff; font-weight: 600; }
.zone span { color: rgba(255, 255, 255, 0.65); font-variant-numeric: tabular-nums; }
.z1 { background: rgba(60, 170, 190, 0.35); }
.z2 { background: rgba(30, 110, 150, 0.35); }
.z3 { background: rgba(20, 60, 110, 0.4); }
.z4 { background: rgba(12, 30, 70, 0.5); }
.z5 { background: rgba(4, 10, 28, 0.6); }

/* prose pages */
.prose { background: var(--glass); border: 1px solid var(--edge); border-radius: 18px; padding: 8px 32px 28px; }
.prose h2 { margin-top: 28px; }
.prose ul { margin: 12px 0 0 22px; color: var(--dim); }
.prose li { margin-top: 6px; }
.prose p { color: var(--dim); }
.prose strong { color: var(--text); }
.callout {
  border-left: 3px solid var(--gold); background: rgba(245, 196, 81, 0.07);
  padding: 14px 20px; border-radius: 0 12px 12px 0; margin-top: 22px; color: var(--text);
}

details { border-bottom: 1px solid var(--edge); padding: 16px 0; }
details:last-child { border-bottom: 0; }
summary { cursor: pointer; color: #fff; font-weight: 600; list-style: none; display: flex; justify-content: space-between; gap: 12px; }
summary::-webkit-details-marker { display: none; }
summary::after { content: "+"; color: var(--teal); font-size: 22px; line-height: 1; transition: transform .2s; }
details[open] summary::after { transform: rotate(45deg); }
details p { margin-top: 10px; }

footer { text-align: center; padding: 60px 24px 50px; color: var(--dim); font-size: 14px; }
footer nav { justify-content: center; gap: 22px; padding: 0 0 14px; }
footer a { color: var(--dim); }
footer a:hover { color: var(--teal); }

/* depth gauge */
#gauge {
  position: fixed; right: 18px; top: 50%; transform: translateY(-50%); z-index: 2;
  height: 40vh; width: 2px; background: rgba(127, 227, 224, 0.2); pointer-events: none;
}
#gauge i {
  position: absolute; left: -4px; width: 10px; height: 10px; border-radius: 50%;
  background: var(--teal); box-shadow: 0 0 12px var(--teal); top: 0;
}
#gauge b {
  position: absolute; right: 18px; transform: translateY(-50%); top: 0;
  font: 12px ui-monospace, Consolas, monospace; color: var(--teal); white-space: nowrap;
}

.fade { opacity: 0; transform: translateY(18px); transition: opacity .7s, transform .7s; }
.fade.in { opacity: 1; transform: none; }

@media (max-width: 640px) {
  body { font-size: 16px; }
  nav { flex-direction: column; gap: 12px; }
  .prose { padding: 4px 20px 22px; }
  #gauge { display: none; }
  .hero { padding: 60px 0 50px; }
}
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  .fade { opacity: 1; transform: none; transition: none; }
}