/* ============================================================
   DIVA — Atmospheric Deep Tech design system
   Built from scratch · deep-space cool dark + neon cyan accent
   ============================================================ */

:root {
  /* surfaces */
  --bg:        #05070d;
  --bg-1:      #080b14;
  --bg-2:      #0b101e;
  --bg-3:      #0e1626;
  --panel:     rgba(13, 20, 36, 0.55);
  --panel-solid: #0a0f1c;

  /* lines */
  --line:        rgba(126, 156, 198, 0.10);
  --line-soft:   rgba(126, 156, 198, 0.055);
  --line-strong: rgba(126, 170, 220, 0.20);

  /* accents — cyan primary, emerald + orange punctual */
  --cyan:      #34d6ee;
  --cyan-2:    #22d3ee;
  --cyan-deep: #0e7d93;
  --emerald:   #34d399;
  --orange:    #fb923c;
  --violet:    #8b7cf6;

  /* glows */
  --cyan-glow: rgba(52, 214, 238, 0.55);

  /* text */
  --text:   #e9eef7;
  --muted:  #9aa8bf;
  --faint:  #62718a;

  /* type */
  --display: 'Space Grotesk', system-ui, sans-serif;
  --mono: 'JetBrains Mono', ui-monospace, monospace;

  /* the live accent (driven by Tweaks) */
  --accent: var(--cyan);
  --accent-glow: var(--cyan-glow);

  --maxw: 1280px;
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; scroll-padding-top: 96px; }

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: var(--display);
  font-size: 17px;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
  overflow-x: hidden;
}

/* faint atmospheric vignette + grain over the whole page */
body::before {
  content: "";
  position: fixed;
  inset: 0;
  pointer-events: none;
  z-index: 0;
  background:
    radial-gradient(120% 80% at 50% -10%, rgba(34, 211, 238, 0.06), transparent 55%),
    radial-gradient(90% 60% at 100% 100%, rgba(52, 211, 153, 0.04), transparent 60%);
}

/* optional engineering grid texture (toggled via .grid-on on body) */
body.grid-on::after {
  content: "";
  position: fixed;
  inset: 0;
  pointer-events: none;
  z-index: 0;
  opacity: 0.5;
  background-image:
    linear-gradient(var(--line-soft) 1px, transparent 1px),
    linear-gradient(90deg, var(--line-soft) 1px, transparent 1px);
  background-size: 64px 64px;
  mask-image: radial-gradient(120% 100% at 50% 0%, #000 30%, transparent 90%);
}

#root { position: relative; z-index: 1; }

h1, h2, h3, h4 { font-weight: 600; letter-spacing: -0.02em; margin: 0; line-height: 1.05; }

a { color: inherit; text-decoration: none; }

::selection { background: var(--accent); color: #04121a; }

.wrap { max-width: var(--maxw); margin: 0 auto; padding: 0 40px; }

/* ---- shared atoms ---- */
.eyebrow {
  font-family: var(--mono);
  font-size: 12px;
  letter-spacing: 0.32em;
  text-transform: uppercase;
  color: var(--accent);
  display: inline-flex;
  align-items: center;
  gap: 10px;
}
.eyebrow::before {
  content: "";
  width: 22px; height: 1px;
  background: var(--accent);
  opacity: 0.7;
}

.mono { font-family: var(--mono); }

.btn {
  font-family: var(--mono);
  font-size: 13px;
  letter-spacing: 0.06em;
  border: 1px solid var(--line-strong);
  background: transparent;
  color: var(--text);
  padding: 13px 22px;
  cursor: pointer;
  display: inline-flex;
  align-items: center;
  gap: 10px;
  transition: all 0.25s cubic-bezier(0.4,0,0.2,1);
  border-radius: 2px;
}
.btn:hover { border-color: var(--accent); color: var(--accent); background: rgba(52,214,238,0.05); }

.btn-primary {
  background: var(--accent);
  color: #03121a;
  border-color: var(--accent);
  font-weight: 500;
  box-shadow: 0 0 0 1px var(--accent), 0 8px 30px -8px var(--accent-glow);
}
.btn-primary:hover {
  background: var(--accent);
  color: #03121a;
  filter: brightness(1.1);
  box-shadow: 0 0 0 1px var(--accent), 0 10px 40px -6px var(--accent-glow);
}

/* section scaffolding */
.section { position: relative; padding: 130px 0; }
.section-label {
  font-family: var(--mono);
  font-size: 12px;
  letter-spacing: 0.3em;
  color: var(--faint);
  text-transform: uppercase;
}

/* reveal on scroll — base state is ALWAYS visible (entrance is a progressive
   enhancement applied via Web Animations API in JS, which fails safe if the
   animation clock never advances). */
.reveal { opacity: 1; }

.divider-line { height: 1px; background: linear-gradient(90deg, transparent, var(--line-strong) 30%, var(--line-strong) 70%, transparent); }

@media (max-width: 820px) {
  .wrap { padding: 0 22px; }
  .section { padding: 86px 0; }
  body { font-size: 16px; }
}
@media (max-width: 560px) {
  .wrap { padding: 0 18px; }
  .section { padding: 64px 0; }
  .btn { padding: 12px 18px; }
  html { scroll-padding-top: 80px; }
}