/* ============================================================
   SynPETic — Navigation + HUD chrome
   ============================================================ */

/* ---------- Top nav ---------- */

.nav {
  position: fixed;
  top: 0; left: 0; right: 0;
  z-index: var(--z-nav);
  padding: 1.1rem var(--gutter);
  display: flex; align-items: center; justify-content: space-between;
  background: linear-gradient(to bottom, rgba(6,6,10,0.85) 0%, rgba(6,6,10,0) 100%);
  /* backdrop-filter is NOT applied here — it would create a containing block
     for any descendant with position:fixed (e.g. the open mobile menu),
     trapping the overlay inside .nav's small auto-height box. Use a child
     pseudo-element instead so the blur effect stays but the spec carve-out
     doesn't pollute the descendant containing-block. */
  transition: background 260ms var(--ease-out-quart);
}
.nav::before {
  content: "";
  position: absolute;
  inset: 0;
  z-index: -1;
  pointer-events: none;
  backdrop-filter: blur(0px);
  -webkit-backdrop-filter: blur(0px);
  transition: backdrop-filter 260ms var(--ease-out-quart),
              -webkit-backdrop-filter 260ms var(--ease-out-quart);
}
.nav.is-scrolled {
  background: rgba(6, 6, 10, 0.75);
  border-bottom: 1px solid var(--rule);
}
.nav.is-scrolled::before {
  backdrop-filter: blur(16px) saturate(140%);
  -webkit-backdrop-filter: blur(16px) saturate(140%);
}

.brand {
  display: inline-flex; align-items: center; gap: 0.65rem;
  font-family: var(--font-mono);
  font-size: 0.82rem;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--ink-900);
}
.brand-mark {
  width: 28px; height: 28px;
  display: grid; place-items: center;
  position: relative;
}
.brand-mark svg { width: 100%; height: 100%; }
.brand-mark::after {
  content: "";
  position: absolute;
  inset: -4px;
  border: 1px solid var(--cyan-500);
  opacity: 0.5;
  border-radius: 99px;
  animation: brand-pulse 2.8s ease-in-out infinite;
}
@keyframes brand-pulse {
  0%, 100% { transform: scale(0.9); opacity: 0.4; }
  50% { transform: scale(1.1); opacity: 0.15; }
}
.brand strong { color: var(--ink-900); font-weight: 600; letter-spacing: 0.06em; }
.brand small {
  color: var(--cyan-400);
  font-size: 0.62rem;
  letter-spacing: 0.32em;
  border-left: 1px solid var(--rule-strong);
  padding-left: 0.65rem;
  margin-left: 0.2rem;
}

/* Primary nav */
.nav-menu {
  display: flex; align-items: center; gap: 0.25rem;
}
.nav-menu .nav-group {
  position: relative;
}
.nav-link {
  display: inline-flex; align-items: center; gap: 0.4rem;
  padding: 0.55rem 0.9rem;
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--ink-800);
  position: relative;
  border-radius: var(--r-sharp);
  transition: color 200ms var(--ease-out-quart);
}
.nav-link::after {
  content: ""; position: absolute; left: 0.9rem; right: 0.9rem; bottom: 0.35rem;
  height: 1px; background: var(--cyan-500); transform: scaleX(0); transform-origin: left;
  transition: transform 260ms var(--ease-out-quart);
}
.nav-link:hover { color: var(--ink-900); }
.nav-link.is-active { color: var(--cyan-400); }
.nav-link.is-active::after,
.nav-link:hover::after { transform: scaleX(1); }
.nav-link .caret { font-size: 0.6rem; opacity: 0.5; }

.nav-drop {
  position: absolute;
  top: calc(100% + 0.4rem);
  left: 0;
  min-width: 19rem;
  background: rgba(11, 11, 18, 0.92);
  backdrop-filter: blur(18px) saturate(140%);
  border: 1px solid var(--rule-strong);
  padding: 0.6rem;
  display: grid;
  gap: 0.15rem;
  opacity: 0; visibility: hidden;
  transform: translateY(6px);
  transition: opacity 220ms var(--ease-out-quart), transform 220ms var(--ease-out-quart), visibility 220ms;
}
.nav-group:hover .nav-drop,
.nav-group:focus-within .nav-drop { opacity: 1; visibility: visible; transform: translateY(0); }

.nav-drop a {
  display: flex; align-items: baseline; gap: 0.6rem;
  padding: 0.6rem 0.8rem;
  font-family: var(--font-sans);
  font-size: 0.86rem;
  color: var(--ink-800);
  border-left: 2px solid transparent;
  transition: background 180ms, border-color 180ms, color 180ms;
}
.nav-drop a small {
  margin-left: auto;
  font-family: var(--font-mono);
  font-size: 0.62rem;
  color: var(--fg-dim);
  letter-spacing: 0.18em;
}
.nav-drop a:hover {
  background: rgba(255,255,255,0.03);
  color: var(--cyan-400);
  border-left-color: var(--cyan-500);
}

/* Mobile burger */
.nav-burger {
  display: none;
  width: 38px; height: 38px;
  border: 1px solid var(--rule-strong);
}
.nav-burger span {
  display: block;
  width: 18px; height: 1px;
  background: var(--ink-900);
  margin: 4px auto;
  transition: transform 220ms var(--ease-out-quart);
}

@media (max-width: 920px) {
  .nav-menu { display: none; }
  .nav-burger { display: inline-flex; align-items: center; justify-content: center; flex-direction: column; }
  .nav-menu.is-open {
    display: grid; gap: 0;
    position: fixed; inset: 0; padding: 5rem 1.5rem 2rem;
    background: rgba(6,6,10,0.97);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    align-content: start;
    overflow-y: auto;
    z-index: var(--z-modal);
  }
  .nav-menu.is-open .nav-group { width: 100%; border-bottom: 1px solid var(--rule); }
  .nav-menu.is-open .nav-link { padding: 1rem 0; font-size: 0.85rem; width: 100%; }
  .nav-menu.is-open .nav-drop {
    position: static; opacity: 1; visibility: visible; transform: none;
    background: transparent; backdrop-filter: none; border: 0;
    padding: 0 0 1rem 1rem; min-width: 100%;
  }
}

/* ---------- HUD telemetry corners ---------- */

.hud {
  position: fixed;
  z-index: var(--z-hud);
  pointer-events: none;
  font-family: var(--font-mono);
  font-size: 0.66rem;
  letter-spacing: 0.18em;
  color: var(--ink-800);
  text-transform: uppercase;
}
.hud-left { bottom: 1.5rem; left: 1.5rem; }
.hud-right { top: 6rem; right: 1.5rem; text-align: right; }

.hud-row {
  display: grid;
  grid-template-columns: 6.5rem 1fr;
  align-items: baseline;
  gap: 0.6rem;
  padding: 0.18rem 0;
}
.hud-right .hud-row { grid-template-columns: 1fr 6.5rem; }

.hud-row .k { color: var(--fg-dim); font-size: 0.6rem; }
.hud-row .v { color: var(--ink-900); }
.hud-row .v .acc { color: var(--cyan-400); }
.hud-row .v .live { color: var(--cellular-green); }

.hud-bracket {
  display: inline-block;
  font-size: 0.62rem;
  color: var(--cyan-500);
  margin-right: 0.4rem;
}
.hud-right .hud-bracket { margin-right: 0; margin-left: 0.4rem; }

@media (max-width: 720px) {
  .hud { display: none; }
}

/* ---------- Footer ---------- */

.foot {
  position: relative;
  padding: var(--space-9) 0 var(--space-6);
  border-top: 1px solid var(--rule);
  background: linear-gradient(to bottom, var(--ink-050), var(--ink-000));
}
.foot-grid {
  display: grid;
  grid-template-columns: 1.4fr repeat(3, 1fr);
  gap: var(--space-7);
}
@media (max-width: 880px) {
  .foot-grid { grid-template-columns: 1fr 1fr; }
}
@media (max-width: 540px) {
  .foot-grid { grid-template-columns: 1fr; }
}
.foot h4 {
  font-family: var(--font-mono);
  font-size: 0.7rem;
  letter-spacing: 0.22em;
  text-transform: uppercase;
  color: var(--fg-muted);
  margin-bottom: 1rem;
}
.foot ul { list-style: none; display: grid; gap: 0.55rem; }
.foot a { color: var(--ink-800); font-size: 0.92rem; transition: color 200ms; }
.foot a:hover { color: var(--cyan-400); }

.foot-brand { max-width: 24rem; }
.foot-blurb {
  margin-top: 1.1rem;
  font-size: 0.95rem;
  line-height: 1.65;
  color: var(--fg-muted);
  max-width: 24rem;
}
.foot-blurb em { font-style: italic; color: var(--cyan-400); }

.foot-bottom {
  margin-top: var(--space-8);
  padding-top: var(--space-5);
  border-top: 1px solid var(--rule);
  display: flex; justify-content: space-between; align-items: center;
  font-family: var(--font-mono); font-size: 0.7rem;
  color: var(--fg-dim); letter-spacing: 0.16em; text-transform: uppercase;
  gap: 1rem; flex-wrap: wrap;
}
.foot-bottom a:hover { color: var(--cyan-400); }
.foot-bottom .cc {
  display: inline-flex; align-items: center; gap: 0.5rem;
  padding: 0.3rem 0.7rem;
  border: 1px solid var(--rule);
}

/* ---------- Custom cursor ---------- */

.cursor {
  position: fixed; top: 0; left: 0;
  width: 28px; height: 28px;
  border: 1px solid var(--cyan-500);
  border-radius: 99px;
  pointer-events: none;
  z-index: var(--z-cursor);
  transform: translate(-50%, -50%);
  mix-blend-mode: difference;
  transition: width 200ms var(--ease-out-quart), height 200ms var(--ease-out-quart),
              background 200ms var(--ease-out-quart);
}
.cursor.is-hover { width: 56px; height: 56px; background: rgba(0,245,255,0.1); }
.cursor.is-down { width: 18px; height: 18px; background: var(--cyan-500); }

@media (pointer: coarse) {
  .cursor { display: none; }
}

/* ---------- Page transition curtain ---------- */

.curtain {
  position: fixed; inset: 0;
  background: linear-gradient(180deg, var(--ink-000) 0%, var(--ink-050) 100%);
  z-index: var(--z-modal);
  pointer-events: none;
  transform: translateY(100%);
  transition: transform 720ms var(--ease-out-expo);
  overflow: hidden;
}
.curtain.is-up { transform: translateY(0); }
.curtain.is-out { transform: translateY(-100%); }
.curtain-stamp {
  position: absolute;
  top: 50%; left: 50%;
  transform: translate(-50%, -50%);
  font-family: var(--font-mono);
  font-size: 0.78rem;
  letter-spacing: 0.32em;
  text-transform: uppercase;
  color: var(--cyan-400);
  opacity: 0;
  animation: stamp-pulse 1.2s ease-out;
}
.curtain.is-up .curtain-stamp { animation: stamp-pulse 1.2s var(--ease-out-quart); }
@keyframes stamp-pulse {
  0% { opacity: 0; letter-spacing: 0.6em; }
  40% { opacity: 1; letter-spacing: 0.32em; }
  100% { opacity: 0; letter-spacing: 0.2em; }
}
/* Cyan sweep bar */
.curtain-bar {
  position: absolute;
  left: 0; right: 0;
  top: 50%;
  height: 1px;
  background: linear-gradient(90deg, transparent 0%, var(--cyan-500) 50%, transparent 100%);
  opacity: 0;
  transform: scaleX(0);
  transform-origin: center;
}
.curtain.is-up .curtain-bar {
  animation: curtain-bar 720ms var(--ease-out-expo) forwards;
}
@keyframes curtain-bar {
  0% { opacity: 0; transform: scaleX(0); }
  40% { opacity: 1; transform: scaleX(1); }
  100% { opacity: 0; transform: scaleX(1); }
}