* { box-sizing: border-box; }

html, body {
  margin: 0;
  padding: 0;
  min-height: 100%;
  background: var(--bg);
  color: var(--signal);
  font-family: var(--font-mono);
  font-size: 15px;
  line-height: 1.5;
}

body {
  position: relative;
  overflow-x: hidden;
  transition: background var(--transition-slow), color var(--transition-slow);
}

/* ---- Ambient overlay layers ---- */
.overlay-layer {
  position: fixed;
  inset: 0;
  pointer-events: none;
  z-index: 5;
  mix-blend-mode: screen;
}
.overlay-scanlines { opacity: 0.10; background: url("/assets/overlays/scanlines.png") repeat; background-size: 100% 4px; }
.overlay-vignette { opacity: 0.55; background: url("/assets/overlays/vignette.png") center/cover no-repeat; mix-blend-mode: multiply; }
.overlay-static { opacity: 0.03; background: url("/assets/overlays/static.png") repeat; animation: static-shift 1.4s steps(2) infinite; }

@keyframes static-shift {
  0% { transform: translate(0,0); }
  50% { transform: translate(-1px, 1px); }
  100% { transform: translate(1px, -1px); }
}
@media (prefers-reduced-motion: reduce) {
  .overlay-static { animation: none; opacity: 0.02; }
}

.glitch-flash {
  animation: glitch-flash 220ms steps(3) 1;
}
@keyframes glitch-flash {
  0% { transform: translateX(0); filter: none; }
  30% { transform: translateX(-2px); filter: hue-rotate(20deg); }
  60% { transform: translateX(2px); }
  100% { transform: translateX(0); filter: none; }
}
@media (prefers-reduced-motion: reduce) {
  .glitch-flash { animation: none; }
}

/* ---- Boot / warning screen ---- */
#boot-screen {
  position: fixed;
  inset: 0;
  z-index: 100;
  background: var(--bg);
  display: flex;
  align-items: center;
  justify-content: center;
  padding: var(--space-4);
}
#boot-screen.hidden { display: none; }
.boot-panel {
  max-width: 620px;
  border: 1px solid var(--border);
  background: var(--panel);
  padding: var(--space-4);
}
.boot-panel h1 {
  font-size: 1rem;
  letter-spacing: 0.12em;
  margin: 0 0 var(--space-2);
  color: var(--bright);
}
.boot-line { margin: 0 0 var(--space-1); letter-spacing: 0.04em; }
.boot-warning {
  margin-top: var(--space-3);
  padding: var(--space-2);
  border: 1px solid var(--border);
  color: var(--bright);
  font-size: 0.85rem;
}
.boot-actions { display: flex; gap: var(--space-2); margin-top: var(--space-4); flex-wrap: wrap; }
#disconnect-message { margin-top: var(--space-2); font-size: 0.85rem; min-height: 1.2em; }

/* ---- Buttons / inputs ---- */
button, input[type="text"] {
  font-family: var(--font-mono);
  background: var(--panel);
  color: var(--signal);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 10px 14px;
  font-size: 0.9rem;
  letter-spacing: 0.04em;
}
button { cursor: pointer; text-transform: uppercase; transition: background var(--transition-fast), color var(--transition-fast); }
button:hover { background: var(--border); color: var(--bg); }
button:focus-visible, input:focus-visible, a:focus-visible, [tabindex]:focus-visible {
  outline: 2px solid var(--bright);
  outline-offset: 2px;
}
input[type="text"] { width: 100%; }
input::placeholder { color: var(--border); }

/* ---- Header / nav ---- */
header.app-header {
  position: sticky;
  top: 0;
  z-index: 10;
  background: color-mix(in srgb, var(--bg) 92%, transparent);
  border-bottom: 1px solid var(--border);
  backdrop-filter: blur(2px);
}
.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-3);
  padding: var(--space-2) var(--space-3);
  max-width: 1100px;
  margin: 0 auto;
  flex-wrap: wrap;
}
.brand { display: flex; align-items: center; gap: var(--space-2); }
.brand img { height: 32px; width: 32px; }
.brand-text { font-size: 0.78rem; letter-spacing: 0.1em; color: var(--bright); line-height: 1.2; }
.alert-bar {
  width: 100%;
  font-size: 0.72rem;
  letter-spacing: 0.08em;
  color: var(--bright);
  text-align: center;
  padding: 2px 0;
}

nav.main-nav {
  display: flex;
  gap: var(--space-1);
  flex-wrap: wrap;
  padding: 0 var(--space-3) var(--space-2);
  max-width: 1100px;
  margin: 0 auto;
}
.nav-item {
  background: transparent;
  border: 1px solid transparent;
  padding: 6px 10px;
  font-size: 0.78rem;
}
.nav-item.active { border-color: var(--border); color: var(--bright); }

/* ---- Page layout ---- */
main { max-width: 1100px; margin: 0 auto; padding: var(--space-4) var(--space-3) var(--space-5); position: relative; z-index: 1; }
.page { display: none; }
.page.active-page { display: block; }
.page-title { font-size: 1rem; letter-spacing: 0.1em; color: var(--bright); margin: 0 0 var(--space-3); text-transform: uppercase; }
.page-intro { max-width: 640px; font-size: 0.88rem; opacity: 0.9; margin-bottom: var(--space-4); }

.panel {
  border: 1px solid var(--border);
  background: var(--panel);
  padding: var(--space-3);
  margin-bottom: var(--space-3);
}

.system-note { font-size: 0.72rem; opacity: 0.75; letter-spacing: 0.05em; }

footer.app-footer {
  border-top: 1px solid var(--border);
  padding: var(--space-4) var(--space-3);
  font-size: 0.7rem;
  opacity: 0.7;
  text-align: center;
  position: relative;
  z-index: 1;
}
footer.app-footer a { color: var(--signal); }

/* ---- Mobile ---- */
@media (max-width: 480px) {
  body { font-size: 14px; }
  main { padding: var(--space-3) var(--space-2) var(--space-4); }
  .header-inner { padding: var(--space-2); }
}