:root {
  --bg: #000000;
  --scan: rgba(0, 255, 204, 0.08);
  --glow: #00ffcc;
  --glow-soft: rgba(0, 255, 204, 0.35);
  --txt: #c8fff3;
  --txt-dim: #87f5e4;
  --accent: #00ffcc;
  --accent-2: #18a3a6;
  --danger: #ff3d81;
}

* { box-sizing: border-box; }

html, body {
  height: 100%;
  margin: 0;
}

body {
  background: radial-gradient(1000px 600px at 50% 10%, #031715 0%, #010605 40%, #000 100%);
  color: var(--txt);
  font-family: ui-sans-serif, system-ui, -apple-system, Segoe UI, Roboto, "Helvetica Neue", Arial, "Noto Sans", "Apple Color Emoji", "Segoe UI Emoji";
  overflow: hidden;
}

/* Grid shell */
.hud-wrap {
  height: 100%;
  display: grid;
  grid-template-rows: auto 1fr auto;
  gap: 12px;
  padding: 18px clamp(16px, 4vw, 32px);
  position: relative;
}

/* Subtle scanlines */
.hud-wrap::before {
  content: "";
  position: absolute;
  inset: 0;
  background: repeating-linear-gradient(
    to bottom,
    transparent 0px,
    transparent 2px,
    var(--scan) 3px,
    transparent 4px
  );
  pointer-events: none;
  mix-blend-mode: screen;
}

/* Header */
.hud-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  border: 1px solid var(--glow-soft);
  padding: 10px 14px;
  backdrop-filter: blur(6px);
  background: linear-gradient(180deg, rgba(0,0,0,0.45), rgba(0,0,0,0.25));
  box-shadow: 0 0 24px rgba(0, 255, 204, 0.06), inset 0 0 32px rgba(0,255,204,0.04);
}

.brand {
  display: flex;
  align-items: center;
  gap: 10px;
  letter-spacing: 0.06em;
  text-transform: uppercase;
}

.brand-pulse {
  width: 10px;
  height: 10px;
  border: 1px solid var(--accent);
  box-shadow: 0 0 12px var(--glow);
  border-radius: 2px;
  animation: pulse 1.8s ease-in-out infinite;
}

.brand-text {
  color: var(--txt);
  text-shadow: 0 0 8px var(--glow-soft);
}

.hud-nav {
  display: flex;
  gap: 10px;
}

.hud-btn {
  background: transparent;
  border: 1px solid var(--glow-soft);
  color: var(--txt);
  padding: 8px 14px;
  cursor: pointer;
  transition: 130ms ease;
  letter-spacing: 0.04em;
  text-transform: uppercase;
}

.hud-btn:hover {
  border-color: var(--accent);
  box-shadow: 0 0 12px var(--glow-soft), inset 0 0 12px rgba(0,255,204,0.08);
  color: white;
}

/* Main area */
.hud-main {
  display: grid;
  grid-template-columns: 1.2fr 1fr;
  gap: 14px;
  height: 100%;
}

.panel {
  border: 1px solid var(--glow-soft);
  background: linear-gradient(180deg, rgba(0,18,16,0.45), rgba(0,0,0,0.35));
  box-shadow: inset 0 0 24px rgba(0,255,204,0.05), 0 0 24px rgba(0,255,204,0.05);
  padding: clamp(16px, 3vw, 24px);
  position: relative;
  overflow: hidden;
}

.panel::after {
  content: "";
  position: absolute;
  inset: -2px;
  border: 1px solid rgba(0,255,204,0.08);
  pointer-events: none;
}

/* Intro content */
#intro-panel {
  display: grid;
  place-content: center;
  text-align: center;
  gap: 8px;
}

.hud-text {
  font-size: clamp(22px, 4vw, 44px);
  color: #dffff8;
  text-shadow:
    0 0 6px rgba(0,255,204,0.6),
    0 0 30px rgba(0,255,204,0.25);
  letter-spacing: 0.02em;
}

.hud-sub {
  color: var(--txt-dim);
  font-size: clamp(14px, 2vw, 16px);
  opacity: 0.85;
}

/* Metrics panel */
.metrics {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 12px;
  align-content: start;
}

.metric {
  border: 1px dashed rgba(0,255,204,0.25);
  padding: 12px;
  background: rgba(0,0,0,0.3);
}

.metric .label {
  display: block;
  font-size: 12px;
  text-transform: uppercase;
  color: var(--txt-dim);
  letter-spacing: 0.08em;
}

.metric .value {
  font-size: 18px;
  color: var(--txt);
  text-shadow: 0 0 8px rgba(0,255,204,0.2);
}

/* Footer */
.hud-footer {
  display: flex;
  align-items: center;
  justify-content: center;
  border: 1px solid var(--glow-soft);
  padding: 10px;
  color: var(--txt-dim);
  background: linear-gradient(180deg, rgba(0,0,0,0.35), rgba(0,0,0,0.2));
}

.foot-text { letter-spacing: 0.06em; }

/* Glitch effect class */
.glitch-active .hud-text {
  animation: glitch-burst 0.35s steps(10, end);
}

/* Animations */
@keyframes pulse {
  0%, 100% { box-shadow: 0 0 10px var(--glow); background: transparent; }
  50% { box-shadow: 0 0 22px #35ffd8; background: var(--accent-2); }
}

@keyframes glitch-burst {
  0%   { transform: translate(0); filter: drop-shadow(0 0 0 var(--accent)); }
  20%  { transform: translate(-6px, 4px) skewX(1deg); text-shadow: -2px 0 #ff006e, 2px 0 #00fff5; }
  40%  { transform: translate(5px, -5px) skewX(-1deg); text-shadow: -1px 0 #00fff5, 1px 0 #ff006e; }
  60%  { transform: translate(-5px, 3px); text-shadow: -3px 0 #ff006e, 3px 0 #00fff5; }
  80%  { transform: translate(4px, -4px); text-shadow: -1px 0 #00fff5, 1px 0 #ff006e; }
  100% { transform: translate(0); text-shadow: 0 0 6px rgba(0,255,204,0.6), 0 0 30px rgba(0,255,204,0.25); }
}

/* Responsive */
@media (max-width: 900px) {
  .hud-main { grid-template-columns: 1fr; }
}