/* ==========================================================================
   CHROMA // QUANTUM OPTICS LAB
   Futuristic Generative Compute Engine & Holographic HUD
   ========================================================================== */

:root {
  --neon-cyan: #00f0ff;
  --neon-violet: #b026ff;
  --neon-amber: #ffaa00;
  --neon-emerald: #00ffaa;
  --neon-rose: #ff2a6d;
  
  --hud-bg-core: #03060a;
  --hud-bg-panel: rgba(6, 12, 20, 0.75);
  --hud-bg-elevated: rgba(12, 24, 38, 0.85);
  --hud-border: rgba(0, 240, 255, 0.22);
  --hud-border-bright: rgba(0, 240, 255, 0.6);
  --hud-glow: rgba(0, 240, 255, 0.25);
  
  --text-main: #e2f4ff;
  --text-muted: #5e849e;
  --text-bright: #ffffff;
  
  --font-mono: 'JetBrains Mono', 'Fira Code', 'Courier New', monospace;
  --font-display: 'Rajdhani', 'Orbitron', 'Inter', sans-serif;
}

* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
  -webkit-tap-highlight-color: transparent;
  user-select: none;
}

html, body {
  width: 100%;
  height: 100%;
  overflow: hidden;
  background-color: var(--hud-bg-core);
  color: var(--text-main);
  font-family: var(--font-mono);
  font-size: 13px;
  line-height: 1.4;
}

/* Background Canvas */
#viewportCanvas {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  z-index: 1;
  display: block;
  cursor: crosshair;
}

/* Subtle CRT & Hex Spatial Grid */
.hud-grid-overlay {
  position: absolute;
  inset: 0;
  pointer-events: none;
  z-index: 2;
  background-image: 
    linear-gradient(to right, rgba(0, 240, 255, 0.04) 1px, transparent 1px),
    linear-gradient(to bottom, rgba(0, 240, 255, 0.04) 1px, transparent 1px);
  background-size: 40px 40px;
}

.hud-vignette {
  position: absolute;
  inset: 0;
  pointer-events: none;
  z-index: 3;
  background: radial-gradient(circle at 50% 50%, transparent 55%, rgba(1, 3, 6, 0.85) 100%);
}

/* Interactive UI Layer */
.hud-ui-shell {
  position: absolute;
  inset: 0;
  z-index: 10;
  pointer-events: none;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  padding: 16px 20px;
}

.hud-interactive {
  pointer-events: auto;
}

/* ---------- 1. Top HUD Ribbon ---------- */
.hud-topbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  flex-wrap: wrap;
}

.hud-brand-block {
  display: flex;
  align-items: center;
  gap: 14px;
}

.hud-back-link {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 6px 12px;
  background: var(--hud-bg-panel);
  border: 1px solid var(--hud-border);
  color: var(--text-muted);
  text-decoration: none;
  font-size: 11.5px;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  border-radius: 4px;
  backdrop-filter: blur(12px);
  transition: all 0.2s ease;
}

.hud-back-link:hover {
  color: var(--neon-cyan);
  border-color: var(--neon-cyan);
  background: rgba(0, 240, 255, 0.1);
  box-shadow: 0 0 12px var(--hud-glow);
  transform: translateX(-2px);
}

.hud-title-unit {
  display: flex;
  flex-direction: column;
}

.hud-title-unit h1 {
  font-family: var(--font-display);
  font-size: 1.25rem;
  font-weight: 700;
  letter-spacing: 0.15em;
  color: var(--text-bright);
  text-transform: uppercase;
  display: flex;
  align-items: center;
  gap: 8px;
}

.hud-badge-core {
  font-size: 9.5px;
  padding: 2px 6px;
  background: rgba(0, 240, 255, 0.12);
  border: 1px solid var(--neon-cyan);
  color: var(--neon-cyan);
  border-radius: 2px;
  letter-spacing: 0.12em;
}

.hud-sub-label {
  font-size: 10.5px;
  color: var(--text-muted);
  letter-spacing: 0.08em;
}

/* Top Telemetry Meters */
.hud-telemetry-strip {
  display: flex;
  align-items: center;
  gap: 16px;
  background: var(--hud-bg-panel);
  border: 1px solid var(--hud-border);
  padding: 6px 14px;
  border-radius: 4px;
  backdrop-filter: blur(12px);
}

.hud-tele-item {
  display: flex;
  flex-direction: column;
  gap: 2px;
}

.hud-tele-label {
  font-size: 9px;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.1em;
}

.hud-tele-val {
  font-size: 13px;
  font-weight: 700;
  color: var(--neon-cyan);
  letter-spacing: 0.05em;
}

/* Quick Action Buttons */
.hud-btn-group {
  display: flex;
  align-items: center;
  gap: 8px;
}

.hud-tool-btn {
  background: var(--hud-bg-panel);
  border: 1px solid var(--hud-border);
  color: var(--text-main);
  padding: 7px 12px;
  border-radius: 4px;
  font-family: inherit;
  font-size: 11px;
  letter-spacing: 0.06em;
  cursor: pointer;
  backdrop-filter: blur(12px);
  display: inline-flex;
  align-items: center;
  gap: 6px;
  transition: all 0.15s ease;
}

.hud-tool-btn:hover {
  border-color: var(--neon-cyan);
  color: var(--neon-cyan);
  background: rgba(0, 240, 255, 0.1);
  box-shadow: 0 0 10px var(--hud-glow);
}

.hud-tool-btn.active {
  border-color: var(--neon-cyan);
  background: rgba(0, 240, 255, 0.18);
  color: #fff;
  box-shadow: 0 0 14px var(--hud-glow);
}

/* ---------- 2. Middle Layer: Mode Selector & Control Panel ---------- */
.hud-middle-stage {
  display: flex;
  align-items: flex-end;
  justify-content: space-between;
  gap: 20px;
  flex: 1;
  padding: 16px 0;
}

/* Left: Simulation Modes Floating Rail */
.hud-modes-dock {
  display: flex;
  flex-direction: column;
  gap: 8px;
  background: var(--hud-bg-panel);
  border: 1px solid var(--hud-border);
  border-radius: 8px;
  padding: 12px;
  backdrop-filter: blur(14px);
  width: 220px;
  box-shadow: 0 8px 32px rgba(0, 0, 0, 0.6);
}

.hud-section-header {
  font-size: 10px;
  font-weight: 700;
  color: var(--neon-cyan);
  letter-spacing: 0.14em;
  text-transform: uppercase;
  margin-bottom: 4px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.hud-mode-pill {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 8px 10px;
  background: rgba(6, 16, 26, 0.6);
  border: 1px solid rgba(0, 240, 255, 0.12);
  color: var(--text-muted);
  border-radius: 4px;
  cursor: pointer;
  font-family: inherit;
  font-size: 11px;
  letter-spacing: 0.05em;
  text-align: left;
  transition: all 0.15s ease;
}

.hud-mode-pill:hover {
  color: var(--text-bright);
  background: rgba(0, 240, 255, 0.08);
  border-color: rgba(0, 240, 255, 0.35);
}

.hud-mode-pill.active {
  color: var(--neon-cyan);
  border-color: var(--neon-cyan);
  background: rgba(0, 240, 255, 0.15);
  box-shadow: 0 0 12px var(--hud-glow);
  font-weight: 600;
}

.hud-mode-num {
  font-size: 9.5px;
  opacity: 0.6;
}

/* Right: Holographic Parameter Deck (Collapsible) */
.hud-params-deck {
  display: flex;
  flex-direction: column;
  gap: 12px;
  background: var(--hud-bg-panel);
  border: 1px solid var(--hud-border);
  border-radius: 8px;
  padding: 14px 16px;
  backdrop-filter: blur(14px);
  width: 260px;
  box-shadow: 0 8px 32px rgba(0, 0, 0, 0.6);
  transition: transform 0.25s ease, opacity 0.25s ease;
}

.hud-param-row {
  display: flex;
  flex-direction: column;
  gap: 5px;
}

.hud-param-top {
  display: flex;
  align-items: center;
  justify-content: space-between;
  font-size: 10.5px;
}

.hud-param-label {
  color: var(--text-muted);
  letter-spacing: 0.06em;
  text-transform: uppercase;
}

.hud-param-readout {
  color: var(--neon-cyan);
  font-weight: 700;
}

/* Futuristic Custom Slider */
.hud-slider {
  -webkit-appearance: none;
  appearance: none;
  width: 100%;
  height: 4px;
  background: rgba(0, 240, 255, 0.15);
  border-radius: 2px;
  outline: none;
  cursor: pointer;
}

.hud-slider::-webkit-slider-thumb {
  -webkit-appearance: none;
  appearance: none;
  width: 12px;
  height: 12px;
  border-radius: 2px;
  background: var(--neon-cyan);
  box-shadow: 0 0 8px var(--neon-cyan);
  cursor: pointer;
  transition: transform 0.1s ease;
}

.hud-slider::-webkit-slider-thumb:hover {
  transform: scale(1.25);
}

/* Color Palettes Grid */
.hud-palette-row {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 6px;
  margin-top: 2px;
}

.hud-palette-swatch {
  height: 22px;
  border-radius: 3px;
  border: 1px solid rgba(255, 255, 255, 0.2);
  cursor: pointer;
  transition: all 0.15s ease;
}

.hud-palette-swatch:hover,
.hud-palette-swatch.active {
  border-color: #fff;
  transform: scale(1.08);
  box-shadow: 0 0 8px currentColor;
}

/* ---------- 3. Bottom HUD Deck & Interaction Prompts ---------- */
.hud-bottom-bar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  flex-wrap: wrap;
}

.hud-interaction-hint {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-size: 11px;
  color: var(--text-muted);
  background: var(--hud-bg-panel);
  border: 1px solid var(--hud-border);
  padding: 6px 12px;
  border-radius: 4px;
  backdrop-filter: blur(12px);
}

.hud-kbd-chip {
  background: rgba(0, 240, 255, 0.12);
  border: 1px solid var(--hud-border);
  color: var(--neon-cyan);
  padding: 1px 5px;
  border-radius: 2px;
  font-weight: 700;
  font-size: 10px;
}

.hud-pulse-radar {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--neon-emerald);
  box-shadow: 0 0 8px var(--neon-emerald);
  animation: radarBlink 1.8s infinite ease-in-out;
}

@keyframes radarBlink {
  0%, 100% { opacity: 0.3; transform: scale(0.85); }
  50% { opacity: 1; transform: scale(1.2); }
}

/* Touch Reticle Coordinates on Cursor */
.hud-reticle-box {
  position: absolute;
  pointer-events: none;
  z-index: 5;
  width: 32px;
  height: 32px;
  border: 1px dashed rgba(0, 240, 255, 0.45);
  border-radius: 50%;
  transform: translate(-50%, -50%);
  display: none;
  transition: opacity 0.2s ease;
}

/* Responsive Overrides */
@media (max-width: 860px) {
  .hud-ui-shell {
    padding: 10px;
  }
  .hud-middle-stage {
    flex-direction: column;
    align-items: stretch;
    justify-content: flex-end;
    gap: 10px;
  }
  .hud-modes-dock,
  .hud-params-deck {
    width: 100%;
  }
  .hud-telemetry-strip {
    display: none;
  }
}