/* =========================================================
   CRS CANONICAL RACK UNIT
   
   Purpose: Single source of truth for rack-mounted modules
   Scope: CRS pages only (NOT Workshop Café)
   Philosophy: Infrastructure, not decoration
   
   This is the reference object. Do not drift.
   ========================================================= */

/* ------------------------------
   RACK CONTAINER
   Vertical alignment rails
   ------------------------------ */
.rack-container {
  position: relative;
  width: 100%;
  max-width: 1200px;
  margin: 0 auto;
  padding: 2rem 0;
}

/* Vertical alignment rails - subtle infrastructure cue */
.rack-container::after {
  content: '';
  position: absolute;
  top: 0;
  left: 48px;
  right: 48px;
  height: 100%;
  border-left: 1px solid rgba(255,255,255,0.05);
  border-right: 1px solid rgba(255,255,255,0.05);
  pointer-events: none;
  z-index: 0;
}

/* ------------------------------
   RACK UNIT (CANONICAL)
   The reference object
   ------------------------------ */
.rack-unit {
  /* STRUCTURE */
  position: relative;
  width: 100%;
  margin-bottom: 1.5rem;
  padding: 2rem;
  box-sizing: border-box;
  
  /* MATERIAL */
  background: linear-gradient(
    135deg,
    rgba(20, 20, 20, 0.95),
    rgba(15, 15, 15, 0.85),
    rgba(18, 18, 18, 0.95)
  );
  background-blend-mode: overlay; /* Brushed aluminum simulation */
  
  /* MOUNTING */
  border: 1px solid rgba(212, 160, 23, 0.4); /* Gold accent border */
  border-left-width: 4px; /* Device-type indicator */
  border-radius: 4px;
  
  /* DEPTH (this is critical - don't flatten) */
  box-shadow: 
    inset 0 1px 3px rgba(255, 255, 255, 0.05),  /* Top highlight - manufactured edge */
    inset 0 -1px 0 rgba(0, 0, 0, 0.3),          /* Bottom shadow - depth */
    0 4px 12px rgba(0, 0, 0, 0.4);              /* Drop shadow - mounted into chassis */
  
  /* NOISE (material texture - NOT decoration) */
  background-image: 
    url("data:image/svg+xml,%3Csvg viewBox='0 0 200 200' xmlns='http://www.w3.org/2000/svg'%3E%3Cfilter id='noise'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.9' numOctaves='4' /%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23noise)' opacity='0.04'/%3E%3C/svg%3E");
  
  /* ACCESSIBILITY */
  isolation: isolate; /* Prevent blending issues */
  z-index: 1;
}

/* ------------------------------
   DEVICE-TYPE INDICATORS
   Left border color = function
   ------------------------------ */
.rack-unit.device-rehearsal {
  border-left-color: #39FF14; /* LED Green - Live/Active */
}

.rack-unit.device-studio {
  border-left-color: #FFB627; /* LED Amber - Production */
}

.rack-unit.device-av {
  border-left-color: #FF8C00; /* LED Orange - Field Operations */
}

.rack-unit.device-cafe {
  border-left-color: #FFB627; /* LED Amber - Public Interface */
}

.rack-unit.device-community {
  border-left-color: #FF8C00; /* LED Orange - Community Access */
}

.rack-unit.device-status {
  border-left-color: #FF8C00; /* LED Orange - System Status */
}

/* ------------------------------
   RACK UNIT HEADER
   Module identification
   ------------------------------ */
.rack-unit-header {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  margin-bottom: 1.5rem;
}

/* ------------------------------
   LED STATUS INDICATORS
   Operational state signaling
   ------------------------------ */
.rack-unit-led {
  display: inline-flex;
  align-items: center;
  margin-right: 0.5rem;
}

.led {
  width: 10px;
  height: 10px;
  border-radius: 50%;
  display: inline-block;
  box-shadow: 0 0 8px currentColor;
  /* NO pulsing unless tied to real state */
}

.led.green {
  background: #39FF14;
  color: #39FF14;
}

.led.yellow,
.led.amber {
  background: #FFB627;
  color: #FFB627;
}

.led.orange {
  background: #FF8C00;
  color: #FF8C00;
}

.led.red {
  background: #C41E3A;
  color: #C41E3A;
}

/* LED pulse animation - USE SPARINGLY, ONLY FOR LIVE STATE */
@keyframes pulse-led {
  0%, 100% { opacity: 1; }
  50% { opacity: 0.4; }
}

/* Apply pulse ONLY when explicitly needed */
.led.pulse {
  animation: pulse-led 2s ease-in-out infinite;
  will-change: opacity; /* Hardware acceleration - prevent mobile stutter */
}

/* ------------------------------
   RACK UNIT TITLE
   Module label
   ------------------------------ */
.rack-unit-title {
  font-family: 'JetBrains Mono', monospace;
  font-size: 1rem;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: rgba(245, 245, 245, 0.9);
  margin: 0;
}

/* ------------------------------
   RACK UNIT CONTENT
   Module body
   ------------------------------ */
.rack-unit-content {
  font-family: 'Inter', sans-serif;
  font-size: 0.938rem;
  line-height: 1.6;
  color: rgba(245, 245, 245, 0.85);
}

/* ------------------------------
   RACK SCREWS (OPTIONAL)
   Mounting hardware visual cue
   ------------------------------ */
.rack-screw {
  position: absolute;
  width: 12px;
  height: 12px;
  background: radial-gradient(circle, #444 30%, #222 70%);
  border-radius: 50%;
  border: 1px solid rgba(0, 0, 0, 0.5);
  box-shadow: 
    inset 0 1px 2px rgba(255, 255, 255, 0.2),
    0 1px 2px rgba(0, 0, 0, 0.3);
  pointer-events: none; /* CRITICAL: Don't intercept clicks */
}

/* Screw positioning (standard rack mounting holes) */
.rack-screw:nth-of-type(1) { top: 12px; left: 12px; }
.rack-screw:nth-of-type(2) { top: 12px; right: 12px; }
.rack-screw:nth-of-type(3) { bottom: 12px; left: 12px; }
.rack-screw:nth-of-type(4) { bottom: 12px; right: 12px; }

/* Cross-head screw detail */
.rack-screw::after {
  content: '';
  position: absolute;
  top: 50%;
  left: 50%;
  width: 8px;
  height: 1px;
  background: rgba(0, 0, 0, 0.4);
  transform: translate(-50%, -50%);
}

.rack-screw::before {
  content: '';
  position: absolute;
  top: 50%;
  left: 50%;
  width: 1px;
  height: 8px;
  background: rgba(0, 0, 0, 0.4);
  transform: translate(-50%, -50%);
}

/* ------------------------------
   ACCESSIBILITY
   ------------------------------ */

/* Reduced motion safety - NO animations for users who prefer less motion */
@media (prefers-reduced-motion: reduce) {
  .led,
  .rack-unit,
  .rack-screw {
    animation: none !important;
    transition: none !important;
  }
}

/* Ensure adequate contrast for labels */
.rack-unit-title {
  color: #e0e0e0; /* WCAG AA compliant on dark background */
}

/* ------------------------------
   MOBILE RESPONSIVE
   ------------------------------ */
@media (max-width: 767px) {
  .rack-unit {
    padding: 1.5rem 1.25rem;
  }
  
  .rack-container::after {
    left: 24px;
    right: 24px;
  }
  
  .rack-screw {
    width: 10px;
    height: 10px;
  }
}

/* ------------------------------
   USAGE RULES (CRITICAL)
   ------------------------------ */

/* 
  ✅ USE ON:
  - CRS Studio pages
  - CRS AV Services pages
  - CRS technical infrastructure pages
  - Brewforce CTAs (when appropriate)
  
  ❌ DO NOT USE ON:
  - Workshop Café pages (use flat cards instead)
  - General content pages
  - Public-facing marketing pages
  
  REASONING:
  Rack UI = institutional engineering
  Café UI = civic warmth
  Keep these separate.
*/

/* ------------------------------
   CUSTOMIZATION NOTES
   ------------------------------ */

/*
  If you need to adjust:
  
  1. DEPTH: Modify box-shadow values, not colors
  2. MATERIAL: Adjust background gradient stops, not blend mode
  3. BORDER: Change device-type colors, not structure
  4. LED: Only add .pulse class for LIVE state
  
  DO NOT:
  - Add transitions longer than 250ms
  - Add glow effects
  - Add bounce animations
  - Flatten the shadow (it's load-bearing)
  
  This is infrastructure, not decoration.
*/