*, *::before, *::after {
  box-sizing: border-box;
}

html, body {
  width: 100%;
  height: 100%;
  margin: 0;
  padding: 0;
  overflow: hidden;
  background: transparent !important;
}

:root {
  /* Neon accents */
  --neon-bracket: #b6ff1a;
  --neon-beam: #9dffcf;
  --neon-beam-core: #ffffff;

  /* HUD steel / graphite / dim green */
  --hud-steel: #7b8789;
  --hud-dim-green: rgba(182, 255, 26, 0.42);
  --hud-graphite: #384042;
  --hud-dim: rgba(109, 119, 121, 0.55);

  /* Proportional strokes relative to source */
  --stroke: clamp(6px, 1.6vmin, 24px);
  --stroke-thin: clamp(2px, 0.7vmin, 10px);
  --frame-pad: clamp(4px, 1vmin, 14px);
  --arm-len: clamp(34px, 16vmin, 160px);

  /* Ruler tick geometry */
  --tick-thick: clamp(1px, 0.22vmin, 2.5px);
  --tick-minor-w: clamp(4px, 1vmin, 11px);
  --tick-major-w: clamp(8px, 1.9vmin, 20px);
  --tick-step: clamp(6px, 1.4vmin, 15px);
}

/* Base frame wrapper placed over the webcam */
.camera-frame {
  position: absolute;
  inset: 0;
  pointer-events: none;
  overflow: hidden;
}

/* ==========================================================================
   1. Viewfinder corner brackets (L-shapes)
   Arms ~14-18% of shorter side, slow desynchronized breathing glow (~4s)
   ========================================================================== */
.corner {
  position: absolute;
  width: var(--arm-len);
  height: var(--arm-len);
  pointer-events: none;
  filter: drop-shadow(0 0 clamp(4px, 0.9vmin, 12px) rgba(182, 255, 26, 0.65));
}

.corner-tl {
  top: var(--frame-pad);
  left: var(--frame-pad);
  border-top: var(--stroke) solid var(--neon-bracket);
  border-left: var(--stroke) solid var(--neon-bracket);
  animation: bracket-breathe 4s ease-in-out infinite 0s;
}

.corner-tr {
  top: var(--frame-pad);
  right: var(--frame-pad);
  border-top: var(--stroke) solid var(--neon-bracket);
  border-right: var(--stroke) solid var(--neon-bracket);
  animation: bracket-breathe 4s ease-in-out infinite -1.1s;
}

.corner-br {
  bottom: var(--frame-pad);
  right: var(--frame-pad);
  border-bottom: var(--stroke) solid var(--neon-bracket);
  border-right: var(--stroke) solid var(--neon-bracket);
  animation: bracket-breathe 4s ease-in-out infinite -2.2s;
}

.corner-bl {
  bottom: var(--frame-pad);
  left: var(--frame-pad);
  border-bottom: var(--stroke) solid var(--neon-bracket);
  border-left: var(--stroke) solid var(--neon-bracket);
  animation: bracket-breathe 4s ease-in-out infinite -3.3s;
}

@keyframes bracket-breathe {
  0%, 100% {
    opacity: 0.62;
    filter: drop-shadow(0 0 clamp(3px, 0.7vmin, 8px) rgba(182, 255, 26, 0.45));
  }
  50% {
    opacity: 1;
    filter: drop-shadow(0 0 clamp(6px, 1.4vmin, 18px) rgba(182, 255, 26, 0.85))
            drop-shadow(0 0 clamp(1px, 0.3vmin, 4px) var(--neon-bracket));
  }
}

/* ==========================================================================
   2. HUD ruler ticks (left, right, bottom-center)
   Small steel/graphite ticks (#6d7779), every 5th tick longer in dim green (#5f8f3a).
   No continuous solid lines.
   ========================================================================== */
.hud-ticks {
  position: absolute;
  pointer-events: none;
}

/* Left & Right: central 40% of height */
.ticks-left, .ticks-right {
  top: 30%;
  height: 40%;
  width: var(--tick-major-w);
}

.ticks-left {
  left: var(--frame-pad);
  background:
    repeating-linear-gradient(
      to bottom,
      var(--hud-dim-green) 0px,
      var(--hud-dim-green) var(--tick-thick),
      transparent var(--tick-thick),
      transparent calc(var(--tick-step) * 5)
    ) left / var(--tick-major-w) 100% no-repeat,
    repeating-linear-gradient(
      to bottom,
      var(--hud-steel) 0px,
      var(--hud-steel) var(--tick-thick),
      transparent var(--tick-thick),
      transparent var(--tick-step)
    ) left / var(--tick-minor-w) 100% no-repeat;
}

.ticks-right {
  right: var(--frame-pad);
  background:
    repeating-linear-gradient(
      to bottom,
      var(--hud-dim-green) 0px,
      var(--hud-dim-green) var(--tick-thick),
      transparent var(--tick-thick),
      transparent calc(var(--tick-step) * 5)
    ) right / var(--tick-major-w) 100% no-repeat,
    repeating-linear-gradient(
      to bottom,
      var(--hud-steel) 0px,
      var(--hud-steel) var(--tick-thick),
      transparent var(--tick-thick),
      transparent var(--tick-step)
    ) right / var(--tick-minor-w) 100% no-repeat;
}

/* Bottom center: short segment */
.ticks-bottom {
  bottom: var(--frame-pad);
  left: 50%;
  transform: translateX(-50%);
  width: calc(var(--tick-step) * 20);
  max-width: 45vw;
  height: var(--tick-major-w);
  background:
    repeating-linear-gradient(
      to right,
      var(--hud-dim-green) 0px,
      var(--hud-dim-green) var(--tick-thick),
      transparent var(--tick-thick),
      transparent calc(var(--tick-step) * 5)
    ) bottom / 100% var(--tick-major-w) no-repeat,
    repeating-linear-gradient(
      to right,
      var(--hud-steel) 0px,
      var(--hud-steel) var(--tick-thick),
      transparent var(--tick-thick),
      transparent var(--tick-step)
    ) bottom / 100% var(--tick-minor-w) no-repeat;
}

/* ==========================================================================
   3. Traveling perimeter light beam
   Thin ring (~half bracket stroke), conic gradient with @property --beam-angle,
   sweeps once in ~4s, then hidden for ~7s (cycle 11s).
   Segment in soft neon/mint (#9dffcf).
   ========================================================================== */
@property --beam-angle {
  syntax: "<angle>";
  inherits: false;
  initial-value: 0deg;
}

.beam-ring {
  position: absolute;
  inset: var(--frame-pad);
  border: var(--stroke-thin) solid transparent;
  pointer-events: none;
  background: conic-gradient(
    from var(--beam-angle) at 50% 50%,
    transparent 0deg,
    transparent 14deg,
    rgba(157, 255, 207, 0.05) 20deg,
    rgba(157, 255, 207, 0.45) 26deg,
    var(--neon-beam) 32deg,
    var(--neon-beam-core) 35deg,
    var(--neon-beam) 38deg,
    rgba(157, 255, 207, 0.45) 44deg,
    rgba(157, 255, 207, 0.05) 50deg,
    transparent 56deg,
    transparent 360deg
  ) border-box;
  -webkit-mask:
    linear-gradient(#fff 0 0) padding-box,
    linear-gradient(#fff 0 0) border-box;
  -webkit-mask-composite: xor;
  mask:
    linear-gradient(#fff 0 0) padding-box,
    linear-gradient(#fff 0 0) border-box;
  mask-composite: exclude;
  filter: drop-shadow(0 0 clamp(3px, 0.7vmin, 9px) rgba(157, 255, 207, 0.8));
  animation: beam-sweep 11s linear infinite;
}

@keyframes beam-sweep {
  0% {
    --beam-angle: 0deg;
    opacity: 0;
  }
  2% {
    opacity: 1;
  }
  34% {
    opacity: 1;
  }
  36.36% {
    --beam-angle: 360deg;
    opacity: 0;
  }
  100% {
    --beam-angle: 360deg;
    opacity: 0;
  }
}

/* ==========================================================================
   4. Sober HUD accents
   Small steel/graphite dots and chamfer cues; center stays clear.
   ========================================================================== */
.hud-accent {
  position: absolute;
  pointer-events: none;
}

/* Top-left subtle graphite dots */
.accent-tl {
  top: calc(var(--frame-pad) + var(--stroke) + clamp(6px, 1.2vmin, 14px));
  left: calc(var(--frame-pad) + var(--stroke) + clamp(6px, 1.2vmin, 14px));
  width: clamp(16px, 3.5vmin, 32px);
  height: clamp(3px, 0.6vmin, 6px);
  background:
    radial-gradient(circle, var(--hud-steel) 40%, transparent 45%) 0 50% / clamp(3px, 0.6vmin, 6px) clamp(3px, 0.6vmin, 6px) no-repeat,
    radial-gradient(circle, var(--hud-steel) 40%, transparent 45%) 50% 50% / clamp(3px, 0.6vmin, 6px) clamp(3px, 0.6vmin, 6px) no-repeat,
    radial-gradient(circle, var(--hud-dim) 40%, transparent 45%) 100% 50% / clamp(3px, 0.6vmin, 6px) clamp(3px, 0.6vmin, 6px) no-repeat;
}

/* Bottom-right small steel chamfer tick */
.accent-br {
  bottom: calc(var(--frame-pad) + var(--stroke) + clamp(6px, 1.2vmin, 14px));
  right: calc(var(--frame-pad) + var(--stroke) + clamp(6px, 1.2vmin, 14px));
  width: clamp(8px, 1.8vmin, 18px);
  height: clamp(8px, 1.8vmin, 18px);
  border-bottom: var(--tick-thick) solid var(--hud-steel);
  border-right: var(--tick-thick) solid var(--hud-steel);
  opacity: 0.7;
}

/* ==========================================================================
   Accessibility & Reduced Motion
   ========================================================================== */
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation: none !important;
  }
  .corner {
    opacity: 0.88;
    filter: drop-shadow(0 0 clamp(4px, 1vmin, 12px) rgba(182, 255, 26, 0.6));
  }
  .beam-ring {
    display: none !important;
  }
}