:root {
  --bg: #02050b;
  --red: 255, 46, 72;
  --yellow: 255, 228, 156;
  --green: 82, 255, 154;
  --cyan: 112, 220, 255;
}

* { box-sizing: border-box; }

html, body {
  width: 100%;
  height: 100%;
  margin: 0;
  overflow: hidden;
  background: var(--bg);
  font-family: "Segoe UI", system-ui, sans-serif;
  color: rgba(240,248,255,0.92);
}

.viewport {
  position: relative;
  width: 100vw;
  height: 100svh;
  display: grid;
  place-items: center;
  overflow: hidden;
  background:
    radial-gradient(circle at center, rgba(28,86,130,0.16), transparent 48%),
    linear-gradient(180deg, #030710 0%, #02050b 100%);
}

.stage {
  position: relative;
  width: min(100vw, calc(100svh * 1024 / 1792));
  height: min(100svh, calc(100vw * 1792 / 1024));
  aspect-ratio: 1024 / 1792;
  overflow: hidden;
  background: #040a14;
  box-shadow:
    0 0 0 1px rgba(160,220,255,0.10),
    0 0 60px rgba(20,80,150,0.22);
}

.bg {
  position: absolute;
  inset: 0;
  z-index: 0;
  background:
    linear-gradient(rgba(0, 8, 18, 0.03), rgba(0, 4, 12, 0.10)),
    url("./assets/city-road-user-bg.png") center / cover no-repeat;
  filter: saturate(1.03) contrast(1.06) brightness(0.98);
  transform: scale(1.002);
}

.traffic {
  position: absolute;
  inset: 0;
  z-index: 3;
  pointer-events: none;
  mix-blend-mode: screen;
}

.lane-band {
  position: absolute;
  top: 0;
  height: 100%;
  overflow: hidden;
  pointer-events: none;
}

.lane-band.left {
  left: 46.2%;
  width: 4.3%;
}

.lane-band.right {
  left: 51.2%;
  width: 4.3%;
}

.lane-band::before {
  content: "";
  position: absolute;
  inset: 0;
  opacity: 0.08;
  filter: blur(5px);
}

.lane-band.left::before {
  background: linear-gradient(90deg, transparent, rgba(var(--red), 0.72), transparent);
}

.lane-band.right::before {
  background: linear-gradient(90deg, transparent, rgba(var(--yellow), 0.56), transparent);
}

.sub-lane {
  position: absolute;
  top: 0;
  height: 100%;
  width: 32%;
  overflow: hidden;
}

.left .sub-lane.a { left: 8%; }
.left .sub-lane.b { left: 58%; }

.right .sub-lane.a { left: 10%; }
.right .sub-lane.b { left: 60%; }

.car-light {
  position: absolute;
  left: 50%;
  width: var(--w);
  height: var(--h);
  top: 0;
  border-radius: 999px;
  opacity: var(--opacity);
  transform: translate(-50%, -50%);
  will-change: top, opacity, transform;
}

.car-light.red {
  background: linear-gradient(
    180deg,
    transparent,
    rgba(var(--red), 0.12),
    rgba(var(--red), 1),
    rgba(var(--red), 0.42),
    transparent
  );
  box-shadow:
    0 0 8px rgba(var(--red), 0.98),
    0 0 18px rgba(var(--red), 0.40);
}

.car-light.yellow {
  background: linear-gradient(
    180deg,
    transparent,
    rgba(var(--yellow), 0.10),
    rgba(var(--yellow), 0.94),
    rgba(var(--yellow), 0.30),
    transparent
  );
  box-shadow:
    0 0 8px rgba(var(--yellow), 0.82),
    0 0 16px rgba(var(--yellow), 0.28);
}

.car-light.waiting {
  transform: translate(-50%, -50%) scale(0.88);
  opacity: calc(var(--opacity) * 0.70);
}

.stop-line {
  position: absolute;
  z-index: 4;
  height: 1px;
  opacity: 0;
  pointer-events: none;
  background: rgba(255,255,255,0.70);
  box-shadow: 0 0 10px rgba(255,255,255,0.35);
}

.stop-line.left {
  left: 45.5%;
  top: 51.8%;
  width: 6.0%;
}

.stop-line.right {
  left: 50.6%;
  top: 45%;
  width: 6.0%;
}

.stage[data-signal="red"] .stop-line {
  opacity: 0.36;
}

.signal-panel {
  position: absolute;
  right: clamp(10px, 2.2vw, 24px);
  top: clamp(10px, 2.2vh, 24px);
  z-index: 9;
  display: grid;
  gap: 0.5rem;
  min-width: 140px;
  padding: 0.7rem 0.8rem;
  border: 1px solid rgba(var(--cyan), 0.22);
  border-radius: 12px;
  background: rgba(2, 8, 16, 0.54);
  backdrop-filter: blur(8px);
  box-shadow:
    0 0 18px rgba(var(--cyan), 0.14),
    inset 0 0 18px rgba(255,255,255,0.03);
  pointer-events: none;
}

.signal-title {
  font-size: 0.62rem;
  letter-spacing: 0.14em;
  color: rgba(var(--cyan), 0.78);
}

.signal-lamps {
  display: flex;
  gap: 0.5rem;
  align-items: center;
}

.lamp {
  width: 18px;
  aspect-ratio: 1;
  border-radius: 50%;
  opacity: 0.22;
  background: rgba(180, 200, 220, 0.34);
  box-shadow: inset 0 0 8px rgba(0,0,0,0.82);
  transition: opacity 0.25s ease, box-shadow 0.25s ease, background 0.25s ease, transform 0.25s ease;
}

.lamp.green { background: rgba(var(--green), 0.45); }
.lamp.yellow { background: rgba(var(--yellow), 0.45); }
.lamp.red { background: rgba(var(--red), 0.45); }

.stage[data-signal="green"] .lamp.green,
.stage[data-signal="yellow"] .lamp.yellow,
.stage[data-signal="red"] .lamp.red {
  opacity: 1;
  transform: scale(1.12);
}

.stage[data-signal="green"] .lamp.green {
  box-shadow: 0 0 12px rgba(var(--green), 0.92), 0 0 26px rgba(var(--green), 0.42);
}

.stage[data-signal="yellow"] .lamp.yellow {
  box-shadow: 0 0 12px rgba(var(--yellow), 0.96), 0 0 26px rgba(var(--yellow), 0.42);
}

.stage[data-signal="red"] .lamp.red {
  box-shadow: 0 0 12px rgba(var(--red), 0.96), 0 0 26px rgba(var(--red), 0.42);
}

.signal-status {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  gap: 1rem;
  font-size: 0.66rem;
  letter-spacing: 0.10em;
  color: rgba(235,248,255,0.78);
}

.signal-count {
  color: rgba(var(--cyan), 0.84);
  font-variant-numeric: tabular-nums;
}

.signal-progress {
  position: relative;
  height: 3px;
  overflow: hidden;
  border-radius: 999px;
  background: rgba(255,255,255,0.10);
}

.signal-progress span {
  position: absolute;
  inset: 0 auto 0 0;
  width: var(--progress, 0%);
  border-radius: inherit;
  background: rgba(var(--cyan), 0.70);
  box-shadow: 0 0 12px rgba(var(--cyan), 0.38);
  transition: width 0.14s linear, background 0.25s ease;
}

.stage[data-signal="green"] .signal-progress span { background: rgba(var(--green), 0.75); }
.stage[data-signal="yellow"] .signal-progress span { background: rgba(var(--yellow), 0.75); }
.stage[data-signal="red"] .signal-progress span { background: rgba(var(--red), 0.75); }

.road-signal {
  position: absolute;
  z-index: 8;
  width: 10px;
  aspect-ratio: 1;
  border-radius: 50%;
  opacity: 0.9;
  pointer-events: none;
  background: rgba(var(--green), 0.55);
  box-shadow: 0 0 10px rgba(var(--green), 0.72), 0 0 22px rgba(var(--green), 0.28);
  transition: background 0.25s ease, box-shadow 0.25s ease;
}

.road-signal.left {
  left: 44.0%;
  top: 51.8%;
}

.road-signal.right {
  right: 43.0%;
  top: 45%;
}

.stage[data-signal="yellow"] .road-signal {
  background: rgba(var(--yellow), 0.72);
  box-shadow: 0 0 10px rgba(var(--yellow), 0.80), 0 0 22px rgba(var(--yellow), 0.30);
}

.stage[data-signal="red"] .road-signal {
  background: rgba(var(--red), 0.72);
  box-shadow: 0 0 10px rgba(var(--red), 0.82), 0 0 22px rgba(var(--red), 0.34);
}

.cross-traffic {
  position: absolute;
  left: 38.5%;
  top: 47.0%;
  width: 23.0%;
  height: 3.6%;
  z-index: 4;
  pointer-events: none;
  overflow: hidden;
  opacity: 0;
  transition: opacity 0.35s ease;
  mix-blend-mode: screen;
}

.stage[data-signal="red"] .cross-traffic {
  opacity: 1;
}

.cross-traffic::before {
  content: "";
  position: absolute;
  inset: 28% 0;
  opacity: 0.10;
  background: linear-gradient(
    90deg,
    transparent,
    rgba(var(--cyan), 0.36),
    rgba(var(--yellow), 0.22),
    transparent
  );
  filter: blur(6px);
}

.x-light {
  position: absolute;
  top: var(--y);
  width: var(--w);
  height: var(--h);
  border-radius: 999px;
  opacity: 0;
  transform: translateY(-50%);
  will-change: left, right, opacity;
  animation-duration: var(--duration);
  animation-delay: var(--delay);
  animation-timing-function: linear;
  animation-iteration-count: infinite;
  animation-play-state: paused;
}

.stage[data-signal="red"] .x-light {
  animation-play-state: running;
}

.x-light.warm {
  left: -18%;
  animation-name: xMoveRight;
  background: linear-gradient(
    90deg,
    transparent,
    rgba(var(--red), 0.18),
    rgba(var(--red), 0.92),
    rgba(var(--red), 0.34),
    transparent
  );
  box-shadow:
    0 0 7px rgba(var(--red), 0.78),
    0 0 16px rgba(var(--red), 0.28);
}

.x-light.red {
  right: -18%;
  animation-name: xMoveLeft;
  background: linear-gradient(
    90deg,
    transparent,
    rgba(var(--yellow), 0.20),
    rgba(var(--yellow), 0.94),
    rgba(var(--yellow), 0.36),
    transparent
  );
  box-shadow:
    0 0 7px rgba(var(--yellow), 0.74),
    0 0 16px rgba(var(--yellow), 0.24);
}

@keyframes xMoveRight {
  0%   { left: -18%; opacity: 0; }
  14%  { opacity: var(--opacity); }
  84%  { opacity: var(--opacity); }
  100% { left: 112%; opacity: 0; }
}

@keyframes xMoveLeft {
  0%   { right: -18%; opacity: 0; }
  14%  { opacity: var(--opacity); }
  84%  { opacity: var(--opacity); }
  100% { right: 112%; opacity: 0; }
}

.ambient {
  position: absolute;
  inset: 0;
  z-index: 4;
  pointer-events: none;
  background:
    radial-gradient(circle at 50% 45%, rgba(var(--cyan), 0.06), transparent 38%),
    linear-gradient(90deg, rgba(0,0,0,0.18), transparent 16% 84%, rgba(0,0,0,0.18));
  mix-blend-mode: screen;
}

.scanlines {
  position: absolute;
  inset: 0;
  z-index: 5;
  pointer-events: none;
  opacity: 0.07;
  background: repeating-linear-gradient(
    180deg,
    rgba(255,255,255,0.10) 0 1px,
    transparent 1px 5px
  );
  animation: scan 8s linear infinite;
}

@keyframes scan {
  to { transform: translateY(40px); }
}

.vignette {
  position: absolute;
  inset: 0;
  z-index: 5;
  pointer-events: none;
  background:
    radial-gradient(circle at center, transparent 0 58%, rgba(0,0,0,0.46) 100%),
    linear-gradient(180deg, rgba(0,0,0,0.12), transparent 25% 75%, rgba(0,0,0,0.14));
}

.hud-caption {
  position: absolute;
  left: 16px;
  bottom: 16px;
  z-index: 8;
  pointer-events: none;
  text-shadow: 0 0 14px rgba(var(--cyan), 0.40);
}

.hud-caption p {
  margin: 0;
  color: rgba(var(--cyan), 0.82);
  font-size: clamp(0.62rem, 1.2vw, 0.82rem);
  letter-spacing: 0.12em;
  text-transform: uppercase;
  font-weight: 400;
}

.hud-caption h1 {
  margin: 0.32rem 0 0;
  font-size: clamp(1.2rem, 2.8vw, 1.8rem);
  font-weight: 300;
  letter-spacing: 0.18em;
  text-transform: uppercase;
}

.hud-caption h1 + p {
  font-size: clamp(0.48rem, 0.9vw, 0.68rem) !important;
  margin-top: 0.48rem !important;
  opacity: 0.75 !important;
  letter-spacing: 0.10em !important;
  text-transform: none !important;
}

@media (max-width: 480px) {
  .stage {
    width: 100vw;
    height: 100svh;
  }

  .lane-band.left {
    left: 45.8%;
    width: 4.9%;
  }

  .lane-band.right {
    left: 51.1%;
    width: 4.9%;
  }

  .hud-caption {
    left: 12px;
    bottom: 12px;
  }

  .hud-caption p {
    font-size: 0.58rem;
  }

  .hud-caption h1 {
    font-size: 1rem;
    margin-top: 0.16rem;
  }

  .signal-panel {
    right: 10px;
    top: 10px;
    min-width: 118px;
    padding: 0.55rem 0.6rem;
  }

  .lamp { width: 15px; }

  .stop-line.left {
    left: 45.0%;
    top: 51.8%;
    width: 6.6%;
  }

  .stop-line.right {
    left: 50.6%;
    width: 6.6%;
  }
}

@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: 1ms !important;
    animation-iteration-count: 1 !important;
  }
}