:root {
  --bg: #08111f;
  --bg2: #13233c;
  --panel: rgba(8, 17, 31, 0.72);
  --line: rgba(255, 255, 255, 0.12);
  --text: #eef6ff;
  --muted: #9db3cc;
  --accent: #54d2ff;
  --accent-2: #7bffb6;
  --danger: #ff6b81;
  --track-w: min(92vw, 520px);
  --track-h: min(78vh, 760px);
  --lane-width: calc(var(--track-w) / 3);
  --player-size: clamp(52px, 10vw, 74px);
  --obstacle-base: clamp(44px, 8vw, 72px);
  color-scheme: dark;
}

* {
  box-sizing: border-box;
}

html,
body {
  margin: 0;
  min-height: 100%;
  font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  background:
    radial-gradient(circle at top, rgba(84, 210, 255, 0.18), transparent 35%),
    linear-gradient(180deg, var(--bg2), var(--bg));
  color: var(--text);
}

body {
  display: grid;
  place-items: center;
  padding: 16px;
}

button {
  font: inherit;
}

.app-shell {
  width: 100%;
  max-width: 900px;
  display: grid;
  gap: 14px;
}

.hud {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 10px;
}

.hud__item {
  background: rgba(255, 255, 255, 0.06);
  border: 1px solid var(--line);
  border-radius: 16px;
  padding: 12px 14px;
  backdrop-filter: blur(14px);
}

.hud__label {
  display: block;
  font-size: 0.8rem;
  color: var(--muted);
  margin-bottom: 4px;
}

.game-shell {
  display: grid;
  gap: 14px;
}

.game {
  position: relative;
  width: var(--track-w);
  height: var(--track-h);
  margin: 0 auto;
  overflow: hidden;
  border-radius: 28px;
  border: 1px solid var(--line);
  background: linear-gradient(180deg, #15385a 0%, #0f2135 33%, #0b1625 100%);
  box-shadow: 0 30px 80px rgba(0, 0, 0, 0.35);
}

.sky {
  position: absolute;
  inset: 0;
  background:
    radial-gradient(circle at 25% 18%, rgba(123, 255, 182, 0.24), transparent 20%),
    radial-gradient(circle at 80% 12%, rgba(84, 210, 255, 0.20), transparent 22%);
}

.track {
  position: absolute;
  inset-inline: 0;
  bottom: 0;
  height: 72%;
  background:
    linear-gradient(180deg, rgba(255,255,255,0.03), rgba(255,255,255,0.01)),
    linear-gradient(180deg, #131d2d, #0d1421);
}

.track::before,
.track::after {
  content: "";
  position: absolute;
  top: 0;
  bottom: 0;
  width: 2px;
  background: linear-gradient(180deg, transparent, rgba(255,255,255,0.18), transparent);
}

.track::before {
  left: calc(100% / 3);
}

.track::after {
  left: calc(200% / 3);
}

.lane-markers {
  position: absolute;
  inset-inline: 0;
  bottom: 0;
  height: 72%;
  pointer-events: none;
}

.lane-markers span {
  position: absolute;
  width: 4px;
  height: 100%;
  top: 0;
  background: repeating-linear-gradient(
    180deg,
    transparent 0 12px,
    rgba(255,255,255,0.16) 12px 30px,
    transparent 30px 46px
  );
  filter: blur(0.2px);
}

.lane-markers span:nth-child(1) {
  left: calc(100% / 3 - 2px);
}

.lane-markers span:nth-child(2) {
  left: calc(200% / 3 - 2px);
}

.player,
.obstacle {
  position: absolute;
  will-change: transform, width, height;
}

.player {
  left: 50%;
  bottom: 8%;
  width: var(--player-size);
  height: calc(var(--player-size) * 1.15);
  transform: translateX(-50%);
  z-index: 10;
}

.player__body {
  position: absolute;
  inset: 0;
  border-radius: 18px 18px 14px 14px;
  background:
    linear-gradient(180deg, #7bffb6 0%, #40e0d0 40%, #2f88ff 100%);
  box-shadow: 0 10px 24px rgba(84, 210, 255, 0.28);
}

.player::before {
  content: "";
  position: absolute;
  width: 44%;
  height: 34%;
  top: -12%;
  left: 28%;
  border-radius: 999px;
  background: linear-gradient(180deg, #e9fff5, #bdf3ff);
}

.player__shadow {
  position: absolute;
  width: 90%;
  height: 14%;
  left: 5%;
  bottom: -8px;
  border-radius: 999px;
  background: rgba(0, 0, 0, 0.32);
  filter: blur(6px);
}

.player.is-sliding .player__body {
  border-radius: 14px;
}

.obstacles-layer {
  position: absolute;
  inset: 0;
}

.obstacle {
  bottom: 8%;
  width: var(--obstacle-base);
  border-radius: 16px;
}

.obstacle--jump {
  height: calc(var(--obstacle-base) * 0.85);
  background: linear-gradient(180deg, #ffb86b, #ff6b81);
  box-shadow: 0 10px 24px rgba(255, 107, 129, 0.28);
}

.obstacle--slide {
  height: calc(var(--obstacle-base) * 0.55);
  background: linear-gradient(180deg, #c7f36b, #59dc78);
  box-shadow: 0 10px 24px rgba(89, 220, 120, 0.24);
}

.obstacle--lane {
  height: calc(var(--obstacle-base) * 1.15);
  background: linear-gradient(180deg, #88a4ff, #5b65ff);
  box-shadow: 0 10px 24px rgba(91, 101, 255, 0.24);
}

.overlay {
  position: absolute;
  inset: 0;
  display: none;
  place-items: center;
  padding: 24px;
  background: rgba(5, 12, 21, 0.42);
  backdrop-filter: blur(8px);
  z-index: 50;
}

.overlay--visible {
  display: grid;
}

.panel {
  width: min(100%, 420px);
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: 24px;
  padding: 22px;
  text-align: center;
}

.panel h1 {
  margin: 0 0 10px;
  font-size: clamp(1.4rem, 4vw, 2rem);
}

.panel p {
  margin: 0;
  color: var(--muted);
  line-height: 1.5;
}

.panel__actions {
  margin-top: 18px;
  display: flex;
  justify-content: center;
  gap: 10px;
  flex-wrap: wrap;
}

.btn,
.control-btn {
  border: 1px solid var(--line);
  border-radius: 14px;
  padding: 12px 16px;
  color: var(--text);
  background: rgba(255, 255, 255, 0.08);
  cursor: pointer;
  transition: transform 120ms ease, background 120ms ease;
}

.btn:hover,
.control-btn:hover,
.btn:active,
.control-btn:active {
  transform: translateY(-1px);
  background: rgba(255, 255, 255, 0.12);
}

.btn--primary {
  background: linear-gradient(180deg, rgba(84, 210, 255, 0.3), rgba(84, 210, 255, 0.14));
  border-color: rgba(84, 210, 255, 0.5);
}

.controls {
  width: var(--track-w);
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 10px;
  margin: 0 auto;
}

.control-btn {
  min-height: 56px;
  font-size: 1.2rem;
  user-select: none;
  -webkit-tap-highlight-color: transparent;
}

@media (max-width: 640px) {
  :root {
    --track-h: min(72vh, 620px);
  }

  .hud {
    grid-template-columns: repeat(2, 1fr);
  }

  .hud__item {
    padding: 10px 12px;
  }
}