:root {
  color-scheme: dark;
  font-family: "Segoe UI", "Microsoft YaHei", sans-serif;
  background: #050914;
  color: #dff8ff;
}

* {
  box-sizing: border-box;
}

html,
body {
  width: 100%;
  height: 100%;
  margin: 0;
  overflow: hidden;
}

body {
  display: grid;
  place-items: center;
  background:
    radial-gradient(circle at 31% 52%, rgba(21, 144, 190, 0.2), transparent 30%),
    radial-gradient(circle at 69% 52%, rgba(198, 229, 236, 0.1), transparent 30%),
    #050914;
}

.game-shell {
  width: min(1120px, 100vw);
  padding: 18px;
}

.title-bar {
  display: flex;
  align-items: end;
  justify-content: space-between;
  margin-bottom: 10px;
  letter-spacing: 0.12em;
}

.title-bar h1 {
  margin: 0;
  color: #c9f7ff;
  font-size: clamp(20px, 3vw, 32px);
  text-shadow: 0 0 18px rgba(66, 207, 255, 0.7);
}

.title-bar p {
  margin: 0 0 4px;
  color: #668c9c;
  font-size: 11px;
}

.canvas-frame {
  position: relative;
  overflow: hidden;
  border: 1px solid rgba(105, 222, 255, 0.5);
  border-radius: 18px;
  background: #070d19;
  box-shadow:
    0 0 40px rgba(0, 164, 224, 0.12),
    inset 0 0 30px rgba(15, 100, 140, 0.08);
}

#gameCanvas {
  display: block;
  width: 100%;
  aspect-ratio: 16 / 9;
  cursor: crosshair;
}

.controls-hint {
  position: absolute;
  right: 14px;
  bottom: 10px;
  color: rgba(180, 226, 240, 0.55);
  font-size: 12px;
  letter-spacing: 0.08em;
  pointer-events: none;
}

@media (max-width: 600px) {
  .game-shell {
    padding: 8px;
  }

  .title-bar p {
    display: none;
  }
}