:root {
  --bg: #07111f;
  --panel: #0d1b2f;
  --line: rgba(142, 166, 205, 0.28);
  --text: #f8fbff;
  --muted: #a8b6cc;
  --primary: #5aa7ff;
  --accent: #7ee0c3;
  --danger: #ff6b6b;
}

* {
  box-sizing: border-box;
}

body {
  min-height: 100vh;
  margin: 0;
  color: var(--text);
  font-family: "Noto Sans TC", "Segoe UI", sans-serif;
  background:
    radial-gradient(circle at 20% 20%, rgba(90, 167, 255, 0.22), transparent 28%),
    radial-gradient(circle at 80% 10%, rgba(126, 224, 195, 0.18), transparent 24%),
    var(--bg);
}

button {
  font: inherit;
}

button:disabled {
  opacity: 0.46;
  cursor: not-allowed;
}

.game-shell {
  display: grid;
  min-height: 100vh;
  place-items: center;
  padding: 24px;
}

.game-panel {
  width: min(920px, 100%);
}

.game-header,
.game-help {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
}

.game-header {
  margin-bottom: 14px;
}

.back-link {
  color: var(--muted);
  text-decoration: none;
  font-weight: 800;
}

.back-link:hover {
  color: var(--text);
}

.score-board {
  display: inline-flex;
  align-items: center;
  gap: 14px;
  min-height: 42px;
  padding: 8px 14px;
  border: 1px solid var(--line);
  border-radius: 999px;
  background: rgba(13, 27, 47, 0.82);
}

.score-board div {
  display: grid;
  gap: 2px;
  min-width: 58px;
}

.score-board span {
  color: var(--muted);
  font-size: 0.78rem;
  font-weight: 800;
}

.score-board strong {
  min-width: 3ch;
  color: var(--accent);
  font-size: 1.35rem;
  text-align: right;
}

.pause-button {
  min-height: 42px;
  padding: 0 16px;
  border: 1px solid var(--line);
  border-radius: 999px;
  color: var(--text);
  background: rgba(13, 27, 47, 0.82);
  font-weight: 900;
  cursor: pointer;
}

.pause-button:not(:disabled):hover,
.pause-button:not(:disabled):focus-visible {
  border-color: rgba(126, 224, 195, 0.72);
  color: var(--accent);
}

.game-stage {
  position: relative;
  height: min(72vh, 640px);
  min-height: 520px;
  overflow: hidden;
  border: 1px solid var(--line);
  border-radius: 24px;
  background:
    linear-gradient(180deg, rgba(7, 17, 31, 0.12), rgba(7, 17, 31, 0.94)),
    #07111f;
  box-shadow: 0 28px 80px rgba(0, 0, 0, 0.36);
  outline: none;
}

.game-stage.is-paused .player,
.game-stage.is-paused .enemy,
.game-stage.is-paused .bullet {
  opacity: 0.62;
}

.stars,
.stars::before,
.stars::after {
  position: absolute;
  inset: 0;
  background-image:
    radial-gradient(circle, rgba(255, 255, 255, 0.82) 1px, transparent 1px),
    radial-gradient(circle, rgba(126, 224, 195, 0.7) 1px, transparent 1px);
  background-position: 0 0, 24px 46px;
  background-size: 96px 116px, 140px 150px;
}

.stars::before,
.stars::after {
  content: "";
  opacity: 0.58;
}

.stars::before {
  transform: translateY(-30%);
}

.stars::after {
  opacity: 0.34;
  transform: translateY(30%);
}

.player,
.enemy,
.bullet,
.powerup {
  position: absolute;
  left: 0;
  top: 0;
  will-change: transform;
}

.player {
  width: 48px;
  height: 54px;
  clip-path: polygon(50% 0, 88% 92%, 50% 72%, 12% 92%);
  background: linear-gradient(180deg, #f8fbff 0%, var(--primary) 55%, #204a8a 100%);
  filter: drop-shadow(0 0 16px rgba(90, 167, 255, 0.66));
}

.player::after {
  content: "";
  position: absolute;
  left: 18px;
  bottom: -10px;
  width: 12px;
  height: 18px;
  border-radius: 999px;
  background: linear-gradient(180deg, var(--accent), transparent);
}

.player.is-hit {
  animation: player-hit 160ms ease-in-out 6;
}

.player.is-healed {
  animation: player-healed 220ms ease-in-out 4;
}

@keyframes player-hit {
  0%, 100% {
    opacity: 1;
    filter: drop-shadow(0 0 16px rgba(90, 167, 255, 0.66));
  }

  50% {
    opacity: 0.32;
    filter: drop-shadow(0 0 22px rgba(255, 107, 107, 0.82));
  }
}

@keyframes player-healed {
  0%, 100% {
    filter: drop-shadow(0 0 16px rgba(90, 167, 255, 0.66));
  }

  50% {
    filter: drop-shadow(0 0 26px rgba(126, 224, 195, 0.92));
  }
}

.enemy {
  width: 42px;
  height: 42px;
  border-radius: 50% 50% 44% 44%;
  background: linear-gradient(180deg, #ffb199 0%, var(--danger) 100%);
  box-shadow: 0 0 20px rgba(255, 107, 107, 0.42);
}

.enemy::before,
.enemy::after {
  content: "";
  position: absolute;
  top: 16px;
  width: 20px;
  height: 8px;
  border-radius: 999px;
  background: #ffd0c7;
}

.enemy::before {
  left: -12px;
  transform: rotate(-22deg);
}

.enemy::after {
  right: -12px;
  transform: rotate(22deg);
}

.bullet {
  width: 6px;
  height: 22px;
  border-radius: 999px;
  background: linear-gradient(180deg, #ffffff, var(--accent));
  box-shadow: 0 0 14px rgba(126, 224, 195, 0.86);
}

.powerup {
  width: 30px;
  height: 30px;
  border: 2px solid rgba(255, 255, 255, 0.82);
  border-radius: 50%;
  background: radial-gradient(circle, #ffffff 0 18%, var(--accent) 24% 58%, rgba(126, 224, 195, 0.2) 64%);
  box-shadow: 0 0 22px rgba(126, 224, 195, 0.76);
}

.powerup::after {
  content: "+";
  position: absolute;
  inset: 0;
  display: grid;
  place-items: center;
  color: #07111f;
  font-size: 1.2rem;
  font-weight: 900;
}

.burst {
  position: absolute;
  left: 0;
  top: 0;
  width: 42px;
  height: 42px;
  border: 2px solid rgba(126, 224, 195, 0.8);
  border-radius: 50%;
  background: radial-gradient(circle, rgba(255, 255, 255, 0.86) 0 18%, rgba(126, 224, 195, 0.34) 22% 48%, transparent 52%);
  pointer-events: none;
  animation: burst-out 260ms ease-out forwards;
}

@keyframes burst-out {
  from {
    opacity: 1;
    transform: translate(var(--x), var(--y)) scale(0.45);
  }

  to {
    opacity: 0;
    transform: translate(var(--x), var(--y)) scale(1.75);
  }
}

.message {
  position: absolute;
  inset: 0;
  z-index: 5;
  display: grid;
  place-content: center;
  gap: 14px;
  padding: 24px;
  text-align: center;
  background: rgba(7, 17, 31, 0.62);
}

.message.is-hidden {
  display: none;
}

.message h1 {
  margin: 0;
  font-size: clamp(2.4rem, 8vw, 4.6rem);
  line-height: 1;
}

.message p {
  margin: 0;
  color: var(--muted);
  line-height: 1.7;
}

.message button {
  justify-self: center;
  min-height: 48px;
  padding: 0 22px;
  border: 0;
  border-radius: 999px;
  color: #07111f;
  background: var(--accent);
  font-weight: 900;
  cursor: pointer;
}

.message button:hover,
.message button:focus-visible {
  background: #9bf2dc;
}

.game-help {
  flex-wrap: wrap;
  margin-top: 14px;
  color: var(--muted);
  font-size: 0.95rem;
  font-weight: 750;
}

.touch-controls {
  display: grid;
  grid-template-columns: 1fr 1.35fr 1fr;
  gap: 10px;
  margin-top: 14px;
}

.touch-controls button {
  min-height: 54px;
  border: 1px solid var(--line);
  border-radius: 18px;
  color: var(--text);
  background: rgba(13, 27, 47, 0.86);
  font-size: 1.25rem;
  font-weight: 900;
  cursor: pointer;
  touch-action: manipulation;
}

.touch-controls button:active,
.touch-controls button.is-pressed {
  border-color: rgba(126, 224, 195, 0.72);
  background: rgba(90, 167, 255, 0.28);
}

.touch-controls .shoot-button {
  color: #07111f;
  background: var(--accent);
}

.touch-controls .shoot-button:active,
.touch-controls .shoot-button.is-pressed {
  background: #9bf2dc;
}

@media (max-width: 640px) {
  .game-shell {
    padding: 14px;
  }

  .game-header,
  .game-help {
    align-items: flex-start;
    flex-direction: column;
  }

  .pause-button {
    width: 100%;
    border-radius: 18px;
  }

  .score-board {
    width: 100%;
    justify-content: space-between;
    border-radius: 18px;
  }

  .game-stage {
    min-height: 500px;
    height: 70vh;
    border-radius: 18px;
  }

  .touch-controls {
    position: sticky;
    bottom: 10px;
  }
}