:root {
  --page-bg: linear-gradient(180deg, #08111f 0%, #12253f 55%, #1a355a 100%);
  --panel-bg: rgba(8, 17, 31, 0.82);
  --panel-border: rgba(166, 214, 255, 0.28);
  --text-main: #f1f7ff;
  --text-muted: #b8cae0;
  --player-color: #5df2c7;
  --bullet-color: #ffe17a;
  --enemy-color: #ff6b6b;
  --overlay-bg: rgba(5, 8, 15, 0.75);
  --button-bg: #ffe17a;
  --button-text: #18243a;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  min-height: 100vh;
  display: grid;
  place-items: center;
  font-family: "Trebuchet MS", "Hiragino Sans", sans-serif;
  background: var(--page-bg);
  color: var(--text-main);
}

.page {
  width: min(100%, 420px);
  padding: 24px 20px 32px;
}

.hud {
  margin-bottom: 16px;
  padding: 16px 18px;
  border: 1px solid var(--panel-border);
  border-radius: 18px;
  background: var(--panel-bg);
  box-shadow: 0 20px 45px rgba(0, 0, 0, 0.28);
}

.title,
.scoreboard,
.guide,
.overlay-title,
.overlay-score {
  margin: 0;
}

.title {
  font-size: 1.6rem;
  letter-spacing: 0.08em;
}

.scoreboard {
  margin-top: 8px;
  color: var(--text-muted);
  font-size: 1rem;
  display: flex;
  align-items: center;
  gap: 8px;
  flex-wrap: wrap;
}

.sep {
  opacity: 0.6;
}

.game-shell {
  position: relative;
  padding: 14px;
  border: 1px solid var(--panel-border);
  border-radius: 22px;
  background: var(--panel-bg);
  box-shadow: 0 20px 45px rgba(0, 0, 0, 0.28);
}

.game-area {
  position: relative;
  width: 300px;
  height: 500px;
  overflow: hidden;
  border-radius: 16px;
  background:
    radial-gradient(circle at top, rgba(120, 180, 255, 0.18), transparent 32%),
    linear-gradient(180deg, #112544 0%, #0a1730 65%, #060d1c 100%);
}

.game-area::before {
  content: "";
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(rgba(255, 255, 255, 0.04) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255, 255, 255, 0.04) 1px, transparent 1px);
  background-size: 30px 30px;
  pointer-events: none;
}

.entity {
  position: absolute;
  border-radius: 6px;
}

.player {
  background: var(--player-color);
  box-shadow: 0 0 12px rgba(93, 242, 199, 0.7);
}

.bullet {
  background: var(--bullet-color);
  border-radius: 999px;
  box-shadow: 0 0 10px rgba(255, 225, 122, 0.8);
}

.enemy {
  background: var(--enemy-color);
  box-shadow: 0 0 12px rgba(255, 107, 107, 0.5);
}

.powerup {
  background: linear-gradient(135deg, #8af7ff 0%, #5df2c7 100%);
  border-radius: 999px;
  box-shadow: 0 0 12px rgba(138, 247, 255, 0.9);
}

.effect {
  position: absolute;
  border-radius: 999px;
  pointer-events: none;
}

.effect-enemy {
  border: 2px solid rgba(255, 225, 122, 0.95);
  box-shadow: 0 0 18px rgba(255, 225, 122, 0.7);
}

.effect-player {
  border: 3px solid rgba(255, 107, 107, 0.95);
  box-shadow: 0 0 22px rgba(255, 107, 107, 0.8);
}

.effect-powerup {
  border: 2px solid rgba(138, 247, 255, 0.95);
  box-shadow: 0 0 20px rgba(138, 247, 255, 0.9);
}

.game-area.hit-flash {
  animation: hitFlash 240ms ease-out;
}

@keyframes hitFlash {
  0% {
    filter: brightness(1);
  }
  40% {
    filter: brightness(2.1);
  }
  100% {
    filter: brightness(1);
  }
}

.overlay {
  position: absolute;
  inset: 14px;
  display: grid;
  place-items: center;
  border-radius: 16px;
  background: var(--overlay-bg);
}

.hidden {
  display: none;
}

.overlay-card {
  width: min(100%, 220px);
  padding: 24px 20px;
  text-align: center;
  border-radius: 18px;
  background: rgba(12, 20, 36, 0.96);
  border: 1px solid rgba(255, 255, 255, 0.12);
}

.overlay-title {
  font-size: 1.5rem;
  letter-spacing: 0.08em;
}

.overlay-score {
  margin-top: 12px;
  color: var(--text-muted);
}

.restart-button {
  margin-top: 18px;
  width: 100%;
  padding: 12px 16px;
  border: 0;
  border-radius: 999px;
  font: inherit;
  font-weight: 700;
  letter-spacing: 0.06em;
  color: var(--button-text);
  background: var(--button-bg);
  cursor: pointer;
}

.guide {
  margin-top: 14px;
  text-align: center;
  color: var(--text-muted);
  font-size: 0.95rem;
}

@media (max-width: 380px) {
  .page {
    padding-inline: 12px;
  }

  .game-shell {
    padding: 10px;
  }

  .overlay {
    inset: 10px;
  }
}