:root {
  font-family: "Segoe UI", "PingFang SC", "Microsoft YaHei", system-ui, sans-serif;
  color: #f3f2ff;
  background: #0e1022;
}

* { box-sizing: border-box; }

body {
  min-height: 100vh;
  margin: 0;
  padding: 1rem;
  background:
    radial-gradient(circle at 20% 15%, rgba(111, 102, 255, .24), transparent 26rem),
    radial-gradient(circle at 85% 70%, rgba(68, 211, 204, .12), transparent 30rem),
    #0e1022;
}

.back-link {
  display: inline-flex;
  min-height: 44px;
  align-items: center;
  color: #c9cbff;
  text-underline-offset: .2em;
}

.game-shell {
  width: min(100%, 760px);
  margin: 3rem auto;
}

header { text-align: center; }

.eyebrow {
  color: #8fe4df;
  font-size: .75rem;
  font-weight: 800;
  letter-spacing: .16em;
}

h1 {
  margin: .5rem 0;
  font-size: clamp(2rem, 8vw, 4.2rem);
  line-height: 1.08;
}

header p:last-child { color: #aeb3d5; line-height: 1.7; }

.game-panel,
.how-to {
  margin-top: 2rem;
  padding: clamp(1rem, 4vw, 2rem);
  background: rgba(27, 31, 66, .78);
  border: 1px solid rgba(149, 151, 255, .32);
  border-radius: 24px;
  box-shadow: 0 24px 80px rgba(0, 0, 0, .3);
}

.score-row {
  display: flex;
  justify-content: space-between;
  color: #bfc3e6;
}

.target {
  width: min(100%, 360px);
  aspect-ratio: 2 / 1;
  margin: 2rem auto 1rem;
  border: 2px solid rgba(255, 255, 255, .3);
  border-radius: 22px;
  background: #6f70d8;
  box-shadow: 0 0 50px currentColor;
  transition: opacity .25s ease, transform .25s ease;
}

.target.hidden {
  opacity: .08;
  transform: scale(.94);
  background: repeating-linear-gradient(45deg, #272b50 0 12px, #1d2141 12px 24px) !important;
}

.message {
  min-height: 3rem;
  text-align: center;
  color: #c6caea;
}

.choices {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: .75rem;
}

.choice {
  min-height: 100px;
  border: 2px solid rgba(255, 255, 255, .2);
  border-radius: 18px;
  cursor: pointer;
}

.choice:hover { transform: translateY(-2px); }
.choice:focus-visible,
.main-button:focus-visible,
.back-link:focus-visible { outline: 3px solid #8fe4df; outline-offset: 4px; }
.choice.correct { box-shadow: 0 0 0 4px #8fe4df; }
.choice.wrong { box-shadow: 0 0 0 4px #ff8eaa; }

.main-button {
  display: block;
  min-height: 48px;
  margin: 1.3rem auto 0;
  padding: .7rem 1.3rem;
  color: #101224;
  background: #8fe4df;
  border: 0;
  border-radius: 999px;
  font: inherit;
  font-weight: 800;
  cursor: pointer;
}

.main-button[hidden] { display: none; }

.how-to { color: #b9bddc; line-height: 1.7; }
.how-to h2 { color: #fff; }

.visually-hidden {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

@media (max-width: 560px) {
  body { padding: .75rem; }
  .game-shell { margin-top: 1.5rem; }
  .choices { grid-template-columns: repeat(2, 1fr); }
  .choice { min-height: 88px; }
}

@media (prefers-reduced-motion: reduce) {
  * { transition: none !important; }
}