:root {
  color-scheme: dark;
}

* {
  box-sizing: border-box;
  touch-action: manipulation;
}

html, body {
  margin: 0;
  padding: 0;
  height: 100dvh;
  overflow: hidden;
  background: #0a0a0a;
  color: #f5f5f5;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Apple SD Gothic Neo", "Noto Sans KR", sans-serif;
  -webkit-font-smoothing: antialiased;
  -webkit-tap-highlight-color: transparent;
  user-select: none;
  -webkit-user-select: none;
  overscroll-behavior: none;
}

main {
  height: 100%;
  max-width: 480px;
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  padding:
    max(60px, env(safe-area-inset-top))
    16px
    max(20px, env(safe-area-inset-bottom));
  gap: 16px;
}

/* 점수바: SCORE | BEST | New 버튼 */
.score-bar {
  display: flex;
  gap: 8px;
  align-items: stretch;
}

.score-box {
  flex: 1;
  background: #161616;
  border: 1px solid #2a2a2a;
  border-radius: 12px;
  padding: 8px 12px;
  text-align: center;
  min-width: 0;
}

.score-label {
  display: block;
  font-size: 11px;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: #a0a0a0;
}

.score-val,
.best-val {
  display: block;
  font-size: 22px;
  font-weight: 800;
  font-variant-numeric: tabular-nums;
  letter-spacing: -0.02em;
  color: #f5f5f5;
  margin-top: 2px;
  line-height: 1.1;
}

.new-btn {
  flex: 0 0 auto;
  font: inherit;
  color: #fff;
  background: #4f9eff;
  border: none;
  border-radius: 12px;
  padding: 0 18px;
  min-height: 56px;
  cursor: pointer;
  font-weight: 700;
  font-size: 14px;
  -webkit-tap-highlight-color: transparent;
}

.new-btn:active { background: #3d8ae8; }

/* 게임 영역 — 보드/캠버스/그리드 등을 여기에 */
#game {
  flex: 1;
  display: flex;
  align-items: center;
  justify-content: center;
}

/* 좌상단 ← 홈, 우상단 🏆 명예의 전당 — 모든 게임 공통 chrome */
.home-link,
.hof-link {
  position: fixed;
  top: max(12px, env(safe-area-inset-top));
  z-index: 10;
  width: 40px;
  height: 40px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  border-radius: 999px;
  background: rgba(0, 0, 0, 0.35);
  color: #fff;
  text-decoration: none;
  font-size: 20px;
  font-weight: 600;
  line-height: 1;
  -webkit-tap-highlight-color: transparent;
  touch-action: manipulation;
  backdrop-filter: blur(4px);
  -webkit-backdrop-filter: blur(4px);
  transition: background 0.15s ease;
  border: none;
  cursor: pointer;
  font-family: inherit;
}

.home-link { left:  max(12px, env(safe-area-inset-left)); }
.hof-link  { right: max(12px, env(safe-area-inset-right)); }

@media (hover: hover) {
  .home-link:hover,
  .hof-link:hover {
    background: rgba(0, 0, 0, 0.55);
  }
}

/* 오버레이 (게임 종료 / 완료 시 점수 + 저장 버튼) */
.overlay {
  position: fixed;
  inset: 0;
  background: rgba(0, 0, 0, 0.55);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 20;
  padding: 20px;
  backdrop-filter: blur(2px);
  -webkit-backdrop-filter: blur(2px);
}

.overlay[hidden] { display: none; }

.overlay-card {
  background: #161616;
  border: 1px solid #2a2a2a;
  border-radius: 18px;
  padding: 24px 22px;
  display: flex;
  flex-direction: column;
  gap: 12px;
  align-items: center;
  text-align: center;
  min-width: 240px;
  max-width: 320px;
  width: 100%;
}

.overlay-card h2 {
  margin: 0;
  font-size: 22px;
  font-weight: 800;
  letter-spacing: -0.02em;
}

.overlay-score {
  margin: 0;
  font-size: 56px;
  font-weight: 800;
  font-variant-numeric: tabular-nums;
  letter-spacing: -0.04em;
  line-height: 1;
}

.overlay-card button {
  font: inherit;
  color: #fff;
  background: rgba(255, 255, 255, 0.10);
  border: 1px solid rgba(255, 255, 255, 0.22);
  border-radius: 999px;
  padding: 12px 20px;
  min-height: 44px;
  cursor: pointer;
  font-weight: 600;
  font-size: 14px;
  width: 100%;
  -webkit-tap-highlight-color: transparent;
}

.overlay-card button:active {
  background: rgba(255, 255, 255, 0.18);
}

.overlay-card .save-btn {
  background: #4f9eff;
  border-color: #4f9eff;
}

.overlay-card .save-btn:active {
  background: #3d8ae8;
}

/* ─── N-Back ───────────────────────────────────────────────
   위에서부터: 레벨/목숨 · 3×3 격자 · 판정 문구 · 트라이얼 게이지 · 큰 버튼. */
#game {
  flex-direction: column;
  justify-content: flex-start;
  align-items: stretch;
  gap: 14px;
  min-height: 0;
}

.nb-hud {
  display: flex;
  align-items: center;
  justify-content: space-between;
  min-height: 26px;
}

.nb-level {
  font-size: 14px;
  font-weight: 800;
  letter-spacing: 0.06em;
  color: #4f9eff;
  padding: 4px 12px;
  border-radius: 999px;
  background: rgba(79, 158, 255, 0.12);
  border: 1px solid rgba(79, 158, 255, 0.3);
}

.nb-lives { display: flex; gap: 7px; }

.nb-life {
  width: 13px;
  height: 13px;
  border-radius: 999px;
  background: #ff5a5a;
  box-shadow: 0 0 9px rgba(255, 90, 90, 0.45);
  transition: background 0.2s ease, box-shadow 0.2s ease;
}

.nb-life.gone { background: #2a2a2a; box-shadow: none; }

/* 3×3 격자 — 한 번에 한 칸만 켜진다 */
.nb-grid {
  margin: auto 0;
  align-self: center;
  width: min(100%, 300px);
  aspect-ratio: 1;
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 8px;
}

.nb-cell {
  border-radius: 12px;
  background: #15171c;
  border: 1px solid #262b35;
  transition: background 0.06s linear, box-shadow 0.06s linear, border-color 0.06s linear;
}

.nb-cell.on {
  background: #4f9eff;
  border-color: #7ab6ff;
  box-shadow: 0 0 22px rgba(79, 158, 255, 0.55);
}

.nb-msg {
  margin: 0 0 auto;
  min-height: 22px;
  text-align: center;
  font-size: 14px;
  font-weight: 700;
  color: #b8b8b8;
}

.nb-msg.ok { color: #6ee787; }
.nb-msg.bad { color: #ff6b6b; }

.nb-timer {
  height: 6px;
  border-radius: 999px;
  background: #1d1d1d;
  overflow: hidden;
}

.nb-timer span {
  display: block;
  height: 100%;
  width: 100%;
  border-radius: 999px;
  background: linear-gradient(to right, #4f9eff, #6ee787);
}

/* 한 손 엄지로 누르는 큰 버튼 */
.nb-btn {
  font: inherit;
  font-weight: 800;
  font-size: 19px;
  letter-spacing: 0.04em;
  color: #f5f5f5;
  background: #1e2a3a;
  border: 1px solid #33506f;
  border-radius: 16px;
  min-height: 78px;
  cursor: pointer;
  -webkit-tap-highlight-color: transparent;
  touch-action: manipulation;
  transition: background 0.1s ease, opacity 0.1s ease;
}

.nb-btn:active { background: #2a3b52; }
.nb-btn:disabled { opacity: 0.4; cursor: default; }

.overlay-sub {
  margin: 0;
  font-size: 15px;
  font-weight: 800;
  letter-spacing: 0.06em;
  color: #4f9eff;
}

@media (max-height: 680px) {
  .nb-grid { width: min(100%, 240px); }
  .nb-btn { min-height: 62px; font-size: 17px; }
}