:root {
  --bg0: #05040f;
  --bg1: #0b1024;
  --panel: #11132a;
  --panel2: #171a36;
  --text: #eef1ff;
  --muted: #8b90b8;
  --accent: #39f2ff;
  --accent2: #7b5cff;
  --danger: #ff2b4d;
  --shake-amount: 0px;
}

* { box-sizing: border-box; }

html[lang="en"] [data-lang="ja"], html[lang="ja"] [data-lang="en"] { display: none !important; }

html, body {
  margin: 0;
  padding: 0;
  min-height: 100%;
  background: var(--bg0);
  color: var(--text);
  font-family: "Segoe UI", system-ui, -apple-system, "Yu Gothic UI", "Hiragino Sans", sans-serif;
  overflow-x: hidden;
}

body {
  min-height: 100dvh;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: max(1.25rem, env(safe-area-inset-top)) max(0.75rem, env(safe-area-inset-right)) max(1.25rem, env(safe-area-inset-bottom)) max(0.75rem, env(safe-area-inset-left));
  position: relative;
}

.bg-gradient {
  position: fixed;
  inset: -10%;
  z-index: 0;
  background:
    radial-gradient(circle at 20% 25%, color-mix(in srgb, var(--accent) 32%, transparent), transparent 55%),
    radial-gradient(circle at 80% 70%, color-mix(in srgb, var(--accent2) 30%, transparent), transparent 55%),
    linear-gradient(160deg, var(--bg0), var(--bg1) 60%, #090a1c);
  filter: saturate(calc(1.15 + var(--heat, 0) * 0.4));
  animation: bg-drift 22s ease-in-out infinite alternate;
  transition: background 0.4s ease;
}

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

@keyframes bg-drift {
  0% { transform: scale(1) rotate(0deg); }
  100% { transform: scale(1.12) rotate(6deg); }
}

#fx-canvas {
  position: fixed;
  inset: 0;
  z-index: 1;
  pointer-events: none;
}

.fly-layer {
  position: fixed;
  inset: 0;
  z-index: 85;
  pointer-events: none;
}

.fly-text {
  position: fixed;
  left: 50%;
  top: 50%;
  transform: translate(-50%, -50%);
  font-weight: 900;
  font-size: clamp(2rem, 9vw, 4.5rem);
  color: var(--accent);
  text-shadow: 0 0 18px currentColor, 0 0 40px currentColor;
  pointer-events: none;
}
.fly-text.up { animation: fly-up-kf 0.9s ease-out forwards; }
.fly-text.down { animation: fly-down-kf 0.9s ease-in forwards; }
@keyframes fly-up-kf {
  0% { opacity: 0; transform: translate(-50%, -50%) scale(0.6); }
  18% { opacity: 1; transform: translate(-50%, -50%) scale(1.15); }
  100% { opacity: 0; transform: translate(-50%, -260%) scale(1.3); }
}
@keyframes fly-down-kf {
  0% { opacity: 0; transform: translate(-50%, -50%) scale(0.6); }
  18% { opacity: 1; transform: translate(-50%, -50%) scale(1.15); }
  100% { opacity: 0; transform: translate(-50%, 160%) scale(1.3); }
}

.mega-telop {
  position: fixed;
  top: 12%;
  left: -100%;
  white-space: nowrap;
  font-weight: 900;
  font-size: clamp(1.5rem, 7.5vw, 3.2rem);
  color: var(--accent2);
  text-shadow: 0 0 16px currentColor, 0 0 42px currentColor;
  z-index: 86;
  pointer-events: none;
}
.mega-telop.run { animation: mega-telop-kf 1.6s linear forwards; }
@keyframes mega-telop-kf {
  0% { left: -100%; opacity: 0; }
  10% { opacity: 1; }
  90% { opacity: 1; }
  100% { left: 110%; opacity: 0; }
}

.shockwave {
  position: fixed;
  border-radius: 50%;
  border: 2px solid var(--accent);
  opacity: 0.85;
  pointer-events: none;
  z-index: 86;
  transform: translate(-50%, -50%) scale(0.2);
}
.shockwave.run { animation: shockwave-kf 0.5s ease-out forwards; }
@keyframes shockwave-kf {
  0% { transform: translate(-50%, -50%) scale(0.2); opacity: 0.85; }
  100% { transform: translate(-50%, -50%) scale(1); opacity: 0; }
}

.flash-overlay {
  position: fixed;
  inset: 0;
  z-index: 80;
  background: #fff;
  opacity: 0;
  pointer-events: none;
  mix-blend-mode: overlay;
}
.flash-overlay.flash-active { animation: flash-kf 0.28s ease-out; }
@keyframes flash-kf {
  0% { opacity: 0.85; }
  100% { opacity: 0; }
}

.burst-rays {
  position: fixed;
  width: 60vmax;
  height: 60vmax;
  left: 50%;
  top: 50%;
  transform: translate(-50%, -50%) scale(0.2);
  border-radius: 50%;
  background: repeating-conic-gradient(from 0deg, color-mix(in srgb, var(--accent) 55%, transparent) 0deg 4deg, transparent 4deg 18deg);
  opacity: 0;
  pointer-events: none;
  z-index: 82;
  mix-blend-mode: screen;
}
.burst-rays.burst-active { animation: burst-kf 0.6s ease-out; }
@keyframes burst-kf {
  0% { opacity: 0; transform: translate(-50%, -50%) scale(0.2) rotate(0deg); }
  30% { opacity: 0.8; }
  100% { opacity: 0; transform: translate(-50%, -50%) scale(1.15) rotate(25deg); }
}

.result-ring {
  position: fixed;
  width: 10px;
  height: 10px;
  left: 50%;
  top: 50%;
  border-radius: 50%;
  border: 3px solid var(--accent);
  transform: translate(-50%, -50%);
  opacity: 0;
  pointer-events: none;
  z-index: 83;
}
.result-ring.ring-active { animation: result-ring-kf 0.65s ease-out; }
@keyframes result-ring-kf {
  0% { opacity: 0.9; width: 10px; height: 10px; }
  100% { opacity: 0; width: 140vmin; height: 140vmin; }
}

.lens-flare {
  position: fixed;
  left: 50%;
  top: 50%;
  width: 12px;
  height: 12px;
  border-radius: 50%;
  background: radial-gradient(circle, #fff 0%, color-mix(in srgb, var(--accent) 80%, transparent) 40%, transparent 70%);
  transform: translate(-50%, -50%) scale(0.5);
  opacity: 0;
  pointer-events: none;
  z-index: 84;
  mix-blend-mode: screen;
}
.lens-flare.flare-active { animation: flare-kf 0.5s ease-out; }
@keyframes flare-kf {
  0% { opacity: 0; transform: translate(-50%, -50%) scale(0.5); }
  20% { opacity: 1; transform: translate(-50%, -50%) scale(3); }
  100% { opacity: 0; transform: translate(-50%, -50%) scale(9); }
}

.app {
  position: relative;
  z-index: 2;
  width: 100%;
  display: flex;
  justify-content: center;
  --shake-amount: 0px;
}
.app.shake { animation: shake-kf 0.3s ease; }
@keyframes shake-kf {
  0% { transform: translate(0, 0); }
  20% { transform: translate(calc(var(--shake-amount) * -1), var(--shake-amount)); }
  40% { transform: translate(var(--shake-amount), calc(var(--shake-amount) * -1)); }
  60% { transform: translate(calc(var(--shake-amount) * -0.6), var(--shake-amount)); }
  80% { transform: translate(var(--shake-amount), calc(var(--shake-amount) * 0.6)); }
  100% { transform: translate(0, 0); }
}
.app.app-error { animation: error-hue-kf 0.9s linear infinite; }
@keyframes error-hue-kf {
  0%, 100% { filter: none; }
  50% { filter: hue-rotate(30deg) saturate(1.4); }
}

.mute-btn {
  position: fixed;
  top: max(0.9rem, env(safe-area-inset-top));
  right: max(0.9rem, env(safe-area-inset-right));
  z-index: 90;
  width: 2.6rem;
  height: 2.6rem;
  border-radius: 50%;
  border: 1px solid color-mix(in srgb, var(--accent) 50%, transparent);
  background: rgba(10, 12, 30, 0.65);
  color: var(--text);
  font-size: 1.2rem;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  backdrop-filter: blur(4px);
  touch-action: manipulation;
}
.mute-icon {
  width: 1.35rem;
  height: 1.35rem;
  fill: currentColor;
  stroke: currentColor;
  stroke-width: 1.8;
  stroke-linecap: round;
  stroke-linejoin: round;
}
.mute-icon[hidden] { display: none; }
.lang-toggle {
  position: fixed;
  top: max(0.9rem, env(safe-area-inset-top));
  left: max(0.9rem, env(safe-area-inset-left));
  z-index: 90;
  min-height: 2.6rem;
  padding: 0.45rem 0.85rem;
  border-radius: 999px;
  border: 1px solid color-mix(in srgb, var(--accent) 50%, transparent);
  background: rgba(10, 12, 30, 0.65);
  color: var(--text);
  font: inherit;
  font-size: 0.78rem;
  font-weight: 700;
  cursor: pointer;
  backdrop-filter: blur(4px);
  touch-action: manipulation;
}
.lang-toggle:active { transform: scale(0.94); }
.lang-toggle:focus-visible {
  outline: none;
  box-shadow: 0 0 0 3px var(--bg0), 0 0 0 6px var(--accent), 0 0 16px color-mix(in srgb, var(--accent) 65%, transparent);
}
.mute-btn:active { transform: scale(0.9); }
.mute-btn:focus-visible {
  outline: none;
  box-shadow: 0 0 0 3px var(--bg0), 0 0 0 6px var(--accent), 0 0 16px color-mix(in srgb, var(--accent) 65%, transparent);
}

.calc {
  width: min(420px, 94vw);
  background: linear-gradient(165deg, var(--panel), var(--panel2));
  border: 1px solid color-mix(in srgb, var(--accent) 35%, transparent);
  border-radius: 22px;
  padding: 1.1rem 1.1rem 1.4rem;
  box-shadow: 0 20px 60px rgba(0, 0, 0, 0.55), 0 0 40px color-mix(in srgb, var(--accent) 20%, transparent) inset;
  transition: border-color 0.3s ease;
}
.calc.zoom-pulse { animation: zoom-pulse-kf 0.4s ease-out; }
@keyframes zoom-pulse-kf {
  0% { transform: scale(1); }
  35% { transform: scale(1.035); }
  100% { transform: scale(1); }
}

.calc-title {
  margin: 0.2rem 0 0.9rem;
  font-size: 1.05rem;
  letter-spacing: 0.14em;
  text-align: center;
  font-weight: 800;
  color: var(--muted);
}
.calc-title span {
  color: var(--accent);
  text-shadow: 0 0 12px color-mix(in srgb, var(--accent) 70%, transparent);
}

.max-combo {
  margin: -0.35rem 0 0.7rem;
  text-align: center;
  font-size: 0.68rem;
  letter-spacing: 0.08em;
  color: var(--muted);
  opacity: 0.85;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}
.max-combo span {
  color: var(--accent);
  font-weight: 800;
}

.display {
  position: relative;
  background: rgba(3, 4, 14, 0.65);
  border: 1px solid color-mix(in srgb, var(--accent) 25%, transparent);
  border-radius: 16px;
  padding: 0.85rem 1rem 0.75rem;
  margin-bottom: 0.7rem;
  height: 5.95rem;
  overflow: hidden;
}
.display::before {
  content: "";
  position: absolute;
  inset: 0;
  background: repeating-linear-gradient(
    0deg,
    rgba(255, 255, 255, 0.035) 0px,
    rgba(255, 255, 255, 0.035) 1px,
    transparent 1px,
    transparent 3px
  );
  mix-blend-mode: overlay;
  pointer-events: none;
}

.expr {
  position: relative;
  height: 1.1rem;
  line-height: 1.1rem;
  font-size: clamp(0.72rem, 3vw, 0.95rem);
  color: var(--muted);
  font-family: "Consolas", "SFMono-Regular", Menlo, monospace;
  font-variant-numeric: tabular-nums;
  letter-spacing: 0.02em;
  text-align: right;
  white-space: nowrap;
  overflow: hidden;
}
.expr.has-badge { padding-left: 4.5rem; }

.current {
  position: relative;
  height: 3.25rem;
  font-family: "Consolas", "SFMono-Regular", Menlo, monospace;
  font-variant-numeric: tabular-nums;
  font-size: clamp(1.9rem, 8.5vw, 2.7rem);
  font-weight: 700;
  text-align: right;
  line-height: 3.25rem;
  white-space: nowrap;
  color: var(--text);
  text-shadow: 0 0 10px color-mix(in srgb, var(--accent) 35%, transparent);
}
.current.roll { animation: roll-kf 0.16s ease; }
@keyframes roll-kf {
  0% { transform: translateY(-35%) scale(0.92); opacity: 0.35; filter: blur(2px); }
  100% { transform: none; opacity: 1; filter: none; }
}
.current.result-pop {
  animation: result-pop-kf 0.5s cubic-bezier(.2,1.6,.4,1);
  text-shadow: 0 0 14px color-mix(in srgb, var(--accent) 60%, transparent), 0 0 34px color-mix(in srgb, var(--accent) 45%, transparent), 0 0 60px color-mix(in srgb, var(--accent2) 35%, transparent);
}
@keyframes result-pop-kf {
  0% { transform: scale(0.4); opacity: 0; }
  55% { transform: scale(1.25); opacity: 1; }
  100% { transform: scale(1); opacity: 1; }
}

.combo-badge {
  position: absolute;
  top: 0.5rem;
  left: 0.7rem;
  font-size: 0.72rem;
  font-weight: 800;
  letter-spacing: 0.06em;
  padding: 0.15rem 0.5rem;
  border-radius: 999px;
  color: #08101a;
  background: linear-gradient(120deg, var(--accent), var(--accent2));
  max-width: calc(100% - 1.4rem);
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}
.combo-badge.pop { animation: combo-pop-kf 0.25s ease; }
@keyframes combo-pop-kf {
  0% { transform: scale(0.7); }
  60% { transform: scale(1.25); }
  100% { transform: scale(1); }
}

.telop {
  height: 2.3rem;
  margin: 0 0.2rem 0.7rem;
  display: flex;
  align-items: center;
  justify-content: center;
  text-align: center;
  line-height: 1.25;
  overflow: hidden;
  font-size: 0.85rem;
  font-weight: 700;
  color: var(--accent);
  letter-spacing: 0.03em;
}
.telop.pop { animation: telop-pop-kf 0.32s ease; }
@keyframes telop-pop-kf {
  0% { transform: translateY(6px) scale(0.85); opacity: 0; }
  100% { transform: none; opacity: 1; }
}

.keys {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 0.55rem;
}

.btn {
  position: relative;
  overflow: hidden;
  padding: 0.95rem 0;
  border-radius: 14px;
  border: 1px solid rgba(255, 255, 255, 0.06);
  font-size: 1.15rem;
  font-weight: 700;
  color: var(--text);
  cursor: pointer;
  background: rgba(255, 255, 255, 0.04);
  transition: filter 0.15s ease;
  user-select: none;
  -webkit-appearance: none;
  appearance: none;
  -webkit-tap-highlight-color: transparent;
  touch-action: manipulation;
}
.btn:focus:not(:focus-visible) {
  outline: none;
  box-shadow: none;
}
.btn:focus-visible {
  outline: none;
  box-shadow: 0 0 0 3px var(--bg0), 0 0 0 6px var(--accent), 0 0 16px color-mix(in srgb, var(--accent) 65%, transparent);
}
.btn::after {
  content: "";
  position: absolute;
  inset: 0;
  background: linear-gradient(120deg, rgba(255, 255, 255, 0.18), transparent 45%);
  opacity: 0;
  transition: opacity 0.2s ease;
  pointer-events: none;
}
@media (hover: hover) and (pointer: fine) {
  .btn:hover { filter: brightness(1.15); }
  .btn:hover::after { opacity: 1; }
}
.btn.pressed { animation: btn-press-kf 0.32s cubic-bezier(.34,1.56,.64,1); }
@keyframes btn-press-kf {
  0% { transform: scale(1); box-shadow: none; }
  30% { transform: scale(0.82) rotate(-2deg); box-shadow: 0 0 18px 4px color-mix(in srgb, var(--accent) 55%, transparent); }
  62% { transform: scale(1.12); box-shadow: 0 0 30px 8px color-mix(in srgb, var(--accent) 35%, transparent); }
  100% { transform: scale(1); box-shadow: none; }
}

.btn-num { background: rgba(255, 255, 255, 0.055); }
.btn-fn { background: rgba(139, 144, 184, 0.18); color: var(--muted); }
.btn-op {
  background: linear-gradient(140deg, color-mix(in srgb, var(--accent) 28%, transparent), color-mix(in srgb, var(--accent2) 24%, transparent));
  color: var(--text);
}
.btn-eq {
  background: linear-gradient(140deg, var(--accent), var(--accent2));
  color: #08101a;
  font-size: 1.3rem;
}

.ripple {
  position: absolute;
  border-radius: 50%;
  background: currentColor;
  opacity: 0.5;
  pointer-events: none;
  mix-blend-mode: screen;
  animation: ripple-kf 0.5s ease-out forwards;
}
@keyframes ripple-kf {
  from { transform: scale(0); opacity: 0.55; }
  to { transform: scale(2.6); opacity: 0; }
}

.climax-overlay {
  position: fixed;
  inset: 0;
  z-index: 92;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 1.1rem;
  background: rgba(3, 4, 16, 0.78);
  backdrop-filter: blur(3px);
  pointer-events: none;
}
.climax-caption {
  font-size: clamp(1.1rem, 4.6vw, 1.7rem);
  font-weight: 800;
  color: var(--accent);
  text-shadow: 0 0 16px color-mix(in srgb, var(--accent) 70%, transparent);
  text-align: center;
  padding: 0 1rem;
  min-height: 2.6em;
  line-height: 1.3;
  display: flex;
  align-items: center;
  justify-content: center;
}
.loading-bar {
  width: min(80vw, 380px);
  height: 14px;
  border: 2px solid var(--accent);
  border-radius: 999px;
  overflow: hidden;
  background: rgba(255, 255, 255, 0.06);
}
.loading-fill {
  height: 100%;
  width: 0%;
  background: linear-gradient(90deg, var(--accent), var(--accent2));
}

.error-overlay {
  position: fixed;
  inset: 0;
  z-index: 95;
  display: flex;
  align-items: center;
  justify-content: center;
  background: rgba(40, 0, 6, 0.55);
  pointer-events: none;
}
.error-text {
  color: var(--danger);
  font-size: clamp(1.7rem, 8vw, 3.2rem);
  font-weight: 900;
  text-align: center;
  text-shadow: 0 0 20px var(--danger);
  animation: glitch-kf 0.25s infinite steps(2);
}
.error-text small { font-size: 0.4em; color: #ffb3c0; }
@keyframes glitch-kf {
  0% { transform: translate(0, 0); }
  20% { transform: translate(-4px, 2px); }
  40% { transform: translate(3px, -2px); }
  60% { transform: translate(-2px, -3px); }
  80% { transform: translate(2px, 3px); }
  100% { transform: translate(0, 0); }
}

.climax-overlay[hidden], .error-overlay[hidden] { display: none; }

@media (max-width: 380px) {
  .calc { padding: 0.9rem 0.75rem 1.1rem; border-radius: 18px; }
  .btn { padding: 0.8rem 0; font-size: 1.02rem; }
}

@media (max-height: 520px) {
  body { align-items: flex-start; padding-top: 0.5rem; padding-bottom: 0.5rem; }
  .calc { padding: 0.7rem 0.9rem 0.9rem; border-radius: 16px; }
  .calc-title { margin: 0.1rem 0 0.45rem; font-size: 0.95rem; }
  .max-combo { display: none; }
  .display { height: 4.7rem; padding: 0.5rem 0.9rem; margin-bottom: 0.5rem; }
  .expr { height: 1rem; line-height: 1rem; }
  .current { height: 2.7rem; line-height: 2.7rem; font-size: clamp(1.5rem, 7vw, 2.2rem); }
  .telop { height: 1.5rem; margin-bottom: 0.5rem; }
  .keys { gap: 0.4rem; }
  .btn { padding: 0.55rem 0; font-size: 1rem; }
  .btn-eq { font-size: 1.1rem; }
}

@media (prefers-reduced-motion: reduce) {
  .bg-gradient { animation: none; }
  .app.shake { animation: none; }
  .app.app-error { animation: none; }
  .flash-overlay.flash-active { animation: none; }
  .shockwave.run, .burst-rays.burst-active, .result-ring.ring-active,
  .lens-flare.flare-active, .calc.zoom-pulse, .mega-telop.run { animation: none; }
}