/* ============================================================
   MathMon — style.css
   ============================================================ */
@import url('https://fonts.googleapis.com/css2?family=Fredoka:wght@400;500;600;700&family=Nunito:wght@700;800;900&family=Zen+Maru+Gothic:wght@700;900&display=swap');

:root {
  --font-num: 'Fredoka', 'Nunito', 'Zen Maru Gothic', sans-serif;
  --theme:    #4A9FE0;
  --theme-dk: #2D7DC0;
  --white:    #FFFFFF;
  --ink:      #1C1B3A;
  --ink-2:    #5E5A7A;
  --green:    #1DB954;
  --red:      #FF4040;
  --font:     'Nunito', 'Zen Maru Gothic', sans-serif;
  /* キャンバス・解答欄の左右マージンと同様のルール（記載欄・キーボード・答えるの間隔も統一） */
  --answer-margin-x: 16px;
  --answer-gap: 16px;
}
.num-pop { font-family: var(--font-num); }

*, *::before, *::after {
  box-sizing: border-box; margin: 0; padding: 0;
  -webkit-tap-highlight-color: transparent;
  user-select: none; -webkit-user-select: none;
}
html, body { height: 100%; background: #0F0E1A; font-family: var(--font); }

/* ══════════════════════════════════════════════════
   APP
   ══════════════════════════════════════════════════ */
#app {
  position: relative;
  width: 100%; max-width: 430px;
  height: 100dvh; height: 100vh;
  min-height: -webkit-fill-available;
  margin: 0 auto;
  background: var(--theme);
  transition: background .5s cubic-bezier(.4,0,.2,1);
  display: flex; flex-direction: column; align-items: center;
  overflow: hidden;
  border-radius: 28px;
}

#main-content {
  flex: 1;
  min-height: 0;
  overflow-y: auto;
  -webkit-overflow-scrolling: touch;
  width: 100%;
  display: flex; flex-direction: column; align-items: center;
  padding: clamp(4px, 0.8dvh, 8px) 0 clamp(6px, 1dvh, 12px);
}

#app::before {
  content: ''; position: absolute; border-radius: 50%;
  pointer-events: none; background: rgba(255,255,255,.06);
  width: 260px; height: 260px; top: -80px; left: -80px;
}
#app::after {
  content: ''; position: absolute; border-radius: 50%;
  pointer-events: none; background: rgba(0,0,0,.04);
  width: 180px; height: 180px; bottom: 20px; right: -60px;
}

#app.react-correct { animation: monHappy .55s ease both; }
#app.react-wrong   { animation: monSad .5s ease both; }
@keyframes monHappy { 0%,100%{filter:brightness(1)} 35%{filter:brightness(1.2) saturate(1.1)} }
@keyframes monSad   { 0%,100%{filter:brightness(1)} 60%{filter:brightness(.92) saturate(.85)} }

/* ══════════════════════════════════════════════════
   ANTENNAE
   ══════════════════════════════════════════════════ */
#antennae {
  position: absolute; top: 0; left: 0; right: 0; height: 0;
  display: flex; justify-content: space-between;
  padding: 0 56px; z-index: 2; pointer-events: none;
}
.ant { display: flex; flex-direction: column-reverse; align-items: center; transform-origin: bottom center; }
#ant-l { transform: rotate(-12deg) translateY(-58px); }
#ant-r { transform: rotate(12deg)  translateY(-58px); }
.ant-stem { width: 7px; height: 48px; background: var(--theme-dk); border-radius: 4px; transition: background .5s; }
.ant-ball  { width: 18px; height: 18px; background: var(--theme-dk); border-radius: 50%; margin-bottom: -2px; transition: background .5s; }
.ant.bounce { animation: antB .55s cubic-bezier(.36,.07,.19,.97) both; }
#ant-r.bounce { animation: antBR .55s cubic-bezier(.36,.07,.19,.97) both; }
@keyframes antB  { 0%,100%{transform:rotate(-12deg) translateY(-58px)} 35%{transform:rotate(-12deg) translateY(-78px) scaleY(1.1)} 65%{transform:rotate(-12deg) translateY(-52px)} }
@keyframes antBR { 0%,100%{transform:rotate(12deg)  translateY(-58px)} 35%{transform:rotate(12deg)  translateY(-78px) scaleY(1.1)} 65%{transform:rotate(12deg)  translateY(-52px)} }

/* ══════════════════════════════════════════════════
   下部バー（問題集・機能・ステータス）
   ══════════════════════════════════════════════════ */
#bottom-bar {
  flex-shrink: 0;
  display: flex;
  align-items: center;
  gap: 10px;
  width: calc(100% - 16px);
  margin: 0 8px 6px;
  padding: 14px;
  background: white;
  border-radius: 18px;
  border: 1px solid rgba(0,0,0,.06);
  z-index: 3;
}

.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; }

#diff-section {
  position: relative;
  flex-shrink: 0;
}
#diff-toggle {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 40px;
  height: 40px;
  background: #f8f8f8;
  border: 1px solid rgba(0,0,0,.06);
  border-radius: 12px;
  color: var(--theme);
  cursor: pointer;
  transition: background .18s ease, border-color .18s ease;
}
#diff-toggle:hover {
  background: white;
  border: 1px solid var(--theme);
}
#diff-toggle:active {
  background: #ebebeb;
}
#diff-toggle #diff-toggle-icon {
  flex-shrink: 0;
}
#diff-toggle[aria-expanded="true"] {
  background: var(--theme);
  border: none;
  color: white;
}
#diff-drawer {
  position: absolute;
  bottom: calc(100% + 20px);
  left: -14px;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 8px;
  padding: 12px;
  background: white;
  border-radius: 16px;
  border: 1px solid rgba(0,0,0,.06);
  animation: drawerFade .2s ease both;
  width: min(260px, calc(100vw - 40px));
  z-index: 20;
}
#diff-drawer.hidden { display: none; }
@keyframes drawerFade {
  from { opacity: 0; }
  to { opacity: 1; }
}
#diff-drawer .diff-btn {
  font-size: .7rem;
  font-weight: 800;
  padding: 6px 8px;
  border-radius: 10px;
  min-width: 0;
  text-align: center;
  background: #f8f8f8;
  border: none;
  color: var(--ink-2);
  font-family: var(--font);
  cursor: pointer;
  transition: background .15s ease;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}
#diff-drawer .diff-btn:hover {
  background: #f0f0f0;
}
#diff-drawer .diff-btn.active {
  background: var(--theme);
  color: white;
}

/* NAV — ステータスバー */
#nav {
  flex: 1;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 6px;
  pointer-events: none;
}

#nav-center {
  flex: 1;
  min-width: 0;
  max-width: none;
  position: relative;
  height: 20px;
  display: flex; align-items: center; justify-content: center;
  background: #f0f0f0;
  border-radius: 10px;
  overflow: hidden;
}
#prog-wrap { position: absolute; inset: 0; }
#prog-bar {
  height: 100%; width: 0%;
  background: var(--theme);
  transition: width .55s cubic-bezier(.4,0,.2,1);
}
#q-val {
  position: relative; z-index: 1;
  font-size: .68rem; font-weight: 800;
  color: var(--ink); letter-spacing: .5px;
}

#nav-score {
  display: flex; align-items: center; gap: 4px;
  background: #f0f0f0;
  padding: 5px 10px;
  border-radius: 10px;
  font-size: .68rem; font-weight: 800;
  color: var(--ink);
}

/* ══════════════════════════════════════════════════
   CHARACTER — 目 + 眉 + 笑顔
   ══════════════════════════════════════════════════ */
#character {
  display: flex; flex-direction: column; align-items: center;
  gap: 6px;
  padding-top: 32px;
  margin: clamp(8px, 3.5dvh, 40px) 0 clamp(6px, 3dvh, 40px);
  flex-shrink: 1;
  position: relative; z-index: 2;
}

#eyes {
  display: flex; gap: 40px;
}

.eye-unit {
  display: flex; flex-direction: column; align-items: center;
  gap: 7px;
}

/* Eyebrow */
.brow {
  width: 32px; height: 7px;
  background: var(--theme-dk);
  border-radius: 6px;
  transition: transform .35s cubic-bezier(.4,0,.2,1), background .5s;
  transform-origin: center;
}

/* Default (happy) — 眉を少し上げてフレンドリーに */
.eye-unit:first-child .brow { transform: rotate(-5deg) translateY(-1px); }
.eye-unit:last-child  .brow { transform: rotate(5deg)  translateY(-1px); }

/* Eye expressions */
#eyes.excited   .eye-unit:first-child .brow { transform: rotate(-14deg) translateY(-6px); }
#eyes.excited   .eye-unit:last-child  .brow { transform: rotate(14deg)  translateY(-6px); }
#eyes.happy     .eye-unit:first-child .brow { transform: rotate(-5deg)  translateY(-1px); }
#eyes.happy     .eye-unit:last-child  .brow { transform: rotate(5deg)   translateY(-1px); }
#eyes.sad       .eye-unit:first-child .brow { transform: rotate(12deg)  translateY(4px); }
#eyes.sad       .eye-unit:last-child  .brow { transform: rotate(-12deg) translateY(4px); }
#eyes.surprised .eye-unit:first-child .brow { transform: rotate(-18deg) translateY(-10px); }
#eyes.surprised .eye-unit:last-child  .brow { transform: rotate(18deg)  translateY(-10px); }

.eye {
  width: 70px; height: 70px;
  background: white;
  border-radius: 50%;
  position: relative; overflow: hidden;
  transition: transform .25s cubic-bezier(.4,0,.2,1);
}
#eyes.happy     .eye { transform: scaleY(1); }
#eyes.excited   .eye { transform: scaleY(1.12); }
#eyes.sad       .eye { transform: scaleY(.58) translateY(8px); }
#eyes.surprised .eye { transform: scaleY(1.18) scaleX(1.08); }

.pupil {
  position: absolute;
  width: 30px; height: 30px;
  background: var(--ink);
  border-radius: 50%;
  top: 55%; left: 50%;
  transform: translate(-50%, -50%);
  transition: transform .07s ease-out, width .25s, height .25s, top .25s;
}
#eyes.excited   .pupil { width: 34px; height: 34px; top: 52%; }
#eyes.sad       .pupil { top: 70%; width: 20px; height: 12px; border-radius: 50% 50% 0 0; }
#eyes.surprised .pupil { width: 28px; height: 28px; top: 50%; }
.pupil::after {
  content: ''; position: absolute;
  width: 10px; height: 10px;
  background: rgba(255,255,255,.72);
  border-radius: 50%; top: 12%; left: 16%;
}

/* Smile / frown arc */
#smile {
  width: 36px; height: 20px;
  border: 4px solid var(--theme-dk);
  border-top: none;
  border-radius: 0 0 36px 36px;
  transition: all .38s cubic-bezier(.4,0,.2,1), border-color .5s;
  flex-shrink: 0;
}
#character.state-correct #smile {
  width: 46px; height: 26px;
}
#character.state-surprised #smile {
  width: 18px; height: 18px;
  border: 3px solid var(--theme-dk);
  border-top: 3px solid var(--theme-dk);
  border-radius: 50%;
  transform: none;
}
#character.state-wrong #smile {
  width: 32px; height: 14px;
  border-radius: 36px 36px 0 0;
  border-bottom: none;
  border-top: 3px solid var(--theme-dk);
  transform: translateY(6px);
}

.diff-btn {
  background: rgba(255,255,255,.2); border: none; border-radius: 8px;
  color: rgba(255,255,255,.9); font-family: var(--font);
  font-size: .68rem; font-weight: 800; padding: 6px 12px;
  cursor: pointer; transition: all .2s; white-space: nowrap;
}
.diff-btn.active, .diff-btn:hover {
  background: rgba(255,255,255,.9); color: var(--theme);
}


/* ══════════════════════════════════════════════════
   PROBLEM
   ══════════════════════════════════════════════════ */
#problem-card {
  width: calc(100% - (var(--answer-margin-x) * 2)); background: transparent;
  padding: 6px 0 10px; text-align: center; margin-bottom: 2px;
  position: relative; z-index: 2;
  animation: cardIn .35s cubic-bezier(.175,.885,.32,1.275) both;
  font-family: var(--font-num);
}
@keyframes cardIn { from{opacity:0;transform:translateY(12px) scale(.97)} to{opacity:1;transform:none} }
#prob-label {
  display: inline-block; font-size: .62rem; font-weight: 800;
  font-family: var(--font-num);
  text-transform: uppercase; letter-spacing: 2.5px; color: white;
  background: rgba(255,255,255,.16); padding: 3px 14px;
  border-radius: 50px; margin-bottom: 8px;
}
#prob-eq { display: flex; align-items: center; justify-content: center; gap: 8px; flex-wrap: wrap; box-sizing: content-box; margin-bottom: 16px; font-family: var(--font-num); }
#num-a, #num-b  { font-family: var(--font-num); font-size: clamp(3.2rem,12vw,4.2rem); font-weight: 900; color: white; line-height: 1; }
#op-sym  { font-family: var(--font-num); font-size: clamp(2.2rem,8vw,3rem); font-weight: 900; color: rgba(255,255,255,.5); line-height: 1; }
#eq-sym  { font-family: var(--font-num); font-size: clamp(1.8rem,6vw,2.4rem); font-weight: 700; color: rgba(255,255,255,.3); line-height: 1; }
#ans-mark {
  font-family: var(--font-num); font-size: clamp(3.2rem,12vw,4.2rem);
  font-weight: 900; color: rgba(255,255,255,.9);
  line-height: 1;
  display: inline-block; transform-style: preserve-3d;
}
#ans-mark.pulsing { animation: qPulse 1.4s ease-in-out infinite; }
@keyframes qPulse { 0%,100%{opacity:1;transform:scale(1)} 50%{opacity:.35;transform:scale(.82)} }
#ans-mark.flip-out { animation: flipOut .2s ease both; }
#ans-mark.flip-in  { animation: flipIn  .2s ease both; }
@keyframes flipOut { from{transform:rotateY(0) scale(1)} to{transform:rotateY(-90deg) scale(.7);opacity:.2} }
@keyframes flipIn  { from{transform:rotateY(90deg) scale(.7);opacity:.2} to{transform:rotateY(0) scale(1.15);opacity:1} }
#ans-mark.revealed {
  animation: revealSettle .25s .2s ease both;
  color: #4AE080 !important;
}
@keyframes revealSettle { 0%{transform:scale(1.15)} 60%{transform:scale(1.3)} 100%{transform:scale(1)} }

/* ══════════════════════════════════════════════════
   ANSWER ZONE
   ══════════════════════════════════════════════════ */
#answer-zone {
  width: calc(100% - (var(--answer-margin-x) * 2));
  display: flex; flex-direction: column; gap: var(--answer-gap);
  align-items: stretch;
  position: relative; z-index: 2;
}

#answer-mode-wrap {
  position: relative;
  width: 100%;
  min-height: clamp(64px, 16dvh, 120px);
}
#answer-mode-wrap .mode-panel {
  width: 100%;
  transition: opacity .2s ease;
}
#answer-mode-wrap .mode-panel.hidden { display: none; }

#canvas-wrap {
  position: relative;
  border-radius: 22px; overflow: hidden;
  background: white;
}
#canvas-wrap.shake { animation: shake .42s ease both; }
@keyframes shake {
  0%,100%{transform:translateX(0)}
  15%{transform:translateX(-9px) rotate(-.6deg)}
  30%{transform:translateX(9px) rotate(.6deg)}
  50%{transform:translateX(-5px) rotate(-.3deg)}
  70%{transform:translateX(5px) rotate(.3deg)}
  85%{transform:translateX(-2px)}
}
#draw-canvas { display:block; width:100%; min-height: clamp(64px, 16dvh, 120px); aspect-ratio:2/1; touch-action:none; cursor:crosshair; }

#canvas-clear-btn {
  position: absolute; bottom: 10px; right: 12px;
  background: rgba(0,0,0,.07); border: none; border-radius: 50px;
  font-family: var(--font); font-size: .74rem; font-weight: 800;
  color: var(--ink-2); padding: 6px 12px; cursor: pointer;
  display: flex; align-items: center; gap: 5px;
  transition: background .15s, color .15s;
}
#canvas-clear-btn:hover { background: rgba(0,0,0,.12); }
#canvas-clear-btn.hidden { display: none; }

#canvas-wrap #numpad-toggle {
  position: absolute;
  top: 10px;
  right: 12px;
  background: rgba(0,0,0,.07);
  border: none;
  border-radius: 50px;
  font-family: var(--font);
  font-size: .74rem;
  font-weight: 800;
  color: var(--ink-2);
  padding: 6px 12px;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: background .15s, color .15s;
}
#canvas-wrap #numpad-toggle:hover {
  background: rgba(0,0,0,.12);
}
#canvas-wrap #numpad-toggle:active {
  background: rgba(0,0,0,.04);
}
#canvas-wrap #numpad-toggle.active {
  background: var(--theme);
  color: white;
}
#canvas-wrap #numpad-toggle.hidden { display: none; }

/* 認識結果エリア — 答えの出るエリア */
#recognized-wrap {
  display: flex; justify-content: center; align-items: center;
  min-height: 0;
}
.recognized-num {
  width: 72px; height: 72px;
  border-radius: 16px;
  font-family: var(--font-num);
  font-size: 2.4rem; font-weight: 800;
  color: var(--ink);
  background: white;
  display: flex; align-items: center; justify-content: center;
  animation: popBadge .28s cubic-bezier(.175,.885,.32,1.275) both;
  letter-spacing: -0.02em;
}
.recognized-num.hidden { display: none; }
@keyframes popBadge { from{transform:scale(0.9);opacity:0} to{transform:scale(1);opacity:1} }

/* Input Actions */
#input-actions {
  display: flex; gap: 10px; align-items: stretch;
}
#input-actions.hidden { display: none; }

#done-btn {
  flex: 1;
  background: rgba(255,255,255,.15); color: white;
  border: 2.5px solid rgba(255,255,255,.38); border-radius: 50px;
  font-family: var(--font); font-size: 1.15rem; font-weight: 900;
  padding: clamp(10px, 1.8dvh, 14px) 16px; cursor: pointer;
  transition: all .15s ease;
  backdrop-filter: blur(6px); -webkit-backdrop-filter: blur(6px);
}
#done-btn:hover:not(:disabled) { background: rgba(255,255,255,.28); transform: translateY(-1px); }
#done-btn:active:not(:disabled){ background: rgba(255,255,255,.1); transform: translateY(1px); }
#done-btn:disabled { opacity: .45; cursor: wait; }
#done-btn.hidden { display: none; }

/* Numpad */
#numpad {
  display: flex;
  flex-direction: column;
  gap: 20px;
  animation: numpadIn .26s cubic-bezier(.2,.9,.2,1) both;
}
#numpad.hidden { display: none; }
@keyframes numpadIn { from { opacity: 0; transform: translateY(8px) scale(.98); } to { opacity: 1; transform: none; } }

#numpad-display-wrap {
  position: relative;
  border-radius: 22px;
  overflow: hidden;
}
#handwrite-toggle {
  position: absolute;
  top: 10px;
  right: 12px;
  z-index: 2;
  background: rgba(0,0,0,.07);
  border: none;
  border-radius: 50px;
  font-family: var(--font);
  font-size: .74rem;
  font-weight: 800;
  color: var(--ink-2);
  padding: 6px 12px;
  cursor: pointer;
  transition: background .15s, color .15s;
}
#handwrite-toggle:hover {
  background: rgba(0,0,0,.12);
}
#handwrite-toggle:active {
  background: rgba(0,0,0,.04);
}
#handwrite-toggle.hidden { display: none; }
#numpad-display {
  position: relative;
  width: 100%;
  text-align: center;
  font-size: clamp(2.4rem, 5dvh, 3.4rem);
  font-weight: 900;
  color: var(--ink);
  min-height: clamp(64px, 16dvh, 120px);
  letter-spacing: 6px;
  background: white;
  border: none;
  border-radius: 22px;
  padding: clamp(12px, 2dvh, 20px) 14px;
  display: flex;
  align-items: center;
  justify-content: center;
}
#numpad-line-canvas {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  display: block;
  pointer-events: none;
}

#numpad-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: clamp(5px, 0.9dvh, 8px); }
.nk {
  background: rgba(255,255,255,.96);
  border: none;
  border-radius: 14px;
  color: white; font-family: var(--font-num);
  font-size: 1.4rem;
  font-weight: 800;
  color: #2B2B4E;
  padding: clamp(8px, 1.5dvh, 12px) 0;
  cursor: pointer;
  transition: transform .08s ease, background .2s ease;
  display: flex; align-items: center; justify-content: center;
}
.nk:hover  { background: white; }
.nk:active { transform: scale(.95); }
.nk-del {
  background: rgba(0,0,0,.14);
  color: rgba(255,255,255,.92);
  font-size: 1rem;
}
.nk-del:hover { background: rgba(0,0,0,.18); }
.nk-go  {
  background: rgba(255,255,255,.15);
  color: white;
  border: 2.5px solid rgba(255,255,255,.38);
  border-radius: 50px;
  font-family: var(--font);
  font-size: 1.15rem;
  font-weight: 900;
  white-space: nowrap;
  grid-column: 1 / -1;
  padding: clamp(10px, 1.8dvh, 14px) 16px;
  backdrop-filter: blur(6px); -webkit-backdrop-filter: blur(6px);
  margin-top: 12px;
  margin-bottom: 12px;
}
.nk-go:hover { background: rgba(255,255,255,.28); }

/* Feedback */
#feedback {
  font-family: var(--font); font-size: .95rem; font-weight: 800; color: white;
  text-align: center; min-height: 1.3rem; margin-top: 16px;
  position: relative; z-index: 2;
  transition: opacity .35s ease;
}
#feedback:empty { visibility: hidden; }

/* Next Button */
#next-btn {
  width: calc(100% - (var(--answer-margin-x) * 2));
  background: white; color: var(--theme);
  position: relative; z-index: 2;
  border: none; border-radius: 50px;
  font-family: var(--font); font-size: 1.1rem; font-weight: 900;
  padding: clamp(12px, 2dvh, 18px); cursor: pointer;
  transition: color .5s, transform .1s;
  animation: btnIn .4s cubic-bezier(.175,.885,.32,1.275) both;
  margin-top: 4px;
}
#next-btn.disabled { pointer-events: none; opacity: .45; }
#next-btn:hover  { transform: translateY(-2px); }
#next-btn:active { transform: translateY(4px); }
#next-btn.hidden { display: none; }
@keyframes btnIn { from{opacity:0;transform:translateY(16px) scale(.95)} to{opacity:1;transform:none} }

/* ══════════════════════════════════════════════════
   NUMPAD MODE — キーボード表示時（手書きと切り替え）
   ══════════════════════════════════════════════════ */
#app:has(#numpad:not(.hidden)) #recognized-wrap,
#app:has(#numpad:not(.hidden)) #input-actions {
  display: none;
}

/* ══════════════════════════════════════════════════
   カラーパレットボタン（右下・可愛い）
   ══════════════════════════════════════════════════ */
#palette-fab {
  flex-shrink: 0;
  width: 42px; height: 42px;
  border-radius: 50%;
  background: linear-gradient(145deg, rgba(255,255,255,.5), rgba(255,255,255,.25));
  border: 2px solid rgba(255,255,255,.4);
  cursor: pointer; z-index: 10;
  display: flex; align-items: center; justify-content: center;
  transition: transform .25s cubic-bezier(.34,1.56,.64,1);
}
#palette-fab:hover {
  transform: scale(1.1);
}
#palette-fab:active { transform: scale(.92); }
#palette-fab.active {
  transform: scale(1.05);
}
#fab-dot {
  width: 26px; height: 26px;
  border-radius: 50%;
  background: var(--theme);
  transition: background .4s ease;
}

/* ══════════════════════════════════════════════════
   カラーピッカー（#app デバイス内のみに表示）
   ══════════════════════════════════════════════════ */
#color-picker-sheet {
  position: absolute;
  inset: 0;
  z-index: 50;
  overflow: hidden;
  touch-action: none;
}
#color-picker-sheet.hidden { display: none; }

#color-picker-backdrop {
  position: absolute; inset: 0;
  background: radial-gradient(circle at center, rgba(9,10,20,.28), rgba(7,8,16,.5));
  border: none; cursor: pointer;
  animation: fadeIn .24s ease both;
}

#color-balls-cup {
  position: absolute;
  inset: 0;
  overflow: hidden;
  pointer-events: none;
  animation: fadeIn .22s ease both;
}

.color-ball {
  position: absolute;
  border-radius: 50%;
  cursor: grab;
  pointer-events: auto;
  touch-action: none;
  opacity: 0;
  filter: none;
  transition: opacity 0.35s cubic-bezier(0.34, 1.56, 0.64, 1),
              transform 0.2s cubic-bezier(0.34, 1.2, 0.64, 1);
}
.color-ball.ball-active { opacity: 1; }
.color-ball:hover { transform: scale(1.06); }
.color-ball.grabbed {
  cursor: grabbing;
  transform: scale(1.22);
  z-index: 10;
}

/* ══════════════════════════════════════════════════
   PARTICLES / EFFECTS
   ══════════════════════════════════════════════════ */
#burst-layer { position:fixed;inset:0;pointer-events:none;z-index:900;overflow:hidden; }
.burst-p {
  position: fixed; pointer-events: none;
  transform: translate(-50%,-50%);
  animation: burstOut 1.5s cubic-bezier(.2,.6,.2,1) forwards;
  font-size: 16px; line-height: 1; font-weight: 900;
}
@keyframes burstOut {
  0%   { opacity:1; transform:translate(-50%,-50%) scale(1.2) rotate(0deg); }
  70%  { opacity:1; transform:translate(calc(-50% + var(--tx)),calc(-50% + var(--ty))) scale(.85) rotate(var(--rot)); }
  100% { opacity:0; transform:translate(calc(-50% + var(--tx)),calc(-50% + var(--ty))) scale(.2) rotate(var(--rot)); }
}

/* クラッカー（左右からパン・パン） */
.cracker-p{
  position:fixed;
  pointer-events:none;
  transform:translate(-50%,-50%);
  z-index:900;
  will-change:transform,opacity;
  opacity: 0;
  animation:crackerFly var(--dur, 1050ms) cubic-bezier(.12,.9,.18,1) both;
  animation-delay: var(--delay, 0ms);
}
.cracker-p.tri{
  clip-path:polygon(50% 0%, 0% 100%, 100% 100%);
}
@keyframes crackerFly{
  0%{
    opacity:0;
    transform:translate(calc(-50% + var(--sx, 0px)),calc(-50% + var(--sy, 0px))) scale(.65) rotate(0deg);
  }
  5%{
    opacity:1;
    transform:translate(calc(-50% + var(--sx, 0px)),calc(-50% + var(--sy, 0px))) scale(1.08) rotate(var(--rot0, 0deg));
  }
  18%{
    opacity:1;
    transform:translate(calc(-50% + var(--tx0, 0px)),calc(-50% + var(--ty0, 0px))) scale(1) rotate(var(--rot0, 0deg));
  }
  55%{
    opacity:1;
    transform:translate(calc(-50% + var(--tx1)),calc(-50% + var(--ty1))) scale(1) rotate(var(--rot1, 0deg));
  }
  85%{
    opacity:1;
    transform:translate(calc(-50% + var(--tx2)),calc(-50% + var(--ty2))) scale(.95) rotate(var(--rot2, 0deg));
  }
  100%{
    opacity:0;
    transform:translate(calc(-50% + var(--tx2)),calc(-50% + var(--ty2))) scale(.9) rotate(var(--rot2, 0deg));
  }
}
.ring-expand {
  position:fixed;border-radius:50%;pointer-events:none;
  animation:ringOut 1.1s ease-out forwards;z-index:850;
}
@keyframes ringOut { 0%{transform:translate(-50%,-50%) scale(0);opacity:.7} 60%{transform:translate(-50%,-50%) scale(3.5);opacity:.4} 100%{transform:translate(-50%,-50%) scale(4);opacity:0} }

/* ══════════════════════════════════════════════════
   STREAK BANNER
   ══════════════════════════════════════════════════ */
.streak-banner {
  position:fixed;top:50%;left:50%;
  transform:translate(-50%,-50%) scale(0);
  background:white;color:var(--ink);
  font-family:var(--font);font-size:1.5rem;font-weight:900;
  padding:14px 28px;border-radius:50px;
  z-index:800;pointer-events:none;white-space:nowrap;
  animation:sBanPop .7s cubic-bezier(.175,.885,.32,1.275) forwards,
            sBanFade 2.2s ease 1.4s forwards;
}
@keyframes sBanPop  { from{transform:translate(-50%,-50%) scale(0);opacity:0} to{transform:translate(-50%,-50%) scale(1);opacity:1} }
@keyframes sBanFade { to{ opacity:0 } }

/* ══════════════════════════════════════════════════
   MODAL
   ══════════════════════════════════════════════════ */
#modal {
  position:fixed;inset:0;background:rgba(15,14,26,.65);
  backdrop-filter:blur(10px);-webkit-backdrop-filter:blur(10px);
  display:flex;align-items:center;justify-content:center;
  z-index:1000;animation:fadeIn .2s ease;
}
#modal.hidden{display:none}
#modal-box {
  background:white;border-radius:32px;padding:40px 44px;
  text-align:center;
  animation:modalPop .5s cubic-bezier(.175,.885,.32,1.275) both;
  max-width:290px;width:86%;
}
@keyframes modalPop { from{opacity:0;transform:scale(.5) translateY(20px)} to{opacity:1;transform:none} }
#modal-icon {
  font-size: 3rem; line-height: 1; letter-spacing: 6px;
  color: #FFD93D;
  margin-bottom: 10px;
  animation: iconSpin .7s ease-in-out infinite alternate;
}
@keyframes iconSpin { from{transform:scale(1) rotate(-8deg)} to{transform:scale(1.1) rotate(8deg)} }
#modal-title{font-family:var(--font);font-size:1.8rem;font-weight:900;color:var(--ink);margin-bottom:6px}
#modal-sub  {font-family:var(--font);font-size:1rem;font-weight:700;color:#999;margin-bottom:22px}
#modal-btn  {
  background:var(--ink);color:white;border:none;border-radius:50px;
  font-family:var(--font);font-size:1rem;font-weight:900;
  padding:12px 34px;cursor:pointer;
  transition:transform .1s;
}
#modal-btn:active{transform:translateY(3px)}

@keyframes fadeIn{from{opacity:0}to{opacity:1}}

/* ══════════════════════════════════════════════════
   RESPONSIVE
   ══════════════════════════════════════════════════ */
@media(max-height:720px){
  .eye{width:58px;height:58px} .pupil{width:23px;height:23px}
  .brow{width:27px;height:6px}
  #eyes{gap:32px}
  .eye-unit{gap:5px}
  #smile{width:30px;height:16px}
  #problem-card{padding:4px 0 8px}
  #num-a,#num-b{font-size:clamp(2.8rem,10vw,3.6rem)}
  #ans-mark{font-size:clamp(2.8rem,10vw,3.6rem)}
  .recognized-num{width:60px;height:60px;font-size:1.9rem}
}
@media(max-height:620px){
  .eye{width:48px;height:48px}
  #eyes{gap:26px}
  #smile{display:none}
}


#diff-section.hidden { display: none; }

/* モンスター王冠・マント */
#monster-crown {
  display: none;
  position: absolute;
  top: 4px;
  left: 50%;
  transform: translateX(-50%);
  width: 38px;
  height: 26px;
  background: #FFD93D;
  clip-path: polygon(0% 100%, 0% 45%, 25% 68%, 50% 0%, 75% 68%, 100% 45%, 100% 100%);
  pointer-events: none;
}
#monster-cape {
  display: none;
  width: 84px;
  height: 32px;
  background: var(--theme-dk);
  transition: background .5s;
  clip-path: polygon(8% 0%, 92% 0%, 100% 100%, 0% 100%);
  border-radius: 0 0 14px 14px;
  pointer-events: none;
}

/* モンスター成長クラス（累積: mon-s1 + mon-s2 + ... が全て付与される） */
#app.mon-s2 .ant-ball { transform: scale(1.5); }
#app.mon-s3 .brow     { height: 10px; }
#app.mon-s4 .eye::after {
  content: '';
  position: absolute;
  inset: 7px;
  border-radius: 50%;
  border: 3px solid rgba(255,215,61,.65);
  pointer-events: none;
}
#app.mon-s5 #monster-crown { display: block; }
#app.mon-s6 #monster-crown { background: linear-gradient(135deg,#FFD93D,#FF6B8A,#A29BFE,#4ECDC4); }
#app.mon-s7 #monster-cape  { display: block; }
#app.mon-s8 #character     { animation: rainbowGlow 3s linear infinite; }
@keyframes rainbowGlow {
  0%   { filter: hue-rotate(0deg)   brightness(1.06); }
  50%  { filter: hue-rotate(180deg) brightness(1.1);  }
  100% { filter: hue-rotate(360deg) brightness(1.06); }
}