:root {
  --bg1: #2e1065;
  --bg2: #4c1d95;
  --bg3: #6d28d9;
  --accent: #fbbf24;
  --accent2: #f472b6;
  --good: #34d399;
  --bad: #fb7185;
  --card: rgba(255, 255, 255, 0.08);
  --card-solid: #ffffff;
  --ink: #ffffff;
  --shadow: 0 10px 30px rgba(0, 0, 0, 0.35);
  --font: system-ui, -apple-system, "Segoe UI", Roboto, "Helvetica Neue", sans-serif;
}

* { box-sizing: border-box; margin: 0; padding: 0; -webkit-tap-highlight-color: transparent; }

html, body { height: 100%; }

body {
  font-family: var(--font);
  color: var(--ink);
  background: linear-gradient(160deg, var(--bg1), var(--bg2) 55%, var(--bg3));
  min-height: 100dvh;
  overflow-x: hidden;
  user-select: none;
  padding: env(safe-area-inset-top) env(safe-area-inset-right) env(safe-area-inset-bottom) env(safe-area-inset-left);
}

/* twinkling star field */
.stars-bg {
  position: fixed; inset: 0; z-index: 0; pointer-events: none;
  background-image:
    radial-gradient(2px 2px at 20% 30%, #fff, transparent),
    radial-gradient(2px 2px at 70% 20%, #fff, transparent),
    radial-gradient(1px 1px at 40% 70%, #fff, transparent),
    radial-gradient(2px 2px at 85% 60%, #fde68a, transparent),
    radial-gradient(1px 1px at 15% 80%, #fff, transparent),
    radial-gradient(1.5px 1.5px at 55% 45%, #fff, transparent),
    radial-gradient(2px 2px at 90% 90%, #f9a8d4, transparent),
    radial-gradient(1px 1px at 30% 15%, #fff, transparent);
  opacity: 0.7;
  animation: twinkle 4s ease-in-out infinite alternate;
}
@keyframes twinkle { from { opacity: 0.35; } to { opacity: 0.8; } }

/* ---------- screens ---------- */
.screen {
  position: relative; z-index: 1;
  display: none;
  flex-direction: column;
  min-height: 100dvh;
  padding: 20px 18px 28px;
  max-width: 560px;
  margin: 0 auto;
  animation: fadein 0.35s ease;
}
.screen.active { display: flex; }
@keyframes fadein { from { opacity: 0; transform: translateY(8px); } to { opacity: 1; transform: none; } }

/* ---------- HOME ---------- */
.home-inner { margin: auto 0; text-align: center; display: flex; flex-direction: column; align-items: center; gap: 10px; }
.badge {
  background: var(--accent); color: #7c2d12; font-weight: 800;
  padding: 6px 16px; border-radius: 999px; font-size: 0.9rem; letter-spacing: 0.3px;
  box-shadow: var(--shadow); transform: rotate(-3deg);
}
.hero-name {
  font-size: clamp(3.2rem, 18vw, 5.5rem); line-height: 1;
  background: linear-gradient(180deg, #fff, var(--accent));
  -webkit-background-clip: text; background-clip: text; color: transparent;
  text-shadow: 0 6px 24px rgba(251, 191, 36, 0.35); letter-spacing: 1px;
}
.hero-sub { font-size: 1.15rem; font-weight: 700; opacity: 0.92; margin-bottom: 12px; }

.menu { display: grid; grid-template-columns: 1fr 1fr; gap: 14px; width: 100%; margin-top: 6px; }
.menu-card {
  border: none; border-radius: 22px; padding: 22px 12px; cursor: pointer;
  display: flex; flex-direction: column; align-items: center; gap: 4px;
  color: #fff; font-family: var(--font); box-shadow: var(--shadow);
  transition: transform 0.12s ease, filter 0.12s ease;
}
.menu-card:active { transform: scale(0.95); filter: brightness(1.08); }
.menu-card.memorize { background: linear-gradient(160deg, #38bdf8, #2563eb); }
.menu-card.practice { background: linear-gradient(160deg, #fb7185, #db2777); }
.menu-emoji { font-size: 2.6rem; }
.menu-title { font-size: 1.35rem; font-weight: 800; }
.menu-desc { font-size: 0.82rem; opacity: 0.9; }

.home-stats { display: flex; gap: 10px; flex-wrap: wrap; justify-content: center; margin-top: 16px; min-height: 20px; }
.home-stat {
  background: var(--card); border: 1px solid rgba(255,255,255,0.15);
  border-radius: 14px; padding: 8px 14px; font-size: 0.85rem; font-weight: 700;
  backdrop-filter: blur(6px);
}
.home-stat b { font-size: 1.1rem; color: var(--accent); display: block; }

.install-btn {
  margin-top: 18px; background: rgba(255,255,255,0.14); color: #fff; border: 1px solid rgba(255,255,255,0.25);
  padding: 12px 20px; border-radius: 14px; font-weight: 700; font-size: 0.95rem; cursor: pointer;
}
.install-btn:active { transform: scale(0.96); }
.signature { margin-top: 22px; font-size: 0.85rem; opacity: 0.75; font-style: italic; }

/* ---------- topbar ---------- */
.topbar { display: flex; align-items: center; justify-content: space-between; gap: 10px; margin-bottom: 16px; }
.topbar h2 { font-size: 1.3rem; }
.topbar-spacer { width: 64px; }
.back-btn {
  background: rgba(255,255,255,0.12); border: 1px solid rgba(255,255,255,0.2); color: #fff;
  padding: 9px 14px; border-radius: 12px; font-weight: 700; font-size: 0.9rem; cursor: pointer; font-family: var(--font);
}
.back-btn:active { transform: scale(0.95); }
.back-btn.center { align-self: center; margin-top: 10px; }

/* ---------- pickers ---------- */
.pick-label { font-weight: 700; margin: 4px 0 10px; opacity: 0.92; }
.table-picker { display: grid; grid-template-columns: repeat(4, 1fr); gap: 10px; }
.tnum {
  aspect-ratio: 1; border: none; border-radius: 16px; cursor: pointer; font-family: var(--font);
  font-size: 1.5rem; font-weight: 800; color: #fff;
  background: linear-gradient(160deg, #7c3aed, #4c1d95);
  box-shadow: var(--shadow); position: relative; transition: transform 0.1s ease;
}
.tnum:active { transform: scale(0.92); }
.tnum.active { background: linear-gradient(160deg, var(--accent), #f59e0b); color: #7c2d12; outline: 3px solid #fff; }
.tnum .star-tag { position: absolute; top: 4px; right: 6px; font-size: 0.7rem; }

.picker-actions { display: flex; gap: 10px; margin: 12px 0 4px; }
.mini-btn {
  flex: 1; background: rgba(255,255,255,0.12); border: 1px solid rgba(255,255,255,0.2); color: #fff;
  padding: 10px; border-radius: 12px; font-weight: 700; cursor: pointer; font-family: var(--font);
}
.mini-btn:active { transform: scale(0.96); }

.count-picker { display: flex; gap: 10px; }
.count-btn {
  flex: 1; background: rgba(255,255,255,0.1); border: 2px solid rgba(255,255,255,0.18); color: #fff;
  padding: 14px; border-radius: 14px; font-weight: 800; font-size: 1.2rem; cursor: pointer; font-family: var(--font);
}
.count-btn.active { background: var(--accent); color: #7c2d12; border-color: #fff; }
.count-btn:active { transform: scale(0.96); }

.big-start {
  margin-top: auto; background: linear-gradient(160deg, var(--good), #059669); color: #fff; border: none;
  padding: 18px; border-radius: 18px; font-size: 1.35rem; font-weight: 800; cursor: pointer;
  box-shadow: var(--shadow); font-family: var(--font);
}
.big-start:active { transform: scale(0.97); }
.big-start:disabled { filter: grayscale(0.7) brightness(0.7); cursor: not-allowed; }

/* ---------- memorize table display ---------- */
.table-display { display: grid; gap: 10px; margin-top: 20px; }
.trow {
  display: grid; grid-template-columns: 1fr auto 1fr; align-items: center;
  background: var(--card); border: 1px solid rgba(255,255,255,0.14); border-radius: 14px;
  padding: 12px 16px; font-size: 1.25rem; font-weight: 700; backdrop-filter: blur(6px);
  animation: pop 0.3s ease backwards;
}
.trow .eq { text-align: left; }
.trow .res { text-align: right; color: var(--accent); font-size: 1.5rem; font-weight: 800; }
.trow .op { opacity: 0.6; padding: 0 10px; }
@keyframes pop { from { opacity: 0; transform: translateX(-10px); } to { opacity: 1; transform: none; } }
.memo-hint { text-align: center; opacity: 0.7; margin-top: 26px; font-size: 2rem; }

/* ---------- quiz ---------- */
.quiz-stats { display: flex; gap: 8px; }
.chip {
  background: rgba(255,255,255,0.14); border: 1px solid rgba(255,255,255,0.2);
  padding: 8px 12px; border-radius: 12px; font-weight: 800; font-size: 0.95rem;
}
.progress-track { height: 10px; background: rgba(255,255,255,0.14); border-radius: 999px; overflow: hidden; margin-bottom: 10px; }
.progress-fill { height: 100%; width: 0; background: linear-gradient(90deg, var(--accent), var(--accent2)); border-radius: 999px; transition: width 0.3s ease; }

.question-area { flex: 1; display: flex; flex-direction: column; align-items: center; justify-content: center; gap: 14px; }
.question { font-size: clamp(3rem, 15vw, 4.5rem); font-weight: 800; letter-spacing: 2px; }
.answer-box {
  min-width: 160px; text-align: center; font-size: 3rem; font-weight: 800; color: var(--accent);
  background: rgba(0,0,0,0.22); border-radius: 18px; padding: 8px 24px; border: 3px dashed rgba(255,255,255,0.25);
}
.answer-box.filled { border-style: solid; }
.feedback { font-size: 1.4rem; font-weight: 800; min-height: 34px; }
.feedback.good { color: var(--good); }
.feedback.bad { color: var(--bad); }

.answer-box.correct { animation: correct 0.5s ease; border-color: var(--good); color: var(--good); }
.answer-box.wrong { animation: shake 0.4s ease; border-color: var(--bad); color: var(--bad); }
@keyframes correct { 0%,100% { transform: scale(1); } 40% { transform: scale(1.18); } }
@keyframes shake { 0%,100% { transform: translateX(0); } 20% { transform: translateX(-10px); } 40% { transform: translateX(10px); } 60% { transform: translateX(-8px); } 80% { transform: translateX(8px); } }

.keypad { display: grid; grid-template-columns: repeat(3, 1fr); gap: 12px; margin-top: 18px; }
.key {
  padding: 20px 0; border: none; border-radius: 16px; font-size: 1.8rem; font-weight: 800; cursor: pointer;
  background: rgba(255,255,255,0.12); color: #fff; font-family: var(--font); box-shadow: var(--shadow);
  transition: transform 0.08s ease, background 0.1s ease;
}
.key:active { transform: scale(0.92); background: rgba(255,255,255,0.22); }
.key-clear { background: linear-gradient(160deg, #fb7185, #e11d48); }
.key-enter { background: linear-gradient(160deg, var(--good), #059669); }

/* ---------- results ---------- */
.results-inner { margin: auto 0; text-align: center; display: flex; flex-direction: column; align-items: center; gap: 14px; }
.results-emoji { font-size: 5rem; animation: bounce 1s ease infinite; }
@keyframes bounce { 0%,100% { transform: translateY(0); } 50% { transform: translateY(-14px); } }
#results-title { font-size: 2rem; }
.results-stats { display: flex; gap: 12px; margin: 8px 0; }
.rstat {
  background: var(--card); border: 1px solid rgba(255,255,255,0.15); border-radius: 16px;
  padding: 16px 18px; min-width: 88px; backdrop-filter: blur(6px);
}
.rstat-num { display: block; font-size: 1.9rem; font-weight: 800; color: var(--accent); }
.rstat-label { font-size: 0.8rem; opacity: 0.85; }
.results-stars { font-size: 2.4rem; letter-spacing: 4px; min-height: 40px; }
.results-inner .big-start { margin-top: 10px; width: 100%; max-width: 320px; }

/* confetti */
.confetti { position: fixed; top: -20px; width: 12px; height: 12px; z-index: 50; pointer-events: none; border-radius: 2px; }
@keyframes fall { to { transform: translateY(105vh) rotate(720deg); opacity: 0.9; } }