:root {
  --bg-primary: #0a0a0f;
  --bg-secondary: #14141f;
  --bg-tertiary: #1e1e2e;
  --text-primary: #ffffff;
  --text-secondary: #a0a0b0;
  --text-muted: #606070;
  --accent: #00d4ff;
  --accent-secondary: #00ff88;
  --danger: #ff4466;
  --focus-ring: #00d4ff;
  --focus-glow: rgba(0, 212, 255, 0.4);
  --radius-md: 12px;
}
* { margin: 0; padding: 0; box-sizing: border-box; }
html, body {
  width: 600px; height: 600px; overflow: hidden;
  background: #000;
  color: var(--text-primary);
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
}
#app { width: 100%; height: 100%; position: relative; }
.screen { width: 100%; height: 100%; position: absolute; top: 0; left: 0; display: flex; flex-direction: column; }
.screen.hidden { display: none; }
.focusable { transition: all 0.15s ease; border: 2px solid transparent; cursor: pointer; outline: none; }
.focusable:focus { border-color: var(--focus-ring); box-shadow: 0 0 20px var(--focus-glow); }
.hidden { display: none !important; }

/* ---------- HOME ---------- */
.home-head { padding: 40px 36px 20px; }
.logo { display: flex; align-items: center; gap: 14px; }
.logo-wave {
  font-size: 46px; line-height: 1;
  color: var(--accent);
  text-shadow: 0 0 18px var(--focus-glow);
}
.home-head h1 { font-size: 40px; font-weight: 700; letter-spacing: -0.5px; }
.tagline { color: var(--text-secondary); font-size: 19px; margin-top: 8px; }
.home-streak { color: var(--accent-secondary); font-size: 16px; margin-top: 6px; font-weight: 600; }

.menu { flex: 1; display: flex; flex-direction: column; gap: 12px; padding: 8px 28px 28px; }
.menu-item {
  display: flex; flex-direction: column; justify-content: center; gap: 4px;
  text-align: left;
  background: var(--bg-secondary);
  color: var(--text-primary);
  border-radius: var(--radius-md);
  padding: 16px 22px;
  min-height: 88px;
}
.menu-item.primary {
  background: linear-gradient(135deg, #0a2e3a, #0a1f2e);
  border-color: rgba(0,212,255,0.25);
}
.mi-title { font-size: 24px; font-weight: 600; }
.menu-item.primary .mi-title { color: var(--accent); }
.mi-sub { font-size: 15px; color: var(--text-secondary); }

/* ---------- GAME ---------- */
.game-top {
  display: flex; align-items: center; gap: 10px;
  padding: 16px 22px;
  background: var(--bg-primary);
  border-bottom: 1px solid var(--bg-tertiary);
}
.stat {
  display: flex; align-items: center; gap: 7px;
  font-size: 22px; font-weight: 700;
  background: var(--bg-secondary);
  padding: 8px 14px; border-radius: 10px;
}
.stat-ico { font-size: 18px; }
.stat:nth-child(1) { color: var(--accent-secondary); }
.stat .mode, .stat.mode { margin-left: auto; }
.stat.mode {
  font-size: 16px; font-weight: 600;
  color: var(--text-secondary);
  text-transform: uppercase; letter-spacing: 1px;
}
.prompt {
  text-align: center; font-size: 26px; font-weight: 600;
  padding: 18px 20px 10px;
}
.replay {
  align-self: center;
  display: flex; align-items: center; gap: 10px;
  background: var(--bg-tertiary);
  color: var(--text-primary);
  font-size: 21px; font-weight: 600;
  padding: 14px 30px; border-radius: 999px;
  min-height: 56px;
  margin-bottom: 14px;
}
.replay-ico { font-size: 22px; }
.replay.playing { border-color: var(--accent); box-shadow: 0 0 24px var(--focus-glow); }

.note-grid {
  flex: 1;
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 10px;
  padding: 0 22px;
  align-content: start;
}
.note-btn {
  display: flex; align-items: center; justify-content: center;
  background: var(--bg-secondary);
  color: var(--text-primary);
  font-size: 28px; font-weight: 700;
  border-radius: var(--radius-md);
  min-height: 76px;
}
.note-btn.accidental {
  background: #0d0d16;
  color: var(--text-secondary);
}
.note-btn .sharp { font-size: 20px; opacity: 0.8; }
.note-btn.mark-correct {
  background: #0c3d28; color: var(--accent-secondary);
  border-color: var(--accent-secondary);
  box-shadow: 0 0 22px rgba(0,255,136,0.35);
}
.note-btn.mark-wrong {
  background: #3d0c1a; color: var(--danger);
  border-color: var(--danger);
}

.feedback {
  height: 56px;
  display: flex; align-items: center; justify-content: center;
  font-size: 22px; font-weight: 700;
  margin: 8px 22px 16px;
  border-radius: 10px;
  color: var(--text-muted);
}
.feedback.good { background: rgba(0,255,136,0.12); color: var(--accent-secondary); }
.feedback.bad { background: rgba(255,68,102,0.12); color: var(--danger); }

/* ---------- SUB SCREENS ---------- */
.sub-head {
  padding: 28px 32px 10px;
  border-bottom: 1px solid var(--bg-tertiary);
}
.sub-head h2 { font-size: 32px; font-weight: 700; }
.sub-body {
  flex: 1; display: flex; flex-direction: column; gap: 14px;
  padding: 24px 32px 28px;
}
.opt-row {
  display: flex; align-items: center; justify-content: space-between;
  background: var(--bg-secondary);
  color: var(--text-primary);
  border-radius: var(--radius-md);
  padding: 18px 24px; min-height: 88px;
}
.opt-label { font-size: 22px; font-weight: 600; }
.opt-val {
  font-size: 22px; font-weight: 700; color: var(--accent);
}
.opt-hint { color: var(--text-secondary); font-size: 16px; line-height: 1.5; padding: 4px 4px; }

.stat-grid {
  display: grid; grid-template-columns: 1fr 1fr; gap: 14px;
}
.stat-card {
  background: var(--bg-secondary);
  border-radius: var(--radius-md);
  padding: 22px; text-align: center;
}
.sc-num { font-size: 42px; font-weight: 800; color: var(--accent); }
.sc-lbl { font-size: 16px; color: var(--text-secondary); margin-top: 6px; }

.howto-body { gap: 18px; }
.howto-list { list-style: none; display: flex; flex-direction: column; gap: 14px; }
.howto-list li {
  font-size: 19px; line-height: 1.4; color: var(--text-secondary);
  background: var(--bg-secondary);
  padding: 14px 18px; border-radius: 10px;
}
.howto-list b { color: var(--text-primary); }

.btn-back, .btn-danger {
  margin-top: auto;
  background: var(--bg-tertiary);
  color: var(--text-primary);
  font-size: 22px; font-weight: 600;
  border-radius: var(--radius-md);
  padding: 18px; min-height: 64px;
  text-align: center;
}
.btn-danger { color: var(--danger); margin-top: 8px; }