* { box-sizing: border-box; margin: 0; padding: 0; }

:root {
  --primary: #fd79a8;
  --accent:  #6c5ce7;
  --text:    #2d3436;
  --muted:   #636e72;
  --shadow:    0 8px 24px rgba(253, 121, 168, 0.18);
  --shadow-lg: 0 16px 48px rgba(253, 121, 168, 0.28);
}

html, body { height: 100%; }

body {
  font-family: 'Fredoka', system-ui, -apple-system, Segoe UI, sans-serif;
  background:
    radial-gradient(circle at 10% 20%, #ffe5f1 0%, transparent 40%),
    radial-gradient(circle at 90% 30%, #e0f4ff 0%, transparent 40%),
    radial-gradient(circle at 50% 90%, #fff4cc 0%, transparent 40%),
    linear-gradient(135deg, #fdf2f8, #f0f9ff);
  background-attachment: fixed;
  min-height: 100vh; min-height: 100dvh;
  color: var(--text);
  -webkit-font-smoothing: antialiased;
  -webkit-tap-highlight-color: transparent;
  overscroll-behavior-y: contain;
}

button { font-family: inherit; touch-action: manipulation; }
a { color: inherit; text-decoration: none; }

#app {
  max-width: 900px; margin: 0 auto;
  padding-top:    max(24px, env(safe-area-inset-top));
  padding-bottom: max(48px, env(safe-area-inset-bottom));
  padding-left:   max(16px, env(safe-area-inset-left));
  padding-right:  max(16px, env(safe-area-inset-right));
}

.screen { display: none; animation: fadeIn 0.35s ease; }
.screen.active { display: block; }
@keyframes fadeIn { from{opacity:0;transform:translateY(8px);} to{opacity:1;transform:translateY(0);} }

/* ============== Навигация по детским модулям ============== */
.kids-nav {
  display: flex;
  gap: 8px;
  margin-bottom: 24px;
  overflow-x: auto;
  padding: 4px 2px;
  -webkit-overflow-scrolling: touch;
  scrollbar-width: none;
}
.kids-nav::-webkit-scrollbar { display: none; }
.kids-nav__chip {
  flex-shrink: 0;
  padding: 8px 16px;
  background: white;
  border-radius: 22px;
  text-decoration: none;
  color: var(--text);
  font-size: 0.95rem;
  font-weight: 500;
  box-shadow: var(--shadow);
  white-space: nowrap;
  transition: transform 0.2s;
}
.kids-nav__chip:active { transform: scale(0.95); }
.kids-nav__chip--active {
  background: linear-gradient(135deg, var(--primary), var(--accent));
  color: white;
  pointer-events: none;
}
.kids-nav__chip--hub { padding: 8px 12px; }

.home-header { text-align: center; margin-bottom: 32px; }
.home-header h1 {
  font-size: clamp(2rem, 5vw, 3rem); font-weight: 700;
  background: linear-gradient(135deg, var(--primary), var(--accent));
  -webkit-background-clip: text; background-clip: text; -webkit-text-fill-color: transparent;
  margin-bottom: 8px;
}
.subtitle { color: var(--muted); font-size: 1rem; margin-bottom: 20px; }

/* Режим-карточки */
.mode-cards {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 18px;
  margin-bottom: 32px;
}
.mode-card {
  border: none; cursor: pointer;
  background: white;
  border-radius: 24px;
  padding: 32px 24px;
  text-align: center;
  box-shadow: var(--shadow);
  transition: transform 0.2s, box-shadow 0.2s;
  font-family: inherit;
  color: var(--text);
}
.mode-card:active { transform: scale(0.97); }
.mode-card .mode-emoji { font-size: 3rem; margin-bottom: 8px; }
.mode-card h3 { font-size: 1.4rem; margin-bottom: 6px; }
.mode-card p  { color: var(--muted); font-size: 1rem; }

.mode-card--add { border-top: 6px solid #1dd1a1; }
.mode-card--sub { border-top: 6px solid #ff6b6b; }
.mode-card--mix { border-top: 6px solid #6c5ce7; }

.cta-row { display: flex; gap: 12px; justify-content: center; flex-wrap: wrap; }
.cta-btn {
  font-size: 1.05rem; font-weight: 600; padding: 12px 22px;
  border-radius: 14px; border: none; cursor: pointer;
  background: linear-gradient(135deg, var(--primary), var(--accent));
  color: white; box-shadow: var(--shadow);
  display: inline-block; text-align: center;
}
.cta-btn.ghost { background: white; color: var(--text); }

.back-btn {
  font-size: 1rem; font-weight: 500; padding: 10px 18px;
  border-radius: 12px; border: none; cursor: pointer;
  background: white; color: var(--text); box-shadow: var(--shadow);
  margin-bottom: 24px;
}

/* Игра */
.game-header { text-align: center; margin-bottom: 28px; }
.game-header h2 {
  font-size: 2rem; font-weight: 700;
  background: linear-gradient(135deg, var(--primary), var(--accent));
  -webkit-background-clip: text; background-clip: text; -webkit-text-fill-color: transparent;
  margin-bottom: 8px;
}
.game-stats { font-size: 1rem; color: var(--muted); }

.problem {
  background: white;
  border-radius: 28px;
  padding: 32px 24px;
  text-align: center;
  box-shadow: var(--shadow-lg);
  margin-bottom: 28px;
}

.problem-visual {
  font-size: clamp(2rem, 5vw, 3rem);
  margin-bottom: 16px;
  min-height: 80px;
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  align-items: center;
  gap: 6px;
  line-height: 1;
}
.problem-visual .group {
  display: inline-flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 4px;
  padding: 8px 12px;
  background: rgba(0, 0, 0, 0.03);
  border-radius: 16px;
}
.problem-visual .group.minus {
  position: relative;
}
.problem-visual .group .crossed {
  position: relative;
  opacity: 0.3;
}
.problem-visual .group .crossed::after {
  content: '✕';
  position: absolute;
  inset: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.5em;
  color: #ff6b6b;
  opacity: 1;
}
.problem-visual .op {
  font-size: 1.5em;
  font-weight: 700;
  color: var(--muted);
  margin: 0 4px;
}

.problem-text {
  font-size: clamp(2.5rem, 7vw, 4rem);
  font-weight: 700;
  color: var(--text);
  letter-spacing: 0.02em;
}
.problem-text .answer-slot { color: var(--primary); }

.game-options {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 12px;
  max-width: 600px;
  margin: 0 auto;
}
.game-option {
  aspect-ratio: 1; border-radius: 22px; background: white;
  font-size: 2.6rem; font-weight: 700; border: none; cursor: pointer;
  box-shadow: var(--shadow); transition: all 0.2s;
  color: var(--primary); font-family: inherit;
}
.game-option:active { transform: scale(0.96); }
.game-option:disabled { cursor: default; }
.game-option.correct { background: #55efc4; color: white; animation: pop 0.45s ease; }
.game-option.wrong   { background: #ff7675; color: white; animation: shake 0.4s ease; }
@keyframes pop   { 0%,100%{transform:scale(1);} 50%{transform:scale(1.18);} }
@keyframes shake { 0%,100%{transform:translateX(0);} 25%{transform:translateX(-10px);} 75%{transform:translateX(10px);} }

.game-result {
  text-align: center; margin-top: 24px;
  font-size: 1.4rem; font-weight: 600; min-height: 2em; color: var(--text);
}
.game-final { padding: 32px 20px; }
.game-final .emoji-final { font-size: 5rem; margin-bottom: 12px; }
.game-final h3 { font-size: 1.8rem; margin-bottom: 12px; }
.game-final__buttons { display: flex; gap: 12px; justify-content: center; flex-wrap: wrap; margin-top: 16px; }

@media (hover: hover) and (pointer: fine) {
  .mode-card:hover { transform: translateY(-4px) scale(1.02); box-shadow: var(--shadow-lg); }
  .cta-btn:hover   { transform: translateY(-2px); box-shadow: var(--shadow-lg); }
  .back-btn:hover  { transform: translateX(-3px); }
  .game-option:hover { transform: translateY(-4px); box-shadow: var(--shadow-lg); }
}

@media (max-width: 480px) {
  .mode-card { padding: 24px 16px; }
  .game-options { grid-template-columns: repeat(2, 1fr); gap: 12px; }
  .game-option { font-size: 2.2rem; }
  .problem { padding: 24px 16px; }
}

/* ============== Feedback panel (после ответа) ============== */
.feedback-msg {
  font-size: clamp(1.05rem, 2.6vw, 1.3rem);
  font-weight: 500;
  margin-bottom: 14px;
  color: var(--text);
}
.feedback-correct {
  font-weight: 700;
  color: var(--primary);
}
.feedback-buttons {
  display: flex;
  gap: 12px;
  justify-content: center;
  flex-wrap: wrap;
}
.feedback-btn {
  font-size: 1.05rem;
  font-weight: 600;
  padding: 14px 28px;
  border-radius: 16px;
  border: none;
  cursor: pointer;
  background: linear-gradient(135deg, var(--primary), var(--accent));
  color: white;
  box-shadow: var(--shadow);
  font-family: inherit;
  transition: transform 0.15s, box-shadow 0.15s;
}
.feedback-btn:active { transform: scale(0.96); }
.feedback-btn--ghost {
  background: white;
  color: var(--text);
}
@media (hover: hover) and (pointer: fine) {
  .feedback-btn:hover { transform: translateY(-2px); }
}

/* ============== Difficulty selector ============== */
.difficulty {
  margin-bottom: 28px;
  text-align: center;
}
.difficulty__label {
  font-size: 0.95rem;
  color: var(--muted);
  margin-bottom: 10px;
  font-weight: 500;
}
.difficulty__buttons {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(140px, 1fr));
  gap: 12px;
  max-width: 800px;
  margin: 0 auto;
}
.diff-btn {
  background: white;
  border: 2px solid transparent;
  border-radius: 18px;
  padding: 14px 12px;
  cursor: pointer;
  font-family: inherit;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 4px;
  box-shadow: var(--shadow);
  transition: transform 0.15s, border-color 0.15s, box-shadow 0.15s;
}
.diff-btn:active { transform: scale(0.97); }
.diff-icon { font-size: 1.8rem; }
.diff-name { font-weight: 700; color: var(--text); }
.diff-hint { font-size: 0.8rem; color: var(--muted); }

.diff-btn--active {
  border-color: var(--primary);
  background: linear-gradient(135deg, rgba(253, 121, 168, 0.1), rgba(108, 92, 231, 0.08));
  box-shadow: var(--shadow-lg);
}
@media (hover: hover) and (pointer: fine) {
  .diff-btn:hover { transform: translateY(-3px); border-color: var(--primary); }
}