:root {
  --primary: #4f46e5;
  --primary-hover: #4338ca;
  --success: #10b981;
  --danger: #ef4444;
  --warning: #f59e0b;
  --bg: #0f172a;
  --card-bg: #1e293b;
  --card-hover: #334155;
  --border: #334155;
  --text-main: #f8fafc;
  --text-muted: #94a3b8;
  --font-family: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
}

* { box-sizing: border-box; margin: 0; padding: 0; }
body {
  font-family: var(--font-family);
  background: var(--bg);
  color: var(--text-main);
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

/* NAGŁÓWEK */
.app-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 1rem 1.5rem;
  background: rgba(30, 41, 59, 0.85);
  backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--border);
  position: sticky;
  top: 0;
  z-index: 100;
}
.header-left { display: flex; align-items: center; gap: 0.75rem; }
.logo-icon { font-size: 1.8rem; }
.logo-text { font-size: 1.25rem; font-weight: 800; letter-spacing: -0.02em; }
.header-right { display: flex; align-items: center; gap: 0.75rem; }

.user-badge {
  background: #1e1b4b;
  border: 1px solid #4338ca;
  color: #c7d2fe;
  padding: 0.35rem 0.75rem;
  border-radius: 20px;
  font-size: 0.85rem;
  font-weight: 700;
}

.pwa-install-badge {
  background: #3730a3;
  color: #fff;
  border: 1px solid #6366f1;
  border-radius: 50%;
  width: 36px;
  height: 36px;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1rem;
}

.icon-btn {
  background: var(--card-bg);
  border: 1px solid var(--border);
  color: var(--text-main);
  width: 40px;
  height: 40px;
  border-radius: 10px;
  cursor: pointer;
  font-size: 1.1rem;
  transition: all 0.2s;
}
.icon-btn:hover { background: var(--card-hover); }

.global-stars {
  display: flex;
  align-items: center;
  gap: 0.4rem;
  background: #28200d;
  border: 1px solid #78350f;
  padding: 0.4rem 0.8rem;
  border-radius: 20px;
  font-weight: 700;
  color: #fde047;
}

/* KONTENER */
.app-container {
  max-width: 900px;
  width: 100%;
  margin: 0 auto;
  padding: 1.5rem;
  flex: 1;
}

.screen-view { display: none; animation: fadeIn 0.25s ease-out; }
.screen-view.active { display: block; }
@keyframes fadeIn { from { opacity: 0; transform: translateY(6px); } to { opacity: 1; transform: translateY(0); } }

.screen-title-group { text-align: center; margin-bottom: 2rem; }
.step-badge {
  display: inline-block;
  background: #3730a3;
  color: #c7d2fe;
  font-size: 0.75rem;
  font-weight: 700;
  padding: 0.25rem 0.75rem;
  border-radius: 9999px;
  margin-bottom: 0.5rem;
}
.screen-title-group h2 { font-size: 1.8rem; font-weight: 800; margin-bottom: 0.3rem; }
.screen-title-group p { color: var(--text-muted); font-size: 0.95rem; }

.screen-nav {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 1.5rem;
  flex-wrap: wrap;
  gap: 0.5rem;
}
.nav-back-btn, .nav-back-btn-sm {
  background: transparent;
  border: 1px solid var(--border);
  color: var(--text-muted);
  padding: 0.5rem 1rem;
  border-radius: 8px;
  cursor: pointer;
  font-weight: 600;
  transition: all 0.2s;
}
.nav-back-btn:hover, .nav-back-btn-sm:hover { background: var(--card-bg); color: var(--text-main); }

.selected-op-tag {
  background: #312e81;
  color: #e0e7ff;
  padding: 0.4rem 0.9rem;
  border-radius: 20px;
  font-size: 0.85rem;
  font-weight: 600;
}

/* EKRAN WYBORU JĘZYKA */
.lang-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
  gap: 1.25rem;
  max-width: 600px;
  margin: 2rem auto;
}
.lang-card-btn {
  background: var(--card-bg);
  border: 2px solid var(--border);
  border-radius: 16px;
  padding: 1.5rem;
  text-align: center;
  color: var(--text-main);
  cursor: pointer;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.5rem;
  transition: all 0.2s;
}
.lang-card-btn:hover { transform: translateY(-4px); border-color: var(--primary); background: var(--card-hover); }
.lang-card-btn .flag-icon { font-size: 2.5rem; }
.lang-card-btn strong { font-size: 1.15rem; }
.lang-card-btn small { color: var(--text-muted); font-size: 0.8rem; }

/* BRAMKA AUTORYZACJI */
.auth-gate-card {
  background: var(--card-bg);
  border: 2px solid var(--border);
  border-radius: 20px;
  max-width: 440px;
  margin: 2rem auto;
  padding: 2.5rem 2rem;
  text-align: center;
  box-shadow: 0 10px 25px -5px rgba(0,0,0,0.4);
}
.subtitle-text { color: var(--text-muted); font-size: 0.95rem; margin-top: 0.3rem; }

.modal-tabs { display: flex; border-bottom: 2px solid var(--border); margin-bottom: 1.5rem; }
.modal-tab {
  flex: 1;
  background: transparent;
  border: none;
  color: var(--text-muted);
  padding: 0.6rem 0;
  font-weight: 700;
  font-size: 0.95rem;
  cursor: pointer;
  border-bottom: 2px solid transparent;
  margin-bottom: -2px;
}
.modal-tab.active { color: #818cf8; border-bottom-color: #818cf8; }

.auth-form { display: flex; flex-direction: column; gap: 1rem; }
.input-field { display: flex; flex-direction: column; gap: 0.3rem; text-align: left; }
.input-field label { font-size: 0.8rem; font-weight: 600; color: var(--text-muted); }
.input-field input {
  background: var(--bg);
  border: 1px solid var(--border);
  padding: 0.65rem 0.85rem;
  border-radius: 8px;
  color: var(--text-main);
  font-size: 0.95rem;
}
.input-field input:focus { outline: none; border-color: var(--primary); }

.auth-aux-links { text-align: right; }
.small-text-link { color: #818cf8; font-size: 0.8rem; text-decoration: none; font-weight: 600; }
.small-text-link:hover { text-decoration: underline; }

.auth-error-msg {
  background: #450a0a;
  border: 1px solid #b91c1c;
  color: #fca5a5;
  padding: 0.5rem;
  border-radius: 6px;
  font-size: 0.8rem;
}

.divider-text { position: relative; margin: 1.75rem 0 1.25rem; text-align: center; }
.divider-text::before { content: ""; position: absolute; top: 50%; left: 0; right: 0; height: 1px; background: var(--border); }
.divider-text span { position: relative; background: var(--card-bg); padding: 0 0.75rem; color: var(--text-muted); font-size: 0.8rem; font-weight: 700; }

.btn-guest {
  background: #334155;
  color: white;
  border: 1px solid #475569;
  padding: 0.85rem 1.5rem;
  border-radius: 10px;
  font-weight: 700;
  width: 100%;
  cursor: pointer;
  transition: all 0.2s;
}
.btn-guest:hover { background: #475569; }

/* MENU GŁÓWNE */
.menu-hero-card { max-width: 500px; margin: 2rem auto; text-align: center; }
.menu-greeting { margin-bottom: 2rem; }
.menu-greeting h2 { font-size: 2rem; font-weight: 800; margin-bottom: 0.3rem; }
.menu-greeting p { color: var(--text-muted); }

.menu-buttons-list { display: flex; flex-direction: column; gap: 1rem; }
.menu-action-btn {
  background: var(--card-bg);
  border: 2px solid var(--border);
  color: var(--text-main);
  padding: 1.1rem 1.5rem;
  border-radius: 14px;
  font-size: 1.15rem;
  font-weight: 700;
  cursor: pointer;
  display: flex;
  align-items: center;
  gap: 1rem;
  transition: all 0.2s;
}
.menu-action-btn:hover { transform: translateX(6px); border-color: var(--primary); background: var(--card-hover); }
.menu-action-btn.primary { background: #312e81; border-color: #4f46e5; color: #ffffff; }
.menu-action-btn.primary:hover { background: #3730a3; }
.menu-action-btn.danger { color: #fca5a5; border-color: #7f1d1d; background: #271418; }
.menu-action-btn.danger:hover { background: #3f1d24; }

/* STATYSTYKI & USTAWIENIA */
.stats-overview-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(200px, 1fr)); gap: 1.25rem; margin-top: 1.5rem; }
.stat-card { background: var(--card-bg); border: 2px solid var(--border); border-radius: 16px; padding: 2rem 1.5rem; text-align: center; }
.stat-big-val { font-size: 2.8rem; font-weight: 900; color: var(--warning); display: block; }
.stat-card-label { color: var(--text-muted); font-size: 0.95rem; font-weight: 600; }

.settings-box {
  background: var(--card-bg);
  border: 2px solid var(--border);
  border-radius: 16px;
  max-width: 500px;
  margin: 1.5rem auto;
  padding: 1.5rem;
  display: flex;
  flex-direction: column;
  gap: 1.25rem;
}
.setting-row { display: flex; justify-content: space-between; align-items: center; padding-bottom: 1rem; border-bottom: 1px solid var(--border); }
.setting-row:last-child { border-bottom: none; padding-bottom: 0; }
.lang-select { background: var(--card-bg); color: var(--text-main); border: 1px solid var(--border); padding: 0.35rem 0.5rem; border-radius: 8px; font-size: 0.85rem; font-weight: 600; cursor: pointer; outline: none; }

/* KROK 1: KAFELKI */
.operations-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(220px, 1fr)); gap: 1.25rem; }
.op-card {
  background: var(--card-bg);
  border: 2px solid var(--border);
  border-radius: 16px;
  padding: 1.75rem 1.25rem;
  text-align: center;
  cursor: pointer;
  transition: all 0.2s ease;
  user-select: none;
}
.op-card:hover { transform: translateY(-4px); border-color: var(--primary); background: var(--card-hover); }
.op-card .op-symbol { font-size: 3rem; display: block; margin-bottom: 0.5rem; }
.op-card h3 { font-size: 1.25rem; margin-bottom: 0.25rem; }
.op-card p { color: var(--text-muted); font-size: 0.85rem; }

/* KROK 2: TRUDNOŚĆ */
.difficulties-list { display: flex; flex-direction: column; gap: 1rem; }
.diff-card {
  background: var(--card-bg);
  border: 2px solid var(--border);
  border-radius: 14px;
  padding: 1.25rem 1.5rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
  cursor: pointer;
  transition: all 0.2s;
}
.diff-card:not(.locked):hover { transform: translateX(6px); border-color: var(--primary); }
.diff-card.locked { opacity: 0.6; cursor: not-allowed; filter: grayscale(0.8); border-style: dashed; }
.diff-info h3 { font-size: 1.15rem; }
.diff-info p { color: var(--text-muted); font-size: 0.85rem; margin-top: 0.2rem; }
.diff-lock-state { display: flex; flex-direction: column; align-items: flex-end; gap: 0.4rem; }
.lock-badge { font-size: 0.8rem; background: #3f1d24; color: #fca5a5; border: 1px solid #7f1d1d; padding: 0.3rem 0.6rem; border-radius: 6px; font-weight: 600; }
.unlocked-badge { font-size: 0.8rem; background: #064e3b; color: #6ee7b7; padding: 0.3rem 0.6rem; border-radius: 6px; font-weight: 600; }
.diff-progress-bar-bg { width: 140px; height: 6px; background: var(--border); border-radius: 3px; overflow: hidden; }
.diff-progress-bar-fill { height: 100%; background: var(--warning); }

/* KROK 3: ETAPY */
.stages-header-card {
  background: var(--card-bg);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 1.25rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 1rem;
  flex-wrap: wrap;
  gap: 1rem;
}
.quick-jump-box { display: flex; align-items: center; gap: 0.5rem; }
.quick-jump-box input { width: 70px; padding: 0.4rem; background: var(--bg); border: 1px solid var(--border); color: var(--text-main); border-radius: 6px; text-align: center; font-weight: 700; }

.pagination-bar { display: flex; justify-content: space-between; align-items: center; margin-bottom: 1rem; }
.page-nav-btn { background: var(--card-bg); border: 1px solid var(--border); color: var(--text-main); padding: 0.5rem 1rem; border-radius: 8px; cursor: pointer; font-weight: 600; }
.page-nav-btn:disabled { opacity: 0.3; cursor: not-allowed; }
.page-indicator { font-weight: 700; color: var(--text-muted); }

.stages-grid { display: grid; grid-template-columns: repeat(5, 1fr); gap: 0.75rem; }
@media (max-width: 600px) { .stages-grid { grid-template-columns: repeat(4, 1fr); } }

.stage-btn {
  background: var(--card-bg);
  border: 2px solid var(--border);
  border-radius: 12px;
  padding: 0.9rem 0.5rem;
  text-align: center;
  color: var(--text-main);
  cursor: pointer;
  transition: all 0.15s;
}
.stage-btn:not(.locked):hover { transform: translateY(-3px); border-color: var(--primary); background: var(--card-hover); }
.stage-btn.locked { opacity: 0.4; cursor: not-allowed; pointer-events: none; filter: grayscale(1); }
.stage-btn .stage-num { font-size: 1.1rem; font-weight: 800; display: block; }
.stage-btn .stage-stars { font-size: 0.75rem; margin-top: 0.25rem; display: block; }

/* ROZGRYWKA */
.game-top-bar { display: flex; justify-content: space-between; align-items: center; margin-bottom: 1rem; }
.game-meta { font-weight: 700; color: var(--text-muted); font-size: 0.95rem; }
.game-score-display { font-weight: 800; color: var(--warning); }

.progress-track { width: 100%; height: 8px; background: var(--card-bg); border-radius: 4px; overflow: hidden; margin-bottom: 0.75rem; }
.progress-fill { height: 100%; background: linear-gradient(90deg, var(--primary), #818cf8); transition: width 0.3s ease; }

.question-status-row { display: flex; justify-content: space-between; align-items: center; color: var(--text-muted); font-size: 0.9rem; margin-bottom: 1.5rem; }
.streak-badge { background: #451a03; color: #fdba74; border: 1px solid #9a3412; padding: 0.2rem 0.6rem; border-radius: 20px; font-weight: 800; }

.equation-card {
  background: var(--card-bg);
  border: 2px solid var(--border);
  border-radius: 20px;
  padding: 2.5rem 1rem;
  text-align: center;
  margin-bottom: 2rem;
  box-shadow: 0 10px 25px -5px rgba(0, 0, 0, 0.3);
}
.equation-text { font-size: 3.2rem; font-weight: 900; letter-spacing: 2px; }

.answers-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 1.25rem; }
@media (max-width: 500px) { .answers-grid { grid-template-columns: 1fr; } }

.answer-tile {
  background: var(--card-bg);
  border: 2px solid var(--border);
  color: var(--text-main);
  padding: 1.5rem;
  border-radius: 16px;
  font-size: 2rem;
  font-weight: 800;
  cursor: pointer;
  transition: transform 0.1s, border-color 0.2s, background-color 0.2s;
}
.answer-tile:hover { background: var(--card-hover); border-color: var(--primary); transform: translateY(-2px); }
.answer-tile.correct-pick { background: var(--success) !important; border-color: #34d399 !important; color: #ffffff !important; transform: scale(1.03); }
.answer-tile.wrong-pick { background: var(--danger) !important; border-color: #f87171 !important; color: #ffffff !important; animation: shake 0.35s ease; }
@keyframes shake { 0%, 100% { transform: translateX(0); } 25% { transform: translateX(-8px); } 75% { transform: translateX(8px); } }

/* PODSUMOWANIE */
.summary-card {
  background: var(--card-bg);
  border: 2px solid var(--border);
  border-radius: 24px;
  max-width: 520px;
  margin: 1.5rem auto;
  padding: 2.5rem 2rem;
  text-align: center;
}
.summary-icon { font-size: 3.5rem; margin-bottom: 0.5rem; }
.summary-subtitle { color: var(--text-muted); margin-bottom: 1.5rem; }
.diff-unlocked-banner { background: #422006; border: 2px solid var(--warning); color: #fef08a; padding: 0.9rem; border-radius: 12px; font-size: 0.9rem; margin-bottom: 1.5rem; }
.summary-stars { font-size: 2.5rem; letter-spacing: 0.3rem; margin-bottom: 1.5rem; }
.summary-stats-box { display: grid; grid-template-columns: repeat(3, 1fr); gap: 0.75rem; margin-bottom: 2rem; }
.stat-cell { background: var(--bg); padding: 0.8rem; border-radius: 10px; }
.stat-label { display: block; font-size: 0.75rem; color: var(--text-muted); margin-bottom: 0.25rem; }
.stat-val { font-size: 1.25rem; font-weight: 800; }
.summary-actions { display: flex; flex-direction: column; gap: 0.75rem; }

/* PRZYCISKI */
.btn-primary { background: var(--primary); color: white; border: none; padding: 0.85rem 1.5rem; border-radius: 10px; font-weight: 700; cursor: pointer; }
.btn-primary:hover { background: var(--primary-hover); }
.btn-primary-sm { background: var(--primary); color: white; border: none; padding: 0.4rem 0.8rem; border-radius: 6px; font-weight: 700; cursor: pointer; }
.btn-secondary { background: var(--card-hover); color: white; border: 1px solid var(--border); padding: 0.85rem 1.5rem; border-radius: 10px; font-weight: 700; cursor: pointer; }
.btn-secondary-sm { background: var(--card-hover); color: white; border: 1px solid var(--border); padding: 0.4rem 0.8rem; border-radius: 6px; font-weight: 600; cursor: pointer; }
.btn-outline { background: transparent; color: var(--text-muted); border: 1px solid var(--border); padding: 0.85rem 1.5rem; border-radius: 10px; font-weight: 600; cursor: pointer; }
.btn-danger-sm { background: #7f1d1d; color: #fca5a5; border: none; padding: 0.4rem 0.8rem; border-radius: 6px; cursor: pointer; font-weight: 700; }

/* REKLAMY REWARDED */
.rewarded-ad-actions { margin-top: 1rem; display: flex; flex-direction: column; gap: 0.75rem; }
.btn-rewarded {
  background: linear-gradient(135deg, #d97706, #b45309);
  color: #fff;
  border: 2px solid #f59e0b;
  padding: 0.9rem 1.25rem;
  border-radius: 12px;
  font-size: 1rem;
  font-weight: 800;
  cursor: pointer;
  box-shadow: 0 4px 15px rgba(217, 119, 6, 0.35);
  transition: transform 0.2s;
}
.btn-rewarded:hover { transform: translateY(-2px); }

.rewarded-modal-overlay {
  display: none;
  position: fixed;
  inset: 0;
  background: rgba(0, 0, 0, 0.92);
  z-index: 10000;
  justify-content: center;
  align-items: center;
  padding: 1.5rem;
}
.rewarded-modal-overlay.active { display: flex; }
.rewarded-modal-box { background: #1e293b; border: 2px solid #475569; border-radius: 20px; max-width: 460px; width: 100%; padding: 1.5rem; text-align: center; }
.rewarded-header { display: flex; justify-content: space-between; align-items: center; margin-bottom: 1.25rem; }
.ad-tag { background: #334155; color: #94a3b8; font-size: 0.75rem; font-weight: 800; padding: 0.25rem 0.6rem; border-radius: 6px; }
.countdown-badge { background: #0f172a; color: #f59e0b; border: 1px solid #78350f; padding: 0.3rem 0.75rem; border-radius: 20px; font-weight: 800; font-size: 0.85rem; }
.rewarded-video-placeholder { background: #0f172a; border-radius: 14px; padding: 3rem 1.5rem; margin-bottom: 1rem; display: flex; flex-direction: column; align-items: center; gap: 1rem; }
.play-icon-anim { width: 60px; height: 60px; background: #d97706; color: #fff; border-radius: 50%; display: flex; align-items: center; justify-content: center; font-size: 1.5rem; }
.ad-progress-track { width: 100%; height: 6px; background: #334155; border-radius: 3px; overflow: hidden; }
.ad-progress-fill { height: 100%; width: 0%; background: #f59e0b; transition: width 0.1s linear; }
.ad-hint { color: #64748b; font-size: 0.8rem; }

/* BANER RODO/COOKIES */
.cookie-banner {
  position: fixed;
  bottom: 1rem;
  left: 1rem;
  right: 1rem;
  max-width: 600px;
  margin: 0 auto;
  background: rgba(15, 23, 42, 0.95);
  border: 1px solid var(--primary);
  border-radius: 14px;
  padding: 1rem 1.25rem;
  box-shadow: 0 10px 25px rgba(0,0,0,0.5);
  z-index: 9999;
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
  backdrop-filter: blur(8px);
}
.cookie-banner p { font-size: 0.85rem; color: var(--text-muted); line-height: 1.4; }
.cookie-buttons { display: flex; gap: 0.5rem; justify-content: flex-end; }