/* =====================================================
   DPBT MASTER – Main Stylesheet
   Dark theme · Glassmorphism · Modern UI
   ===================================================== */

/* ---- Reset ---- */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { font-size: 16px; scroll-behavior: smooth; }
body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  background: var(--bg);
  color: var(--text);
  min-height: 100vh;
  overflow-x: hidden;
  line-height: 1.5;
}
button { cursor: pointer; font-family: inherit; border: none; outline: none; }
input { font-family: inherit; }
ul, ol { list-style: none; }

/* ---- CSS Variables ---- */
:root {
  --bg:           #0a0a1a;
  --bg2:          #111128;
  --bg3:          #1a1a35;
  --glass:        rgba(255,255,255,0.04);
  --glass-hover:  rgba(255,255,255,0.08);
  --border:       rgba(255,255,255,0.08);
  --border-hover: rgba(255,255,255,0.2);

  --text:         #e8e8ff;
  --text2:        #9090bb;
  --text3:        #5555aa;

  --purple:       #7c3aed;
  --purple-l:     #9d5cf0;
  --purple-d:     #5b21b6;
  --cyan:         #06b6d4;
  --cyan-l:       #22d3ee;
  --green:        #10b981;
  --green-l:      #34d399;
  --red:          #ef4444;
  --red-l:        #f87171;
  --yellow:       #f59e0b;
  --yellow-l:     #fbbf24;
  --orange:       #f97316;

  --grad:        linear-gradient(135deg, #7c3aed, #06b6d4);
  --grad-green:  linear-gradient(135deg, #059669, #10b981);
  --grad-red:    linear-gradient(135deg, #dc2626, #ef4444);
  --grad-gold:   linear-gradient(135deg, #d97706, #f59e0b);

  --radius:  14px;
  --radius-s: 8px;
  --radius-l: 20px;
  --radius-xl: 28px;

  --shadow:   0 8px 32px rgba(0,0,0,0.4);
  --shadow-l: 0 16px 64px rgba(0,0,0,0.5);
  --glow-p:   0 0 20px rgba(124,58,237,0.4);
  --glow-c:   0 0 20px rgba(6,182,212,0.4);
  --glow-g:   0 0 20px rgba(16,185,129,0.4);
  --glow-r:   0 0 20px rgba(239,68,68,0.4);

  --transition: 0.25s cubic-bezier(0.4,0,0.2,1);
  --transition-fast: 0.15s ease;
}

/* ---- App Shell ---- */
#app { min-height: 100vh; position: relative; }

/* ---- Screens ---- */
.screen {
  display: none;
  min-height: 100vh;
  width: 100%;
  position: relative;
  padding-bottom: 2rem;
}
.screen.active { display: block; }

/* ---- Glass Card ---- */
.glass-card {
  background: var(--glass);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
}

/* =====================================================
   HUD
   ===================================================== */
.hud {
  position: fixed;
  top: 0; left: 0; right: 0;
  z-index: 100;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0.6rem 1rem;
  background: rgba(10,10,26,0.85);
  backdrop-filter: blur(16px);
  border-bottom: 1px solid var(--border);
}
.hud.hidden { display: none; }
.hud-lives { display: flex; gap: 0.3rem; font-size: 1.3rem; }
.hud-center {
  display: flex; align-items: center; gap: 0.3rem;
  font-size: 0.9rem; color: var(--yellow);
}
.hud-streak-num { font-weight: 700; font-size: 1.1rem; }
.hud-streak-label { color: var(--text2); font-size: 0.75rem; }
.hud-right {
  display: flex; align-items: center; gap: 0.8rem;
  font-size: 0.9rem; font-weight: 600; color: var(--cyan);
}
.hud-xp-label { color: var(--text2); font-size: 0.75rem; font-weight: 400; }
.hud-timer {
  display: flex; align-items: center; gap: 0.3rem;
  color: var(--yellow); font-weight: 700;
}
.hud-timer.hidden { display: none; }
.hud-timer.urgent { color: var(--red); animation: pulse-red 1s infinite; }

/* =====================================================
   HOME SCREEN
   ===================================================== */
.home-particles {
  position: fixed; inset: 0; pointer-events: none; z-index: 0;
  overflow: hidden;
}
.particle {
  position: absolute;
  border-radius: 50%;
  opacity: 0.15;
  animation: float-particle linear infinite;
}

.home-wrap {
  position: relative; z-index: 1;
  max-width: 700px; margin: 0 auto;
  padding: 3rem 1.5rem 4rem;
  display: flex; flex-direction: column; align-items: center; gap: 2rem;
}

.home-logo { text-align: center; }
.home-logo-icon {
  font-size: 4rem; display: block; margin-bottom: 0.5rem;
  filter: drop-shadow(0 0 24px rgba(124,58,237,0.6));
}
.home-title {
  font-size: clamp(2.2rem, 6vw, 3.5rem);
  font-weight: 900; letter-spacing: -0.02em;
  color: var(--text);
}
.grad-text {
  background: var(--grad);
  -webkit-background-clip: text; -webkit-text-fill-color: transparent;
  background-clip: text;
}
.home-sub {
  color: var(--text2); font-size: 0.95rem; margin-top: 0.4rem;
}

/* Player banner on home */
.home-player-banner {
  width: 100%;
  display: flex; align-items: center; gap: 1rem;
  padding: 0.9rem 1.2rem;
  background: var(--glass);
  border: 1px solid var(--border);
  border-radius: var(--radius);
}
.home-player-banner.hidden { display: none; }
.banner-avatar { font-size: 2rem; }
.banner-info { flex: 1; min-width: 0; }
.banner-info > span { font-weight: 700; font-size: 1rem; }
.banner-xp-bar {
  height: 4px; background: var(--bg3);
  border-radius: 2px; margin: 0.3rem 0; overflow: hidden;
}
.banner-xp-fill {
  height: 100%; width: 0%;
  background: var(--grad);
  border-radius: 2px;
  transition: width 0.6s ease;
}
.banner-level-text { font-size: 0.75rem; color: var(--purple-l); }
.banner-stats { color: var(--yellow); font-size: 0.9rem; font-weight: 600; }

/* Home Nav */
.home-nav {
  width: 100%;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1rem;
}
.home-btn {
  display: flex; align-items: center; gap: 0.85rem;
  padding: 1rem 1.1rem;
  background: var(--glass);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  color: var(--text); text-align: left;
  transition: var(--transition);
  position: relative; overflow: hidden;
}
.home-btn::before {
  content: '';
  position: absolute; inset: 0;
  opacity: 0; transition: opacity var(--transition);
}
.home-btn:hover { border-color: var(--border-hover); transform: translateY(-2px); box-shadow: var(--shadow); }
.home-btn:hover::before { opacity: 1; }
.home-btn:active { transform: translateY(0); }

.home-btn--practice::before { background: linear-gradient(135deg, rgba(124,58,237,0.12), transparent); }
.home-btn--practice:hover { box-shadow: var(--glow-p); border-color: var(--purple); }
.home-btn--exam::before { background: linear-gradient(135deg, rgba(6,182,212,0.12), transparent); }
.home-btn--exam:hover { box-shadow: var(--glow-c); border-color: var(--cyan); }
.home-btn--matching::before { background: linear-gradient(135deg, rgba(16,185,129,0.12), transparent); }
.home-btn--matching:hover { box-shadow: var(--glow-g); border-color: var(--green); }
.home-btn--cases::before { background: linear-gradient(135deg, rgba(245,158,11,0.12), transparent); }
.home-btn--cases:hover { box-shadow: 0 0 20px rgba(245,158,11,0.4); border-color: var(--yellow); }
.home-btn--stats::before { background: linear-gradient(135deg, rgba(249,115,22,0.12), transparent); }
.home-btn--stats:hover { box-shadow: 0 0 20px rgba(249,115,22,0.3); border-color: var(--orange); }
.home-btn--config::before { background: linear-gradient(135deg, rgba(144,144,187,0.08), transparent); }
.home-btn--config:hover { border-color: var(--text2); }

.home-btn-icon { font-size: 1.7rem; flex-shrink: 0; }
.home-btn-text strong { display: block; font-size: 0.95rem; font-weight: 700; }
.home-btn-text small { font-size: 0.72rem; color: var(--text2); }

.home-footer { color: var(--text3); font-size: 0.72rem; text-align: center; }

/* =====================================================
   SCREEN HEADER (shared)
   ===================================================== */
.screen-head {
  display: flex; align-items: center; gap: 1rem;
  padding: 1.2rem 1.5rem 0.8rem;
  position: sticky; top: 0; z-index: 50;
  background: rgba(10,10,26,0.9);
  backdrop-filter: blur(16px);
  border-bottom: 1px solid var(--border);
}
.screen-head h2 { font-size: 1.2rem; font-weight: 700; }

/* =====================================================
   BUTTONS
   ===================================================== */
.btn-back {
  background: var(--glass);
  border: 1px solid var(--border);
  color: var(--text); border-radius: 50%;
  width: 36px; height: 36px;
  font-size: 1rem; flex-shrink: 0;
  transition: var(--transition);
}
.btn-back:hover { border-color: var(--purple); background: rgba(124,58,237,0.1); }

.btn-primary {
  background: var(--grad);
  color: #fff; border-radius: var(--radius-s);
  padding: 0.75rem 1.5rem;
  font-size: 0.95rem; font-weight: 700;
  transition: var(--transition);
  box-shadow: 0 4px 16px rgba(124,58,237,0.35);
}
.btn-primary:hover { transform: translateY(-1px); box-shadow: 0 6px 24px rgba(124,58,237,0.5); }
.btn-primary:active { transform: translateY(0); }
.btn-primary.btn-lg { padding: 0.9rem 2rem; font-size: 1rem; border-radius: var(--radius); }
.btn-primary.btn-full { width: 100%; margin-top: 1rem; }

.btn-secondary {
  background: var(--glass-hover);
  border: 1px solid var(--border);
  color: var(--text); border-radius: var(--radius-s);
  padding: 0.75rem 1.5rem;
  font-size: 0.9rem; font-weight: 600;
  transition: var(--transition);
}
.btn-secondary:hover { border-color: var(--border-hover); }

.btn-ghost {
  background: transparent;
  color: var(--text2); border-radius: var(--radius-s);
  padding: 0.65rem 1.2rem;
  font-size: 0.9rem;
  transition: var(--transition);
}
.btn-ghost:hover { color: var(--text); background: var(--glass); }

.btn-danger {
  background: var(--grad-red);
  color: #fff; border-radius: var(--radius-s);
  padding: 0.7rem 1.4rem;
  font-weight: 700; font-size: 0.9rem;
  transition: var(--transition);
}
.btn-danger:hover { transform: translateY(-1px); box-shadow: var(--glow-r); }

/* =====================================================
   SETUP SCREEN
   ===================================================== */
.setup-wrap {
  min-height: 100vh; display: flex;
  align-items: center; justify-content: center;
  padding: 2rem;
}
.setup-card {
  width: 100%; max-width: 420px;
  padding: 2.5rem 2rem;
  text-align: center;
  display: flex; flex-direction: column; gap: 1.2rem;
}
.setup-emoji { font-size: 3.5rem; }
.setup-card h2 { font-size: 1.5rem; font-weight: 800; }
.setup-card p { color: var(--text2); }

.field-input {
  width: 100%;
  background: var(--bg3);
  border: 1px solid var(--border);
  border-radius: var(--radius-s);
  color: var(--text); padding: 0.75rem 1rem;
  font-size: 1rem; outline: none;
  transition: var(--transition);
}
.field-input:focus { border-color: var(--purple); box-shadow: 0 0 0 3px rgba(124,58,237,0.2); }
.field-input::placeholder { color: var(--text3); }

/* =====================================================
   PRACTICE MENU
   ===================================================== */
.topic-wrap { padding: 1.5rem; }
.topic-intro { color: var(--text2); margin-bottom: 1.5rem; }

.topic-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(160px, 1fr));
  gap: 0.75rem; margin-bottom: 1rem;
}
.topic-card {
  background: var(--glass);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1rem 0.85rem;
  cursor: pointer;
  text-align: center;
  transition: var(--transition);
  display: flex; flex-direction: column; gap: 0.4rem;
}
.topic-card:hover {
  border-color: var(--purple);
  background: var(--glass-hover);
  transform: translateY(-2px);
  box-shadow: var(--glow-p);
}
.topic-card-icon { font-size: 1.8rem; }
.topic-card-name { font-size: 0.8rem; font-weight: 700; color: var(--text); }
.topic-card-count { font-size: 0.7rem; color: var(--text2); }

/* =====================================================
   QUIZ SCREEN
   ===================================================== */
.quiz-wrap {
  max-width: 740px; margin: 0 auto;
  padding: 4.5rem 1.25rem 3rem;
}
.quiz-progress-bar {
  height: 5px; background: var(--bg3);
  border-radius: 3px; overflow: hidden; margin-bottom: 1.5rem;
}
.quiz-progress-fill {
  height: 100%; background: var(--grad);
  border-radius: 3px; transition: width 0.4s ease;
}

.question-card {
  background: var(--glass);
  border: 1px solid var(--border);
  border-radius: var(--radius-l);
  padding: 1.8rem 1.6rem;
  margin-bottom: 1.2rem;
  animation: slide-up 0.3s ease;
}
.question-meta {
  display: flex; align-items: center; gap: 0.6rem;
  flex-wrap: wrap; margin-bottom: 1rem;
}
.q-badge {
  font-size: 0.68rem; font-weight: 700; letter-spacing: 0.05em;
  padding: 0.2rem 0.6rem; border-radius: 20px;
  text-transform: uppercase;
}
.q-badge--topic  { background: rgba(124,58,237,0.2); color: var(--purple-l); border: 1px solid rgba(124,58,237,0.3); }
.q-badge--easy   { background: rgba(16,185,129,0.15); color: var(--green-l); border: 1px solid rgba(16,185,129,0.3); }
.q-badge--medium { background: rgba(245,158,11,0.15); color: var(--yellow-l); border: 1px solid rgba(245,158,11,0.3); }
.q-badge--hard   { background: rgba(239,68,68,0.15); color: var(--red-l); border: 1px solid rgba(239,68,68,0.3); }
.q-badge--xp     { background: rgba(6,182,212,0.15); color: var(--cyan-l); border: 1px solid rgba(6,182,212,0.3); }
.question-num    { font-size: 0.75rem; color: var(--text2); margin-left: auto; }
.question-type-label { font-size: 0.7rem; color: var(--text3); font-style: italic; }

.question-text {
  font-size: 1.05rem; font-weight: 600; line-height: 1.55;
  margin-bottom: 0.5rem; color: var(--text);
}
.question-case-story {
  background: rgba(124,58,237,0.08);
  border-left: 3px solid var(--purple);
  border-radius: 0 var(--radius-s) var(--radius-s) 0;
  padding: 0.9rem 1rem;
  margin-bottom: 1rem;
  font-size: 0.9rem; color: var(--text2); line-height: 1.6;
}

.options-list {
  display: flex; flex-direction: column; gap: 0.65rem;
  margin-top: 1.2rem;
}
.option-btn {
  width: 100%; text-align: left;
  background: rgba(255,255,255,0.03);
  border: 1.5px solid var(--border);
  border-radius: var(--radius);
  padding: 0.85rem 1.1rem;
  color: var(--text); font-size: 0.92rem;
  transition: var(--transition);
  display: flex; align-items: flex-start; gap: 0.8rem;
}
.option-btn:hover:not(:disabled) {
  border-color: var(--purple-l);
  background: rgba(124,58,237,0.08);
  transform: translateX(3px);
}
.option-letter {
  min-width: 26px; height: 26px;
  border-radius: 50%;
  display: flex; align-items: center; justify-content: center;
  background: var(--bg3); border: 1px solid var(--border);
  font-size: 0.75rem; font-weight: 700; flex-shrink: 0;
  transition: var(--transition);
}
.option-text { flex: 1; line-height: 1.45; padding-top: 2px; }

.option-btn.selected { border-color: var(--purple); background: rgba(124,58,237,0.12); }
.option-btn.selected .option-letter { background: var(--purple); border-color: var(--purple); color: #fff; }
.option-btn.correct { border-color: var(--green) !important; background: rgba(16,185,129,0.12) !important; animation: flash-green 0.4s ease; }
.option-btn.correct .option-letter { background: var(--green) !important; border-color: var(--green) !important; color: #fff !important; }
.option-btn.wrong { border-color: var(--red) !important; background: rgba(239,68,68,0.1) !important; animation: shake 0.4s ease; }
.option-btn.wrong .option-letter { background: var(--red) !important; border-color: var(--red) !important; color: #fff !important; }
.option-btn.dimmed { opacity: 0.45; }
.option-btn:disabled { cursor: default; }

.ordering-list {
  display: flex; flex-direction: column; gap: 0.5rem;
  margin-top: 1rem;
}
.ordering-item {
  display: flex; align-items: center; gap: 0.8rem;
  padding: 0.7rem 1rem;
  background: var(--glass);
  border: 1.5px solid var(--border);
  border-radius: var(--radius-s);
  cursor: grab; transition: var(--transition);
  user-select: none;
}
.ordering-item:hover { border-color: var(--purple); background: var(--glass-hover); }
.ordering-item.dragging { opacity: 0.4; cursor: grabbing; }
.ordering-handle { color: var(--text3); font-size: 1rem; }
.ordering-num {
  width: 24px; height: 24px; border-radius: 50%;
  background: var(--bg3); border: 1px solid var(--border);
  display: flex; align-items: center; justify-content: center;
  font-size: 0.75rem; font-weight: 700; color: var(--purple-l);
  flex-shrink: 0;
}
.ordering-text { flex: 1; font-size: 0.88rem; }
.ordering-item.order-correct { border-color: var(--green) !important; background: rgba(16,185,129,0.08) !important; }
.ordering-item.order-wrong   { border-color: var(--red) !important; background: rgba(239,68,68,0.08) !important; }

.drag-concept-area {
  display: flex; gap: 1rem; flex-wrap: wrap; margin-top: 1rem;
}
.drag-zone {
  flex: 1; min-width: 140px;
  background: var(--glass);
  border: 2px dashed var(--border);
  border-radius: var(--radius);
  padding: 1rem 0.75rem; min-height: 120px;
  transition: var(--transition);
}
.drag-zone.drag-over { border-color: var(--purple); background: rgba(124,58,237,0.08); }
.drag-zone-title { font-size: 0.75rem; font-weight: 700; color: var(--purple-l); margin-bottom: 0.5rem; text-align: center; }
.drag-chips { display: flex; flex-wrap: wrap; gap: 0.4rem; justify-content: center; }
.drag-chip {
  background: var(--bg3); border: 1px solid var(--border);
  border-radius: 20px; padding: 0.3rem 0.7rem;
  font-size: 0.78rem; cursor: grab; user-select: none;
  transition: var(--transition); color: var(--text);
}
.drag-chip:hover { border-color: var(--purple); }
.drag-chip.dragging { opacity: 0.4; cursor: grabbing; }

.feedback-card {
  border-radius: var(--radius);
  padding: 1.2rem 1.4rem;
  margin-top: 1rem;
  animation: slide-up 0.35s ease;
}
.feedback-card.correct { background: rgba(16,185,129,0.1); border: 1px solid rgba(16,185,129,0.3); }
.feedback-card.wrong   { background: rgba(239,68,68,0.08); border: 1px solid rgba(239,68,68,0.3); }
.feedback-header {
  display: flex; align-items: center; gap: 0.6rem;
  font-size: 1rem; font-weight: 700; margin-bottom: 0.7rem;
}
.feedback-header.correct { color: var(--green-l); }
.feedback-header.wrong   { color: var(--red-l); }
.feedback-explanation { font-size: 0.88rem; color: var(--text2); line-height: 1.55; margin-bottom: 0.8rem; }
.feedback-option-exp {
  background: rgba(255,255,255,0.03);
  border-radius: var(--radius-s);
  padding: 0.6rem 0.8rem;
  margin-top: 0.5rem; font-size: 0.82rem; color: var(--text2);
}
.feedback-option-exp strong { color: var(--text); font-size: 0.8rem; }
.feedback-ref { font-size: 0.72rem; color: var(--text3); margin-top: 0.6rem; font-style: italic; }

.quiz-action-row {
  display: flex; gap: 0.8rem; justify-content: flex-end;
  margin-top: 1.2rem; flex-wrap: wrap;
}
.btn-submit {
  background: var(--grad);
  color: #fff; border-radius: var(--radius-s);
  padding: 0.8rem 1.8rem;
  font-weight: 700; font-size: 0.95rem;
  transition: var(--transition);
  box-shadow: 0 4px 16px rgba(124,58,237,0.35);
}
.btn-submit:hover { transform: translateY(-1px); box-shadow: 0 6px 24px rgba(124,58,237,0.5); }
.btn-submit:disabled { opacity: 0.5; cursor: default; transform: none; }
.btn-continue {
  background: var(--grad-green);
  color: #fff; border-radius: var(--radius-s);
  padding: 0.8rem 1.8rem;
  font-weight: 700; font-size: 0.95rem;
  transition: var(--transition);
  box-shadow: 0 4px 16px rgba(16,185,129,0.3);
}
.btn-continue:hover { transform: translateY(-1px); box-shadow: 0 6px 20px rgba(16,185,129,0.5); }

/* =====================================================
   GAME OVER / LEVEL UP OVERLAYS
   ===================================================== */
.gameover-overlay {
  position: fixed; inset: 0; z-index: 200;
  background: rgba(0,0,0,0.85);
  display: flex; align-items: center; justify-content: center;
  backdrop-filter: blur(8px);
}
.gameover-overlay.hidden { display: none; }
.gameover-card {
  background: var(--bg2);
  border: 1px solid rgba(239,68,68,0.4);
  border-radius: var(--radius-xl);
  padding: 3rem 2.5rem;
  text-align: center; max-width: 440px; width: 90%;
  animation: pop-in 0.4s cubic-bezier(0.34,1.56,0.64,1);
}
.gameover-icon { font-size: 4rem; display: block; margin-bottom: 1rem; }
.gameover-card h2 { font-size: 2rem; font-weight: 900; color: var(--red-l); margin-bottom: 0.5rem; }
.gameover-card p { color: var(--text2); margin-bottom: 1.5rem; }
.gameover-actions { display: flex; gap: 0.8rem; justify-content: center; flex-wrap: wrap; }

.levelup-overlay {
  position: fixed; inset: 0; z-index: 300;
  background: rgba(0,0,0,0.8);
  display: flex; align-items: center; justify-content: center;
  backdrop-filter: blur(12px);
}
.levelup-overlay.hidden { display: none; }
.levelup-card {
  text-align: center; padding: 3rem 2.5rem;
  background: var(--bg2);
  border: 1px solid var(--purple);
  border-radius: var(--radius-xl); max-width: 420px; width: 90%;
  box-shadow: var(--glow-p);
  animation: pop-in 0.5s cubic-bezier(0.34,1.56,0.64,1);
}
.levelup-icon { font-size: 4rem; display: block; margin-bottom: 1rem; }
.levelup-card h2 { font-size: 1.4rem; color: var(--text2); margin-bottom: 0.3rem; }
.levelup-card .level-name {
  font-size: 2rem; font-weight: 900;
  background: var(--grad); -webkit-background-clip: text;
  -webkit-text-fill-color: transparent; background-clip: text;
}
.levelup-card p { color: var(--text2); margin: 0.8rem 0 1.5rem; }

/* =====================================================
   EXAM SCREENS
   ===================================================== */
.exam-intro-wrap {
  min-height: 100vh; display: flex;
  align-items: center; justify-content: center; padding: 2rem;
}
.exam-intro-card {
  max-width: 480px; width: 100%;
  padding: 2.5rem 2rem; text-align: center;
  display: flex; flex-direction: column; gap: 1.2rem;
}
.exam-intro-icon { font-size: 3.5rem; }
.exam-intro-card h2 { font-size: 1.6rem; font-weight: 800; }
.exam-rules { text-align: left; display: flex; flex-direction: column; gap: 0.6rem; }
.exam-rules li {
  font-size: 0.9rem; color: var(--text2);
  padding: 0.5rem 0.75rem;
  background: var(--glass); border-radius: var(--radius-s); border: 1px solid var(--border);
}

.exam-wrap { padding: 4.5rem 1.25rem 3rem; max-width: 800px; margin: 0 auto; }
.exam-question-nav {
  display: flex; flex-wrap: wrap; gap: 0.4rem; margin-bottom: 1.5rem;
}
.exam-nav-dot {
  width: 32px; height: 32px; border-radius: 50%;
  border: 1.5px solid var(--border);
  background: var(--glass);
  font-size: 0.72rem; font-weight: 700; color: var(--text2);
  cursor: pointer; transition: var(--transition);
  display: flex; align-items: center; justify-content: center;
}
.exam-nav-dot:hover { border-color: var(--purple); color: var(--text); }
.exam-nav-dot.current { border-color: var(--purple); background: rgba(124,58,237,0.2); color: var(--purple-l); }
.exam-nav-dot.answered { border-color: var(--cyan); background: rgba(6,182,212,0.12); color: var(--cyan-l); }
.exam-submit-row { display: flex; justify-content: center; margin-top: 1.5rem; }

/* Exam Results */
.exam-results-wrap { max-width: 740px; margin: 0 auto; padding: 2rem 1.25rem 4rem; }
.exam-score-card {
  background: var(--glass); border: 1px solid var(--border);
  border-radius: var(--radius-xl); padding: 2.5rem 2rem;
  text-align: center; margin-bottom: 1.5rem;
}
.exam-score-num {
  font-size: 4rem; font-weight: 900;
  background: var(--grad); -webkit-background-clip: text;
  -webkit-text-fill-color: transparent; background-clip: text;
}
.exam-score-label { font-size: 1.1rem; color: var(--text2); margin-bottom: 1rem; }
.exam-score-details {
  display: flex; gap: 1rem; justify-content: center; flex-wrap: wrap;
  margin-top: 1rem;
}
.exam-score-detail {
  background: var(--bg3); border: 1px solid var(--border);
  border-radius: var(--radius); padding: 0.6rem 1rem;
  text-align: center;
}
.exam-score-detail span { display: block; }
.exam-score-detail .detail-num { font-size: 1.3rem; font-weight: 800; color: var(--cyan); }
.exam-score-detail .detail-label { font-size: 0.72rem; color: var(--text2); }
.exam-review-section { background: var(--glass); border: 1px solid var(--border); border-radius: var(--radius-l); padding: 1.5rem; margin-bottom: 1rem; }
.exam-review-section h3 { font-size: 0.85rem; font-weight: 700; text-transform: uppercase; letter-spacing: 0.06em; color: var(--text2); margin-bottom: 1rem; }
.exam-review-item {
  border-bottom: 1px solid var(--border); padding: 0.85rem 0;
  font-size: 0.88rem;
}
.exam-review-item:last-child { border-bottom: none; }
.exam-review-item.r-correct .review-indicator { color: var(--green-l); }
.exam-review-item.r-wrong   .review-indicator { color: var(--red-l); }
.review-indicator { font-size: 0.8rem; font-weight: 700; margin-bottom: 0.3rem; }
.review-q-text { color: var(--text); font-weight: 600; margin-bottom: 0.3rem; }
.review-answers { display: flex; gap: 0.5rem; flex-wrap: wrap; font-size: 0.8rem; color: var(--text2); }
.review-exp { font-size: 0.8rem; color: var(--text2); margin-top: 0.4rem; line-height: 1.5; }

/* =====================================================
   MATCHING SCREEN
   ===================================================== */
.matching-menu-wrap { padding: 1.5rem; }
.matching-sets-list { display: flex; flex-direction: column; gap: 0.75rem; }
.matching-set-card {
  background: var(--glass); border: 1px solid var(--border);
  border-radius: var(--radius); padding: 1rem 1.2rem;
  display: flex; align-items: center; gap: 1rem;
  cursor: pointer; transition: var(--transition);
}
.matching-set-card:hover { border-color: var(--green); background: rgba(16,185,129,0.06); transform: translateX(4px); }
.matching-set-icon { font-size: 1.6rem; }
.matching-set-info strong { display: block; font-size: 0.95rem; }
.matching-set-info span   { font-size: 0.78rem; color: var(--text2); }
.matching-set-badge {
  margin-left: auto; font-size: 0.72rem;
  background: rgba(16,185,129,0.2); color: var(--green-l);
  border: 1px solid rgba(16,185,129,0.3);
  border-radius: 20px; padding: 0.2rem 0.6rem;
}

.matching-wrap { max-width: 780px; margin: 0 auto; padding: 4.5rem 1.25rem 3rem; }

/* =====================================================
   CASES SCREEN
   ===================================================== */
.cases-list-wrap { padding: 1.5rem; }
.case-card {
  background: var(--glass); border: 1px solid var(--border);
  border-radius: var(--radius); padding: 1.2rem 1.4rem;
  margin-bottom: 0.8rem; cursor: pointer; transition: var(--transition);
  display: flex; align-items: flex-start; gap: 1rem;
}
.case-card:hover { border-color: var(--yellow); background: rgba(245,158,11,0.06); transform: translateX(4px); }
.case-icon { font-size: 2rem; flex-shrink: 0; }
.case-info { flex: 1; }
.case-info strong { display: block; font-size: 0.95rem; font-weight: 700; margin-bottom: 0.25rem; }
.case-info p { font-size: 0.82rem; color: var(--text2); line-height: 1.45; }
.case-meta { display: flex; gap: 0.4rem; margin-top: 0.4rem; flex-wrap: wrap; }
.case-meta-badge {
  font-size: 0.68rem; padding: 0.15rem 0.5rem;
  background: rgba(245,158,11,0.15); color: var(--yellow-l);
  border: 1px solid rgba(245,158,11,0.3); border-radius: 20px;
}

.case-story-wrap { max-width: 740px; margin: 0 auto; padding: 4.5rem 1.25rem 3rem; }
.case-story-card {
  background: var(--glass); border: 1px solid var(--border);
  border-radius: var(--radius-l); padding: 2rem 1.8rem; margin-bottom: 1.5rem;
}
.case-story-card h2 { font-size: 1.3rem; font-weight: 800; margin-bottom: 0.3rem; }
.case-story-subtitle { color: var(--text2); font-size: 0.85rem; margin-bottom: 1.2rem; }
.case-story-text { font-size: 0.92rem; color: var(--text2); line-height: 1.7; border-left: 3px solid var(--yellow); padding-left: 1rem; }
.case-story-meta { display: flex; gap: 0.5rem; flex-wrap: wrap; margin-top: 1rem; }

.case-resolution-wrap { max-width: 740px; margin: 0 auto; padding: 4.5rem 1.25rem 3rem; }
.resolution-card {
  background: var(--glass); border: 1px solid rgba(16,185,129,0.3);
  border-radius: var(--radius-l); padding: 2rem 1.8rem; margin-bottom: 1rem;
}
.resolution-score { text-align: center; margin-bottom: 1.5rem; }
.resolution-score-num {
  font-size: 3rem; font-weight: 900;
  background: var(--grad-green); -webkit-background-clip: text;
  -webkit-text-fill-color: transparent; background-clip: text;
}
.resolution-score-label { color: var(--text2); font-size: 0.85rem; }
.resolution-section { margin-bottom: 1.2rem; }
.resolution-section h3 { font-size: 0.85rem; font-weight: 700; color: var(--green-l); margin-bottom: 0.6rem; text-transform: uppercase; letter-spacing: 0.06em; }
.resolution-text { font-size: 0.9rem; color: var(--text2); line-height: 1.6; }

/* =====================================================
   STATS SCREEN
   ===================================================== */
.stats-wrap { max-width: 740px; margin: 0 auto; padding: 1.5rem; display: flex; flex-direction: column; gap: 1.2rem; }
.stats-hero {
  background: var(--glass); border: 1px solid var(--border);
  border-radius: var(--radius-l); padding: 1.8rem 1.5rem; text-align: center;
}
.stats-level-badge {
  display: inline-block; background: var(--grad);
  border-radius: 20px; padding: 0.4rem 1.2rem;
  font-size: 0.85rem; font-weight: 700; color: #fff; margin-bottom: 0.8rem;
}
.stats-xp-display {
  font-size: 3rem; font-weight: 900;
  background: var(--grad); -webkit-background-clip: text;
  -webkit-text-fill-color: transparent; background-clip: text;
}
.stats-xp-label { color: var(--text2); font-size: 0.85rem; }
.stats-xp-bar { height: 8px; background: var(--bg3); border-radius: 4px; overflow: hidden; margin: 0.8rem auto; max-width: 320px; }
.stats-xp-fill { height: 100%; background: var(--grad); border-radius: 4px; transition: width 0.8s ease; }
.stats-grid {
  display: grid; grid-template-columns: repeat(auto-fill, minmax(160px,1fr)); gap: 0.75rem;
}
.stat-card {
  background: var(--glass); border: 1px solid var(--border);
  border-radius: var(--radius); padding: 1.1rem; text-align: center;
}
.stat-card:hover { border-color: var(--border-hover); transform: translateY(-2px); }
.stat-icon { font-size: 1.6rem; display: block; margin-bottom: 0.4rem; }
.stat-num { font-size: 1.6rem; font-weight: 900; color: var(--cyan); }
.stat-label { font-size: 0.72rem; color: var(--text2); margin-top: 0.2rem; }

.topic-stats-section { background: var(--glass); border: 1px solid var(--border); border-radius: var(--radius-l); padding: 1.4rem; }
.topic-stats-section h3 { font-size: 0.9rem; font-weight: 700; margin-bottom: 1rem; color: var(--text2); text-transform: uppercase; letter-spacing: 0.06em; }
.topic-stat-row { display: flex; align-items: center; gap: 0.8rem; margin-bottom: 0.6rem; }
.topic-stat-name { width: 130px; font-size: 0.8rem; color: var(--text2); flex-shrink: 0; }
.topic-stat-bar { flex: 1; height: 6px; background: var(--bg3); border-radius: 3px; overflow: hidden; }
.topic-stat-fill { height: 100%; border-radius: 3px; transition: width 0.6s ease; }
.topic-stat-pct { width: 36px; text-align: right; font-size: 0.75rem; font-weight: 700; }

.achievements-section { background: var(--glass); border: 1px solid var(--border); border-radius: var(--radius-l); padding: 1.4rem; }
.achievements-section h3 { font-size: 0.9rem; font-weight: 700; margin-bottom: 1rem; color: var(--text2); text-transform: uppercase; letter-spacing: 0.06em; }
.achievements-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(130px,1fr)); gap: 0.6rem; }
.achievement-badge {
  background: var(--bg3); border: 1px solid var(--border);
  border-radius: var(--radius); padding: 0.85rem 0.7rem; text-align: center;
}
.achievement-badge.unlocked { border-color: var(--yellow); background: rgba(245,158,11,0.08); }
.achievement-badge.unlocked:hover { transform: translateY(-2px); box-shadow: 0 0 16px rgba(245,158,11,0.3); }
.achievement-badge-icon { font-size: 1.8rem; display: block; margin-bottom: 0.4rem; }
.achievement-badge:not(.unlocked) .achievement-badge-icon { filter: grayscale(1) opacity(0.4); }
.achievement-badge-name { font-size: 0.7rem; font-weight: 700; }
.achievement-badge-desc { font-size: 0.65rem; color: var(--text2); margin-top: 0.2rem; }

/* =====================================================
   CONFIG SCREEN
   ===================================================== */
.config-wrap { max-width: 560px; margin: 0 auto; padding: 1.5rem; display: flex; flex-direction: column; gap: 0.8rem; }
.config-section { background: var(--glass); border: 1px solid var(--border); border-radius: var(--radius); overflow: hidden; }
.config-section-title { padding: 0.8rem 1.2rem 0.4rem; font-size: 0.72rem; font-weight: 700; color: var(--text3); text-transform: uppercase; letter-spacing: 0.08em; }
.config-row { display: flex; align-items: center; justify-content: space-between; padding: 0.85rem 1.2rem; border-top: 1px solid var(--border); font-size: 0.9rem; }
.config-row:first-of-type { border-top: none; }
.config-row-label { color: var(--text); }
.config-row-sub { font-size: 0.75rem; color: var(--text2); margin-top: 0.15rem; }
.toggle { position: relative; width: 44px; height: 24px; }
.toggle input { opacity: 0; width: 0; height: 0; }
.toggle-track { position: absolute; inset: 0; background: var(--bg3); border-radius: 12px; cursor: pointer; transition: var(--transition); border: 1px solid var(--border); }
.toggle input:checked + .toggle-track { background: var(--purple); border-color: var(--purple); }
.toggle-track::after { content: ''; position: absolute; width: 18px; height: 18px; border-radius: 50%; background: #fff; top: 2px; left: 2px; transition: transform var(--transition); }
.toggle input:checked + .toggle-track::after { transform: translateX(20px); }

/* =====================================================
   TOASTS / POPUPS
   ===================================================== */
.toast-container { position: fixed; top: 1rem; right: 1rem; z-index: 500; display: flex; flex-direction: column; gap: 0.5rem; pointer-events: none; }
.toast {
  background: var(--bg2); border: 1px solid var(--border);
  border-radius: var(--radius); padding: 0.75rem 1.1rem;
  font-size: 0.88rem; color: var(--text); box-shadow: var(--shadow);
  animation: slide-in-right 0.3s ease, fade-out 0.3s ease 2.7s forwards;
  max-width: 300px;
}
.toast.toast--success { border-color: var(--green); color: var(--green-l); }
.toast.toast--error   { border-color: var(--red); color: var(--red-l); }
.toast.toast--info    { border-color: var(--cyan); color: var(--cyan-l); }

.xp-popup { position: fixed; pointer-events: none; z-index: 400; font-size: 1.1rem; font-weight: 900; color: var(--cyan); text-shadow: 0 0 12px var(--cyan); animation: float-xp 1.2s ease forwards; }

.achievement-popup {
  position: fixed; bottom: 1.5rem; left: 50%; transform: translateX(-50%);
  z-index: 600; background: var(--bg2); border: 1px solid var(--yellow);
  border-radius: var(--radius-l); padding: 1rem 1.5rem;
  display: flex; align-items: center; gap: 1rem;
  box-shadow: 0 0 32px rgba(245,158,11,0.3);
  max-width: 380px; width: 90%;
  animation: slide-up 0.4s cubic-bezier(0.34,1.56,0.64,1);
}
.achievement-popup.hidden { display: none; }
.achievement-popup-icon { font-size: 2.5rem; flex-shrink: 0; }
.achievement-popup-text strong { display: block; font-size: 0.75rem; color: var(--yellow-l); text-transform: uppercase; letter-spacing: 0.06em; }
.achievement-popup-text .achievement-name { font-size: 1rem; font-weight: 800; color: var(--text); }
.achievement-popup-text .achievement-desc { font-size: 0.78rem; color: var(--text2); }

.confetti-canvas { position: fixed; inset: 0; z-index: 999; pointer-events: none; width: 100%; height: 100%; }

/* =====================================================
   RESPONSIVE
   ===================================================== */
@media (max-width: 600px) {
  .home-nav { grid-template-columns: 1fr; }
  .home-title { font-size: 2.2rem; }
  .quiz-wrap { padding: 4.5rem 1rem 4rem; }
  .question-card { padding: 1.2rem 1rem; }
  .topic-grid { grid-template-columns: repeat(auto-fill, minmax(130px,1fr)); }
  .stats-grid { grid-template-columns: repeat(2, 1fr); }
  .exam-wrap { padding: 4.5rem 1rem 3rem; }
  .case-story-wrap, .case-resolution-wrap { padding: 4.5rem 1rem 3rem; }
}