@import url('https://fonts.googleapis.com/css2?family=Inter:wght@300;400;500;600;700;800;900&display=swap');

/* ===== Design Tokens ===== */
:root {
  --bg:         #EEF2FF;
  --bg-card:    #FFFFFF;
  --bg-hover:   #F8FAFF;
  --bg-input:   #F1F5FF;

  --primary:        #4F6EF7;
  --primary-dark:   #3A56D4;
  --primary-light:  #EEF1FF;
  --primary-glow:   rgba(79,110,247,0.18);

  --accent:         #7C5CFC;
  --accent-light:   #F0EBFF;

  --success:        #22C55E;
  --success-bg:     #F0FDF4;
  --success-border: #BBF7D0;

  --warning:        #F59E0B;
  --warning-bg:     #FFFBEB;

  --danger:         #EF4444;
  --danger-bg:      #FEF2F2;
  --danger-border:  #FECACA;

  --text:       #1E293B;
  --text-2:     #475569;
  --text-3:     #94A3B8;

  --border:     #E2E8F0;
  --border-2:   #CBD5E1;

  --shadow-sm:  0 1px 3px rgba(0,0,0,0.08), 0 1px 2px rgba(0,0,0,0.04);
  --shadow:     0 4px 16px rgba(0,0,0,0.08), 0 2px 6px rgba(0,0,0,0.04);
  --shadow-lg:  0 10px 40px rgba(0,0,0,0.12), 0 4px 12px rgba(0,0,0,0.06);

  --radius-sm:  8px;
  --radius:     12px;
  --radius-lg:  18px;
  --radius-xl:  24px;

  --transition: all 0.2s cubic-bezier(0.4,0,0.2,1);
}

/* ===== Reset ===== */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; font-size: 16px; }
body {
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.6;
  min-height: 100vh;
  -webkit-font-smoothing: antialiased;
}
img { max-width: 100%; display: block; }
a { color: inherit; text-decoration: none; }
button { font-family: inherit; }
::-webkit-scrollbar { width: 5px; height: 5px; }
::-webkit-scrollbar-track { background: var(--bg); }
::-webkit-scrollbar-thumb { background: var(--border-2); border-radius: 3px; }

/* ===== Layout ===== */
.container { max-width: 1120px; margin: 0 auto; padding: 0 20px; }

/* ===== Navbar ===== */
.navbar {
  background: #fff;
  border-bottom: 1px solid var(--border);
  box-shadow: var(--shadow-sm);
  position: sticky; top: 0; z-index: 100;
}
.navbar-inner {
  max-width: 1120px; margin: 0 auto; padding: 0 20px;
  display: flex; align-items: center; justify-content: space-between;
  height: 64px; gap: 16px;
}
.nav-brand { display: flex; align-items: center; gap: 10px; flex-shrink: 0; }
.nav-logo {
  width: 36px; height: 36px; border-radius: 10px;
  background: var(--primary);
  color: #fff;
  display: flex; align-items: center; justify-content: center;
  font-size: 17px; box-shadow: 0 4px 12px var(--primary-glow);
}
.nav-brand-text { font-size: 18px; font-weight: 800; color: var(--text); }
.nav-links { display: flex; align-items: center; gap: 4px; }
.nav-link {
  padding: 7px 14px; border-radius: var(--radius-sm);
  font-size: 14px; font-weight: 500; color: var(--text-2);
  cursor: pointer; border: none; background: transparent;
  transition: var(--transition); display: flex; align-items: center; gap: 6px;
}
.nav-link:hover { background: var(--bg-hover); color: var(--text); }
.nav-link.active { background: var(--primary); color: #fff; }
.nav-link.btn-outline {
  border: 1.5px solid var(--border-2); color: var(--text-2);
  background: #fff;
}
.nav-link.btn-outline:hover { border-color: var(--primary); color: var(--primary); }
.nav-dropdown { position: relative; }
.nav-dropdown-toggle { height: 36px; }
.nav-caret { font-size: 11px; transition: transform .2s ease; }
.nav-dropdown-menu {
  position: absolute; top: calc(100% + 8px); right: 0;
  min-width: 168px; padding: 6px;
  background: #fff; border: 1px solid var(--border);
  border-radius: var(--radius); box-shadow: var(--shadow);
  opacity: 0; visibility: hidden; transform: translateY(-4px);
  transition: var(--transition); z-index: 120;
}
.nav-dropdown:hover .nav-dropdown-menu,
.nav-dropdown:focus-within .nav-dropdown-menu {
  opacity: 1; visibility: visible; transform: translateY(0);
}
.nav-dropdown:hover .nav-caret,
.nav-dropdown:focus-within .nav-caret { transform: rotate(180deg); }
.nav-dropdown-item {
  display: flex; align-items: center; gap: 8px;
  padding: 9px 10px; border-radius: var(--radius-sm);
  color: var(--text-2); font-size: 14px; font-weight: 600;
  transition: var(--transition);
}
.nav-dropdown-item:hover { background: var(--bg-hover); color: var(--text); }
.nav-dropdown-item.active { background: var(--primary-light); color: var(--primary); }

/* ===== Hero ===== */
.hero {
  display: grid;
  grid-template-columns: 1fr 420px;
  gap: 48px;
  align-items: center;
  padding: 50px 0 30px;
}
.hero-badge {
  display: inline-flex; align-items: center; gap: 6px;
  padding: 6px 14px; border-radius: 50px;
  background: var(--primary-light);
  border: 1px solid rgba(79,110,247,0.25);
  color: var(--primary); font-size: 13px; font-weight: 600;
  margin-bottom: 20px;
}
.hero h1 {
  font-size: clamp(2rem, 4.5vw, 3.2rem);
  font-weight: 900;
  line-height: 1.15;
  color: var(--text);
  margin-bottom: 16px;
  letter-spacing: 0;
}
.hero h1 span { color: var(--primary); }
.hero-desc {
  font-size: 16px; color: var(--text-2); line-height: 1.7;
  margin-bottom: 28px; max-width: 440px;
}

/* Hero stats */
.hero-stats {
  width: min(100%, 610px);
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 8px;
  padding: 8px;
  background: rgba(255,255,255,0.68);
  border: 1px solid rgba(203,213,225,0.75);
  border-radius: 18px;
  box-shadow: var(--shadow-sm);
  backdrop-filter: blur(10px);
}
.stat-pill {
  min-width: 0;
  display: flex; align-items: center; gap: 10px;
  padding: 10px 12px;
  border-radius: 12px;
  background: linear-gradient(180deg, rgba(255,255,255,0.95), rgba(248,250,255,0.92));
  border: 1px solid rgba(226,232,240,0.86);
}
.stat-icon {
  width: 34px; height: 34px; border-radius: 10px;
  display: flex; align-items: center; justify-content: center;
  font-size: 15px; flex-shrink: 0;
}
.stat-icon.blue { background: var(--primary-light); color: var(--primary); }
.stat-icon.green { background: var(--success-bg); color: #15803D; }
.stat-icon.purple { background: var(--accent-light); color: var(--accent); }
.stat-num { font-size: 24px; font-weight: 900; color: var(--text); line-height: .95; }
.stat-lbl { font-size: 11.5px; color: var(--text-3); margin-top: 3px; white-space: nowrap; }

/* Hero illustration */
.hero-illustration {
  position: relative;
  display: flex; align-items: center; justify-content: center;
}
.hero-img-wrap {
  width: 100%;
  max-width: 400px;
  border-radius: 28px;
  overflow: hidden;
  box-shadow: 0 20px 60px rgba(79,110,247,0.22), 0 8px 24px rgba(124,92,252,0.14);
  border: 1.5px solid rgba(79,110,247,0.12);
  transition: transform 0.35s ease, box-shadow 0.35s ease;
}
.hero-img-wrap:hover {
  transform: translateY(-6px) scale(1.01);
  box-shadow: 0 28px 72px rgba(79,110,247,0.28), 0 12px 32px rgba(124,92,252,0.18);
}
.hero-img {
  width: 100%;
  height: auto;
  display: block;
}

/* Quiz card mockup inside illustration */
.mock-card {
  background: #fff;
  border-radius: 16px;
  padding: 20px;
  width: 75%;
  box-shadow: 0 8px 32px rgba(79,110,247,0.15);
  position: relative; z-index: 2;
}
.mock-title { font-size: 11px; font-weight: 600; color: var(--text-3); margin-bottom: 12px; }
.mock-opt {
  display: flex; align-items: center; gap: 8px;
  padding: 8px 10px; border-radius: 8px; margin-bottom: 6px;
  background: var(--bg); border: 1.5px solid var(--border);
  font-size: 11px; color: var(--text-2);
}
.mock-opt.selected { background: var(--primary-light); border-color: var(--primary); color: var(--primary); }
.mock-letter {
  width: 18px; height: 18px; border-radius: 50%;
  background: var(--border); display: flex; align-items: center;
  justify-content: center; font-size: 9px; font-weight: 700; flex-shrink: 0;
}
.mock-opt.selected .mock-letter { background: var(--primary); color: #fff; }
.float-badge {
  position: absolute; background: #fff;
  border-radius: 12px; padding: 8px 12px;
  box-shadow: var(--shadow);
  font-size: 11px; font-weight: 600; color: var(--text);
  display: flex; align-items: center; gap: 6px; z-index: 3;
}
.float-badge.top-right { top: 24px; right: -16px; }
.float-badge.bottom-left { bottom: 24px; left: -16px; }

/* ===== Section ===== */
.section { margin-bottom: 40px; }
.section-header {
  display: flex; align-items: flex-start;
  justify-content: space-between; margin-bottom: 20px;
  gap: 16px; flex-wrap: wrap;
}
.section-title {
  font-size: 18px; font-weight: 800; color: var(--text);
  display: flex; align-items: center; gap: 8px;
}
.section-sub { font-size: 13px; color: var(--text-3); margin-top: 3px; }

/* ===== Cards ===== */
.card {
  background: var(--bg-card); border: 1px solid var(--border);
  border-radius: var(--radius-lg); padding: 24px;
  box-shadow: var(--shadow-sm); transition: var(--transition);
}
.card:hover { box-shadow: var(--shadow); }

.card-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(300px, 1fr)); gap: 16px; }

/* Dataset card */
.dataset-card {
  background: #fff;
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 14px 20px;
  box-shadow: var(--shadow-sm);
  transition: var(--transition);
  cursor: pointer;
  display: flex;
  align-items: center;
  gap: 16px;
  position: relative;
}
.dataset-card:hover {
  box-shadow: var(--shadow);
  transform: translateY(-2px);
  border-color: var(--primary);
}
.dataset-card-header {
  display: flex;
  align-items: center;
  gap: 14px;
  flex: 1;
  min-width: 0;
}
.pdf-icon {
  width: 44px;
  height: 44px;
  border-radius: 12px;
  background: var(--primary-light);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 20px;
  flex-shrink: 0;
  color: var(--primary);
}
.dataset-name {
  font-size: 15px;
  font-weight: 700;
  color: var(--text);
  margin-bottom: 4px;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}
.dataset-badges {
  display: flex;
  gap: 6px;
  flex-wrap: wrap;
}
.dataset-play-btn {
  width: 36px;
  height: 36px;
  border-radius: 50%;
  background: var(--primary-light);
  color: var(--primary);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 12px;
  transition: var(--transition);
  flex-shrink: 0;
}
.dataset-card:hover .dataset-play-btn {
  background: var(--primary);
  color: #fff;
}



/* ===== Badges ===== */
.badge {
  display: inline-flex; align-items: center; gap: 4px;
  padding: 3px 10px; border-radius: 50px;
  font-size: 12px; font-weight: 600; line-height: 1.4;
}
.badge-blue  { background: var(--primary-light); color: var(--primary); }
.badge-green { background: var(--success-bg); color: var(--success); border: 1px solid var(--success-border); }
.badge-red   { background: var(--danger-bg); color: var(--danger); border: 1px solid var(--danger-border); }
.badge-purple{ background: var(--accent-light); color: var(--accent); }
.badge-gray  { background: #F1F5F9; color: var(--text-3); }

/* ===== Buttons ===== */
.btn {
  display: inline-flex; align-items: center; justify-content: center;
  gap: 7px; padding: 9px 20px; border-radius: var(--radius-sm);
  font-size: 14px; font-weight: 600; cursor: pointer; border: none;
  transition: var(--transition); white-space: nowrap; text-decoration: none;
}
.btn-primary {
  background: var(--primary); color: #fff;
  box-shadow: 0 4px 14px var(--primary-glow);
}
.btn-primary:hover { background: var(--primary-dark); transform: translateY(-1px); box-shadow: 0 6px 20px var(--primary-glow); }
.btn-accent { background: var(--accent); color: #fff; box-shadow: 0 4px 14px rgba(124,92,252,0.25); }
.btn-accent:hover { filter: brightness(1.08); transform: translateY(-1px); }
.btn-ghost { background: #fff; color: var(--text-2); border: 1.5px solid var(--border); }
.btn-ghost:hover { border-color: var(--primary); color: var(--primary); background: var(--primary-light); }
.btn-danger { background: var(--danger); color: #fff; }
.btn-danger:hover { filter: brightness(1.08); }
.btn-success { background: var(--success); color: #fff; }
.btn-icon { background: var(--bg-hover); color: var(--text-2); border: 1.5px solid var(--border); border-radius: var(--radius-sm); width: 36px; height: 36px; padding: 0; }
.btn-icon:hover { border-color: var(--primary); color: var(--primary); }
.btn-lg { padding: 12px 28px; font-size: 15px; border-radius: 10px; }
.btn-sm { padding: 6px 14px; font-size: 13px; border-radius: 7px; }
.btn:disabled { opacity: 0.5; cursor: not-allowed; transform: none !important; }

/* ===== Feature cards ===== */
.feature-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(220px, 1fr)); gap: 14px; }
.feature-card {
  background: #fff; border: 1px solid var(--border);
  border-radius: var(--radius-lg); padding: 20px;
  display: flex; align-items: flex-start; gap: 14px;
  box-shadow: var(--shadow-sm); transition: var(--transition);
}
.feature-card:hover { box-shadow: var(--shadow); transform: translateY(-2px); }
.feature-icon {
  width: 42px; height: 42px; border-radius: 12px;
  display: flex; align-items: center; justify-content: center;
  font-size: 20px; flex-shrink: 0;
}
.feature-icon.blue { background: var(--primary-light); }
.feature-icon.green { background: var(--success-bg); }
.feature-icon.purple { background: var(--accent-light); }
.feature-icon.orange { background: var(--warning-bg); }
.feature-title { font-size: 14px; font-weight: 700; color: var(--primary); margin-bottom: 4px; }
.feature-desc { font-size: 12px; color: var(--text-3); line-height: 1.5; }

/* ===== Footer ===== */
.footer {
  text-align: center; padding: 28px 0;
  border-top: 1px solid var(--border);
  color: var(--text-3); font-size: 13px;
  margin-top: 40px;
}

/* ===== Modal ===== */
.modal-overlay {
  position: fixed; inset: 0; z-index: 200;
  background: rgba(15,23,42,0.45);
  backdrop-filter: blur(6px);
  display: flex; align-items: center; justify-content: center;
  padding: 20px; animation: fadeIn 0.2s ease;
}
@keyframes fadeIn { from { opacity: 0; } to { opacity: 1; } }
.modal {
  background: #fff; border-radius: var(--radius-xl);
  padding: 36px; width: 100%; max-width: 460px;
  box-shadow: var(--shadow-lg);
  animation: slideUp 0.28s cubic-bezier(0.34,1.56,0.64,1);
}
@keyframes slideUp { from { transform: translateY(30px); opacity: 0; } to { transform: translateY(0); opacity: 1; } }
.modal-icon { font-size: 40px; margin-bottom: 14px; }
.modal h2 { font-size: 22px; font-weight: 800; margin-bottom: 6px; color: var(--text); }
.modal-sub { font-size: 14px; color: var(--text-2); margin-bottom: 24px; }

/* ===== Forms ===== */
.form-group { margin-bottom: 16px; }
.form-label { display: block; font-size: 13px; font-weight: 600; color: var(--text-2); margin-bottom: 7px; }
.form-control {
  width: 100%; padding: 9px 13px;
  background: var(--bg-input); border: 1.5px solid var(--border);
  border-radius: var(--radius-sm); color: var(--text);
  font-size: 14px; font-family: inherit; transition: var(--transition);
}
.form-control:focus { outline: none; border-color: var(--primary); background: #fff; box-shadow: 0 0 0 3px var(--primary-glow); }
select.form-control { cursor: pointer; }

/* ===== Quiz layout ===== */
.quiz-page-wrap {
  display: grid;
  grid-template-columns: 1fr 264px;
  gap: 20px;
  padding: 24px 0 48px;
  align-items: start;
}
.quiz-sidebar { position: sticky; top: 80px; }

/* Timer */
.timer-card {
  background: #fff; border: 1.5px solid var(--border);
  border-radius: var(--radius-lg); padding: 20px; text-align: center;
  box-shadow: var(--shadow-sm);
}
.timer-label { font-size: 11px; font-weight: 600; color: var(--text-3); text-transform: uppercase; letter-spacing: 1px; margin-bottom: 8px; }
.timer-display {
  font-size: 46px; font-weight: 900; font-variant-numeric: tabular-nums;
  color: var(--primary); line-height: 1; margin: 6px 0 4px;
  letter-spacing: 0;
}
.timer-display.warning { color: var(--warning); }
.timer-display.danger { color: var(--danger); animation: pulse 1s infinite; }
@keyframes pulse { 0%,100%{opacity:1} 50%{opacity:.55} }

/* Q nav grid */
.q-nav { display: grid; grid-template-columns: repeat(5,1fr); gap: 5px; margin-top: 14px; }
.q-nav-btn {
  aspect-ratio: 1; border-radius: 7px;
  border: 1.5px solid var(--border); background: var(--bg);
  color: var(--text-3); font-size: 11px; font-weight: 700;
  cursor: pointer; transition: var(--transition);
  display: flex; align-items: center; justify-content: center;
}
.q-nav-btn:hover { border-color: var(--primary); color: var(--primary); background: var(--primary-light); }
.q-nav-btn.answered { background: var(--success-bg); border-color: var(--success); color: var(--success); }
.q-nav-btn.current { background: var(--primary); border-color: var(--primary); color: #fff; }
.q-nav-btn.practice-correct { background: #DCFCE7; border-color: #16A34A; color: #16A34A; }
.q-nav-btn.practice-wrong { background: #FEE2E2; border-color: #EF4444; color: #EF4444; }
.q-nav-btn.practice-correct.current { background: #16A34A; color: #fff; }
.q-nav-btn.practice-wrong.current { background: #EF4444; color: #fff; }
.badge-red { background: #FEE2E2; color: #DC2626; }
.badge-green { background: #DCFCE7; color: #16A34A; }
.practice-next-btn { font-size: 14px !important; padding: 8px 20px !important; }
@keyframes fadeIn { from { opacity: 0; transform: translateY(4px); } to { opacity: 1; transform: translateY(0); } }

/* Question card */
.question-card {
  background: #fff; border: 1px solid var(--border);
  border-radius: var(--radius-xl); padding: 32px;
  box-shadow: var(--shadow-sm); animation: fadeUp 0.25s ease;
}
@keyframes fadeUp { from { opacity:0; transform:translateY(12px); } to { opacity:1; transform:translateY(0); } }
.q-meta {
  display: flex; align-items: center; gap: 8px;
  margin-bottom: 18px; flex-wrap: wrap;
}
.q-num-label { font-size: 13px; font-weight: 600; color: var(--text-3); }
.q-text { font-size: 17px; font-weight: 600; color: var(--text); line-height: 1.65; margin-bottom: 24px; }

/* Options */
.options { display: flex; flex-direction: column; gap: 10px; }
.option-btn {
  display: flex; align-items: flex-start; gap: 12px;
  padding: 14px 18px; background: var(--bg);
  border: 2px solid var(--border); border-radius: var(--radius);
  cursor: pointer; transition: var(--transition);
  text-align: left; width: 100%; color: var(--text);
}
.option-btn:hover:not(:disabled) {
  border-color: var(--primary); background: var(--primary-light);
  transform: translateX(3px);
}
.option-btn.selected { border-color: var(--primary); background: var(--primary-light); }
.option-btn.correct { border-color: var(--success); background: var(--success-bg); }
.option-btn.wrong { border-color: var(--danger); background: var(--danger-bg); }
.option-letter {
  min-width: 28px; height: 28px; border-radius: 8px;
  background: var(--border); border: 1.5px solid var(--border-2);
  display: flex; align-items: center; justify-content: center;
  font-size: 12px; font-weight: 800; flex-shrink: 0;
  color: var(--text-2); transition: var(--transition);
}
.option-btn.selected .option-letter { background: var(--primary); border-color: var(--primary); color: #fff; }
.option-btn.correct .option-letter { background: var(--success); border-color: var(--success); color: #fff; }
.option-btn.wrong .option-letter { background: var(--danger); border-color: var(--danger); color: #fff; }
.option-text { font-size: 14px; line-height: 1.55; padding-top: 3px; }

/* Explanation */
.explanation-box {
  margin-top: 20px; padding: 18px;
  background: var(--success-bg); border: 1px solid var(--success-border);
  border-radius: var(--radius); animation: fadeUp 0.25s ease;
}
.explanation-label {
  font-size: 12px; font-weight: 700; color: var(--success);
  text-transform: uppercase; letter-spacing: .8px;
  margin-bottom: 8px; display: flex; align-items: center; gap: 6px;
}
.explanation-text { font-size: 14px; color: #166534; line-height: 1.7; }

/* Q controls */
.q-controls {
  display: flex; align-items: center; justify-content: space-between;
  margin-top: 24px; padding-top: 20px; border-top: 1px solid var(--border);
  gap: 12px;
}

/* ===== Progress card ===== */
.progress-card {
  background: #fff; border: 1px solid var(--border);
  border-radius: var(--radius-lg); padding: 16px;
  box-shadow: var(--shadow-sm); margin-top: 14px;
}

/* ===== Result ===== */
.result-hero { text-align: center; padding: 48px 0 32px; }
.score-wrap {
  width: 150px; height: 150px; margin: 0 auto 20px;
  position: relative;
}
.score-svg { width: 100%; height: 100%; transform: rotate(-90deg); }
.score-track { fill: none; stroke: var(--border); stroke-width: 10; }
.score-fill { fill: none; stroke: var(--primary); stroke-width: 10; stroke-linecap: round; transition: stroke-dashoffset 1.2s ease; }
.score-center {
  position: absolute; inset: 0;
  display: flex; flex-direction: column; align-items: center; justify-content: center;
}
.score-pct { font-size: 30px; font-weight: 900; color: var(--primary); }
.score-lbl { font-size: 11px; color: var(--text-3); font-weight: 600; }
.result-title { font-size: 28px; font-weight: 900; color: var(--text); }
.result-sub { font-size: 15px; color: var(--text-2); margin-top: 6px; }

.stats-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(140px, 1fr)); gap: 12px; margin: 28px 0; }
.stats-cell {
  background: #fff; border: 1px solid var(--border);
  border-radius: var(--radius); padding: 18px; text-align: center;
  box-shadow: var(--shadow-sm);
}
.stats-cell-val { font-size: 30px; font-weight: 900; margin-bottom: 4px; }
.stats-cell-lbl { font-size: 12px; color: var(--text-3); font-weight: 500; }
.stats-cell.c-blue  .stats-cell-val { color: var(--primary); }
.stats-cell.c-green .stats-cell-val { color: var(--success); }
.stats-cell.c-red   .stats-cell-val { color: var(--danger); }
.stats-cell.c-orange .stats-cell-val { color: var(--warning); }

/* ===== Admin ===== */
.log-box {
  background: #F8FAFF; border: 1px solid var(--border);
  border-radius: var(--radius); padding: 16px;
  max-height: 320px; overflow-y: auto;
  font-family: 'JetBrains Mono', 'Courier New', monospace; font-size: 12.5px;
}
.log-entry { padding: 3px 0; border-bottom: 1px solid transparent; }
.log-entry.success { color: #15803D; }
.log-entry.error   { color: var(--danger); }
.log-entry.info    { color: var(--text-3); }
.log-entry.start   { color: var(--primary); font-weight: 600; }
.log-entry.done    { color: var(--accent); font-weight: 700; }

/* Slider */
input[type=range] {
  flex: 1; height: 5px; border-radius: 3px;
  accent-color: var(--primary); cursor: pointer;
}

/* ===== Toast ===== */
.toast-container { position: fixed; bottom: 20px; right: 20px; z-index: 500; display: flex; flex-direction: column; gap: 8px; }
.toast {
  padding: 12px 18px; border-radius: var(--radius);
  font-size: 14px; font-weight: 500;
  min-width: 240px; max-width: 340px;
  display: flex; align-items: center; gap: 10px;
  box-shadow: var(--shadow-lg); animation: toastIn 0.3s ease;
  background: #fff; border-left: 4px solid var(--primary); color: var(--text);
}
@keyframes toastIn { from { transform: translateX(110%); opacity: 0; } to { transform: translateX(0); opacity: 1; } }
.toast-success { border-color: var(--success); }
.toast-error   { border-color: var(--danger); }
.toast-info    { border-color: var(--primary); }

/* ===== Utility ===== */
.d-flex { display: flex; }
.align-center { align-items: center; }
.justify-between { justify-content: space-between; }
.gap-6 { gap: 6px; } .gap-8 { gap: 8px; } .gap-12 { gap: 12px; } .gap-16 { gap: 16px; }
.flex-1 { flex: 1; }
.text-center { text-align: center; }
.mt-8 { margin-top: 8px; } .mt-12 { margin-top: 12px; } .mt-16 { margin-top: 16px; } .mt-24 { margin-top: 24px; }
.mb-8 { margin-bottom: 8px; } .mb-16 { margin-bottom: 16px; }
.fw-bold { font-weight: 700; } .fw-800 { font-weight: 800; }
.text-primary { color: var(--primary); }
.text-muted { color: var(--text-3); }
.text-sm { font-size: 13px; }

/* Spinner */
.spinner {
  width: 18px; height: 18px; border-radius: 50%;
  border: 2.5px solid rgba(79,110,247,0.25);
  border-top-color: var(--primary);
  animation: spin 0.75s linear infinite; flex-shrink: 0;
}
.spinner.white { border-color: rgba(255,255,255,0.3); border-top-color: #fff; }
@keyframes spin { to { transform: rotate(360deg); } }

.loading-state {
  display: flex; flex-direction: column; align-items: center;
  justify-content: center; padding: 60px 20px; gap: 14px;
  color: var(--text-3);
}
.loading-state .spinner { width: 32px; height: 32px; }

.empty-state { text-align: center; padding: 60px 20px; color: var(--text-3); }
.empty-state .icon { font-size: 44px; margin-bottom: 14px; }
.empty-state h3 { font-size: 17px; color: var(--text-2); margin-bottom: 6px; }

/* ===== RESPONSIVE ===== */
@media (max-width: 768px) {
  .hero {
    grid-template-columns: 1fr;
    padding: 32px 0 28px;
    gap: 28px;
  }
  .hero-illustration { display: none; }
  .hero h1 { font-size: 2rem; }
  .hero-stats { max-width: 100%; gap: 7px; }
  .stat-pill { padding: 9px 10px; }
  .stat-num { font-size: 20px; }

  .quiz-page-wrap {
    grid-template-columns: 1fr;
    padding: 16px 0 40px;
  }
  .quiz-sidebar { position: static; order: -1; }
  .timer-card { display: flex; align-items: center; gap: 16px; text-align: left; }
  .timer-display { font-size: 32px; }
  .q-nav { grid-template-columns: repeat(7, 1fr); }
  .question-card { padding: 20px; }
  .q-text { font-size: 15px; }

  .card-grid { grid-template-columns: 1fr; }
  .feature-grid { grid-template-columns: 1fr 1fr; }
  .stats-grid { grid-template-columns: repeat(2, 1fr); }
  .modal { padding: 24px; }

  .section-header { flex-direction: column; }
  .q-controls { flex-wrap: wrap; gap: 8px; }
}

@media (max-width: 480px) {
  .container { padding: 0 14px; }
  .hero h1 { font-size: 1.75rem; }
  .hero-stats { grid-template-columns: 1fr; }
  .stat-pill { justify-content: flex-start; }
  .feature-grid { grid-template-columns: 1fr; }
  .stats-grid { grid-template-columns: repeat(2, 1fr); }
  .modal { padding: 20px; border-radius: var(--radius-lg); }
  .question-card { padding: 16px; border-radius: var(--radius-lg); }
  .result-hero { padding: 32px 0 20px; }
  .navbar-inner { padding: 0 10px; gap: 8px; }
  .nav-brand-text { font-size: 16px; font-weight: 800; display: block; }
  .nav-text { display: none; }
  .nav-link { padding: 8px 10px; }
}

/* ===== Pill / Option selector (thay thế dropdown trên mobile) ===== */
.pill-group {
  display: flex; flex-wrap: wrap; gap: 8px;
}
.pill-btn {
  padding: 8px 16px; border-radius: 50px;
  border: 1.5px solid var(--border);
  background: var(--bg-input); color: var(--text-2);
  font-size: 13px; font-weight: 600; cursor: pointer;
  transition: var(--transition); white-space: nowrap;
  font-family: inherit;
}
.pill-btn:hover { border-color: var(--primary); color: var(--primary); background: var(--primary-light); }
.pill-btn.active {
  background: var(--primary); color: #fff;
  border-color: var(--primary);
  box-shadow: 0 3px 10px var(--primary-glow);
}
.pill-btn.pill-sm { padding: 5px 12px; font-size: 12px; }

/* Modal bottom-sheet trên mobile */
@media (max-width: 520px) {
  .modal-overlay {
    align-items: flex-end;
    padding: 0;
  }
  .modal {
    border-radius: var(--radius-xl) var(--radius-xl) 0 0;
    max-width: 100%;
    padding: 24px 20px 32px;
    max-height: 92vh;
    overflow-y: auto;
    animation: slideSheet 0.32s cubic-bezier(0.34,1.2,0.64,1);
  }
  @keyframes slideSheet {
    from { transform: translateY(100%); }
    to   { transform: translateY(0); }
  }
  /* Drag handle indicator */
  .modal::before {
    content: '';
    display: block;
    width: 40px; height: 4px;
    background: var(--border-2);
    border-radius: 2px;
    margin: 0 auto 20px;
  }
  .pill-btn { padding: 10px 18px; font-size: 14px; }
}

/* ===== Top câu sai section ===== */
.wrong-stats-section { margin-bottom: 40px; }
.wrong-rank-list { display: flex; flex-direction: column; gap: 10px; }
.wrong-rank-item {
  display: flex; align-items: flex-start; gap: 14px;
  background: #fff; border: 1px solid var(--border);
  border-radius: var(--radius-lg); padding: 14px 18px;
  box-shadow: var(--shadow-sm); transition: var(--transition);
  cursor: pointer;
}
.wrong-rank-item:hover { box-shadow: var(--shadow); border-color: var(--danger); transform: translateX(3px); }
.wrong-rank-num {
  min-width: 36px; height: 36px; border-radius: 10px;
  display: flex; align-items: center; justify-content: center;
  font-size: 14px; font-weight: 900; flex-shrink: 0;
  background: var(--danger-bg); color: var(--danger);
  border: 1.5px solid var(--danger-border);
}
.wrong-rank-num.top1 { background: #FEF9C3; color: #854D0E; border-color: #FDE047; font-size: 16px; }
.wrong-rank-num.top2 { background: #F1F5F9; color: #475569; border-color: var(--border-2); }
.wrong-rank-num.top3 { background: #FFF7ED; color: #9A3412; border-color: #FED7AA; }
.wrong-rank-q { font-size: 13px; font-weight: 600; color: var(--text); line-height: 1.5; flex: 1; }
.wrong-rank-meta { margin-top: 4px; font-size: 12px; color: var(--text-3); }
.wrong-rank-count {
  flex-shrink: 0; padding: 3px 10px;
  background: var(--danger-bg); color: var(--danger);
  border-radius: 50px; font-size: 12px; font-weight: 700;
  border: 1px solid var(--danger-border);
  white-space: nowrap;
}

/* In result page: compact wrong list */
.wrong-mini-list { display: flex; flex-direction: column; gap: 8px; margin-top: 12px; }
.wrong-mini-item {
  display: flex; align-items: center; gap: 10px;
  padding: 10px 14px; background: var(--danger-bg);
  border: 1px solid var(--danger-border);
  border-radius: var(--radius); font-size: 13px;
}
.wrong-mini-badge {
  min-width: 24px; height: 24px; border-radius: 6px;
  background: var(--danger); color: #fff;
  display: flex; align-items: center; justify-content: center;
  font-size: 11px; font-weight: 800; flex-shrink: 0;
}

/* ===== Hero Visual (CSS animated) ===== */
.hero-visual {
  position: relative;
  width: 100%; max-width: 420px;
  height: 420px;
  display: flex; align-items: center; justify-content: center;
}

/* Blob gradient background */
.blob {
  position: absolute;
  inset: 0;
  border-radius: 40% 60% 55% 45% / 45% 40% 60% 55%;
  background: linear-gradient(135deg, #c7d7fe 0%, #ddd6fe 50%, #ede9fe 100%);
  animation: blobMorph 8s ease-in-out infinite alternate;
  box-shadow: 0 8px 48px rgba(124,92,252,0.18);
}
@keyframes blobMorph {
  0%   { border-radius: 40% 60% 55% 45% / 45% 40% 60% 55%; }
  33%  { border-radius: 55% 45% 40% 60% / 60% 55% 45% 40%; }
  66%  { border-radius: 45% 55% 60% 40% / 50% 60% 40% 50%; }
  100% { border-radius: 60% 40% 45% 55% / 40% 55% 60% 45%; }
}

/* Dot grid */
.dots {
  position: absolute; inset: 0;
  background-image: radial-gradient(circle, rgba(79,110,247,0.18) 1.5px, transparent 1.5px);
  background-size: 22px 22px;
  border-radius: 50%;
  mask-image: radial-gradient(circle, black 60%, transparent 100%);
  -webkit-mask-image: radial-gradient(circle, black 60%, transparent 100%);
}

/* Quiz card center */
.quiz-card {
  position: relative; z-index: 2;
  background: #fff;
  border-radius: 18px;
  padding: 20px 22px;
  width: 200px;
  box-shadow: 0 12px 40px rgba(79,110,247,0.18), 0 4px 12px rgba(0,0,0,0.08);
  animation: cardFloat 4s ease-in-out infinite;
}
@keyframes cardFloat {
  0%,100% { transform: translateY(0); }
  50%      { transform: translateY(-10px); }
}

/* Check mark top */
.quiz-card .check {
  width: 30px; height: 30px; border-radius: 50%;
  background: linear-gradient(135deg, var(--primary), var(--accent));
  display: flex; align-items: center; justify-content: center;
  color: #fff; font-size: 13px; margin-bottom: 12px;
  box-shadow: 0 4px 12px rgba(79,110,247,0.35);
}

/* Skeleton lines (question text placeholder) */
.quiz-card .line {
  height: 7px; border-radius: 4px;
  background: var(--bg); margin-bottom: 10px;
}
.quiz-card .line.long  { width: 100%; }
.quiz-card .line.short { width: 65%; margin-bottom: 14px; }

/* Answer rows */
.answer-row {
  display: flex; align-items: center; gap: 9px;
  padding: 7px 10px;
  border-radius: 8px;
  border: 1.5px solid var(--border);
  margin-bottom: 7px;
  background: var(--bg);
  transition: var(--transition);
}
.answer-row:last-child { margin-bottom: 0; }
.answer-row.active {
  background: var(--primary-light);
  border-color: var(--primary);
}
.answer-row.active .answer-dot {
  background: var(--primary);
  color: #fff;
}
.answer-dot {
  width: 20px; height: 20px;
  border-radius: 50%;
  background: var(--border);
  display: flex; align-items: center; justify-content: center;
  font-size: 10px; font-weight: 800; color: var(--text-2);
  flex-shrink: 0;
}

/* Floating badges */
.floating {
  position: absolute; z-index: 3;
  background: #fff;
  border-radius: 14px;
  display: flex; align-items: center; justify-content: center;
  box-shadow: 0 6px 24px rgba(0,0,0,0.10);
  animation: floatDrift 6s ease-in-out infinite;
}
.floating.brain {
  width: 52px; height: 52px;
  top: 18px; right: 16px;
  font-size: 22px; color: var(--accent);
  animation-delay: 0s;
  background: linear-gradient(135deg, #f0ebff, #fff);
}
.floating.chart {
  width: 48px; height: 48px;
  bottom: 28px; right: 12px;
  font-size: 20px; color: var(--primary);
  animation-delay: 2s;
  background: linear-gradient(135deg, #eef1ff, #fff);
}
.floating.pie {
  width: 54px; height: 54px;
  bottom: 20px; left: 8px;
  animation-delay: 1s;
  background: linear-gradient(135deg, #fff7ed, #fff);
  padding: 10px;
}
@keyframes floatDrift {
  0%,100% { transform: translateY(0) rotate(0deg); }
  33%      { transform: translateY(-8px) rotate(3deg); }
  66%      { transform: translateY(4px) rotate(-2deg); }
}

/* Pie shape (CSS pie chart) */
.pie-shape {
  width: 32px; height: 32px;
  border-radius: 50%;
  background: conic-gradient(
    var(--primary) 0deg 130deg,
    var(--accent)  130deg 230deg,
    var(--warning) 230deg 310deg,
    #F87171        310deg 360deg
  );
  box-shadow: 0 2px 8px rgba(79,110,247,0.25);
  animation: pieSpin 12s linear infinite;
}
@keyframes pieSpin {
  from { transform: rotate(0deg); }
  to   { transform: rotate(360deg); }
}

/* Hide hero-visual on mobile (use blob only) */
@media (max-width: 768px) {
  .hero-visual { display: none; }
}