:root {
  --bg-color: #0b0f19;
  --glass: rgba(23, 32, 53, 0.72);
  --border: rgba(255, 255, 255, 0.08);
  --primary: #00f2fe;
  --primary-glow: 0 0 20px rgba(0, 242, 254, 0.28);
  --text: #ffffff;
  --text-dim: #94a3b8;
  --yellow: #facc15;
  --success: #10b981;
  --danger: #ef4444;
  --card-border: rgba(255,255,255,0.06);
}
body.light-mode {
  --bg-color: #f1f5f9;
  --glass: rgba(255, 255, 255, 0.84);
  --border: rgba(0, 0, 0, 0.05);
  --primary: #0ea5e9;
  --text: #1e293b;
  --text-dim: #64748b;
  --card-border: rgba(0,0,0,0.05);
}
* { margin:0; padding:0; box-sizing:border-box; -webkit-tap-highlight-color: transparent; }
html, body { height:100%; }
body {
  font-family: 'Segoe UI', 'BPG Arial', sans-serif;
  background: radial-gradient(circle at top, rgba(0,242,254,0.08), transparent 25%), var(--bg-color);
  color: var(--text);
  overflow:hidden;
  transition: background 0.3s ease;
}
button, input { font: inherit; }
button { border:none; cursor:pointer; }
.glass { background: var(--glass); backdrop-filter: blur(14px); -webkit-backdrop-filter: blur(14px); border:1px solid var(--border); box-shadow: 0 10px 28px rgba(0,0,0,0.18); }
.app-container { max-width: 520px; margin:0 auto; height:100dvh; display:flex; flex-direction:column; position:relative; }
header { display:flex; justify-content:space-between; align-items:center; padding:15px 18px; margin:10px; border-radius:22px; flex-shrink:0; }
header h1 { font-size:1.15rem; letter-spacing:0.3px; }
main { flex:1; overflow-y:auto; padding:10px 15px 110px 15px; scrollbar-width:none; }
main::-webkit-scrollbar { display:none; }
.sidebar { position:fixed; top:0; width:82%; max-width:320px; height:100dvh; z-index:3000; transition: transform .35s ease; display:flex; flex-direction:column; }
.sidebar-left { left:0; transform:translateX(-105%); border-radius:0 24px 24px 0; }
.sidebar-right { right:0; transform:translateX(105%); border-radius:24px 0 0 24px; }
.sidebar.active { transform:translateX(0); }
.sidebar-header { padding:22px 20px; border-bottom:1px solid var(--border); display:flex; justify-content:space-between; align-items:center; }
.sidebar-scroll-area { flex:1; overflow-y:auto; padding:15px; }
.sidebar-list { list-style:none; }
.sidebar-list li { padding:14px 15px; border-radius:14px; margin-bottom:8px; cursor:pointer; display:flex; align-items:center; gap:12px; transition:.2s; background: rgba(255,255,255,0.03); }
.sidebar-list li:hover { transform: translateX(2px); background: rgba(0,242,254,0.10); color: var(--primary); }
.sidebar-list li.danger-zone:hover { background: rgba(239,68,68,0.14); color: var(--danger); }
.overlay { position:fixed; inset:0; background:rgba(0,0,0,0.58); z-index:2500; display:none; backdrop-filter: blur(4px); }
.overlay.active { display:block; }
.view { display:none; animation: slideUp .25s ease-out; }
.view.active { display:block; }
@keyframes slideUp { from { opacity:0; transform: translateY(14px); } to { opacity:1; transform: translateY(0); } }
.card-scene { perspective:1200px; height:350px; margin:10px 0 20px; }
.card { width:100%; height:100%; position:relative; transform-style:preserve-3d; transition:.65s cubic-bezier(.2,.8,.2,1); cursor:pointer; }
.card.flipped { transform: rotateY(180deg); }
.card-face { position:absolute; inset:0; backface-visibility:hidden; display:flex; flex-direction:column; align-items:center; justify-content:center; padding:22px; border-radius:30px; text-align:center; border:1px solid var(--card-border); }
.card-back { transform: rotateY(180deg); }
.card-topline { display:flex; width:100%; justify-content:space-between; align-items:center; margin-bottom:auto; }
.main-word { font-size:2.6rem; font-weight:800; line-height:1.1; margin-top:10px; }
.phonetic { color: var(--primary); font-size:1.05rem; margin-top:8px; font-weight:500; }
.hint { margin-top:auto; color:var(--text-dim); font-size:.9rem; }
.translation { font-size:2rem; color:var(--primary); font-weight:800; }
.example-box { width:100%; margin-top:18px; padding:15px; border-radius:18px; background: rgba(255,255,255,0.04); }
.ex-ger { font-size:1.05rem; font-weight:700; }
.phonetic-sm { color:var(--primary); font-size:.95rem; margin:6px 0; }
.ex-geo { color:var(--text-dim); font-size:.95rem; }
.controls { display:flex; justify-content:space-around; align-items:center; gap:12px; }
.ctrl-btn, .icon-btn, .nav-item, .pag-btn, .badge-btn, .primary-btn { transition:.25s ease; }
.ctrl-btn { width:60px; height:60px; border-radius:50%; display:flex; align-items:center; justify-content:center; font-size:1.2rem; color:var(--text); background:transparent; }
.ctrl-btn.primary { width:76px; height:76px; border-radius:50%; background:var(--primary); color:#001018; box-shadow:var(--primary-glow); font-size:1.45rem; }
.ctrl-btn:hover, .icon-btn:hover, .nav-item:hover, .pag-btn:hover, .badge-btn:hover, .primary-btn:hover { transform: translateY(-1px); }
.ctrl-btn:active, .icon-btn:active, .nav-item:active, .pag-btn:active, .badge-btn:active, .primary-btn:active { transform: scale(.96); }
.icon-btn { width:42px; height:42px; border-radius:50%; display:inline-flex; align-items:center; justify-content:center; color:var(--text); background: rgba(255,255,255,0.05); }
.icon-btn.soft { width:38px; height:38px; background: rgba(0,242,254,0.10); color:var(--primary); }
.badge { background: rgba(0,242,254,0.10); color: var(--primary); padding:5px 14px; border-radius:20px; font-weight:700; font-size:.82rem; border:1px solid var(--border); }
.badge.ghost { color:var(--text-dim); background: rgba(255,255,255,0.04); }
.toast { position:fixed; top:-120px; left:50%; transform:translateX(-50%); padding:14px 20px; border-radius:999px; z-index:9999; transition:.45s ease; font-weight:700; box-shadow: 0 10px 30px rgba(0,0,0,.3); max-width:90vw; text-align:center; }
.toast.active { top:20px; }
.bottom-nav { position:absolute; bottom:0; width:100%; display:flex; justify-content:space-around; padding:12px 10px 28px 10px; border-radius:28px 28px 0 0; z-index:1000; }
.nav-item { background:none; color:var(--text-dim); display:flex; flex-direction:column; align-items:center; gap:4px; flex:1; }
.nav-item.active { color:var(--primary); }
.nav-item i { font-size:1.2rem; }
.nav-item span { font-size:.72rem; font-weight:700; }
.list-container { display:flex; flex-direction:column; gap:12px; }
.list-item { padding:16px; border-radius:20px; display:flex; justify-content:space-between; align-items:center; gap:14px; }
.list-item .meta { color:var(--text-dim); font-size:.88rem; margin-top:4px; }
.search-box { display:flex; align-items:center; padding:12px 14px; border-radius:16px; gap:10px; width:100%; }
.search-box input { background:none; border:none; color:var(--text); outline:none; flex:1; font-size:1rem; }
.clear-btn { background:none; color:var(--text-dim); }
.pagination { padding:15px 0; gap:12px; }
.pag-btn { width:44px; height:44px; border-radius:50%; background:var(--glass); color:var(--text); }
.pag-btn:disabled { opacity:.35; cursor:not-allowed; }
.cat-header { display:flex; justify-content:space-between; align-items:center; padding:16px 18px; border-radius:22px; gap:14px; }
.cat-header h2 { font-size:1.15rem; }
.cat-header p { font-size:.85rem; margin-top:4px; }
.badge-btn, .primary-btn { padding:12px 16px; border-radius:14px; font-weight:800; }
.badge-btn { background: rgba(0,242,254,0.10); color:var(--primary); }
.primary-btn { background:var(--primary); color:#001018; box-shadow:var(--primary-glow); }
.text-center { text-align:center; }
.text-dim { color:var(--text-dim); }
.text-primary { color:var(--primary); }
.mt-10 { margin-top:10px; }
.mt-20 { margin-top:20px; }
.mb-10 { margin-bottom:10px; }
.mb-20 { margin-bottom:20px; }
.flex-center { display:flex; justify-content:center; align-items:center; }
.gap-10 { gap:10px; }
.toolbar-row { display:flex; justify-content:space-between; align-items:center; gap:10px; margin-bottom:10px; }
.mini-stats { display:grid; grid-template-columns:repeat(3,1fr); gap:10px; padding:14px; border-radius:22px; }
.mini-stats > div { display:flex; flex-direction:column; align-items:center; gap:6px; text-align:center; padding:10px 4px; }
.mini-stats strong { font-size:1.05rem; }
.mini-stats span { color:var(--text-dim); font-size:.8rem; }
.profile-card { padding:18px; border-radius:24px; }
.profile-header { display:flex; flex-direction:column; align-items:center; gap:10px; margin-bottom:14px; }
.avatar-circle { width:74px; height:74px; border-radius:50%; display:flex; align-items:center; justify-content:center; background: rgba(0,242,254,0.12); color:var(--primary); font-size:1.7rem; }
.stats-grid { display:grid; grid-template-columns:repeat(2, 1fr); gap:12px; }
.stat-item { padding:14px; border-radius:18px; text-align:center; }
.stat-item h4 { font-size:1.2rem; margin-bottom:4px; }
.stat-item span { color:var(--text-dim); font-size:.8rem; }
.progress-section { margin-top:16px; }
.progress-info { display:flex; justify-content:space-between; margin-bottom:8px; color:var(--text-dim); }
.progress-bar-bg { width:100%; height:10px; background:rgba(255,255,255,0.08); border-radius:999px; overflow:hidden; }
.progress-bar-fill { height:100%; width:0%; background: linear-gradient(90deg, var(--primary), var(--success)); border-radius:999px; transition: width .35s ease; }
.category-progress { margin-top:14px; display:flex; flex-direction:column; gap:12px; }
.category-progress-item { padding:14px; border-radius:18px; }
.category-progress-top { display:flex; justify-content:space-between; gap:10px; margin-bottom:8px; }
.category-progress-name { font-weight:700; }
.lesson-grid { display:grid; gap:12px; }
.lesson-card { padding:16px; border-radius:20px; }
.lesson-card h3 { margin-bottom:8px; }
.lesson-card p { color:var(--text-dim); line-height:1.55; font-size:.95rem; }
.quiz-container { padding:18px; border-radius:24px; }
.quiz-header { display:flex; gap:8px; flex-wrap:wrap; justify-content:space-between; margin-bottom:12px; }
.quiz-sound-row { display:flex; justify-content:space-between; align-items:center; margin-bottom:10px; }
.quiz-q { text-align:center; font-size:1.7rem; margin:8px 0 16px; }
.quiz-opts { display:grid; gap:10px; }
.quiz-option { width:100%; padding:14px 12px; border-radius:16px; color:var(--text); text-align:left; background:rgba(255,255,255,0.04); border:1px solid var(--border); }
.quiz-option.correct { background: rgba(16,185,129,0.18); color: var(--text); border-color: rgba(16,185,129,0.35); }
.quiz-option.wrong { background: rgba(239,68,68,0.18); color: var(--text); border-color: rgba(239,68,68,0.38); }
.answer-feedback { margin-top:14px; padding:12px 14px; border-radius:16px; min-height: 20px; color: var(--text); background: rgba(255,255,255,0.04); border:1px dashed var(--border); }
.feedback-good { color: var(--success); }
.feedback-bad { color: var(--danger); }
.feedback-neutral { color: var(--text-dim); }
.dropzone { min-height:74px; border-radius:20px; padding:12px; display:flex; flex-wrap:wrap; gap:10px; align-items:center; }
.word-pool { display:flex; flex-wrap:wrap; gap:10px; margin-top:14px; }
.word-chip { padding:9px 13px; border-radius:12px; background:rgba(255,255,255,0.05); cursor:pointer; border:1px solid var(--border); }
.word-chip.used { opacity:.35; }
.answer-chip { padding:9px 13px; border-radius:12px; background:rgba(0,242,254,0.10); color:var(--text); border:1px solid rgba(0,242,254,0.16); }
.section-note { display:flex; gap:10px; align-items:flex-start; padding:14px; border-radius:18px; color:var(--text-dim); }
.confetti-layer { position:fixed; inset:0; pointer-events:none; overflow:hidden; z-index:9998; }
.confetti { position:absolute; width:8px; height:14px; border-radius:3px; opacity:0; animation: confetti-fall 1200ms ease-out forwards; }
@keyframes confetti-fall { 0% { transform: translateY(-20px) rotate(0deg); opacity:1; } 100% { transform: translateY(100vh) rotate(720deg); opacity:0; } }
@media (max-width: 420px) {
  .main-word { font-size:2.25rem; }
  .translation { font-size:1.7rem; }
  .quiz-q { font-size:1.45rem; }
  .mini-stats { grid-template-columns:1fr 1fr 1fr; }
}