@import "https://fonts.googleapis.com/css2?family=Inter:wght@300;400;500;600;700;800;900&family=Noto+Sans+SC:wght@400;500;700;900&family=Outfit:wght@400;600;700;800;900&family=Plus+Jakarta+Sans:wght@400;500;600;700;800&display=swap";:root{--bg-dark:#070a12;--bg-card:#121a2fb3;--bg-card-hover:#1c2744d9;--border-color:#ffffff14;--border-active:#00e67666;--primary-jade:#00e676;--primary-jade-glow:#00e67640;--accent-gold:#ffc107;--accent-gold-glow:#ffc1074d;--accent-cyan:#00e5ff;--accent-crimson:#ff3d00;--text-main:#f8fafc;--text-muted:#94a3b8;--text-sub:#cbd5e1;--font-body:"Plus Jakarta Sans", "Inter", -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;--font-heading:"Outfit", "Plus Jakarta Sans", sans-serif;--font-hanzi:"Noto Sans SC", "Microsoft YaHei", "PingFang SC", sans-serif;--shadow-glow:0 8px 32px 0 #0000005e;--glass-backdrop:blur(16px) saturate(180%)}*{box-sizing:border-box;-webkit-tap-highlight-color:transparent;margin:0;padding:0;font-family:inherit}body{background-color:var(--bg-dark);color:var(--text-main);font-family:var(--font-body);-webkit-font-smoothing:antialiased;-moz-osx-font-smoothing:grayscale;text-rendering:optimizelegibility;background-image:radial-gradient(at 0 0,#00e67614 0,#0000 50%),radial-gradient(at 100% 0,#00e5ff14 0,#0000 50%),radial-gradient(at 50% 100%,#ffc1070d 0,#0000 50%);background-attachment:fixed;min-height:100vh;line-height:1.5;overflow-x:hidden}input,select,textarea,button,option{-webkit-font-smoothing:antialiased;font-family:var(--font-body)!important}select option{padding:10px;font-size:.95rem;color:#f8fafc!important;background-color:#0f172a!important}::-webkit-scrollbar{width:6px}::-webkit-scrollbar-track{background:#0f172a99}::-webkit-scrollbar-thumb{background:#ffffff26;border-radius:4px}.app-container{flex-direction:column;min-height:100vh;display:flex}.main-content{flex:1;width:100%;max-width:1280px;margin:0 auto;padding:1.5rem 1rem}.glass-card{background:var(--bg-card);-webkit-backdrop-filter:var(--glass-backdrop);border:1px solid var(--border-color);box-shadow:var(--shadow-glow);border-radius:20px;transition:all .3s cubic-bezier(.4,0,.2,1)}.glass-card:hover{border-color:#ffffff2e}.hanzi-text{font-family:var(--font-hanzi);letter-spacing:.04em;word-break:break-word;font-weight:700}.pinyin-text{font-family:var(--font-body);color:var(--accent-gold);font-weight:600}.viet-phonetic{color:var(--accent-cyan);background:#00e5ff1a;border-radius:6px;padding:3px 8px;font-size:.85em;font-weight:600;display:inline-block}.btn-primary{color:#070a12;cursor:pointer;box-shadow:0 4px 15px var(--primary-jade-glow);background:linear-gradient(135deg,#00e676 0%,#00b0ff 100%);border:none;border-radius:12px;justify-content:center;align-items:center;gap:.4rem;min-height:40px;padding:.65rem 1.25rem;font-weight:700;transition:all .2s;display:inline-flex}.btn-primary:active{transform:scale(.97)}.btn-secondary{color:var(--text-main);border:1px solid var(--border-color);cursor:pointer;background:#ffffff0f;border-radius:12px;align-items:center;gap:.4rem;min-height:40px;padding:.6rem 1rem;font-weight:600;transition:all .2s;display:inline-flex}.btn-secondary:active{background:#ffffff26}.btn-mic{color:#fff;cursor:pointer;background:linear-gradient(135deg,#ff3d00 0%,#ffc107 100%);border:none;border-radius:50%;justify-content:center;align-items:center;width:64px;height:64px;margin:0 auto;transition:all .3s;display:flex;box-shadow:0 0 25px #ff3d0080}.btn-mic.recording{background:linear-gradient(135deg,#ff1744 0%,#d50000 100%);animation:1.5s infinite pulseMic}@keyframes pulseMic{0%{transform:scale(1);box-shadow:0 0 #ff1744b3}50%{transform:scale(1.06);box-shadow:0 0 0 16px #ff174400}to{transform:scale(1);box-shadow:0 0 #ff174400}}.wave-container{justify-content:center;align-items:center;gap:3px;height:30px;display:flex}.wave-bar{background:var(--primary-jade);border-radius:4px;width:4px;animation:1.2s ease-in-out infinite alternate soundWave}.wave-bar:first-child{height:10px;animation-delay:.1s}.wave-bar:nth-child(2){height:20px;animation-delay:.3s}.wave-bar:nth-child(3){height:28px;animation-delay:.2s}.wave-bar:nth-child(4){height:18px;animation-delay:.4s}@keyframes soundWave{0%{transform:scaleY(.3)}to{transform:scaleY(1.3)}}.score-circle{border:5px solid var(--primary-jade);width:120px;height:120px;box-shadow:0 0 25px var(--primary-jade-glow);background:radial-gradient(circle,#0f172ae6 60%,#0000 100%);border-radius:50%;flex-direction:column;justify-content:center;align-items:center;margin:0 auto;display:flex;position:relative}.score-value{font-family:var(--font-heading);background:linear-gradient(135deg,#00e676,#00e5ff);-webkit-text-fill-color:transparent;-webkit-background-clip:text;font-size:2.4rem;font-weight:800;line-height:1}.score-label{text-transform:uppercase;letter-spacing:.1em;color:var(--text-muted);margin-top:2px;font-size:.7rem}.category-pill{border:1px solid var(--border-color);color:var(--accent-gold);background:#ffffff14;border-radius:16px;padding:4px 10px;font-size:.78rem;font-weight:600}.nav-tabs{border:1px solid var(--border-color);background:#0f172acc;border-radius:14px;gap:.4rem;padding:4px;display:flex}.tab-btn{color:var(--text-muted);cursor:pointer;background:0 0;border:none;border-radius:10px;align-items:center;gap:.4rem;padding:.5rem 1rem;font-size:.88rem;font-weight:600;transition:all .2s;display:flex}.tab-btn.active{background:var(--primary-jade);color:#070a12;box-shadow:0 4px 12px var(--primary-jade-glow)}.mobile-bottom-nav{-webkit-backdrop-filter:blur(16px);border-top:1px solid var(--border-color);z-index:999;background:#0b1329f2;justify-content:space-around;align-items:center;height:64px;padding:0 .5rem;display:none;position:fixed;bottom:0;left:0;right:0}.mobile-nav-item{color:var(--text-muted);cursor:pointer;background:0 0;border:none;border-radius:12px;flex-direction:column;justify-content:center;align-items:center;gap:2px;width:25%;padding:6px 12px;font-size:.72rem;font-weight:600;transition:all .2s;display:flex}.mobile-nav-item.active{color:var(--primary-jade)}.char-feedback-box{flex-wrap:wrap;justify-content:center;gap:5px;margin:.75rem 0;display:flex}.char-badge{font-family:var(--font-hanzi);border:2px solid #0000;border-radius:8px;justify-content:center;align-items:center;width:40px;height:40px;font-size:1.5rem;font-weight:700;display:flex}.char-badge.correct{color:#00e676;background:#00e67626;border-color:#00e676}.char-badge.missing{color:#ff3d00;opacity:.7;background:#ff3d0026;border-color:#ff3d00;text-decoration:line-through}.grid-days{grid-template-columns:repeat(auto-fill,minmax(280px,1fr));gap:1rem;display:grid}@media (width<=768px){.desktop-only{display:none!important}.mobile-bottom-nav{-webkit-backdrop-filter:blur(20px);border-top:1px solid var(--border-color);z-index:1000;height:64px;padding-bottom:env(safe-area-inset-bottom,0px);background:#070a12f2;justify-content:space-around;align-items:center;display:flex;position:fixed;bottom:0;left:0;right:0}.mobile-nav-item{color:var(--text-muted);cursor:pointer;background:0 0;border:none;flex-direction:column;flex:1;justify-content:center;align-items:center;gap:3px;padding:6px 8px;font-size:.68rem;font-weight:700;transition:all .2s;display:flex}.mobile-nav-item.active{color:#00e676}.mobile-nav-item.active svg{filter:drop-shadow(0 0 6px #00e67680)}.main-content{padding:.85rem .75rem 80px!important}.glass-card{border-radius:16px;padding:1.15rem!important}.grid-days{grid-template-columns:1fr}input,select,textarea{font-size:16px!important}button{min-height:40px}.mobile-bottom-nav{height:68px;padding-bottom:calc(env(safe-area-inset-bottom,0px) + 4px)}}.flashcard-3d-scene{perspective:1200px;-webkit-user-select:none;user-select:none;touch-action:manipulation;width:100%;max-width:580px;margin:0 auto}.flashcard-3d-card{width:100%;min-height:330px;transform-style:preserve-3d;-webkit-transform-style:preserve-3d;cursor:pointer;border-radius:28px;transition:transform .5s cubic-bezier(.34,1.56,.64,1);position:relative}.flashcard-3d-card.is-flipped{transform:rotateY(180deg)}.flashcard-face{backface-visibility:hidden;border:2px solid #ffffff1f;border-radius:28px;flex-direction:column;justify-content:space-between;align-items:center;width:100%;height:100%;padding:1.75rem 1.5rem;transition:border-color .3s,box-shadow .3s;display:flex;position:absolute;top:0;left:0;box-shadow:0 20px 45px #00000080,inset 0 1px 1px #ffffff26}.flashcard-face:hover{border-color:#00e5ff66;box-shadow:0 25px 50px #00e5ff26,inset 0 1px 1px #fff3}.flashcard-face.front{background:linear-gradient(145deg,#0f172af5 0%,#1e293bf5 100%);border-color:#00e5ff4d}.flashcard-face.back{background:linear-gradient(145deg,#0d241df5 0%,#0f172af5 100%);border-color:#00e67666;transform:rotateY(180deg)}.flashcard-badge{letter-spacing:.04em;border-radius:20px;align-items:center;gap:5px;padding:4px 12px;font-size:.78rem;font-weight:800;display:inline-flex}.flashcard-badge.cyan{color:#00e5ff;background:#00e5ff26;border:1px solid #00e5ff4d}.flashcard-badge.jade{color:#00e676;background:#00e67626;border:1px solid #00e6764d}.flashcard-hanzi{font-family:var(--font-hanzi);color:#fff;text-shadow:0 4px 15px #0006;text-align:center;margin:.4rem 0 .25rem;font-size:clamp(2.1rem,7.5vw,3rem);font-weight:900;line-height:1.25}.flashcard-pinyin{font-family:var(--font-body);color:#00e676;letter-spacing:.03em;text-align:center;background:#00e6761f;border:1px solid #00e6764d;border-radius:16px;margin-top:.25rem;padding:6px 20px;font-size:clamp(1.2rem,4.2vw,1.55rem);font-weight:800;box-shadow:0 4px 12px #00e67626}.flashcard-meaning{font-family:var(--font-heading);color:#fff;text-align:center;margin:.5rem 0;font-size:clamp(1.35rem,5vw,1.8rem);font-weight:800;line-height:1.4}.flashcard-ref-box{background:#00000040;border:1px solid #ffffff1a;border-radius:14px;align-items:center;gap:8px;padding:8px 16px;font-size:.9rem;display:flex}.flashcard-hint{color:var(--text-muted);background:#ffffff0d;border:1px solid #ffffff14;border-radius:20px;justify-content:center;align-items:center;gap:6px;padding:6px 14px;font-size:.8rem;display:flex}.sentences-mode-switcher{border:1px solid var(--border-color);background:#0f172ae6;border-radius:18px;align-items:center;gap:4px;width:100%;max-width:580px;padding:4px;display:flex}.sentences-mode-btn{min-width:0;color:var(--text-muted);cursor:pointer;white-space:nowrap;background:0 0;border:none;border-radius:12px;flex:1;justify-content:center;align-items:center;gap:6px;padding:8px 10px;font-size:.82rem;font-weight:700;transition:all .2s;display:flex}.sentences-mode-btn.active-list{color:#070a12;background:#00e676}.sentences-mode-btn.active-flashcard{color:#070a12;background:#00e5ff}.sentences-mode-btn.active-quiz{color:#070a12;background:#ffab00}.sentences-mode-btn.active-favorites{color:#fff;background:#ff3d00}@media (width<=540px){.sentences-mode-switcher{border-radius:16px;grid-template-columns:repeat(2,1fr);gap:6px;padding:6px;display:grid}.sentences-mode-btn{gap:4px;width:100%;padding:8px 4px;font-size:.76rem}.sentences-mode-btn svg{width:15px;height:15px}}