:root{--bg: #f5f3ee;--surface: #ffffff;--primary: #5b8dee;--primary-dark: #3b6fd4;--accent: #f5a623;--success: #52c97a;--danger: #ff6b6b;--gold: #f5c842;--text: #1a1a2e;--text-soft: #6b7280;--border: #e5e7eb;--shadow: 0 6px 32px rgba(0,0,0,.1);--radius: 18px;--radius-sm: 12px;--font: "Segoe UI", "PingFang SC", system-ui, sans-serif;--fs: 18px}*,*:before,*:after{box-sizing:border-box;margin:0;padding:0}html{font-size:var(--fs)}body{font-family:var(--font);background:var(--bg);color:var(--text);min-height:100vh;-webkit-font-smoothing:antialiased;font-size:1rem}.app{max-width:760px;margin:0 auto;padding:28px 20px 64px}.btn{border:none;border-radius:var(--radius-sm);padding:13px 28px;font-size:1.1rem;font-weight:700;cursor:pointer;transition:all .18s;font-family:inherit}.btn-primary{background:var(--primary);color:#fff}.btn-primary:hover{background:var(--primary-dark);transform:translateY(-1px);box-shadow:0 4px 16px #5b8dee66}.btn-secondary{background:var(--surface);color:var(--text);border:2px solid var(--border)}.btn-secondary:hover{border-color:var(--primary);color:var(--primary)}.btn-gold{background:var(--gold);color:#7a4f00}.btn-sm{padding:7px 16px;font-size:.9rem;background:var(--primary);color:#fff;border:none;border-radius:8px;cursor:pointer}.btn-ghost{background:none;border:none;cursor:pointer;color:var(--text-soft)}.icon-btn{background:none;border:none;cursor:pointer;font-size:1.3rem;padding:6px;border-radius:8px}.btn-lg{display:flex;align-items:center;justify-content:center;gap:10px;background:var(--card-bg);border:2px solid var(--card-color);border-radius:16px;padding:18px 24px;font-size:1.05rem;font-weight:700;color:var(--card-color);cursor:pointer;transition:all .18s;box-shadow:none;width:100%}.btn-lg:hover{background:var(--card-bg)!important;opacity:.85;transform:translateY(-2px)}.icon-btn:hover{background:var(--border)}.app-header{text-align:center;padding:40px 0 28px}.app-header h1{font-size:1.6rem;font-weight:800;letter-spacing:-.5px;line-height:1.2}.app-subtitle{font-size:.9rem;color:var(--text-soft);margin-top:4px}.stats-bar{display:flex;justify-content:center;gap:12px;color:var(--text-soft);font-size:1.05rem;margin-top:14px}.mode-grid{display:grid;grid-template-columns:1fr 1fr;gap:18px;margin-bottom:36px}.mode-card{background:var(--surface);border:2px solid var(--border);border-radius:var(--radius);padding:28px 20px;text-align:center;cursor:pointer;transition:all .22s;display:flex;flex-direction:column;align-items:center;gap:10px}.mode-card:hover{border-color:var(--primary);transform:translateY(-3px);box-shadow:var(--shadow)}.mode-card.primary{background:linear-gradient(145deg,#5b8dee,#7aa3f5);color:#fff;border-color:transparent}.mode-card.primary:hover{box-shadow:0 10px 36px #5b8dee73}.mode-icon{font-size:3rem}.mode-title{font-size:1.4rem;font-weight:800}.mode-desc{font-size:1rem;opacity:.85;line-height:1.5}.level-tabs{display:flex;gap:10px;justify-content:center;margin-bottom:32px;padding:6px;background:var(--surface);border-radius:var(--radius);border:2px solid var(--border);box-shadow:0 2px 12px #0000000f}.level-tab{flex:1;padding:12px 20px;border:none;border-radius:12px;background:transparent;font-size:1.1rem;font-weight:700;color:var(--text-soft);cursor:pointer;transition:all .2s;display:flex;align-items:center;justify-content:center;gap:6px;position:relative}.level-tab.active{background:var(--primary);color:#fff;box-shadow:0 4px 16px #5b8dee66}.level-tab:not(.level-tab-locked):hover{background:#5b8dee1f}.level-tab-locked{opacity:.55;cursor:default}.level-lock{font-size:.85rem}.level-soon{font-size:.65rem;font-weight:700;background:var(--accent);color:#fff;border-radius:4px;padding:1px 5px;margin-left:2px}.section-title{font-size:1rem;font-weight:700;color:var(--text-soft);text-transform:uppercase;letter-spacing:1px;margin-bottom:14px}.unit-list{display:flex;flex-direction:column;gap:10px}.unit-row{background:var(--surface);border:2px solid var(--border);border-radius:var(--radius-sm);padding:18px 20px;display:flex;align-items:center;justify-content:space-between;transition:all .18s}.unit-row:hover{border-color:var(--primary);box-shadow:0 2px 12px #5b8dee26}.unit-row.completed{border-color:var(--success);background:#f0fdf4}.unit-info{display:flex;align-items:center;gap:12px}.unit-key{background:var(--primary);color:#fff;font-size:.78rem;font-weight:800;padding:3px 10px;border-radius:6px}.unit-title{font-size:1.05rem;font-weight:600}.unit-right{display:flex;align-items:center;gap:10px}.unit-count{font-size:.95rem;color:var(--text-soft)}.badge-complete{background:var(--success);color:#fff;font-size:.78rem;font-weight:700;padding:3px 10px;border-radius:6px}.browse-header{display:flex;align-items:center;gap:14px;margin-bottom:18px}.browse-header h2{font-size:1.8rem;font-weight:800}.course-tabs{display:flex;gap:8px;margin-bottom:14px}.course-tab{flex:1;border:2px solid var(--border);background:var(--surface);border-radius:8px;padding:10px 16px;font-size:1rem;font-weight:600;cursor:pointer;transition:all .15s}.course-tab:hover{border-color:var(--primary)}.course-tab.active{background:var(--primary);color:#fff;border-color:var(--primary)}.browse-stats{text-align:center;color:var(--text-muted);margin-bottom:12px;font-size:.9rem}.unit-tabs{display:flex;flex-wrap:wrap;gap:8px;margin-bottom:18px}.tab-btn{border:2px solid var(--border);background:var(--surface);border-radius:20px;padding:6px 16px;font-size:.95rem;cursor:pointer;transition:all .15s}.tab-btn:hover{border-color:var(--primary)}.tab-btn.active{background:var(--primary);color:#fff;border-color:var(--primary)}.browse-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(110px,1fr));gap:12px}.word-chip{background:var(--surface);border:2px solid var(--border);border-radius:var(--radius-sm);padding:12px 8px;text-align:center;cursor:pointer;transition:all .18s;display:flex;flex-direction:column;align-items:center;gap:6px}.word-chip:hover{border-color:var(--primary);transform:translateY(-2px);box-shadow:var(--shadow)}.word-chip-img{width:68px;height:68px;object-fit:contain}.word-chip-img[style*="opacity: 0.2"]{filter:grayscale(1)}.word-chip-name{font-size:.9rem;font-weight:700;word-break:break-all;line-height:1.3}.flashcard-scene{display:flex;flex-direction:column;align-items:center;gap:20px}.flashcard-meta{width:100%;display:flex;justify-content:space-between;font-size:1.05rem}.flashcard-unit{font-weight:700;color:var(--primary)}.flashcard-counter{color:var(--text-soft)}.flashcard{width:100%;max-width:480px}.flashcard-face{border-radius:22px;padding:28px;display:flex;flex-direction:column;align-items:center;justify-content:center;box-shadow:var(--shadow)}.flashcard-front{background:linear-gradient(160deg,#eef3ff,#fff)}.flashcard-img{width:140px;height:140px;object-fit:contain;margin-bottom:16px}.flashcard-word-row{display:flex;align-items:center;gap:14px}.flashcard-word{font-size:2.4rem;font-weight:900;letter-spacing:-.5px}.flashcard-hint{font-size:1rem;color:var(--text-soft);margin-top:12px}.flashcard-definition{font-size:1.3rem;line-height:1.7;text-align:center;margin-bottom:18px}.flashcard-phonetic{font-size:1.1rem;color:var(--primary);font-style:italic;margin-bottom:10px}.flashcard-controls{display:flex;gap:12px}.spelling-scene{display:flex;flex-direction:column;align-items:center;gap:20px}.spelling-header{width:100%;display:flex;align-items:center;gap:12px}.spelling-title{font-size:1.1rem;font-weight:700;flex:1}.spelling-score{font-size:1.2rem;font-weight:800;color:var(--accent)}.spelling-progress-bar{width:100%;height:6px;background:var(--border);border-radius:3px;overflow:hidden}.spelling-progress-fill{height:100%;background:linear-gradient(90deg,var(--primary),#7aa3f5);border-radius:3px;transition:width .5s ease}.phase-tag{text-align:center;font-size:1.3rem;font-weight:900;color:var(--primary)}.phase-correct{color:var(--success)}.phase-wrong{color:var(--danger);animation:shake .4s}.spell-card{width:100%;max-width:520px;background:var(--surface);border-radius:var(--radius);box-shadow:var(--shadow);display:flex;flex-direction:column;align-items:center;padding:28px 24px 24px;gap:14px}.spell-card-img{width:400px;height:600px;object-fit:contain}.spell-def{font-size:1.3rem;line-height:1.7;text-align:center;max-width:460px}.spell-phonetic{font-size:1.15rem;color:var(--primary);font-style:italic}.spell-audio-btn{background:#eef3ff;color:var(--primary);border:2px solid #d0dcff;font-size:1.1rem;padding:10px 26px}.spell-audio-btn:hover{background:#dce8ff}.spell-hint{font-size:1.1rem;color:var(--accent);font-weight:700;text-align:center}.spell-actions{display:flex;gap:12px}.btn-hint{background:#fff8ee;color:#b07d00;border:2px solid #f5d67a}.btn-hint:hover{background:#fff3d6}.btn-hint:disabled{opacity:.4;cursor:not-allowed}.btn-giveup{background:#f9fafb;color:var(--text-soft);border:2px solid var(--border)}.btn-giveup:hover{border-color:var(--danger);color:var(--danger)}.syllable-group-row{display:flex;gap:20px;justify-content:center;flex-wrap:wrap}.syllable-group{display:flex;flex-direction:column;align-items:center;gap:4px}.syllable-ipa{font-size:.9rem;color:#7a9cc6;font-style:italic;min-height:1.2em;letter-spacing:.5px}.syllable-boxes{display:flex;gap:6px;flex-wrap:wrap;justify-content:center}.letter-box{width:58px;height:68px;border-radius:12px;border:3px solid var(--border);text-align:center;font-size:2rem;font-weight:900;font-family:Courier New,monospace;background:var(--surface);transition:border-color .15s,background .15s,color .15s;outline:none}.letter-box:focus{border-color:var(--primary);background:#eef3ff}.letter-correct{border-color:var(--success)!important;background:#d1fae5!important;color:#15803d!important}.letter-wrong{border-color:var(--danger)!important;background:#fee2e2!important;color:#b91c1c!important;animation:shake .35s}.result-screen{display:flex;justify-content:center;align-items:center;min-height:60vh}.result-card{background:var(--surface);border-radius:var(--radius);padding:48px 36px;text-align:center;box-shadow:var(--shadow);max-width:400px;width:100%}.result-title{font-size:2rem;font-weight:900;margin-bottom:20px}.result-score{font-size:4rem;font-weight:900;color:var(--primary);line-height:1}.result-bar{height:12px;background:var(--border);border-radius:6px;overflow:hidden;margin:20px 0 10px}.result-bar-fill{height:100%;background:linear-gradient(90deg,var(--success),#22d3a0);border-radius:6px;transition:width 1s ease}.result-pct{font-size:1.1rem;color:var(--text-soft);margin-bottom:28px}@keyframes shake{0%,to{transform:translate(0)}20%,60%{transform:translate(-7px)}40%,80%{transform:translate(7px)}}.home-view{max-width:860px;margin:0 auto}.home-nav-tabs{display:flex;gap:8px;margin-bottom:28px;padding:5px;background:var(--surface);border-radius:var(--radius);border:2px solid var(--border);box-shadow:0 2px 12px #0000000f}.home-nav-tab{flex:1;padding:11px 18px;border:none;border-radius:12px;background:transparent;font-size:.95rem;font-weight:700;color:var(--text-soft);cursor:pointer;transition:all .2s;display:flex;align-items:center;justify-content:center;gap:6px}.home-nav-tab.active{background:var(--primary);color:#fff;box-shadow:0 4px 16px #5b8dee66}.home-nav-tab:not(.active):hover{background:#5b8dee1f;color:var(--primary)}.course-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(240px,1fr));gap:20px}.course-card{background:var(--surface);border-radius:20px;border:2px solid var(--border);padding:24px 20px;cursor:pointer;transition:transform .18s,box-shadow .18s;display:flex;flex-direction:column;gap:10px}.course-card:hover:not(.locked){transform:translateY(-4px);box-shadow:0 8px 24px #0000001a;border-color:var(--card-color)}.course-card.locked{opacity:.7;cursor:default}.course-card-header{display:flex;align-items:center;gap:10px}.course-icon{font-size:2.4rem}.course-id{font-size:.7rem;font-weight:800;letter-spacing:1px;padding:3px 10px;border-radius:20px;background:var(--card-bg);color:var(--card-color)}.course-lock{margin-left:auto;font-size:1.2rem}.course-title{font-size:1.5rem;font-weight:800;color:var(--text);line-height:1.2}.course-subtitle{font-size:.9rem;color:var(--text-soft)}.course-units-preview{display:flex;flex-wrap:wrap;gap:6px;margin-top:4px}.unit-chip{font-size:.72rem;font-weight:700;padding:3px 9px;border-radius:6px;background:var(--card-bg);color:var(--card-color)}.unit-chip.muted{background:var(--surface);color:var(--text-soft);border:1px solid var(--border)}.course-btn{margin-top:8px;padding:10px 18px;border-radius:10px;background:var(--card-color);color:#fff;font-size:.9rem;font-weight:700;text-align:center;display:block}.course-btn.locked{background:var(--text-soft);cursor:default}.level-view{max-width:860px;margin:0 auto;padding:24px 28px}.back-btn{background:none;border:none;color:var(--primary);font-size:.95rem;font-weight:600;cursor:pointer;padding:0;margin-bottom:20px;display:flex;align-items:center;gap:4px}.back-btn:hover{text-decoration:underline}.level-banner{display:flex;align-items:center;gap:20px;background:var(--card-bg);border-radius:16px;padding:20px 22px;border:2px solid var(--card-color);margin-bottom:20px}.random-btn-wrap{margin-bottom:20px}.level-icon{font-size:3.5rem}.level-title{font-size:1.8rem;font-weight:800;color:var(--card-color)}.level-subtitle{font-size:.9rem;color:var(--text-soft);margin-top:4px}.unit-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(200px,1fr));gap:16px}.unit-card{background:var(--surface);border-radius:16px;border:2px solid var(--border);padding:20px 18px;display:flex;flex-direction:column;gap:8px;min-width:0;min-height:0;overflow:hidden;transition:transform .18s,box-shadow .18s}.unit-card:hover{transform:translateY(-3px);box-shadow:0 6px 20px #00000014}.unit-card.done{border-color:var(--success)}.unit-key-row{margin-bottom:4px;min-width:0;flex-shrink:0}.unit-card-key{font-size:.68rem;font-weight:800;letter-spacing:1px;padding:2px 7px;border-radius:6px;font-size:.65rem;background:var(--card-color);color:#fff}.unit-card.done .unit-card-key{background:var(--success)}.unit-title-row{display:flex;align-items:center;justify-content:space-between;gap:8px;margin-bottom:0;padding:5px 6px;border-radius:8px;background:linear-gradient(135deg,#f8fafc,#f1f5f9);min-width:0}.unit-stars{font-size:1rem;color:#f59e0b;flex-shrink:0}.unit-card-title{font-size:1rem;font-weight:700;color:var(--text);line-height:1.3;margin:0}.unit-card-meta{font-size:.78rem;color:var(--text-soft);margin:3px 0 4px 6px}.unit-card-actions{display:flex;gap:8px;margin-top:6px}.unit-card-actions .btn{flex:1}.unit-action-btn{display:flex;flex-direction:column;align-items:center;gap:4px;flex:1;padding:10px 8px 8px;border-radius:14px;cursor:pointer;border:1.5px solid;font-size:.78rem;font-weight:700;transition:all .18s;line-height:1.2;min-width:0}.unit-action-btn:hover{transform:translateY(-2px);box-shadow:0 4px 14px #0000001f}.unit-action-btn:active{transform:translateY(0)}.unit-action-icon{font-size:1.5rem;line-height:1}.unit-action-label{font-size:.75rem;font-weight:700}.unit-action-btn.challenge{background:linear-gradient(135deg,#dbeafe,#eff6ff);border-color:#93c5fd;color:#1d4ed8}.unit-action-btn.challenge:hover{background:linear-gradient(135deg,#bfdbfe,#dbeafe);border-color:#60a5fa;box-shadow:0 4px 16px #3b82f633}.unit-action-btn.learn{background:linear-gradient(135deg,#ede9fe,#f5f3ff);border-color:#c4b5fd;color:#6d28d9}.unit-action-btn.learn:hover{background:linear-gradient(135deg,#ddd6fe,#ede9fe);border-color:#a78bfa;box-shadow:0 4px 16px #8b5cf633}.embedded-view{margin-top:24px;background:var(--surface);border-radius:20px;border:1px solid #e5e7eb;box-shadow:0 2px 16px #0000000f;padding:24px;position:relative}.embedded-header{margin-bottom:16px;border-bottom:1px solid #e5e7eb;padding-bottom:12px}.browse-all-view{max-width:860px;margin:0 auto}.flashcard-standalone .flashcard-container{max-width:500px;margin:0 auto}@media (max-width: 520px){.app{padding:18px 14px 48px}.app-header h1{font-size:2rem}.mode-grid{grid-template-columns:1fr}.app-header-row{display:flex;align-items:flex-start;justify-content:space-between;gap:16px;margin-bottom:28px}.stats-card-btn{display:flex;align-items:center;gap:14px;background:linear-gradient(135deg,#bfdbfe,#dbeafe);border:1.5px solid #93c5fd;border-radius:20px;padding:12px 18px;cursor:pointer;transition:all .18s;flex-shrink:0;min-width:190px}.stats-card-btn:hover{background:linear-gradient(135deg,#93c5fd,#bfdbfe);border-color:#60a5fa;transform:translateY(-2px);box-shadow:0 6px 20px #3b82f633}.stats-card-btn .stats-card-label{color:#1d4ed8;font-size:1rem;font-weight:700;line-height:1}.stats-card-btn .stats-card-arrow{color:#60a5fa;margin-left:auto;flex-shrink:0;transition:transform .18s,color .18s}.stats-card-btn:hover .stats-card-arrow{transform:translate(4px);color:#2563eb}.stats-card-btn .stats-card-icon{color:#3b82f6}.stats-card-icon{width:28px;height:28px;flex-shrink:0;color:var(--primary)}.stats-card-label{font-size:1rem;font-weight:800;color:var(--text);line-height:1}.stats-card-arrow{font-size:1.2rem;color:var(--text-soft);margin-left:auto;flex-shrink:0;transition:transform .18s,color .18s}.stats-card-btn:hover .stats-card-arrow{transform:translate(4px);color:var(--primary)}.stats-page{max-width:480px;margin:0 auto;padding:16px 16px 40px;min-height:100vh}.stats-header{display:flex;align-items:center;gap:12px;margin-bottom:24px;padding-top:4px}.stats-title{font-size:1.4rem;font-weight:700;color:var(--text)}.stats-empty{text-align:center;padding:60px 20px;color:var(--text-soft)}.stats-empty-icon{font-size:4rem;margin-bottom:16px}.stats-empty h2{font-size:1.3rem;margin-bottom:8px;color:var(--text)}.stats-empty p{margin-bottom:24px}.stats-overview{display:grid;grid-template-columns:auto 1fr 1fr 1fr;gap:12px;margin-bottom:28px;align-items:center}.stat-card{background:var(--surface);border-radius:var(--radius-sm);padding:14px 10px;text-align:center;box-shadow:0 2px 12px #0000000f}.stat-number{font-size:1.7rem;font-weight:800;color:var(--primary);line-height:1}.stat-max{font-size:.8rem;color:var(--text-soft);font-weight:400}.stat-label{font-size:.68rem;color:var(--text-soft);margin-top:4px;line-height:1.3}.donut-wrap{display:flex;flex-direction:column;align-items:center;gap:4px}.donut-label{font-size:.65rem;color:var(--text-soft)}.stats-section{background:var(--surface);border-radius:var(--radius-sm);padding:18px;margin-bottom:16px;box-shadow:0 2px 12px #0000000f}.stats-section-title{font-size:.85rem;font-weight:700;color:var(--text);margin-bottom:14px;letter-spacing:.02em;text-transform:uppercase}.bar-chart{display:block;overflow:visible}.bar-rect{transition:opacity .2s}.bar-rect:hover{opacity:.8}.chart-empty{text-align:center;padding:20px;color:var(--text-soft);font-size:.85rem}.trend-grid{display:flex;gap:6px;justify-content:space-between}.trend-day{flex:1;text-align:center;padding:8px 2px;border-radius:8px;background:#f8fafc}.trend-day.empty{background:transparent}.trend-day-label{font-size:.65rem;color:var(--text-soft);margin-bottom:4px}.trend-day-value{font-size:.75rem;font-weight:700}.unit-progress-list{display:flex;flex-direction:column;gap:10px}.unit-progress-row{display:flex;align-items:center;gap:10px}.up-left{display:flex;align-items:center;gap:8px;min-width:80px}.up-key{font-weight:800;font-size:.8rem;color:var(--primary)}.up-title{font-size:.75rem;color:var(--text-soft);white-space:nowrap;overflow:hidden;text-overflow:ellipsis;max-width:100px}.up-mid{flex:1}.up-right{display:flex;flex-direction:column;align-items:flex-end;gap:2px;min-width:52px}.up-score{font-size:.7rem;color:var(--text-soft)}.prog-bar-wrap{background:#f1f5f9;border-radius:99px;overflow:hidden;width:100%}.prog-bar-fill{height:100%;border-radius:99px;transition:width .5s ease}.unit-stars-row{display:flex;gap:1px}.star{color:#e2e8f0;font-size:.8rem}.star.lit{color:var(--gold)}.stats-two-col{display:grid;grid-template-columns:1fr 1fr;gap:16px}.stats-col .stats-section-title{font-size:.75rem}.word-list{display:flex;flex-direction:column;gap:6px}.word-accuracy-row{display:flex;align-items:center;gap:6px}.war-word{font-size:.75rem;font-weight:600;min-width:72px;color:var(--text)}.war-bar-wrap{flex:1;height:6px;background:#f1f5f9;border-radius:99px;overflow:hidden}.war-bar{height:100%;border-radius:99px;transition:width .5s ease}.war-pct{font-size:.65rem;color:var(--text-soft);min-width:28px;text-align:right}.stats-empty-hint{font-size:.8rem;color:var(--text-soft);text-align:center;padding:12px 0}.session-list{display:flex;flex-direction:column;gap:8px}.session-row{display:flex;align-items:center;gap:10px;font-size:.78rem}.session-date{color:var(--text-soft);min-width:70px}.session-unit{font-weight:700;color:var(--primary);min-width:30px}.session-score{font-weight:800;min-width:36px}.session-bar-wrap{flex:1;height:5px;background:#f1f5f9;border-radius:99px;overflow:hidden}.session-bar{height:100%;border-radius:99px}.stats-footer{display:flex;align-items:center;justify-content:space-between;padding:14px 18px}.stats-footer p{font-size:.72rem;color:var(--text-soft)}}