@import"https://fonts.googleapis.com/css2?family=Bricolage+Grotesque:opsz,wght@12..96,600..800&family=Inter:wght@400;500;600;700&display=swap";:root{--paper: #F3F0E8;--card: #FDFCF9;--ink: #22221E;--ink-soft: #6B6A62;--line: #E4DFD3;--pine: #2F6A4F;--pine-deep: #245640;--pine-soft: #E5EFE8;--amber: #BB7830;--amber-soft: #F5E8D6;--danger: #C0503A;--white: #FFFFFF;--display: "Bricolage Grotesque", "PingFang HK", "Noto Sans HK", sans-serif;--body: "Inter", "PingFang HK", "Noto Sans HK", "Microsoft JhengHei", sans-serif}*{margin:0;padding:0;box-sizing:border-box}body{font-family:var(--body);background:var(--paper);color:var(--ink);min-height:100vh;padding-bottom:84px}#root{max-width:480px;margin:0 auto;min-height:100vh;background:var(--paper);position:relative}.header{background:var(--paper);padding:18px 20px 12px;text-align:center;position:sticky;top:0;z-index:100}.header h1{font-family:var(--display);font-weight:800;letter-spacing:.05em;font-size:20px;color:var(--ink)}.header .subtitle{font-size:12px;color:var(--ink-soft);margin-top:4px;letter-spacing:.08em}.nav{display:flex;position:fixed;bottom:0;left:50%;transform:translate(-50%);width:100%;max-width:480px;background:var(--card);border-top:1px solid var(--line);z-index:100}.nav-btn{flex:1;padding:10px 6px 12px;text-align:center;border:none;background:none;color:var(--ink-soft);font-size:11px;font-weight:600;cursor:pointer;text-decoration:none;display:flex;flex-direction:column;align-items:center;gap:3px}.nav-btn.active{color:var(--pine)}.nav-btn .icon{font-size:20px}.page{padding:8px 20px 20px;max-width:480px;margin:0 auto}.card{background:var(--card);border:1px solid var(--line);border-radius:18px;padding:22px;margin-bottom:16px;box-shadow:0 4px 14px #2f6a4f0d}.flashcard-container{perspective:1200px;margin:20px 0}.flashcard{width:100%;min-height:200px;position:relative;transform-style:preserve-3d;transition:transform .5s;cursor:pointer}.flashcard.flipped{transform:rotateY(180deg)}.flashcard-front,.flashcard-back{position:absolute;width:100%;min-height:200px;backface-visibility:hidden;border-radius:18px;display:flex;flex-direction:column;align-items:center;justify-content:center;padding:24px}.flashcard-front{background:var(--card);border:2px solid var(--pine)}.flashcard-back{background:var(--pine-soft);border:2px solid var(--pine);transform:rotateY(180deg)}.flashcard-word{font-family:var(--display);font-size:28px;font-weight:800;margin-bottom:12px;color:var(--ink)}.flashcard-example{font-size:14px;color:var(--ink-soft);font-style:italic}.flashcard-category{font-size:11px;background:var(--pine-soft);padding:4px 10px;border-radius:12px;margin-top:12px;color:var(--pine)}.flashcard-hint{font-size:12px;color:var(--ink-soft);margin-top:8px}.btn{padding:13px 24px;border:none;border-radius:12px;font-family:var(--display);font-size:15px;font-weight:700;cursor:pointer;transition:transform .1s}.btn:active{transform:scale(.96)}.btn-correct{background:var(--pine);color:#fff}.btn-wrong{background:var(--amber);color:#fff}.btn-primary{background:var(--pine);color:#fff}.btn-secondary{background:var(--card);color:var(--ink);border:1px solid var(--line)}.btn-small{padding:8px 16px;font-size:13px}.review-buttons{display:flex;gap:12px;justify-content:center;margin-top:20px}.review-buttons .btn{flex:1;max-width:150px}.form-group{margin-bottom:16px}.form-group label{display:block;font-size:13px;color:var(--ink-soft);margin-bottom:6px}.form-group input,.form-group select{width:100%;padding:12px 16px;border:1px solid var(--line);border-radius:10px;background:var(--white);color:var(--ink);font-size:16px;font-family:var(--body)}.form-group input:focus,.form-group select:focus{outline:none;border-color:var(--pine)}.grammar-input{width:100%;padding:12px;border:2px solid var(--pine);border-radius:10px;background:var(--white);color:var(--ink);font-size:18px;text-align:center;margin:16px 0}.stat-grid{display:grid;grid-template-columns:1fr 1fr;gap:12px;margin:16px 0}.stat-box{background:var(--card);border:1px solid var(--line);border-radius:14px;padding:16px;text-align:center}.stat-number{font-family:var(--display);font-size:32px;font-weight:800;color:var(--pine)}.stat-label{font-size:12px;color:var(--ink-soft);margin-top:4px}.word-item{display:flex;justify-content:space-between;align-items:center;padding:12px 16px;background:var(--card);border:1px solid var(--line);border-radius:12px;margin-bottom:8px;cursor:pointer}.word-item .word-text{font-size:15px;color:var(--ink)}.word-item .word-trans{font-size:13px;color:var(--ink-soft)}.word-item .word-score{font-size:11px;padding:4px 8px;border-radius:8px;background:var(--pine-soft);color:var(--pine)}.section-title{font-family:var(--display);font-size:16px;font-weight:700;margin:20px 0 12px;color:var(--ink)}.word-chip{display:inline-block;padding:8px 14px;margin:4px;border-radius:20px;background:var(--card);border:1px solid var(--line);font-size:14px;color:var(--ink);cursor:pointer;-webkit-user-select:none;user-select:none}.word-chip.selected{background:var(--pine-soft);border-color:var(--pine);color:var(--pine)}.word-chip .chip-trans{font-size:11px;color:var(--ink-soft);display:block;margin-top:2px}.explanation-box{background:var(--pine-soft);border-left:4px solid var(--pine);padding:12px 16px;border-radius:0 12px 12px 0;margin-top:12px;font-size:13px;color:var(--pine-deep)}.table-wrap{overflow-x:auto;margin:12px 0;-webkit-overflow-scrolling:touch}.grammar-table{min-width:100%;border-collapse:collapse;font-size:12px;white-space:nowrap}.grammar-table th{background:var(--pine-soft);color:var(--pine-deep);padding:6px 8px;text-align:left;border:1px solid var(--line)}.grammar-table td{padding:6px 8px;border:1px solid var(--line);color:var(--ink)}.grammar-table tr:nth-child(2n) td{background:#faf7f0}.chat-box{margin-top:16px;border-top:1px solid var(--line);padding-top:16px}.chat-msg{padding:10px 14px;border-radius:12px;margin-bottom:8px;font-size:14px;line-height:1.6}.chat-msg.user{background:var(--pine-soft);color:var(--pine-deep);margin-left:40px}.chat-msg.ai{background:var(--card);border:1px solid var(--line);color:var(--ink);margin-right:20px}.chat-input-row{display:flex;gap:8px;margin-top:12px}.chat-input-row input{flex:1;padding:10px 14px;border:1px solid var(--line);border-radius:10px;background:var(--white);color:var(--ink);font-size:14px}.progress-bar{height:8px;background:var(--line);border-radius:4px;margin:12px 0;overflow:hidden}.progress-fill{height:100%;border-radius:4px;transition:width .5s ease}.progress-fill.green{background:var(--pine)}.progress-fill.blue{background:var(--amber)}.toast{position:fixed;top:80px;left:50%;transform:translate(-50%);background:var(--ink);color:var(--paper);padding:12px 24px;border-radius:12px;z-index:1000;font-size:14px;opacity:0;transition:opacity .3s;pointer-events:none}.toast.show{opacity:1}.loading{text-align:center;padding:40px;color:var(--ink-soft)}.spinner{width:30px;height:30px;border:3px solid var(--line);border-top-color:var(--pine);border-radius:50%;animation:spin .8s linear infinite;margin:0 auto 12px}.empty-state{text-align:center;padding:40px 20px;color:var(--ink-soft)}.empty-state .icon{font-size:48px;margin-bottom:12px}.counter{text-align:center;color:var(--ink-soft);font-size:13px;margin-bottom:12px}.article-badge{display:inline-block;background:var(--pine);color:#fff;padding:2px 8px;border-radius:6px;font-size:12px;font-weight:700;margin-left:8px}@keyframes spin{to{transform:rotate(360deg)}}