:root{--bg: #fbfaf6;--surface: #ffffff;--surface-2: #f4f1ea;--text: #1f2937;--text-dim: #6b7280;--primary: #ff8a3d;--primary-dark: #f06b14;--accent: #2bb673;--blue: #4ea7f0;--pink: #ff7aa6;--green: #6ec96b;--yellow: #f5c451;--border: #ece6da;--shadow: 0 6px 18px rgba(40, 30, 20, .06);--radius: 16px;--radius-sm: 10px;--font: -apple-system, "PingFang SC", "Microsoft YaHei", "Helvetica Neue", Helvetica, Arial, sans-serif}*{box-sizing:border-box}html,body,#root{height:100%}body{margin:0;font-family:var(--font);font-size:16px;color:var(--text);background:var(--bg);-webkit-font-smoothing:antialiased}a{color:var(--primary-dark);text-decoration:none}a:hover{text-decoration:underline}.loading{padding:40px;text-align:center;color:var(--text-dim)}.app{min-height:100%;display:flex;flex-direction:column}.topbar{display:flex;align-items:center;gap:24px;padding:14px 24px;background:var(--surface);border-bottom:1px solid var(--border);position:sticky;top:0;z-index:10}.brand{display:flex;align-items:center;gap:8px;font-weight:700;font-size:20px;color:var(--text)}.brand:hover{text-decoration:none}.brand-emoji{font-size:26px}.nav{display:flex;gap:8px}.nav a{padding:8px 14px;border-radius:999px;color:var(--text);font-weight:500}.nav a:hover{background:var(--surface-2);text-decoration:none}.nav a.active{background:var(--primary);color:#fff}.user-area{margin-left:auto;display:flex;gap:10px;align-items:center}.user-name{color:var(--text);font-weight:500}.btn{display:inline-flex;align-items:center;justify-content:center;padding:8px 16px;border-radius:999px;font-weight:600;font-size:15px;border:1px solid transparent;cursor:pointer;background:transparent;transition:transform .05s,background .15s;font-family:inherit}.btn:active{transform:translateY(1px)}.btn.primary{background:var(--primary);color:#fff}.btn.primary:hover{background:var(--primary-dark)}.btn.ghost{background:var(--surface-2);color:var(--text)}.btn.ghost:hover{background:var(--border);text-decoration:none}.btn.big{font-size:17px;padding:12px 24px}.btn[disabled]{opacity:.6;cursor:not-allowed}.main{flex:1;max-width:1200px;width:100%;margin:0 auto;padding:24px}.footer{padding:20px;text-align:center;color:var(--text-dim);font-size:13px;border-top:1px solid var(--border);background:var(--surface)}.home .hero{text-align:center;padding:24px 0 32px}.home .hero h1{font-size:36px;margin:0 0 8px}.home .lead{color:var(--text-dim);font-size:18px}.home .hint{color:var(--text-dim);margin-top:12px}.modes{display:grid;grid-template-columns:repeat(3,1fr);gap:20px}.mode-card{display:block;padding:32px 24px;border-radius:var(--radius);background:var(--surface);border:1px solid var(--border);text-align:center;color:var(--text);box-shadow:var(--shadow);transition:transform .15s,box-shadow .15s}.mode-card:hover{text-decoration:none;transform:translateY(-3px);box-shadow:0 12px 28px #281e141a}.mode-card h2{margin:12px 0 6px;font-size:22px}.mode-card p{margin:0;color:var(--text-dim)}.mode-emoji{font-size:48px}.mode-blue{border-top:6px solid var(--blue)}.mode-pink{border-top:6px solid var(--pink)}.mode-green{border-top:6px solid var(--green)}.toolbar{display:flex;flex-wrap:wrap;gap:12px;align-items:center;margin-bottom:20px}.search{flex:1;min-width:220px;padding:12px 16px;border-radius:999px;border:1px solid var(--border);background:var(--surface);font-size:16px;font-family:inherit}.search:focus{outline:none;border-color:var(--primary)}.region-tabs{display:flex;flex-wrap:wrap;gap:6px}.region-tab{padding:6px 14px;border-radius:999px;border:1px solid var(--border);background:var(--surface);cursor:pointer;font-family:inherit;font-size:14px}.region-tab:hover{background:var(--surface-2)}.region-tab.active{background:var(--primary);color:#fff;border-color:var(--primary)}.count{margin-left:auto;color:var(--text-dim);font-size:14px}.grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(180px,1fr));gap:16px}.card{background:var(--surface);border-radius:var(--radius-sm);padding:12px;text-align:center;border:1px solid var(--border);box-shadow:var(--shadow);transition:transform .1s}.card:hover{transform:translateY(-2px)}.card img{width:100%;aspect-ratio:3 / 2;object-fit:contain;border-radius:8px;background:#f0ece4;border:1px solid #e0d9c8;display:block;padding:4px;box-sizing:border-box}.card-name{margin-top:10px;font-weight:600}.card-sub{color:var(--text-dim);font-size:13px;margin-top:2px}.flashcards{max-width:680px;margin:0 auto}.flashcard{perspective:1200px;margin:24px 0;cursor:pointer}.flashcard-inner{position:relative;width:100%;aspect-ratio:3 / 2;transform-style:preserve-3d;transition:transform .5s}.flashcard.flipped .flashcard-inner{transform:rotateY(180deg)}.flashcard-face{position:absolute;top:0;right:0;bottom:0;left:0;backface-visibility:hidden;border-radius:var(--radius);background:var(--surface);border:1px solid var(--border);box-shadow:var(--shadow);display:flex;flex-direction:column;align-items:center;justify-content:center;padding:20px 20px 36px;overflow:hidden}.flashcard-front .flag-frame{position:relative;flex:1 1 auto;min-height:0;width:100%;display:flex;align-items:center;justify-content:center;background:#f0ece4;border:1px solid #e0d9c8;border-radius:10px;padding:8px;box-sizing:border-box}.flag-loading{position:absolute;top:0;right:0;bottom:0;left:0;display:flex;align-items:center;justify-content:center;pointer-events:none}.spinner{width:36px;height:36px;border:3px solid rgba(0,0,0,.1);border-top-color:var(--primary);border-radius:50%;animation:spin .8s linear infinite}@keyframes spin{to{transform:rotate(360deg)}}.flashcard-front img{transition:opacity .15s}.flashcard-front img{max-width:100%;max-height:100%;width:auto;height:auto;object-fit:contain;display:block}.flashcard-front .hint-small{margin-top:12px;font-size:13px;color:var(--text-dim);flex:none}.flashcard-back{transform:rotateY(180deg);background:var(--surface);text-align:center}.answer-name{font-size:36px;font-weight:700}.answer-en{color:var(--text-dim);margin-top:8px;font-size:18px}.answer-region{margin-top:16px;padding:4px 12px;background:var(--surface-2);border-radius:999px;font-size:14px;color:var(--text-dim)}.actions{display:flex;gap:12px;justify-content:center;margin:12px 0}.btn-icon{display:none}.kbd-hint{text-align:center;color:var(--text-dim);font-size:13px;margin-top:16px}.quiz{max-width:720px;margin:0 auto}.question{background:var(--surface);border-radius:var(--radius);border:1px solid var(--border);box-shadow:var(--shadow);padding:24px}.question-flag{position:relative;background:#f0ece4;border:1px solid #e0d9c8;border-radius:var(--radius-sm);padding:20px;display:flex;justify-content:center;align-items:center;min-height:220px}.question-flag img{max-width:100%;max-height:280px;object-fit:contain;border-radius:4px;transition:opacity .15s}.question-text{text-align:center;font-size:20px;font-weight:600;margin:20px 0 16px}.options{display:grid;grid-template-columns:repeat(2,1fr);gap:12px}.option{display:flex;align-items:center;gap:12px;padding:14px 18px;border-radius:var(--radius-sm);background:var(--surface);border:2px solid var(--border);font-size:17px;cursor:pointer;font-family:inherit;text-align:left;color:var(--text);transition:background .15s,border-color .15s}.option:hover:not(:disabled){border-color:var(--primary);background:#fff8f0}.option-num{width:28px;height:28px;border-radius:50%;background:var(--surface-2);display:inline-flex;align-items:center;justify-content:center;font-size:14px;font-weight:600;color:var(--text-dim);flex:none}.option.correct{background:#e8f7ec;border-color:var(--green)}.option.correct .option-num{background:var(--green);color:#fff}.option.wrong{background:#fde7e7;border-color:#e06b6b}.option.wrong .option-num{background:#e06b6b;color:#fff}.option.dimmed{opacity:.55}.quiz-done{max-width:480px;margin:40px auto;text-align:center;background:var(--surface);padding:40px 24px;border-radius:var(--radius);border:1px solid var(--border);box-shadow:var(--shadow)}.big-emoji{font-size:80px}.quiz-done h2{margin:8px 0}.auth-page{max-width:380px;margin:40px auto;background:var(--surface);padding:32px;border-radius:var(--radius);border:1px solid var(--border);box-shadow:var(--shadow)}.auth-page h1{margin:0 0 8px}.auth-page .hint{color:var(--text-dim);font-size:14px}.auth-form{display:flex;flex-direction:column;gap:16px;margin:20px 0}.auth-form label{display:flex;flex-direction:column;gap:6px;font-size:14px;color:var(--text-dim)}.auth-form input{padding:12px 14px;font-size:16px;border:1px solid var(--border);border-radius:var(--radius-sm);background:var(--bg);font-family:inherit}.auth-form input:focus{outline:none;border-color:var(--primary);background:#fff}.error{background:#fde7e7;color:#b13a3a;padding:10px 14px;border-radius:var(--radius-sm);font-size:14px}.profile h1{margin:0 0 24px}.profile section{margin-top:32px}.profile section h2{margin:0 0 12px}.stat-row{display:grid;grid-template-columns:repeat(4,1fr);gap:12px;margin-bottom:16px}.stat-card{background:var(--surface);padding:16px;border-radius:var(--radius-sm);border:1px solid var(--border);text-align:center}.stat-num{font-size:32px;font-weight:700}.stat-label{color:var(--text-dim);font-size:13px;margin-top:4px}.stat-desc{color:var(--text-dim);font-size:11px;margin-top:3px;opacity:.7}.stat-row-3{grid-template-columns:repeat(3,1fr)}.stat-green{background:#ebf8ee;border-color:#c6e6cd}.stat-blue{background:#eaf3fc;border-color:#c0d9f3}.stat-yellow{background:#fdf3d8;border-color:#ecd896}.stat-gray{background:var(--surface-2)}.quiz-history{list-style:none;padding:0;margin:0;background:var(--surface);border-radius:var(--radius-sm);border:1px solid var(--border)}.quiz-history li{display:flex;justify-content:space-between;padding:10px 14px;border-bottom:1px solid var(--border);font-size:14px}.quiz-history li:last-child{border-bottom:none}.quiz-history .dim{color:var(--text-dim)}.mini-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(120px,1fr));gap:12px}.mini-card{background:var(--surface);border:1px solid var(--border);border-radius:var(--radius-sm);padding:8px;text-align:center;font-size:13px}.mini-card img{width:100%;aspect-ratio:3 / 2;object-fit:contain;border-radius:6px;background:#f0ece4;border:1px solid #e0d9c8;padding:3px;box-sizing:border-box}.mini-card div{margin-top:6px}@media(max-width:720px){.topbar{flex-wrap:wrap;padding:12px 14px;gap:12px}.nav{order:3;width:100%;overflow-x:auto}.user-area{margin-left:auto}.main{padding:16px}.home .hero h1{font-size:28px}.modes,.options{grid-template-columns:1fr}.stat-row{grid-template-columns:repeat(2,1fr)}.answer-name{font-size:28px}.flashcards .actions{gap:8px}.flashcards .actions .btn{flex:1 1 0;min-width:0;padding:12px 6px;font-size:15px;white-space:nowrap}.flashcards .actions .btn-label{display:none}.flashcards .actions .btn-icon{display:inline;font-size:18px}}