:root{--color-primary: #4F6DFF;--color-primary-light: #7B8FFF;--color-primary-dark: #2E4BD9;--color-accent-pink: #FF6B9D;--color-accent-orange: #FF9F43;--color-accent-green: #2ED573;--color-accent-teal: #1DD1A1;--color-accent-yellow: #FECA57;--color-accent-purple: #A55EEA;--color-bg: #F8FAFF;--color-bg-card: #FFFFFF;--color-bg-daily: linear-gradient(135deg, #4F6DFF 0%, #A55EEA 100%);--color-bg-correct: #E8F8F0;--color-bg-wrong: #FDEDEC;--color-text: #2C3E50;--color-text-light: #7F8C8D;--color-text-inverse: #FFFFFF;--color-border: #E8ECF4;--shadow-sm: 0 2px 8px rgba(0, 0, 0, .06);--shadow-md: 0 4px 16px rgba(0, 0, 0, .08);--shadow-lg: 0 8px 32px rgba(0, 0, 0, .12);--radius-sm: 8px;--radius-md: 16px;--radius-lg: 24px;--radius-xl: 32px;--space-xs: 4px;--space-sm: 8px;--space-md: 16px;--space-lg: 24px;--space-xl: 32px;--transition-fast: .15s ease;--transition-normal: .25s ease;--transition-slow: .4s ease;--bottom-nav-height: 64px}[data-theme=dark]{--color-bg: #1A1B2E;--color-bg-card: #252640;--color-text: #E4E5F1;--color-text-light: #8E8FAD;--color-border: #3A3B5A;--shadow-sm: 0 2px 8px rgba(0, 0, 0, .2);--shadow-md: 0 4px 16px rgba(0, 0, 0, .3);--shadow-lg: 0 8px 32px rgba(0, 0, 0, .4)}*,*:before,*:after{margin:0;padding:0;box-sizing:border-box}html{font-size:16px;-webkit-font-smoothing:antialiased;-moz-osx-font-smoothing:grayscale}body{font-family:-apple-system,BlinkMacSystemFont,Segoe UI,PingFang TC,Microsoft JhengHei,sans-serif;background:var(--color-bg);color:var(--color-text);min-height:100vh;overflow-x:hidden}#app{max-width:430px;margin:0 auto;min-height:100vh;position:relative;padding-bottom:var(--bottom-nav-height)}@media(min-width:768px){body{display:flex;justify-content:center;align-items:flex-start;padding:24px;background:linear-gradient(135deg,#e8ecf4,#d4d9e8)}#app{max-width:430px;width:100%;min-height:calc(100vh - 48px);background:var(--color-bg);border-radius:var(--radius-lg);box-shadow:var(--shadow-lg);overflow:hidden}[data-theme=dark] 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var(--transition-fast);min-height:48px;touch-action:manipulation}.btn:active{transform:scale(.97)}.btn-primary{background:var(--color-primary);color:#fff}.btn-primary:hover{background:var(--color-primary-dark)}.btn-success{background:var(--color-accent-green);color:#fff}.btn-danger{background:var(--color-accent-pink);color:#fff}.btn-outline{background:transparent;border:2px solid var(--color-border);color:var(--color-text)}.btn-outline:hover{border-color:var(--color-primary);color:var(--color-primary)}.btn-ghost{background:transparent;color:var(--color-text-light)}.choice-btn{width:100%;padding:var(--space-md);border:2px solid var(--color-border);border-radius:var(--radius-sm);background:var(--color-bg-card);color:var(--color-text);font-size:1rem;cursor:pointer;transition:all var(--transition-fast);text-align:left;min-height:56px;display:flex;align-items:center}.choice-btn:hover{border-color:var(--color-primary-light)}.choice-btn.selected{border-color:var(--color-primary);background:#4f6dff14}.choice-btn.correct{border-color:var(--color-accent-green);background:var(--color-bg-correct)}.choice-btn.wrong{border-color:#e74c3c;background:var(--color-bg-wrong)}.match-card{padding:var(--space-md);border:2px solid var(--color-border);border-radius:var(--radius-sm);background:var(--color-bg-card);cursor:pointer;transition:all var(--transition-fast);text-align:center;font-weight:600;min-height:60px;display:flex;align-items:center;justify-content:center;user-select:none}.match-card:hover{border-color:var(--color-primary-light);transform:translateY(-2px)}.match-card.selected{border-color:var(--color-primary);background:#4f6dff14;box-shadow:0 0 0 3px #4f6dff26}.match-card.matched{border-color:var(--color-accent-green);background:var(--color-bg-correct);opacity:.6;pointer-events:none}.flashcard{perspective:1000px;width:100%;aspect-ratio:4/3}.flashcard-inner{position:relative;width:100%;height:100%;transition:transform .6s;transform-style:preserve-3d;cursor:pointer}.flashcard.flipped .flashcard-inner{transform:rotateY(180deg)}.flashcard-front,.flashcard-back{position:absolute;width:100%;height:100%;backface-visibility:hidden;border-radius:var(--radius-md);display:flex;flex-direction:column;align-items:center;justify-content:center;padding:var(--space-lg);box-shadow:var(--shadow-md)}.flashcard-front{background:var(--color-bg-card);border:2px solid var(--color-border)}.flashcard-back{background:linear-gradient(135deg,var(--color-primary) 0%,var(--color-accent-purple) 100%);color:#fff;transform:rotateY(180deg)}.progress-bar{width:100%;height:8px;background:var(--color-border);border-radius:4px;overflow:hidden}.progress-bar-fill{height:100%;background:linear-gradient(90deg,var(--color-primary),var(--color-accent-teal));border-radius:4px;transition:width var(--transition-slow)}.bottom-nav{position:fixed;bottom:0;left:50%;transform:translate(-50%);width:100%;max-width:430px;height:var(--bottom-nav-height);background:var(--color-bg-card);border-top:1px solid var(--color-border);display:flex;justify-content:space-around;align-items:center;padding:0 var(--space-sm);z-index:100;box-shadow:0 -2px 12px #0000000f}.bottom-nav-item{display:flex;flex-direction:column;align-items:center;gap:2px;padding:var(--space-xs) var(--space-sm);border:none;background:none;color:var(--color-text-light);font-size:.7rem;cursor:pointer;transition:color var(--transition-fast);flex:1}.bottom-nav-item.active{color:var(--color-primary)}.bottom-nav-item svg{width:24px;height:24px}@media(min-width:768px){.bottom-nav{border-bottom-left-radius:var(--radius-lg);border-bottom-right-radius:var(--radius-lg)}}@keyframes fadeIn{0%{opacity:0;transform:translateY(8px)}to{opacity:1;transform:translateY(0)}}@keyframes popIn{0%{transform:scale(.8);opacity:0}70%{transform:scale(1.05)}to{transform:scale(1);opacity:1}}@keyframes shake{0%,to{transform:translate(0)}20%{transform:translate(-8px)}40%{transform:translate(8px)}60%{transform:translate(-4px)}80%{transform:translate(4px)}}@keyframes celebrate{0%{transform:scale(0) rotate(0)}50%{transform:scale(1.2) rotate(180deg)}to{transform:scale(1) rotate(360deg)}}@keyframes float{0%,to{transform:translateY(0)}50%{transform:translateY(-8px)}}@keyframes confetti{0%{transform:translateY(-10px) rotate(0);opacity:1}to{transform:translateY(100vh) rotate(720deg);opacity:0}}.animate-fade-in{animation:fadeIn .4s ease forwards}.animate-pop-in{animation:popIn .3s ease forwards}.animate-shake{animation:shake .5s ease}.animate-float{animation:float 3s ease-in-out infinite}.streak-badge{display:inline-flex;align-items:center;gap:var(--space-xs);background:linear-gradient(135deg,#ff9f43,#ff6b6b);color:#fff;padding:var(--space-xs) var(--space-sm);border-radius:20px;font-size:.85rem;font-weight:700}.xp-badge{display:inline-flex;align-items:center;gap:var(--space-xs);background:linear-gradient(135deg,var(--color-primary),var(--color-accent-purple));color:#fff;padding:var(--space-xs) var(--space-sm);border-radius:20px;font-size:.85rem;font-weight:700}.level-badge{display:inline-flex;align-items:center;gap:var(--space-xs);background:linear-gradient(135deg,var(--color-accent-teal),var(--color-accent-green));color:#fff;padding:var(--space-xs) var(--space-md);border-radius:20px;font-size:.9rem;font-weight:700}.confetti-piece{position:fixed;width:10px;height:10px;top:-10px;z-index:9999;animation:confetti 3s ease-out forwards}::-webkit-scrollbar{width:4px}::-webkit-scrollbar-track{background:transparent}::-webkit-scrollbar-thumb{background:var(--color-border);border-radius:2px}.text-center{text-align:center}.text-primary{color:var(--color-primary)}.text-success{color:var(--color-accent-green)}.text-danger{color:#e74c3c}.mt-sm{margin-top:var(--space-sm)}.mt-md{margin-top:var(--space-md)}.mt-lg{margin-top:var(--space-lg)}.mb-sm{margin-bottom:var(--space-sm)}.mb-md{margin-bottom:var(--space-md)}.mb-lg{margin-bottom:var(--space-lg)}.flex{display:flex}.flex-col{flex-direction:column}.items-center{align-items:center}.justify-center{justify-content:center}.gap-sm{gap:var(--space-sm)}.gap-md{gap:var(--space-md)}.w-full{width:100%}.hidden{display:none!important}.theme-toggle-label[data-astro-cid-j7pv25f6] .slider[data-astro-cid-j7pv25f6]{position:absolute;cursor:pointer;inset:0;background-color:var(--color-border);border-radius:26px;transition:.3s}.theme-toggle-label[data-astro-cid-j7pv25f6] .slider[data-astro-cid-j7pv25f6]:before{position:absolute;content:"";height:20px;width:20px;left:3px;bottom:3px;background-color:#fff;border-radius:50%;transition:.3s;box-shadow:0 2px 4px #0003}.theme-toggle-label[data-astro-cid-j7pv25f6] input[data-astro-cid-j7pv25f6]:checked+.slider[data-astro-cid-j7pv25f6]{background:linear-gradient(135deg,var(--color-primary),var(--color-accent-purple))}.theme-toggle-label[data-astro-cid-j7pv25f6] input[data-astro-cid-j7pv25f6]:checked+.slider[data-astro-cid-j7pv25f6]:before{transform:translate(22px)}