@import"https://fonts.googleapis.com/css2?family=Noto+Sans+TC:wght@400;500;700;900&display=swap";*,*:before,*:after{box-sizing:border-box;margin:0;padding:0}html{font-size:16px;scroll-behavior:smooth}:root{--font: "Noto Sans TC", "PingFang TC", "Microsoft JhengHei", sans-serif;--primary: #0B5EAC;--primary-dark: #094d91;--primary-light: #E8F0FE;--primary-hover: #72A0CB;--success: #16A34A;--success-light: #DCFCE7;--danger: #DC2626;--danger-light: #FEE2E2;--warning: #D97706;--warning-light: #FEF3C7;--bg: #F6F7F9;--card-bg: #fff;--card-border: #EEEFF2;--text-primary: #191919;--text-secondary: #6B6B6B;--gray-50: #F6F7F9;--gray-100: #EEEFF2;--gray-200: #D9D9D9;--gray-300: #C4C4C4;--gray-400: #9CA3AF;--gray-500: #6B6B6B;--gray-600: #4B5563;--gray-700: #374151;--radius: 16px;--radius-sm: 8px;--radius-pill: 20px;--shadow: 0 1px 3px rgba(0,0,0,.08), 0 1px 2px rgba(0,0,0,.06);--shadow-md: 0 4px 6px rgba(0,0,0,.07), 0 2px 4px rgba(0,0,0,.06);--shadow-lg: 0 0 40px rgba(25,25,25,.2)}body{font-family:var(--font);background:var(--bg);color:var(--text-primary);line-height:1.6;-webkit-font-smoothing:antialiased;min-height:100vh;padding-top:64px;transition:background .3s,color .3s}.navbar{position:fixed;top:0;left:0;right:0;z-index:100;background:var(--primary);height:64px}.navbar-inner{max-width:1400px;margin:0 auto;display:flex;align-items:center;padding:8px 60px;height:100%;gap:8px}@media (max-width: 768px){.navbar-inner{padding:8px 16px}}.navbar-brand{display:flex;align-items:center;gap:8px;font-size:1.25rem;font-weight:700;color:#fff;text-decoration:none;margin-right:auto;white-space:nowrap}.navbar-brand svg{width:28px;height:28px;color:#fff;flex-shrink:0}.nav-links{display:flex;gap:2px}.nav-link{display:flex;align-items:center;gap:4px;padding:6px 14px;border-radius:var(--radius-sm);font-size:.875rem;font-weight:500;color:#fffc;text-decoration:none;transition:all .15s;white-space:nowrap;cursor:pointer}.nav-link:hover,.nav-link.active{background:#ffffff26;color:#fff}.container{max-width:800px;margin:0 auto;padding:32px 16px 80px}h1{font-size:1.75rem;font-weight:700;margin-bottom:4px}h2{font-size:1.25rem;font-weight:700;margin-bottom:12px}h3{font-size:1.1rem;font-weight:600;margin-bottom:8px}p{color:var(--text-secondary)}.text-center{text-align:center}.mb-2{margin-bottom:8px}.mb-4{margin-bottom:16px}.mt-4{margin-top:16px}.card{background:var(--card-bg);border-radius:var(--radius);border:none;box-shadow:var(--shadow-lg);padding:24px;transition:box-shadow .2s;margin-bottom:24px}.btn{display:inline-flex;align-items:center;justify-content:center;gap:6px;padding:10px 24px;border-radius:var(--radius-pill);font-size:.875rem;font-weight:500;border:1px solid transparent;cursor:pointer;transition:all .15s;font-family:var(--font);text-decoration:none;line-height:1.8;white-space:nowrap;min-height:40px;width:100%}.btn:disabled{opacity:.5;cursor:not-allowed}.btn-primary{background:var(--primary);color:#fff;border-color:var(--primary)}.btn-primary:hover:not(:disabled){background:var(--primary-hover);border-color:var(--primary-hover)}.btn-secondary{background:var(--gray-100);color:var(--gray-700)}.btn-secondary:hover:not(:disabled){background:var(--gray-200)}.btn-success{background:var(--success);color:#fff;border-color:var(--success)}.btn-danger{background:var(--danger);color:#fff;border-color:var(--danger)}.input-group{margin-bottom:16px;text-align:left}.input-label{display:block;font-size:.875rem;font-weight:500;color:var(--gray-700);margin-bottom:8px}.input,.select{width:100%;padding:10px 14px;border:none;border-radius:var(--radius-sm);font-size:.875rem;font-family:var(--font);transition:all .15s;outline:none;background:var(--gray-100);color:var(--text-primary);min-height:40px}.input:focus,.select:focus{outline:2px solid var(--primary)}.options-list{display:flex;flex-direction:column;gap:10px;margin-top:16px}.option-btn{display:flex;align-items:center;width:100%;text-align:left;padding:14px 16px;border:1px solid var(--gray-200);border-radius:var(--radius-sm);background:var(--card-bg);cursor:pointer;font-size:1rem;font-family:var(--font);transition:all .15s;color:var(--text-primary)}.option-btn:hover:not(:disabled){border-color:var(--primary)}.option-btn.selected{border-color:var(--primary);background:var(--primary-light);color:var(--primary-dark);font-weight:500}.option-btn.correct{border-color:var(--success);background:var(--success-light);color:var(--success);font-weight:500}.option-btn.incorrect{border-color:var(--danger);background:var(--danger-light);color:var(--danger);font-weight:500}.explanation-box{padding:16px;border-radius:var(--radius-sm);margin-top:16px;font-size:.875rem;text-align:left}.explanation-box.correct{background:var(--success-light);border:1px solid #BBF7D0}.explanation-box.wrong{background:var(--danger-light);border:1px solid #FECACA}.explanation-box h4{font-size:1rem;margin-bottom:8px;font-weight:700}.loader{border:3px solid var(--gray-200);border-top:3px solid var(--primary);border-radius:50%;width:24px;height:24px;animation:spin 1s linear infinite;margin:0 auto}@keyframes spin{0%{transform:rotate(0)}to{transform:rotate(360deg)}}@keyframes fadeIn{0%{opacity:0;transform:translateY(10px)}to{opacity:1;transform:translateY(0)}}.animate-fade-in{animation:fadeIn .4s ease forwards}