.login-page{min-height:100vh;display:flex;align-items:center;justify-content:center;padding:var(--space-6);background:linear-gradient(135deg,#667eea,#764ba2);position:relative;overflow:hidden}.login-background{position:absolute;inset:0;overflow:hidden;pointer-events:none}.blob{position:absolute;border-radius:50%;filter:blur(60px);opacity:.3;animation:float 20s ease-in-out infinite}.blob-1{width:400px;height:400px;background:linear-gradient(135deg,#f093fb,#f5576c);top:-100px;right:-100px;animation-delay:0s}.blob-2{width:300px;height:300px;background:linear-gradient(135deg,#4facfe,#00f2fe);bottom:-50px;left:-50px;animation-delay:-7s}.blob-3{width:250px;height:250px;background:linear-gradient(135deg,#fa709a,#fee140);top:50%;left:50%;transform:translate(-50%,-50%);animation-delay:-14s}@keyframes float{0%,to{transform:translate(0) scale(1)}25%{transform:translate(20px,-30px) scale(1.05)}50%{transform:translate(-20px,20px) scale(.95)}75%{transform:translate(30px,10px) scale(1.02)}}.login-card{background:#fffffff2;-webkit-backdrop-filter:blur(20px);backdrop-filter:blur(20px);padding:var(--space-10);border-radius:var(--radius-xl);box-shadow:0 25px 50px -12px #00000040;width:100%;max-width:420px;position:relative;z-index:1;animation:slideUp .6s ease-out}@keyframes slideUp{0%{opacity:0;transform:translateY(30px)}to{opacity:1;transform:translateY(0)}}.login-header{text-align:center;margin-bottom:var(--space-8)}.logo-icon{width:64px;height:64px;margin:0 auto var(--space-4);background:linear-gradient(135deg,#667eea,#764ba2);border-radius:var(--radius-lg);display:flex;align-items:center;justify-content:center;color:#fff;box-shadow:0 10px 20px #667eea66}.logo-icon svg{width:36px;height:36px}.login-header h1{font-size:1.5rem;font-weight:700;color:var(--gray-900);margin-bottom:var(--space-2);background:linear-gradient(135deg,#667eea,#764ba2);-webkit-background-clip:text;-webkit-text-fill-color:transparent;background-clip:text}.login-header .subtitle{font-size:.875rem;color:var(--gray-500);line-height:1.6}.login-form{margin-bottom:var(--space-6)}.form-group{margin-bottom:var(--space-5)}.form-group label{display:block;font-size:.875rem;font-weight:600;color:var(--gray-700);margin-bottom:var(--space-2)}.input-wrapper{position:relative;display:flex;align-items:center}.input-icon{position:absolute;left:var(--space-3);width:20px;height:20px;color:var(--gray-400);pointer-events:none;transition:color var(--transition-base)}.input-wrapper input{width:100%;padding:var(--space-3) var(--space-4);padding-left:48px;border:2px solid var(--gray-200);border-radius:var(--radius-md);font-size:.9375rem;background:var(--gray-50);transition:all var(--transition-base)}.input-wrapper input::placeholder{color:var(--gray-400)}.input-wrapper input:hover{border-color:var(--gray-300);background:#fff}.input-wrapper input:focus{outline:none;border-color:#667eea;background:#fff;box-shadow:0 0 0 4px #667eea1a}.input-wrapper:focus-within .input-icon{color:#667eea}.input-wrapper.otp-input{display:flex}.input-wrapper.otp-input input{flex:1;padding-right:var(--space-3)}.otp-btn{padding:var(--space-2) var(--space-3);margin-left:var(--space-2);font-size:.8125rem;font-weight:600;color:#667eea;background:#667eea1a;border:1px solid rgba(102,126,234,.2);border-radius:var(--radius-md);cursor:pointer;transition:all var(--transition-base);white-space:nowrap;display:flex;align-items:center;gap:var(--space-1)}.otp-btn:hover:not(:disabled){background:#667eea33}.otp-btn:disabled{opacity:.5;cursor:not-allowed;background:var(--gray-100);border-color:var(--gray-200);color:var(--gray-400)}.spinner-sm{width:14px;height:14px;border:2px solid rgba(102,126,234,.3);border-top-color:#667eea;border-radius:50%;animation:spin .8s linear infinite}.login-tip{display:flex;align-items:center;justify-content:center;gap:var(--space-2);padding:var(--space-3);background:#667eea0d;border-radius:var(--radius-md);color:var(--gray-600);font-size:.8125rem;margin-top:var(--space-4)}.login-tip svg{color:#667eea;flex-shrink:0}.error-message{display:flex;align-items:center;gap:var(--space-2);padding:var(--space-3);background:var(--error-50);border:1px solid var(--error-100);border-radius:var(--radius-md);color:var(--error-600);font-size:.875rem;margin-bottom:var(--space-4);animation:shake .4s ease-in-out}.error-message svg{width:18px;height:18px;flex-shrink:0}.btn-submit{width:100%;padding:var(--space-4);font-size:1rem;font-weight:600;color:#fff;background:linear-gradient(135deg,#667eea,#764ba2);border:none;border-radius:var(--radius-md);cursor:pointer;transition:all var(--transition-base);box-shadow:0 4px 14px #667eea66;display:flex;align-items:center;justify-content:center;gap:var(--space-2)}.btn-submit:hover:not(:disabled){transform:translateY(-2px);box-shadow:0 6px 20px #667eea80}.btn-submit:active:not(:disabled){transform:translateY(0)}.btn-submit:disabled{opacity:.7;cursor:not-allowed}.login-footer{text-align:center;padding-top:var(--space-6);border-top:1px solid var(--gray-200)}.login-footer p{font-size:.875rem;color:var(--gray-600);margin:var(--space-3) 0 0 0}.login-footer button{background:none;border:none;color:#667eea;cursor:pointer;font-size:inherit;font-weight:600;padding:0;transition:color var(--transition-base)}.login-footer button:hover{color:#764ba2;text-decoration:underline}.forgot-link{margin-top:var(--space-4)!important}.form-title{text-align:center;font-size:1.125rem;font-weight:600;color:var(--gray-800);margin-bottom:var(--space-5)}@media(max-width:480px){.login-page{padding:var(--space-4)}.login-card{padding:var(--space-6)}.logo-icon{width:56px;height:56px}.logo-icon svg{width:28px;height:28px}.login-header h1{font-size:1.25rem}.login-header .subtitle{font-size:.8125rem}}.app{min-height:100vh;display:flex;flex-direction:column;background:var(--bg-primary)}.header{background:var(--bg-secondary);border-bottom:1px solid var(--gray-200);box-shadow:var(--shadow-sm);position:sticky;top:0;z-index:100}.header-content{max-width:1600px;margin:0 auto;padding:var(--space-4) var(--space-6);display:flex;align-items:center;justify-content:space-between}.header-left{display:flex;align-items:center;gap:var(--space-3)}.logo-small{width:40px;height:40px;background:linear-gradient(135deg,#667eea,#764ba2);border-radius:var(--radius-md);display:flex;align-items:center;justify-content:center;color:#fff;box-shadow:0 4px 12px #667eea4d}.logo-small svg{width:24px;height:24px}.header h1{font-size:1.25rem;font-weight:700;background:linear-gradient(135deg,#667eea,#764ba2);-webkit-background-clip:text;-webkit-text-fill-color:transparent;background-clip:text}.header-right{display:flex;align-items:center;gap:var(--space-3)}.user-info{display:flex;align-items:center;gap:var(--space-2);padding:var(--space-2) var(--space-3);background:var(--gray-50);border-radius:var(--radius-full)}.user-avatar{width:32px;height:32px;background:linear-gradient(135deg,#f093fb,#f5576c);border-radius:50%;display:flex;align-items:center;justify-content:center;color:#fff;font-weight:600;font-size:.875rem}.username{font-size:.875rem;font-weight:500;color:var(--gray-700)}.btn-logout{width:36px;height:36px;display:flex;align-items:center;justify-content:center;background:transparent;border:1px solid var(--gray-200);border-radius:var(--radius-md);cursor:pointer;transition:all var(--transition-base);color:var(--gray-500)}.btn-logout svg{width:18px;height:18px}.btn-logout:hover{background:var(--error-50);border-color:var(--error-500);color:var(--error-600)}.main{flex:1;display:flex;gap:var(--space-6);padding:var(--space-6);max-width:1600px;margin:0 auto;width:100%;overflow:hidden}.sidebar{width:380px;flex-shrink:0;display:flex;flex-direction:column;gap:var(--space-4);overflow-y:auto;max-height:calc(100vh - var(--space-12))}.sidebar-content{background:var(--bg-secondary);border-radius:var(--radius-xl);box-shadow:var(--shadow-md);padding:var(--space-6);display:flex;flex-direction:column;gap:var(--space-5)}.panel-section{display:flex;flex-direction:column;gap:var(--space-3)}.section-header{display:flex;align-items:center;gap:var(--space-2)}.section-header svg{width:18px;height:18px;color:var(--primary-500)}.section-header label{font-size:.875rem;font-weight:600;color:var(--gray-700)}.prompt-input{width:100%;padding:var(--space-3);border:2px solid var(--gray-200);border-radius:var(--radius-md);font-size:.875rem;resize:vertical;font-family:inherit;transition:all var(--transition-base);background:var(--gray-50)}.prompt-input::placeholder{color:var(--gray-400)}.prompt-input:hover{border-color:var(--gray-300)}.prompt-input:focus{outline:none;border-color:#667eea;background:#fff;box-shadow:0 0 0 4px #667eea1a}.shortcuts{display:grid;grid-template-columns:repeat(2,1fr);gap:var(--space-2)}.btn-shortcut{padding:var(--space-3) var(--space-3);font-size:.8125rem;font-weight:500;border:1px solid var(--gray-200);background:var(--gray-50);border-radius:var(--radius-md);cursor:pointer;transition:all var(--transition-base);display:flex;align-items:center;gap:var(--space-2);color:var(--gray-700)}.shortcut-icon{font-size:1rem}.btn-shortcut:hover{background:#fff;border-color:#667eea;color:#667eea;box-shadow:0 2px 8px #667eea26;transform:translateY(-1px)}.image-upload-section{display:flex;flex-direction:column;gap:var(--space-2)}.file-input-wrapper{position:relative}.file-input{position:absolute;width:.1px;height:.1px;opacity:0;overflow:hidden}.file-label{display:flex;align-items:center;gap:var(--space-2);padding:var(--space-3);border:2px dashed var(--gray-300);border-radius:var(--radius-md);cursor:pointer;transition:all var(--transition-base);font-size:.875rem;color:var(--gray-600);justify-content:center}.file-label svg{width:18px;height:18px}.file-label:hover{border-color:#667eea;background:var(--primary-50);color:#667eea}.hint-input{width:100%;padding:var(--space-2) var(--space-3);border:1px solid var(--gray-200);border-radius:var(--radius-md);font-size:.8125rem;transition:all var(--transition-base)}.hint-input:focus{outline:none;border-color:#667eea;box-shadow:0 0 0 3px #667eea1a}.btn-extend{display:flex;align-items:center;justify-content:center;gap:var(--space-2);padding:var(--space-3);font-size:.875rem;font-weight:600;background:linear-gradient(135deg,#22c55e,#16a34a);color:#fff;border:none;border-radius:var(--radius-md);cursor:pointer;transition:all var(--transition-base);box-shadow:0 4px 12px #22c55e4d}.btn-extend svg{width:16px;height:16px}.btn-extend:hover:not(:disabled){transform:translateY(-2px);box-shadow:0 6px 16px #22c55e66}.btn-extend:disabled{opacity:.6;cursor:not-allowed}.error-message{display:flex;align-items:center;gap:var(--space-2);padding:var(--space-3);background:var(--error-50);border:1px solid var(--error-100);border-radius:var(--radius-md);color:var(--error-600);font-size:.8125rem;animation:shake .4s ease-in-out}.error-message svg{width:16px;height:16px;flex-shrink:0}@keyframes shake{0%,to{transform:translate(0)}25%{transform:translate(-8px)}75%{transform:translate(8px)}}.spinner{width:18px;height:18px;border:2px solid rgba(255,255,255,.3);border-top-color:#fff;border-radius:50%;animation:spin .8s linear infinite}.spinner-small{width:14px;height:14px;border:2px solid rgba(255,255,255,.3);border-top-color:#fff;border-radius:50%;animation:spin .8s linear infinite}@keyframes spin{to{transform:rotate(360deg)}}.action-buttons{display:flex;flex-direction:column;gap:var(--space-3);margin-top:var(--space-2)}.btn-generate{display:flex;align-items:center;justify-content:center;gap:var(--space-2);padding:var(--space-4);font-size:1rem;font-weight:600;color:#fff;background:linear-gradient(135deg,#667eea,#764ba2);border:none;border-radius:var(--radius-lg);cursor:pointer;transition:all var(--transition-base);box-shadow:0 4px 14px #667eea66}.btn-generate svg{width:20px;height:20px}.btn-generate:hover:not(:disabled){transform:translateY(-2px);box-shadow:0 6px 20px #667eea80}.btn-generate:disabled{opacity:.7;cursor:not-allowed}.preview{flex:1;min-width:0;display:flex;flex-direction:column;gap:var(--space-4);max-height:calc(100vh - var(--space-12));overflow-y:auto}.preview-header{display:flex;align-items:center;justify-content:space-between;background:var(--bg-secondary);padding:var(--space-4) var(--space-5);border-radius:var(--radius-xl);box-shadow:var(--shadow-sm)}.preview-title{display:flex;align-items:center;gap:var(--space-3);font-size:.9375rem;font-weight:600;color:var(--gray-700)}.preview-title svg{width:18px;height:18px;color:var(--primary-500)}.question-count{font-size:.8125rem;color:var(--gray-500);background:var(--gray-100);padding:var(--space-1) var(--space-3);border-radius:var(--radius-full);white-space:nowrap}.preview-header-actions{display:flex;align-items:center;gap:var(--space-2)}.btn-icon-action{width:36px;height:36px;display:flex;align-items:center;justify-content:center;background:var(--gray-50);border:1px solid var(--gray-200);border-radius:var(--radius-md);cursor:pointer;transition:all var(--transition-base);color:var(--gray-600)}.btn-icon-action svg{width:18px;height:18px}.btn-icon-action:hover:not(:disabled){background:#fff;border-color:#667eea;color:#667eea;box-shadow:0 2px 8px #667eea26;transform:translateY(-1px)}.btn-icon-action:disabled{opacity:.5;cursor:not-allowed}.preview-card{flex:1;background:var(--bg-secondary);border-radius:var(--radius-xl);box-shadow:var(--shadow-md);padding:var(--space-6);min-height:0;overflow-y:auto}.placeholder{height:100%;min-height:400px;display:flex;flex-direction:column;align-items:center;justify-content:center;color:var(--gray-400);text-align:center}.placeholder-icon{width:80px;height:80px;margin-bottom:var(--space-4);background:var(--gray-100);border-radius:50%;display:flex;align-items:center;justify-content:center}.placeholder-icon svg{width:40px;height:40px;color:var(--gray-300)}.placeholder p{margin:0;font-size:1rem;color:var(--gray-400)}.placeholder-hint{font-size:.875rem;color:var(--gray-300);margin-top:var(--space-2)}.markdown-body{font-size:.9375rem;line-height:1.8;color:var(--gray-800);overflow-x:hidden;word-wrap:break-word;word-break:break-word;white-space:normal}.markdown-body :global(h1),.markdown-body :global(h2){margin:var(--space-5) 0 var(--space-3);font-size:1.1em;font-weight:600;color:var(--gray-900);word-wrap:break-word;max-width:100%}.markdown-body :global(p){margin:var(--space-2) 0;word-wrap:break-word;word-break:break-word}.markdown-body :global(ol),.markdown-body :global(ul){margin:var(--space-2) 0;padding-left:var(--space-6);max-width:100%;list-style-position:outside}.markdown-body :global(li){margin:var(--space-1) 0;word-wrap:break-word;word-break:break-word;max-width:100%;list-style-position:outside}.markdown-body :global(ol) :global(li),.markdown-body :global(ul) :global(li){display:list-item!important}@media print{.markdown-body :global(ol),.markdown-body :global(ul){list-style-type:decimal!important}.markdown-body :global(li){display:list-item!important;list-style-type:decimal!important}}.comparison-circle{display:inline-block;width:32px;height:32px;line-height:28px;text-align:center;border:2px solid var(--gray-700);border-radius:var(--radius-md);margin:0 var(--space-1);font-size:1rem;vertical-align:middle;background:#fff}.blank-line{display:inline-block;min-width:60px;border-bottom:2px solid var(--gray-700);margin:0 var(--space-1);height:24px;vertical-align:bottom}.blank-box{display:inline-block;min-width:24px;height:24px;border:1px solid var(--gray-500);margin:0 var(--space-1);vertical-align:middle;background:#fff;border-radius:var(--radius-sm)}.blank-parentheses{display:inline-block;min-width:36px;height:24px;border:1px solid var(--gray-500);border-radius:var(--radius-sm);margin:0 var(--space-1);vertical-align:baseline;background:#fff}.question-number{display:inline-block;min-width:28px;font-weight:600;color:var(--gray-700);margin-right:var(--space-1)}.markdown-body :global(img){max-width:200px;height:auto;margin:var(--space-2) 0;border:1px solid var(--gray-200);border-radius:var(--radius-md)}.answer-section{margin-top:var(--space-6);padding-top:var(--space-4);border-top:2px dashed var(--gray-200)}@media print{.sidebar,.header,.preview-header,.btn-icon-action,.preview-header-actions,.question-count{display:none!important}.main{padding:0;margin:0}.preview{width:100%;max-width:none}.preview-card{box-shadow:none;padding:0;border-radius:0;min-height:auto}.markdown-body{font-size:14px;line-height:1.8}.markdown-body :global(ol),.markdown-body :global(ul){display:block!important}.markdown-body :global(li){display:list-item!important}.markdown-body :global(ol){list-style-type:decimal!important;padding-left:2em}.question-number{display:inline-block!important;min-width:28px;font-weight:600;color:#000!important}.answer-section{display:block!important;page-break-before:always;margin-top:30px;padding-top:20px;border-top:2px dashed #000}body>*:not(#print-container){display:none!important}#print-container{position:absolute;top:0;left:0;width:100%}}@media(max-width:1024px){.main{flex-direction:column}.sidebar{width:100%}.shortcuts{grid-template-columns:repeat(3,1fr)}}@media(max-width:640px){.header-content{padding:var(--space-3) var(--space-4)}.header h1{font-size:1rem}.username{display:none}.main{padding:var(--space-4);gap:var(--space-4)}.sidebar-content{padding:var(--space-4)}.shortcuts{grid-template-columns:repeat(2,1fr)}.preview-card{padding:var(--space-4);min-height:300px}.preview-header{flex-wrap:wrap;gap:var(--space-3)}.preview-title{flex-wrap:wrap}.preview-header-actions{order:3;width:100%;justify-content:center;padding-top:var(--space-2);border-top:1px solid var(--gray-200);margin-top:var(--space-1)}.btn-icon-action{width:44px;height:44px}}:root{--primary-50: #fff7ed;--primary-100: #ffedd5;--primary-200: #fed7aa;--primary-300: #fdba74;--primary-400: #fb923c;--primary-500: #f97316;--primary-600: #ea580c;--primary-700: #c2410c;--secondary-50: #eff6ff;--secondary-100: #dbeafe;--secondary-200: #bfdbfe;--secondary-300: #93c5fd;--secondary-400: #60a5fa;--secondary-500: #3b82f6;--secondary-600: #2563eb;--secondary-700: #1d4ed8;--success-50: #f0fdf4;--success-100: #dcfce7;--success-500: #22c55e;--success-600: #16a34a;--error-50: #fef2f2;--error-100: #fee2e2;--error-500: #ef4444;--error-600: #dc2626;--gray-50: #f9fafb;--gray-100: #f3f4f6;--gray-200: #e5e7eb;--gray-300: #d1d5db;--gray-400: #9ca3af;--gray-500: #6b7280;--gray-600: #4b5563;--gray-700: #374151;--gray-800: #1f2937;--gray-900: #111827;--bg-primary: #fafafa;--bg-secondary: #ffffff;--bg-gradient: linear-gradient(135deg, #667eea 0%, #764ba2 100%);--bg-gradient-warm: linear-gradient(135deg, #f093fb 0%, #f5576c 100%);--bg-gradient-edu: linear-gradient(135deg, #fa709a 0%, #fee140 100%);--shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, .05);--shadow-md: 0 4px 6px -1px rgba(0, 0, 0, .1), 0 2px 4px -2px rgba(0, 0, 0, .1);--shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, .1), 0 4px 6px -4px rgba(0, 0, 0, .1);--shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, .1), 0 8px 10px -6px rgba(0, 0, 0, .1);--radius-sm: 6px;--radius-md: 10px;--radius-lg: 16px;--radius-xl: 24px;--radius-full: 9999px;--transition-fast: .15s ease;--transition-base: .2s ease;--transition-slow: .3s ease;--space-1: 4px;--space-2: 8px;--space-3: 12px;--space-4: 16px;--space-5: 20px;--space-6: 24px;--space-8: 32px;--space-10: 40px;--space-12: 48px}*,*: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,Roboto,Oxygen,Ubuntu,Cantarell,Fira Sans,Droid Sans,Helvetica Neue,Microsoft YaHei,PingFang SC,Hiragino Sans GB,sans-serif;background:var(--bg-primary);color:var(--gray-800);line-height:1.6;min-height:100vh}h1,h2,h3,h4,h5,h6{font-weight:600;line-height:1.3;color:var(--gray-900)}h1{font-size:1.75rem}h2{font-size:1.5rem}h3{font-size:1.25rem}p{margin-bottom:1rem}.sr-only{position:absolute;width:1px;height:1px;padding:0;margin:-1px;overflow:hidden;clip:rect(0,0,0,0);white-space:nowrap;border:0}.loading-page{min-height:100vh;display:flex;align-items:center;justify-content:center;background:linear-gradient(135deg,#667eea,#764ba2)}.loading-content{text-align:center;color:#fff}.loading-logo{width:80px;height:80px;margin:0 auto var(--space-6);background:#fff3;-webkit-backdrop-filter:blur(10px);backdrop-filter:blur(10px);border-radius:var(--radius-lg);display:flex;align-items:center;justify-content:center;animation:pulse 2s ease-in-out infinite}.loading-logo svg{width:48px;height:48px}@keyframes pulse{0%,to{transform:scale(1);opacity:1}50%{transform:scale(1.05);opacity:.8}}.loading-content p{font-size:1.25rem;font-weight:600;margin-bottom:var(--space-6);opacity:.95}.loading-spinner{width:32px;height:32px;margin:0 auto;border:3px solid rgba(255,255,255,.3);border-top-color:#fff;border-radius:50%;animation:spin .8s linear infinite}