:root{--primary-color: #667eea;--primary-hover: #5a5fdd;--secondary-color: #764ba2;--accent-color: #e63946;--text-primary: #333333;--text-secondary: #666666;--text-light: #999999;--background-primary: #ffffff;--background-secondary: #f5f7fa;--background-tertiary: #f9f9f9;--border-color: #e0e0e0;--success-color: #4CAF50;--warning-color: #FF9800;--error-color: #F44336;--font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "Roboto", "Oxygen", "Ubuntu", "Cantarell", "Fira Sans", "Droid Sans", "Helvetica Neue", sans-serif;--spacing-xs: 5px;--spacing-sm: 10px;--spacing-md: 20px;--spacing-lg: 30px;--spacing-xl: 40px;--radius-sm: 4px;--radius-md: 8px;--radius-lg: 10px;--radius-xl: 15px;--shadow-sm: 0 2px 4px rgba(0, 0, 0, .05);--shadow-md: 0 2px 10px rgba(0, 0, 0, .1);--shadow-lg: 0 4px 20px rgba(0, 0, 0, .15)}html{scroll-behavior:smooth}body{font-family:var(--font-family);font-size:16px;line-height:1.6;color:var(--text-primary);background-color:var(--background-secondary);-webkit-font-smoothing:antialiased;-moz-osx-font-smoothing:grayscale}a{color:var(--primary-color);text-decoration:none;transition:color .3s ease}a:hover{color:var(--primary-hover)}button{font-family:inherit;font-size:inherit;line-height:inherit;cursor:pointer;transition:all .3s ease;border:none;outline:none;padding:var(--spacing-sm) var(--spacing-md);border-radius:var(--radius-md)}button:focus{outline:2px solid var(--primary-color);outline-offset:2px}input,textarea,select{font-family:inherit;font-size:inherit;line-height:inherit;border:1px solid var(--border-color);border-radius:var(--radius-md);padding:var(--spacing-sm) var(--spacing-md);transition:border-color .3s ease;background-color:var(--background-primary);color:var(--text-primary)}input:focus,textarea:focus,select:focus{outline:none;border-color:var(--primary-color);box-shadow:0 0 0 2px #667eea1a}h1,h2,h3,h4,h5,h6{color:var(--text-primary);font-weight:600;line-height:1.3;margin-bottom:var(--spacing-md)}h1{font-size:2.5rem}h2{font-size:2rem}h3{font-size:1.5rem}h4{font-size:1.25rem}p{margin-bottom:var(--spacing-md);color:var(--text-secondary)}ul,ol{margin-left:var(--spacing-xl);margin-bottom:var(--spacing-md)}li{margin-bottom:var(--spacing-xs)}img{max-width:100%;height:auto;display:block}.container{width:100%;max-width:1200px;margin:0 auto;padding:0 var(--spacing-md)}.grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(300px,1fr));gap:var(--spacing-lg)}.flex{display:flex}.flex-column{flex-direction:column}.flex-center{display:flex;align-items:center;justify-content:center}.flex-between{display:flex;align-items:center;justify-content:space-between}.card{background-color:var(--background-primary);border-radius:var(--radius-lg);box-shadow:var(--shadow-md);overflow:hidden;transition:transform .3s ease,box-shadow .3s ease}.card:hover{transform:translateY(-5px);box-shadow:var(--shadow-lg)}.badge{display:inline-block;padding:var(--spacing-xs) var(--spacing-sm);border-radius:20px;font-size:.75rem;font-weight:500;background-color:var(--background-tertiary);color:var(--text-secondary)}.badge-primary{background-color:var(--primary-color);color:#fff}.divider{height:1px;background-color:var(--border-color);margin:var(--spacing-lg) 0}.text-center{text-align:center}.text-right{text-align:right}.mt-xs{margin-top:var(--spacing-xs)}.mt-sm{margin-top:var(--spacing-sm)}.mt-md{margin-top:var(--spacing-md)}.mt-lg{margin-top:var(--spacing-lg)}.mt-xl{margin-top:var(--spacing-xl)}.mb-xs{margin-bottom:var(--spacing-xs)}.mb-sm{margin-bottom:var(--spacing-sm)}.mb-md{margin-bottom:var(--spacing-md)}.mb-lg{margin-bottom:var(--spacing-lg)}.mb-xl{margin-bottom:var(--spacing-xl)}.p-xs{padding:var(--spacing-xs)}.p-sm{padding:var(--spacing-sm)}.p-md{padding:var(--spacing-md)}.p-lg{padding:var(--spacing-lg)}.p-xl{padding:var(--spacing-xl)}@media(max-width:768px){.hide-mobile{display:none!important}h1{font-size:2rem}h2{font-size:1.75rem}h3{font-size:1.25rem}}@media(min-width:769px){.hide-desktop{display:none!important}}@keyframes fadeIn{0%{opacity:0;transform:translateY(10px)}to{opacity:1;transform:translateY(0)}}.fade-in{animation:fadeIn .5s ease-out}@keyframes spin{to{transform:rotate(360deg)}}.loading{display:inline-block;width:20px;height:20px;border:2px solid var(--border-color);border-radius:50%;border-top-color:var(--primary-color);animation:spin .8s linear infinite}::-webkit-scrollbar{width:8px;height:8px}::-webkit-scrollbar-track{background:var(--background-tertiary)}::-webkit-scrollbar-thumb{background:var(--text-light);border-radius:4px}::-webkit-scrollbar-thumb:hover{background:var(--text-secondary)}*{margin:0;padding:0;box-sizing:border-box}body{font-family:-apple-system,BlinkMacSystemFont,Segoe UI,Roboto,Oxygen,Ubuntu,Cantarell,Fira Sans,Droid Sans,Helvetica Neue,sans-serif;-webkit-font-smoothing:antialiased;-moz-osx-font-smoothing:grayscale;background:#f5f7fa}.container{max-width:1200px;margin:0 auto;padding:10px 20px}.navbar{background:#fff;box-shadow:0 2px 10px #0000001a;position:sticky;top:0;z-index:1000}.navbar .container{display:flex;justify-content:space-between;align-items:center;padding:10px 20px}.logo{font-size:24px;font-weight:700}.logo a{color:#667eea;text-decoration:none}.nav-menu{display:flex;gap:30px 50px}.nav-item{text-decoration:none;color:#333;font-size:16px;font-family:Helvetica Neue,Helvetica,PingFang SC,Hiragino Sans GB,Microsoft YaHei,微软雅黑,Arial,sans-serif;letter-spacing:2px;transition:color .3s}.nav-item:hover{color:#667eea}.nav-item.active{color:#667eea;font-size:18px}.user-actions{display:flex;gap:15px}.btn-login,.btn-register{padding:3px 15px;border:none;border-radius:15px;font-size:12px;cursor:pointer;transition:all .3s}.btn-login{background:#f0f0f0;color:#333;border:1px solid #d0d0d0}.btn-login:hover{background:#e6f0ff;border-color:#667eea}.btn-register{background:#667eea;color:#fff}@keyframes flash-white{0%{background:#667eea}50%{background:#fff}to{background:#667eea}}.btn-register:hover{animation:flash-white .3s ease-in-out;color:#fff}.menu-toggle{display:none;background:none;border:none;font-size:24px;cursor:pointer}.mobile-menu{position:fixed;top:60px;left:0;width:100%;background:#fff;box-shadow:0 5px 10px #0000001a;z-index:999;padding:20px}.mobile-nav-item{display:block;padding:15px 0;text-decoration:none;color:#333;font-family:Helvetica Neue,Helvetica,PingFang SC,Hiragino Sans GB,Microsoft YaHei,微软雅黑,Arial,sans-serif;letter-spacing:2px;border-bottom:1px solid #f0f0f0}.mobile-nav-item:last-child{border-bottom:none}.mobile-user-actions{display:flex;gap:15px;margin-top:20px}.main-content{min-height:80vh;padding:0}.footer{background:#333;color:#fff;padding:40px 0 20px}.footer-content{display:grid;grid-template-columns:repeat(auto-fit,minmax(200px,1fr));gap:30px;margin-bottom:30px}.footer-col h3,.footer-col h4{margin-bottom:15px;color:#fff}.footer-col p{color:#ccc;line-height:1.6}.footer-col ul{list-style:none}.footer-col ul li{margin-bottom:10px}.footer-col ul li a{color:#ccc;text-decoration:none;transition:color .3s}.footer-col ul li a:hover{color:#667eea}.social-links{display:flex;gap:15px}.social-links a{color:#ccc;text-decoration:none;transition:color .3s}.social-links a:hover{color:#667eea}.footer-bottom{text-align:center;padding-top:20px;border-top:1px solid #444;color:#ccc}@media(max-width:768px){.nav-menu,.user-actions{display:none}.menu-toggle{display:block}.footer-content{grid-template-columns:1fr;text-align:center}.social-links{justify-content:center}}