* { margin: 0; padding: 0; box-sizing: border-box; }
        
        /* ========== 全局样式 ========== */
        :root {
            --primary: linear-gradient(135deg, #ff6b00 0%, #ff8533 100%);
            --primary-dark: #e65c00;
            --secondary: #667eea;
            --success: #52c41a;
            --danger: #ff4d4f;
            --warning: #faad14;
            --text-primary: #1a1a2e;
            --text-secondary: #4a4a6a;
            --text-muted: #9090a0;
            --bg-light: #f8f9fc;
            --bg-white: #ffffff;
            --shadow-sm: 0 2px 8px rgba(0,0,0,0.06);
            --shadow-md: 0 4px 20px rgba(0,0,0,0.08);
            --shadow-lg: 0 8px 40px rgba(0,0,0,0.12);
            --shadow-glow: 0 8px 30px rgba(255,107,0,0.25);
        }
        
        body { 
            font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, 'Noto Sans', sans-serif;
            background: var(--bg-light);
            color: var(--text-primary);
            line-height: 1.6;
            overflow-x: hidden;
        }
        
        a { text-decoration: none; color: inherit; }
        
        /* ========== 顶部导航 ========== */
        .task-nav {
            background: rgba(255,255,255,0.98);
            backdrop-filter: blur(20px);
            box-shadow: 0 2px 20px rgba(0,0,0,0.06);
            position: sticky;
            top: 0;
            z-index: 1000;
        }
        
        .nav-container {
            max-width: 1400px;
            margin: 0 auto;
            padding: 0 40px;
            height: 72px;
            display: flex;
            align-items: center;
            justify-content: space-between;
        }
        
        .nav-left {
            display: flex;
            align-items: center;
            gap: 20px;
        }
        
        .nav-logo {
            display: flex;
            align-items: center;
            gap: 12px;
            cursor: pointer;
        }
        
        .logo-icon {
            width: 44px;
            height: 44px;
            background: var(--primary);
            border-radius: 12px;
            display: flex;
            align-items: center;
            justify-content: center;
            color: #fff;
            font-size: 20px;
            box-shadow: 0 4px 15px rgba(255,107,0,0.3);
        }
        
        .logo-text {
            font-size: 22px;
            font-weight: 700;
            color: var(--text-primary);
        }
        
        .logo-text span {
            background: var(--primary);
            -webkit-background-clip: text;
            -webkit-text-fill-color: transparent;
            background-clip: text;
        }
        
        .nav-menu {
            display: flex;
            align-items: center;
            gap: 8px;
            list-style: none;
        }
        
        .nav-menu-item {
            padding: 10px 20px;
            font-size: 15px;
            font-weight: 500;
            color: var(--text-secondary);
            border-radius: 8px;
            transition: all 0.3s;
            cursor: pointer;
        }
        
        .nav-menu-item:hover,
        .nav-menu-item.active {
            color: var(--primary-dark);
            background: rgba(255,107,0,0.06);
        }
        
        .nav-menu-item.active::after {
            content: '';
            position: absolute;
            bottom: -4px;
            left: 50%;
            transform: translateX(-50%);
            width: 20px;
            height: 3px;
            background: var(--primary);
            border-radius: 2px;
        }
        
        .nav-right {
            display: flex;
            align-items: center;
            gap: 16px;
        }
        
        .nav-btn {
            padding: 10px 24px;
            border-radius: 10px;
            font-size: 14px;
            font-weight: 600;
            cursor: pointer;
            transition: all 0.3s;
            border: none;
        }
        
        .nav-btn-outline {
            background: transparent;
            border: 2px solid #e8e8ee;
            color: var(--text-secondary);
        }
        
        .nav-btn-outline:hover {
            border-color: var(--primary-dark);
            color: var(--primary-dark);
        }
        
        .nav-btn-primary {
            background: var(--primary);
            color: #fff;
            box-shadow: 0 4px 15px rgba(255,107,0,0.3);
        }
        
        .nav-btn-primary:hover {
            transform: translateY(-2px);
            box-shadow: 0 6px 20px rgba(255,107,0,0.4);
        }
        
        .nav-user {
            width: 40px;
            height: 40px;
            background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
            border-radius: 50%;
            display: flex;
            align-items: center;
            justify-content: center;
            color: #fff;
            font-size: 16px;
            cursor: pointer;
        }
        /* ========== 底部 ========== */
        .site-footer {
            background: linear-gradient(180deg, #f8f9fc 0%, #eaeef5 100%);
            margin-top: 60px;
            padding: 50px 0 30px;
            border-top: 1px solid #f0f0f5;
        }
        
        .footer-container {
            max-width: 1400px;
            margin: 0 auto;
            padding: 0 40px;
        }
        
        .footer-main {
            display: grid;
            grid-template-columns: 2fr 1fr 1fr 1fr;
            gap: 50px;
            margin-bottom: 40px;
        }
        
        .footer-brand {
            display: flex;
            flex-direction: column;
            gap: 16px;
        }
        
        .footer-logo {
            display: flex;
            align-items: center;
            gap: 12px;
        }
        
        .footer-logo-icon {
            width: 44px;
            height: 44px;
            background: var(--primary);
            border-radius: 12px;
            display: flex;
            align-items: center;
            justify-content: center;
            color: #fff;
            font-size: 20px;
        }
        
        .footer-logo-text {
            font-size: 20px;
            font-weight: 700;
            color: var(--text-primary);
        }
        
        .footer-desc {
            font-size: 13px;
            color: var(--text-muted);
            line-height: 1.8;
        }
        
        .footer-social {
            display: flex;
            gap: 12px;
            margin-top: 8px;
        }
        
        .social-link {
            width: 36px;
            height: 36px;
            background: var(--bg-white);
            border-radius: 10px;
            display: flex;
            align-items: center;
            justify-content: center;
            color: var(--text-muted);
            transition: all 0.3s;
            box-shadow: 0 2px 8px rgba(0,0,0,0.04);
        }
        
        .social-link:hover {
            background: var(--primary);
            color: #fff;
            transform: translateY(-2px);
        }
        
        .footer-column h4 {
            font-size: 15px;
            font-weight: 600;
            color: var(--text-primary);
            margin-bottom: 20px;
        }
        
        .footer-links {
            display: flex;
            flex-direction: column;
            gap: 12px;
        }
        
        .footer-link {
            font-size: 13px;
            color: var(--text-muted);
            transition: color 0.3s;
        }
        
        .footer-link:hover {
            color: var(--primary-dark);
        }
        
        .footer-bottom {
            padding-top: 30px;
            border-top: 1px solid #e8e8ee;
            display: flex;
            justify-content: space-between;
            align-items: center;
        }
        
        .footer-copyright {
            font-size: 12px;
            color: var(--text-muted);
        }
        
        .footer-legal {
            display: flex;
            gap: 24px;
        }
        
        .footer-legal a {
            font-size: 12px;
            color: var(--text-muted);
            transition: color 0.3s;
        }
        
        .footer-legal a:hover {
            color: var(--primary-dark);
        }
        @media (max-width: 900px) {
            .footer-container {
                padding-left: 20px;
                padding-right: 20px;
            }
            
            .nav-menu {
                display: none;
            }
            
           
            .footer-main {
                grid-template-columns: 1fr 1fr;
            }
        }