:root {
            --primary-color: #004aad;
            --secondary-color: #0c0101;
            --dark-color: #000000;
            --light-color: #121212;
            --text-color: #000000;
            --text-light: #b0b0b0;
            --border-color: #2d2d2d;
            --shadow: 0 10px 30px rgba(0, 0, 0, 0.5);
            --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
        }
        
        * {
            margin: 0;
            padding: 0;
            box-sizing: border-box;
        }

      
        #three-background {
            position: fixed;
            top: 0;
            left: 0;
            width: 100%;
            height: 100%;
            z-index: -1;
            background-color: #ffffff;
        }

        body {
            font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'PingFang SC', 'Microsoft YaHei', sans-serif;
            line-height: 1.6;
            color: var(--text-color);
            background: transparent;
            min-height: 100vh;
            overflow-x: hidden;
        }
        
        .container {
            max-width: 1200px;
            margin: 0 auto;
            padding: 0 20px;
        }
        
       
        .navbar {
            background: transparent;
            position: static;
            transition: var(--transition);
        }

        .navbar.scrolled {
            padding: 10px 0;
        }
        
        .nav-container {
            display: flex;
            justify-content: space-between;
            align-items: center;
            padding: 20px 0;
            transition: var(--transition);
        }
        
        .logo {
            display: flex;
            align-items: center;
            gap: 10px;
            text-decoration: none;
            color: black;
            font-weight: 700;
            font-size: 1.5rem;
        }
        
        .logo-domain {
            color: var(--primary-color);
            font-weight: 800;
        }
        
        .nav-links {
            display: flex;
            gap: 30px;
            list-style: none;
        }
        
        .nav-links a {
            text-decoration: none;
            color: var(--primary-color);
            font-weight: 500;
            transition: var(--transition);
            position: relative;
        }
        
        .nav-links a:hover {
            color: black;
        }
        
        .nav-links a::after {
            content: '';
            position: absolute;
            bottom: -5px;
            left: 0;
            width: 0;
            height: 2px;
            background: var(--primary-color);
            transition: width 0.3s ease;
        }
        
        .nav-links a:hover::after {
            width: 100%;
        }
        
        .mobile-menu-btn {
            display: none;
            background: none;
            border: none;
            font-size: 1.5rem;
            color: rgb(255, 255, 255);
            cursor: pointer;
        }
        
       
        .hero {
            padding: 120px 0 100px;
            background: transparent;
            color: black;
            text-align: center;
            position: relative;
            overflow: hidden;
        }
        
        .hero::before {
            content: '';
            position: absolute;
            top: 0;
            left: 0;
            right: 0;
            bottom: 0;
            background: url('data:image/svg+xml,<svg xmlns=" http://www.w3.org/2000/svg " viewBox="0 0 100 100" preserveAspectRatio="none"><path d="M0,0 L100,0 L100,100 Z" fill="rgba(255,255,255,0.03)"/></svg>');
            background-size: cover;
        }
        
        .hero-content {
            position: relative;
            z-index: 2;
            max-width: 800px;
            margin: 0 auto;
        }
        
        .hero h1 {
            font-size: 3.5rem;
            font-weight: 800;
            margin-bottom: 1.5rem;
            line-height: 1.2;
        }
        
        .hero h1 .highlight {
            color: #004aad;
            text-shadow: 0 0 20px rgba(77, 171, 247, 0.3);
        }
        
        .hero p {
            font-size: 1.8rem;
            opacity: 0.9;
            margin-bottom: 2.5rem;
            line-height: 1.8;
            font-weight: bold;
        }
        
        .hero-cta {
            display: flex;
            gap: 20px;
            justify-content: center;
            margin-top: 3rem;
        }
        
        .btn {
            padding: 15px 35px;
            border-radius: 50px;
            text-decoration: none;
            font-weight: 600;
            font-size: 1.1rem;
            transition: var(--transition);
            display: inline-flex;
            align-items: center;
            gap: 10px;
        }
        
        .btn-primary {
            background: linear-gradient(135deg, var(--primary-color), #0d47a1);
            color: #fff;
            box-shadow: 0 5px 20px rgba(26, 115, 232, 0.3);
        }
        
        .btn-primary:hover {
            transform: translateY(-3px);
            box-shadow: 0 8px 25px rgba(26, 115, 232, 0.4);
        }
        
        .btn-secondary {
            background: rgba(255, 255, 255, 0.1);
            color: black;
            border: 1px solid black;
            backdrop-filter: blur(10px);
        }
        
        .btn-secondary:hover {
            background: rgba(255, 255, 255, 0.2);
            transform: translateY(-3px);
        }
        
       
        .features-section {
            padding: 150px 0;
            background: transparent;
        }
        
        .section-title {
            text-align: center;
            font-size: 2.5rem;
            color: black;
            margin-bottom: 3rem;
            position: relative;
        }
        

        
        .features-grid {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
            gap: 40px;
            margin-top: 50px;
        }
        
        .feature-card {
            background: transparent;
            border-radius: 15px;
            padding: 40px 30px;
            box-shadow: none;
            border: none;
            transition: var(--transition);
            position: relative;
            overflow: hidden;
            cursor: pointer;
        }
        
        .feature-card:hover {
            transform: translateY(-10px);
        }
        
        .feature-card:active {
            background: rgba(255, 255, 255, 0.05);
            box-shadow: 0 4px 15px rgba(0, 0, 0, 0.2);
        }
        

        
        .feature-icon {
            font-size: 3rem;
            color: var(--primary-color);
            margin-bottom: 25px;
            display: inline-block;
            width: 80px;
            height: 80px;
            background: rgba(26, 115, 232, 0.1);
            border-radius: 50%;
            display: flex;
            align-items: center;
            justify-content: center;
            transition: var(--transition);
        }
        
        .feature-card:hover .feature-icon {
            transform: scale(1.1);
            background: rgba(26, 115, 232, 0.15);
        }
        
        .feature-card h3 {
            font-size: 1.5rem;
            color: black;
            margin-bottom: 15px;
        }
        
        .feature-card p {
            color: var(--text-light);
            line-height: 1.7;
        }
        
        
        .demo-section {
            padding: 100px 0;
            background: transparent;
        }
        
        .demo-container {
            display: grid;
            grid-template-columns: 1fr 1fr;
            gap: 60px;
            align-items: center;
        }
        
        .demo-content h2 {
            font-size: 2.5rem;
            color: black;
            margin-bottom: 20px;
        }
        
        .demo-content p {
            color: var(--text-light);
            margin-bottom: 30px;
            font-size: 1.1rem;
            line-height: 1.8;
        }
        
        .demo-visual {
            position: relative;
        }
        
        .email-preview {
            background: rgba(255, 255, 255, 0);
            border-radius: 15px;
            padding: 30px;
            box-shadow: 0 15px 40px rgba(0, 0, 0, 0.3);
            border: none;
            backdrop-filter: blur(10px);
            transform: perspective(1000px) rotateY(-5deg);
            transition: var(--transition);
        }
        
        .email-preview:hover {
            transform: perspective(1000px) rotateY(0deg);
        }
        
        .email-header {
            display: flex;
            align-items: center;
            gap: 15px;
            margin-bottom: 25px;
            padding-bottom: 15px;
            border-bottom: 1px solid var(--border-color);
        }
        
        .email-avatar {
            width: 50px;
            height: 50px;
            border-radius: 50%;
            object-fit: cover;
            object-position: center;
        }
        
        .email-info h4 {
            color: black;
            margin-bottom: 5px;
        }

        .email-info p {
            color: var(--text-light);
            font-size: 0.9rem;
            margin: 0;
        }

        .email-body h3 {
            color: black;
            margin-bottom: 15px;
            font-size: 1.3rem;
        }

        .email-body p {
            color: var(--text-light);
            line-height: 1.6;
            margin-bottom: 20px;
        }
        
        .email-domain {
            display: inline-block;
            background: rgba(26, 115, 232, 0.1);
            color: var(--primary-color);
            padding: 8px 15px;
            border-radius: 20px;
            font-family: 'Courier New', monospace;
            font-weight: 600;
            margin-top: 10px;
            border: 1px solid rgba(26, 115, 232, 0.2);
        }
        
        
        .responsive-section {
            padding: 100px 0;
            background: transparent;
        }
        
        .responsive-demo {
            max-width: 800px;
            margin: 50px auto;
            position: relative;
        }
        
        .device-frame {
            background: #333;
            border-radius: 20px;
            padding: 20px;
            box-shadow: 0 20px 60px rgba(0, 0, 0, 0.2);
            margin: 0 auto;
            position: relative;
            overflow: hidden;
        }
        
        .device-screen {
            background: var(--light-color);
            border-radius: 10px;
            overflow: hidden;
            transition: all 0.5s ease;
        }
        
        .screen-content {
            padding: 30px;
            text-align: center;
        }
        
        .responsive-buttons {
            display: flex;
            justify-content: center;
            gap: 20px;
            margin-top: 30px;
        }
        
        .size-btn {
            padding: 10px 25px;
            background: var(--dark-color);
            border: 2px solid var(--border-color);
            border-radius: 25px;
            cursor: pointer;
            transition: var(--transition);
            font-weight: 500;
            color: black;
        }
        
        .size-btn.active {
            background: var(--primary-color);
            color: black;
            border-color: var(--primary-color);
        }
        
        .size-btn:hover {
            transform: translateY(-2px);
        }
        
        /* CTA区域 */
        .cta-section {
            padding: 100px 0;
            background: transparent;
            color: black;
            text-align: center;
            position: relative;
            overflow: hidden;
        }
        
        .cta-section::before {
            content: '';
            position: absolute;
            top: -50%;
            left: -50%;
            width: 200%;
            height: 200%;
            background: radial-gradient(circle, rgba(255,255,255,0.05) 1px, transparent 1px);
            background-size: 50px 50px;
            animation: float 20s linear infinite;
        }
        
        @keyframes float {
            0% { transform: rotate(0deg); }
            100% { transform: rotate(360deg); }
        }
        
        .cta-content {
            position: relative;
            z-index: 2;
            max-width: 1200px;
            margin: 0 auto;
        }
        
        .cta-content h2 {
            font-size: 3rem;
            margin-bottom: 20px;
        }
        
        .cta-content p {
            font-size: 1.2rem;
            opacity: 0.9;
            margin-bottom: 40px;
            line-height: 1.8;
        }

        
        .pricing-section {
            margin: 60px 0;
            padding: 50px;
            background: transparent;
            border-radius: 20px;
            border: none;
        }

        .pricing-section h3 {
            font-size: 1.8rem;
            color: black;
            margin-bottom: 25px;
            text-align: center;
            padding-bottom: 15px;
        }

       
        .accordion {
            max-width: 100%;
            margin: 0 auto;
        }

        .accordion-header {
            display: flex;
            justify-content: space-between;
            align-items: center;
            padding: 15px 20px;
            background: rgba(255, 255, 255, 0.1);
            backdrop-filter: blur(10px);
            border-radius: 10px;
            cursor: pointer;
            transition: all 0.3s ease;
            border: 1px solid rgba(255, 255, 255, 0.2);
        }

        .accordion-header:hover {
            background: rgba(255, 255, 255, 0.15);
        }

        .accordion-header span {
            font-size: 1.1rem;
            font-weight: 600;
            color: black;
        }

        .accordion-toggle {
            background: none;
            border: none;
            color: black;
            font-size: 1rem;
            cursor: pointer;
            padding: 5px;
            transition: transform 0.3s ease;
        }

        .accordion-content {
            max-height: 0;
            overflow: hidden;
            transition: max-height 0.3s ease;
            padding: 0 20px;
            margin: 10px 0;
        }

        .accordion-content.active {
            max-height: 800px;
            padding: 20px;
        }

        .accordion-toggle.active {
            transform: rotate(180deg);
        }

        .pricing-table {
            overflow-x: auto;
            max-width: 100%;
            margin: 0 auto;
            -webkit-overflow-scrolling: touch;
        }
        
        .pricing-table table {
            width: 100%;
            min-width: 600px;
            border-collapse: collapse;
            color: black;
        }

        .pricing-table th,
        .pricing-table td {
            padding: 15px 20px;
            text-align: center;
        }

        .pricing-table th {
            font-weight: 600;
            color: var(--primary-color);
        }

        
        .email-input-group {
            display: flex;
            max-width: 500px;
            margin: 40px auto;
            gap: 10px;
        }
        
        .email-input {
            flex: 1;
            padding: 15px 25px;
            border-radius: 50px;
            font-size: 1.1rem;
            background: rgba(255, 255, 255, 0.05);
            color: black;
            backdrop-filter: blur(10px);
            border-bottom: 2px solid rgb(17, 0, 0);
        }
        
        .email-input::placeholder {
            color: rgba(0, 0, 0, 0.7);
        }
        
        .email-input:focus {
            outline: none;
            border-color: var(--primary-color);
            background: rgba(255, 255, 255, 0.15);
        }
        
        
        .contact-wrapper {
            display: grid;
            grid-template-columns: 1fr 1fr;
            gap: 40px;
            max-width: 100%;
            margin: 40px 0;
            align-items: start;
        }
        
      
        .contact-form {
            max-width: 100%;
            margin: 0;
            padding: 0;
        }
        
       
        .contact-info {
            max-width: 100%;
            margin: 0;
            padding: 60px 50px;
        }
        
        .contact-info h3 {
            font-size: 1.8rem;
            color: black;
            margin-bottom: 25px;
            text-align: left;
            padding-bottom: 15px;
        }
        
        .contact-list {
            list-style: none;
            padding: 0;
            margin: 0;
        }
        
        .contact-list li {
            display: flex;
            flex-wrap: wrap;
            align-items: flex-start;
            gap: 15px;
            margin-bottom: 20px;
            color: black;
            font-size: 1.1rem;
            transition: all 0.3s ease;
        }
        
        .contact-list li div {
            flex: 1;
            min-width: 0;
        }
        
        .contact-list li:hover {
            color: var(--primary-color);
            transform: translateX(5px);
        }
        
        .contact-list li i {
            color: var(--primary-color);
            font-size: 1.3rem;
            width: 30px;
            text-align: center;
        }
        
        .contact-list li a {
            color: black;
            text-decoration: none;
            transition: color 0.3s ease;
        }
        
        .contact-list li:hover a {
            color: var(--primary-color);
        }
        
        .form-container {
            background: transparent;
            border-radius: 20px;
            padding: 60px 50px;
            backdrop-filter: blur(10px);
            transition: all 0.3s ease;
            position: relative;
            overflow: hidden;
        }
        
        .form-container::before {
            content: '';
            position: absolute;
            top: 0;
            left: -100%;
            width: 100%;
            height: 100%;
            background: linear-gradient(90deg, transparent, rgba(255, 255, 255, 0.02), transparent);
            transition: left 0.5s ease;
        }
        
        .form-container:hover::before {
            left: 100%;
        }
        
        .form-group {
            margin-bottom: 25px;
        }
        
        .hidden {
            display: none;
        }
        
        .form-input {
            width: 100%;
            padding: 15px 20px;
            border: none;
            border-radius: 8px;
            font-size: 1rem;
            background: rgba(255, 255, 255, 0.05);
            color: rgb(0, 0, 0);
            backdrop-filter: blur(10px);
            transition: all 0.3s ease;
            border: 1px solid rgb(17, 0, 0);
        }
        
        .form-input::placeholder {
            color: rgba(0, 0, 0, 0.5);
        }
        
        .form-input:focus {
            outline: none;
            background: rgba(255, 255, 255, 0.08);
        }
        
        .form-textarea {
            resize: vertical;
            min-height: 120px;
            font-family: inherit;
        }
        
        .form-submit {
            width: 100%;
            margin-top: 10px;
            padding: 15px 0;
            font-size: 1rem;
            font-weight: 600;
            border-radius: 8px;
            transition: all 0.3s ease;
            background: linear-gradient(135deg, var(--primary-color), #003d8a);
            border: none;
            color: rgb(255, 253, 253);
            box-shadow: 0 5px 15px rgba(0, 74, 173, 0.3);
            cursor: pointer;
            display: inline-flex;
            align-items: center;
            justify-content: center;
            gap: 10px;
        }
        
        .form-submit:hover {
            transform: translateY(-3px);
            box-shadow: 0 8px 25px rgba(0, 74, 173, 0.4);
            background: linear-gradient(135deg, #0056b3, #003d8a);
        }
        
        .form-submit:active {
            transform: translateY(-1px);
            box-shadow: 0 3px 10px rgba(0, 74, 173, 0.5);
        }
        
        /* 页脚 */
        .footer {
            background: transparent;
            color: black;
            padding: 60px 0 30px;
        }
        
        .footer-content {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
            gap: 40px;
            margin-bottom: 40px;
        }
        
        .footer-section h3 {
            font-size: 1.3rem;
            margin-bottom: 20px;
            color: black;
        }
        
        .footer-links {
            list-style: none;
        }
        
        .footer-links li {
            margin-bottom: 10px;
        }
        
        .footer-links a {
            color: rgba(0, 0, 0, 0.7);
            text-decoration: none;
            transition: var(--transition);
        }
        
        .footer-links a:hover {
            color: black;
            padding-left: 5px;
        }
        
        .copyright {
            text-align: center;
            padding-top: 30px;
            border-top: 1px solid rgba(0, 0, 0, 0.1);
            color: rgba(0, 0, 0, 0.5);
            font-size: 0.9rem;
        }
        
     
        @media screen and (max-width: 768px) {
            .hero h1 {
                font-size: 2.5rem;
            }
            
            .hero p {
                font-size: 1.1rem;
            }
            
            .nav-links {
                display: none;
            }
            
            .mobile-menu-btn {
            display: block;
            margin-right: 15px; 
            color: var(--primary-color);
        }
        
        
        .nav-links.mobile {
            display: flex;
            background: rgba(255, 253, 253, 0.7);
            backdrop-filter: blur(10px);
            border-radius: 8px;
            padding: 20px;
            flex-direction: column;
            gap: 15px;
            position: absolute;
            top: 70px;
            right: 20px;
            z-index: 1000;
        }
            
            .demo-container {
                grid-template-columns: 1fr;
            }
            
            .email-preview {
                transform: none;
            }
            
            .features-grid {
                grid-template-columns: 1fr;
            }
            
            .hero-cta {
                flex-direction: column;
                align-items: center;
            }
            
            .btn {
                width: 100%;
                max-width: 300px;
                justify-content: center;
            }
            
            .email-input-group {
                flex-direction: column;
            }
            
            .email-input {
                width: 100%;
            }
            
            /* 联系表单响应式 */
            .contact-wrapper {
                grid-template-columns: 1fr;
                gap: 30px;
            }
            
            .form-container,
            .info-container {
                padding: 30px 20px;
            }
            
           
            .pricing-section {
                padding: 30px 20px;
            }
            
            .pricing-section h3 {
                font-size: 1.4rem;
            }
            
            .pricing-table th,
            .pricing-table td {
                font-size: 1rem;
                padding: 12px 15px;
            }
        }
        
        @media screen and (max-width: 480px) {
            .hero h1 {
                font-size: 2rem;
            }
            
            .section-title {
                font-size: 2rem;
            }
            
            .feature-card {
                padding: 30px 20px;
            }
            
            
            .pricing-table th,
            .pricing-table td {
                font-size: 1rem;
                padding: 10px 12px;
            }
        }
        
       
        @keyframes fadeInUp {
            from {
                opacity: 0;
                transform: translateY(30px);
            }
            to {
                opacity: 1;
                transform: translateY(0);
            }
        }
        
        .animate-fadeInUp {
            animation: fadeInUp 0.6s ease forwards;
        }
        
        .animate-delay-1 {
            animation-delay: 0.2s;
        }
        
        .animate-delay-2 {
            animation-delay: 0.4s;
        }

        
        .back-to-top {
            position: fixed;
            bottom: 30px;
            right: 30px;
            z-index: 999;
            opacity: 0;
            transition: opacity 0.3s ease;
        }
        .back-to-top a {
            display: inline-block;
            width: 50px;
            height: 50px;
            background: var(--primary-color);
            color: black;
            border-radius: 50%;
            text-align: center;
            line-height: 50px;
            font-size: 1.2rem;
            box-shadow: 0 4px 12px rgba(0, 74, 173, 0.3);
            transition: transform 0.3s ease;
        }
        .back-to-top a:hover {
            transform: translateY(-3px);
            box-shadow: 0 6px 16px rgba(0, 74, 173, 0.4);
        }
        
        body.scrolled .back-to-top {
            opacity: 1;
        }

        .animate-delay-3 {
            animation-delay: 0.6s;
        }


.domain-shapes-container {
    display: flex;
    align-items: center;
    gap: 15px;
    margin: 20px 0;
}


.shapes-container {
    display: flex;
    gap: 8px;
    align-items: center;
}

.shape {
    width: 24px;
    height: 24px;
}

.circle {
    background-color: var(--primary-color);
    border-radius: 50%;
}

.triangle {
    width: 0;
    height: 0;
    border-left: 12px solid transparent;
    border-right: 12px solid transparent;
    border-bottom: 24px solid var(--primary-color);
}

.square {
    background-color: var(--primary-color);
}