:root {
    --primary: #1E6FD9;
    --primary-dark: #1557A8;
    --primary-light: #4A90E2;
    --gradient-start: #1E6FD9;
    --gradient-end: #6B4FE3;
    --gradient: linear-gradient(135deg, var(--gradient-start), var(--gradient-end));
    --text-primary: #1A1A2E;
    --text-secondary: #4A4A68;
    --text-muted: #8888A0;
    --bg-white: #FFFFFF;
    --bg-light: #F8F9FC;
    --bg-dark: #0D1B2A;
    --border-light: #E8EAF0;
    --success: #22C55E;
    --warning: #F59E0B;
    --danger: #EF4444;
    --radius: 8px;
    --radius-lg: 16px;
    --shadow-sm: 0 1px 3px rgba(0,0,0,0.08);
    --shadow-md: 0 4px 12px rgba(0,0,0,0.1);
    --shadow-lg: 0 8px 30px rgba(0,0,0,0.12);
    --transition: all 0.3s ease;
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, "PingFang SC", "Microsoft YaHei", sans-serif;
    font-size: 16px;
    line-height: 1.7;
    color: var(--text-primary);
    background: var(--bg-white);
}

.container {
    width: 100%;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

img {
    max-width: 100%;
    height: auto;
}

a {
    color: var(--primary);
    text-decoration: none;
    transition: var(--transition);
}

a:hover {
    color: var(--primary-dark);
}

.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 12px 28px;
    font-size: 15px;
    font-weight: 500;
    border-radius: var(--radius);
    border: none;
    cursor: pointer;
    transition: var(--transition);
    text-decoration: none;
}

.btn-primary {
    background: var(--gradient);
    color: white;
    box-shadow: 0 4px 15px rgba(30, 111, 217, 0.3);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(30, 111, 217, 0.4);
    color: white;
}

.btn-outline {
    background: transparent;
    color: var(--primary);
    border: 2px solid var(--primary);
}

.btn-outline:hover {
    background: var(--primary);
    color: white;
}

.btn-danger {
    background: var(--danger);
    color: white;
}

.btn-danger:hover {
    background: #DC2626;
    color: white;
}

.btn-lg {
    padding: 16px 36px;
    font-size: 17px;
}

.header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    box-shadow: var(--shadow-sm);
}

.header-inner {
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 70px;
}

.logo {
    display: flex;
    align-items: center;
    gap: 10px;
    font-size: 22px;
    font-weight: 700;
    color: var(--text-primary);
}

.logo:hover {
    color: var(--text-primary);
}

.logo-img {
    width: 40px;
    height: 40px;
    border-radius: var(--radius);
}

.mobile-menu-btn {
    display: none;
    flex-direction: column;
    gap: 5px;
    padding: 10px;
    background: none;
    border: none;
    cursor: pointer;
}

.mobile-menu-btn span {
    display: block;
    width: 24px;
    height: 2px;
    background: var(--text-primary);
    transition: var(--transition);
}

.nav-list {
    display: flex;
    align-items: center;
    gap: 8px;
    list-style: none;
}

.nav-list a {
    padding: 8px 14px;
    font-size: 14px;
    color: var(--text-secondary);
    border-radius: var(--radius);
}

.nav-list a:hover {
    color: var(--primary);
    background: rgba(30, 111, 217, 0.08);
}

.nav-cta {
    background: var(--gradient) !important;
    color: white !important;
}

.nav-cta:hover {
    opacity: 0.9;
    background: var(--gradient) !important;
}

.hero {
    position: relative;
    min-height: 100vh;
    display: flex;
    align-items: center;
    padding: 120px 0 80px;
    overflow: hidden;
}

.hero-bg {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    z-index: -1;
}

.hero-video {
    width: 100%;
    height: 100%;
    object-fit: cover;
}

.hero-overlay {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: linear-gradient(135deg, rgba(13, 27, 42, 0.85), rgba(30, 111, 217, 0.75));
}

.hero-content {
    position: relative;
    text-align: center;
    color: white;
}

.hero h1 {
    font-size: 48px;
    font-weight: 700;
    line-height: 1.2;
    margin-bottom: 20px;
}

.hero-subtitle {
    font-size: 20px;
    opacity: 0.9;
    max-width: 700px;
    margin: 0 auto 40px;
}

.hero-buttons {
    display: flex;
    gap: 16px;
    justify-content: center;
    flex-wrap: wrap;
    margin-bottom: 60px;
}

.hero-buttons .btn-outline {
    border-color: rgba(255,255,255,0.5);
    color: white;
}

.hero-buttons .btn-outline:hover {
    background: rgba(255,255,255,0.15);
    border-color: white;
}

.hero-stats {
    display: flex;
    justify-content: center;
    gap: 60px;
}

.stat-item {
    text-align: center;
}

.stat-num {
    display: block;
    font-size: 36px;
    font-weight: 700;
}

.stat-label {
    font-size: 14px;
    opacity: 0.8;
}

section {
    padding: 100px 0;
}

section h2 {
    font-size: 36px;
    font-weight: 700;
    text-align: center;
    margin-bottom: 16px;
}

.section-desc {
    text-align: center;
    color: var(--text-secondary);
    max-width: 600px;
    margin: 0 auto 50px;
}

.downloads {
    background: var(--bg-light);
}

.download-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 24px;
    margin-bottom: 40px;
}

.download-card {
    background: white;
    padding: 32px 24px;
    border-radius: var(--radius-lg);
    text-align: center;
    box-shadow: var(--shadow-sm);
    transition: var(--transition);
}

.download-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-lg);
}

.download-icon {
    width: 60px;
    height: 60px;
    margin: 0 auto 20px;
    color: var(--primary);
}

.download-icon svg {
    width: 100%;
    height: 100%;
}

.download-card h3 {
    font-size: 20px;
    margin-bottom: 12px;
}

.download-card p {
    color: var(--text-secondary);
    font-size: 14px;
    margin-bottom: 16px;
}

.version-tag {
    display: inline-block;
    padding: 4px 12px;
    background: rgba(30, 111, 217, 0.1);
    color: var(--primary);
    font-size: 12px;
    border-radius: 20px;
    margin-bottom: 20px;
}

.download-notice {
    display: flex;
    align-items: flex-start;
    gap: 16px;
    padding: 20px 24px;
    background: rgba(245, 158, 11, 0.1);
    border-left: 4px solid var(--warning);
    border-radius: var(--radius);
    margin-bottom: 40px;
}

.notice-icon {
    font-size: 24px;
}

.notice-content {
    font-size: 14px;
    color: var(--text-secondary);
}

.notice-content strong {
    color: var(--text-primary);
}

.version-history {
    text-align: center;
    padding: 40px;
    background: white;
    border-radius: var(--radius-lg);
}

.version-history h3 {
    font-size: 22px;
    margin-bottom: 12px;
}

.version-history p {
    color: var(--text-secondary);
    margin-bottom: 20px;
}

.features-showcase {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 60px;
    align-items: center;
    margin-bottom: 80px;
}

.feature-main img {
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-lg);
}

.feature-list {
    display: flex;
    flex-direction: column;
    gap: 24px;
}

.feature-item {
    display: flex;
    gap: 20px;
    padding: 20px;
    background: var(--bg-light);
    border-radius: var(--radius);
    transition: var(--transition);
}

.feature-item:hover {
    background: white;
    box-shadow: var(--shadow-md);
}

.feature-icon {
    font-size: 32px;
    flex-shrink: 0;
}

.feature-text h3 {
    font-size: 18px;
    margin-bottom: 8px;
}

.feature-text p {
    color: var(--text-secondary);
    font-size: 14px;
}

.compare-section {
    text-align: center;
}

.compare-section h3 {
    font-size: 24px;
    margin-bottom: 30px;
}

.compare-table-wrapper {
    overflow-x: auto;
    margin-bottom: 24px;
}

.compare-table {
    width: 100%;
    border-collapse: collapse;
    background: white;
    border-radius: var(--radius);
    overflow: hidden;
    box-shadow: var(--shadow-sm);
}

.compare-table th,
.compare-table td {
    padding: 16px 24px;
    text-align: center;
    border-bottom: 1px solid var(--border-light);
}

.compare-table th {
    background: var(--bg-light);
    font-weight: 600;
}

.compare-table th:nth-child(2) {
    background: rgba(30, 111, 217, 0.1);
    color: var(--primary);
}

.compare-table td:nth-child(2) {
    background: rgba(30, 111, 217, 0.03);
}

.compare-note {
    color: var(--text-secondary);
    font-size: 14px;
    margin-bottom: 20px;
}

.tutorial {
    background: var(--bg-light);
}

.tutorial-grid {
    display: grid;
    grid-template-columns: 400px 1fr;
    gap: 60px;
    align-items: center;
    margin-bottom: 60px;
}

.phone-mockup {
    background: transparent;
    padding: 0;
    border-radius: 0;
    box-shadow: none;
}

.phone-screen {
    position: relative;
    border-radius: 16px;
    overflow: hidden;
    aspect-ratio: 9/16;
    box-shadow: var(--shadow-lg);
}

.app-screenshot {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    object-fit: cover;
    opacity: 0;
    transition: opacity 0.5s ease;
}

.app-screenshot.active {
    opacity: 1;
}

.screenshot-dots {
    display: flex;
    justify-content: center;
    gap: 10px;
    margin-top: 20px;
}

.dot {
    width: 10px;
    height: 10px;
    border-radius: 50%;
    background: var(--border-light);
    cursor: pointer;
    transition: var(--transition);
}

.dot.active {
    background: var(--primary);
    width: 30px;
    border-radius: 5px;
}

.tutorial-steps {
    display: flex;
    flex-direction: column;
    gap: 20px;
}

.step-card {
    display: flex;
    gap: 20px;
    padding: 24px;
    background: white;
    border-radius: var(--radius);
    box-shadow: var(--shadow-sm);
    transition: var(--transition);
}

.step-card:hover {
    box-shadow: var(--shadow-md);
}

.step-number {
    font-size: 32px;
    font-weight: 700;
    color: var(--primary);
    opacity: 0.3;
}

.step-content h3 {
    font-size: 18px;
    margin-bottom: 8px;
}

.step-content p {
    color: var(--text-secondary);
    font-size: 14px;
}

.tutorial-topics h3 {
    font-size: 24px;
    text-align: center;
    margin-bottom: 30px;
}

.topic-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 20px;
    margin-bottom: 30px;
}

.topic-card {
    padding: 24px;
    background: white;
    border-radius: var(--radius);
    text-align: center;
    box-shadow: var(--shadow-sm);
}

.topic-icon {
    font-size: 36px;
    display: block;
    margin-bottom: 12px;
}

.topic-card h4 {
    font-size: 16px;
    margin-bottom: 8px;
}

.topic-card p {
    color: var(--text-secondary);
    font-size: 13px;
}

.tutorial-cta {
    text-align: center;
    color: var(--text-secondary);
    margin-bottom: 20px;
}

.security-hero {
    display: grid;
    grid-template-columns: 400px 1fr;
    gap: 60px;
    align-items: center;
    margin-bottom: 80px;
}

.security-hero img {
    border-radius: var(--radius-lg);
}

.security-intro h3 {
    font-size: 28px;
    margin-bottom: 16px;
}

.security-intro > p {
    color: var(--text-secondary);
    margin-bottom: 24px;
}

.security-features {
    list-style: none;
}

.security-features li {
    padding: 12px 0;
    border-bottom: 1px solid var(--border-light);
    font-size: 15px;
}

.risk-alerts {
    margin-bottom: 60px;
}

.risk-alerts h3 {
    font-size: 24px;
    text-align: center;
    margin-bottom: 30px;
}

.alert-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 24px;
}

.alert-card {
    padding: 24px;
    border-radius: var(--radius);
    background: white;
    box-shadow: var(--shadow-sm);
}

.alert-card.danger {
    border-left: 4px solid var(--danger);
}

.alert-card.warning {
    border-left: 4px solid var(--warning);
}

.alert-header {
    display: flex;
    align-items: center;
    gap: 12px;
    margin-bottom: 12px;
}

.alert-icon {
    font-size: 24px;
}

.alert-header h4 {
    font-size: 18px;
}

.alert-card p {
    color: var(--text-secondary);
    font-size: 14px;
}

.emergency-section {
    background: rgba(239, 68, 68, 0.05);
    padding: 40px;
    border-radius: var(--radius-lg);
    margin-bottom: 60px;
}

.emergency-section h3 {
    font-size: 24px;
    margin-bottom: 20px;
    color: var(--danger);
}

.emergency-steps {
    margin: 20px 0;
    padding-left: 24px;
}

.emergency-steps li {
    padding: 8px 0;
    color: var(--text-secondary);
}

.emergency-note {
    color: var(--text-secondary);
    margin-bottom: 20px;
}

.verify-section {
    text-align: center;
    padding: 40px;
    background: var(--bg-light);
    border-radius: var(--radius-lg);
}

.verify-section h3 {
    font-size: 24px;
    margin-bottom: 16px;
}

.verify-section > p {
    color: var(--text-secondary);
    margin-bottom: 30px;
}

.verify-methods {
    display: flex;
    justify-content: center;
    gap: 40px;
    margin-bottom: 30px;
}

.verify-item {
    display: flex;
    align-items: center;
    gap: 10px;
    font-size: 15px;
}

.verify-icon {
    font-size: 24px;
}

.faq {
    background: var(--bg-light);
}

.faq-list {
    max-width: 800px;
    margin: 0 auto 40px;
}

.faq-item {
    background: white;
    border-radius: var(--radius);
    margin-bottom: 12px;
    overflow: hidden;
    box-shadow: var(--shadow-sm);
}

.faq-question {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 20px 24px;
    cursor: pointer;
    font-weight: 500;
    transition: var(--transition);
}

.faq-question:hover {
    background: var(--bg-light);
}

.faq-toggle {
    font-size: 24px;
    color: var(--primary);
    transition: var(--transition);
}

.faq-item.active .faq-toggle {
    transform: rotate(45deg);
}

.faq-answer {
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.3s ease;
}

.faq-item.active .faq-answer {
    max-height: 500px;
}

.faq-answer p {
    padding: 0 24px 20px;
    color: var(--text-secondary);
    line-height: 1.8;
}

.faq-cta {
    text-align: center;
}

.faq-cta p {
    color: var(--text-secondary);
    margin-bottom: 20px;
}

.news-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 30px;
    margin-bottom: 40px;
}

.news-card {
    padding: 30px;
    background: var(--bg-light);
    border-radius: var(--radius);
    transition: var(--transition);
}

.news-card:hover {
    background: white;
    box-shadow: var(--shadow-md);
}

.news-date {
    font-size: 13px;
    color: var(--text-muted);
    margin-bottom: 12px;
}

.news-card h3 {
    font-size: 18px;
    margin-bottom: 12px;
    line-height: 1.4;
}

.news-card p {
    color: var(--text-secondary);
    font-size: 14px;
    margin-bottom: 16px;
}

.news-link {
    font-size: 14px;
    font-weight: 500;
}

.news-cta {
    text-align: center;
}

.news-cta p {
    color: var(--text-secondary);
    margin-bottom: 20px;
}

.about-content {
    display: grid;
    grid-template-columns: 1fr 400px;
    gap: 60px;
    align-items: center;
    margin-bottom: 60px;
}

.about-text h2 {
    text-align: left;
    margin-bottom: 24px;
}

.about-text p {
    color: var(--text-secondary);
    margin-bottom: 16px;
}

.about-image img {
    border-radius: var(--radius-lg);
}

.brand-values {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 30px;
}

.value-item {
    text-align: center;
    padding: 30px 20px;
    background: var(--bg-light);
    border-radius: var(--radius);
}

.value-icon {
    font-size: 40px;
    display: block;
    margin-bottom: 16px;
}

.value-item h3 {
    font-size: 18px;
    margin-bottom: 8px;
}

.value-item p {
    color: var(--text-secondary);
    font-size: 14px;
}

.contact {
    background: var(--bg-dark);
    color: white;
}

.contact h2 {
    color: white;
}

.contact-wrapper {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 60px;
    align-items: center;
}

.contact-info p {
    color: rgba(255,255,255,0.8);
    margin-bottom: 24px;
}

.contact-list {
    list-style: none;
    margin-bottom: 24px;
}

.contact-list li {
    padding: 10px 0;
    color: rgba(255,255,255,0.9);
}

.contact-note {
    font-size: 14px;
    padding: 16px;
    background: rgba(239, 68, 68, 0.2);
    border-radius: var(--radius);
    color: rgba(255,255,255,0.9);
}

.contact-cta {
    text-align: center;
}

.contact-cta img {
    border-radius: var(--radius-lg);
    margin-bottom: 30px;
}

.cta-subtitle {
    margin-top: 12px;
    color: rgba(255,255,255,0.7);
    font-size: 14px;
}

.footer {
    background: #0A1628;
    color: rgba(255,255,255,0.8);
    padding: 60px 0 30px;
}

.footer-main {
    display: grid;
    grid-template-columns: 300px 1fr;
    gap: 60px;
    padding-bottom: 40px;
    border-bottom: 1px solid rgba(255,255,255,0.1);
    margin-bottom: 30px;
}

.footer-logo {
    display: flex;
    align-items: center;
    gap: 10px;
    color: white;
    font-size: 20px;
    font-weight: 700;
    margin-bottom: 16px;
}

.footer-logo:hover {
    color: white;
}

.footer-brand p {
    font-size: 14px;
    color: rgba(255,255,255,0.6);
}

.footer-nav {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 40px;
}

.footer-nav h4 {
    color: white;
    font-size: 16px;
    margin-bottom: 20px;
}

.footer-nav ul {
    list-style: none;
}

.footer-nav li {
    margin-bottom: 12px;
}

.footer-nav a {
    color: rgba(255,255,255,0.6);
    font-size: 14px;
}

.footer-nav a:hover {
    color: white;
}

.footer-bottom {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    flex-wrap: wrap;
    gap: 20px;
}

.footer-links {
    display: flex;
    gap: 24px;
}

.footer-links a {
    color: rgba(255,255,255,0.5);
    font-size: 13px;
}

.footer-links a:hover {
    color: white;
}

.footer-info {
    text-align: right;
    font-size: 13px;
}

.footer-info p {
    margin-bottom: 8px;
}

.footer-info a {
    color: rgba(255,255,255,0.6);
}

.footer-info a:hover {
    color: white;
}

.copyright {
    color: rgba(255,255,255,0.4);
}

.icp a {
    color: rgba(255,255,255,0.4);
}

.update-time {
    color: rgba(255,255,255,0.3);
    font-size: 12px;
}

.back-to-top {
    position: fixed;
    bottom: 60px;
    right: 30px;
    width: 50px;
    height: 50px;
    background: var(--gradient);
    color: white;
    border: none;
    border-radius: 50%;
    cursor: pointer;
    opacity: 0;
    visibility: hidden;
    transition: var(--transition);
    box-shadow: var(--shadow-md);
    z-index: 999;
}

.back-to-top.visible {
    opacity: 1;
    visibility: visible;
}

.back-to-top:hover {
    transform: translateY(-3px);
    box-shadow: var(--shadow-lg);
}

.back-to-top svg {
    width: 24px;
    height: 24px;
}

@media (max-width: 1024px) {
    .download-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .features-showcase {
        grid-template-columns: 1fr;
    }
    
    .feature-main {
        order: 2;
    }
    
    .tutorial-grid {
        grid-template-columns: 1fr;
        gap: 40px;
    }
    
    .tutorial-visual {
        max-width: 280px;
        margin: 0 auto;
    }
    
    .security-hero {
        grid-template-columns: 1fr;
    }
    
    .security-hero img {
        max-width: 400px;
        margin: 0 auto;
    }
    
    .topic-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .about-content {
        grid-template-columns: 1fr;
    }
    
    .about-image {
        order: -1;
        text-align: center;
    }
    
    .about-image img {
        max-width: 350px;
    }
    
    .brand-values {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (max-width: 768px) {
    .mobile-menu-btn {
        display: flex;
    }
    
    .main-nav {
        position: fixed;
        top: 70px;
        left: 0;
        right: 0;
        background: white;
        padding: 20px;
        box-shadow: var(--shadow-lg);
        transform: translateY(-100%);
        opacity: 0;
        visibility: hidden;
        transition: var(--transition);
    }
    
    .main-nav.active {
        transform: translateY(0);
        opacity: 1;
        visibility: visible;
    }
    
    .nav-list {
        flex-direction: column;
        gap: 0;
    }
    
    .nav-list a {
        display: block;
        padding: 14px 20px;
        border-bottom: 1px solid var(--border-light);
    }
    
    .hero h1 {
        font-size: 32px;
    }
    
    .hero-subtitle {
        font-size: 16px;
    }
    
    .hero-stats {
        gap: 30px;
    }
    
    .stat-num {
        font-size: 28px;
    }
    
    section {
        padding: 60px 0;
    }
    
    section h2 {
        font-size: 28px;
    }
    
    .download-grid {
        grid-template-columns: 1fr;
    }
    
    .tutorial-visual {
        max-width: 220px;
    }
    
    .phone-screen {
        border-radius: 12px;
    }
    
    .screenshot-dots {
        margin-top: 16px;
    }
    
    .screenshot-dots .dot {
        width: 8px;
        height: 8px;
    }
    
    .screenshot-dots .dot.active {
        width: 24px;
    }
    
    .tutorial-steps {
        gap: 16px;
    }
    
    .step-card {
        padding: 20px;
        gap: 16px;
    }
    
    .step-number {
        font-size: 24px;
    }
    
    .alert-grid {
        grid-template-columns: 1fr;
    }
    
    .news-grid {
        grid-template-columns: 1fr;
    }
    
    .contact-wrapper {
        grid-template-columns: 1fr;
    }
    
    .footer-main {
        grid-template-columns: 1fr;
        gap: 40px;
    }
    
    .footer-nav {
        grid-template-columns: 1fr;
        gap: 30px;
    }
    
    .footer-bottom {
        flex-direction: column;
        align-items: flex-start;
    }
    
    .footer-info {
        text-align: left;
    }
    
    .verify-methods {
        flex-direction: column;
        align-items: center;
        gap: 16px;
    }
    
    .topic-grid {
        grid-template-columns: 1fr;
    }
    
    .brand-values {
        grid-template-columns: 1fr;
    }
    
    .back-to-top {
        bottom: 110px;
        right: 20px;
    }
}

@media (max-width: 480px) {
    .hero h1 {
        font-size: 26px;
    }
    
    .hero-buttons {
        flex-direction: column;
    }
    
    .hero-buttons .btn {
        width: 100%;
    }
    
    .btn-lg {
        padding: 14px 28px;
        font-size: 15px;
    }
}