:root {
    --primary-color: #000000;
    --secondary-color: #00A980;
    --accent-color: #FF6B4A;
    --text-color: #333333;
    --light-text: #FFFFFF;
    --background: #FFFFFF;
    --section-bg: #F5F9FC;
    --card-shadow: 0 10px 20px rgba(0, 0, 0, 0.08);
    --transition: all 0.3s ease;
    --header-height: 70px;
    --mobile-header-height: 60px;
}

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

body {
    font-family: 'PingFang SC', 'Microsoft YaHei', sans-serif;
    color: var(--text-color);
    line-height: 1.6;
}

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

/* 导航样式优化 */
.main-nav {
    background: #000000;
    position: fixed;
    width: 100%;
    top: 0;
    z-index: 1000;
    box-shadow: 0 2px 10px rgba(0,0,0,0.1);
}

.main-nav .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 80px;
}

.logo a {
    color: var(--light-text);
    text-decoration: none;
    font-size: 26px;
    font-weight: bold;
}

.nav-menu {
    display: flex;
    list-style: none;
    gap: 35px;
}

.nav-menu a {
    color: var(--light-text);
    text-decoration: none;
    font-size: 16px;
    font-weight: 500;
    transition: var(--transition);
    padding: 8px 12px;
    border-radius: 4px;
}

.nav-menu a:hover {
    background: var(--secondary-color);
    color: var(--light-text);
}

/* Banner区域样式 */
.intro-banner {
    padding: 120px 0 80px;
    background: #000000;
    color: var(--light-text);
    position: relative;
    overflow: hidden;
}

.banner-content {
    max-width: 1200px;
    position: relative;
    z-index: 2;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 40px;
}

.banner-text {
    flex: 1;
    max-width: 600px;
}

.banner-image {
    flex: 1;
    display: flex;
    justify-content: center;
    align-items: center;
}

.banner-featured-image {
    max-width: 100%;
    height: auto;
    max-height: 500px;
    border-radius: 12px;
    box-shadow: 0 8px 24px rgba(0,0,0,0.2);
    -webkit-user-select: none;
    -moz-user-select: none;
    -ms-user-select: none;
    user-select: none;
    -webkit-touch-callout: none;
    pointer-events: none;
}

.banner-content h1 {
    font-size: 48px;
    margin-bottom: 25px;
    line-height: 1.2;
}

.intro-text {
    font-size: 18px;
    margin-bottom: 35px;
    opacity: 0.9;
}

.action-btns {
    display: flex;
    gap: 20px;
}

.btn-primary, .btn-outline {
    padding: 15px 35px;
    border-radius: 8px;
    text-decoration: none;
    font-weight: 500;
    transition: var(--transition);
    display: inline-flex;
    align-items: center;
    justify-content: center;
}

.btn-primary {
    background: var(--accent-color);
    color: var(--light-text);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 5px 15px rgba(255, 107, 74, 0.3);
}

.btn-outline {
    border: 2px solid var(--light-text);
    color: var(--light-text);
}

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

/* 下载区域样式 */
.download-section {
    padding: 60px 0;
    background: var(--section-bg);
}

.download-image {
    text-align: center;
    margin-bottom: 30px;
}

.download-featured-image {
    max-width: 100%;
    height: auto;
    max-height: 400px;
    border-radius: 8px;
    box-shadow: 0 4px 12px rgba(0,0,0,0.15);
}

@media (max-width: 768px) {
    .download-featured-image {
        max-height: 250px;
    }
}

.download-section h2 {
    text-align: center;
    font-size: 36px;
    margin-bottom: 50px;
    color: var(--primary-color);
}

.download-options {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 30px;
}

.download-card {
    background: var(--background);
    padding: 40px;
    border-radius: 16px;
    box-shadow: var(--card-shadow);
    transition: var(--transition);
}

.download-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 15px 30px rgba(0, 0, 0, 0.12);
}

.download-card h3 {
    color: var(--primary-color);
    font-size: 24px;
    margin-bottom: 20px;
}

.feature-list {
    list-style: none;
    margin: 25px 0;
}

.feature-list li {
    margin: 12px 0;
    padding-left: 25px;
    position: relative;
}

.feature-list li::before {
    content: "✓";
    color: var(--secondary-color);
    position: absolute;
    left: 0;
    font-weight: bold;
}

.download-btn {
    display: inline-block;
    padding: 14px 32px;
    background: var(--secondary-color);
    color: var(--light-text);
    text-decoration: none;
    border-radius: 8px;
    transition: var(--transition);
    text-align: center;
    width: 100%;
}

.download-btn:hover {
    background: #008c69;
    transform: translateY(-2px);
}

/* 特色功能区域 */
.features-section {
    padding: 60px 0;
    background: var(--section-bg);
}

.section-header {
    text-align: center;
    margin-bottom: 40px;
}

.section-header h2 {
    font-size: 36px;
    color: var(--primary-color);
    margin-bottom: 15px;
}

.section-desc {
    font-size: 18px;
    color: #666;
    max-width: 700px;
    margin: 0 auto;
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 30px;
    margin-top: 50px;
}

.feature-card {
    background: var(--background);
    border-radius: 20px;
    padding: 40px;
    box-shadow: var(--card-shadow);
    transition: var(--transition);
    display: flex;
    gap: 25px;
    position: relative;
    overflow: hidden;
}

.feature-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 4px;
    height: 100%;
    background: var(--secondary-color);
    transition: var(--transition);
}

.feature-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 15px 30px rgba(0, 0, 0, 0.12);
}

.feature-card:hover::before {
    width: 100%;
    opacity: 0.1;
}

.feature-icon {
    flex-shrink: 0;
    width: 60px;
    height: 60px;
    background: var(--section-bg);
    border-radius: 15px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 28px;
    color: var(--secondary-color);
}

.feature-content {
    flex: 1;
}

.feature-content h3 {
    font-size: 22px;
    color: var(--primary-color);
    margin-bottom: 15px;
}

.feature-content p {
    color: #666;
    margin-bottom: 20px;
    line-height: 1.6;
}

.feature-details {
    list-style: none;
    padding: 0;
    margin: 0;
}

.feature-details li {
    position: relative;
    padding-left: 20px;
    margin-bottom: 10px;
    color: #666;
    font-size: 15px;
}

.feature-details li::before {
    content: "•";
    color: var(--secondary-color);
    position: absolute;
    left: 0;
    font-weight: bold;
}

@media (max-width: 992px) {
    .features-grid {
        grid-template-columns: 1fr;
    }
    
    .feature-card {
        padding: 30px;
    }
}

@media (max-width: 768px) {
    .section-header h2 {
        font-size: 28px;
    }
    
    .section-desc {
        font-size: 16px;
    }
    
    .feature-card {
        flex-direction: column;
        text-align: center;
        padding: 25px;
    }
    
    .feature-icon {
        margin: 0 auto 20px;
    }
    
    .feature-details li {
        text-align: left;
    }
}

/* 安装教程区域 */
.guide-section {
    padding: 60px 0;
    background: var(--section-bg);
}

.guide-container {
    max-width: 1000px;
    margin: 0 auto;
}

.guide-steps {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 25px;
    margin-bottom: 30px;
}

.guide-step {
    background: var(--background);
    border-radius: 20px;
    padding: 40px 30px;
    position: relative;
    box-shadow: var(--card-shadow);
    transition: var(--transition);
}

.guide-step:hover {
    transform: translateY(-5px);
    box-shadow: 0 15px 30px rgba(0, 0, 0, 0.12);
}

.step-number {
    position: absolute;
    top: 20px;
    right: 20px;
    font-size: 48px;
    font-weight: bold;
    color: var(--secondary-color);
    opacity: 0.1;
}

.step-icon {
    width: 60px;
    height: 60px;
    background: var(--section-bg);
    border-radius: 15px;
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: 20px;
    color: var(--secondary-color);
    font-size: 28px;
}

.step-content h3 {
    font-size: 22px;
    color: var(--primary-color);
    margin-bottom: 15px;
}

.step-content p {
    color: #666;
    margin-bottom: 20px;
    line-height: 1.6;
}

.step-details {
    list-style: none;
    padding: 0;
    margin: 0;
}

.step-details li {
    position: relative;
    padding-left: 20px;
    margin-bottom: 10px;
    color: #666;
    font-size: 15px;
}

.step-details li::before {
    content: "→";
    color: var(--secondary-color);
    position: absolute;
    left: 0;
    font-weight: bold;
}

.guide-note {
    background: var(--primary-color);
    border-radius: 20px;
    padding: 30px;
    color: var(--light-text);
}

.note-content h4 {
    font-size: 20px;
    margin-bottom: 15px;
    color: var(--light-text);
}

.note-content ul {
    list-style: none;
    padding: 0;
    margin: 0;
}

.note-content ul li {
    position: relative;
    padding-left: 25px;
    margin-bottom: 10px;
    color: rgba(255, 255, 255, 0.9);
    font-size: 15px;
}

.note-content ul li::before {
    content: "!";
    color: var(--accent-color);
    position: absolute;
    left: 0;
    font-weight: bold;
}

@media (max-width: 992px) {
    .guide-steps {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (max-width: 768px) {
    .guide-steps {
        grid-template-columns: 1fr;
    }
    
    .guide-step {
        padding: 30px 20px;
    }
    
    .step-number {
        font-size: 36px;
    }
    
    .step-icon {
        width: 50px;
        height: 50px;
        font-size: 24px;
    }
    
    .step-content h3 {
        font-size: 20px;
    }
}

/* 安全保障区域 */
.safe-section {
    padding: 60px 0;
    background: var(--section-bg);
}

.safe-container {
    max-width: 1200px;
    margin: 0 auto;
}

.safe-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 25px;
    margin-bottom: 30px;
}

.safe-card {
    background: var(--background);
    border-radius: 20px;
    padding: 40px;
    box-shadow: var(--card-shadow);
    transition: var(--transition);
    display: flex;
    gap: 25px;
    position: relative;
    overflow: hidden;
}

.safe-card::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 100%;
    height: 3px;
    background: var(--secondary-color);
    transform: scaleX(0);
    transition: transform 0.3s ease;
}

.safe-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 15px 30px rgba(0, 0, 0, 0.12);
}

.safe-card:hover::after {
    transform: scaleX(1);
}

.safe-icon {
    flex-shrink: 0;
    width: 60px;
    height: 60px;
    background: var(--section-bg);
    border-radius: 15px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 28px;
    color: var(--secondary-color);
}

.safe-content {
    flex: 1;
}

.safe-content h3 {
    font-size: 22px;
    color: var(--primary-color);
    margin-bottom: 15px;
}

.safe-content p {
    color: #666;
    margin-bottom: 20px;
    line-height: 1.6;
}

.safe-details {
    list-style: none;
    padding: 0;
    margin: 0;
}

.safe-details li {
    position: relative;
    padding-left: 20px;
    margin-bottom: 10px;
    color: #666;
    font-size: 15px;
}

.safe-details li::before {
    content: "✓";
    color: var(--secondary-color);
    position: absolute;
    left: 0;
    font-weight: bold;
}

.safe-stats {
    display: flex;
    justify-content: space-around;
    background: var(--primary-color);
    border-radius: 20px;
    padding: 30px;
    margin-top: 20px;
}

.stat-item {
    text-align: center;
    color: var(--light-text);
}

.stat-number {
    font-size: 36px;
    font-weight: bold;
    margin-bottom: 10px;
    color: var(--accent-color);
}

.stat-label {
    font-size: 16px;
    opacity: 0.9;
}

@media (max-width: 992px) {
    .safe-grid {
        grid-template-columns: 1fr;
    }
    
    .safe-stats {
        flex-direction: column;
        gap: 30px;
        padding: 30px;
    }
}

@media (max-width: 768px) {
    .safe-card {
        padding: 30px 20px;
        flex-direction: column;
        text-align: center;
    }
    
    .safe-icon {
        margin: 0 auto 20px;
    }
    
    .safe-details li {
        text-align: left;
    }
    
    .stat-number {
        font-size: 28px;
    }
    
    .stat-label {
        font-size: 14px;
    }
}

/* 页脚样式 */
.site-footer {
    background: var(--darker-bg);
    padding: 15px 0;
    text-align: center;
}

.footer-content {
    color: var(--text-color);
    font-size: 13px;
}

.site-footer p {
    text-align: center;
    margin: 5px 0;
    color: var(--text-color);
    font-size: 13px;
}

.site-footer a {
    color: var(--text-color);
    text-decoration: none;
    transition: var(--transition);
}

.site-footer a:hover {
    color: var(--primary-color);
}

/* 响应式设计 */
@media (max-width: 768px) {
    .nav-toggle {
        display: block;
        width: 30px;
        height: 22px;
        position: relative;
        cursor: pointer;
    }

    .nav-toggle span {
        display: block;
        width: 100%;
        height: 2px;
        background: var(--light-text);
        position: absolute;
        transition: var(--transition);
    }

    .nav-toggle span:first-child {
        top: 0;
    }

    .nav-toggle span:nth-child(2) {
        top: 10px;
    }

    .nav-toggle span:last-child {
        bottom: 0;
    }

    .nav-menu {
        display: none;
        position: absolute;
        top: 80px;
        left: 0;
        width: 100%;
        background: var(--primary-color);
        padding: 20px;
        flex-direction: column;
        gap: 15px;
    }

    .nav-menu.active {
        display: flex;
    }

    .banner-content h1 {
        font-size: 36px;
    }

    .action-btns {
        flex-direction: column;
    }

    .download-options,
    .features-grid,
    .guide-steps,
    .safe-grid {
        grid-template-columns: 1fr;
    }
}

/* 动画效果 */
@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.download-card,
.feature-item,
.guide-step,
.safe-card {
    animation: fadeInUp 0.6s ease-out forwards;
}

/* 广告区域样式 */
.ad-section {
    padding: 20px 0;
    background: var(--background);
}

.ad-section .container {
    text-align: center;
}

/* 友情链接和相关站点样式 */
.related-links {
    padding: 20px 0;
    background: var(--section-bg);
}

.friend-links {
    margin-bottom: 15px;
}

.related-sites ul {
    list-style: none;
    display: flex;
    flex-wrap: wrap;
    gap: 15px;
    justify-content: center;
}

.related-sites li a {
    color: var(--text-color);
    text-decoration: none;
    padding: 6px 12px;
    border-radius: 4px;
    background: var(--background);
    transition: var(--transition);
}

.related-sites li a:hover {
    color: var(--secondary-color);
    box-shadow: var(--card-shadow);
}

/* 底部导航样式 */
.footer-nav {
    background: var(--dark-bg);
    padding: 30px 0;
    margin-top: 20px;
}

.footer-nav-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 20px;
}

.footer-nav-column h4 {
    color: var(--light-text);
    font-size: 16px;
    margin-bottom: 15px;
    font-weight: 600;
}

.footer-nav-column ul {
    list-style: none;
    padding: 0;
    margin: 0;
}

.footer-nav-column ul li {
    margin-bottom: 8px;
}

.footer-nav-column ul li a {
    color: var(--text-color);
    text-decoration: none;
    font-size: 13px;
    transition: var(--transition);
}

.footer-nav-column ul li a:hover {
    color: var(--primary-color);
}

/* 移动端适配 */
@media screen and (max-width: 768px) {
    .ad-section {
        padding: 15px 0;
    }

    .related-links {
        padding: 15px 0;
    }

    .related-sites ul {
        flex-direction: column;
        align-items: center;
        gap: 8px;
    }

    .footer-nav {
        padding: 20px 0;
        margin-top: 15px;
    }

    .footer-nav-grid {
        grid-template-columns: 1fr;
        gap: 15px;
    }

    .footer-nav-column {
        text-align: center;
    }

    .footer-nav-column h4 {
        font-size: 15px;
        margin-bottom: 10px;
    }

    .footer-nav-column ul li {
        margin-bottom: 6px;
    }

    .footer-nav-column ul li a {
        font-size: 12px;
    }

    .site-footer {
        padding: 12px 0;
    }
}

/* PC端导航样式（1200px以上） */
@media screen and (min-width: 1201px) {
    .container {
        max-width: 1200px;
        padding: 0 20px;
    }

    .nav-toggle {
        display: none;
    }

    .nav-menu {
        display: flex !important;
        gap: 30px;
    }
}

/* 平板端适配（768px - 1200px） */
@media screen and (max-width: 1200px) {
    .container {
        max-width: 100%;
        padding: 0 30px;
    }

    .banner-content h1 {
        font-size: 40px;
    }

    .features-grid,
    .download-options {
        grid-template-columns: repeat(2, 1fr);
    }
}

/* 移动端适配（768px以下） */
@media screen and (max-width: 768px) {
    .main-nav {
        height: 50px;
    }

    .main-nav .container {
        height: 50px;
        padding: 0 15px;
    }

    .logo a {
        font-size: 18px;
    }

    .nav-toggle {
        display: block;
        width: 22px;
        height: 16px;
        position: relative;
        cursor: pointer;
        margin-right: 5px;
    }

    .nav-toggle span {
        display: block;
        width: 100%;
        height: 1px;
        background: var(--light-text);
        position: absolute;
        transition: var(--transition);
    }

    .nav-toggle span:first-child {
        top: 0;
    }

    .nav-toggle span:nth-child(2) {
        top: 8px;
    }

    .nav-toggle span:last-child {
        bottom: 0;
    }

    .nav-menu {
        display: none;
        position: absolute;
        top: 50px;
        left: 0;
        width: 100%;
        background: rgba(0, 0, 0, 0.98);
        padding: 10px 0;
        flex-direction: column;
        gap: 0;
    }

    .nav-menu.active {
        display: flex;
    }

    .nav-menu li a {
        padding: 12px 20px;
        font-size: 15px;
        border-bottom: 1px solid rgba(255, 255, 255, 0.08);
        display: block;
    }

    .banner-content {
        flex-direction: column;
        text-align: center;
        gap: 30px;
    }

    .banner-text {
        max-width: 100%;
    }

    .banner-image {
        order: -1;
    }

    .banner-featured-image {
        max-height: 300px;
        -webkit-user-select: none;
        -moz-user-select: none;
        -ms-user-select: none;
        user-select: none;
        -webkit-touch-callout: none;
        pointer-events: none;
    }

    .banner-content h1 {
        font-size: 24px;
        margin-bottom: 15px;
    }

    .intro-text {
        font-size: 14px;
        margin-bottom: 25px;
    }

    .action-btns {
        flex-direction: column;
        gap: 15px;
    }

    .btn-primary, .btn-outline {
        padding: 10px 25px;
        font-size: 14px;
        width: 100%;
    }

    .download-section,
    .features-section,
    .guide-section,
    .safe-section {
        padding: 40px 0;
    }

    .section-header {
        margin-bottom: 30px;
    }

    .section-header h2 {
        font-size: 20px;
        margin-bottom: 10px;
    }

    .section-desc {
        font-size: 14px;
    }

    .download-options,
    .features-grid,
    .guide-steps,
    .safe-grid {
        grid-template-columns: 1fr;
        gap: 20px;
    }

    .download-card,
    .feature-card,
    .guide-step,
    .safe-card {
        padding: 20px;
    }

    .download-card h3,
    .feature-content h3,
    .step-content h3,
    .safe-content h3 {
        font-size: 18px;
    }

    .feature-list li,
    .feature-details li,
    .step-details li,
    .safe-details li {
        font-size: 14px;
        margin: 8px 0;
    }

    .download-btn {
        padding: 10px 20px;
        font-size: 14px;
    }

    .footer-nav {
        padding: 30px 0;
    }

    .footer-nav-grid {
        grid-template-columns: 1fr;
        gap: 20px;
    }

    .footer-nav-column {
        text-align: center;
    }

    .footer-nav-column h4 {
        font-size: 16px;
        margin-bottom: 15px;
    }

    .footer-nav-column ul li {
        margin-bottom: 8px;
    }

    .footer-nav-column ul li a {
        font-size: 13px;
    }
}