/* 全局样式重置 */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

/* 基础样式 */
body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    line-height: 1.6;
    color: #2c3e50;
    overflow-x: hidden;
    background-color: #f8f9fa;
}

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

/* 按钮样式 */
.btn {
    display: inline-block;
    padding: 14px 28px;
    border-radius: 8px;
    text-decoration: none;
    font-size: 16px;
    font-weight: 600;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    border: none;
    cursor: pointer;
    position: relative;
    overflow: hidden;
}

.btn-primary {
    background: linear-gradient(135deg, #1890ff 0%, #096dd9 100%);
    color: #fff;
    box-shadow: 0 4px 15px rgba(24, 144, 255, 0.3);
}

.btn-primary:hover {
    background: linear-gradient(135deg, #096dd9 0%, #1890ff 100%);
    transform: translateY(-3px);
    box-shadow: 0 8px 25px rgba(24, 144, 255, 0.4);
}

.btn-outline {
    background-color: transparent;
    color: #1890ff;
    border: 2px solid #1890ff;
}

.btn-outline:hover {
    background: linear-gradient(135deg, #1890ff 0%, #096dd9 100%);
    color: #fff;
    box-shadow: 0 4px 15px rgba(24, 144, 255, 0.3);
}

.btn-download {
    background: linear-gradient(135deg, #52c41a 0%, #389e0d 100%);
    color: #fff;
    box-shadow: 0 4px 15px rgba(82, 196, 26, 0.3);
}

.btn-download:hover {
    background: linear-gradient(135deg, #389e0d 0%, #52c41a 100%);
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(82, 196, 26, 0.4);
}

.btn-large {
    padding: 18px 36px;
    font-size: 18px;
}

/* 头部导航 */
.header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    background-color: rgba(255, 255, 255, 0.98);
    backdrop-filter: blur(20px);
    z-index: 1000;
    box-shadow: 0 2px 30px rgba(0, 0, 0, 0.05);
    transition: all 0.3s ease;
}

.header-content {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 15px 0;
}

.logo {
    text-decoration: none;
    display: flex;
    align-items: center;
}

.logo-text {
    font-size: 28px;
    font-weight: 700;
    color: #1890ff;
    background: linear-gradient(135deg, #1890ff, #096dd9);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

/* 桌面端导航 */
.nav-desktop {
    display: block;
}

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

.nav-link {
    text-decoration: none;
    color: #546e7a;
    font-weight: 500;
    transition: all 0.3s ease;
    position: relative;
    padding: 8px 0;
    letter-spacing: 0.2px;
}

.nav-link:hover {
    color: #1890ff;
}

.nav-link::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 0;
    height: 3px;
    background: linear-gradient(90deg, #1890ff, #096dd9);
    border-radius: 3px;
    transition: width 0.3s ease;
}

.nav-link:hover::after {
    width: 100%;
}

/* 移动端菜单按钮 */
.mobile-menu-btn {
    display: none;
    background: none;
    border: none;
    cursor: pointer;
    padding: 10px;
    position: relative;
    z-index: 1100;
    width: 40px;
    height: 40px;
}

.mobile-menu-btn span {
    display: block;
    width: 24px;
    height: 3px;
    background-color: #2c3e50;
    margin: 5px auto;
    transition: all 0.3s ease;
    border-radius: 3px;
}

.mobile-menu-btn.active .menu-icon {
    opacity: 0;
    transform: rotate(45deg);
}

.mobile-menu-btn.active .close-icon {
    opacity: 1;
    transform: rotate(90deg);
}

.close-icon {
    opacity: 0;
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%) rotate(0deg);
}

.close-icon::before {
    content: '';
    position: absolute;
    width: 24px;
    height: 3px;
    background-color: #2c3e50;
    transform: rotate(45deg);
    border-radius: 3px;
}

.close-icon::after {
    content: '';
    position: absolute;
    width: 24px;
    height: 3px;
    background-color: #2c3e50;
    transform: rotate(-45deg);
    border-radius: 3px;
}

/* 移动端导航遮罩层 */
.mobile-nav-overlay {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background-color: rgba(0, 0, 0, 0.5);
    z-index: 990;
    backdrop-filter: blur(5px);
}

.mobile-nav-overlay.active {
    display: block;
}

/* 移动端导航菜单 */
.nav-mobile {
    position: fixed;
    top: 0;
    right: -100%;
    width: 80%;
    max-width: 300px;
    height: 100vh;
    background-color: rgba(255, 255, 255, 0.98);
    backdrop-filter: blur(20px);
    z-index: 1050;
    transition: right 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    padding: 80px 20px 20px;
    box-shadow: -5px 0 30px rgba(0, 0, 0, 0.1);
}

.nav-mobile.active {
    right: 0;
}

.nav-mobile-list {
    list-style: none;
}

.nav-mobile-item {
    margin-bottom: 25px;
}

.nav-mobile-link {
    display: block;
    text-decoration: none;
    color: #2c3e50;
    font-size: 18px;
    font-weight: 500;
    padding: 12px 16px;
    border-radius: 8px;
    transition: all 0.3s ease;
    background-color: rgba(24, 144, 255, 0.05);
}

.nav-mobile-link:hover {
    background-color: rgba(24, 144, 255, 0.1);
    color: #1890ff;
    transform: translateX(5px);
}

/* 英雄区域 */
.hero {
    background: linear-gradient(135deg, #0f2027 0%, #203a43 50%, #2c5364 100%);
    color: #fff;
    padding: 180px 0 120px;
    text-align: center;
    position: relative;
    overflow: hidden;
}

.hero::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: 
        radial-gradient(circle at 20% 50%, rgba(24, 144, 255, 0.3) 0%, transparent 50%),
        radial-gradient(circle at 80% 20%, rgba(82, 196, 26, 0.2) 0%, transparent 50%),
        radial-gradient(circle at 40% 80%, rgba(255, 193, 7, 0.2) 0%, transparent 50%);
    animation: gradient-shift 15s ease infinite;
}

@keyframes gradient-shift {
    0%, 100% { transform: rotate(0deg) scale(1); }
    50% { transform: rotate(180deg) scale(1.1); }
}

.hero-content {
    max-width: 850px;
    margin: 0 auto;
    position: relative;
    z-index: 2;
}

.hero-title {
    font-size: 52px;
    font-weight: 800;
    margin-bottom: 25px;
    line-height: 1.1;
    background: linear-gradient(135deg, #ffffff, #a7c5eb);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    text-shadow: 0 4px 20px rgba(0, 0, 0, 0.1);
    letter-spacing: -0.5px;
}

.hero-subtitle {
    font-size: 22px;
    margin-bottom: 50px;
    opacity: 0.95;
    font-weight: 400;
    letter-spacing: 0.5px;
    color: rgba(255, 255, 255, 0.9);
}

.hero-features {
    display: flex;
    gap: 20px;
    justify-content: center;
    flex-wrap: wrap;
    margin-top: 40px;
}

.feature-tag {
    background-color: rgba(255, 255, 255, 0.15);
    padding: 8px 16px;
    border-radius: 20px;
    font-size: 14px;
    backdrop-filter: blur(10px);
    border: 1px solid rgba(255, 255, 255, 0.2);
}

/* 主要下载区域 */
.main-download {
    padding: 100px 0;
    background-color: #fff;
    position: relative;
    overflow: hidden;
}

.download-cards {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
    gap: 30px;
    margin-top: 60px;
}

.download-card {
    background: linear-gradient(135deg, #ffffff, #f5f7fa);
    border-radius: 16px;
    padding: 40px 30px;
    box-shadow: 0 8px 35px rgba(0, 0, 0, 0.03);
    transition: all 0.4s cubic-bezier(0.4, 0, 0.2, 1);
    border: 1px solid rgba(24, 144, 255, 0.1);
    position: relative;
    overflow: hidden;
}

.download-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 4px;
    background: linear-gradient(90deg, #1890ff, #52c41a);
    transform: scaleX(0);
    transition: transform 0.3s ease;
}

.download-card:hover {
    transform: translateY(-10px);
    box-shadow: 0 20px 50px rgba(24, 144, 255, 0.12);
    border-color: rgba(24, 144, 255, 0.3);
}

.download-card:hover::before {
    transform: scaleX(1);
}

.download-title {
    font-size: 24px;
    font-weight: 600;
    margin-bottom: 15px;
    color: #2c3e50;
}

.download-description {
    font-size: 16px;
    color: #607d8b;
    margin-bottom: 20px;
    line-height: 1.6;
}

.download-info {
    display: flex;
    gap: 20px;
    margin-bottom: 30px;
    font-size: 14px;
    color: #90a4ae;
}

/* 通用区域样式 */
.features, .templates, .pdf-tools {
    padding: 100px 0;
    position: relative;
    overflow: hidden;
}

.features, .templates {
    background-color: #fff;
}

.pdf-tools {
    background-color: #f8f9fa;
}

.section-header {
    text-align: center;
    margin-bottom: 60px;
}

.section-title {
    font-size: 36px;
    font-weight: 700;
    margin-bottom: 20px;
    color: #2c3e50;
    background: linear-gradient(135deg, #2c3e50, #34495e);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    letter-spacing: -0.5px;
}

.section-subtitle {
    font-size: 18px;
    color: #607d8b;
    max-width: 600px;
    margin: 0 auto;
    line-height: 1.6;
}

/* 功能特点 */
.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 30px;
    margin-top: 60px;
}

.feature-card {
    background: linear-gradient(135deg, #ffffff, #f5f7fa);
    border-radius: 12px;
    padding: 30px;
    box-shadow: 0 5px 25px rgba(0, 0, 0, 0.08);
    transition: all 0.3s ease;
    border: 1px solid rgba(24, 144, 255, 0.1);
    text-align: center;
}

.feature-card:hover {
    transform: translateY(-10px);
    box-shadow: 0 15px 35px rgba(24, 144, 255, 0.15);
    border-color: rgba(24, 144, 255, 0.3);
}

.feature-icon {
    width: 80px;
    height: 80px;
    background: linear-gradient(135deg, #1890ff, #096dd9);
    border-radius: 20px;
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto 25px;
    box-shadow: 0 5px 20px rgba(24, 144, 255, 0.3);
}

/* 功能图标样式 */
.icon-writer::before,
.icon-spreadsheet::before,
.icon-presentation::before,
.icon-pdf::before {
    font-size: 40px;
    color: #fff;
    font-weight: bold;
}

.icon-writer::before {
    content: '📝';
}

.icon-spreadsheet::before {
    content: '📊';
}

.icon-presentation::before {
    content: '🎬';
}

.icon-pdf::before {
    content: '📄';
}

.feature-title {
    font-size: 22px;
    font-weight: 600;
    margin-bottom: 15px;
    color: #2c3e50;
}

.feature-description {
    color: #607d8b;
    line-height: 1.6;
}

/* 模板介绍 */
.templates-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 30px;
    margin-top: 60px;
}

.template-card {
    background: linear-gradient(135deg, #ffffff, #f5f7fa);
    border-radius: 12px;
    padding: 40px 30px;
    box-shadow: 0 5px 25px rgba(0, 0, 0, 0.08);
    transition: all 0.3s ease;
    border: 1px solid rgba(82, 196, 26, 0.1);
    text-align: center;
}

.template-card:hover {
    transform: translateY(-10px);
    box-shadow: 0 15px 35px rgba(82, 196, 26, 0.15);
    border-color: rgba(82, 196, 26, 0.3);
}

.template-image {
    width: 120px;
    height: 120px;
    background: linear-gradient(135deg, #52c41a, #389e0d);
    border-radius: 20px;
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto 25px;
    box-shadow: 0 5px 20px rgba(82, 196, 26, 0.3);
}

/* 模板图标样式 */
.template-icon::before {
    font-size: 60px;
    color: #fff;
    font-weight: bold;
    content: '📋';
}

.template-title {
    font-size: 22px;
    font-weight: 600;
    margin-bottom: 15px;
    color: #2c3e50;
}

.template-description {
    color: #607d8b;
    line-height: 1.6;
}

/* PDF 工具包 */
.pdf-tools-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
    gap: 30px;
    margin-top: 60px;
}

.pdf-tool-card {
    background: linear-gradient(135deg, #ffffff, #f5f7fa);
    border-radius: 12px;
    padding: 40px 30px;
    box-shadow: 0 5px 25px rgba(0, 0, 0, 0.08);
    transition: all 0.3s ease;
    border: 1px solid rgba(255, 152, 0, 0.1);
}

.pdf-tool-card:hover {
    transform: translateY(-10px);
    box-shadow: 0 15px 35px rgba(255, 152, 0, 0.15);
    border-color: rgba(255, 152, 0, 0.3);
}

.tool-title {
    font-size: 22px;
    font-weight: 600;
    margin-bottom: 15px;
    color: #2c3e50;
}

.tool-description {
    color: #607d8b;
    margin-bottom: 25px;
    line-height: 1.6;
}

/* 下载提醒 */
.download-cta {
    padding: 100px 0;
    background: linear-gradient(135deg, #0f2027 0%, #203a43 50%, #2c5364 100%);
    color: #fff;
    text-align: center;
    position: relative;
    overflow: hidden;
}

.download-cta::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: 
        radial-gradient(circle at 30% 60%, rgba(24, 144, 255, 0.3) 0%, transparent 50%),
        radial-gradient(circle at 70% 40%, rgba(82, 196, 26, 0.2) 0%, transparent 50%);
}

.cta-content {
    max-width: 700px;
    margin: 0 auto;
    position: relative;
    z-index: 2;
}

.cta-title {
    font-size: 42px;
    font-weight: 700;
    margin-bottom: 20px;
    background: linear-gradient(135deg, #ffffff, #a7c5eb);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.cta-subtitle {
    font-size: 18px;
    margin-bottom: 40px;
    opacity: 0.9;
    line-height: 1.6;
}

/* 页脚 */
.footer {
    padding: 80px 0 40px;
    background-color: #2c3e50;
    color: #fff;
}

.footer-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 40px;
    margin-bottom: 60px;
}

.footer-heading {
    font-size: 20px;
    font-weight: 600;
    margin-bottom: 20px;
    color: #fff;
}

.footer-description {
    color: rgba(255, 255, 255, 0.7);
    line-height: 1.6;
}

.footer-links {
    list-style: none;
}

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

.footer-link {
    color: rgba(255, 255, 255, 0.7);
    text-decoration: none;
    transition: all 0.3s ease;
    display: inline-block;
}

.footer-link:hover {
    color: #1890ff;
    transform: translateX(5px);
}

.footer-bottom {
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    padding-top: 40px;
    text-align: center;
    color: rgba(255, 255, 255, 0.5);
}

/* 响应式设计 */
@media (max-width: 1024px) {
    .nav-list {
        gap: 25px;
    }
    
    .hero-title {
        font-size: 42px;
    }
    
    .section-title {
        font-size: 32px;
    }
}

@media (max-width: 768px) {
    /* 头部导航 */
    .nav-desktop {
        display: none;
    }
    
    .mobile-menu-btn {
        display: block;
    }
    
    /* 英雄区域 */
    .hero {
        padding: 150px 0 100px;
    }
    
    .hero-title {
        font-size: 36px;
    }
    
    .hero-subtitle {
        font-size: 18px;
    }
    
    .hero-features {
        flex-direction: column;
        align-items: center;
    }
    
    /* 通用区域 */
    .main-download, .features, .templates, .pdf-tools, .download-cta {
        padding: 80px 0;
    }
    
    /* 下载卡片 */
    .download-cards {
        grid-template-columns: 1fr;
        gap: 25px;
    }
    
    /* 功能特点 */
    .features-grid {
        grid-template-columns: repeat(2, 1fr);
        gap: 20px;
    }
    
    /* 模板和工具 */
    .templates-grid, .pdf-tools-grid {
        grid-template-columns: 1fr;
        gap: 25px;
    }
    
    /* 页脚 */
    .footer-content {
        grid-template-columns: 1fr;
        gap: 30px;
    }
}

@media (max-width: 480px) {
    /* 英雄区域 */
    .hero {
        padding: 120px 0 80px;
    }
    
    .hero-title {
        font-size: 28px;
    }
    
    .hero-subtitle {
        font-size: 16px;
    }
    
    /* 按钮 */
    .btn-large {
        padding: 14px 28px;
        font-size: 16px;
    }
    
    /* 通用区域 */
    .main-download, .features, .templates, .pdf-tools, .download-cta {
        padding: 60px 0;
    }
    
    /* 功能特点 */
    .features-grid {
        grid-template-columns: 1fr;
    }
    
    /* 卡片样式 */
    .download-card, .feature-card, .template-card, .pdf-tool-card {
        padding: 25px 20px;
    }
    
    /* 标题 */
    .section-title {
        font-size: 28px;
    }
    
    .cta-title {
        font-size: 32px;
    }
}