/* 重置样式 */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

/* 基础样式 */
body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
    line-height: 1.6;
    color: #333;
    background-color: #f5f7fa;
}

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

/* 标题样式 */
h2 {
    font-size: 2.5rem;
    text-align: center;
    margin-bottom: 2rem;
    color: #2c3e50;
    font-weight: 700;
}

/* 导航栏 */
.header-small {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    padding: 0;
    position: sticky;
    top: 0;
    z-index: 1000;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
}

/* 首页英雄区域 */
.hero-section {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    padding: 0 2rem;
    margin-top: -70px;
    padding-top: 100px;
    box-sizing: border-box;
}

.nav {
    display: flex;
    justify-content: space-between;
    align-items: center;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0.5rem 20px;
    position: relative;
    z-index: 1000;
    height: 70px;
    box-sizing: border-box;
}

.logo {
    font-size: 1.8rem;
    font-weight: 700;
    letter-spacing: 1px;
}

.nav-links {
    display: flex;
    list-style: none;
    gap: 2rem;
    margin: 0;
    padding: 0;
}

.nav-links li {
    margin: 0;
    padding: 0;
}

.nav-links a {
    color: white;
    text-decoration: none;
    font-weight: 500;
    transition: all 0.3s ease;
    position: relative;
    display: inline-block;
    padding: 0.5rem 0;
}

.nav-links a:hover {
    opacity: 0.8;
}

.nav-links a.active {
    font-weight: 700;
}

.nav-links a.active::after {
    content: '';
    position: absolute;
    bottom: -5px;
    left: 0;
    width: 100%;
    height: 2px;
    background: white;
    border-radius: 2px;
}

/* 响应式设计 */
@media (max-width: 768px) {
    .nav {
        flex-direction: column;
        gap: 1rem;
    }
    
    .nav-links {
        gap: 1rem;
        justify-content: center;
    }
}

/* 英雄区域 */
.hero {
    flex: 1;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    text-align: center;
    padding: 2rem;
    max-width: 800px;
    margin: 0 auto;
}

.hero h1 {
    font-size: 3.5rem;
    margin-bottom: 1rem;
    line-height: 1.2;
    font-weight: 700;
}

.hero p {
    font-size: 1.2rem;
    margin-bottom: 2rem;
    opacity: 0.9;
}

/* 按钮样式 */
.cta-buttons {
    display: flex;
    gap: 1rem;
    flex-wrap: wrap;
    justify-content: center;
}

.btn-primary, .btn-secondary {
    padding: 1rem 2rem;
    border: none;
    border-radius: 50px;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
    text-decoration: none;
    display: inline-block;
}

.btn-primary {
    background: white;
    color: #667eea;
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.1);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(0, 0, 0, 0.15);
}

.btn-secondary {
    background: transparent;
    color: white;
    border: 2px solid white;
}

.btn-secondary:hover {
    background: white;
    color: #667eea;
}

/* 功能特性部分 */
.features {
    padding: 4rem 2rem;
    background: white;
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 1.5rem;
    max-width: 1200px;
    margin: 0 auto;
}

.feature-card {
    background: #f8f9fa;
    padding: 1.5rem;
    border-radius: 15px;
    text-align: center;
    transition: all 0.3s ease;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.05);
}

.feature-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 25px rgba(0, 0, 0, 0.1);
}

.feature-icon {
    font-size: 3rem;
    margin-bottom: 1rem;
}

.feature-card h3 {
    font-size: 1.5rem;
    margin-bottom: 1rem;
    color: #2c3e50;
}

.feature-card p {
    color: #666;
    font-size: 1rem;
}

/* 用户群体部分 */
.user-groups {
    padding: 4rem 2rem;
    background: #f5f7fa;
}

.users-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 1.5rem;
    max-width: 1200px;
    margin: 0 auto;
}

.user-card {
    background: white;
    padding: 1.5rem;
    border-radius: 15px;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.05);
    transition: all 0.3s ease;
}

.user-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 25px rgba(0, 0, 0, 0.1);
}

.user-icon {
    font-size: 3rem;
    margin-bottom: 1rem;
    text-align: center;
}

.user-card h3 {
    font-size: 1.4rem;
    margin-bottom: 0.5rem;
    color: #2c3e50;
    text-align: center;
}

.user-card p {
    color: #666;
    margin-bottom: 1.5rem;
    font-size: 0.95rem;
    text-align: center;
}

.user-benefits {
    list-style: none;
    padding: 0;
}

.user-benefits li {
    padding: 0.5rem 0;
    color: #555;
    position: relative;
    padding-left: 1.5rem;
}

.user-benefits li::before {
    content: "✓";
    color: #667eea;
    font-weight: bold;
    position: absolute;
    left: 0;
}

/* 下载部分 */
.download {
    padding: 4rem 2rem;
    background: white;
    text-align: center;
}

.download p {
    font-size: 1.1rem;
    color: #666;
    margin-bottom: 2rem;
    max-width: 600px;
    margin-left: auto;
    margin-right: auto;
}

.download-buttons {
    display: flex;
    gap: 1.2rem;
    justify-content: center;
    flex-wrap: wrap;
    max-width: 900px;
    margin: 0 auto;
}

.btn-download {
    display: flex;
    align-items: center;
    gap: 0.8rem;
    padding: 1rem 1.5rem;
    background: #f8f9fa;
    border: 2px solid #e9ecef;
    border-radius: 15px;
    cursor: pointer;
    transition: all 0.3s ease;
    text-align: left;
    min-width: 200px;
}

.btn-download:hover {
    transform: translateY(-3px);
    box-shadow: 0 8px 20px rgba(0, 0, 0, 0.1);
    border-color: #667eea;
}

.download-icon {
    font-size: 2rem;
}

.download-text {
    display: flex;
    flex-direction: column;
}

.download-title {
    font-weight: 700;
    color: #2c3e50;
    font-size: 1.1rem;
}

.download-subtitle {
    color: #666;
    font-size: 0.9rem;
}

/* 内容页面样式 */
.content-section {
    padding: 4rem 2rem;
    background: white;
}

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

.content-section h1 {
    font-size: 2.5rem;
    color: #2c3e50;
    margin-bottom: 2rem;
    text-align: center;
}

.content-section h3 {
    font-size: 1.5rem;
    color: #2c3e50;
    margin-top: 2rem;
    margin-bottom: 1rem;
}

.content-section p {
    font-size: 1rem;
    color: #555;
    line-height: 1.8;
    margin-bottom: 1rem;
}

.content-section ul {
    list-style: disc;
    padding-left: 2rem;
    margin-bottom: 1.5rem;
}

.content-section li {
    margin-bottom: 0.5rem;
    color: #555;
    line-height: 1.6;
}

/* 联系我们页面样式 */
.contact-info {
    margin: 2rem 0;
}

.contact-item {
    margin-bottom: 1rem;
    font-size: 1rem;
    color: #555;
}

.contact-item strong {
    color: #2c3e50;
    margin-right: 0.5rem;
}

.faq-section {
    margin: 2rem 0;
}

.faq-item {
    margin-bottom: 1.5rem;
    padding: 1rem;
    background: #f8f9fa;
    border-radius: 8px;
}

.faq-item h4 {
    color: #2c3e50;
    margin-bottom: 0.5rem;
    font-size: 1.1rem;
}

/* 表单样式 */
.feedback-form {
    margin: 2rem 0;
    max-width: 600px;
}

.form-group {
    margin-bottom: 1.5rem;
}

.form-group label {
    display: block;
    margin-bottom: 0.5rem;
    color: #2c3e50;
    font-weight: 500;
}

.form-group input,
.form-group select,
.form-group textarea {
    width: 100%;
    padding: 0.8rem;
    border: 1px solid #e9ecef;
    border-radius: 8px;
    font-size: 1rem;
    color: #495057;
    background: white;
    transition: all 0.3s ease;
}

.form-group input:focus,
.form-group select:focus,
.form-group textarea:focus {
    outline: none;
    border-color: #667eea;
    box-shadow: 0 0 0 2px rgba(102, 126, 234, 0.2);
}

.form-group textarea {
    resize: vertical;
    min-height: 120px;
}

/* 页脚 */
.footer {
    background: #2c3e50;
    color: white;
    padding: 2rem 2rem 1rem;
}

.footer-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: 1.5rem;
    max-width: 1200px;
    margin: 0 auto 1.5rem;
}

.footer-logo {
    font-size: 1.5rem;
    font-weight: 700;
}

.footer-links {
    display: flex;
    gap: 1.5rem;
    flex-wrap: wrap;
}

.footer-links a {
    color: rgba(255, 255, 255, 0.8);
    text-decoration: none;
    transition: color 0.3s ease;
}

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

.footer-social {
    display: flex;
    gap: 0.8rem;
}

.footer-social a {
    color: white;
    font-size: 1.2rem;
    text-decoration: none;
    transition: transform 0.3s ease;
}

.footer-social a:hover {
    transform: translateY(-3px);
}

.footer-copyright {
    text-align: center;
    color: rgba(255, 255, 255, 0.6);
    padding-top: 1.5rem;
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    font-size: 0.85rem;
}

/* 响应式设计 */
@media (max-width: 768px) {
    .nav {
        flex-direction: column;
        gap: 1rem;
    }

    .nav-links {
        gap: 1rem;
    }

    .hero h1 {
        font-size: 2.5rem;
    }

    .hero p {
        font-size: 1rem;
    }

    h2 {
        font-size: 2rem;
    }

    .cta-buttons {
        flex-direction: column;
        align-items: center;
    }

    .features, .user-groups, .download {
        padding: 4rem 1rem;
    }

    .features-grid, .users-grid {
        grid-template-columns: 1fr;
        gap: 1.5rem;
    }

    .download-buttons {
        flex-direction: column;
        align-items: center;
    }

    .btn-download {
        width: 100%;
        max-width: 300px;
    }

    .footer-content {
        flex-direction: column;
        text-align: center;
    }

    .footer-links {
        justify-content: center;
    }
}

@media (max-width: 480px) {
    .hero h1 {
        font-size: 2rem;
    }

    h2 {
        font-size: 1.8rem;
    }

    .feature-card, .user-card {
        padding: 1.5rem;
    }
}