/* 基础样式 */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
    line-height: 1.6;
    color: #333;
    background-color: #f5f5f7;
}

.container {
    max-width: 1000px;
    margin: 0 auto;
    padding: 0 20px;
}

/* 头部 */
header {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    padding: 40px 0;
    text-align: center;
}

header h1 {
    font-size: 2.5em;
    margin-bottom: 10px;
}

.tagline {
    font-size: 1.2em;
    opacity: 0.9;
}

/* 导航 */
nav {
    background: white;
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
    position: sticky;
    top: 0;
    z-index: 100;
}

nav .container {
    display: flex;
    justify-content: center;
    gap: 40px;
    padding: 15px 20px;
}

nav a {
    color: #333;
    text-decoration: none;
    font-weight: 500;
    transition: color 0.3s;
}

nav a:hover,
nav a.active {
    color: #667eea;
}

/* 主要内容 */
main {
    padding: 40px 20px;
}

section {
    background: white;
    border-radius: 12px;
    padding: 40px;
    margin-bottom: 30px;
    box-shadow: 0 2px 8px rgba(0,0,0,0.08);
}

h2 {
    font-size: 2em;
    margin-bottom: 20px;
    color: #1d1d1f;
}

h3 {
    font-size: 1.5em;
    margin-bottom: 20px;
    color: #1d1d1f;
}

h4 {
    font-size: 1.2em;
    margin-bottom: 15px;
    color: #333;
}

/* 首页样式 */
.hero {
    text-align: center;
    padding: 60px 40px;
}

.hero h2 {
    font-size: 2.5em;
    margin-bottom: 15px;
}

.subtitle {
    font-size: 1.3em;
    color: #666;
}

.feature-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 30px;
    margin-top: 30px;
}

.feature-card {
    padding: 30px;
    background: #f9f9fb;
    border-radius: 8px;
    transition: transform 0.3s;
}

.feature-card:hover {
    transform: translateY(-5px);
}

.feature-card h4 {
    color: #667eea;
    margin-bottom: 15px;
}

.download {
    text-align: center;
}

.app-info {
    margin-top: 30px;
    padding: 20px;
    background: #f9f9fb;
    border-radius: 8px;
    display: inline-block;
}

.app-info p {
    margin: 10px 0;
    font-size: 1.1em;
}

.highlights ul {
    list-style: none;
    padding-left: 0;
}

.highlights li {
    padding: 15px 0;
    border-bottom: 1px solid #eee;
}

.highlights li:last-child {
    border-bottom: none;
}

.highlights li:before {
    content: "✓ ";
    color: #667eea;
    font-weight: bold;
    margin-right: 10px;
}

.example-list {
    display: flex;
    flex-direction: column;
    gap: 20px;
    margin-top: 20px;
}

.example-item {
    display: flex;
    align-items: center;
    padding: 20px;
    background: #f9f9fb;
    border-radius: 8px;
    gap: 15px;
}

.example-item .input {
    flex: 1;
    font-weight: 500;
    color: #333;
}

.example-item .arrow {
    color: #667eea;
    font-size: 1.5em;
}

.example-item .output {
    flex: 1;
    font-weight: 600;
    color: #667eea;
    text-align: right;
}

/* 内容页面样式 */
.content {
    background: white;
    border-radius: 12px;
    padding: 50px;
    box-shadow: 0 2px 8px rgba(0,0,0,0.08);
}

.content section {
    background: none;
    padding: 30px 0;
    box-shadow: none;
    margin-bottom: 0;
    border-bottom: 1px solid #eee;
}

.content section:last-child {
    border-bottom: none;
}

.update-date {
    color: #666;
    font-style: italic;
    margin-bottom: 30px;
}

.content ul {
    margin-left: 30px;
    margin-top: 15px;
}

.content li {
    margin: 10px 0;
}

.content a {
    color: #667eea;
    text-decoration: none;
}

.content a:hover {
    text-decoration: underline;
}

/* 隐私政策特殊样式 */
.summary {
    background: #f0f4ff;
    padding: 30px;
    border-radius: 8px;
    margin-top: 30px;
}

.commitment p {
    margin: 15px 0;
    font-size: 1.1em;
}

/* 联系页面样式 */
.contact-info {
    margin: 30px 0;
}

.contact-item {
    padding: 30px;
    background: #f9f9fb;
    border-radius: 8px;
    margin-bottom: 20px;
}

.contact-item h4 {
    color: #667eea;
    margin-bottom: 15px;
}

.contact-item a {
    color: #667eea;
    text-decoration: none;
    font-size: 1.2em;
    font-weight: 500;
}

.contact-item a:hover {
    text-decoration: underline;
}

.note {
    color: #666;
    font-size: 0.9em;
    margin-top: 10px;
}

.faq {
    margin-top: 30px;
}

.faq-item {
    margin-bottom: 30px;
    padding-bottom: 30px;
    border-bottom: 1px solid #eee;
}

.faq-item:last-child {
    border-bottom: none;
}

.faq-item h4 {
    color: #667eea;
    margin-bottom: 10px;
}

.faq-item p {
    color: #333;
    line-height: 1.8;
}

.contact-box {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    padding: 40px;
    border-radius: 12px;
    margin-top: 40px;
}

.contact-box h3 {
    color: white;
    margin-bottom: 25px;
}

.contact-details {
    font-size: 1.1em;
}

.contact-details p {
    margin: 15px 0;
}

.contact-details .email {
    font-size: 1.3em;
    font-weight: 600;
    margin: 20px 0;
}

.contact-details .email a {
    color: white;
    text-decoration: none;
}

.contact-details .email a:hover {
    text-decoration: underline;
}

.contact-details .note {
    color: rgba(255,255,255,0.9);
    font-style: italic;
}

/* 页脚 */
footer {
    background: #1d1d1f;
    color: white;
    text-align: center;
    padding: 30px 0;
    margin-top: 50px;
}

footer p {
    margin: 10px 0;
}

footer a {
    color: white;
    text-decoration: none;
    margin: 0 10px;
}

footer a:hover {
    text-decoration: underline;
}

/* 响应式设计 */
@media (max-width: 768px) {
    header h1 {
        font-size: 2em;
    }
    
    .tagline {
        font-size: 1em;
    }
    
    nav .container {
        gap: 20px;
    }
    
    section {
        padding: 30px 20px;
    }
    
    .content {
        padding: 30px 20px;
    }
    
    .hero h2 {
        font-size: 1.8em;
    }
    
    .subtitle {
        font-size: 1.1em;
    }
    
    .feature-grid {
        grid-template-columns: 1fr;
    }
    
    .example-item {
        flex-direction: column;
        align-items: flex-start;
    }
    
    .example-item .output {
        text-align: left;
    }
}