/* 全局样式 */
:root {
    --apple-bg: #F5F5F7;
    --apple-text: #1D1D1F;
    --apple-blue: #0066CC;
    --apple-gray: #86868B;
    --apple-light-gray: #E8E8ED;
    --apple-card-bg: #FFFFFF;
    --apple-hover: #0071E3;
    --apple-shadow: 0 4px 20px rgba(0, 0, 0, 0.08);
    --container-max-width: 1200px;
    --border-radius: 12px;
}

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

body {
    font-family: -apple-system, BlinkMacSystemFont, "SF Pro Display", "SF Pro Text", "Helvetica Neue", Arial, sans-serif;
    background-color: var(--apple-bg);
    color: var(--apple-text);
    line-height: 1.5;
}

body.menu-open {
    overflow: hidden;
}

/* 容器样式 */
.container {
    width: 100%;
    max-width: var(--container-max-width);
    margin: 0 auto;
    padding: 0 20px;
}

/* 标题样式 */
h1, h2, h3 {
    font-weight: 600;
}

h1 {
    font-size: 2.5rem;
    letter-spacing: -0.5px;
}

h2 {
    font-size: 1.8rem;
    margin-bottom: 1.5rem;
    position: relative;
}

h2:after {
    content: "";
    display: block;
    width: 60px;
    height: 3px;
    background-color: var(--apple-blue);
    position: absolute;
    bottom: -10px;
    left: 0;
}

h3 {
    font-size: 1.2rem;
    margin-bottom: 0.8rem;
}

/* 链接样式 */
a {
    color: var(--apple-blue);
    text-decoration: none;
    transition: color 0.2s ease;
}

a:hover {
    color: var(--apple-hover);
}

/* 头部样式 */
header {
    background-color: rgba(255, 255, 255, 0.8);
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
    box-shadow: 0 1px 0 rgba(0, 0, 0, 0.05);
    position: sticky;
    top: 0;
    z-index: 100;
    padding: 1rem 0;
    transition: box-shadow 0.3s ease;
}

header.scrolled {
    box-shadow: 0 1px 10px rgba(0, 0, 0, 0.1);
}

header .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

/* 导航样式 */
nav {
    background-color: rgba(250, 250, 252, 0.9);
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
    box-shadow: 0 1px 0 rgba(0, 0, 0, 0.05);
    padding: 0.5rem 0;
    position: sticky;
    top: 70px;
    z-index: 90;
    transition: box-shadow 0.3s ease;
}

nav.scrolled {
    box-shadow: 0 1px 10px rgba(0, 0, 0, 0.1);
}

nav ul {
    list-style: none;
    display: flex;
    flex-wrap: wrap;
}

nav ul li {
    margin-right: 2rem;
}

nav ul li a {
    color: var(--apple-text);
    padding: 0.5rem 0;
    display: inline-block;
    position: relative;
    font-weight: 500;
}

nav ul li a:hover {
    color: var(--apple-blue);
}

nav ul li a:after {
    content: "";
    position: absolute;
    bottom: 0;
    left: 0;
    width: 0;
    height: 2px;
    background-color: var(--apple-blue);
    transition: width 0.3s ease;
}

nav ul li a:hover:after {
    width: 100%;
}

/* 主要内容样式 */
main {
    padding: 2rem 0 4rem;
}

/* 网站部分样式 */
.site-section {
    margin-bottom: 4rem;
}

.sub-category {
    color: var(--apple-gray);
    margin: 2rem 0 1rem;
    font-size: 1.3rem;
}

/* 网站卡片网格 */
.site-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    gap: 1.5rem;
    margin-bottom: 2rem;
}

/* 网站卡片样式 */
.site-card {
    background-color: var(--apple-card-bg);
    border-radius: var(--border-radius);
    padding: 1.5rem;
    box-shadow: var(--apple-shadow);
    transition: transform 0.2s ease, box-shadow 0.2s ease, opacity 0.5s ease;
    height: 100%;
    display: flex;
    flex-direction: column;
    opacity: 0;
    transform: translateY(20px);
}

.site-card.visible {
    opacity: 1;
    transform: translateY(0);
}

.site-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 8px 25px rgba(0, 0, 0, 0.12);
}

.site-card h3 {
    display: flex;
    align-items: center;
    margin-bottom: 1rem;
}

.site-card h3 i {
    color: var(--apple-blue);
    margin-right: 0.7rem;
    font-size: 1.2rem;
}

.site-card p {
    color: var(--apple-gray);
    margin-bottom: 1.5rem;
    flex-grow: 1;
}

.site-link {
    display: inline-block;
    padding: 0.6rem 1.2rem;
    background-color: var(--apple-blue);
    color: white;
    border-radius: 20px;
    font-weight: 500;
    transition: background-color 0.2s ease;
    margin-top: auto;
    text-align: center;
}

.site-link:hover {
    background-color: var(--apple-hover);
    color: white;
}

/* 页脚样式 */
footer {
    background-color: var(--apple-light-gray);
    padding: 2rem 0;
    text-align: center;
}

footer p {
    color: var(--apple-gray);
    font-size: 0.9rem;
}

/* 移动端菜单按钮 */
#menu-toggle {
    display: none;
    background: none;
    border: none;
    cursor: pointer;
    font-size: 1.5rem;
    color: var(--apple-text);
}

/* 响应式样式 */
@media (max-width: 768px) {
    .mobile-only {
        display: block;
    }
    
    nav {
        position: fixed;
        top: 0;
        left: 0;
        width: 100%;
        height: 100vh;
        background-color: var(--apple-bg);
        transform: translateX(-100%);
        transition: transform 0.3s ease;
        z-index: 95;
        display: flex;
        align-items: center;
        justify-content: center;
        padding: 2rem;
    }
    
    nav.active {
        transform: translateX(0);
    }
    
    nav ul {
        flex-direction: column;
        align-items: center;
        width: 100%;
    }
    
    nav ul li {
        margin: 1rem 0;
        width: 100%;
        text-align: center;
    }
    
    nav ul li a {
        font-size: 1.5rem;
        padding: 0.7rem 0;
        display: block;
    }
    
    h1 {
        font-size: 1.8rem;
    }
    
    h2 {
        font-size: 1.5rem;
    }
    
    .site-grid {
        grid-template-columns: 1fr;
    }
}

@media (max-width: 480px) {
    .container {
        padding: 0 15px;
    }
    
    h1 {
        font-size: 1.5rem;
    }
    
    h2 {
        font-size: 1.3rem;
    }
    
    .site-card {
        padding: 1.2rem;
    }
}