@import url('https://fonts.googleapis.com/css2?family=Playfair+Display:wght@700&display=swap');

/* 合作页面样式 - 白宫风格 */

body, html {
    margin: 0;
    padding: 0;
    width: 100%;
    height: auto;
    min-height: 100%;
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
    overflow-x: hidden; /* 禁止左右滚动 */
    overflow-y: visible; /* 允许垂直滚动 */
    background-color: #fff; /* 设置白色背景消除灰色区域 */
}

/* 页面滚动锁定：仅在展示 hero 时给 body 加上 .no-scroll */
body.no-scroll {
    overflow: hidden !important;
    height: 100vh;
}

/* Change header background only on cooperation page */
header.main-header.cooperation-active {
    background-color: #001b44 !important; /* 深蓝色 */
    transition: background-color 0.3s ease;
    backdrop-filter: none !important;
    -webkit-backdrop-filter: none !important;
}

/* Hero Section Styles */
.hero-section {
    position: relative;
    width: 100%;
    height: calc(100vh - 68px); /* Match actual header height */
    overflow: hidden;
    cursor: pointer;
    background-color: #001b44; /* Fallback color */
}

.hero-image-container {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
}

.hero-image {
    width: 100%;
    height: 100%;
    object-fit: cover;
    display: block;
}

.hero-image-container::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 100%;
    height: 40%; /* 从图片下方40%开始模糊 */
    background: linear-gradient(to bottom, 
                               rgba(0, 0, 0, 0) 0%,
                               rgba(0, 0, 0, 0.3) 30%,
                               rgba(0, 27, 68, 0.9) 100%);
    pointer-events: none;
}

.hero-overlay {
    position: absolute;
    top: 70%; /* 继续向下移动 */
    left: 50%;
    transform: translate(-50%, -50%);
    z-index: 10;
    color: white;
    text-align: center;
    width: 90%;
    pointer-events: none; /* Let clicks go through to the section */
}

.hero-title {
    font-family: 'Merriweather', Georgia, serif; /* Match article title font */
    font-size: 4rem; /* 缩小主标题 */
    font-weight: 700;
    color: #fff;
    margin: 0;
    line-height: 1.1;
    text-shadow: 0 2px 8px rgba(0,0,0,0.5);
}

.hero-scroll-btn {
    display: block;
    margin-top: 30px;
    color: #fff;
    text-decoration: none;
    font-size: 1.35rem; /* 副标题更大 */
    font-weight: 400;
    pointer-events: auto; /* Make the button clickable */
    transition: all 0.2s ease;
    letter-spacing: 0.5px;
}

.hero-scroll-btn:hover {
    text-decoration: underline;
}

/* Article Section Styles */
.article-section {
    display: none;
    background-color: #fff;
    padding: 0;
    min-height: calc(100vh - 68px); /* 至少占满视窗可视高度 */
    height: auto; /* 自适应内容高度，使用页面滚动 */
    overflow-y: auto; /* 允许垂直滚动 */
    overflow-x: hidden; /* 禁止水平滚动 */
}

/* 页脚样式 */
.page-footer {
    background-color: #001b44;
    padding: 20px 0;
    text-align: center;
    width: 100%;
    margin-top: 40px;
}

.article-header {
    /* 上浅下深的深蓝渐变，与参考图一致 */
    background: linear-gradient(to bottom, #0c2548 0%, #072544 30%, #001b44 70%, #001634 100%);
    color: white;
    padding: 20px 10%; /* 减小上下内边距，整体上移 */
    display: flex;
    flex-direction: column;
    align-items: center;
    position: relative;
    border-top: 1px solid #aaaaaa; /* 顶部灰色细线 */
    justify-content: center;
    min-height: 300px; /* 确保有足够高度来居中 */
}

.back-to-top-btn {
    background-color: transparent;
    color: white;
    border: 1px solid white;
    border-radius: 30px;
    padding: 8px 20px;
    font-family: system-ui, -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    font-size: 14px;
    cursor: pointer;
    transition: all 0.3s ease;
}

.back-to-top-btn:hover {
    background-color: rgba(255, 255, 255, 0.1);
}

/* 文章页标题上方的居中提示文字 */
.article-kicker {
    text-align: center;
    color: #ffffff;
    font-size: 1rem; /* 与作者span一致 */
    letter-spacing: 0.12em;
    opacity: 0.9;
    margin: 6px auto 10px;
}

.back-to-articles {
    color: #fff;
    text-decoration: underline;
    font-size: 1rem;
    font-weight: 600;
    display: inline-block;
    position: absolute;
    top: 16px;
    left: 16px; /* 更靠左 */
}

.back-to-articles:hover {
    text-decoration: underline;
}

.article-title {
    font-family: 'Merriweather', Georgia, serif; /* 更接近白宫风格且数字不塌陷 */
    font-size: 2.8rem;
    font-weight: 700;
    margin: 20px auto; /* 居中 */
    max-width: 900px;
    text-align: center; /* 文本居中 */
    line-height: 1.2;
    color: #fff;
    font-variant-numeric: lining-nums; /* 使用等高数字 */
    font-feature-settings: "lnum" 1, "liga" 0; /* 关闭连字，启用等高数字 */
}

.article-meta {
    display: flex;
    justify-content: center; /* 居中 */
    align-items: center;
    gap: 0;
    color: rgba(255,255,255,0.8);
    font-size: 1rem;
    margin-top: 15px;
}

.article-author::after {
    content: '|';
    margin: 0 15px;
    color: rgba(255,255,255,0.5);
    font-weight: 300;
}

.article-content {
    padding: 2rem 20%;
    line-height: 1.6;
    font-size: 1.2rem; /* 增加整体字体大小 */
    max-width: 1200px;
    margin: 0 auto;
}

.article-content .bullet-list {
    list-style-type: none;
    padding-left: 0;
    margin-top: 1.5rem;
}

.article-content .bullet-list li {
    position: relative;
    padding-left: 2rem;
    margin-bottom: 1.5rem;
}

.article-content .bullet-point {
    position: absolute;
    left: 0;
    top: 0.6rem;
    width: 8px;
    height: 8px;
    background-color: #aaaaaa; /* 浅灰色圆形标识 */
    border-radius: 50%;
    display: inline-block;
}

.disclaimer {
    font-size: 0.85rem;
    font-style: italic;
    color: #777;
    margin-top: 2rem;
    text-align: center;
}

.article-lead {
    font-size: 1.5rem;
    line-height: 1.4;
    color: #333;
    margin-bottom: 30px;
    font-weight: 300;
}

.article-content h3 {
    font-size: 1.8rem;
    margin: 40px 0 20px;
    color: #001b44;
}

.article-content p {
    margin-bottom: 20px;
    font-size: 1.1rem;
}

.article-content ul {
    margin-bottom: 30px;
    padding-left: 20px;
}

.article-content li {
    margin-bottom: 10px;
    font-size: 1.1rem;
}

.cta-box {
    margin-top: 60px;
    padding: 30px;
    background-color: #f5f8ff;
    border-radius: 8px;
    border-left: 4px solid #001b44;
    text-align: center;
}

.cta-box h4 {
    font-size: 1.4rem;
    margin: 0 0 10px 0;
    color: #001b44;
}

.cta-button {
    background-color: #001b44;
    color: white;
    border: none;
    padding: 12px 30px;
    border-radius: 6px;
    font-size: 1rem;
    margin-top: 20px;
    cursor: pointer;
    transition: background-color 0.2s ease;
}

.cta-button:hover {
    background-color: #002b69;
}

/* 响应式设计 */
@media (max-width: 768px) {
    .hero-title {
        font-size: 3rem;
    }
    
    .hero-overlay {
        bottom: 10%;
        padding: 0 5%;
    }
    
    .article-header {
        padding: 30px 5%;
    }
    
    .article-title {
        font-size: 1.8rem;
    }
    
    .article-content {
        padding: 30px 5%;
    }
    
    .article-lead {
        font-size: 1.2rem;
    }
}