/* 核心变量：纯白+冷蓝色调+高明亮度 */
:root {
    --color-primary: #4f86f7;      /* 冷蓝色主调 */
    --color-primary-dark: #3b74e3; /* 深冷蓝 */
    --color-dark: #2d3748;         /* 深灰文本 */
    --color-gray: #718096;         /* 中灰色 */
    --color-light-gray: #e2e8f0;   /* 浅灰色边框 */
    --color-white: #ffffff;        /* 纯白背景 */
    --color-light-bg: rgba(79, 134, 247, 0.05); /* 极浅冷蓝背景 */
    
    --radius-sm: 8px;
    --radius-md: 12px;
    --radius-lg: 16px;
    --transition-fast: 0.2s ease;
    --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.03);
    --shadow-md: 0 4px 6px rgba(0, 0, 0, 0.05);
}

/* 重置与基础 */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html, body {
    height: 100%;
    background: var(--color-white); /* 纯白背景 */
    color: var(--color-dark);
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "PingFang SC", "Microsoft YaHei", sans-serif;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

::selection {
    background-color: rgba(79, 134, 247, 0.15); /* 冷蓝选中文本背景 */
    color: var(--color-primary-dark);
}

/* 美化滚动条 - 冷蓝色调 */
::-webkit-scrollbar {
    width: 8px;
}
::-webkit-scrollbar-track {
    background: var(--color-white);
}
::-webkit-scrollbar-thumb {
    background: var(--color-primary);
    border-radius: var(--radius-sm);
}
::-webkit-scrollbar-thumb:hover {
    background: var(--color-primary-dark);
}

/* 主要内容容器 */
.main-container {
    width: 100%;
    min-height: 100vh;
}

/* 导航栏 - 冷蓝色风格 */
.nav-header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    background: var(--color-white);
    box-shadow: var(--shadow-sm);
    z-index: 1000;
}

.nav-container {
    max-width: 900px;
    margin: 0 auto;
    padding: 0 20px;
}

.nav-main {
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 60px;
}

.nav-logo {
    display: flex;
    align-items: center;
    gap: 10px;
    text-decoration: none;
    color: var(--color-dark);
    font-weight: 700;
    font-size: 1.2rem;
}

.nav-logo i {
    color: var(--color-primary);
}

/* 页面标题 */
.page-header {
    padding: 100px 20px 20px;
    text-align: center;
}

.page-title {
    font-size: 1.8rem;
    font-weight: 700;
    line-height: 1.1;
    margin-bottom: 8px;
    color: var(--color-dark);
}

/* 内容容器 */
.content-container {
    max-width: 900px;
    margin: 0 auto;
    padding: 0 20px 40px;
}

/* 公告详情卡片 - 冷蓝色风格 */
.announcement-card {
    background: var(--color-white);
    border: 1px solid var(--color-light-gray);
    border-radius: var(--radius-lg);
    overflow: hidden;
    margin-bottom: 20px;
    transition: all var(--transition-fast);
}

.announcement-card:hover {
    box-shadow: var(--shadow-md);
    border-color: rgba(79, 134, 247, 0.2);
}

.announcement-header {
    padding: 20px;
    border-bottom: 1px solid var(--color-light-gray);
}

.announcement-title {
    font-size: 1.3rem;
    font-weight: 700;
    color: var(--color-dark);
    line-height: 1.4;
    margin-bottom: 12px;
}

.announcement-meta {
    display: flex;
    justify-content: space-between;
    align-items: center;
    color: var(--color-gray);
    font-size: 0.9rem;
}

.announcement-time {
    display: flex;
    align-items: center;
    gap: 8px;
}

.announcement-time i {
    color: var(--color-primary);
}

.announcement-site {
    font-weight: 600;
    color: var(--color-primary);
}

.announcement-content {
    padding: 20px;
    line-height: 1.6;
    font-size: 1rem;
    color: var(--color-dark);
}

.announcement-content p {
    margin-bottom: 1.2em;
}

.announcement-content p:last-child {
    margin-bottom: 0;
}

/* 操作按钮 - 冷蓝色风格 */
.action-buttons {
    display: flex;
    justify-content: center;
    gap: 10px;
    margin: 30px 0;
    flex-wrap: wrap;
}

.action-btn {
    display: flex;
    align-items: center;
    gap: 8px;
    background: var(--color-white);
    border: 1px solid var(--color-light-gray);
    border-radius: var(--radius-md);
    padding: 12px 20px;
    color: var(--color-dark);
    font-weight: 600;
    text-decoration: none;
    transition: all var(--transition-fast);
}

.action-btn:hover {
    background: var(--color-light-bg);
    border-color: rgba(79, 134, 247, 0.3);
    transform: translateY(-2px);
    box-shadow: var(--shadow-sm);
}

.action-btn i {
    color: var(--color-primary);
}

.btn-purchase {
    background: var(--color-primary);
    border-color: rgba(79, 134, 247, 0.3);
    color: var(--color-white);
}

.btn-purchase:hover {
    background: var(--color-primary-dark);
    color: var(--color-white);
}

/* 页脚 - 冷蓝色风格 */
.footer {
    background: var(--color-white);
    border-top: 1px solid var(--color-light-gray);
    padding: 30px 20px;
    text-align: center;
}

.footer-logo {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 10px;
    text-decoration: none;
    color: var(--color-dark);
    font-weight: 700;
    font-size: 1.2rem;
    margin-bottom: 20px;
}

.footer-logo i {
    color: var(--color-primary);
}

.footer-copy {
    color: var(--color-gray);
    font-size: 0.8rem;
}

/* 响应式设计 */
@media (max-width: 768px) {
    .page-header {
        padding: 80px 20px 20px;
    }
    
    .page-title {
        font-size: 1.5rem;
    }
    
    .announcement-title {
        font-size: 1.2rem;
    }
    
    .announcement-meta {
        flex-direction: column;
        align-items: flex-start;
        gap: 8px;
    }
    
    .action-buttons {
        flex-direction: column;
        align-items: stretch;
    }
    
    .action-btn {
        justify-content: center;
    }
    
    .content-container {
        padding: 0 16px 20px;
    }
}