/* 全局重置 */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  background-color: #F8FAFC;
  color: #1F2937;
  line-height: 1.7;
}

/* 导航栏全局样式 */
.header {
    background-color: #0F172A;
    padding: 16px 24px;
    color: #ffffff;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
}

.nav-wrap {
    max-width: 1200px;
    margin: 0 auto;
    display: grid;
    grid-template-columns: auto 1fr;
    grid-template-rows: auto auto;
    gap: 8px 16px;
    align-items: center;
}

/* Logo核心样式：图片在左，文字在右 */
.lab-logo {
    grid-row: 1 / 3; /* Logo占两行 */
    display: flex;
    flex-direction: row; /* 强制横向排列，图片左、文字右 */
    align-items: center;
    gap: 12px; /* 图片和文字间距 */
    text-decoration: none;
    color: #ffffff;
    font-size: 24px;
    font-weight: 700;
    letter-spacing: 1px;
    white-space: nowrap; /* 防止文字换行挤压图片 */
}

/* Logo图片样式 */
.logo-img {
    width: 60px;
    height: 60px;
    object-fit: contain;
    display: inline-block;
    transform: translateY(6px);
}

/* Logo文字样式 */
.logo-text {
    line-height: 1.2;
    display: inline-block;
    align-items: center;
}

/* 导航菜单样式 */
.nav {
    grid-column: 2 / 3;
    grid-row: 1 / 2;
    display: flex;
    justify-content: flex-end;
    gap: 32px;
}

.nav a {
    color: #E2E8F0;
    text-decoration: none;
    font-size: 16px;
    font-weight: 500;
    padding: 8px 0;
    position: relative;
    transition: color 0.2s ease;
}

.nav a:hover {
    color: #93C5FD;
}

.nav a.active {
    color: #ffffff;
    font-weight: 600;
}

.nav a.active::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 100%;
    height: 2px;
    background-color: #3B82F6;
    border-radius: 2px;
}

/* 语言切换按钮样式 */
.lang-switch {
    grid-column: 2 / 3;
    grid-row: 2 / 3;
    display: flex;
    justify-content: flex-end;
    gap: 8px;
}

.lang-btn {
    padding: 6px 16px;
    border-radius: 8px;
    border: 1px solid #3B82F6;
    background-color: transparent;
    color: #E2E8F0;
    font-size: 14px;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.2s ease;
}

.lang-btn.active {
    background-color: #3B82F6;
    color: #ffffff;
}

.lang-btn:hover:not(.active) {
    border-color: #60A5FA;
    color: #93C5FD;
}

/* 全局容器样式 */
.container {
    max-width: 1200px;
    margin: 40px auto;
    padding: 0 24px;
}

.card {
    background-color: #ffffff;
    border-radius: 16px;
    padding: 48px;
    box-shadow: 0 2px 12px rgba(0, 0, 0, 0.05);
    border: 1px solid #F1F5F9;
}

/* 页脚全局样式 */
.footer {
    background-color: #0F172A;
    color: #E2E8F0;
    padding: 24px;
    text-align: center;
    margin-top: 60px;
    font-size: 15px;
}

.footer strong {
    color: #ffffff;
    font-weight: 600;
}

/* 全局响应式适配 - 768px以下全部居中 */
@media (max-width: 768px) {
    .header {
        text-align: center; /* 基础文本居中 */
    }
    
    .nav-wrap {
        grid-template-columns: 1fr;
        grid-template-rows: auto auto auto;
        gap: 12px;
        display: flex; /* 改用flex更易全局居中 */
        flex-direction: column;
        align-items: center; /* 所有子元素水平居中 */
    }

    .lab-logo {
        grid-row: 1 / 2;
        justify-content: center; /* Logo整体居中 */
        font-size: 20px;
    }

    .logo-img {
        width: 55px;
        height: 55px;
    }

    .nav {
        grid-column: 1 / 2;
        grid-row: 2 / 3;
        justify-content: center; /* 导航菜单居中 */
        gap: 20px;
        flex-wrap: wrap;
    }

    .nav a {
        font-size: 15px;
    }

    .lang-switch {
        grid-column: 1 / 2;
        grid-row: 3 / 4;
        justify-content: center; /* 语言切换按钮居中 */
    }

    .card {
        padding: 32px 24px;
    }
}

@media (max-width: 480px) {
    .header {
        padding: 12px 16px;
    }

    .lab-logo {
        font-size: 18px;
        gap: 8px;
    }

    .logo-img {
        width: 45px;
        height: 45px;
    }
    
    .nav {
        gap: 16px; /* 更小屏幕缩小导航间距 */
    }

    .nav a {
        font-size: 14px;
    }

    .container {
        margin: 24px auto;
        padding: 0 16px;
    }

    .card {
        padding: 24px 16px;
    }

    .footer {
        padding: 20px 16px;
        font-size: 14px;
    }
}