/* --- 基础重设 --- */
* { margin: 0; padding: 0; box-sizing: border-box; }
html, body {
    width: 100%;
    min-height: 100vh;
    background-image: url('images/about-bg.png'); 
    background-size: cover;
    background-position: center top;
    background-repeat: no-repeat;
    background-attachment: fixed;
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
}

/* --- 顶部导航（静态占位） --- */
.about-top-nav {
    position: fixed;
    top: 20px;
    left: 50%;
    transform: translateX(-50%);
    display: flex;
    gap: 6px;
    z-index: 100;
}
.about-top-nav .nav-item {
    font-size: 14px;
    font-weight: bold;
    color: #333;
    text-decoration: none;
    padding: 8px 18px;
    border-radius: 20px;
    background: rgba(255,255,255,0.3);
    transition: all 0.3s;
}
.about-top-nav .nav-item.active {
    background: #578a6c;   /* 选中状态的深绿色 */

}

/* --- 内容区域 --- */
.about-container {
    width: 100%;
    padding: 180px 20px 80px 20px; /* 顶部留出导航空间，底部留白 */
    display: flex;
    justify-content: center;
}

.about-title {
    font-size: 32px;
    font-weight: bold;
    color: #332222;
    margin-bottom: 40px;
    letter-spacing: 6px;
}

/* --- 底部黑色页脚 --- */
.about-footer {
    background-color: #000000;
    width: 100%;
    padding: 40px 20px;
    display: flex;
    justify-content: center;
}
.footer-content-wrapper {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 20px;
}
.footer-logo img {
    width: 120px;
    height: auto;
}
.footer-text img {
    max-width: 800px;
    width: 100%;
    height: auto;
}

/* --- 移动端适配 --- */
@media (max-width: 768px) {
    .about-top-nav {
        top: 10px;
        gap: 4px;
        transform: translateX(-50%) scale(0.7);
    }
    .about-title { font-size: 24px; }
    .about-content-wrapper { padding: 20px; }
    .text-paragraph { font-size: 14px; line-height: 1.6; }
}