/* 全局样式（） */
* {margin: 0;padding: 0;box-sizing: border-box;}
body {font-family: "Microsoft YaHei", sans-serif;background: #f5f7fa;color: #333;line-height: 1.8;}
.header, .footer {background: #2c3e50;color: #fff;}
/* 修复菜单栏样式 - 提升优先级 */
.navbar-dark .navbar-brand {color: #fff !important;} /* 品牌文字颜色 */
.navbar-dark .navbar-nav .nav-link {color: #fff !important;transition: all 0.3s;}
.navbar-dark .navbar-nav .nav-link.active {color: #3498db !important;} /* 激活状态颜色 */
.navbar-dark .navbar-nav .nav-link:hover {color: #3498db !important;}
.navbar-dark .navbar-toggler {border-color: rgba(255,255,255,0.2);} /* 小屏展开按钮边框 */
.navbar-dark .navbar-toggler-icon {background-image: url("data:image/svg+xml,%3csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 30 30'%3e%3cpath stroke='rgba%28255, 255, 255, 0.55%29' stroke-linecap='round' stroke-miterlimit='10' stroke-width='2' d='M4 7h22M4 15h22M4 23h22'/%3e%3c/svg%3e");}
/* 自定义container-xl宽度（确保PC端严格1200px） */
@media (min-width: 1200px) {
    .container-xl {
        max-width: 1200px !important;
    }
}
/* 新增：返回顶部按钮样式 */
.back-to-top-btn {
    position: fixed; /* 固定定位 */
    bottom: 30px; /* 距离底部30px */
    right: 30px; /* 距离右侧30px */
    width: 50px;
    height: 50px;
    border: none;
    border-radius: 50%; /* 圆形按钮 */
    background-color: #3498db; /* 和导航hover颜色一致 */
    color: #fff;
    font-size: 24px;
    cursor: pointer;
    box-shadow: 0 3px 10px rgba(52, 152, 219, 0.3);
    transition: all 0.3s ease;
    z-index: 9999; /* 置顶显示，不被其他元素遮挡 */
}
.back-to-top-btn:hover {
    background-color: #2980b9; /* hover加深颜色 */
    transform: translateY(-3px); /* 轻微上移 */
    box-shadow: 0 5px 15px rgba(52, 152, 219, 0.4);
}
/* 移动端适配返回顶部按钮 */
@media (max-width: 576px) {
    .back-to-top-btn {
        width: 45px;
        height: 45px;
        font-size: 20px;
        bottom: 20px;
        right: 20px;
    }
}
.main-title {font-size: 2.5rem;font-weight: 700;margin: 2rem 0;color: #2c3e50;}
.sub-title {font-size: 1.5rem;font-weight: 500;color: #3498db;margin: 1rem 0;}
.download-card {background: #fff;border-radius: 10px;box-shadow: 0 2px 15px rgba(0,0,0,0.05);padding: 2rem;margin: 2rem 0;}
.download-btn {display: block;width: 100%;max-width: 400px;height: 60px;line-height: 60px;text-align: center;border-radius: 8px;font-size: 1.2rem;font-weight: 600;text-decoration: none;margin: 1rem auto;transition: all 0.3s;}
.btn-baidu {background: #2772fb;color: #fff;}
.btn-baidu:hover {background: #165dff;color: #fff;transform: translateY(-3px);box-shadow: 0 5px 15px rgba(39,114,251,0.3);}
.btn-quark {background: #44c662;color: #fff;}
.btn-quark:hover {background: #36b352;color: #fff;transform: translateY(-3px);box-shadow: 0 5px 15px rgba(68,198,98,0.3);}
.content-box {background: #fff;border-radius: 10px;box-shadow: 0 2px 15px rgba(0,0,0,0.05);padding: 2rem;margin: 1rem 0;}
.faq-item {margin: 1.5rem 0;padding-bottom: 1rem;border-bottom: 1px solid #eee;}
.faq-title {font-weight: 600;color: #2c3e50;}
/* 截图展示区样式 */
.screenshot-box {margin: 2rem 0;text-align: center;}
.screenshot-title {font-size: 1.3rem;font-weight: 600;color: #2c3e50;margin-bottom: 1.5rem;}
.screenshot-container {display: flex;flex-wrap: wrap;justify-content: center;gap: 1.5rem;margin-bottom: 1rem;}
.screenshot-img {max-width: 100%;width: 300px;border-radius: 8px;box-shadow: 0 3px 10px rgba(0,0,0,0.1);transition: transform 0.3s;}
.screenshot-img:hover {transform: scale(1.02);}
.screenshot-desc {color: #666;font-size: 0.9rem;margin-top: 0.5rem;}
/* 自适应媒体查询 */
@media (max-width: 768px) {
    .main-title {font-size: 1.8rem;}
    .sub-title {font-size: 1.2rem;}
    .download-card, .content-box {padding: 1.5rem;}
    .download-btn {font-size: 1rem;height: 50px;line-height: 50px;}
    .screenshot-img {width: 250px;}
}
@media (max-width: 576px) {
    .main-title {font-size: 1.5rem;}
    .nav {justify-content: center !important;}
    .screenshot-img {width: 100%;max-width: 300px;}
}