/* 全局变量 */
:root {
    --primary-color: #fff;
    --text-color: #222;
    --footer-text-color: #ccc;
    --footer-bg-color: rgba(0, 0, 0, 0.5);
    --nav-active-border: rgba(255, 255, 255, 0.5);
    --download-btn-bg: #fff;
    --download-btn-color: #222;
    --qrcode-bg: #fff;
}

/* 全局样式 */
a {
    text-decoration: none;
    color: inherit;
}

/* 重置和基础样式 */
* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

/* fullpage导航样式 */
#fp-nav ul li a span {
    background-color: red;
}

/* 页面布局 */
.section {
    position: relative;
    background-size: cover;
    background-position: center;
    background-repeat: no-repeat;
}

.container {
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 100%;
    max-width: 690px;
    margin: 0 auto;
    padding: 0 20px;
}

.app_main_ui {
    width: 300px;
}

.container_app_info {
    width: 232px;
    padding-top: 68px;
}

.app_logo {
    width: 60px;
    height: 60px;
    border-radius: 25%;
}

.title {
    margin-top: 22.4px;
}

.title h1 {
    font-weight: 600;
    font-size: 22.4px;
    color: var(--primary-color);
}

.connect h2 {
    font-weight: 500;
    font-size: 16px;
    color: var(--primary-color);
}

.download-container {
    display: inline-block;
    margin-top: 35.2px;
}

.download-container button {
    display: block;
    width: 182.4px;
    height: 46.08px;
    background-color: var(--download-btn-bg);
    font-size: 15.84px;
    color: var(--download-btn-color);
    border: 1px solid var(--primary-color);
    border-radius: 23.04px;
    cursor: pointer;
    transition: all 0.3s ease;
}

.download-container button:hover {
    background-color: rgba(255, 255, 255, 0.9);
    transform: translateY(-2px);
}

.download-container {
    position: relative;
    display: inline-block;
    margin-top: 35.2px;
}

.download_qrcode {
    position: absolute;
    top: 100%;
    left: 50%;
    transform: translateX(-50%);
    box-sizing: border-box;
    padding: 3.6px;
    margin-top: 10px;
    background-color: var(--qrcode-bg);
    border-radius: 14.8px;
    z-index: 10;
    opacity: 0;
    visibility: hidden;
    transition: opacity 0.3s ease, visibility 0.3s ease;
}

.download-container:hover .download_qrcode {
    opacity: 1;
    visibility: visible;
}

.download_qrcode img {
    width: 174.4px;
    height: 174.4px;
}

/* 页面背景 */
.section1 {
    background-image: url(./../image/bg_private_camera.jpeg);
}

.section2 {
    background-image: url(./../image/bg_secret_shoot1.jpeg);
}

.section3 {
    background-image: url(./../image/bg_position_monitor.jpeg);
}

.section4 {
    background-image: url(http://idowebok.u.qiniudn.com/77/4.jpg);
}

/* 头部导航 */
.header {
    position: fixed;
    top: 20px;
    right: 10%;
    z-index: 1000;
}

.navigation-bar {
    list-style-type: none;
    display: flex;
    flex-direction: row;
    justify-content: flex-end;
    align-items: center;
}

.navigation-bar .nav-item {
    color: var(--primary-color);
    margin-left: 36px;
    text-decoration: none;
    line-height: 36px;
    cursor: pointer;
    transition: all 0.3s ease;
}

.navigation-bar .nav-item:hover {
    opacity: 0.8;
}

.active_tab {
    border-bottom: 2px solid var(--nav-active-border);
}

/* 页脚 */
.footer.home-footer {
    position: fixed;
    bottom: 16px;
    left: 50%;
    transform: translateX(-50%);
    z-index: 1000;
}

.bottom .info {
    display: flex;
    width: 100%;
    font-size: 12px;
    line-height: 18px;
    font-weight: 400;
    color: var(--footer-text-color);
    justify-content: center;
}

.bottom .info .line {
    text-align: center;
    border-radius: 26px;
    padding: 10px 26px;
    background: var(--footer-bg-color);
}

/* 响应式设计 */
@media (max-width: 768px) {
    .container {
        flex-direction: column;
        text-align: center;
        max-width: 90%;
        padding: 0 10px;
    }
    
    .app_main_ui {
        width: 250px;
        margin-bottom: 20px;
    }
    
    .container_app_info {
        width: 100%;
        padding-top: 0;
    }
    
    .header {
        right: 5%;
    }
    
    .navigation-bar .nav-item {
        margin-left: 20px;
        font-size: 14px;
    }
}

@media (max-width: 600px) {
    .app_main_ui {
        display: none;
    }
    
    .header {
        display: none;
    }
    
    .footer.home-footer {
        display: none;
    }
    
    .title h1 {
        font-size: 20px;
    }
    
    .connect h2 {
        font-size: 14px;
    }
    
    .download-container button {
        width: 160px;
        height: 40px;
        font-size: 14px;
    }
    
    .download_qrcode img {
        width: 150px;
        height: 150px;
    }
}

@media (max-width: 480px) {
    .title h1 {
        font-size: 18px;
    }
    
    .connect h2 {
        font-size: 12px;
    }
    
    .download-container button {
        width: 140px;
        height: 36px;
        font-size: 13px;
    }
    
    .download_qrcode img {
        width: 130px;
        height: 130px;
    }
}