* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: "Microsoft YaHei", sans-serif;
}

/* 全局样式 */
:root {
    --primary: #409eff;
    --primary-dark: #337ecc;
    --dark: #1f2937;
    --light: #f9fafb;
    --gray: #6b7280;
}

body {
    scroll-behavior: smooth;
}

section {
    padding: 80px 20px;
    max-width: 1400px;
    margin: 0 auto;
}

.btn {
    display: inline-block;
    padding: 14px 32px;
    background: var(--primary);
    color: white;
    border-radius: 50px;
    text-decoration: none;
    font-size: 16px;
    font-weight: bold;
    transition: all 0.3s ease;
    border: none;
    cursor: pointer;
}

.btn:hover {
    background: var(--primary-dark);
    transform: translateY(-3px);
    box-shadow: 0 10px 20px rgba(64, 158, 255, 0.3);
}

.section-title {
    text-align: center;
    font-size: 36px;
    color: var(--dark);
    margin-bottom: 60px;
    position: relative;
}

.section-title::after {
    content: "";
    width: 80px;
    height: 4px;
    background: var(--primary);
    position: absolute;
    bottom: -15px;
    left: 50%;
    transform: translateX(-50%);
    border-radius: 2px;
}

/* 导航栏 */
nav {
    position: fixed;
    top: 0;
    width: 100%;
    background: rgba(255, 255, 255, 0.95);
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
    z-index: 999;
    padding: 15px 0;
}

.nav-container {
    max-width: 1400px;
    margin: 0 auto;
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 0 20px;
}

.logo {
    font-size: 24px;
    font-weight: bold;
    color: var(--primary);
    display: flex;
    align-items: center;
    gap: 10px;
}

.nav-menu {
    display: flex;
    list-style: none;
    gap: 40px;
}

.nav-menu a {
    text-decoration: none;
    color: var(--dark);
    font-size: 16px;
    font-weight: 500;
    transition: color 0.3s;
}

.nav-menu a:hover {
    color: var(--primary);
}

/* 🔥 全屏大图Banner（通栏背景） */
.banner {
    height: 100vh;
    /* 这里是全屏背景图，可替换 */
    background-image: url(https://picsum.photos/id/1/1920/1080);
    background-size: cover;
    background-position: center;
    background-repeat: no-repeat;
    background-attachment: fixed; /* 视差效果，更大气 */
    display: flex;
    align-items: center;
    position: relative;
    padding: 0 20px;
}

/* 背景遮罩，让文字更清晰 */
.banner::before {
    content: "";
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.4);
    z-index: 1;
}

.banner-container {
    max-width: 1400px;
    margin: 0 auto;
    display: flex;
    align-items: center;
    justify-content: space-between;
    position: relative;
    z-index: 2;
}

.banner-text {
    width: 100%;
    padding: 10px 20px;
}

.banner-text h1 {
    font-size: 60px;
    color: #fff;
    line-height: 1.2;
    margin-bottom: 25px;
    text-shadow: 0 2px 10px rgba(0,0,0,0.3);
}

.banner-text p {
    font-size: 20px;
    color: rgba(255,255,255,0.9);
    line-height: 1.6;
    margin-bottom: 40px;
    max-width: 700px;
    margin-right: auto;
}
/* 产品图片展示 */
.banner-right-img {
    max-width: 400px;
}

.banner-right-img img {    
    width: 100%;
    margin-left: 20px;
    border-radius: 15px;
}
/* 产品介绍 */
.intro {
    background: white;
}

.intro-content {
    display: flex;
    align-items: center;
    gap: 60px;
    flex-wrap: wrap;
}

.intro-img {
    flex: 1;
    min-width: 400px;
}

.intro-img img {
    width: 100%;
    border-radius: 15px;
}

.intro-text {
    flex: 1;
    min-width: 400px;
}

.intro-text h3 {
    font-size: 28px;
    margin-bottom: 20px;
    color: var(--dark);
}

.intro-text p {
    font-size: 16px;
    color: var(--gray);
    line-height: 1.8;
    margin-bottom: 15px;
}


/* 核心功能 */
.features {
    background: var(--light);
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 30px;
}

.feature-card {
    background: white;
    padding: 40px 30px;
    border-radius: 15px;
    text-align: center;
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.05);
    transition: transform 0.3s;
}

.feature-card:hover {
    transform: translateY(-10px);
}

.feature-card i {
    font-size: 48px;
    color: var(--primary);
    margin-bottom: 20px;
}

.feature-card h4 {
    font-size: 20px;
    margin-bottom: 15px;
    color: var(--dark);
}

.feature-card p {
    color: var(--gray);
    line-height: 1.6;
}

/* 使用场景 */
.scenes {
    background: white;
}

.scenes-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 25px;
}

.scene-item {
    text-align: center;
    padding: 20px;
}

.scene-item img {
    width: 300px;
    height: 169px;
    margin-bottom: 20px;
}

.scene-item h4 {
    font-size: 18px;
    margin-bottom: 10px;
    color: var(--dark);
}

.scene-item p {
    color: var(--gray);
}

/* 使用教程 */
.tutorial {
    background: var(--light);
}

.steps {
    display: flex;
    justify-content: center;
    flex-wrap: wrap;
    gap: 30px;
}

.step {
    width: 220px;
    text-align: center;
}

.step-num {
    width: 60px;
    height: 60px;
    background: var(--primary);
    color: white;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 24px;
    font-weight: bold;
    margin: 0 auto 20px;
}

.step h4 {
    font-size: 18px;
    margin-bottom: 10px;
}

/* 售后服务 */
.service {
    background: white;
}

.service-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 30px;
}

.service-card {
    padding: 30px;
    border-left: 4px solid var(--primary);
    background: var(--light);
    border-radius: 0 10px 10px 0;
}

.service-card h4 {
    font-size: 20px;
    margin-bottom: 15px;
    color: var(--dark);
}

.service-card p {
    color: var(--gray);
    line-height: 1.6;
}

/* 下载区域 */
.download {
    background: linear-gradient(135deg, #409eff 0%, #337ecc 100%);
    color: white;
    text-align: center;
    padding: 100px 20px;
}

.download h2 {
    font-size: 40px;
    margin-bottom: 20px;
}

.download p {
    font-size: 18px;
    margin-bottom: 40px;
    max-width: 700px;
    margin-left: auto;
    margin-right: auto;
}

.download .btn {
    background: white;
    color: var(--primary);
    font-size: 18px;
}

.download .btn:hover {
    background: #f0f7ff;
}

/* 页脚 */
footer {
    background: var(--dark);
    color: white;
    text-align: center;
    padding: 40px 20px;
}

footer p {
    color: #9ca3af;
}

/* 响应式 */
@media (max-width: 768px) {
    .nav-menu {
        display: none;
    }

    .banner-text h1 {
        font-size: 36px;
    }

    .section-title {
        font-size: 28px;
    }

    .intro-img, .intro-text {
        min-width: 100%;
    }
}


/* 视频列表 */
.video-page {
    padding: 80px 0;
}

.video-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
    gap: 30px;
}

.video-card {
    background: #fff;
    border-radius: 16px;
    overflow: hidden;
    box-shadow: 0 4px 12px rgba(0,0,0,0.06);
    transition: transform 0.3s, box-shadow 0.3s;
    cursor: pointer;
}

.video-card:hover {
    transform: translateY(-6px);
    box-shadow: 0 10px 25px rgba(0,0,0,0.1);
}

.video-cover {
    position: relative;
    width: 100%;
    height: 200px;
    background: #222;
}

.video-cover img {
    width: 100%;
    height: 100%;
    object-fit: cover;
}

.video-play {
    position: absolute;
    top: 50%; left: 50%;
    transform: translate(-50%, -50%);
    width: 60px; height: 60px;
    background: rgba(64,158,255,0.8);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    font-size: 22px;
}

.video-time {
    position: absolute;
    bottom: 10px; right: 10px;
    background: rgba(0,0,0,0.6);
    color: white;
    padding: 3px 8px;
    border-radius: 4px;
    font-size: 12px;
}

.video-info {
    padding: 20px;
}

.video-title {
    font-size: 17px;
    font-weight: 500;
    color: var(--dark);
    margin-bottom: 8px;
    line-height: 1.4;
}

.video-desc {
    font-size: 14px;
    color: var(--gray);
    line-height: 1.5;
}

        /* 顶部小banner */
.page-banner {
    height: 420px;
    background-image: url(https://picsum.photos/id/1076/1920/1080);
    background-size: cover;
    background-position: center;
    background-attachment: fixed;
    position: relative;
    display: flex;
    align-items: center;
    justify-content: center;
    text-align: center;
    color: white;
    margin-top: 70px;
}

.page-banner::before {
    content: '';
    position: absolute;
    left: 0; top: 0; width: 100%; height: 100%;
    background: rgba(0,0,0,0.55);
}

.page-banner .inner {
    position: relative; z-index: 2;
}

.page-banner h1 {
    font-size: 46px;
    margin-bottom: 15px;
}

.page-banner p {
    font-size: 18px;
    max-width: 700px;
    margin: 0 auto;
    opacity: 0.95;
}