*{
    margin: 0;
    padding: 0;
    font-family: 'Poppins', sans-serif;
}
.header{
    min-height: 100vh;
    width: 100%;
    background-image: linear-gradient(rgba(4,9,30,0.7),rgba(4,9,30,0.7)),url(images/GiF.gif);
    background-position: center;
    background-size: cover;
    position: relative;
} 
nav{
    display: flex;
    padding: 2% 6%;
    justify-content: space-between;
    align-items: center;

}
nav img{
    width: 150px;
}
.nav-links{
    flex: 1;
    text-align: right;
}
.nav-links ul li{
    list-style: none;
    display: inline-block;
    padding: 8px 12px;
    position: relative;
}
.nav-links ul li a{
    color: #fff;
    text-decoration: none;
    font-size: 16px;
}
.nav-links ul li::after{
    content: '';
    width: 0%;
    height: 2px;
    background: #08b4ce;
    display: block;
    margin: auto;
    transition: 0.5s;

}
.nav-links ul li:hover::after{
    width: 100%;
}
.text-box{
    width: 90%;
    color: #fff;
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%,-50%);
    text-align: center; 
}
.text-box h1{
    font-size: 62px;
}
.text-box p{
    margin: 10px 0 40px;
    font-size: 14px;
    color: #fff;
}
.hero-btn{
    display: inline-block;
    text-decoration: none;
    color: #fff;
    border: 1px solid #fff;
    padding: 12px 34px;
    font-size: 13px;
    background: transparent;
    position: relative;
    cursor: pointer;
}
.hero-btn:hover{
    border: 1px solid #08b4ce;
    background: #08b4ce;
    transition: 1s;
}

nav .fa{
    display: none;
}

@media(max-width: 700px){
    .text-box h1{
        font-size: 25px;
    }
    .nav-links ul li{
        display: block;
    }
    .nav-links{
        position: fixed;
        background: #08b4ce;
        height: 100vh;
        width: 200px;
        top: 0;
        right: -200px;
        text-align: left;
        z-index: 2; 
        transition: 1s;
    }
    nav .fa{
        display: block;
        color: #fff;
        margin: 10px;
        font-size: 22px;
        cursor: pointer;
    }
    .nav-links ul{
        padding: 30px;
    }
}

/*----- course -----*/

.course{
    width: 80%;
    margin: auto;
    text-align: center;
    padding-top: 100px;
}
h1{
    font-size: 33px;
    font-weight: 600;
}

p{
    color: #777;
    font-size: 14px;
    font-weight: 300;
    line-height: 22px;
    padding: 10px;
}

.row{
    display: flex;
    justify-content: space-between;
}
.course-col{
    flex-basis: 31%;
    background: rgb(219, 219, 219);
    border-radius: 10px;
    margin-bottom: 5%;
    padding: 20px 12px;
    box-sizing: border-box;
}
h3{
    text-align: center;
    font-weight: 600;
    margin: 10px 0;
    transition: 0.5s;
}
.course-col:hover{
    box-shadow: 0 0 20px 0px rgba(0,0,0,0.2);
}
@media(max-width: 700px){
    .row{
        flex-direction: column;
    }
}

/*------- 应用场景 ----*/

.应用场景{
    width: 80%;
    margin: auto;
    text-align: center;
    padding-top: 50px;
}
.应用场景-col{
    flex-basis: 32%;
    border-radius: 10px;
    margin-bottom: 30px;
    position: relative;
    overflow: hidden;
}
.应用场景-col img{
    width: 100%;
    display: block;
}
.layer{
    background: transparent;
    height: 100%;
    width: 100%;
    position: absolute;
    top: 0;
    left: 0;
    transition: 0.5s;
}
.layer:hover{
    background: rgba(0, 195, 254, 0.7);
}
.layer h3{
    width: 100%;
    font-weight: 500;
    color: #fff;
    font-size: 26px;
    bottom: 0;
    left: 50%;
    transform: translateX(-50%);
    position: absolute;
    opacity: 0;
    transition: 0.5s;
}
.layer:hover h3{
    bottom: 49%;
    opacity: 1;
}

/*--------- 我们的环境 ---------*/

.我们的环境{
    width: 80%;
    margin: auto;
    text-align: center;
    padding-top: 100px;
}
.我们的环境-col{
    flex-basis: 31%;
    border-radius: 10px;
    margin-bottom: 5%;
    text-align: left;
}
.我们的环境-col img{
    width: 100%;
    border-radius: 10px;
}

.我们的环境-col p{
    padding: 0;
}
.我们的环境-col h3{
    margin-top: 16px;
    margin-bottom: 15px;
    text-align: left;

}

/*------ testimonials ------*/

.testimonials{
    width: 80%;
    margin: auto;
    padding-top: 100px;
    text-align: center;
}
.testimonial-col{
    flex-basis: 27.5%;
    border-radius: 10px;
    margin-bottom: 3%;
    background: #08b4ce;
    padding: 25px;
    cursor: pointer;
    display: flex;
}
.testimonial-col img{
    height: 80px;x
    margin-left: 5px;
    margin-right: 30px;
    border-radius: 50%;
}
.testimonial-col h3{
    margin-top: 15px;
    text-align: center;
    color: hsl(0, 0%, 100%);
}
.testimonial-col p{
    padding: 0;
    color: hsl(0, 0%, 100%);
}
@media(max-width: 700px){
    .testimonial-col img{
        margin-left: 0px;
        margin-right: 15px;
    }
}

/*------ Call to action ------*/

.cta{
    margin: 100px auto;
    width: 80%;
    background-image: linear-gradient(rgba(40, 40, 40, 0.7),rgba(40,40,40,0.7)),url(images/Cooperation.jpg);
    background-position: center;
    background-size: cover;
    border-radius: 10px;
    text-align: center;
    padding: 100px 0;
}

.cta h1{
    color: #fff;
    margin-bottom: 40px;
    padding: 0;
}

@media(max-width: 700px){
    .cta h1{
        font-size: 24px;
    }
}

/*------ footer ------*/

.footer{
    width: 100%;
    text-align: center;
    padding: 30px 0;
}

.footer h4{
    margin-bottom: 25px;
    margin-top: 20px;
    font-weight: 600;
}

/*----------- about us page --------*/

.sub-header{
    height: 50vh;
    width: 100%;
    background-image: linear-gradient(rgba(4,9,30,0.7),rgba(4,9,30,0.7)),url(images/Background.jpg);
    background-position: center;
    background-size: cover;
    text-align: center;
    color: #fff;
}
.sub-header h1{
    margin-top: 100px;
}
.about-us{
    width: 80%;
    margin: auto;
    padding-top: 80px;
    padding-bottom: 50px;
}
.about-col{
    flex-basis: 48%;
    padding: 30px 2px;
}
.about-col img{
    width: 100%;
} 
.about-col h1{
    padding-top: 0;
}
.about-col p{
    padding: 15px 0 25px;
}
.blue-btn{
    border: 1px solid #08b4ce;
    background: transparent;
    color: #08b4ce;
}
.blue-btn:hover{
    color: #fff;
}

@media(max-width: 700px){
    .about-us h1{
        font-size: 23px;
    }
}

/*---------- project-content ------------*/

.project-content{
    width: 80%;
    margin: auto;
    padding: 60px 0;
}
.project-left video{
    width: 100%;
}
.project-left h2{
    color: #222;
    font-weight: 600;
    margin: 30px 0;
}
.project-left p{ 
    color: #999;
    padding: 0;
}

.comment-box{
    border: 1px solid #ccc;
    margin: 50px 0;
    padding: 10px 20px;
}
.comment-box h3{
    text-align: left;
}
.comment-form input, .comment-form textarea{
    width: 100%;
    padding: 10px;
    margin: 15px 0;
    box-sizing: border-box;
    border: none;
    outline: none;
    background: #f0f0f0;
}

.comment-form button{
    margin: 10px 0;
}

@media(max-width:700px){
    .sub-header h1{
        font-size: 24px;
    }
    .project-left h2{
        font-size: 20px;
    }
}
/* ---------contact us page ----------*/

.location{
    width: 70%;
    margin: auto;
    padding: 100px 0;
}
.location #container{
    width: 100%;
}
.contact-us{
    width: 80%;
    margin: auto;
}

.contact-col{
    flex-basis: 15%;
    margin: auto;
}
.contact-col div{
    display: flex;
    align-items: center;
    margin-bottom: 40px;
}

.contact-col div .fa{
    font-size: 30px;
    color: #08b4ce;
    margin-right: 30px;
}
.contact-col div p{
    padding: 0;
}
.contact-col div h5{
    font-size: 18px;
    margin-bottom: 10px;
    color: #08b4ce;
    font-weight: 400;
}

/*-------product---------*/

.product{
    width: 80%;
    margin: auto;
    padding-top: 80px;
    padding-bottom: 50px;
}
.product-col{
    flex-basis: 48%;
    padding: 30px 2px;
}
.product-col img{
    width: 100%;
} 
.product-col h1{
    padding-top: 0;
}
.product-col p{
    padding: 15px 0 25px;
}
.blue-btn{
    border: 1px solid #08b4ce;
    background: transparent;
    color: #08b4ce;
}
.blue-btn:hover{
    color: #fff;
}

@media(max-width: 700px){
    .product-col h1{
        font-size: 28px;
    }
}