@font-face{
    font-family: cyberfont;
    src: url('../fonts/cyberfont.ttf');
}
#projects{
    padding: 0;
    height:750px;
    display:flex;
    align-items: top;
    justify-content: center;
    overflow: hidden;
    background-color: #262626;
    background-size: cover;
}

.projects-heading{
    padding: 100px 0 50px 0;
    font-family: cyberfont;
    font-weight: bold;
    color: white;
    text-align: center;
}



.projects-card{
    position: relative;
    background-color: white;
    box-shadow: 0 5px 10px rgba(0, 0, 0, .5);
    border-bottom-left-radius: 20px;
    border-bottom-right-radius: 20px;
    width: 300px;
    height:360px;
    overflow: hidden;
    display: flex;
    justify-content: center;
}

.projects-card-span{
    height: 80%;
    width: 100%;
    left: 0;
    /*background-image: url('../img/nav-bg.jpg');  第二个css想加载图片，前面要加 ‘../’ */
    position: absolute;
    transition: 1s;
    padding: 30px;
}

.span1{
    background-image: url('../img/web1.jpg');
    background-size: cover;
}

.span2{
    background-image: url('../img/web2.jpg');
    background-size: cover;
}

.span3{
    background-image: url('../img/web3.jpg');
    background-size: cover;
}
.projects-card-span:nth-child(1){
    z-index: 5;
    width: 25%;
    transition-delay: .2s;
}

.projects-card-span:nth-child(2){
    z-index: 4;
    width: 50%;
    transition-delay: .3s;
}

.projects-card-span:nth-child(3){
    z-index: 3;
    width: 75%;
    transition-delay: .4s;
}

.projects-card-span:nth-child(4){
    z-index: 2;
    width: 100%;
    transition-delay: .5s;
}

.projects-card:hover .projects-card-span{
    transform: translateY(-100%);
    transition: .3s;
}

.projects-card:hover .projects-card-span:nth-child(1){
    transition-delay: .5s;
}

.projects-card:hover .projects-card-span:nth-child(2){
    transition-delay: .4s;
}

.projects-card:hover .projects-card-span:nth-child(3){
    transition-delay: .3s;
}

.projects-card:hover .projects-card-span:nth-child(4){
    transition-delay: .2s;
}

.span-title{
    position: relative;
    text-align: center;
    z-index: 99;
    top: 8%;  
    font-size: 20px; 
    font-weight: bolder;
}

.project-button{
    position: absolute;
    bottom: 5%;
    padding: 7px 50px;
    display:block;
    border-radius: 5px;
    background: none;
    border: 1px solid #338033;
}

.project-button a{
    font-weight: bolder;
    font-family: 'Gill Sans', 'Gill Sans MT', Calibri, 'Trebuchet MS', sans-serif;
    text-transform: uppercase;
    color: #338033;
}

.project-button:hover{
    background-color: #338033;
    transition: .5s;
}

.project-button:hover a{
    color: white;
    text-decoration: none;
}