* {
    margin: 0;
    padding: 0;
}

html, body {
    width: 100%;
    height: 100%;
    display: flex;
    flex-direction: column;
    align-items: center;
}

h1 {
    margin: 20px;
}

.main {
    width: 1260px;
    height: 1200px;
    display: flex;
    flex-wrap: wrap;
    justify-content: space-between;
    align-items: flex-start;
}

.box {
    width: 200px;
}

#box1 {
    background: url('../images/gray-1.jpg') no-repeat;
    background-size: 100%;
}

#box2 {
    background: url('../images/gray-2.jpg') no-repeat;
    background-size: 100%;
}

#box3 {
    background: url('../images/gray-3.jpg') no-repeat;
    background-size: 100%;
}

#box4 {
    background: url('../images/gray-4.jpg') no-repeat;
    background-size: 100%;
}

#box5 {
    background: url('../images/gray-5.jpg') no-repeat;
    background-size: 100%;
}

#box6 {
    background: url('../images/gray-6.jpg') no-repeat;
    background-size: 100%;
}

.pic {
    width: 200px;
    opacity: 0;
    transition: all 3s linear;
	cursor:pointer;
}

.show {
    opacity: 1;
}