* {
    box-sizing: border-box;
}
 
body {
    margin: 0;
}
 
.container {
    width: 100%;
    min-height: 100vh;
    background-color: rgb(136, 226, 233);
    display: flex;
    flex-direction: column;
}
 
header {
    background-color: #0b919b;
    color: white;
    text-align: center;
    padding: 20px;
}
 
main {
    flex: 1;
    display: flex;
    justify-content: center;
    align-items: center;
}
 
.gallery {
    display: flex;
    flex-wrap: wrap;
    gap: 20px;
    justify-content: center;
}
 
.box {
    position: relative;
    width: 300px;
    height: 300px;
    overflow: hidden;
    border: 15px solid rgb(255, 255, 255);
    border-radius: 15px;
}
 
.box img {
    position: absolute;
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: opacity 0.5s ease;
}
 
.box .img2 {
    opacity: 0;
}
 
.box:hover .img1 {
    opacity: 0;
}
 
.box:hover .img2 {
    opacity: 1;
}
 
footer {
   background-color: #0b919b;
    color: white;
    text-align: center;
    padding: 15px;
}