body {
    font-family: Arial, sans-serif;
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    margin: 0;
    background-color: #202020;
}
.calendar {
    display: grid;
    grid-template-columns: repeat(6, 1fr);
    gap: 10px;
    width: 70%;
}
.box {
    position: relative;
    width: 100%;
    padding-top: 100%;
    background-color: #ccc;
    cursor: pointer;
    overflow: hidden;
    border-radius: 10px;
}
.box .content {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    display: flex;
    justify-content: center;
    align-items: center;
    font-size: 1.5rem;
    font-weight: bold;
    color: white;
    background: rgb(255,255,255);
    background: linear-gradient(90deg, rgba(255,255,255,1) 0%, rgba(30,136,242,1) 0%, rgba(9,41,121,1) 51%);
    transition: opacity 0.3s;
}
.box img {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    object-fit: cover;
    display: none;
}
.box.open .content {
    display: none;
}
.box.open img {
    display: block;
}

@media only screen and (max-width: 600px) {
    .calendar{
        margin: 2% auto;
        display: grid;
        grid-template-columns: repeat(2, 1fr);
        width: 90%;
    }
}