.poster {
    text-align: center;
    font-family: Arial, Helvetica, sans-serif;
    position: relative;
    float: left;
    width: 570px;
    height:900px;
    margin: 0 30% 0;
}

.post-it {
    text-align: center;
    font-size: 9pt;
    position: relative;
    width: 100px;
    height: 130px;
    background-color: #FFFF99;
    padding-top: 5px;
    transform: rotate(12deg);
    display: inline-block;
    top: -230px;
    right: -185px;
}

del {
    position:relative;
    text-decoration:none;
    font-size: 25pt;
    font-weight: bold;
}
del::after {
    content:"";
    position:absolute;
    top:50%; left:0; width:100%; height:3px; 
    background:red;
    transform:skewY(15deg);
}

since {
    font-size: 25pt;
    font-weight: bold;
}

body {
    background-color: #FFFEF2;
}