سلام کد کاپ

styles.css

*{
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family:'Outfit', sans-serif;
}

.container{
    background-color: rgb(27,29,46);
    height: 100vh;
}

.envelope{
    position: relative;
    width: 300px;
    height: 200px;
    border-radius: 0px 0px 10px 10px;
    margin: 0 auto;
    top: 300px;
    background-color: rgb(90, 240, 182);
}

.cover{
    position: absolute;
    height: 0px;
    width: 0px;
}

.cover.top{
    border-left: 150px solid transparent;
    border-right: 150px solid transparent;
    border-bottom: 100px solid transparent;
    border-top: 100px solid rgb(90, 240, 182);
    transform-origin: top;
}

.cover.bottom.right{
    border-left: 150px solid transparent;
    border-right: 150px solid rgb(90,209,151);
    border-bottom: 100px solid rgb(90,209,151);
    border-top: 100px solid transparent;
    border-radius: 0px 0px 10px 10px;
    z-index: 5;
}

.cover.left{
    border-left: 150px solid rgb(90, 225, 167);
    border-right: 150px solid transparent;
    border-bottom: 100px solid transparent;
    border-top: 100px solid transparent;
    border-bottom-left-radius: 10px;
    z-index: 5;
}

.putIn{
    transition: transform 0.7s ease;
    transform: translate(0px, 0px);
}

.pullOut{
    transition: transform 0.7s ease 0.5s;
    transform: translate(0px, -200px);;
}

.letter{
    background-color: rgb(252, 228, 94);
    width: 95%;
    height: 100%;
    margin:0 auto;
    padding: 10px;
    text-align: center;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: 10px;
    font-size: 25px;
}

.open{
    transform: rotateX(180deg);
    transition: transform 0.4s ease;
    z-index: 0;
}

.close{
    transform:rotateX(0deg);
    z-index:1;
    transition: transform 0.4s ease 0.7s,z-index 0.1s ease 0.6s;
}