.koumoku1 {
    display: inline-block;
    position: relative;
    padding: .4em 1em;
    border-right: 27px solid #ff0000;
    background-color: hsl(0, 0%, 96%);
    color: #333333;
}

.koumoku1::before {
    position: absolute;
    bottom: 2px;
    right: -20px;
    z-index: -1;
    transform: rotate(5deg);
    width: 100%;
    height: 50%;
    background-color: #d0d0d0;
    content: "";
    filter: blur(4px);
}
.koumoku2 {
    display: inline-block;
    position: relative;
    padding: .4em 1em;
    border-right: 27px solid #0000ff;
    background-color: hsl(0, 0%, 96%);
    color: #333333;
}

.koumoku2::before {
    position: absolute;
    bottom: 2px;
    right: -20px;
    z-index: -1;
    transform: rotate(5deg);
    width: 100%;
    height: 50%;
    background-color: #d0d0d0;
    content: "";
    filter: blur(4px);
}