.box {
    position: relative;
    padding: 1rem;
    border-radius: 10px;
    background-color: #EEEEEE;
    border: 2px solid #333;
}

.box::before {
    position: absolute;
    top: 100%;
    left: 10%;
    height: 25px;
    width: 2px;
    transform: rotate(-20deg);
    background-color: #333;
    content: '';
}

.box p {
    color: #333;
    line-height: 1.5;
}