.c-seminar-btn {
    margin: 3rem 0;
}
.c-seminar-btn__body {
    font-size: 30px;
    color: #fff;
    background: #ff7644;
    box-shadow: 0 5px 0 #e46739;
    font-weight: 700;
    line-height: 1.5;
    position: relative;
    display: block;
    padding: 2rem 4rem;
    cursor: pointer;
    user-select: none;
    transition: all 0.3s;
    text-align: center;
    vertical-align: middle;
    text-decoration: none;
    letter-spacing: 0.1em;
    border-radius: 0.5rem;
}
.c-seminar-btn__body:hover {
    -webkit-transform: translate(0, 3px);
    color: #fff;
    background: #ff8d64;
    -webkit-box-shadow: 0 2px 0 #e46739;
}
@media screen and (max-width: 767px) {
    .c-seminar-btn__body {
        font-size: 16px;
        padding: 2rem;
    }
}

.c-seminar-btn span {
    font-size: 25px;
    position: absolute;
    top: -4rem;
    left: 0;
    right: 0;
    margin: auto;
    display: block;
    max-width: 85%;
    width: auto;
    padding: 0.4rem 2.2rem;
    color: #ff7644;
    border: 2px solid #ff7644;
    border-radius: 100vh;
    background: #fff;
    -webkit-box-shadow: 0 3px 3px rgba(0,0,0,0.2);
    box-shadow: 0 3px 3px rgba(0,0,0,0.2);
    white-space: nowrap;
}
@media screen and (max-width: 768px) {
    .c-seminar-btn span {
        font-size: 12px;
        top: -4rem;
        padding: 10px;
        max-width: 96%;
        width: auto;
    }
}

@media screen and (max-width: 350px) {
    .c-seminar-btn span {
        padding: 10px 2px;
    }
}

.c-seminar-btn span::after {
    position: absolute;
    left: calc(50% - 10px);
    content: "";
    bottom: -7px;
    border-width: 10px 10px 0 10px;
    border-style: solid;
    border-color: #fff transparent transparent transparent;
}
.c-seminar-btn span::before {
    bottom: -10px;
    border-width: 10px 10px 0 10px;
    border-style: solid;
    border-color: #ff7644 transparent transparent transparent;
}