.blasting_flex {
  display: flex;
  flex-wrap: column;
  margin: 50px auto;
  align-items: center;
}

.blas_img {
  height: 25px;
  width: auto;
  margin: 5px auto;
}

.blas_flex {
    margin: 30px 0px;
}

.blasting_flex h4 {
  font-size: 1.4em;
  margin: 15px 0px;
  background-color: #f5f5f5;
  padding: 20px;
}

.blas_left {
   margin-right: 30px;
}

.rokkakkei {
  width: 100%;
}

 .contact_button {
  background-color: #fff;
  border: solid 1px black;
  color: #2f4f4f;
  padding: 10px 30px;
  text-decoration: none;
  font-size: 1em;
}
.contact_button:hover {
  color: black;
  background-color: #f5f5f5;
}

@media screen and (max-width: 450px) {
  blasting_flex: 
  display: block;
  
}