message: exchange page: update styles
diff: .section {
  display: flex;
  justify-content: space-between;
  - flex-wrap: wrap;
  +}
  +.blockVideo {
  + flex-basis: 58%;
  + iframe {
  + width: 100%;
  + height: 355px;
  + }
  }
  .block {
  - width: 400px;
  + flex-basis: 37%;
  }
  .error {
  padding: 0;
  }
  -@include media-mobile {
  +@include media-tablet {
  + .blockVideo {
  + flex-basis: 50%;
  + }
  + .block {
  + flex-basis: 45%;
  + }
  + .button {
  + font-size: 12px;
  + }
  +}
  +@media all and (min-width: 320px) and (max-width: 830px) {
  .section {
  margin-top: 20px;
  justify-content: center;
  + flex-direction: column-reverse;
  + max-width: 400px;
  + margin: auto;
  + }
  + .button {
  + font-size: 12px;
  + }
  + .block {
  + margin-bottom: 80px;
  + margin-top: 60px;
  }
  -
  - .blockVideo {
  - display: none;
  }
  +@media all and (min-width: 320px) and (max-width: 400px) {
  .button {
  - font-size: 12px;
  + font-size: 9px;
  }
  }
  