.container {
  width: 90%;
  margin-left: auto;
  margin-right: auto;
}
section:nth-of-type(1) {
  /* Home section */
  margin-top: var(--header-height);
}
section:last-of-type {
  /* Contact section */
  margin-bottom: calc(var(--header-height) - 10px);
}

.section_title {
  margin-top: calc(70px - var(--header-height) - 10px);
  margin-bottom: 20px;
  padding-top: calc(var(--header-height) + 10px);
  color: var(--blue-main-color);
}

.section_title::after {
  content: '';
  display: block;
  margin: 2px 0 0 1px;
  height: 3px;
  background-color: var(--blue-main-color);
}

@media (min-width: 680px) {
  .section_title {
    font: 700 28px/32px Helvetica, Arial, sans-serif;
  }
  .section_title::after {
    width: 30px;
  }
}
@media screen and (max-width: 680px) {
  .section_title {
    font: 700 24px/28px Helvetica, Arial, sans-serif;
  }
  .section_title::after {
    width: 24px;
  }
}