header {
  border-bottom: 1px solid var(--primary-dark-color);
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 1rem 4.5rem 0.8125rem 2.5rem;
}

header h1 {
  display: flex;
  align-items: baseline;
  gap: 0.25rem;
  margin: 0;
  .h1-subtitle {
    font-family: "Noto Sans JP", sans-serif;
    font-size: 1rem;
    font-weight: 500;
    color: var(--primary-dark-color);
    transform: translateY(-0.5rem);
  }
}

.header-button-group {
  display: flex;
  gap: 1.25rem;
}

.hamburger-button,
.hamburger-menu-list {
  display: none;
}

@media (max-width: 850px) {
  .h1-subtitle {
    display: none;
  }
}
@media (max-width: 768px) {
  header {
    position: relative;
    padding: 1rem 2rem 0.8125rem 2rem;
  }
  .header-button-group {
    display: none;
  }
  .hamburger-button {
    display: block;
    cursor: pointer;
    margin-left: 1rem;
  }
  .hamburger-menu-list {
    position: absolute;
    right: 0;
    transform: translateY(90%);
    display: flex;
    flex-direction: column;
    z-index: 1;
    button {
      border-radius: 0;
      width: 100%;
    }
  }
}