.site-header {
  display: flex;
  align-items: center;
  gap: 16px;
  padding-top: 24px;
  padding-bottom: 16px;
}

.main-navigation {
  display: block;
  width: 100%;
}

.main-navigation ul {
  display: none;
  list-style: none;
  gap: 20px;
}

.main-navigation ul ul {
  box-shadow: 0 3px 3px rgba(0, 0, 0, 0.2);
  float: left;
  position: absolute;
  top: 100%;
  left: -999em;
}

.main-navigation ul ul ul {
  left: -999em;
  top: 0;
}

.main-navigation ul ul li:hover > ul,
.main-navigation ul ul li.focus > ul {
  display: block;
  left: auto;
}

.main-navigation ul ul a {
  width: 200px;
}

.main-navigation ul li:hover > ul,
.main-navigation ul li.focus > ul {
  left: auto;
}

.main-navigation li {
  position: relative;
}

.main-navigation a {
  display: block;
  text-decoration: none;
  color: var(--foundation-white);
}

.main-navigation a:hover {
  color: var(--foundation-blue);
}

/* Small menu. */
.menu-toggle,
.main-navigation.toggled ul {
  display: block;
  text-align: end;
  color: var(--foundation-white);
  background-color: transparent;
  border: none;
  margin-left: auto;
  font-size: 1.5rem;
}

.head-register-btn {
  display: none;
}

@media screen and (min-width: 768px) {
  .menu-toggle {
    display: none;
  }

  .head-register-btn {
    font-family: "IBM Plex Sans Thai", sans-serif;
    display: block;
    color: var(--foundation-black);
    background-color: var(--foundation-white);
    border-radius: 64px;
    border: none;
    padding: 4px 8px;
    text-decoration: none;
  }

  .main-navigation ul {
    display: flex;
    justify-content: flex-end;
    font-size: 1.125rem;
    font-weight: 500;
    gap: 40px;
  }

  .head-register-btn {
    font-size: 1.125rem;
    padding: 4px 40px;
  }
}