header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  background-color: var(--background-color);
  position: sticky;
  width: 100%;
  z-index: 1000;
  box-shadow: var(--box-shadow);
  padding: 1em 2em;
  box-sizing: border-box;
}

.logo {
  color: var(--primary-color);
  font-size: 2.5em;
  text-decoration: none;
  font-family: var(--font-family1);
}

.menu-toggle {
  display: none;
  cursor: pointer;
}

.menu-toggle .bar {
  display: block;
  width: 2em;
  height: 0.2em;
  margin: 0.3em 0;
  transition: all 0.3s ease;
  background-color: var(--primary-color);
}

.navbar {
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.menu {
  display: flex;
  justify-content: space-between;
  align-items: center;
  list-style: none;
}

.menu li {
  margin: 0 1em;
}

.menu a {
  color: var(--text-color);
  text-decoration: none;
  font-size: 1.2em;
  font-family: var(--font-family1);
  transition: all 0.3s ease;
}

.menu a:hover {
  color: var(--primary-color);
}

#language-selector {
  display: flex;
  align-items: center;
}

#language {
  padding: 0.5em;
  border: none;
  border-radius: var(--border-radius);
  margin: 0 1em;
  font-family: var(--font-family1);
  font-size: 1em;
  cursor: pointer;
}

/* Media Query */
@media (max-width: 768px) {
  .menu-toggle {
    display: block;
  }

  .navbar {
    display: none;
    flex-direction: column;
    width: 100%;
    position: absolute;
    top: 100%;
    left: 0;
    background-color: var(--background-color);
    box-shadow: var(--box-shadow);
  }

  .navbar.active {
    display: flex;
  }

  .menu {
    flex-direction: column;
    padding: 2em;
    text-align: center;
  }

  .menu li {
    margin: 1em 0;
  }
}