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

  width: 100%;
  height: 3.5em;
  z-index: 99;
  position: fixed;
  box-shadow: 0 1px 3px 0 rgba(0, 0, 0, 0.5);
  background-color: #007dff; /*Internet Explorer*/
  background-color: var(--primary-color);
}

.navbar a {
  color: #f2f2f2; /*Internet Explorer*/
  color: var(--complementary-color-1);
}

.navbar .logo {
  display: flex;
  align-items: center;

  height: 100%;
  margin-left: 0.5rem;
}

.navbar .logo img {
  height: 75%;
  padding: 0.5em 0.5em;
}

.navbar ul {
  margin: 0;
  padding: 0;
  overflow: hidden;
  list-style: none;
  background-color: #007dff; /*Internet Explorer*/
  background-color: var(--primary-color);
}

.navbar li {
  /* Large screen */
  float: left;
}

.navbar li a {
  display: block;
  padding: 1em 1em;
  text-decoration: none;
}

.navbar li a:hover {
  color: #007dff; /*Internet Explorer*/
  color: var(--primary-color);
  background-color: #f2f2f2; /*Internet Explorer*/
  background-color: var(--complementary-color-1);
}

.navbar .menu {
  /* Large screen */
  max-height: none;
  flex-basis: auto;

  margin-right: 0.5rem;
}

.navbar .menu-checkbox {
  display: none;
}

.navbar .menu-hamburger-icon {
  /* Large screen */
  display: none;
}

/*--- Responsiveness ---*/

/*
- Small screens (e.g., cellphones) 576px < screen <= 768px
- Medium screens (e.g., tablets) 768px < screen <= 992px
- Large screens (e.g., computers) 992px < screen
*/
@media (max-width: 992px) {
  /* Cellphones and Tablets */
  .navbar li {
    float: none;
  }

  /*--- .menu ---*/
  .navbar .menu {
    max-height: 0;
    flex-basis: 100%; /*to force flex wrap*/
    transition: max-height 0.5s ease-in-out;

    margin-right: 0;
  }

  /* Menu style when menu-checkbox is checked */
  .navbar .menu-checkbox:checked ~ .menu {
    /*
        size_of_navbar_li_a * (number_of_navbar_li_a + 1 to be sure)
        size_of_navbar_li_a = 3em due to padding (see .navbar li a)
        */
    max-height: 18em;
  }
  /*--- .menu ---*/

  /*--- .menu-hamburger-icon ---*/
  .navbar .menu-hamburger-icon {
    cursor: pointer;
    display: inline-block;
    padding: 1rem 1rem;
    margin-right: 0.5rem;
    border: 1px solid #f2f2f2; /*Internet Explorer*/
    border: 1px solid var(--complementary-color-1);
    border-radius: 0.5rem;
  }

  /* meat */
  .navbar .menu-hamburger-icon .navicon {
    background: #f2f2f2; /*Internet Explorer*/
    background: var(--complementary-color-1);
    width: 1.25em;
    height: 0.2em;
    display: block;
    position: relative;
    transition: background 0.3s ease-out;
  }
  .navbar .menu-checkbox:checked ~ .menu-hamburger-icon .navicon {
    background: transparent;
  }

  /* top bun and bottom bun */
  .navbar .menu-hamburger-icon .navicon:before,
  .navbar .menu-hamburger-icon .navicon:after {
    background: #f2f2f2; /*Internet Explorer*/
    background: var(--complementary-color-1);
    content: "";
    width: 100%;
    height: 100%;
    display: block;
    position: absolute;
    transition: all 0.3s ease-out;
  }

  /* top bun only */
  .navbar .menu-hamburger-icon .navicon:before {
    top: -0.4em;
  }
  .navbar .menu-checkbox:checked ~ .menu-hamburger-icon .navicon:before {
    top: 0;
    transform: rotate(45deg);
  }

  /* bottom bun only */
  .navbar .menu-hamburger-icon .navicon:after {
    top: 0.4em;
  }
  .navbar .menu-checkbox:checked ~ .menu-hamburger-icon .navicon:after {
    top: 0;
    transform: rotate(-45deg);
  }
  /*--- .menu-hamburger-icon ---*/
}

/*--- Responsiveness ---*/