header.css

* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

.navbar {
  display: flex;
  position: relative;
  flex-wrap: wrap;
  justify-content: space-between;
  align-items: center;
  background-color: #d9d9d9;
  color: #031e36;
  width:100%;
  padding-left: 20px;
}

.navbar-links {
  height: 100%;
}

.navbar-links ul {
  float: right;
  display: flex;
  font-size: 1.2rem;
  margin: 0 30px;
  padding: 0;
}

.navbar-links li {
  list-style: none;
  padding: 0;
}

.navbar-links li a {
  font-size: 20px;
  display: block;
  text-decoration: none;
  color:#000000;
  padding: 1.5rem;
}

.navbar-links li:hover {
  border-bottom: 5px solid #4386f4;
}

.toggle-button {
  position: absolute;
  top: .75rem;
  right: 1rem;
  display: none;
  flex-direction: column;
  justify-content: space-between;
  width: 30px;
  height: 21px;
}

.toggle-button .bar {
  height: 3px;
  width: 100%;
  background-color: #031e36;
  border-radius: 10px;
}   

@media (max-width: 470px){
  .brand-title img{
    padding-left: 0px;
    margin-left: 0px;
    width:40%;
  }

  .toggle-button {
    margin-right: 1px;
    display: flex;
  }
 

  .navbar{
    width:100%;
  }
  
  .navbar-links ul {
    width: 80%;
    flex-direction: column;
  }
}

@media (max-width: 904px){
  .navbar {
    padding-top: 10px;
    padding-bottom: 5px;
    flex-direction: column;
    align-items: flex-start;
  }

.toggle-button {
    margin-top: 5px;
    display: flex;
  }
 
.navbar-links {
    display: none;
    width: 100%;
  }

.navbar-links ul {
    width: 100%;
    flex-direction: column;
  }

.navbar-links ul li {
    text-align: center;
    justify-content: space-between;
  }

.navbar-links ul li a {
    padding: .5rem 1rem;
  }

  .navbar-links.active {
    display: flex;
  }
}