body {
  background-color: #ffffff;
}
/* body * {
  outline: 1px solid red;
} */
nav {
  background-color: #233a4f;
}
.nav_btn,
.nav_btn:active,
.nav_btn:visited {
  font-size: 25px;
  color: #ffffff;

  margin-left: 10px;
  margin-right: 10px;

  padding: 5px;
}
.nav_btn:hover {
  color: #233a4f;
  background-color: #ffffff;
}
#logo {
  width: 5%;
  margin: 10px;
}
#menu_btn {
  margin-right: 10px;
  background-color: #ffffff;
  outline: none !important;
}

/*.bg_img {
  background-image: url('imgs/test_img.svg');
  background-size: 100%;
  background-repeat: no-repeat;
}*/

#intro_img {
  width: 100%;
}
#topology_img {
  width: 100%;
}
#console_img {
  width: 100%;
}

.card {
  width: 500px;

  margin: 50px;
  padding: 10px;

  border-color: #ffffff;
  box-shadow: #ffffff;
  border-width: 5px;
  border-radius: 0%;
}
.card-title {
  color: #416f9a;
  font-weight: bold;
}
.card_text {
  font-family: Arial;
  font-size: 30px;
}

#footer {
  background-color: #233a4f;
  color: #ffffff;
  padding: 20px;
}

.row {
  margin: 0px;
}
.space {
  height: 100px;
}

.coloured {
  color: #416f9a;
}
.coloured2 {
  color: #233a4f;
}
.text_big {
  font-family: Arial;
  font-size: 75px;
}
.text_mdl {
  font-family: Arial;
  font-size: 40px;
}

/*back to top button*/

html {
  scroll-behavior: smooth;
}

.back-to-top {
  position: fixed;
  bottom: 2rem;
  right: 2rem;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  border-radius: 0.5rem;
  padding-left: 0.75rem;
  padding-right: 0.75rem;
  text-decoration: none;
  transition: 0.2s ease-out;

  background-color: rgba(65, 111, 154, 0.5);
}

.back-to-top span {
  color: #fff;
  font-size: 3rem;
  transition: 0.2s ease-out;
}

.back-to-top:hover {
  background-color: rgb(35, 58, 79, 0.9);
}
.back-to-top:hover span {
  transform: translateY(-4px);
}