footer {
  background-color: black;
  color: white;
  padding: 40px 20px;
}

.footer-container {
  display: flex;
  justify-content: space-between;
}

.footer-section {
  display: flex;
  flex-direction: column;
  align-items: center;
  flex: 1;
  margin-right: 20px;
  font-family: "Montserrat";
}
.footer-section h3 {
  margin: 0 0 10px 20px;
  font-size: 1.2em;
  font-family: "Source Sans 3";
}
.footer-section .useful-links,
.footer-section ul {
  list-style-type: none;
  padding: 0;
}
.footer-section .useful-links li,
.footer-section ul li {
  margin-bottom: 5px;
  position: relative;
}
.footer-section .useful-links li a,
.footer-section ul li a {
  color: white;
  text-decoration: none;
  padding-bottom: 1px;
}
.footer-section .useful-links li a:hover,
.footer-section ul li a:hover {
  border-bottom: 1px solid white;
}

.social-nets {
  width: 100%;
  padding: 0;
  display: flex;
  flex-direction: row;
  justify-content: space-between;
}
.social-nets img {
  width: 50px;
}

.copyright {
  margin-top: 20px;
  text-align: center;
  font-family: "Montserrat";
}

@media screen and (max-width: 1024px) {
  .social-nets img {
    width: 40px;
  }
}
@media screen and (max-width: 820px) {
  .footer-container {
    flex-direction: column;
  }
  .footer-container p {
    width: 70%;
    text-align: center;
  }
  .footer-container h3 {
    margin: 20px;
    line-height: 0;
  }
  .footer-container .useful-links,
  .footer-container ul {
    text-align: center;
  }
  .social-nets {
    width: 60%;
  }
  .social-nets img {
    width: 60px;
  }
}
@media screen and (max-width: 500px) {
  .social-nets {
    width: 60%;
  }
  .social-nets img {
    width: 40px;
  }
}