body, html {
    height: 100vh;
    width: 100vw;
    margin: 0;
    background: url("../img/backgroundtb.webp") no-repeat;
    background-size: cover;
    padding: 0;
    display: flex;
    flex-direction: column;
}

@media (max-width: 900px) {
    body, html {
        background: url("../img/backgroundtb_phone.webp") no-repeat center center;
        background-size: cover;
        background-size: 100vw 100vh;
    }
}

body > section {
  width: 100vw;
}

.my_nav {
  height: 75px;
  display: flex;
  justify-content: space-between;
  background-color: rgba(0,0,0,0.25);
}

.my_nav > div {
  display: flex;
  justify-content: center;
  align-items: center;
  height: 100%;
}

.my_nav > div:nth-child(1), .my_nav > div:nth-child(3) {
  width: 30vw;
}

.my_nav > div:nth-child(2) {
  flex: 1;
}

.my_nav > div > a {
  height: 55%;
  width: 45px;
}

@media (max-width: 500px) {
  .my_nav > div:nth-child(1), .my_nav > div:nth-child(3) {
    width: 17vw;
  }
}

@media (max-width: 500px) {
  .my_nav > div > a {
    height: 45%;
    width: 35px;
  }
}

@media (max-width: 500px) {
  .my_nav > div > h4 {
    font-size: 16px;
  }
}