style.css

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

html {
  height: 100%;
}

body {
  height: 100%;
}

.heroDiv {
  height: 80vh;
}

.mobheroDiv {
  display: none;
}

.heroTxt {
  display: table;
}

.heroTxtDiv {
  display: table-cell;
  vertical-align: middle;
}

footer {
  height: 90px;
  background-color: black;
  color: white;
  display: table;
}

footer div {
  display: table-cell;
  vertical-align: middle;
}

.copy {
  float: left;
  margin-left: 50px;
}

.credit {
  float: right;
  margin-right: 50px;
}

@media screen and (max-width: 756px) {
  .heroDiv {
    display: none;
  }

  .mobheroDiv {
    display: block;
  }

  footer {
    text-align: center;
  }
  .copy {
    display: block;
    float: none;
    margin-left: 0px;
  }

  .credit {
    display: block;
    float: none;
    margin-right: 0px;
    margin-top: 5px;
  }
}