index.css

* main {
  box-sizing: border-box;
}

body {
  padding: 10px;
}

section {
  background-color: red;
  padding: 10px;
  border-radius: 5px;
  margin-bottom: 10px;
}

h1 {
  margin: 0;
  margin-bottom: 20px;
  color: white;
  text-shadow: 2px 2px 2px black;
  font-family: Arial;
  font-size: 30px;
}

input[type="text"] {
  height: 25px;
  padding-left: 5px;
  border-radius: 2px;
  border: none;
}

button {
  height: 25px;
  margin-top: 5px;
  background-color: white;
  border: none;
  border-radius: 2px;
}

.results {
  display: relative;
  margin-left: auto;
  margin-right: auto;
  text-align: center;
}

.col-1 {
  border-radius: 2px;
  width: 100%;
  margin-right: auto;
  margin-left: auto;
  margin-bottom: 5px;
}

@media only screen and (min-width: 450px){
  .col-1 {
    float: left;
    width: 50%;
  }

  .col-1::after, .col-1::before {
    display: table;
    content: '';
    clear: both;
  }
}

@media only screen and (min-width: 800px){
  .col-m-3 {
    float: left;
    width: 33.333%;
  }

  .col-m-3::after, .col-m-3::before {
    display: table;
    content: '';
    clear: both;
  }
}