* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}
body {
  font-family: inherit;
  line-height: 1.5;
  background-color: green;
}

.parent{
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    margin:  auto;
    text-align: center;
    max-width: 450px;
    background-color: orangered;
    border: 2px solid;
    padding: 20px;
    border-top: none;
}

.parent div {
 background-color: #000000;
 color:wheat;
 max-width: 100px;
padding: 20px;
margin: 7px;
font-size: 20px;
border-radius: 50%;
cursor: pointer;
}

h2 {
    text-align: center;
    display: block;
    margin-top:100px;
    font-size: 2.5rem;
}

.input-div{
    margin-top: 30px;
    text-align: center;
  
}

.input-div .input-text{
    width: 450px;
    height: 55px;
    font-size: 36px;
    border-bottom: 2px solid black;
    border-right: 2px solid black;
    color:black;
    text-align: start; 
    padding: 30px;
    background-color: #c5c1c1;
}

@media screen and (max-width: 430px) {
    .input-div .input-text{
        width: 100%;
    }

    .input-div {
        max-width: 100%;
    }
}