styles.css

html {
  height: 100%;
}
body {
  height: 100%;
  background-color: rgb(31, 30, 30);
}

.title {
  color: white;
  font-family: system-ui;
  font-size: 3rem;
  margin: 10%;
  text-align: center;
}
.container {
  background-color: rgb(51, 51, 51);
  display: flex;
  align-items: center;
  justify-content: space-around;
  margin: auto;
  height: 35%;
  width: 75%;
  border: 1px solid rgba(90, 89, 89, 0.644);
  padding: 10px;
  box-shadow: -5px -5px 50px black;
}
.center {
  margin-left: auto;
  margin-top: auto;
}

.converter {
  justify-content: center;
  display: flex;
  align-items: center;
  justify-content: space-around;
  margin: 50px;
  height: auto;
  width: 80%;
}

.calc_input {
  display: block;
}
.first_currency_select {
    height: 35px;
    border-radius: 3px
}
.second_currency_select {
  height: 35px;
  border-radius: 3px
}
.currency_input {
  height: 35px;
  border-radius: 5px;
}
.currency_output {
    height: 35px;
    border-radius: 5px;
  }
.convert {
  background-color: rgb(194, 194, 194);
  height: 50px;
  width: auto;
  padding-left: 30px;
  padding-right: 30px;
  padding-bottom: 5px;
  border: 1px solid #222222;
  border-radius: 5px;
  font-size: 32px;
  font-weight: 600;
  line-height: 20px;
}
.convert:hover {
  background-color: gray;
}