style.css

html {
  height: 100vh;
  background: #d8af8d;
  background: repeating-linear-gradient(
    to right,
    rgb(229, 248, 240),
    rgb(229, 248, 240) 30px,
    rgb(214, 245, 232) 30px,
    rgb(214, 245, 232) 60px
  );
  background-size: cover;
}

body {
  padding: 2% 10%;
  font-family: "Segoe UI", Tahoma, Geneva, Verdana, sans-serif;
  color: rgb(83, 83, 83);
}

h2 {
  text-align: center;
  margin-bottom: 25px;
  font-variant: small-caps;
}

#add-array-number {
  display: flex;
  flex-direction: row;
  flex-wrap: wrap;
  justify-content: space-evenly;
}

.input-fields {
  width: 330px;
  height: 150px;
  margin: 0 auto 25px auto;
}

.inputs {
  width: 220px;
  height: 40px;
  display: block;
  margin: 20px auto 0 auto;
  text-align: center;
  font-family: "Segoe UI", Tahoma, Geneva, Verdana, sans-serif;
  font-size: 1rem;
  background: rgba(255, 255, 255, 0.8);
  color: rgb(83, 83, 83);
  border: none;
}

button {
  display: block;
  margin: 5px auto 20px auto;
  cursor: pointer;
  width: 145px;
  height: 40px;
  background: rgb(245, 252, 249);
  border: 2px rgb(89, 151, 125) solid;
  font-variant: small-caps;
  font-family: "Segoe UI", Tahoma, Geneva, Verdana, sans-serif;
  color: rgb(89, 151, 125);
  font-weight: 700;
}

fieldset {
  border: 2px rgb(89, 151, 125) solid;
  height: 150px;
}

.array {
  width: 330px;
  min-height: 20px;
  word-wrap: normal;
  font-weight: 600;
  font-size: 1.1rem;
  background: rgba(255, 255, 255, 0.8);
  color: rgb(89, 151, 125);
  display: block;
  margin: 25px auto 15px auto;
  padding: 15px 0;
  text-align: center;
}

#choose-method {
  display: block;
  margin-left: auto;
  margin-right: auto;
  width: 380px;
  min-height: 150px;
}

li {
  list-style: none;
  padding: 1%;
  word-wrap: normal;
}