style.css

html {
  box-sizing: border-box;
}

* {
  box-sizing: inherit;
}

body {
  margin: 0;
  font-family: sans-serif;
}

ul {
  list-style-type: none;
  margin: 0;
  padding: 0;
}

.header {
  background-color: #1d9345;
  padding: 0.5em auto;
  display: flex;
  justify-content: space-around;
  align-items: center;
}

.header__logo {
  color: #fff;
  font-size: 1.5rem;
}

.header__search {
  border: none;
  border-radius: 1em;
  padding: 0.5em 1em;
}

.main {
  margin: 1em auto;
  border: 1px solid lightgray;
  padding: 1em;
  width: 80%;
  max-width: 500px;
}

.main__input {
  border-radius: 1em;
  border: 1px solid black;
  font-size: 1.25rem;
  max-width: 80%;
  outline: none;
  padding: 0.25em 1em;
}

.main__submit {
  color: white;
  background-color: black;
  cursor: pointer;
  margin: 0.2em;
  font-size: 1.2rem;
  border-radius: 1em;
  padding: 0.25em 1em;
}

.main__items {
  border: 1px solid gray;
  border-radius: 1em;
  min-height: 65px;
}

.main__item {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 0.25em 1em;
  min-height: 65px;
}

.main__item + .main__item {
  border-top: 1px solid lightgray;
}

.main__delete {
  color: white;
  background-color: rgb(234, 69, 69);
  border: none;
  cursor: pointer;
  width: 30px;
  height: 30px;
  border-radius: 50%;
  font-weight: bold;
}

/* On screens that are 380px or less */
@media screen and (max-width: 380px) {
  .main__form {
    display: flex;
    flex-direction: column;
    justify-content: space-evenly;
    align-items: center;
  }

  .header__logo {
    font-size: 1rem;
  }
}

@media (prefers-color-scheme: dark) {
  body {
    color: white;
    background-color: #212221;
  }
}