signup.css

ul {
  width: 22em;
  display: flex;
  border: 1px solid transparent;
  justify-content: space-evenly;
  font-weight: 700;
}
li {
  list-style: none;
}
a {
  text-decoration: none;
  color: black;
}
nav {
  height: 60px;
  border: 1px solid black;
  justify-content: right;
  align-items: center;
  display: flex;
}

#signup-form-div {
  border: 1px solid transparent;
  width: 27%;
  margin: 20px auto;
  box-shadow: rgba(0, 0, 0, 0.35) 0px 5px 15px;
  padding: 2px 2px 13px 10px;
  text-align: center;
  border-radius: 15px;
}
form {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: space-evenly;
  height: 225px;
}
input {
  padding: 6px 12px;
}
input[type="submit"] {
  padding: 6px;
  width: 28%;
  background: teal;
  color: white;
  border: none;
  border-radius: 5px;
  cursor: pointer;
}