style1.css

* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
  font-family: sans-serif;
}
body {
  padding: 0 10px;
  background-image: url(img/pexels-pixabay-235985.jpg);
}
.regform {
  max-width: 500px;
  width: 100%;
  background: #c7d9e6;
  margin: 20px auto;
  padding: 30px;
  border-radius: 16px;
  box-shadow: 1px 1px 12px rgba(0, 0, 0, 0.4);
}

.regform input {
  margin-bottom: 20px;
  display: flex;
  align-items: center;
  width: 100$;
  border: none;
  border-bottom: 1px solid #fff;
  background: transparent;
  outline: none;
  height: 40px;
  color: #000;
  font-size: 16px;
}
.regform label {
  margin-bottom: 5px;
  display: flex;
  align-items: center;
  width: 200px;
  color: #1c0000;
  margin-right: 10px;
  font-size: 14px;
}
h1 {
  padding: 10px 0 20px;
  text-align: center;
}
button {
  border: none;
  outline: none;
  height: 40px;
  background: pink;
  width: 300px;
  color: #fff;
  font-size: 18px;
  border-radius: 20px;
}

button:hover {
  cursor: pointer;
  background: #9900e6;
  color: #000;
}