style.css

* {
  padding: 0;
  margin: 0;
  box-sizing: border-box;
}

html {
  font-size: 62.5%;
}

body {
  font-family: "Poppins", sans-serif;
  background: #f3f3f3;
  display: flex;
  justify-content: center;
  align-items: center;
  flex-direction: column;
  min-height: 100vh;
}

label,
input,
small,
button {
  display: block;
}

h2 {
  text-align: center;
  margin-bottom: 1.5rem;
  font-size: 2.6rem;
  font-weight: bold;
}

.container {
  width: 400px;
  background: #d7d7d7;
  border-radius: 10px;
}

.form {
  padding: 4rem 3rem;
}

.form-control {
  margin-bottom: 1.2rem;
  padding-bottom: 2rem;
  font-size: 1.4rem;
  position: relative;
}

.form-control label {
  color: #4e4e4e;
  margin-bottom: 0.8rem;
}

.form-control input {
  font-size: 1.2rem;
  padding: 0.8rem;
  border-radius: 5px;
  border: 2px solid #f0f0f0;
  width: 100%;
}

.form-control small {
  position: absolute;
  left: 0;
  bottom: 0;
  font-size: 1.3rem;
  visibility: hidden;
}

.form-control input:focus {
  outline: none;
  border-color: #4e4e4e;
}
.form-control.success input {
  outline: none;
  border-color: #0f8000;
}
.form-control.error input {
  outline: none;
  border-color: #bb0101;
}

.form-control.error small {
  visibility: visible;
  color: #bb0101;
}

.form-control i {
  position: absolute;
  bottom: 30px;
  right: 10px;
  color: #bababa;
  cursor: pointer;
}

.form-control i:hover {
  color: #4e4e4e;
}

button {
  width: 100%;
  padding: 1.2rem;
  cursor: pointer;
  background: #0f8000;
  font-size: 1.6rem;
  font-family: inherit;
  font-weight: 600;
  color: #f3f3f3;
  border: none;
  border-radius: 5px;
  margin-top: 1.2rem;
}