style.css

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

:root {
  --main-color: #161a1d;
  --primary-color: #7289da;
  --gray-color: #4f4f4f;
}

body {
  background-color: var(--main-color);
}

/* Form */
form {
  border: 2px solid rgba(255, 255, 255, 0.224);
  border-radius: 5px;
  width: 30%;
  padding: 40px;
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  opacity: 1.2;
  margin-left: 60px;
  margin-top: 50px;
}

form input {
  padding: 6px;
  width: 230px;
  outline: none;
}

input[type="submit"] {
  width: 230px;
  background: var(--primary-color);
  border: none;
  padding: 10px 20px;
  cursor: pointer;
}

.already {
  margin-top: 20px;
}

form p {
  font-family: sans-serif;
  font-size: 14px;
  color: #fff;
}

.input-container p.msg {
  visibility: hidden;
  margin-bottom: 10px;
  margin-top: 5px;
}

.input-container.error p.msg {
  visibility: visible;
}

img {
  width: 51%;
  position: absolute;
  top: 60px;
  right: 10%;
}

.content h1 {
  position: absolute;
  top: 45%;
  right: 38%;
  font-size: 5rem;
  color: #fff;
}

.input-container.error input {
  border-color: red;
}

.input-container.success input {
  border-color: rgb(97, 249, 97);
}