* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    outline: none;
    font-family: "Inconsolata", monospace;
  }
  
  html {
    font-size: 62.5%;
  }
  
  .container {
    width: 100%;
    height: 100vh;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
  }
  
  .heading {
    position: absolute;
    top: 5rem;
    font-size: 7rem;
    font-weight: 300;
    color: #f03535;
    letter-spacing: 1rem;
    text-shadow: 0.2rem 0.2rem 0.5rem #aaa;
  }
  
  .heading span {
    position: relative;
  }
  
  .heading-span-1 {
    z-index: 10;
  }
  
  .heading-span-2::after {
    content: "";
    position: absolute;
    width: 100%;
    height: 100%;
    background-color: #fff;
    right: -100%;
    transition: right 0.6s;
  }
  
  .change .heading-span-2::after {
    right: 100%;
  }
  
  .buttons {
    position: absolute;
    top: 5rem;
    left: 5rem;
    display: flex;
    flex-direction: column;
  }
  
  .buttons button {
    width: 10rem;
    height: 4rem;
    font-size: 2rem;
    color: #f03535;
    border: none;
    border-radius: 5rem;
    letter-spacing: 0.1rem;
    box-shadow: 0.3rem 0.3rem 0.8rem #eee;
    margin: 1rem 0;
    cursor: pointer;
    transition: background-color 0.3s;
  }
  
  .signin-btn {
    background-color: #e7e7e7;
  }
  
  .change .signin-btn {
    background-color: #fff;
  }
  
  .signup-btn {
    background-color: #fff;
  }
  
  .change .signup-btn {
    background-color: #e7e7e7;
  }
  
  .form-bg {
    position: absolute;
    width: 65rem;
    height: 65rem;
    box-shadow: 1.5rem 1.5rem 1.5rem #ddd;
    transform: rotate(45deg);
  }
  
  .form {
    display: flex;
    flex-direction: column;
    z-index: 100;
  }
  
  .form-input-wrapper {
    margin: 1.5rem 0;
    box-shadow: 0.5rem 0.5rem 0.5rem #eee;
    border-radius: 5rem;
    position: relative;
  }
  
  .form-input-wrapper:nth-child(1),
  .form-input-wrapper:nth-child(4) {
    visibility: hidden;
    opacity: 0;
    transition: all 0.3s;
  }
  
  .change .form-input-wrapper:nth-child(1),
  .change .form-input-wrapper:nth-child(4) {
    visibility: visible;
    opacity: 1;
    transition: all 0.3s 0.3s;
  }
  
  .form input {
    width: 50rem;
    height: 5rem;
    background-color: #fff;
    font-size: 1.7rem;
    padding: 0 2rem;
    letter-spacing: 0.2rem;
    border: none;
    border-radius: 5rem;
  }
  
  .form-input {
    box-shadow: 0.3rem 0.3rem 0.5rem #eee inset;
    color: #888;
  }
  
  .form-input:focus {
    box-shadow: 0.5rem 0.5rem 1rem #eee inset;
  }
  
  .message {
    position: absolute;
    left: 2rem;
    font-size: 1.2rem;
    font-weight: 700;
    letter-spacing: 0.1rem;
    text-transform: uppercase;
    margin-top: 1rem;
    color: #f55e5e;
    visibility: hidden;
    opacity: 0;
    transition: opacity 0.3s;
  }
  
  .error .message {
    visibility: visible;
    opacity: 1;
  }
  
  .success .form-input {
    border: 0.1rem solid #46e75b;
  }
  
  .form-btn {
    box-shadow: 0.5rem 0.5rem 1rem #ddd;
    color: #f03535;
    margin: 2rem 0;
    letter-spacing: 0.2rem;
    font-weight: bold;
    cursor: pointer;
    position: relative;
    top: -6rem;
    transition: top 0.3s 0.3s, box-shadow 0.3s;
  }
  
  .change .form-btn {
    top: 1rem;
    transition: top 0.3s, box-shadow 0.3s;
  }
  
  .form-btn:hover {
    box-shadow: 0.5rem 0.5rem 2rem #ddd;
  }
  
  @media (max-width: 1400px) {
    .form-bg {
      transform: rotate(0);
      height: 55rem;
    }
  }
  
  @media (max-width: 1000px) {
    .heading {
      font-size: 5rem;
    }
  
    .form-bg {
      width: 55rem;
      height: 50rem;
      margin-bottom: 10rem;
    }
  
    .form input {
      width: 40rem;
    }
  }
  
  @media (max-width: 700px) {
    html {
      font-size: 55%;
    }
  
    .heading {
      font-size: 4rem;
      top: 2rem;
    }
  
    .buttons {
      left: 2rem;
      top: 2rem;
    }
  
    .buttons button {
      width: 7rem;
      height: 3rem;
      font-size: 1.7rem;
    }
  
    .form-bg {
      height: 45rem;
      width: 45rem;
    }
  
    .form input {
      width: 35rem;
    }
  }
  
  @media (max-width: 450px) {
    html {
      font-size: 42%;
    }
  }