style.css

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

body {
    font-family: 'Jost', 'Roboto', sans-serif;
    font-weight: 400;
    background-image: url('/assets/nightscout-pro-background.jpeg');
    background-size: cover;
    background-repeat: no-repeat;
    color: white;
}

h1, h2, h3, h4, h5, h6 {
    font-weight: 600;
    text-align: center;
}

h3 {
    margin-bottom: 0.5em;
}

h4 {
    font-weight: 400;
    font-size: 14px;
    margin-top: -0.7em;
    margin-bottom: 0.7em;
}

.container {
    display: flex;
    height: 100vh;
}

.form-container {
    margin: auto;
    padding: 1em;
}

.sub-group {
    border: 2px solid rgba(255, 255, 255, 0.4);
    border-radius: 10px;
    padding: 1em;
    margin-top: 1em;
    background-color: rgba(255, 255, 255, 0.2);
}

input {
    width: 100%;
    padding: 0.5em;
    border-radius: 4px;
    border: none;
    margin-top: 0.2em;
    margin-bottom: 0.8em;
}

button {
    width: 100%;
    padding: 0.5em;
    margin-top: 1em;
    font-size: 18px;
    color: white;
    background: rgb(23,138,109);
    background: linear-gradient(161deg, rgba(23,138,109,1) 0%, rgba(27,160,133,1) 100%);
    border: none;
    border-radius: 4px;
    transition: 300ms ease-in-out;
}

button:hover {
    cursor: pointer;
    background: rgb(19,115,91);
    background: linear-gradient(161deg, rgba(19,115,91,1) 0%, rgba(22,131,109,1) 100%);
}

.logo {
    width: 100%;
    display: flex;
    margin-bottom: 1em;
}

img {
    margin: auto;
}

#loading {
    display: flex;
    position: fixed;
    z-index: 100;
    width: 100%;
    height: 100%;
    background-color: rgba(192, 192, 192, 0.5);
    background-image: url("https://i.stack.imgur.com/MnyxU.gif");
    background-repeat: no-repeat;
    background-position: center;
  }

  .form-flex {
    display: flex;
    justify-content: space-between;
  }

  .form-flex .form-group {
    width: 45%;
  }