style.css

:root {
  --linewidth: 50rem;
  --max-width: 1920px;
  --black: hsl(0, 0%, 20%);
  --white: hsl(0, 0%, 97%);
  --primary: hsl(100, 27%, 50%);
  --container-border: 1rem solid var(--white);
  --grey-dark: hsl(0, 0%, 29%);
  --grey: hsl(0, 0%, 48%);
  --grey-light: hsl(0, 0%, 71%);
}

body,
html {
  margin: 0;
}

body {
  font-family: "Jost", sans-serif;
  font-size: 16px;
  background-color: var(--primary);
  color: var(--black);
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  height: 100vh;
  gap: 2em;
}

h1,
h2 {
  margin: 0;
}

.file-upload a {
  color: var(--primary);
  text-align: center;
}

a {
  color: var(--white);
  text-decoration: underline;
}

.download-button {
  background-color: var(--black);
  border-radius: 2rem;
  padding: 1.5rem;
  text-decoration: none;
  font-weight: 700;
  width: 20rem;
  text-align: center;
  color: var(--white);
  margin: auto;
  display: block;
  margin-top: 40px;
  border: none;
  box-shadow: 0 5px 2px 0 rgba(0, 0, 0, 0.1);
}

input[type="file"] {
  position: absolute;
  top: 0;
  bottom: 0;
  z-index: 50;
  margin: 0;
  padding: 0;
  left: 0;
  right: 0;
  width: 100%;
  height: 100%;
  opacity: 0;
}

.file-upload {
  position: relative;
  background-color: var(--white);
  padding: 30px;
  border-radius: 1em;
  border: 2px solid var(--black);
  flex-direction: column;
  align-items: center;
  justify-content: center;
  display: flex;
  text-align: center;
  font-size: 20px;
  font-weight: 500;
  box-shadow: 0 0 20px 5px rgba(0, 0, 0, 0.2);
}

.read-error {
  text-align: center;
  color: rgb(208, 111, 111);
  font-size: 18px;
  font-weight: 500;
}