theme.css

@font-face {
  font-family: "system-ui";
  font-style: normal;
  font-weight: 300;
  src: local(".SFNS-Light"), local(".SFNSText-Light"), local(".HelveticaNeueDeskInterface-Light"), local(".LucidaGrandeUI"), local("Segoe UI Light"), local("Ubuntu Light"), local("Roboto-Light"), local("DroidSans"), local("Tahoma");
}


/* Dark theme: default */
:root {
  color-scheme: dark;
  --color-background: #38444c;
  --color-border: #697278;
  --color-text-default: #f0f2f3;
  --color-base: #293238;
  --color-accent: #ec1a62;
  --font-family-primary: -apple-system, BlinkMacSystemFont, Segoe UI, Roboto, Oxygen, Ubuntu, Cantarell, Fira Sans, Droid Sans, Helvetica Neue, sans-serif;
  --font-family-secondary: "system-ui";
  --font-size: clamp(1rem, 2.5vw, 1.2rem);
  --border-radius: 5px;
}

p {
  word-spacing: .05em;
  line-height: 1.5;
}

button {
  font-size: inherit;
}

img {
  filter: drop-shadow(0 2px 4px #0b0b0b);
  max-width: 100vw;
  opacity: .75;
  transition: opacity .5s ease-in-out;
}

img:hover {
  opacity: 1;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, Segoe UI, Roboto,
    Oxygen, Ubuntu, Cantarell, Fira Sans, Droid Sans, Helvetica Neue,
    sans-serif;
  background-color: var(--color-background);
  color: var(--color-text-default);
  padding: 0;
  margin: 0;
  font-size: var(--font-size);
}

* {
  box-sizing: border-box;
  font-family: var(--font-family);
}


a.button, button {
  padding: 0.5rem 1rem;
  color: var(--color-text-default);
  background-color: var(--color-base);
  border-color: var(--color-border);
  border-radius: var(--border-radius);
}


@media (prefers-color-scheme: light) {
  :root {
    color-scheme: light;
    --color-background: antiquewhite;
    --color-border: #cacfd5;
    --color-text-default: #0b1016;
    --color-base: #f4f5f6;
    --color-accent: #ba0d37;
  }

  img {
    filter: drop-shadow(0 2px 4px #969696);
  }
}