Slender Thin

@font-face {
  font-family: "SlenderThin bold italic";
  src: url("./SlenderThin bold italic.ttf") format("truetype");
  font-weight: 400;
  font-style: normal;
  font-display: swap;
}

@font-face {
  font-family: "SlenderThin bold";
  src: url("./SlenderThin bold.ttf") format("truetype");
  font-weight: 400;
  font-style: normal;
  font-display: swap;
}

@font-face {
  font-family: "SlenderThin italic";
  src: url("./SlenderThin italic.ttf") format("truetype");
  font-weight: 400;
  font-style: normal;
  font-display: swap;
}

@font-face {
  font-family: "SlenderThin";
  src: url("./SlenderThin.ttf") format("truetype");
  font-weight: 400;
  font-style: normal;
  font-display: swap;
}

Self-host the font files from your download. Commercial license → licensing.