@font-face {
  font-family: "IBM Plex Sans";
  src: url("fonts/IBMPlexSans-Regular.woff2") format("woff2");
  font-weight: 400;
  font-style: normal;
  font-display: swap;
}
@font-face {
  font-family: "IBM Plex Sans";
  src: url("fonts/IBMPlexSans-Bold.woff2") format("woff2");
  font-weight: 700;
  font-style: normal;
  font-display: swap;
}
@font-face {
  font-family: "IBM Plex Serif";
  src: url("fonts/IBMPlexSerif-Regular.woff2") format("woff2");
  font-weight: 400;
  font-style: normal;
  font-display: swap;
}
@font-face {
  font-family: "IBM Plex Serif";
  src: url("fonts/IBMPlexSerif-Italic.woff2") format("woff2");
  font-weight: 400;
  font-style: italic;
  font-display: swap;
}
@font-face {
  font-family: "IBM Plex Serif";
  src: url("fonts/IBMPlexSerif-SemiBold.woff2") format("woff2");
  font-weight: 600;
  font-style: normal;
  font-display: swap;
}
@font-face {
  font-family: "IBM Plex Serif";
  src: url("fonts/IBMPlexSerif-Bold.woff2") format("woff2");
  font-weight: 700;
  font-style: normal;
  font-display: swap;
}

:root {
  --cream: #efefdf;
  --ink: #1a1a1a;
  --gray: #605e5e;
  --green: #3c7a44;
  --green-dark: #1b2e1f;
  --green-light: #9bcba4;
  --line: rgba(26, 26, 26, 0.12);
  --font-sans: "IBM Plex Sans", -apple-system, BlinkMacSystemFont, "Segoe UI", Helvetica, Arial, sans-serif;
  --font-serif: "IBM Plex Serif", Georgia, "Times New Roman", serif;
}

* {
  box-sizing: border-box;
}
html,
body {
  margin: 0;
}
body {
  min-height: 100vh;
  background: var(--cream);
  color: var(--ink);
  font-family: var(--font-sans);
  display: flex;
  flex-direction: column;
}

nav {
  position: sticky;
  top: 0;
  z-index: 10;
  background: var(--cream);
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 32px 40px;
}
nav .brand {
  font-family: var(--font-sans);
  font-weight: 700;
  font-size: 15px;
  letter-spacing: 0.06em;
  color: var(--ink);
  text-decoration: none;
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.18s ease-in-out;
}
nav .brand.is-visible {
  opacity: 1;
  pointer-events: auto;
}
nav ul {
  list-style: none;
  display: flex;
  gap: 40px;
  margin: 0;
  padding: 0;
}
nav a {
  font-family: var(--font-sans);
  color: var(--gray);
  text-decoration: none;
  font-size: 13px;
  font-weight: 700;
  letter-spacing: 0.04em;
  cursor: pointer;
}
nav a:hover,
nav a.active {
  color: var(--ink);
  text-decoration: underline;
  text-underline-offset: 3px;
}

footer {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 24px 40px;
}
footer,
footer a {
  font-family: var(--font-sans);
  font-size: 12px;
  color: var(--gray);
}
footer a {
  text-decoration: none;
}
footer a:hover {
  color: var(--ink);
  text-decoration: underline;
  text-underline-offset: 3px;
}