:root {
  /* Helvetica-first stack with graceful fallbacks */
  --font-sans: "Helvetica Neue", Helvetica, system-ui, -apple-system,
               BlinkMacSystemFont, Arial, sans-serif;

  /* spacing scale (generous) */
  --space-1: 0.5rem;
  --space-2: 1rem;
  --space-3: 1.5rem;
  --space-4: 2rem;
  --space-5: 3rem;
  --space-6: 4rem;

  /* type scale */
  --font-size-xs: 0.8rem;
  --font-size-sm: 0.9rem;
  --font-size-base: 1rem;
  --font-size-lg: 1.25rem;
  --font-size-xl: 1.75rem;
  --font-size-xxl: 2.5rem;

  /* requested line spacing */
  --line-base: 1.4;
  --line-heading: 1.1;

  --page-max-width: 70rem;
  --border-subtle: 1px solid rgba(0, 0, 0, 0.08);

  --color-bg: #f5f5f5;
  --color-text: #111111;
  --color-accent: #0040ff;
}

/* basic reset */
*,
*::before,
*::after {
  box-sizing: border-box;
}

html,
body {
  margin: 0;
  padding: 0;
}

body {
  font-family: var(--font-sans);
  font-size: var(--font-size-base);
  line-height: var(--line-base);
  color: var(--color-text);
  background-color: var(--color-bg);
  -webkit-font-smoothing: antialiased;
}

/* accessibility: focus styles & skip link */

a {
  color: var(--color-text);
  text-decoration: underline;
  text-decoration-thickness: 1px;
  text-underline-offset: 0.15em;
  text-decoration-skip-ink: auto;
}

a:hover {
  color: var(--color-accent);
}

a:focus-visible {
  outline: 2px solid var(--color-accent);
  outline-offset: 3px;
  text-decoration: none;
}

.skip-link {
  position: absolute;
  left: -999px;
  top: 0;
  padding: var(--space-1) var(--space-2);
  background-color: #ffffff;
  color: #000000;
  z-index: 1000;
}

.skip-link:focus-visible {
  left: 0.5rem;
  top: 0.5rem;
  outline: 2px solid var(--color-accent);
}

/* layout container */

.page {
  min-height: 100vh;
  padding: var(--space-5) var(--space-3) var(--space-3);
  display: flex;
  flex-direction: column;
  align-items: center;
}

.page > * {
  width: 100%;
  max-width: var(--page-max-width);
}

/* header */

.site-header {
  display: flex;
  justify-content: flex-end;
  margin-bottom: var(--space-5);
  border-bottom: var(--border-subtle);
  padding-bottom: var(--space-2);
}

/* navigation */

.site-nav {
  font-size: var(--font-size-sm);
}

.site-nav__list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  gap: var(--space-2);
}

.site-nav__list a {
  text-decoration: none;
  padding-bottom: 0.1em;
  border-bottom: 1px solid transparent;
}

.site-nav__list a:hover {
  border-bottom-color: var(--color-accent);
}

.site-nav__list a:focus-visible {
  outline: 2px solid var(--color-accent);
  outline-offset: 3px;
}

/* main grid */

.layout-grid {
  display: grid;
  grid-template-columns: 2fr 1.2fr;
  column-gap: var(--space-4);
  row-gap: var(--space-5);
  width: 100%;
}

/* sections mapped to grid */

.section--hero {
  grid-column: 1 / -1; /* hero spans full width */
}

.section--info {
  grid-column: 1 / 2;
}

.section--meta {
  grid-column: 2 / 3;
}

/* typography */

h1,
h2 {
  margin: 0 0 var(--space-2);
  font-weight: 700;
}

h1 {
  font-size: var(--font-size-xxl);
  line-height: var(--line-heading);
  /*font-weight: 700; /* heavier name */
}

.section--hero__text {
  margin: 0;
  font-size: var(--font-size-lg);
  max-width: 32rem;
}

.section--info h2,
.section--meta h2 {
  font-size: var(--font-size-sm);
}

/* key lists */

.key-list {
  list-style: none;
  margin: 0;
  padding: 0;
  border-top: var(--border-subtle);
}

.key-list__item {
  display: grid;
  grid-template-columns: minmax(7rem, 10rem) 1fr;
  column-gap: var(--space-2);
  padding-block: var(--space-2); /* more vertical breathing room */
  border-bottom: var(--border-subtle);
}

.key-list__label {
  font-size: var(--font-size-sm);
}

.key-list__text {
  font-size: var(--font-size-sm);
}

.key-list--compact .key-list__item {
  grid-template-columns: minmax(5rem, 8rem) 1fr;
  padding-block: var(--space-2); /* match spacing for compact rows */
}

/* footer */

.site-footer {
  margin-top: auto;
  margin-top: var(--space-5);
  padding-top: var(--space-3);
  border-top: var(--border-subtle);
  font-size: var(--font-size-xs);
}

.site-footer p {
  margin: 0;
}

/* responsive */

@media (max-width: 900px) {
  .page {
    padding-inline: var(--space-2);
    padding-top: var(--space-4);
  }

  .site-header {
    justify-content: flex-start;
  }

  .layout-grid {
    grid-template-columns: 1fr;
  }

  .section--hero,
  .section--info,
  .section--meta {
    grid-column: 1 / -1;
  }

  h1 {
    font-size: 2rem;
  }

  .section--hero__text {
    font-size: var(--font-size-base);
  }
}