:root{
  --content-max-width: 1000px;
  --body-font: system-ui, -apple-system, "Segoe UI", Roboto, "Helvetica Neue", Arial;
  --base-size: 16px;
  --color-text: #111111;
  --color-link: #0645ad; /* accessible blue */
  --color-bg: #ffffff;
  --container-padding: 1rem;
}

/* Responsive base font: ranges between 16px and 18px */
html { font-family: var(--body-font); font-size: clamp(16px, 1.1vw + 0.8rem, 18px); background: var(--color-bg); color: var(--color-text); -webkit-font-smoothing:antialiased; -moz-osx-font-smoothing:grayscale; }

body { margin: 0; line-height: 1.55; }

.container { width: 95%; max-width: var(--content-max-width); margin: 0 auto; padding: var(--container-padding); }

/* Headings */
h1 { font-size: clamp(1.6rem, 2.2vw, 2.25rem); margin: 0 0 0.25rem 0; }
h2 { font-size: clamp(1.1rem, 1.6vw, 1.5rem); margin-top: 1.25rem; }

/* Lead paragraph */
.lead { margin-top: 0.25rem; color: #333; }

/* Grid layout for sections */
.grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 1rem;
  align-items: start;
}

/* Lists and links */
ul { margin: 0.25rem 0 0 1rem; padding: 0; }
a { color: var(--color-link); text-decoration: underline; }
a:focus-visible { outline: 3px solid highlight; outline-offset: 3px; }

/* Footer */
.site-footer { font-size: 0.9rem; color: #555; margin-top: 2rem; }

/* Accessibility: ensure contrast and readable line length */
@media (min-width: 900px) {
  .container { font-size: 1rem; }
}