/* ===================================================================
   base.css — Foundational typography and layout
   =================================================================== */

/* ---------- Self-hosted fonts ----------
   Note: Place .woff2 files in /assets/fonts/.
   Recommended files (subset to Latin if possible):
   - SourceSerif4-Regular.woff2
   - SourceSerif4-Italic.woff2
   - SourceSerif4-SemiBold.woff2
   - Inter-Regular.woff2
   - Inter-Medium.woff2
   - Inter-SemiBold.woff2
   ---------- */

@font-face {
  font-family: "Source Serif 4";
  font-weight: 400;
  font-style: normal;
  font-display: swap;
  src: url("/assets/fonts/SourceSerif4-Regular.woff2") format("woff2");
}

@font-face {
  font-family: "Source Serif 4";
  font-weight: 400;
  font-style: italic;
  font-display: swap;
  src: url("/assets/fonts/SourceSerif4-Italic.woff2") format("woff2");
}

@font-face {
  font-family: "Source Serif 4";
  font-weight: 600;
  font-style: normal;
  font-display: swap;
  src: url("/assets/fonts/SourceSerif4-SemiBold.woff2") format("woff2");
}

@font-face {
  font-family: "Inter";
  font-weight: 400;
  font-style: normal;
  font-display: swap;
  src: url("/assets/fonts/Inter-Regular.woff2") format("woff2");
}

@font-face {
  font-family: "Inter";
  font-weight: 500;
  font-style: normal;
  font-display: swap;
  src: url("/assets/fonts/Inter-Medium.woff2") format("woff2");
}

@font-face {
  font-family: "Inter";
  font-weight: 600;
  font-style: normal;
  font-display: swap;
  src: url("/assets/fonts/Inter-SemiBold.woff2") format("woff2");
}

/* ---------- Document defaults ---------- */

html {
  font-size: 100%;
  scroll-behavior: smooth;
  background-color: var(--color-cream);
}

body {
  font-family: var(--font-sans);
  font-size: var(--text-base);
  line-height: var(--leading-relaxed);
  color: var(--color-charcoal);
  background-color: var(--color-cream);
}

/* ---------- Skip link ---------- */

.skip-link {
  position: absolute;
  left: 0;
  top: 0;
  padding: var(--space-2) var(--space-3);
  background-color: var(--color-navy);
  color: var(--color-cream);
  font-family: var(--font-sans);
  font-size: var(--text-sm);
  text-decoration: none;
  z-index: 1000;
  transform: translateY(-100%);
  transition: transform var(--transition-fast);
}

.skip-link:focus {
  transform: translateY(0);
  outline: 2px solid var(--color-cream);
  outline-offset: 2px;
}

/* ---------- Typography ---------- */

h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-serif);
  font-weight: 600;
  color: var(--color-navy);
  line-height: var(--leading-snug);
  letter-spacing: var(--tracking-snug);
}

h1 {
  font-size: var(--text-2xl);
  line-height: var(--leading-snug);
}

h2 {
  font-size: var(--text-xl);
  line-height: var(--leading-snug);
}

h3 {
  /* H3 swaps to sans-serif per brief */
  font-family: var(--font-sans);
  font-size: var(--text-lg);
  line-height: var(--leading-normal);
  letter-spacing: var(--tracking-normal);
  color: var(--color-charcoal);
  font-weight: 600;
}

p {
  font-family: var(--font-sans);
  font-size: var(--text-base);
  line-height: var(--leading-relaxed);
  color: var(--color-charcoal);
}

a {
  color: var(--color-navy);
  text-decoration: underline;
  text-decoration-thickness: 1px;
  text-underline-offset: 0.18em;
  transition: color var(--transition-fast), text-decoration-color var(--transition-fast);
}

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

a:focus-visible {
  outline: 2px solid var(--color-navy);
  outline-offset: 2px;
}

strong {
  font-weight: 600;
  color: var(--color-charcoal);
}

em {
  font-style: italic;
}

/* ---------- Container utilities ---------- */

.container {
  width: 100%;
  max-width: var(--container-max);
  margin: 0 auto;
  padding-left: var(--gutter-mobile);
  padding-right: var(--gutter-mobile);
}

.container-narrow {
  max-width: var(--container-narrow);
}

.container-wide {
  max-width: var(--container-wide);
}

@media (min-width: 40rem) {
  .container {
    padding-left: var(--gutter);
    padding-right: var(--gutter);
  }
}

@media (min-width: 64rem) {
  .container {
    padding-left: 3rem;
    padding-right: 3rem;
  }
}

/* ---------- Prose container (long-form) ---------- */

.prose {
  max-width: 65ch;
}

.prose p + p {
  margin-top: var(--space-3);
}

.prose h2 {
  margin-top: var(--space-5);
  margin-bottom: var(--space-3);
}

.prose h3 {
  margin-top: var(--space-4);
  margin-bottom: var(--space-2);
}

/* ---------- Responsive typography ---------- */

@media (min-width: 64rem) {
  h1 {
    font-size: var(--text-2xl);
  }

  h2 {
    font-size: var(--text-xl);
  }

  p {
    font-size: var(--text-base);
  }
}

/* ---------- Section utility ---------- */

.section {
  padding-top: var(--space-5);
  padding-bottom: var(--space-5);
}

@media (min-width: 64rem) {
  .section {
    padding-top: var(--space-7);
    padding-bottom: var(--space-7);
  }
}

.section-divider {
  border: 0;
  border-top: 1px solid var(--color-navy-20);
  margin: 0;
}

/* ---------- Visually hidden ---------- */

.visually-hidden {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}