/* layout.css — Shared layout utilities and section scaffolding */

/* ─── Site nav ───────────────────────────────────── */

#site-nav {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 100;
  padding: var(--s-5) var(--s-8);
  display: flex;
  justify-content: flex-end;
  align-items: center;
  transition: background-color 300ms ease, backdrop-filter 300ms ease;
}

#site-nav.is-scrolled {
  background-color: rgba(13, 13, 15, 0.8);
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);
}

#site-nav nav {
  display: flex;
  gap: var(--s-8);
}

#site-nav a {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--color-text-muted);
  text-decoration: none;
  transition: color var(--ease-ui);
}

#site-nav a:hover {
  color: var(--color-text-primary);
}

#site-nav a:focus-visible {
  outline: 2px solid var(--color-accent);
  outline-offset: 4px;
  border-radius: var(--radius-sm);
}

@media (max-width: 640px) {
  #site-nav {
    padding-inline: var(--section-pad-x);
  }

  #site-nav nav {
    gap: var(--s-6);
  }
}

/* ─── Container ──────────────────────────────────── */

.container {
  width: 100%;
  max-width: var(--max-width);
  margin-inline: auto;
  padding-inline: var(--section-pad-x);
}

/* ─── Section ────────────────────────────────────── */

.section {
  min-height: 100vh;
  padding-block: var(--section-pad-y);
  display: flex;
  flex-direction: column;
  justify-content: center;
  position: relative;
}

/* Subtle top border between sections */
.section + .section {
  border-top: 1px solid var(--color-border-subtle);
}

/* Offset anchor scroll targets so the fixed nav doesn't cover headings */
.section {
  scroll-margin-top: 56px;
}

/* ─── Section Label ──────────────────────────────── */

.section-label {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  font-weight: var(--font-regular);
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--color-text-muted);
  margin-bottom: var(--s-8);
}

/* ─── Section Title ──────────────────────────────── */

.section-title {
  font-size: var(--text-2xl);
  font-weight: var(--font-medium);
  letter-spacing: -0.025em;
  margin-bottom: var(--s-6);
}

/* ─── Divider ────────────────────────────────────── */

.divider {
  width: 100%;
  height: 1px;
  background-color: var(--color-border);
  border: none;
}

/* ─── Visually hidden (accessibility) ───────────── */

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