/* ============================================================
   Atlas Integrated — Navigation
   Sticky top nav, scroll-triggered background
   ============================================================ */

.site-nav {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: var(--z-nav);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-5);
  padding: var(--space-4) var(--gutter);
  /* Match the body's background exactly (same token) so the nav
     renders identically to the rest of the page. */
  background-color: var(--bg-page);
  backdrop-filter: none;
  -webkit-backdrop-filter: none;
  border-bottom: 1px solid transparent;
  transition: border-color 240ms var(--ease-smooth);
}

.site-nav[data-scrolled="true"] {
  background-color: var(--bg-page);
  border-bottom-color: var(--color-border);
}

.nav-sentinel {
  position: absolute;
  top: 0;
  left: 0;
  width: 1px;
  height: 1px;
  pointer-events: none;
}

.nav-logo {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  color: var(--color-navy);
  transition: opacity 200ms var(--ease-smooth);
}
.nav-logo:hover { opacity: 0.85; }

.nav-logo-mark {
  width: 26px;
  height: 26px;
  display: block;
  flex-shrink: 0;
}

.nav-logo-text {
  font-family: var(--font-display);
  font-size: 1.5rem;
  font-weight: var(--fw-semi);
  letter-spacing: var(--tracking-display-tight);
  line-height: 1;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: var(--space-6);
  font-size: var(--fs-body-sm);
  font-weight: var(--fw-medium);
  letter-spacing: var(--tracking-caption);
}

.nav-links a {
  color: var(--fg-body);
  position: relative;
  padding-block: var(--space-2);
  transition: color 200ms var(--ease-smooth);
}
.nav-links a::after {
  content: "";
  position: absolute;
  left: 0;
  bottom: 0;
  height: 1px;
  width: 0;
  background: var(--color-navy);
  transition: width 240ms var(--ease-smooth);
}
.nav-links a:hover::after,
.nav-links a:focus-visible::after {
  width: 100%;
}

.nav-actions {
  display: flex;
  align-items: center;
  gap: var(--space-3);
}

/* ---- Primary CTA button (used in nav and hero) ---- */

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-2);
  padding: var(--space-3) var(--space-5);
  font-family: var(--font-body);
  font-size: var(--fs-body-sm);
  font-weight: var(--fw-medium);
  letter-spacing: var(--tracking-caption);
  border-radius: var(--radius-md);
  transition:
    background-color 200ms var(--ease-smooth),
    color 200ms var(--ease-smooth),
    box-shadow 220ms var(--ease-smooth),
    transform 180ms var(--ease-card);
  white-space: nowrap;
}

.btn-primary {
  background: var(--btn-primary-bg);
  color: var(--btn-primary-fg);
  min-height: 44px;
}
.btn-primary:hover {
  background: var(--btn-primary-bg-hover);
  box-shadow: 0 0 0 4px oklch(70% 0.10 80 / 0.18);
}
.btn-primary:active {
  transform: translateY(1px);
}

.btn-lg {
  padding: var(--space-4) var(--space-6);
  font-size: var(--fs-body);
  min-height: 52px;
}

/* ---- Mobile hamburger (placeholder for M2 overlay) ---- */

.nav-toggle {
  display: none;
  width: 40px;
  height: 40px;
  align-items: center;
  justify-content: center;
  border-radius: var(--radius-md);
  border: 1px solid transparent;
}
.nav-toggle:hover { border-color: var(--color-border-strong); }
.nav-toggle svg {
  width: 22px;
  height: 22px;
  stroke: currentColor;
  fill: none;
  stroke-width: 1.6;
  stroke-linecap: round;
}

@media (max-width: 767px) {
  .nav-links { display: none; }
  .nav-toggle { display: inline-flex; }
  .nav-actions .btn { display: none; }
}

@media (max-width: 379px) {
  .site-nav { padding-inline: var(--space-4); }
}

/* ============================================================
   Mobile full-screen navigation overlay
   ============================================================ */

.nav-overlay {
  position: fixed;
  inset: 0;
  z-index: var(--z-overlay);
  background: var(--color-navy);
  color: var(--color-surface);
  display: flex;
  flex-direction: column;
  padding: var(--space-5) var(--gutter) var(--space-7);
  /* Hidden by default */
  opacity: 0;
  visibility: hidden;
  pointer-events: none;
  transition:
    opacity 280ms var(--ease-smooth),
    visibility 280ms var(--ease-smooth);
}

.nav-overlay[data-open="true"] {
  opacity: 1;
  visibility: visible;
  pointer-events: auto;
}

@media (min-width: 768px) {
  .nav-overlay { display: none; }
}

.nav-overlay-top {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding-bottom: var(--space-6);
}

.nav-overlay-logo {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  color: var(--color-surface);
}
.nav-overlay-logo svg {
  width: 24px;
  height: 24px;
  display: block;
  flex-shrink: 0;
}
.nav-overlay-logo span {
  font-family: var(--font-display);
  font-size: 1.375rem;
  font-weight: var(--fw-semi);
  letter-spacing: var(--tracking-display-tight);
  line-height: 1;
}

.nav-overlay-close {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 44px;
  height: 44px;
  border-radius: var(--radius-md);
  border: 1px solid transparent;
  color: var(--color-surface);
  background: none;
  transition: border-color 200ms var(--ease-smooth);
}
.nav-overlay-close:hover,
.nav-overlay-close:focus-visible {
  border-color: rgba(247, 244, 236, 0.32);
}
.nav-overlay-close svg {
  width: 22px;
  height: 22px;
  stroke: currentColor;
  fill: none;
  stroke-width: 1.6;
  stroke-linecap: round;
}

.nav-overlay-nav {
  flex: 1;
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  justify-content: center;
  gap: var(--space-5);
}

.nav-overlay-nav a {
  font-family: var(--font-display);
  font-size: clamp(2.5rem, 11vw, 4rem);
  font-weight: var(--fw-semi);
  line-height: 1;
  letter-spacing: var(--tracking-display-tight);
  color: var(--color-surface);
  transition: opacity 200ms var(--ease-smooth);
  /* Stagger entry when overlay opens */
  opacity: 0;
  transform: translateY(12px);
  transition:
    opacity 320ms var(--ease-cinematic),
    transform 320ms var(--ease-cinematic);
}

.nav-overlay[data-open="true"] .nav-overlay-nav a {
  opacity: 1;
  transform: translateY(0);
}
.nav-overlay[data-open="true"] .nav-overlay-nav a:nth-child(1) { transition-delay: 80ms; }
.nav-overlay[data-open="true"] .nav-overlay-nav a:nth-child(2) { transition-delay: 140ms; }
.nav-overlay[data-open="true"] .nav-overlay-nav a:nth-child(3) { transition-delay: 200ms; }

.nav-overlay-nav a:hover,
.nav-overlay-nav a:focus-visible {
  opacity: 0.7;
}

.nav-overlay-footer {
  padding-top: var(--space-6);
  border-top: 1px solid rgba(247, 244, 236, 0.18);
}

.nav-overlay-cta {
  width: 100%;
  background: var(--color-surface);
  color: var(--color-navy);
}
.nav-overlay-cta:hover {
  background: #ffffff;
}

/* Body scroll lock when overlay is open */
body.nav-overlay-open {
  overflow: hidden;
}