/* ==========================================================================
   Shared Layout & Navigation Architecture (Mobile First)
   Prepared for future expansion to additional sections and breakpoints
   ========================================================================== */

.app-shell {
  width: 100%;
  min-height: 100vh;
  min-height: 100dvh;
  position: relative;
}

/* Header & Navigation */
.site-header {
  width: 100%;
  position: relative;
  z-index: var(--z-nav);
}

.site-nav {
  width: 100%;
}

.site-nav__list {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  align-items: center;
  column-gap: clamp(0.65rem, 3.2vw, 1.25rem);
  row-gap: clamp(0.15rem, 0.8vw, 0.4rem);
  width: 100%;
  max-width: 100%;
}

.site-nav__item {
  flex: 0 0 auto;
}

.site-nav__link {
  display: inline-block;
  font-family: var(--font-menu);
  font-weight: 700;
  font-size: clamp(0.84rem, 3.65vw, 0.98rem);
  line-height: 1.25;
  letter-spacing: 0.01em;
  color: var(--color-primary);
  white-space: nowrap;
  padding: 0.25rem 0.22rem;
  transition: var(--transition-link);
  -webkit-tap-highlight-color: transparent;
}

.site-nav__link:hover,
.site-nav__link:focus-visible {
  opacity: 0.78;
}

.site-nav__link:active {
  transform: scale(0.97);
}

/* Shared In-Section Back-to-Top Navigation */
.back-to-top {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.38rem;
  margin-top: clamp(1.25rem, 4.2vw, 1.85rem);
  padding: 0.38rem 0.95rem;
  min-height: 2.35rem;
  border-radius: 999px;
  border: 1px solid var(--color-primary-border);
  background-color: rgba(255, 255, 255, 0.38);
  color: var(--color-primary);
  font-family: var(--font-title);
  font-weight: 400;
  font-size: clamp(0.75rem, 3vw, 0.88rem);
  line-height: 1.2;
  letter-spacing: 0.02em;
  transition: var(--transition-link), background-color 0.2s ease, border-color 0.2s ease;
  -webkit-tap-highlight-color: transparent;
}

.back-to-top__icon {
  width: 0.95em;
  height: 0.95em;
  flex-shrink: 0;
  transition: transform 0.2s ease;
}

@media (hover: hover) {
  .back-to-top:hover {
    background-color: var(--color-primary-tint);
    border-color: var(--color-primary);
  }

  .back-to-top:hover .back-to-top__icon {
    transform: translateY(-2px);
  }
}

.back-to-top:focus-visible {
  background-color: var(--color-primary-tint);
  border-color: var(--color-primary);
}

.back-to-top:active {
  transform: scale(0.97);
}

.back-to-top--on-dark {
  color: var(--color-cream);
  border-color: rgba(251, 235, 213, 0.55);
  background-color: rgba(251, 235, 213, 0.08);
}

@media (hover: hover) {
  .back-to-top--on-dark:hover {
    background-color: rgba(251, 235, 213, 0.18);
    border-color: var(--color-cream);
  }
}

.back-to-top--on-dark:focus-visible {
  background-color: rgba(251, 235, 213, 0.18);
  border-color: var(--color-cream);
  outline-color: var(--color-cream);
}

/* ==========================================================================
   Progressive Breakpoints (Prepared for Tablet & Desktop)
   ========================================================================== */

@media (min-width: 768px) {
  .site-nav__list {
    flex-wrap: nowrap;
    column-gap: clamp(1.25rem, 2.8vw, 2.25rem);
  }

  .site-nav__link {
    font-size: clamp(1rem, 1.6vw, 1.15rem);
    padding: 0.35rem 0.4rem;
  }

  .back-to-top {
    font-size: 0.92rem;
    padding: 0.42rem 1.05rem;
  }
}

@media (min-width: 1024px) {
  .site-nav__list {
    column-gap: clamp(1.75rem, 3vw, 2.75rem);
  }

  .site-nav__link {
    font-size: 1.15rem;
  }
}