.container {
  width: 100%;
  max-width: 1280px;
  margin: 0 auto;
  padding-inline: var(--space-4);
}

/* Rhythmic Pacing */
.section-padding {
  padding-block: var(--space-16);
}

.section-padding-lg {
  padding-block: var(--space-24);
}

.section-padding-sm {
  padding-block: var(--space-8);
}

.pt-lg { padding-top: var(--space-24); }
.pb-sm { padding-bottom: var(--space-8); }
.pt-sm { padding-top: var(--space-8); }
.pb-lg { padding-bottom: var(--space-24); }
.pb-none { padding-bottom: 0; }

/* Grid System */
.grid {
  display: grid;
  gap: var(--space-8);
}

.grid-2 { grid-template-columns: repeat(2, 1fr); }
.grid-3 { grid-template-columns: repeat(3, 1fr); }
.grid-4 { grid-template-columns: repeat(4, 1fr); }

/* Asymmetrical Grids */
.grid-5-split {
  grid-template-columns: 3fr 2fr;
}

/* Alignments */
.items-center { align-items: center; }
.items-start { align-items: start; }
.align-end { align-self: end; } /* For staggering */

.gap-sm { gap: var(--space-4); }
.gap-md { gap: var(--space-8); }
.gap-lg { gap: var(--space-12); }
.gap-xl { gap: var(--space-16); }

/* Layout Backgrounds */
.bg-secondary {
  background-color: var(--color-bg-secondary);
}

.bg-dark {
  background-color: var(--color-text-primary);
  color: var(--color-bg-primary);
}

.bg-dark h1, .bg-dark h2, .bg-dark h3, .bg-dark h4 {
  color: var(--color-bg-primary);
}

/* Header & Footer */
.header {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  z-index: 100;
  padding-block: var(--space-6); /* slightly larger resting padding */
  transition: background-color var(--transition-fast), backdrop-filter var(--transition-fast), box-shadow var(--transition-fast), padding var(--transition-fast);
}

.header.scrolled {
  background-color: rgba(253, 251, 247, 0.95);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  box-shadow: var(--shadow-sm);
  padding-block: var(--space-3); /* compress on scroll */
}

.header__inner {
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.nav__list {
  display: flex;
  gap: var(--space-8); /* increased spacing */
}

.nav__link {
  font-size: 0.8125rem; /* refined typography */
  font-weight: 600;
  color: var(--color-text-primary);
  position: relative;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  transition: opacity var(--transition-fast);
}

.nav__list:hover .nav__link:not(:hover) {
  opacity: 0.5; /* dim siblings on hover for focus */
}

.nav__link::after {
  content: '';
  position: absolute;
  bottom: -4px;
  left: 0;
  width: 100%;
  height: 1px;
  background-color: var(--color-text-primary);
  transform: scaleX(0);
  transform-origin: right;
  transition: transform var(--transition-smooth);
}

.nav__link:hover::after, .nav__link.active::after {
  transform: scaleX(1);
  transform-origin: left;
}

/* Mobile Nav Toggle */
.nav-toggle {
  display: none;
  width: 24px;
  height: 24px;
  position: relative;
  z-index: 101;
  background: transparent;
  border: none;
  cursor: pointer;
}

.nav-toggle span {
  display: block;
  position: absolute;
  height: 2px;
  width: 100%;
  background: var(--color-text-primary);
  transition: all var(--transition-fast);
}

.nav-toggle span:nth-child(1) { top: 4px; }
.nav-toggle span:nth-child(2) { top: 11px; }
.nav-toggle span:nth-child(3) { top: 18px; }

.nav-toggle.active span:nth-child(1) { top: 11px; transform: rotate(45deg); }
.nav-toggle.active span:nth-child(2) { opacity: 0; }
.nav-toggle.active span:nth-child(3) { top: 11px; transform: rotate(-45deg); }

.mobile-menu {
  position: fixed;
  top: 0;
  left: 0;
  width: 100vw;
  height: 100vh;
  background-color: var(--color-bg-primary);
  z-index: 99;
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  opacity: 0;
  pointer-events: none;
  transition: opacity var(--transition-smooth);
}

.mobile-menu.active {
  opacity: 1;
  pointer-events: auto;
}

.mobile-menu__list {
  display: flex;
  flex-direction: column;
  gap: var(--space-8);
  text-align: center;
}

.mobile-menu__link {
  font-family: var(--font-serif);
  font-size: 2.5rem;
  color: var(--color-text-primary);
}

.footer {
  padding-top: var(--space-16); /* increased breathing room */
  padding-bottom: var(--space-8);
  border-top: 1px solid var(--color-border);
}

.footer__grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr;
  gap: var(--space-8);
}