/* ============================================
   Layout — Container, grid, utilities
   ============================================ */

.container {
  width: 100%;
  max-width: var(--max-w);
  margin-inline: auto;
  padding-inline: var(--sp-5);
}

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

.grid {
  display: grid;
  gap: var(--grid-gap);
}

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

@media (max-width: 1024px) {
  .grid-4 { grid-template-columns: repeat(2, 1fr); }
  .grid-3 { grid-template-columns: repeat(2, 1fr); }
}

@media (max-width: 640px) {
  .grid-2, .grid-3, .grid-4 { grid-template-columns: 1fr; }
}

.flex { display: flex; }
.flex-col { flex-direction: column; }
.flex-wrap { flex-wrap: wrap; }
.items-center { align-items: center; }
.items-start { align-items: flex-start; }
.items-end { align-items: flex-end; }
.justify-center { justify-content: center; }
.justify-between { justify-content: space-between; }
.justify-end { justify-content: flex-end; }
.gap-1 { gap: var(--sp-1); }
.gap-2 { gap: var(--sp-2); }
.gap-3 { gap: var(--sp-3); }
.gap-4 { gap: var(--sp-4); }
.gap-6 { gap: var(--sp-6); }
.gap-8 { gap: var(--sp-8); }

.text-center { text-align: center; }
.text-left { text-align: left; }
.text-right { text-align: right; }
.text-uppercase { text-transform: uppercase; }
.text-sm { font-size: var(--fs-sm); }
.text-xs { font-size: var(--fs-xs); }
.text-lg { font-size: var(--fs-lg); }
.text-muted { color: var(--c-text-muted); }
.text-secondary { color: var(--c-text-secondary); }
.text-primary { color: var(--c-primary-500); }
.text-accent { color: var(--c-accent-500); }
.text-white { color: var(--c-text-inverse); }
.fw-medium { font-weight: var(--fw-medium); }
.fw-semibold { font-weight: var(--fw-semibold); }
.fw-bold { font-weight: var(--fw-bold); }
.ls-wide { letter-spacing: var(--ls-wide); }
.ls-wider { letter-spacing: var(--ls-wider); }

.mt-2 { margin-top: var(--sp-2); }
.mt-4 { margin-top: var(--sp-4); }
.mt-6 { margin-top: var(--sp-6); }
.mt-8 { margin-top: var(--sp-8); }
.mb-2 { margin-bottom: var(--sp-2); }
.mb-4 { margin-bottom: var(--sp-4); }
.mb-6 { margin-bottom: var(--sp-6); }
.mb-8 { margin-bottom: var(--sp-8); }

.section {
  padding-block: var(--section-py);
}

.section--alt { background-color: var(--c-bg-alt); }
.section--dark { background: linear-gradient(180deg, var(--c-bg-alt) 0%, var(--c-bg-dark) 100%); }
.section--dark h2, .section--dark h3, .section--dark h4 { color: var(--c-text); }
.section--dark p { color: var(--c-text-secondary); }
.section--primary {
  background: var(--grad-violet);
  position: relative;
}
.section--primary h2, .section--primary h3 { color: #fff; }
.section--primary p { color: rgba(255, 255, 255, 0.75); }

.section-header {
  text-align: center;
  max-width: 680px;
  margin-inline: auto;
  margin-bottom: var(--sp-12);
}

.section-header__tag {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  font-size: var(--fs-xs);
  font-weight: var(--fw-bold);
  text-transform: uppercase;
  letter-spacing: 0.14em;
  color: var(--c-accent-500);
  margin-bottom: var(--sp-3);
  padding: 0.375rem 0.875rem;
  background: rgba(34, 211, 238, 0.08);
  border: 1px solid rgba(34, 211, 238, 0.25);
  border-radius: var(--radius-full);
}

.section--dark .section-header__tag,
.section--primary .section-header__tag {
  background: rgba(34, 211, 238, 0.12);
  border-color: rgba(34, 211, 238, 0.3);
  color: var(--c-accent-500);
}

.section-header h2 {
  font-family: var(--ff-display);
  margin-bottom: var(--sp-4);
}

.section-header p {
  font-size: var(--fs-lg);
  color: var(--c-text-muted);
  line-height: var(--lh-relaxed);
}

.section--dark .section-header p,
.section--primary .section-header p {
  color: var(--c-text-secondary);
}

.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;
}

.skip-link {
  position: fixed;
  top: -100%;
  left: var(--sp-4);
  z-index: 9999;
  padding: var(--sp-3) var(--sp-6);
  background: var(--c-bg-alt);
  color: var(--c-text-inverse);
  font-weight: var(--fw-semibold);
  border: 1px solid var(--c-border-strong);
  border-radius: 0 0 var(--radius-md) var(--radius-md);
  transition: top var(--t-fast);
}

.skip-link:focus {
  top: 0;
  outline: 2px solid var(--c-accent-500);
  outline-offset: 2px;
}

.fade-in {
  opacity: 0;
  transform: translateY(20px);
  transition: opacity 0.6s var(--ease), transform 0.6s var(--ease);
}

.fade-in.visible {
  opacity: 1;
  transform: translateY(0);
}

.fade-in-left {
  opacity: 0;
  transform: translateX(-30px);
  transition: opacity 0.6s var(--ease), transform 0.6s var(--ease);
}

.fade-in-left.visible {
  opacity: 1;
  transform: translateX(0);
}

.fade-in-right {
  opacity: 0;
  transform: translateX(30px);
  transition: opacity 0.6s var(--ease), transform 0.6s var(--ease);
}

.fade-in-right.visible {
  opacity: 1;
  transform: translateX(0);
}