/* ==========================================================================
   layout.css — Structural layout: container, header, hero, sections, footer
   ========================================================================== */

@layer layout {
  /* ---------- Container & section rhythm ---------- */
  .container {
    width: 100%;
    max-width: var(--container);
    margin-inline: auto;
    padding-inline: var(--gutter);
  }
  .container--narrow { max-width: var(--container-narrow); }

  .section {
    padding-block: var(--section-pad);
    position: relative;
  }
  .section + .section { padding-block-start: 0; }
  .section-inner { padding-block-start: var(--section-pad); }

  .section-head {
    max-width: 46rem;
    margin-block-end: var(--space-7);
  }
  .section-head--center {
    margin-inline: auto;
    text-align: center;
  }

  .eyebrow {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    font-size: var(--fs-xs);
    font-weight: 600;
    letter-spacing: var(--tracking-wide);
    text-transform: uppercase;
    color: var(--primary);
    margin-block-end: var(--space-4);
  }
  .eyebrow::before {
    content: "";
    width: 1.75rem;
    height: 1px;
    background: currentColor;
    opacity: 0.5;
  }
  .section-head--center .eyebrow { justify-content: center; }

  .section-title {
    font-size: var(--fs-xl);
    margin-block-end: var(--space-4);
  }
  .section-lead {
    font-size: var(--fs-md);
    color: var(--text-2);
    line-height: var(--lh-snug);
    max-width: 40rem;
  }
  .section-head--center .section-lead { margin-inline: auto; }

  /* ---------- Header ---------- */
  .site-header {
    position: fixed;
    inset-block-start: 0;
    inset-inline: 0;
    z-index: var(--z-header);
    height: var(--header-h);
    display: flex;
    align-items: center;
    transition: transform var(--dur) var(--ease-out);
  }
  .site-header__bar {
    width: 100%;
    max-width: var(--container);
    margin-inline: auto;
    margin-block-start: 0.75rem;
    padding: 0.5rem 0.5rem 0.5rem 1.25rem;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: var(--space-4);
    border-radius: var(--radius-pill);
    background: var(--glass-bg);
    border: 1px solid transparent;
    -webkit-backdrop-filter: blur(16px) saturate(1.4);
    backdrop-filter: blur(16px) saturate(1.4);
    transition: background var(--dur) var(--ease-out),
                border-color var(--dur) var(--ease-out),
                box-shadow var(--dur) var(--ease-out);
  }
  .site-header[data-scrolled="true"] .site-header__bar {
    border-color: var(--glass-border);
    box-shadow: var(--shadow-md);
  }

  .brand {
    display: inline-flex;
    align-items: center;
    gap: 0.625rem;
    font-family: var(--font-display);
    font-weight: 800;
    font-size: var(--fs-md);
    letter-spacing: var(--tracking-tight);
    color: var(--text);
  }
  .brand__mark {
    display: grid;
    place-items: center;
    width: 2rem; height: 2rem;
    border-radius: 9px;
    background: linear-gradient(135deg, var(--primary), var(--secondary));
    color: #fff;
    font-size: 0.95rem;
    box-shadow: var(--shadow-sm);
  }

  .primary-nav { display: none; }
  @media (min-width: 900px) {
    .primary-nav { display: flex; align-items: center; gap: 0.25rem; }
  }
  .primary-nav__link {
    position: relative;
    padding: 0.5rem 0.875rem;
    font-size: var(--fs-sm);
    font-weight: 500;
    color: var(--text-2);
    border-radius: var(--radius-pill);
  }
  .primary-nav__link:hover { color: var(--text); }
  .primary-nav__link[aria-current="true"] {
    color: var(--text);
    background: var(--surface-2);
  }

  .header-actions { display: flex; align-items: center; gap: 0.5rem; }

  /* ---------- Hero ---------- */
  .hero {
    position: relative;
    padding-block: calc(var(--header-h) + clamp(3rem, 2rem + 6vw, 6rem)) var(--section-pad);
    overflow: clip;
    isolation: isolate;
  }
  .hero__grid-bg {
    position: absolute;
    inset: 0;
    z-index: -2;
    background-image:
      linear-gradient(to right, var(--grid-line) 1px, transparent 1px),
      linear-gradient(to bottom, var(--grid-line) 1px, transparent 1px);
    background-size: 56px 56px;
    -webkit-mask-image: radial-gradient(ellipse 80% 60% at 50% 0%, #000 30%, transparent 75%);
    mask-image: radial-gradient(ellipse 80% 60% at 50% 0%, #000 30%, transparent 75%);
  }
  .hero__aurora {
    position: absolute;
    inset: -20% -10% auto -10%;
    height: 70%;
    z-index: -1;
    filter: blur(70px) saturate(1.3);
    opacity: 0.75;
    pointer-events: none;
  }
  .hero__aurora::before,
  .hero__aurora::after {
    content: "";
    position: absolute;
    border-radius: 50%;
  }
  .hero__aurora::before {
    width: 42vw; height: 42vw;
    inset-block-start: -8vw;
    inset-inline-start: 8vw;
    background: radial-gradient(circle, var(--aurora-1), transparent 65%);
    animation: drift-a 22s var(--ease-in-out) infinite alternate;
  }
  .hero__aurora::after {
    width: 38vw; height: 38vw;
    inset-block-start: -4vw;
    inset-inline-end: 6vw;
    background: radial-gradient(circle, var(--aurora-2), transparent 65%);
    animation: drift-b 26s var(--ease-in-out) infinite alternate;
  }
  .hero__aurora-3 {
    position: absolute;
    inset: 0; z-index: -1;
  }
  .hero__aurora-3::before {
    content: "";
    position: absolute;
    inset-block-start: 2vw;
    inset-inline-start: 38%;
    width: 30vw; height: 30vw;
    border-radius: 50%;
    background: radial-gradient(circle, var(--aurora-3), transparent 60%);
    filter: blur(70px);
    opacity: 0.55;
    animation: drift-c 30s var(--ease-in-out) infinite alternate;
  }

  @keyframes drift-a { to { transform: translate3d(6%, 8%, 0) scale(1.15); } }
  @keyframes drift-b { to { transform: translate3d(-7%, 5%, 0) scale(1.1); } }
  @keyframes drift-c { to { transform: translate3d(4%, -6%, 0) scale(1.2); } }

  .hero__inner {
    max-width: 52rem;
    margin-inline: auto;
    text-align: center;
  }
  .hero__title {
    font-size: var(--fs-3xl);
    margin-block: var(--space-5) var(--space-5);
  }
  .hero__title .grad-text {
    background: linear-gradient(115deg, var(--primary), var(--accent));
    -webkit-background-clip: text;
    background-clip: text;
    color: transparent;
  }
  .hero__lead {
    font-size: var(--fs-md);
    color: var(--text-2);
    max-width: 38rem;
    margin-inline: auto;
    margin-block-end: var(--space-6);
  }
  .hero__actions {
    display: flex;
    flex-wrap: wrap;
    gap: var(--space-3);
    justify-content: center;
  }
  .hero__stats {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: var(--space-4);
    max-width: 38rem;
    margin: var(--space-8) auto 0;
    padding-block-start: var(--space-6);
    border-block-start: 1px solid var(--border);
  }
  .hero__stat-value {
    font-family: var(--font-display);
    font-size: var(--fs-lg);
    font-weight: 800;
    color: var(--text);
  }
  .hero__stat-label {
    font-size: var(--fs-xs);
    color: var(--text-2);
    text-transform: uppercase;
    letter-spacing: var(--tracking-wide);
  }

  /* ---------- Footer ---------- */
  .site-footer {
    margin-block-start: var(--section-pad);
    border-block-start: 1px solid var(--border);
    background: var(--surface-2);
  }
  .footer-grid {
    display: grid;
    gap: var(--space-7);
    padding-block: var(--space-8);
    grid-template-columns: 1fr;
  }
  @media (min-width: 720px) {
    .footer-grid { grid-template-columns: 1.5fr 1fr 1fr; }
  }
  .footer-brand__text {
    color: var(--text-2);
    font-size: var(--fs-sm);
    max-width: 28ch;
    margin-block-start: var(--space-3);
  }
  .footer-col__title {
    font-size: var(--fs-xs);
    text-transform: uppercase;
    letter-spacing: var(--tracking-wide);
    color: var(--text-3);
    margin-block-end: var(--space-4);
  }
  .footer-col ul { display: grid; gap: var(--space-3); }
  .footer-col a { color: var(--text-2); font-size: var(--fs-sm); }
  .footer-col a:hover { color: var(--text); }
  .footer-bottom {
    display: flex;
    flex-wrap: wrap;
    gap: var(--space-4);
    justify-content: space-between;
    align-items: center;
    padding-block: var(--space-5);
    border-block-start: 1px solid var(--border);
    color: var(--text-3);
    font-size: var(--fs-sm);
  }
}