/* =============================================================================
   VERTEX DIMENSION — Layout
   Containers, field, nav, progress, section frame. Structure, not skin.
   ========================================================================== */

/* --- Generative field: fixed behind all content ------------------------ */
.field {
  position: fixed;
  inset: 0;
  z-index: var(--z-field);
  pointer-events: none;
}
#field-canvas {
  width: 100%;
  height: 100%;
  display: block;
  opacity: 0;
  transition: opacity 1.6s var(--ease-out);
}
#field-canvas.is-ready {
  opacity: 1;
}

/* A faint coordinate plane — graph-paper, not decoration. Pure hairlines. */
.field__grid {
  position: absolute;
  inset: -2px;
  background-image: linear-gradient(
      to right,
      var(--grid-line) 1px,
      transparent 1px
    ),
    linear-gradient(to bottom, var(--grid-line) 1px, transparent 1px);
  background-size: clamp(72px, 7vw, 116px) clamp(72px, 7vw, 116px);
  /* Fade the grid away from the optical centre so copy stays uncluttered. */
  -webkit-mask-image: radial-gradient(
    circle at 50% 38%,
    rgba(0, 0, 0, 0.9),
    transparent 78%
  );
  mask-image: radial-gradient(
    circle at 50% 38%,
    rgba(0, 0, 0, 0.9),
    transparent 78%
  );
}

/* Everything readable sits above the field */
.page {
  position: relative;
  z-index: var(--z-content);
}

/* --- Containers -------------------------------------------------------- */
.container {
  width: 100%;
  max-width: var(--container);
  margin-inline: auto;
  padding-inline: var(--gutter);
}
.container--wide {
  max-width: var(--container-wide);
}

/* =============================================================================
   Navigation — a fixed measurement bar
   ========================================================================== */
.nav {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: var(--z-nav);
  height: var(--nav-h);
  display: flex;
  align-items: center;
  background: color-mix(in srgb, var(--vd-black) 62%, transparent);
  backdrop-filter: blur(14px) saturate(0);
  -webkit-backdrop-filter: blur(14px) saturate(0);
  border-bottom: 1px solid transparent;
  transition: border-color var(--dur-mid) var(--ease-out),
    background var(--dur-mid) var(--ease-out);
}
.nav.is-scrolled {
  border-bottom-color: var(--line);
  background: color-mix(in srgb, var(--vd-black) 80%, transparent);
}
.nav__inner {
  width: 100%;
  max-width: var(--container-wide);
  margin-inline: auto;
  padding-inline: var(--gutter);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-5);
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 0.7rem;
}
.brand__mark {
  width: 26px;
  height: 26px;
  flex: none;
}
.brand__word {
  font-size: 0.82rem;
  font-weight: var(--weight-medium);
  letter-spacing: var(--track-wide);
  text-transform: uppercase;
  color: var(--ink-090);
  white-space: nowrap;
}
.brand__word small {
  display: block;
  font-family: var(--font-mono);
  font-size: 0.56rem;
  font-weight: var(--weight-regular);
  letter-spacing: var(--track-wide);
  color: var(--ink-035);
  margin-top: 2px;
}

.nav__menu {
  display: flex;
  align-items: center;
  gap: clamp(1rem, 0.4rem + 1.4vw, 2.2rem);
}
.nav__link {
  position: relative;
  font-family: var(--font-mono);
  font-size: var(--fs-label);
  letter-spacing: var(--track-wide);
  text-transform: uppercase;
  color: var(--ink-050);
  transition: color var(--dur-fast) var(--ease-out);
  padding-block: 0.4rem;
}
.nav__link .idx {
  color: var(--ink-020);
  margin-right: 0.5em;
}
.nav__link:hover,
.nav__link.is-active {
  color: var(--ink-100);
}
.nav__link.is-active .idx {
  color: var(--ink-050);
}

.nav__tools {
  display: flex;
  align-items: center;
  gap: var(--space-4);
}

/* Compact CTA in the nav rail (the global .btn is too tall for 72px) */
.nav__contact {
  padding: 0.55rem 1.05rem;
}

/* Language toggle */
.lang {
  display: inline-flex;
  align-items: center;
  font-family: var(--font-mono);
  font-size: var(--fs-label);
  letter-spacing: var(--track-wide);
  border: 1px solid var(--line-strong);
}
.lang__btn {
  padding: 0.35rem 0.6rem;
  color: var(--ink-050);
  transition: color var(--dur-fast) var(--ease-out),
    background var(--dur-fast) var(--ease-out);
}
.lang__btn[aria-pressed="true"] {
  background: var(--vd-white);
  color: var(--vd-black);
}

/* Scroll progress — a hairline that fills the top edge */
.progress {
  position: fixed;
  top: 0;
  left: 0;
  height: 1px;
  width: 100%;
  transform: scaleX(0);
  transform-origin: left;
  background: var(--vd-white);
  z-index: calc(var(--z-nav) + 1);
  will-change: transform;
}

/* Mobile menu trigger (hidden on desktop) */
.nav__burger {
  display: none;
  width: 30px;
  height: 20px;
  position: relative;
}
.nav__burger span {
  position: absolute;
  left: 0;
  width: 100%;
  height: 1px;
  background: var(--ink-090);
  transition: transform var(--dur-fast) var(--ease-out),
    opacity var(--dur-fast) var(--ease-out);
}
.nav__burger span:nth-child(1) { top: 4px; }
.nav__burger span:nth-child(2) { top: 50%; }
.nav__burger span:nth-child(3) { bottom: 4px; }

/* =============================================================================
   Section frame
   ========================================================================== */
.section {
  position: relative;
  padding-block: var(--section-pad-y);
}
.section + .section {
  border-top: 1px solid var(--line);
}

/* Section header: index + kicker, like a numbered plate in a deck */
.section__head {
  display: flex;
  align-items: baseline;
  gap: var(--space-5);
  margin-bottom: clamp(2.5rem, 1.5rem + 3vw, 5rem);
  flex-wrap: wrap;
}
.section__index {
  font-family: var(--font-mono);
  font-size: var(--fs-label);
  letter-spacing: var(--track-wide);
  color: var(--ink-035);
  white-space: nowrap;
}
.section__kicker {
  font-family: var(--font-mono);
  font-size: var(--fs-label);
  letter-spacing: var(--track-wider);
  text-transform: uppercase;
  color: var(--ink-070);
}

/* A reusable two-column editorial split */
.split {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(2rem, 1rem + 4vw, 5rem);
}
@media (min-width: 900px) {
  .split--12 {
    grid-template-columns: 0.9fr 1.1fr;
  }
  .split--21 {
    grid-template-columns: 1.1fr 0.9fr;
  }
  .split--center {
    align-items: center;
  }
}

/* Hairline divider */
.rule {
  height: 1px;
  background: var(--line);
  border: 0;
  width: 100%;
}

/* =============================================================================
   Footer
   ========================================================================== */
.footer {
  position: relative;
  z-index: var(--z-content);
  border-top: 1px solid var(--line-strong);
  padding-block: var(--space-9) var(--space-6);
}
.footer__grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-7);
}
@media (min-width: 760px) {
  .footer__grid {
    grid-template-columns: 2fr 1fr;
  }
}
.footer__bottom {
  margin-top: var(--space-9);
  padding-top: var(--space-5);
  border-top: 1px solid var(--line);
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: var(--space-4);
  flex-wrap: wrap;
}

/* =============================================================================
   Responsive nav
   ========================================================================== */
@media (max-width: 880px) {
  .nav__menu {
    position: fixed;
    inset: var(--nav-h) 0 auto 0;
    flex-direction: column;
    align-items: flex-start;
    gap: 0;
    background: color-mix(in srgb, var(--vd-black) 96%, transparent);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border-bottom: 1px solid var(--line);
    padding: var(--space-4) var(--gutter) var(--space-6);
    transform: translateY(-12px);
    opacity: 0;
    pointer-events: none;
    transition: transform var(--dur-mid) var(--ease-out),
      opacity var(--dur-mid) var(--ease-out);
  }
  .nav.is-open .nav__menu {
    transform: translateY(0);
    opacity: 1;
    pointer-events: auto;
  }
  .nav__link {
    width: 100%;
    padding-block: var(--space-4);
    font-size: var(--fs-small);
    border-bottom: 1px solid var(--line);
  }
  .nav__contact {
    width: 100%;
    justify-content: center;
    margin-top: var(--space-5);
    padding: var(--space-4);
  }
  .nav__burger {
    display: block;
  }
  .nav.is-open .nav__burger span:nth-child(1) {
    transform: translateY(6px) rotate(45deg);
  }
  .nav.is-open .nav__burger span:nth-child(2) {
    opacity: 0;
  }
  .nav.is-open .nav__burger span:nth-child(3) {
    transform: translateY(-6px) rotate(-45deg);
  }
}