/* The vault door (markup: build/page-transition.js): two charcoal halves
   meeting on a brass seam, with the logo, a loading bar, and the page's
   title on it. It plays three ways, all on CSS timing:
   - .page-transition--preload: on every load of the home page (no title);
   - html.is-arriving: on a page reached through a link on this site;
   - html.is-leaving: shutting over the page being left (page-transition.js).
   With reduced motion (global.css) it is gone at once and never shuts. */

/* ---------------------------------------------------------------- The door */

/* A full-screen layer above everything (navbar 200, drawer 400), hidden
   unless one of the states below plays it */
.page-transition {
  --door-ease: cubic-bezier(0.76, 0, 0.24, 1);
  position: fixed;
  inset: 0;
  z-index: 999;
  display: grid;
  place-items: center;
  visibility: hidden;
}

/* Each half carries one side of a 1px brass seam, so the two read as a
   single door while they meet */
.page-transition-panel {
  position: absolute;
  top: 0;
  bottom: 0;
  width: 50%;
  background-color: var(--color-panel);
}

.page-transition-panel-left {
  left: 0;
  border-right: 1px solid var(--color-accent-line);
}

.page-transition-panel-right {
  right: 0;
  border-left: 1px solid var(--color-accent-line);
}

/* Keyhole mark, wordmark, and a hairline that fills while the door holds.
   The title hangs below them, out of the flow, so the logo sits in exactly
   the same spot with or without one. */
.page-transition-brand {
  position: relative;
  z-index: 1;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 18px;
  padding: 0 var(--gutter);
}

.page-transition-mark {
  display: grid;
  place-items: center;
  width: 64px;
  height: 64px;
  border: 1px solid var(--color-accent-line);
  border-radius: 50%;
  background: rgba(217, 164, 85, 0.08);
  box-shadow: 0 0 0 7px rgba(217, 164, 85, 0.05);
  color: var(--color-accent-bright);
}

.page-transition-mark .icon {
  width: 28px;
  height: 28px;
}

.page-transition-logo {
  font-family: var(--font-logo);
  font-size: clamp(2.4rem, 8vw, 4.4rem);
  font-weight: 700;
  line-height: 0.9;
  letter-spacing: 0.02em;
  text-transform: uppercase;
  white-space: nowrap;
  color: var(--color-panel-ink);
}

.page-transition-logo span {
  color: var(--color-accent-bright);
}

.page-transition-bar {
  position: relative;
  width: 120px;
  height: 2px;
  overflow: hidden;
  border-radius: 2px;
  background: rgba(241, 236, 225, 0.12);
}

.page-transition-bar::after {
  content: "";
  position: absolute;
  inset: 0;
  background: var(--color-accent-bright);
  transform-origin: left center;
}

/* The page title, under the bar in the site's stamped-label style. CSS
   draws it from data-title (see the markup). It sits on a plate of the
   door's own charcoal, so the seam stops at the title instead of striking
   through its letters. Hidden unless arriving. */
.page-transition-title {
  position: absolute;
  top: calc(100% + 14px);
  left: 50%;
  width: max-content;
  max-width: calc(100vw - 2 * var(--gutter));
  padding: 6px 14px;
  background: var(--color-panel);
  transform: translateX(-50%);
  font-family: var(--font-logo);
  font-size: clamp(1.15rem, 0.95rem + 0.8vw, 1.5rem);
  font-weight: 500;
  line-height: 1.15;
  letter-spacing: 0.12em;
  text-align: center;
  text-transform: uppercase;
  text-wrap: balance;
  color: rgba(241, 236, 225, 0.75);
  opacity: 0;
}

.page-transition-title::before {
  content: attr(data-title);
}

/* ---------------------------------------------------------------- Opening */

/* The door starts shut and holds the logo for 0.8s while the bar fills; the
   logo fades just before the halves swing apart over 0.7s, and the layer
   hides itself at 1.5s. Same timing for the preloader and an arrival. */
.page-transition--preload,
.is-arriving .page-transition {
  visibility: visible;
  animation: page-transition-done 0s linear 1.5s both;
}

.page-transition--preload .page-transition-panel-left,
.is-arriving .page-transition-panel-left {
  animation: page-transition-open-left 0.7s var(--door-ease) 0.8s both;
}

.page-transition--preload .page-transition-panel-right,
.is-arriving .page-transition-panel-right {
  animation: page-transition-open-right 0.7s var(--door-ease) 0.8s both;
}

.page-transition--preload .page-transition-brand,
.is-arriving .page-transition-brand {
  animation: page-transition-brand-out 0.3s ease-in 0.6s both;
}

.page-transition--preload .page-transition-bar::after,
.is-arriving .page-transition-bar::after {
  animation: page-transition-fill 0.55s var(--ease-out) 0.05s both;
}

/* Arriving through a link: the title rises in under the logo at once, and
   fades out with it */
.is-arriving .page-transition-title {
  opacity: 1;
  animation: page-transition-title-in 0.3s var(--ease-out) both;
}

/* ---------------------------------------------------------------- Shutting */

/* Leaving for another page: the halves slide in from the edges and meet in
   0.45s, and the logo settles onto the seam as they close. The bar stays
   empty and no title shows: the next page fills the bar and shows its own
   title, so the hand-off between the two pages is seamless. (Placed after
   Opening so it wins on the home page, whose door is --preload too.) */
.is-leaving .page-transition {
  visibility: visible;
  animation: none;
}

.is-leaving .page-transition-panel-left {
  animation: page-transition-close-left 0.45s var(--door-ease) both;
}

.is-leaving .page-transition-panel-right {
  animation: page-transition-close-right 0.45s var(--door-ease) both;
}

.is-leaving .page-transition-brand {
  animation: page-transition-brand-in 0.2s var(--ease-out) 0.3s both;
}

.is-leaving .page-transition-bar::after {
  transform: scaleX(0);
  animation: none;
}

/* -------------------------------------------------------------- Keyframes */

@keyframes page-transition-open-left {
  to { transform: translateX(-100%); }
}

@keyframes page-transition-open-right {
  to { transform: translateX(100%); }
}

@keyframes page-transition-close-left {
  from { transform: translateX(-100%); }
}

@keyframes page-transition-close-right {
  from { transform: translateX(100%); }
}

@keyframes page-transition-brand-in {
  from { opacity: 0; transform: scale(0.96); }
}

@keyframes page-transition-brand-out {
  to { opacity: 0; transform: scale(0.96); }
}

@keyframes page-transition-fill {
  from { transform: scaleX(0); }
}

@keyframes page-transition-title-in {
  from { opacity: 0; translate: 0 6px; }
}

@keyframes page-transition-done {
  to { visibility: hidden; }
}

/* ------------------------------------------------------------ Scroll lock */

/* The page can't scroll behind the shut door (page-transition.js adds this
   while the door opens). The scrollbar's gutter stays reserved, so nothing
   shifts sideways when the lock lifts. */
html.transition-locked {
  overflow: hidden;
  scrollbar-gutter: stable;
}

/* ------------------------------------------------------------------ Print */

@media print {
  .page-transition {
    display: none;
  }
}