/* ==========================================================================
   Chrome: the top bar and the floating rail
   Site furniture that persists across every page, home and case study alike.
   ========================================================================== */

/* ==========================================================================
   Top bar: wordmark only, navigation lives in the rail
   ========================================================================== */

.bar {
  position: fixed;
  inset: 0 0 auto 0;
  z-index: 60;
  height: var(--bar-h);
  pointer-events: none;
}

.bar__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  height: 100%;
}

.bar::before {
  content: "";
  position: absolute;
  inset: 0;
  /* Solid, not a backdrop-filter: blurring the backdrop forces a GPU readback
     of whatever is underneath every frame, and underneath is the pinned deck's
     full-width composited track. That combination stalls the renderer. */
  background: var(--paper);
  opacity: 0;
  transition: opacity 0.4s var(--ease);
}
.bar.is-stuck::before { opacity: 1; }

.bar__rule {
  position: absolute;
  inset: auto 0 0 0;
  height: 1px;
  background: var(--rule);
  transform: scaleX(0);
  transform-origin: left center;
  transition: transform 0.6s var(--ease);
}
.bar.is-stuck .bar__rule { transform: scaleX(1); }

/* The bar itself stays transparent to the pointer so it never blocks the page
   underneath it, but everything placed in it must still be clickable.
   Opting the children in as a group rather than naming them one by one is
   deliberate: the previous allow-list silently dropped the mode switch and the
   palette trigger as each was added, and a control that cannot be clicked
   looks identical to one that works until someone tries it with a mouse. */
.bar__inner > * { position: relative; z-index: 1; pointer-events: auto; }

.bar__mark {
  display: flex;
  align-items: center;
  min-height: 2.75rem;
  font-family: var(--font-display);
  font-weight: 600;
  font-size: clamp(0.95rem, 0.85rem + 0.4vw, 1.1rem);
  letter-spacing: -0.02em;
  text-decoration: none;
}
.bar__mark-full { display: none; }
@media (min-width: 34rem) {
  .bar__mark-short { display: none; }
  .bar__mark-full { display: block; }
}

.bar__meta { color: var(--ink-faint); }
@media (max-width: 44rem) { .bar__meta { display: none; } }

/* The switch sits at the end of the bar, after the location on wide screens
   and on its own once the location drops out. */
.bar__inner .modes { margin-left: auto; }
.bar__meta + .modes { margin-left: clamp(0.75rem, 2vw, 1.5rem); }

/* Theme icon swap (used inside the rail) ---------------------------------- */

.bar__sun, .bar__rays, .bar__moon {
  transition: opacity 0.35s var(--ease), transform 0.5s var(--ease);
  transform-origin: center;
}
.bar__moon { opacity: 0; transform: rotate(-70deg) scale(0.5); }

:root[data-theme="dark"] .bar__sun,
:root[data-theme="dark"] .bar__rays { opacity: 0; transform: scale(0.4); }
:root[data-theme="dark"] .bar__moon { opacity: 1; transform: none; }

@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) .bar__sun,
  :root:not([data-theme="light"]) .bar__rays { opacity: 0; transform: scale(0.4); }
  :root:not([data-theme="light"]) .bar__moon { opacity: 1; transform: none; }
}

/* ==========================================================================
   Floating rail: a flat cylinder that expands to labels on hover
   ========================================================================== */

.rail {
  position: fixed;
  z-index: 70;
  top: 50%;
  right: clamp(0.75rem, 2vw, 1.75rem);
  transform: translateY(-50%);
}

.rail__pill {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.5rem;
  padding: 0.5rem;
  border: 1px solid var(--rule);
  border-radius: 999px;
  background: var(--paper-raised);
  box-shadow: 0 1px 2px rgba(20, 18, 12, 0.04),
              0 10px 30px -12px rgba(20, 18, 12, 0.22);
  transition: border-color 0.4s var(--ease), box-shadow 0.4s var(--ease);
}

.rail:hover .rail__pill,
.rail:focus-within .rail__pill {
  border-color: var(--rule-strong);
  box-shadow: 0 1px 2px rgba(20, 18, 12, 0.05),
              0 18px 44px -14px rgba(20, 18, 12, 0.3);
}

/* Avatar ---------------------------------------------------------------- */

.rail__avatar {
  position: relative;
  display: block;
  width: 2.5rem;
  height: 2.5rem;
  flex: none;
  border-radius: 50%;
  overflow: visible;
}
.rail__avatar img {
  width: 100%;
  height: 100%;
  border-radius: 50%;
  object-fit: cover;
  transition: transform 0.5s var(--ease);
}
.rail__avatar:hover img { transform: scale(1.06); }

/* Ring that draws itself around the avatar on hover. */
.rail__ring {
  position: absolute;
  inset: -4px;
  border-radius: 50%;
  border: 1px solid var(--accent);
  opacity: 0;
  transform: scale(0.85);
  transition: opacity 0.4s var(--ease), transform 0.5s var(--ease);
}
.rail__avatar:hover .rail__ring,
.rail__avatar:focus-visible .rail__ring { opacity: 1; transform: scale(1); }

.rail__divider {
  width: 1rem;
  height: 1px;
  background: var(--rule);
  flex: none;
}

/* Items ----------------------------------------------------------------- */

.rail__list {
  display: flex;
  flex-direction: column;
  gap: 0.15rem;
  width: 100%;
}

.rail__item {
  position: relative;
  display: flex;
  align-items: center;
  gap: 0.6rem;
  height: 2.5rem;
  padding-inline: 0.7rem;
  border-radius: 999px;
  text-decoration: none;
  color: var(--ink-faint);
  white-space: nowrap;
  transition: color 0.3s var(--ease), background 0.3s var(--ease);
}

.rail__dot {
  width: 5px;
  height: 5px;
  flex: none;
  border-radius: 50%;
  background: currentColor;
  opacity: 0.45;
  transition: opacity 0.3s var(--ease), transform 0.4s var(--ease);
}

/* The number is what shows while collapsed; the label replaces it on expand. */
.rail__num {
  position: absolute;
  left: 0;
  right: 0;
  text-align: center;
  letter-spacing: 0.06em;
  opacity: 0;
  transition: opacity 0.25s var(--ease);
  pointer-events: none;
}

.rail__label {
  font-family: var(--font-mono);
  font-size: var(--t-mono);
  font-weight: 500;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  max-width: 0;
  overflow: hidden;
  opacity: 0;
  transition: max-width 0.45s var(--ease), opacity 0.3s var(--ease);
}

.rail:hover .rail__label,
.rail:focus-within .rail__label { max-width: 7rem; opacity: 1; }

.rail__item.is-current { color: var(--ink); }
.rail__item.is-current .rail__dot {
  opacity: 1;
  background: var(--accent);
  transform: scale(1.35);
}

@media (hover: hover) {
  .rail__item:hover { color: var(--ink); background: var(--paper-sunk); }
  .rail__item:hover .rail__dot { opacity: 1; }
}
.rail__item:focus-visible { color: var(--ink); background: var(--paper-sunk); }

/* Theme toggle ---------------------------------------------------------- */

.rail__theme {
  display: grid;
  place-items: center;
  width: 2.5rem;
  height: 2.5rem;
  flex: none;
  border-radius: 50%;
  color: var(--ink-faint);
  transition: color 0.3s var(--ease), background 0.3s var(--ease);
}
@media (hover: hover) {
  .rail__theme:hover { color: var(--ink); background: var(--paper-sunk); }
}

/* Mobile: the rail becomes a dock at the bottom, in thumb reach ---------- */

@media (max-width: 56rem) {
  .rail {
    top: auto;
    bottom: max(0.75rem, env(safe-area-inset-bottom));
    right: 50%;
    transform: translateX(50%);
  }

  .rail__pill {
    flex-direction: row;
    gap: 0.25rem;
    padding: 0.375rem;
  }

  .rail__list { flex-direction: row; width: auto; gap: 0.1rem; }
  .rail__divider { width: 1px; height: 1.25rem; }

  .rail__avatar { width: 2.25rem; height: 2.25rem; }
  .rail__theme { width: 2.5rem; height: 2.5rem; }

  /* There is no hover on touch, so nothing can expand. Show the labels
     outright, and fall back to numbers only when they genuinely won't fit. */
  .rail__item {
    min-width: 2.75rem;
    height: 2.75rem;
    padding-inline: 0.6rem;
    justify-content: center;
  }
  .rail__dot { display: none; }
  .rail__num { position: static; opacity: 1; }
  .rail__label {
    position: absolute;
    width: 1px; height: 1px;
    overflow: hidden;
    clip-path: inset(50%);
  }
  .rail__item.is-current { background: var(--paper-sunk); color: var(--accent); }
}

@media (max-width: 56rem) and (min-width: 22rem) {
  .rail__num {
    position: absolute;
    width: 1px; height: 1px;
    overflow: hidden;
    clip-path: inset(50%);
    opacity: 1;
  }
  .rail__label {
    position: static;
    width: auto;
    height: auto;
    max-width: none;
    opacity: 1;
    overflow: visible;
    clip-path: none;
  }
}

/* Keep the last section clear of the dock. */
@media (max-width: 56rem) {
  .foot { padding-bottom: calc(clamp(2.5rem, 6vw, 4rem) + 4rem); }
}

@media (prefers-reduced-motion: reduce) {
  .rail__label { transition: none; }
}