/* ==========================================================================
   CHROME - rail nav, topbar, menu, theme switch, cursor, footer.
   ========================================================================== */

/* --------------------------------------------------------------------------
   Pulse dot - "this is live"
   -------------------------------------------------------------------------- */

.pulse-dot {
  position: relative;
  display: inline-block;
  width: 6px; height: 6px;
  border-radius: 50%;
  background: var(--copper);
  flex: none;
  vertical-align: 1px;
}

.pulse-dot::after {
  content: '';
  position: absolute;
  inset: -3px;
  border-radius: 50%;
  border: 1px solid var(--copper);
  opacity: 0;
  animation: pulse-ring 2.6s var(--ease-out) infinite;
}

@keyframes pulse-ring {
  0%   { transform: scale(0.5); opacity: 0.9; }
  70%  { transform: scale(2.1); opacity: 0; }
  100% { transform: scale(2.1); opacity: 0; }
}

@media (prefers-reduced-motion: reduce) {
  .pulse-dot::after { animation: none; opacity: .35; }
}

/* ==========================================================================
   RAIL - desktop navigation as a signal trace
   ========================================================================== */

.rail { display: none; }

@media (min-width: 900px) {
  .rail {
    position: fixed;
    inset-block: 0;
    left: 0;
    width: var(--rail);
    z-index: 60;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: space-between;
    padding-block: var(--sp-6);
    border-right: 1px solid var(--line);
    background: linear-gradient(90deg, var(--bg-sunk), transparent);
    backdrop-filter: blur(6px);
  }
}

/* Monogram ---------------------------------------------------------------- */

.rail__mark {
  width: 40px; height: 40px;
  flex: none;
  border-radius: 50%;
  display: grid;
  place-items: center;
  transition: transform var(--dur-3) var(--ease-spring);
}

.rail__mark:hover { transform: rotate(-8deg) scale(1.06); }

.rail__mark svg { width: 100%; height: 100%; overflow: visible; }

.rail__mark-ring {
  fill: none;
  stroke: var(--line-2);
  stroke-width: 1;
  transition: stroke var(--dur-3) var(--ease-out);
}

.rail__mark-glyph {
  fill: none;
  stroke: var(--ink);
  stroke-width: 2.4;
  stroke-linecap: round;
  transition: stroke var(--dur-3) var(--ease-out);
}

.rail__mark:hover .rail__mark-ring  { stroke: var(--copper); }
.rail__mark:hover .rail__mark-glyph { stroke: var(--copper); }

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

.rail__list {
  list-style: none;
  margin: 0; padding: 0;
  display: flex;
  flex-direction: column;
  gap: clamp(var(--sp-6), 4.4vh, var(--sp-8));
  position: relative;
  z-index: 2;
}

.rail__item {
  position: relative;
  display: grid;
  place-items: center;
  width: 44px; height: 22px;
  text-decoration: none;
}

.rail__via {
  width: 9px; height: 9px;
  border-radius: 50%;
  background: var(--bg);
  border: 1.5px solid var(--ink-4);
  transition:
    border-color var(--dur-3) var(--ease-out),
    background-color var(--dur-3) var(--ease-out),
    transform var(--dur-3) var(--ease-spring),
    box-shadow var(--dur-3) var(--ease-out);
}

.rail__no {
  position: absolute;
  right: calc(50% + 13px);
  font-family: var(--font-mono);
  font-size: 9.5px;
  font-weight: 500;
  letter-spacing: 0.04em;
  color: var(--ink-4);
  font-variant-numeric: tabular-nums;
  transition: color var(--dur-3) var(--ease-out);
}

.rail__label {
  position: absolute;
  left: calc(50% + 15px);
  padding: 5px 11px;
  border: 1px solid var(--line-2);
  border-radius: 99px;
  background: var(--surface);
  box-shadow: var(--shadow-1);
  font-family: var(--font-mono);
  font-size: var(--step--2);
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--ink);
  white-space: nowrap;
  opacity: 0;
  transform: translateX(-6px);
  pointer-events: none;
  transition:
    opacity var(--dur-2) var(--ease-out),
    transform var(--dur-3) var(--ease-expo);
}

.rail__item:hover  .rail__via,
.rail__item:focus-visible .rail__via { border-color: var(--copper); transform: scale(1.25); }
.rail__item:hover  .rail__no,
.rail__item:focus-visible .rail__no  { color: var(--ink-2); }
.rail__item:hover  .rail__label,
.rail__item:focus-visible .rail__label { opacity: 1; transform: translateX(0); }

.rail__item.is-current .rail__via {
  border-color: var(--copper);
  background: var(--copper);
  box-shadow: 0 0 0 3px var(--copper-wash), 0 0 14px var(--copper-wash);
}

.rail__item.is-current .rail__no { color: var(--copper); }

/* The trace the vias sit on, and the charge that climbs it. */
.rail__trace {
  position: absolute;
  top: 0; bottom: 0;
  left: 50%;
  width: 1px;
  transform: translateX(-0.5px);
  background: var(--line);
  z-index: 1;
  overflow: hidden;
}

.rail__trace-fill {
  position: absolute;
  inset-inline: 0;
  top: 0;
  height: 0;
  background: linear-gradient(180deg, var(--copper-lo), var(--copper));
  transition: height 120ms linear;
}

.rail__trace-fill::after {
  content: '';
  position: absolute;
  left: -2px; right: -2px;
  bottom: 0;
  height: 26px;
  background: linear-gradient(180deg, transparent, var(--copper-hi));
  filter: blur(2px);
  opacity: .75;
}

/* --------------------------------------------------------------------------
   Theme switch - a slide switch off a board
   -------------------------------------------------------------------------- */

.theme-toggle {
  background: none;
  border: 0;
  padding: var(--sp-2);
  cursor: pointer;
  display: grid;
  place-items: center;
  flex: none;
}

.theme-toggle__track {
  position: relative;
  display: block;
  width: 20px; height: 34px;
  border: 1px solid var(--line-2);
  border-radius: 99px;
  background: var(--surface);
  transition: border-color var(--dur-2) var(--ease-out),
              background-color var(--dur-3) var(--ease-out);
}

.theme-toggle__knob {
  position: absolute;
  left: 50%;
  top: 3px;
  width: 12px; height: 12px;
  margin-left: -6px;
  border-radius: 50%;
  background: var(--copper);
  box-shadow: 0 0 10px var(--copper-wash);
  transition: transform var(--dur-3) var(--ease-spring),
              background-color var(--dur-3) var(--ease-out);
}

[data-theme='light'] .theme-toggle__knob { transform: translateY(16px); background: var(--signal); }

.theme-toggle:hover .theme-toggle__track { border-color: var(--copper); }

/* ==========================================================================
   SCROLL PROGRESS - mobile only; on desktop the rail trace already shows it
   ========================================================================== */

.scroll-progress {
  position: fixed;
  top: 0;
  inset-inline: 0;
  height: 2px;
  z-index: 75;
  pointer-events: none;
  background: transparent;
}

.scroll-progress__fill {
  display: block;
  height: 100%;
  background: linear-gradient(90deg, var(--copper-lo), var(--copper));
  transform: scaleX(0);
  transform-origin: 0 50%;
  will-change: transform;
}

@media (min-width: 900px) {
  .scroll-progress { display: none; }
}

.rail__tools {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: var(--sp-2);
  margin-bottom: var(--sp-2);
}

/* ==========================================================================
   TOAST - transient confirmation for actions with no visible result
   ========================================================================== */

.toast {
  position: fixed;
  left: 50%;
  bottom: var(--sp-6);
  z-index: 300;
  transform: translate(-50%, 12px);
  padding: 0.7rem 1.1rem;
  border: 1px solid color-mix(in srgb, var(--copper) 35%, transparent);
  border-radius: 99px;
  background: var(--surface);
  box-shadow: var(--shadow-2);
  font-family: var(--font-mono);
  font-size: var(--step--2);
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--copper);
  opacity: 0;
  pointer-events: none;
  transition: opacity var(--dur-2) var(--ease-out),
              transform var(--dur-3) var(--ease-out);
}

.toast.is-on { opacity: 1; transform: translate(-50%, 0); }

/* ==========================================================================
   TOPBAR + MENU - under 900px
   ========================================================================== */

.topbar {
  position: fixed;
  top: 0; inset-inline: 0;
  z-index: 70;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--sp-4);
  padding: var(--sp-3) var(--gutter);
  background: var(--surface-glass);
  backdrop-filter: blur(14px) saturate(1.3);
  border-bottom: 1px solid transparent;
  transition: border-color var(--dur-3) var(--ease-out),
              background-color var(--dur-3) var(--ease-out);
}

.topbar.is-stuck { border-bottom-color: var(--line); }

@media (min-width: 900px) { .topbar { display: none; } }

.topbar__mark {
  display: flex;
  align-items: baseline;
  gap: var(--sp-3);
  text-decoration: none;
  min-width: 0;
}

.topbar__mono {
  font-family: var(--font-display);
  font-size: var(--step-1);
  font-variation-settings: 'SOFT' 0, 'WONK' 1, 'opsz' 40;
  letter-spacing: -0.02em;
  color: var(--ink);
}

.topbar__status {
  font-family: var(--font-mono);
  font-size: var(--step--2);
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--ink-3);
  display: inline-flex;
  align-items: center;
  gap: 6px;
  white-space: nowrap;
}

.topbar__actions { display: flex; align-items: center; gap: var(--sp-2); }

/* The theme switch is a vertical slide-switch on the desktop rail, where it
   has a column to sit in. In the top bar it shares a horizontal row with the
   menu button, and at 50px tall against their 34px it made the whole row
   look misaligned. Here it lies down and matches its neighbour. */
.topbar .theme-toggle { padding: 0; }

.topbar .theme-toggle__track {
  width: 42px;
  height: 34px;
  border-radius: 99px;
  display: grid;
  place-items: center;
}

.topbar .theme-toggle__knob {
  position: static;
  margin: 0;
  width: 13px;
  height: 13px;
  transform: none;
}

[data-theme='light'] .topbar .theme-toggle__knob { transform: none; }

.menu-btn {
  background: none;
  border: 1px solid var(--line-2);
  border-radius: 99px;
  width: 42px; height: 34px;
  display: grid;
  place-items: center;
  cursor: pointer;
  transition: border-color var(--dur-2) var(--ease-out);
}

.menu-btn:hover { border-color: var(--copper); }

.menu-btn__bars { display: grid; gap: 5px; width: 16px; }

.menu-btn__bars i {
  display: block;
  height: 1.5px;
  background: var(--ink);
  border-radius: 2px;
  transition: transform var(--dur-3) var(--ease-expo),
              opacity var(--dur-2) var(--ease-out);
}

.menu-btn[aria-expanded='true'] .menu-btn__bars i:first-child { transform: translateY(3.25px) rotate(45deg); }
.menu-btn[aria-expanded='true'] .menu-btn__bars i:last-child  { transform: translateY(-3.25px) rotate(-45deg); }

/* Overlay ----------------------------------------------------------------- */

.menu {
  position: fixed;
  inset: 0;
  z-index: 65;
  background: var(--bg);
  display: flex;
  flex-direction: column;
  justify-content: center;
  gap: var(--sp-8);
  padding: var(--sp-10) var(--gutter) var(--sp-8);
  opacity: 0;
  transition: opacity var(--dur-3) var(--ease-out);
}

.menu[hidden] { display: none; }
.menu.is-open { opacity: 1; }

.menu__list { list-style: none; margin: 0; padding: 0; display: grid; gap: var(--sp-2); }

.menu__list a {
  display: flex;
  align-items: baseline;
  gap: var(--sp-4);
  padding: var(--sp-3) 0;
  font-family: var(--font-display);
  font-size: var(--step-5);
  font-variation-settings: 'SOFT' 0, 'WONK' 1, 'opsz' 72;
  letter-spacing: -0.03em;
  text-decoration: none;
  color: var(--ink);
  border-bottom: 1px solid var(--line);
  opacity: 0;
  transform: translateY(14px);
  transition: color var(--dur-2) var(--ease-out);
}

.menu.is-open .menu__list a {
  animation: menu-in var(--dur-4) var(--ease-expo) forwards;
  animation-delay: calc(var(--n, 0) * 55ms + 60ms);
}

@keyframes menu-in { to { opacity: 1; transform: none; } }

.menu__list a:hover { color: var(--copper); }

.menu__no {
  font-family: var(--font-mono);
  font-size: var(--step--2);
  letter-spacing: 0.14em;
  color: var(--copper);
  font-variant-numeric: tabular-nums;
}

.menu__foot { text-align: center; font-family: var(--font-mono); font-size: var(--step--1); }

@media (prefers-reduced-motion: reduce) {
  .menu__list a { opacity: 1; transform: none; }
  .menu.is-open .menu__list a { animation: none; }
}

/* ==========================================================================
   CURSOR - added by JS only, desktop fine pointers only
   ========================================================================== */

.cursor { display: none; }

@media (hover: hover) and (pointer: fine) and (prefers-reduced-motion: no-preference) {
  .has-cursor .cursor {
    display: block;
    position: fixed;
    top: 0; left: 0;
    z-index: 200;
    pointer-events: none;
    mix-blend-mode: difference;
    opacity: 0;
    transition: opacity var(--dur-2) var(--ease-out);
  }

  .cursor.is-awake { opacity: 1; }

  .has-cursor { cursor: none; }
  .has-cursor a, .has-cursor button, .has-cursor [role='button'] { cursor: none; }

  .cursor__dot,
  .cursor__ring {
    position: absolute;
    top: 0; left: 0;
    border-radius: 50%;
    will-change: transform;
  }

  .cursor__dot {
    width: 5px; height: 5px;
    margin: -2.5px 0 0 -2.5px;
    background: #fff;
  }

  .cursor__ring {
    width: 30px; height: 30px;
    margin: -15px 0 0 -15px;
    border: 1px solid rgba(255, 255, 255, .55);
    transition: width var(--dur-2) var(--ease-out),
                height var(--dur-2) var(--ease-out),
                margin var(--dur-2) var(--ease-out),
                border-color var(--dur-2) var(--ease-out),
                background-color var(--dur-2) var(--ease-out);
  }

  .cursor.is-hot .cursor__ring {
    width: 52px; height: 52px;
    margin: -26px 0 0 -26px;
    background: rgba(255, 255, 255, .12);
    border-color: rgba(255, 255, 255, .8);
  }

  .cursor.is-down .cursor__ring { width: 22px; height: 22px; margin: -11px 0 0 -11px; }
}

/* ==========================================================================
   FOOTER
   ========================================================================== */

.foot {
  padding-left: var(--rail);
  border-top: 1px solid var(--line);
  background: var(--bg-sunk);
}

.foot__inner {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: var(--sp-4);
  padding-block: var(--sp-6);
}

.foot__inner .label { color: var(--ink-4); }
.foot__mid { flex: 1 1 auto; text-align: center; }

.webring {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: var(--sp-2);
}

.webring--top {
  position: absolute;
  top: var(--sp-4);
  right: var(--gutter);
  z-index: 65;
  padding: 2px;
  border: 1px solid var(--line);
  border-radius: var(--radius-sm);
  background: var(--surface-glass);
  backdrop-filter: blur(14px) saturate(1.3);
}

.webring__nav,
.webring__home {
  display: inline-grid;
  width: 32px;
  height: 32px;
  place-items: center;
  color: var(--ink-3);
  text-decoration: none;
  transition: color 120ms var(--ease-out), background-color 120ms var(--ease-out);
}

.webring__nav {
  font-family: var(--font-mono);
  font-size: 1rem;
}

.webring__home img {
  display: block;
  width: 24px;
  height: 24px;
  object-fit: contain;
  opacity: .88;
  transition: opacity 120ms var(--ease-out), transform 120ms var(--ease-out);
}

.webring__nav:hover,
.webring__home:hover { color: var(--copper); background: var(--copper-wash); }
.webring__home:hover img { opacity: 1; transform: scale(1.08); }

.webring__nav:focus-visible,
.webring__home:focus-visible {
  outline: 2px solid var(--copper);
  outline-offset: 2px;
}

@media (max-width: 899px) {
  .webring--top {
    top: var(--sp-3);
    right: auto;
    left: 50%;
    z-index: 72;
    gap: 2px;
    padding: 0;
    transform: translateX(-50%);
  }

  .webring--top .webring__nav,
  .webring--top .webring__home { width: 28px; height: 34px; }
}

@media (max-width: 560px) {
  .topbar__status { display: none; }
}

@media (max-width: 720px) {
  .foot__inner { flex-direction: column; text-align: center; gap: var(--sp-3); }
  .foot__mid { text-align: center; }
}