/* Installation process, method comparison, stair diagram, and prep flows.
   Scoped to .fx-install. Square corners, hairlines, one oak mark. */

.fx-run,
.fx-asm-wrap,
.fx-flow-block,
.fx-stair-block {
  --fx-ink: #1c1a17;
  --fx-ink-soft: #4a453e;
  --fx-stone: #766e64;
  --fx-line: #e2dbcf;
  --fx-linen: #f5f1ea;
  --fx-paper: #fbf9f5;
  --fx-sand: #ede6da;
  --fx-oak: #b08a5b;
  --fx-oak-deep: #8c6a43;
  --fx-ease: cubic-bezier(0.22, 1, 0.36, 1);
}

.fx-run { padding: var(--fx-section) 0; }
.fx-run--paper { background: var(--fx-paper); }

.fx-run__board {
  position: relative;
  margin-top: 48px;
}

.fx-run__rail {
  position: absolute;
  left: 15px;
  top: 8px;
  bottom: 8px;
  width: 1px;
  background: var(--fx-line);
}

.fx-run__fill {
  display: block;
  width: 1px;
  height: 100%;
  background: var(--fx-oak);
  transform: scaleY(0.2);
  transform-origin: top center;
  transition: transform 520ms var(--fx-ease);
}

.fx-run__steps {
  list-style: none;
  margin: 0;
  padding: 0;
}

.fx-run__step {
  position: relative;
  padding: 0 0 36px 52px;
}

.fx-run__step:last-child { padding-bottom: 0; }

.fx-run__step button {
  display: grid;
  grid-template-columns: auto 1fr;
  column-gap: 16px;
  align-items: baseline;
  width: 100%;
  margin: 0;
  padding: 0;
  border: 0;
  background: none;
  color: inherit;
  font: inherit;
  text-align: left;
  cursor: pointer;
}

.fx-run__step button:focus-visible {
  outline: 2px solid var(--fx-oak);
  outline-offset: 6px;
}

.fx-run__n {
  color: var(--fx-oak);
  font-size: 13px;
  font-variant-numeric: tabular-nums;
  letter-spacing: 0.14em;
}

.fx-run__name {
  font-family: var(--fx-serif);
  font-weight: 300;
  font-size: clamp(26px, 2.4vw, 36px);
  letter-spacing: -0.02em;
  line-height: 1.1;
  color: var(--fx-stone);
  transition: color 320ms var(--fx-ease);
}

.fx-run__step.is-on .fx-run__name { color: var(--fx-ink); }

.fx-run__step button::before {
  content: "";
  position: absolute;
  left: 11px;
  top: 0.55em;
  width: 9px;
  height: 9px;
  background: var(--fx-linen);
  border: 1px solid var(--fx-oak);
  transition: background 320ms var(--fx-ease);
}

.fx-run--paper .fx-run__step button::before { background: var(--fx-paper); }
.fx-run__step.is-on button::before { background: var(--fx-oak); }

.fx-run__body {
  margin: 12px 0 0;
  max-width: 62ch;
  color: var(--fx-ink-soft);
  font-size: 17px;
  line-height: 1.65;
}

.fx-run__detail { display: none; }

@media (min-width: 900px) {
  .fx-run__board {
    display: grid;
    grid-template-columns: minmax(240px, 0.72fr) 1.28fr;
    column-gap: 72px;
    align-items: start;
  }
  .fx-run__rail { display: none; }
  .fx-run__steps {
    display: flex;
    flex-direction: column;
    border-top: 1px solid var(--fx-line);
  }
  .fx-run__step {
    padding: 0;
    border-bottom: 1px solid var(--fx-line);
  }
  .fx-run__step button {
    grid-template-columns: 36px 1fr;
    padding: 18px 8px;
  }
  .fx-run__step button::before { display: none; }
  .fx-run__name { font-size: clamp(22px, 1.7vw, 28px); }
  .fx-run__step.is-on .fx-run__name { font-size: clamp(28px, 2.2vw, 36px); }
  .fx-run__board.is-ready .fx-run__body {
    display: none;
    margin: 0;
  }
  .fx-run__detail {
    display: block;
    position: sticky;
    top: 112px;
    padding-top: 8px;
  }
  .fx-run__detail h3 {
    margin: 0;
    font-family: var(--fx-serif);
    font-weight: 300;
    font-size: clamp(36px, 3.2vw, 52px);
    letter-spacing: -0.02em;
    line-height: 1.05;
  }
  .fx-run__detail p {
    margin: 18px 0 0;
    max-width: 42ch;
    color: var(--fx-ink-soft);
    font-size: 18px;
    line-height: 1.6;
  }
}

/* Method cross-section */
.fx-asm { margin-top: 56px; }

.fx-asm__tabs {
  display: flex;
  flex-wrap: wrap;
  gap: 0;
  border-bottom: 1px solid var(--fx-line);
}

.fx-asm__tabs button {
  margin: 0;
  padding: 14px 18px 16px;
  border: 0;
  border-bottom: 1px solid transparent;
  margin-bottom: -1px;
  background: none;
  color: var(--fx-stone);
  font: inherit;
  font-size: 15px;
  cursor: pointer;
}

.fx-asm__tabs button[aria-selected="true"] {
  color: var(--fx-ink);
  border-bottom-color: var(--fx-oak);
}

.fx-asm__tabs button:focus-visible {
  outline: 2px solid var(--fx-oak);
  outline-offset: 3px;
}

.fx-asm__stage {
  display: grid;
  gap: 28px;
  margin-top: 28px;
}

.fx-asm__svg {
  width: 100%;
  height: auto;
  background: var(--fx-sand);
  display: block;
}

.fx-asm__scene { opacity: 0; }
.fx-asm:not([data-method])[data-start="glue"] .fx-asm__scene[data-method="glue"],
.fx-asm:not([data-method])[data-start="assist"] .fx-asm__scene[data-method="assist"],
.fx-asm:not([data-method])[data-start="nail"] .fx-asm__scene[data-method="nail"],
.fx-asm:not([data-method])[data-start="float"] .fx-asm__scene[data-method="float"],
.fx-asm[data-method="glue"] .fx-asm__scene[data-method="glue"],
.fx-asm[data-method="assist"] .fx-asm__scene[data-method="assist"],
.fx-asm[data-method="nail"] .fx-asm__scene[data-method="nail"],
.fx-asm[data-method="float"] .fx-asm__scene[data-method="float"] {
  opacity: 1;
}

.fx-asm__svg text,
.fx-flow__svg text,
.fx-stair__svg text {
  font-family: "Inter Tight", "Segoe UI", sans-serif;
}
.fx-asm__tag {
  font-family: "Inter Tight", "Segoe UI", sans-serif;
  font-size: 12px;
  letter-spacing: 0.14em;
  fill: #4a453e;
}

.fx-asm__panels { position: relative; min-height: 12rem; }

.fx-asm.is-ready .fx-asm__panel { display: none; }
.fx-asm.is-ready .fx-asm__panel.is-on { display: block; }

.fx-asm__panel h3 {
  margin: 0;
  font-family: var(--fx-serif);
  font-weight: 300;
  font-size: clamp(28px, 2.6vw, 40px);
  letter-spacing: -0.02em;
  line-height: 1.08;
}

.fx-asm__panel p {
  margin: 14px 0 0;
  max-width: 58ch;
  color: var(--fx-ink-soft);
  font-size: 17px;
  line-height: 1.65;
}

.fx-asm__facts {
  margin: 22px 0 0;
  border-top: 1px solid var(--fx-line);
}

.fx-asm__facts div {
  display: grid;
  grid-template-columns: minmax(108px, 160px) 1fr;
  gap: 8px 16px;
  padding: 12px 0;
  border-bottom: 1px solid var(--fx-line);
}

.fx-asm__facts dt {
  margin: 0;
  color: var(--fx-stone);
  font-size: 13px;
  letter-spacing: 0.12em;
  text-transform: uppercase;
}

.fx-asm__facts dd { margin: 0; color: var(--fx-ink); }

.fx-asm__panel .fx-link { display: inline-block; margin-top: 18px; }

@media (min-width: 900px) {
  .fx-asm__stage {
    grid-template-columns: 1.15fr 0.85fr;
    column-gap: 56px;
    align-items: center;
  }
}

/* Prep flows */
.fx-flow { margin-top: 40px; }

.fx-flow__track {
  display: flex;
  gap: 0;
  list-style: none;
  margin: 0;
  padding: 0;
  overflow-x: auto;
  border-top: 1px solid var(--fx-line);
  border-bottom: 1px solid var(--fx-line);
}

.fx-flow__track li { flex: 1 0 auto; }

.fx-flow__track button {
  width: 100%;
  margin: 0;
  padding: 16px 14px;
  border: 0;
  background: none;
  color: var(--fx-stone);
  font: inherit;
  font-size: 14px;
  text-align: left;
  cursor: pointer;
  white-space: nowrap;
}

.fx-flow__track button[aria-current="step"] {
  color: var(--fx-ink);
  box-shadow: inset 0 -1px 0 var(--fx-oak);
}

.fx-flow__track button:focus-visible {
  outline: 2px solid var(--fx-oak);
  outline-offset: -2px;
}

.fx-flow__scene {
  margin-top: 28px;
  background: var(--fx-sand);
  min-height: 220px;
  position: relative;
  overflow: hidden;
}

.fx-flow__svg { width: 100%; height: auto; display: block; }

.fx-flow__frame { opacity: 0; transition: opacity 420ms var(--fx-ease); }
.fx-flow:not([data-step]) .fx-flow__frame[data-from="1"] { opacity: 1; }
.fx-flow:not(.is-ready) .fx-flow__panel + .fx-flow__panel { display: none; }
.fx-asm:not(.is-ready) .fx-asm__panel + .fx-asm__panel { display: none; }
.fx-flow[data-step="1"] .fx-flow__frame[data-from="1"],
.fx-flow[data-step="2"] .fx-flow__frame[data-from="2"],
.fx-flow[data-step="3"] .fx-flow__frame[data-from="3"],
.fx-flow[data-step="4"] .fx-flow__frame[data-from="4"],
.fx-flow[data-step="5"] .fx-flow__frame[data-from="5"] { opacity: 1; }

.fx-flow__read { margin-top: 22px; max-width: 62ch; }
.fx-flow__read h3 {
  margin: 0;
  font-family: var(--fx-serif);
  font-weight: 300;
  font-size: clamp(28px, 2.6vw, 40px);
  letter-spacing: -0.02em;
  line-height: 1.08;
}
.fx-flow__read p {
  margin: 12px 0 0;
  color: var(--fx-ink-soft);
  font-size: 17px;
  line-height: 1.65;
}
.fx-flow.is-ready .fx-flow__panel { display: none; }
.fx-flow.is-ready .fx-flow__panel.is-on { display: block; }

/* Stair schematic */
.fx-stair { margin-top: 36px; }

.fx-stair__svg {
  width: 100%;
  height: auto;
  background: var(--fx-sand);
  display: block;
}

.fx-stair__part { cursor: pointer; }
.fx-stair__part.is-on .fx-stair__hit {
  stroke: var(--fx-oak);
  stroke-width: 2;
}
.fx-stair__part:focus-visible { outline: none; }
.fx-stair__part:focus-visible .fx-stair__hit { stroke: var(--fx-oak); stroke-width: 2; }

.fx-stair__picks {
  display: flex;
  flex-wrap: wrap;
  gap: 0;
  margin-top: 0;
  border-bottom: 1px solid var(--fx-line);
}

.fx-stair__picks button {
  margin: 0;
  padding: 12px 14px;
  border: 0;
  background: none;
  color: var(--fx-stone);
  font: inherit;
  font-size: 14px;
  cursor: pointer;
}

.fx-stair__picks button[aria-pressed="true"] {
  color: var(--fx-ink);
  box-shadow: inset 0 -1px 0 var(--fx-oak);
}

.fx-stair__picks button:focus-visible {
  outline: 2px solid var(--fx-oak);
  outline-offset: 2px;
}

.fx-stair__read { margin-top: 22px; max-width: 62ch; }
.fx-stair__read h3 {
  margin: 0;
  font-family: var(--fx-serif);
  font-weight: 300;
  font-size: clamp(28px, 2.4vw, 40px);
  letter-spacing: -0.02em;
}
.fx-stair__read p {
  margin: 12px 0 0;
  color: var(--fx-ink-soft);
  font-size: 17px;
  line-height: 1.65;
}

@media (prefers-reduced-motion: reduce) {
  .fx-run__fill,
  .fx-run__name,
  .fx-flow__frame,
  .fx-asm__scene {
    transition: none;
  }
}