/* ============ SECTION RHYTHM ============ */
.section {
  position: relative;
  padding-block: var(--section-y);
  padding-left: var(--gutter);
}

.section--tight {
  padding-block: clamp(64px, 8vh, 120px);
}

.section-head {
  display: flex;
  flex-direction: column;
  gap: var(--sp-2);
  margin-bottom: var(--sp-5);
  max-width: 46ch;
}

.page-body {
  position: relative;
}

/* ============ THE SPINE ============ */
/* A single 1px vertical line runs down the left gutter of the whole page.
   Each section attaches to it with a short horizontal branch + node.
   Dormant -> Lit is permanent (never reverses) as the user scrolls. */

.spine-track {
  position: absolute;
  left: var(--gutter);
  top: 0;
  bottom: 0;
  width: 1px;
  background: var(--line);
  z-index: var(--z-spine);
  pointer-events: none;
}

.spine-track::after {
  content: "";
  position: absolute;
  left: 0;
  top: 0;
  width: 100%;
  height: calc(var(--spine-progress, 0) * 100%);
  background: var(--signal);
  box-shadow: 0 0 8px var(--signal-glow);
  transition: height 60ms linear;
}

.spine-node {
  position: absolute;
  left: var(--gutter);
  transform: translate(-50%, -50%);
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--line);
  border: 1px solid var(--line);
  z-index: calc(var(--z-spine) + 1);
  pointer-events: none;
  transition: background var(--dur-slow) var(--ease), box-shadow var(--dur-slow) var(--ease),
    border-color var(--dur-slow) var(--ease);
}

.spine-node.is-lit {
  background: var(--signal);
  border-color: var(--signal);
  box-shadow: 0 0 10px 2px var(--signal-glow);
}

.spine-branch {
  position: absolute;
  left: var(--gutter);
  width: var(--sp-3);
  height: 1px;
  background: var(--line);
  transform: translateY(-0.5px);
  z-index: var(--z-spine);
  pointer-events: none;
  transition: background var(--dur-slow) var(--ease);
}

.spine-branch.is-lit {
  background: var(--signal);
}

.spine-anchor {
  position: relative;
}

@media (max-width: 767px) {
  .spine-track,
  .spine-node,
  .spine-branch {
    left: var(--gutter);
  }
  .section {
    padding-left: calc(var(--gutter) + var(--sp-2));
  }
  .br-md {
    display: none;
  }
}

/* ============ GRID SYSTEMS ============ */
.grid-services {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--sp-3);
}

.grid-approach {
  display: grid;
  grid-template-columns: 1fr auto 1fr;
  align-items: center;
  gap: var(--sp-5);
}

.pipeline {
  display: flex;
  justify-content: space-between;
  gap: var(--sp-2);
}

.process-row {
  display: grid;
  grid-template-columns: repeat(6, 1fr);
  gap: var(--sp-3);
}

.contact-grid {
  display: grid;
  grid-template-columns: 5fr 7fr;
  gap: var(--sp-6);
  align-items: start;
}

.contact-grid > * {
  min-width: 0;
}

.diff-stack {
  display: flex;
  flex-direction: column;
  gap: var(--sp-4);
}

@media (max-width: 1023px) {
  .grid-services {
    grid-template-columns: repeat(2, 1fr);
  }
  .process-row {
    grid-template-columns: repeat(3, 1fr);
  }
  .contact-grid {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 767px) {
  .grid-services {
    grid-template-columns: 1fr;
  }
  .grid-approach {
    grid-template-columns: 1fr;
    justify-items: center;
    text-align: center;
    gap: var(--sp-4);
  }
  .process-row {
    grid-template-columns: 1fr;
  }
  .pipeline {
    flex-direction: column;
    align-items: flex-start;
  }
  .pipeline-connector {
    flex: none;
    width: 1px;
    height: 20px;
    margin-top: 0;
    margin-left: 4px;
  }
}