/* ==========================================================================
   04 / The One Solution difference (full width)
   Four disciplines clients can pick from in any combination, shown on one
   shared rail, then a plain text comparison with the usual agency setup.
   ========================================================================== */

.diff {
  background: var(--color-white);
}

/* ---- Head ---- */
.diff__head {
  align-items: end;
  row-gap: var(--space-5);
}

.diff__eyebrow {
  grid-column: 1 / -1;
  color: var(--color-gray-500);
}

.diff__title {
  grid-column: 1 / span 8;
  max-width: 18ch;
}

.diff__intro {
  grid-column: 9 / span 4;
  color: var(--color-gray-700);
}

/* Heading highlight: same marker as hero and What We Do */
.diff__mark {
  background-image: linear-gradient(var(--color-brand-blue), var(--color-brand-blue));
  background-repeat: no-repeat;
  background-position: 0 90%;
  background-size: 100% 0.22em;
  transition: background-size 900ms var(--ease-out) 200ms;
}

.js .diff:not(.is-inview) .diff__mark {
  background-size: 0% 0.22em;
}

/* ---- Disciplines ----
   No fixed order: clients can start with any discipline. All four rail
   segments draw in together, so the row reads as one connected whole. */
.diff__flow {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  margin-top: var(--space-11);
  border-top: 1px solid var(--color-gray-200);
}

.diff-step--strategy   { --step-color: var(--color-black); }
.diff-step--brand      { --step-color: var(--color-brand-orange); }
.diff-step--marketing  { --step-color: var(--color-brand-red); }
.diff-step--technology { --step-color: var(--color-brand-blue); }

.diff-step {
  position: relative;
  display: flex;
  flex-direction: column;
  padding: var(--space-7) var(--space-6) 0 0;
}

/* Rail segment in the discipline colour */
.diff-step::before {
  content: "";
  position: absolute;
  top: -1px;
  left: 0;
  right: 0;
  height: 4px;
  background: var(--step-color);
  transform-origin: left;
  transition: transform 900ms var(--ease-out) 300ms;
}

.js .diff:not(.is-inview) .diff-step::before {
  transform: scaleX(0);
}

.diff-step__when {
  max-width: 26ch;
  color: var(--color-gray-500);
}

.diff-step__name {
  margin-top: var(--space-3);
}

.diff-step__text {
  margin-top: var(--space-4);
  max-width: 30ch;
  color: var(--color-gray-700);
}

.diff-step__links {
  margin-top: auto;
  padding-top: var(--space-6);
  font-weight: var(--fw-semibold);
  color: var(--color-black);
}

/* Grey label: brand colours stay on the rail (orange text is unreadable on white) */
.diff-step__links span {
  display: block;
  margin-bottom: var(--space-1);
  font-weight: var(--fw-regular);
  color: var(--color-gray-500);
}

/* Content fades up together with the rail */
.js .diff .diff-step > * {
  transition:
    opacity 700ms var(--ease-out) 450ms,
    transform 700ms var(--ease-out) 450ms;
}

.js .diff:not(.is-inview) .diff-step > * {
  opacity: 0;
  transform: translateY(12px);
}

/* ---- Comparison ---- */
.diff__compare {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: var(--grid-gap);
  margin-top: var(--space-12);
}

.diff-col {
  padding: var(--space-8);
  border-radius: var(--radius-sharp);
}

.diff-col--usual {
  background: var(--color-gray-50);
  border: 1px solid var(--color-gray-200);
}

.diff-col--ours {
  background: var(--color-pitch-black);
  color: var(--color-white);
}

.diff-col__title {
  color: var(--color-gray-500);
}

.diff-col--ours .diff-col__title {
  color: var(--color-brand-orange);
}

.diff-col__list {
  margin-top: var(--space-5);
}

.diff-col__list li {
  padding-block: var(--space-4);
  font-size: var(--fs-body-xl);
  line-height: var(--lh-body-xl);
  border-bottom: 1px solid var(--color-gray-200);
}

.diff-col__list li:last-child {
  border-bottom: 0;
  padding-bottom: 0;
}

.diff-col--usual .diff-col__list li {
  color: var(--color-gray-500);
}

.diff-col--ours .diff-col__list li {
  border-bottom-color: var(--color-gray-900);
}

/* ---- Tablet: 2 x 2 flow ---- */
@media (max-width: 1024px) {
  .diff__title,
  .diff__intro {
    grid-column: 1 / -1;
  }

  .diff__flow {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    row-gap: var(--space-9);
    margin-top: var(--space-10);
    border-top: 0;
  }

  .diff-step {
    border-top: 1px solid var(--color-gray-200);
  }

  .diff__compare {
    grid-template-columns: minmax(0, 1fr);
    margin-top: var(--space-11);
  }

  .diff-col {
    padding: var(--space-7);
  }
}

/* ---- Mobile: vertical flow, rail on the left ---- */
@media (max-width: 640px) {
  .diff__flow {
    grid-template-columns: minmax(0, 1fr);
    row-gap: 0;
    margin-top: var(--space-8);
  }

  .diff-step {
    padding: var(--space-6) 0 var(--space-6) var(--space-5);
    border-top: 0;
  }

  .diff-step::before {
    top: 0;
    bottom: 0;
    right: auto;
    width: 3px;
    height: auto;
    transform-origin: top;
  }

  .js .diff:not(.is-inview) .diff-step::before {
    transform: scaleY(0);
  }

  .diff-step__links {
    padding-top: var(--space-4);
  }

  .diff__compare {
    margin-top: var(--space-10);
  }

  .diff-col {
    padding: var(--space-6) var(--space-5);
  }

  .diff-col__list li {
    font-size: var(--fs-body);
    line-height: var(--lh-body);
  }
}