/* ============================================================
   GLOBAL PORTFOLIO HEADER — shared across every page (home +
   case studies). Depends only on tokens from css/hero.css
   (--mono, --muted, --cyan, --border), so it can be dropped
   into any page right after hero.css.

   Structure:
   - .cs-topbar       the bar itself (empty left side by design)
   - .cs-signature    portfolio identity, absolutely centered on
                       the viewport regardless of what else is
                       in the bar (case studies only, see below)
   - .cs-back         "‹ BACK TO PROJECTS" — case-study pages only,
                       omitted entirely on the homepage
   ============================================================ */

.cs-topbar {
  position: relative;
  z-index: 2;
  max-width: 1540px;
  margin: 0 auto;
  padding: 20px 32px;
  min-height: 84px;
  display: flex;
  align-items: center;
  justify-content: flex-end;
  gap: 16px;
}

/* ---- portfolio signature: absolutely centered on the viewport,
   independent of the (empty) left side and the back-button width ---- */
.cs-signature {
  position: absolute;
  left: 50%;
  top: 50%;
  transform: translate(-50%, -50%);
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--muted);
  white-space: nowrap;
}

.cs-signature-short { display: none; }

/* below this width the full signature would collide with the
   fixed-width back-projects control — swap to the short form */
@media (max-width: 860px) {
  .cs-signature-full { display: none; }
  .cs-signature-short { display: inline; }
}

/* below this width the fixed-width back-projects button is wide enough
   that even the short signature can't stay truly viewport-centered
   without touching it — fall back to centering within the remaining
   space instead (still one line, still centered, never overlapping) */
@media (max-width: 700px) {
  .cs-signature {
    position: static;
    left: auto;
    top: auto;
    transform: none;
    flex: 1 1 auto;
    min-width: 0;
    text-align: center;
    overflow: hidden;
    text-overflow: ellipsis;
  }

  /* the signature now shares the flex row — keep the button's own
     size fixed so it can never be squeezed into wrapping */
  .cs-back { flex-shrink: 0; }
}

.cs-back {
  display: inline-flex;
  align-items: center;
  gap: 9px;
  font-family: var(--mono);
  font-size: 10px;
  letter-spacing: 0.16em;
  padding: 10px 18px;
  border-radius: 100px;
  border: 1px solid var(--border);
  background: rgba(140, 180, 255, 0.02);
  color: var(--muted);
  text-decoration: none;
  transition: all 0.25s;
}

.cs-back:hover {
  color: var(--cyan);
  border-color: rgba(56, 189, 248, 0.4);
  background: rgba(56, 189, 248, 0.05);
}

@media (max-width: 1080px) {
  .cs-topbar { padding: 16px; min-height: 76px; }
}