/* ══════════════════════════════════════════════════════
   System Architecture page — extends vibe-coding-courses.css.
   Only the Tools-by-Category sub-section needs new styles.
   ══════════════════════════════════════════════════════ */

/* ── Tools section: secondary nav of category jumps ── */
.sa-cat-nav {
  display: flex;
  flex-wrap: wrap;
  gap: .5rem;
  margin: 1.5rem 0 3rem;
  padding: 1rem 1.25rem;
  background: rgba(0,212,255,.02);
  border: 1px solid rgba(0,212,255,.06);
}
.sa-cat-nav-link {
  font-family: var(--heading);
  font-size: .6rem;
  letter-spacing: .12em;
  text-transform: uppercase;
  color: var(--mid);
  text-decoration: none;
  padding: .45rem .85rem;
  border: 1px solid rgba(0,212,255,.12);
  transition: color .2s, border-color .2s, background .2s;
  white-space: nowrap;
}
.sa-cat-nav-link:hover {
  color: var(--white);
  border-color: rgba(0,212,255,.3);
}
.sa-cat-nav-link.is-active {
  color: var(--cyan);
  border-color: rgba(0,212,255,.4);
  background: rgba(0,212,255,.05);
}

/* ── Each category section ── */
.sa-category {
  margin-bottom: 4rem;
  scroll-margin-top: 120px; /* leaves room for the sticky TOC when deep-linked */
}
.sa-category-name {
  font-family: var(--heading);
  font-size: clamp(1.05rem, 2vw, 1.35rem);
  color: var(--white);
  letter-spacing: .02em;
  margin: 0 0 1rem;
  padding-bottom: .65rem;
  border-bottom: 1px solid rgba(0,212,255,.08);
  position: relative;
}
.sa-category-name::after {
  content: '';
  position: absolute;
  bottom: -1px;
  left: 0;
  width: 40px;
  height: 1px;
  background: var(--cyan);
}
.sa-category-intro {
  font-size: 1rem;
  line-height: 1.8;
  color: var(--light);
  max-width: 720px;
  margin: 0 0 1.75rem;
}

/* ── Tool list inside a category ── */
.sa-tool-list {
  list-style: none;
  padding: 0;
  margin: 0;
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  column-gap: 2.5rem;
}
.sa-tool {
  padding: 1rem 0;
  border-bottom: 1px solid rgba(0,212,255,.05);
  font-size: .92rem;
  color: var(--light);
  line-height: 1.6;
}
.sa-tool:last-child { border-bottom: none }
.sa-tool-link {
  font-family: var(--heading);
  font-size: .78rem;
  letter-spacing: .04em;
  text-transform: uppercase;
  color: var(--white);
  text-decoration: none;
  margin-right: .65rem;
  transition: color .2s;
  display: inline-block;
}
.sa-tool-link:hover { color: var(--cyan) }
.sa-tool-blurb {
  color: var(--mid);
  font-size: .88rem;
}

/* ── Per-category chips + resource grid ── */
.sa-cat-chips {
  margin-top: 2.25rem;
  margin-bottom: 1.25rem;
}
.sa-cat-grid {
  margin-top: 1rem;
}

@media (max-width: 760px) {
  .sa-tool-list { grid-template-columns: 1fr; column-gap: 0 }
}