/* Case Studies hub — filter + card grid */

.cs-filter {
  display: flex; flex-wrap: wrap; gap: 10px; margin-bottom: 44px;
  padding-bottom: 28px; border-bottom: 1px solid var(--line);
}
.cs-filter__btn {
  font-family: var(--sans); font-size: .9rem; font-weight: 600; color: var(--body);
  background: #fff; border: 1px solid var(--line); border-radius: 40px;
  padding: 10px 22px; cursor: pointer; transition: all .2s var(--ease);
}
.cs-filter__btn:hover { border-color: var(--teal); color: var(--teal-deep); }
.cs-filter__btn.is-active { background: var(--ink); border-color: var(--ink); color: #fff; }

.cs-grid {
  display: grid; grid-template-columns: repeat(3, 1fr); gap: var(--gap);
  align-items: start;
}
@media (max-width: 980px) { .cs-grid { grid-template-columns: repeat(2, 1fr); } }
@media (max-width: 680px) { .cs-grid { grid-template-columns: 1fr; } }

.cs-card {
  background: #fff; border: 1px solid var(--line); border-radius: var(--radius-lg);
  padding: 30px 28px; transition: transform .3s var(--ease), box-shadow .3s var(--ease), border-color .3s var(--ease), opacity .3s var(--ease);
}
.cs-card:hover { transform: translateY(-4px); box-shadow: var(--shadow-md); border-color: var(--teal-pale); }
.cs-card.is-hidden { display: none; }

.cs-card__tag {
  display: inline-block; font-size: .68rem; font-weight: 600; letter-spacing: .1em;
  text-transform: uppercase; color: var(--teal-deep); background: var(--teal-wash);
  padding: 5px 11px; border-radius: 3px; margin-bottom: 16px;
}
.cs-card h3 { font-size: 1.22rem; margin-bottom: 18px; line-height: 1.2; }
.cs-card__row { margin-bottom: 14px; }
.cs-card__row:last-of-type { margin-bottom: 0; }
.cs-card__k {
  display: block; font-size: .7rem; font-weight: 600; letter-spacing: .1em;
  text-transform: uppercase; color: var(--muted); margin-bottom: 4px;
}
.cs-card__row p { font-size: .92rem; color: var(--body); line-height: 1.55; margin: 0; }
.cs-card__row strong { color: var(--teal-deep); font-weight: 600; }

/* Feature card (highlighted with a stat) */
.cs-card--feature { border-color: var(--teal); border-width: 1.5px; }
.cs-card__stat {
  margin-top: 20px; padding-top: 18px; border-top: 1px solid var(--line);
}
.cs-card__stat-num {
  font-family: var(--serif); font-size: 1.7rem; font-weight: 600; color: var(--teal);
  letter-spacing: -.01em;
}

.cs-card .code-ref {
  margin-top: 16px; font-family: "SF Mono","Consolas",monospace; font-size: .78rem;
  color: var(--teal-deep); background: var(--teal-wash); display: inline-block;
  padding: 5px 10px; border-radius: 3px;
}

.cs-empty { text-align: center; color: var(--muted); padding: 40px 0; font-size: 1rem; }