/* =============================================================
   CARDS.CSS — Tilt cards used across Research / Projects / Patents /
   Talks / Services / Home previews
   ============================================================= */

.card {
  position: relative;
  padding: clamp(1.5rem, 1.2rem + 1vw, 2.1rem);
  border-radius: var(--r-lg);
  background: var(--surface);
  border: 1px solid var(--border);
  transition: border-color var(--dur-base) var(--ease-out), box-shadow var(--dur-base) var(--ease-out), background var(--dur-base);
}
.card:hover {
  border-color: var(--border-strong);
  box-shadow: var(--shadow-elevated);
  background: var(--surface-hover);
}

.card-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(300px, 1fr)); gap: var(--sp-md); }

/* Generic icon badge — reused by Services, Projects (hackathons), and
   Talks (training) cards. */
.skill-card__icon {
  width: 42px;
  height: 42px;
  border-radius: var(--r-md);
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--surface-strong);
  color: var(--accent-cyan);
  flex-shrink: 0;
}
.card-grid--2 { grid-template-columns: repeat(auto-fit, minmax(340px, 1fr)); }

.card__top {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: var(--sp-sm);
  margin-bottom: var(--sp-sm);
}

.card__title {
  font-size: var(--fs-lg);
  margin-bottom: 0.6rem;
  line-height: var(--lh-snug);
}

.card__meta {
  font-family: var(--font-mono);
  font-size: var(--fs-2xs);
  letter-spacing: 0.04em;
  text-transform: uppercase;
  color: var(--text-faint);
  margin-bottom: 0.75rem;
}

.card__desc {
  color: var(--text-dim);
  font-size: var(--fs-sm);
  line-height: var(--lh-relaxed);
  margin-bottom: 1.1rem;
}

.card__tags {
  display: flex;
  flex-wrap: wrap;
  gap: 0.4rem;
  margin-bottom: 1.1rem;
}

.card__footer {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--sp-sm);
  padding-top: 1rem;
  border-top: 1px solid var(--border);
  flex-wrap: wrap;
}

.card__links { display: flex; gap: 0.6rem; flex-wrap: wrap; }

.card__link {
  display: inline-flex;
  align-items: center;
  gap: 0.35em;
  font-size: var(--fs-xs);
  font-weight: 600;
  color: var(--accent-cyan);
}
.card__link:hover { text-decoration: underline; }

.status-dot {
  display: inline-flex;
  align-items: center;
  gap: 0.5em;
  font-family: var(--font-mono);
  font-size: var(--fs-2xs);
  text-transform: uppercase;
  letter-spacing: 0.06em;
}
.status-dot::before {
  content: "";
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: currentColor;
  box-shadow: 0 0 8px currentColor;
}
.status-dot--published { color: var(--accent-cyan); }
.status-dot--preprint { color: var(--accent-amber); }
.status-dot--pending { color: var(--accent-violet); }
.status-dot--filed, .status-dot--filled { color: var(--accent-magenta); }

.award-strip {
  display: flex;
  align-items: center;
  gap: 0.5em;
  font-size: var(--fs-xs);
  color: var(--accent-amber);
  margin-bottom: 0.85rem;
}

.featured-badge {
  position: absolute;
  top: 1.1rem;
  right: 1.1rem;
  z-index: 2;
}

/* ─── Number index shown on some cards (patents/research) ── */
.card__index {
  font-family: var(--font-mono);
  font-size: var(--fs-xs);
  color: var(--text-faint);
}

/* ─── Filter chip bar ────────────────────────────────────── */
.filter-bar {
  display: flex;
  flex-wrap: wrap;
  gap: 0.55rem;
  margin-bottom: clamp(2rem, 1.6rem + 1.5vw, 3rem);
}
.filter-chip {
  padding: 0.5rem 1rem;
  border-radius: var(--r-full);
  font-size: var(--fs-xs);
  font-weight: 500;
  color: var(--text-dim);
  border: 1px solid var(--border);
  background: var(--surface);
  transition: color var(--dur-fast), border-color var(--dur-fast), background var(--dur-fast);
}
.filter-chip:hover { color: var(--text); border-color: var(--border-strong); }
.filter-chip.is-active {
  color: var(--bg);
  background: var(--gradient-brand);
  border-color: transparent;
}