/* ============================================================
   PROJECTS GRID
   ============================================================ */

#projects {
  padding: var(--section-padding) 0;
  border-top: 1px solid var(--color-border);
}

.projects__header {
  display: flex;
  justify-content: space-between;
  align-items: flex-end;
  margin-bottom: var(--space-12);
  gap: var(--space-8);
  flex-wrap: wrap;
}

.projects__filters {
  display: flex;
  gap: var(--space-2);
  background: var(--color-surface);
  padding: 4px;
  border-radius: var(--radius-md);
  border: 1px solid var(--color-border);
}

.filter-btn {
  background: none;
  border: none;
  color: var(--color-text-secondary);
  padding: var(--space-2) var(--space-4);
  font-family: var(--font-sans);
  font-size: var(--text-sm);
  font-weight: 500;
  cursor: pointer;
  border-radius: var(--radius-sm);
  transition: var(--t-fast);
}

.filter-btn:hover {
  color: var(--color-text-primary);
}

.filter-btn.active {
  background: var(--color-surface-3);
  color: var(--color-accent);
}

/* ── Grid layout ── */
.projects__grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--space-1);
  margin-top: var(--space-12);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-xl);
  overflow: hidden;
}

/* ── Project card ── */
.project-card {
  padding: var(--space-8);
  border: 1px solid transparent;
  background: var(--color-surface);
  position: relative;
  overflow: hidden;
  transition: background var(--t-base), border-color var(--t-base);
  display: flex;
  flex-direction: column;
  gap: var(--space-5);
}

.project-card:hover { background: var(--color-surface-2); }

/* Top-right divider lines between cells */
.project-card:nth-child(odd)  { border-right: 1px solid var(--color-border); }
.project-card:nth-child(1),
.project-card:nth-child(2)    { border-bottom: 1px solid var(--color-border); }

/* ── Large background number ── */
.project-card__num {
  position: absolute;
  top: var(--space-6);
  right: var(--space-6);
  font-family: var(--font-serif);
  font-size: clamp(3rem, 8vw, 6rem);
  color: var(--color-border);
  line-height: 1;
  transition: color var(--t-base);
  pointer-events: none;
  user-select: none;
  z-index: 10;
}

.project-card:hover .project-card__num { color: var(--color-border-2); }

/* ── Thumbnail ── */
.project-card__thumb {
  width: 100%;
  aspect-ratio: 16/9;
  border-radius: var(--radius-md);
  overflow: hidden;
  border: 1px solid var(--color-border);
  background: var(--color-surface-3);
  position: relative;
}

.project-card__thumb img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform var(--t-slow);
}

.project-card:hover .project-card__thumb img {
  transform: scale(1.05);
}

/* placeholder for missing thumb */
.project-card__thumb-placeholder {
  width: 100%;
  height: 100%;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: var(--space-2);
  background: linear-gradient(135deg, var(--color-surface-2) 0%, var(--color-surface-3) 100%);
  color: var(--color-text-muted);
  font-size: var(--text-xs);
  letter-spacing: 0.06em;
}

.project-card__thumb-icon { font-size: 2rem; opacity: 0.4; }

/* ── Meta: title + timeline ── */
.project-card__meta {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  gap: var(--space-4);
}

.project-card__title {
  font-family: var(--font-serif);
  font-size: var(--text-xl);
  color: var(--color-text-primary);
  line-height: 1.2;
  transition: color var(--t-fast);
}

.project-card:hover .project-card__title { color: var(--color-accent); }

.project-card__timeline {
  font-size: var(--text-xs);
  color: var(--color-text-muted);
  letter-spacing: 0.04em;
  flex-shrink: 0;
}

/* ── Problem + solution ── */
.project-card__desc {
  font-size: var(--text-sm);
  color: var(--color-text-secondary);
  line-height: 1.65;
}

/* ── Impact metrics ── */
.project-card__impact {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-3);
}

.impact-item {
  display: flex;
  align-items: center;
  gap: var(--space-1);
  font-size: var(--text-xs);
  color: var(--color-accent-2);
}

.impact-item::before {
  content: '✦';
  font-size: 8px;
}

/* ── Stack badges ── */
.project-card__stack { margin-top: auto; }

/* ── Footer links ── */
.project-card__links {
  display: flex;
  align-items: center;
  justify-content: flex-start;
  padding-top: var(--space-5);
  border-top: 1px solid var(--color-border);
  gap: var(--space-3);
  margin-top: auto;
}

@media (max-width: 768px) {
  .projects__grid { grid-template-columns: 1fr; gap: 0; }
  .project-card { padding: var(--space-5); gap: var(--space-4); }
  .project-card:nth-child(odd)  { border-right: none; border-bottom: 1px solid var(--color-border); }
  .project-card:nth-child(even) { border-bottom: 1px solid var(--color-border); }
  .project-card:last-child { border-bottom: none; }
  .project-card__num { font-size: 3.5rem; top: var(--space-4); right: var(--space-4); }
  .projects__header { flex-direction: column; align-items: flex-start; gap: var(--space-4); }
}