/* PI section – large cards side by side */
    .pi-grid {
      display: grid; grid-template-columns: 1fr 1fr;
      gap: 28px; max-width: 860px; margin: 0 auto;
    }
    .pi-card {
      background: var(--white);
      border: 1.5px solid var(--border);
      border-radius: var(--r-xl);
      overflow: hidden; transition: var(--t);
      position: relative;
    }
    .pi-card::before {
      content: '';
      position: absolute; top: 0; left: 0; right: 0; height: 4px;
      background: linear-gradient(90deg, var(--green-dark), var(--gold));
    }
    .pi-card:hover { transform: translateY(-8px); box-shadow: var(--shadow-lg); border-color: var(--green-mid); }
    .pi-img {
      height: 200px;
      background: linear-gradient(145deg, var(--green-pale) 0%, var(--green-ultra) 100%);
      display: flex; align-items: center; justify-content: center;
      font-size: 5rem;
    }
    .pi-body { padding: 26px; }
    .pi-body h4 { font-size: 1.1rem; margin-bottom: 6px; }
    .pi-role { font-size: 0.78rem; color: var(--green-dark); font-weight: 800; text-transform: uppercase; letter-spacing: 0.8px; margin-bottom: 5px; }
    .pi-affil { font-size: 0.78rem; color: var(--text-muted); margin-bottom: 14px; }

    /* Collaborator compact cards */
    .collab-grid { display: grid; grid-template-columns: repeat(4,1fr); gap: 20px; }
    .collab-card {
      background: var(--white); border: 1.5px solid var(--border);
      border-radius: var(--r-xl); padding: 24px 20px; text-align: center; transition: var(--t);
    }
    .collab-card:hover { border-color: var(--green-mid); box-shadow: var(--shadow-md); transform: translateY(-4px); }
    .collab-card .cc-icon { font-size: 1.8rem; margin-bottom: 12px; }
    .collab-card h4 { font-size: 0.88rem; margin-bottom: 6px; }
    .collab-card p  { font-size: 0.76rem; color: var(--text-muted); }

    @media (max-width: 900px) {
      .pi-grid       { grid-template-columns: 1fr; }
      .collab-grid   { grid-template-columns: repeat(2,1fr); }
    }