.mel-uc-card {
          position: relative; border-radius: 20px; padding: clamp(18px, 2vw, 26px);
          transition: transform .2s ease, box-shadow .2s ease, border-color .2s ease;
        }
        html:not(.dark) .mel-uc-card, html:not(.dark) .mel-uc-chip { --uc-ink: var(--uc-ink-l, #5B4FC7); }
        html.dark .mel-uc-card, html.dark .mel-uc-chip { --uc-ink: var(--uc-ink-d, #A5A0F8); }

        html:not(.dark) .mel-uc-card {
          background: #FFFFFF; border: 1px solid rgba(15,23,42,0.06);
          box-shadow: 0 18px 38px -22px rgba(15,23,42,0.28), 6px 6px 16px rgba(15,23,42,0.07), -6px -6px 16px rgba(255,255,255,0.95);
        }
        html.dark .mel-uc-card {
          background: linear-gradient(180deg, rgba(255,255,255,0.055), rgba(255,255,255,0.015));
          border: 1px solid rgba(255,255,255,0.08);
          box-shadow: 0 24px 52px -24px rgba(0,0,0,0.9), inset 0 1px 0 rgba(255,255,255,0.07);
        }
        .mel-uc-card.is-interactive:hover { transform: translateY(-2px) !important; }
        html:not(.dark) .mel-uc-card.is-interactive:hover {
          box-shadow: 0 24px 44px -22px rgba(15,23,42,0.34), 6px 6px 16px rgba(15,23,42,0.08), -6px -6px 16px rgba(255,255,255,0.95);
        }
        html.dark .mel-uc-card.is-interactive:hover { border-color: rgba(255,255,255,0.14); }
        .mel-uc-card.is-interactive:focus-visible { outline: 2px solid var(--mel-sheet-accent, #7C6FF0); outline-offset: 3px; }

        /* Eyebrow: mono numeral + short rule + label. */
        .mel-uc-eyebrow { display: flex; align-items: center; gap: 10px; margin: 0;
          font: 700 11px/1.4 'JetBrains Mono', ui-monospace, SFMono-Regular, Menlo, monospace;
          letter-spacing: 0.08em; text-transform: uppercase; color: var(--mel-text-tertiary); min-width: 0; }
        .mel-uc-eyebrow .n { color: var(--uc-ink); flex-shrink: 0; }
        .mel-uc-eyebrow .r { width: 20px; height: 1px; background: currentColor; opacity: 0.4; flex-shrink: 0; }
        .mel-uc-eyebrow .l { min-width: 0; overflow-wrap: anywhere; }

        .mel-uc-title { margin: 0; font-family: Poppins, system-ui, sans-serif; font-weight: 700;
          letter-spacing: -0.02em; line-height: 1.22; color: var(--mel-text-primary); text-wrap: balance; }
        .mel-uc-underline { display: block; width: 36px; height: 3px; border-radius: 3px; flex-shrink: 0;
          background: linear-gradient(90deg, var(--mel-sheet-accent, #7C6FF0), var(--mel-sheet-accent2, #22D3EE)); }
        .mel-uc-body { margin: 0; font-family: Poppins, system-ui, sans-serif; line-height: 1.6;
          color: var(--mel-text-secondary); text-wrap: pretty; }

        /* Recessed well (lists, code) inside a card. */
        .mel-uc-well { border-radius: 14px; padding: 12px 14px; }
        html:not(.dark) .mel-uc-well { background: #EEF2F7; box-shadow: inset 3px 3px 7px rgba(15,23,42,0.08), inset -3px -3px 7px rgba(255,255,255,0.9); }
        html.dark .mel-uc-well { background: rgba(4,8,18,0.5); box-shadow: inset 2px 2px 6px rgba(0,0,0,0.55), inset -1px -1px 3px rgba(255,255,255,0.05); }

        /* Small recessed mono chip (stats, persona ids, tool ids). */
        .mel-uc-chip { display: inline-flex; align-items: center; gap: 6px; min-height: 24px; box-sizing: border-box;
          padding: 3px 9px; border-radius: 8px; text-decoration: none; color: var(--uc-ink);
          font: 600 10.5px/1.3 'JetBrains Mono', ui-monospace, SFMono-Regular, monospace; letter-spacing: 0.02em; }
        html:not(.dark) .mel-uc-chip { background: #EEF2F7; box-shadow: inset 1px 1px 3px rgba(15,23,42,0.09), inset -1px -1px 3px rgba(255,255,255,0.95); }
        html.dark .mel-uc-chip { background: rgba(4,8,18,0.5); box-shadow: inset 1px 1px 3px rgba(0,0,0,0.5), inset -1px -1px 2px rgba(255,255,255,0.05); }
        a.mel-uc-chip:hover { text-decoration: underline; text-underline-offset: 2px; }

        /* Status tag (coming soon / stub) — amber, legible per theme. */
        .mel-uc-status { display: inline-flex; align-items: center; align-self: flex-start;
          font: 700 10px/1.3 'JetBrains Mono', ui-monospace, monospace; letter-spacing: 0.12em; text-transform: uppercase;
          padding: 4px 10px; border-radius: 8px; }
        html:not(.dark) .mel-uc-status { color: #B45309; background: #FEF3C7; }
        html.dark .mel-uc-status { color: #FBBF24; background: rgba(245,158,11,0.10); }

        @media (prefers-reduced-motion: reduce) {
          .mel-uc-card { transition: none; }
          .mel-uc-card.is-interactive:hover { transform: none !important; }
        }