/* -------- 7. Виньетка (драматичное затемнение по краям) -------- */
        .section.dark {
            background: #141414;
            background-image: url('../txtr2/black-marble.jpg');
            background-size: cover;
            background-blend-mode: overlay;
            position: relative;
            isolation: isolate;
        }
        .section.dark::before {
            content: '';
            position: absolute;
            inset: 0;
            z-index: -1;
            pointer-events: none;
            background:
                radial-gradient(ellipse at 50% 50%, transparent 0%, rgba(0, 0, 0, 0.6) 60%, #0a0a0a 100%);
            mix-blend-mode: multiply;
        }
        .section.dark::after {
            content: '';
            position: absolute;
            inset: 0;
            z-index: 1;
            pointer-events: none;
            background: 
                radial-gradient(ellipse at 50% 40%, rgba(255, 255, 255, 0.05) 0%, transparent 50%);
            mix-blend-mode: soft-light;
        }
        .section.dark .wrap { z-index: 2; position: relative; }