/* ---- Staircase unit ---- */
        .staircase-unit { position: relative; border: 2px solid var(--accent-primary); border-radius: 12px; background: var(--bg-card); padding: 12px; margin-bottom: 14px; box-shadow: 0 4px 15px rgba(0,0,0,0.4); }
        .stair-top { display: flex; justify-content: space-between; align-items: center; margin-bottom: 8px; gap: 8px; flex-wrap: wrap; }
        .stair-top .left, .stair-top .right { display: flex; gap: 8px; align-items: center; flex-wrap: wrap; }
        .stair-relation { font-size: 0.72rem; }
        .stair-canvas-wrap { position: relative; }
        canvas.stair-bg { width: 100%; height: 180px; display: block; border-radius: 8px; background: rgba(0,0,0,0.25); touch-action: none; }
        .stair-readouts { display: flex; align-items: center; gap: 10px; font-size: 0.95rem; color: var(--text-secondary); flex-wrap: wrap; }
        .stair-readouts b { color: var(--accent-yellow); }
        /* ramp controls: a 3-up row of drivers (From / Step size / Steps) + a 2-up timing row */
        .ramp-grid { margin-top: 10px; }
        .ramp-grid .control-group { margin-bottom: 0; display: block; }
        .ramp-grid .control-group > label { margin-bottom: 5px; }
        .ramp-grid .ramp-main { display: grid; grid-template-columns: repeat(4, 1fr); gap: 8px; margin-bottom: 8px; }
        .ramp-grid .ramp-time { display: grid; grid-template-columns: repeat(2, 1fr); gap: 8px; }
        .ramp-grid.count-only { display: grid; grid-template-columns: repeat(3, 1fr); gap: 8px; }
        .repeat-badge { font-size: 0.7rem; color: var(--accent-green); font-weight: 700; }