Create an SVG illustration of an abstract contour-line background similar to topographic map lines. Canvas: - Size: 730x512 px - Background: transparent or black - Main line area starts from the top-left corner and flows toward the center-left and top-middle - Keep the right side and lower-right area mostly empty/negative space Style: - Thin wavy contour lines - Organic flowing curves, like banknote guilloche mixed with topographic map lines - Lines are close together, smooth, irregular, and layered - No filled shapes, only strokes - Stroke color: cyan to blue gradient (#00F5FF, #00B7FF, #006DFF) - Stroke width: 1px to 1.5px - Line opacity varies from 0.25 to 0.9 - Some lines fade out using mask/gradient opacity toward the right and bottom - Add subtle dotted/faded broken segments on the far right/top-right edge - Use SVG paths only, no raster image, no text, no icons Composition: - Dense contour lines in the upper-left - A vertical flowing contour cluster on the left side - Curves create wave-like valleys and ridges - Empty black/transparent space dominates the center-right and bottom-right - Smooth modern fintech/SaaS background accent Output: - Return clean editable SVG code - Use <svg>, <defs>, linearGradient, mask or opacity gradients - Use multiple <path> elements with no fill - Make the SVG lightweight and suitable as website background. Emphasize a cohesive composition, cinematic lighting, high-detail textures, clear depth separation, and polished art direction.

The image shows a black background with blue wavy lines radiating outwards, creating a mesmerizing effect.