Tethered Runaway Login Button with Elastic String Physics

Interactive HTML5, SVG & Vanilla JS authentication card with spring-tethered cursor evasion and progressive validation

A playful authentication micro-interaction named Tether. The login button is physically attached to an anchor origin by a dynamic elastic cord. When the cursor approaches with incomplete credentials, the button flees while tilting and stretching against its tether line. As validation requirements are progressively met, evasion damping increases until the button snaps back into the center with an illuminated active state.