Create a large set of minimal stickman icons for an educational psychology explainer video. Style: simple black stickman white background flat vector icon clean lines no shading minimal design consistent icon style Icons needed: stickman thinking stickman scared stickman listening to bad news stickman ignoring good news brain icon danger alert falling stock chart rising stock chart news headline social media notification group panic crowd following fear slow growth plant world progress timeline person overreacting person calm and rational threat detection brain optimism vs pessimism vector icon pack layout simple educational infographic icons