复古工业风极简主义黑白灰火车发展历史演变插画

minimalist black and white illustration, six different types of trains arranged horizontally from top to bottom: high-speed train, modern passenger train, long formation train, double-section train, vintage steam train, and traditional freight train, each shown in side view, pure white background, clear and intuitive display of transportation diversity and history, no decorative elements, no text, clean and powerful visual effect