css - How to make div tags expand to content when one drops below the other -

I am currently creating a CSS layout and I have side divs on one side in the main content when the page is below the other A droplet is resized when this happens, so I want to take the top div to the width of the parent div

#MainWrapper #Content {float: left; Background color: # E4E4E4; Width: 100%; Max-width: 1180px; Clear: left; Font-family: helpless; } #WelcomeTax {max-width: 500px; Minimum width: 100%; Background color: # 399; Display: inline-block; } # Slideshow {width: 100px; Background color: # C96; Minimum width: 200px; Display: inline-block; }

With your previous comment, I think you want to see @media queries Are there.

You can ask to change the specific properties when the width of the window decreases by your specified width.

  @ Media (max-width: 600px) {#Welcometext {typical properties for a screen size under 600px; }}