CSS Selectors - change width if last image id is X -

i try several hours figure out how change width of class if there image id before element.

currently code looks that

<blockquote> <img id="bp_avatar" src="..."> <p>text</p> </blockquote  

the problem image been dynamicly inserted, in cases there in other wont. tried wrap image inside text, fit blockquote p needs width of 90%.

so here issue, should 90% if it's there , 100% if not there. use css instead of jquery, found on w3 documents level 4 selectors , tried use them, goal apply style if #bp_avatar there.

so tried ways

#bp_avatar ~ #bluepostq blockquote p  { width: 90%!important; }   #bluepostq blockquote p! > #bp_avatar{ width: 90%!important;         } 

none of them worked yust nothing happens, think missunderstood , hope tell me have done wrong.

using ~ correct, need use bit differently:

p {   width: 100%; } #bp_avatar ~ p {   width: 90%; } 

this make p 100% width if preceded #bp_avatar 90%.

if attempting limit within element (maybe #bluepostq isn't in sample html) go first in selector:

#bluepostq #bp_avatar ~ p { 

additionally, if know p next element after #bp_avatar, can use adjacent sibling selector:

#bp_avatar + p { 

blockquote{    border: 1px solid red;  }  p{    border: 1px solid blue;    display: inline-block;    width: 100%;  }  img{    border: 1px solid green;  }    #bp_avatar ~ p {    width: 90%;  }

<blockquote>    <img id="bp_avatar" src="...">    <p>text</p>  </blockquote>  <blockquote>    <p>text</p>  </blockquote>

https://jsfiddle.net/ezlaaoco/