WordPress/wp-includes/blocks/search/style.css

.wp-block-search__button{
  margin-left:.625em;
  word-break:normal;
}
.wp-block-search__button.has-icon{
  line-height:0;
}
.wp-block-search__button svg{
  fill:currentColor;
  min-height:1.5em;
  min-width:1.5em;
  vertical-align:text-bottom;
}

:where(.wp-block-search__button){
  border:1px solid #ccc;
  padding:.375em .625em;
}

.wp-block-search__inside-wrapper{
  display:flex;
  flex:auto;
  flex-wrap:nowrap;
  max-width:100%;
}

.wp-block-search__label{
  width:100%;
}

.wp-block-search__input{
  border:1px solid #949494;
  flex-grow:1;
  margin-left:0;
  margin-right:0;
  min-width:3em;
  padding:8px;
  text-decoration:unset !important;
}

.wp-block-search.wp-block-search__button-only .wp-block-search__button{
  margin-left:0;
}

:where(.wp-block-search__button-inside .wp-block-search__inside-wrapper){
  border:1px solid #949494;
  padding:4px;
}
:where(.wp-block-search__button-inside .wp-block-search__inside-wrapper) .wp-block-search__input{
  border:none;
  border-radius:0;
  padding:0 0 0 .25em;
}
:where(.wp-block-search__button-inside .wp-block-search__inside-wrapper) .wp-block-search__input:focus{
  outline:none;
}
:where(.wp-block-search__button-inside .wp-block-search__inside-wrapper) :where(.wp-block-search__button){
  padding:.125em .5em;
}

.wp-block-search.aligncenter .wp-block-search__inside-wrapper{
  margin:auto;
}