.header_main{
  align-items:center;
  display:grid;
  gap: var(--space-3);
  grid-template-areas: "a b";
  grid-template-columns: 1fr min-content;
  padding: var(--space-5) 0}
.header_main > .small{ grid-area: a}
.header_main > .flexd{ 
  grid-area: b; 
  width: 360px}
.header_main input[type="search"]{ 
  flex: 1 1 auto; 
  min-width: 0}
.header_main button{ flex: 0 0 auto}
@media (max-width:700px){
  .header_main{
    grid-template-columns: 1fr;
    grid-template-areas: "a" "b"}
  .header_main .flexd{width:100%}
}