fix(theme): set search box min-width for >=751px

[dnischeta]

Description

This PR closes #250.

Solution

min-width: 176,3px was moved to @media (min-width: 751px) { ... } block (as @nico-bachner suggested in issue).

Result

• 751px
  
• 750px
  
• 720px
  

[dnischeta]

Maybe it is worth to remove padding-left: 8px from @media (min-width: 751px) { ... } rules block. This rule is already set in @media (min-width: 720px) { ... } block.

@media (min-width: 720px) {
  .algolia-search-box {
    padding-left: 8px;
  }
}
@media (min-width: 751px) {
  .algolia-search-box {
    min-width: 176.3px; /* avoid layout shift */
    padding-left: 8px;
  }
  .algolia-search-box .DocSearch-Button-Placeholder {
    padding-left: 8px;
    font-size: 0.9rem;
    font-weight: 500;
  }
}

[nico-bachner]

Nice. Looks good.

To me it seems that

@media (min-width: 751px) {
  .algolia-search-box {
    padding-left: 8px;
  }
}

is indeed superfluous as you say. Not sure if I'm missing anything though.

[dnischeta]

I removed rule repeat with last commit.