mkdocs/docs/assets/css/search-bar.css

/* search bar css */
[data-md-color-scheme="slate"] {
    @media screen and (min-width: 60em) {
      .md-search__overlay {
          background-color: transparent;
      }

      .md-search__form {
          border: 1px solid var(--pg-light-border);
          background-color: var(--md-primary-fg-color) !important;
          box-shadow: rgba(0, 0, 0, 0) 0px 0px 0px 0px, rgba(0, 0, 0, 0) 0px 0px 0px 0px, rgba(0, 0, 0, 0.02) 0px 1px 3px 0px, rgba(0, 0, 0, 0.02) 0px 1px 2px -1px;
          border-radius: 6px;
          height: 1.4rem;
      }

      [data-md-toggle="search"]:checked ~ .md-header .md-search__form {
          border-radius: 6px 6px 0 0;
      }

      [dir="ltr"] .md-search__output {
          top: initial;
          border-radius: 0 0 6px 6px;
      }

      [data-md-toggle="search"]:checked ~ .md-header .md-search__output {
          box-shadow: 0 0 .6rem rgba(0,0,0,.07);
      }

      .md-search__input {
          font-size: .6rem;
      }

      .md-search__options {
          top: .05rem;
      }

      .md-search__icon, .md-search__input::placeholder {
          color: var(--md-default-fg-color--light) !important;
      }

      .md-search__icon svg {
          width: .75rem;
          height: .75rem;
      }
    }
}
[data-md-color-scheme="default"]{
    @media screen and (min-width: 60em) {
      .md-search__overlay {
          background-color: transparent;
      }

      .md-search__form {
          border: 1px solid var(--pg-light-border);
          background-color: var(--md-primary-fg-color) !important;
          box-shadow: rgba(0, 0, 0, 0) 0px 0px 0px 0px, rgba(0, 0, 0, 0) 0px 0px 0px 0px, rgba(0, 0, 0, 0.02) 0px 1px 3px 0px, rgba(0, 0, 0, 0.02) 0px 1px 2px -1px;
          border-radius: 6px;
          height: 1.4rem;
      }

      [data-md-toggle="search"]:checked ~ .md-header .md-search__form {
          border-radius: 6px 6px 0 0;
      }

      [dir="ltr"] .md-search__output {
          top: initial;
          border-radius: 0 0 6px 6px;
      }

      [data-md-toggle="search"]:checked ~ .md-header .md-search__output {
          box-shadow: 0 0 .6rem rgba(0,0,0,.07);
      }

      .md-search__input {
          font-size: .6rem;
      }

      .md-search__options {
          top: .05rem;
      }

      .md-search__icon, .md-search__input::placeholder {
          color: var(--md-default-fg-color--light) !important;
      }

      .md-search__icon svg {
          width: .75rem;
          height: .75rem;
      }
    }
}