CSS snippet to hide the case toggle:
/* Hide Search's case sensitivity toggle because I never want it and sometimes trigger it by accident, breaking future searches. Related feature request: https://forum.obsidian.md/t/search-move-case-sensitivity-to-the-options-panel/97586
Code modified from that provided by AForAnglerfishRights (@honeydewmelonbordercollie) at https://discord.com/channels/686053708261228577/694233507500916796/1400404824331386971 to always hide it instead of showing it when the search options are open.
*/
.workspace-leaf-content[data-type="search"] .input-right-decorator {
display: none;
}
This essentially removes the case toggle. To allow it to appear when the search options are open, use the snippet in the next comment instead.