layouts/theme/templates/partials/searchform.php
<form method="get" id="searchform" action="<?php echo esc_url( home_url( '/' ) ); ?>">
<label for="s" class="assistive-text"><?php _e( 'Search', '<%= project_id %>' ); ?></label>
<input type="text" class="field" name="s" id="s" placeholder="<?php esc_attr_e( 'Search', '<%= project_id %>' ); ?>" />
<button type="submit" class="submit" name="submit" id="searchsubmit"><?php _e( 'Search', '<%= project_id %>' ); ?></button>
</form>