add bootstrap to option select

app/views/admins/_datetime.html.erb

 <div class="row">
   <div class="text col-2">Date:</div>
-  <div class="col-1"><%= f.select :from_year, options_for_select(@years.collect{ |year| year }) %></div>
-  <div class="col-1"><%= f.select :from_month, options_for_select(@months.collect{ |month| month })%></div>
-  <div class="col-1"><%= f.select :from_day, options_for_select(@days.collect{ |day| day })%></div>
+  <div class="form-group mb-2"><%= f.select :from_year, options_for_select(@years.collect{ |year| year }), {}, {class: 'form-control'} %></div>
+  <div class="form-group mb-2"><%= f.select :from_month, options_for_select(@months.collect{ |month| month }), {}, {class: 'form-control'}%></div>
+  <div class="form-group mb-2"><%= f.select :from_day, options_for_select(@days.collect{ |day| day }), {}, {class: 'form-control'}%></div>
   <h4 class="col-1 tilde">~</h4>
-  <div class="col-1"><%= f.select :to_year, options_for_select(@years.collect{ |year| year }), include_blank: 'None'%></div>
-  <div class="col-1"><%= f.select :to_month, options_for_select(@months.collect{ |month| month }), include_blank: 'None'%></div>
-  <div class="col-1"><%= f.select :to_day, options_for_select(@days.collect{ |day| day }), include_blank: 'None'%></div>
+  <div class="form-group mb-2"><%= f.select :to_year, options_for_select(@years.collect{ |year| year }), {prompt: 'None'},{class: 'form-control'}%></div>
+  <div class="form-group mb-2"><%= f.select :to_month, options_for_select(@months.collect{ |month| month }), {prompt: 'None'},{class: 'form-control'}%></div>
+  <div class="form-group mb-2"><%= f.select :to_day, options_for_select(@days.collect{ |day| day }), {prompt: 'None'},{class: 'form-control'}%></div>
 </div>

app/views/admins/_search_condition.html.erb

@@ -6,13 +6,13 @@
     <div class="city-options">
       <div class="row">
         <div class="col-2">City:</div>
-        <div class="col-6"><%= f.select :city_opt, options_for_select(@cities.collect{ |city| [ city.name, city.id] }), include_blank: 'All'%></div>
+        <div class="form-group col-sm"><%= f.select :city_opt, options_for_select(@cities.collect{ |city| [ city.name, city.id] }), {prompt: 'All'}, {class: 'form-control'} %></div>
       </div>
     </div>
     <div class="industry-options">
       <div class="row">
         <div class="col-2">Industry:</div>
-        <div class="col-6"><%= f.select :industry_opt, options_for_select(@industries.collect{ |industry| [ industry.name, industry.id] }), include_blank: 'All' %></div>
+        <div class="form-group col-sm"><%= f.select :industry_opt, options_for_select(@industries.collect{ |industry| [ industry.name, industry.id] }), {prompt: 'All'}, {class: 'form-control'} %></div>
       </div>
     </div>
     <div class="datetime">
@@ -20,10 +20,10 @@
     </div>
     <div class="row">
       <div class="col-3"></div>
-      <div class="search-btn col-4">
+      <div class="search-btn col-3">
         <%= f.submit 'Search', class: 'btn btn-primary' %>
       </div>
-      <div class="download-csv-btn col-4">
+      <div class="download-csv-btn col-sm">
         <% if @apply_job.count > 0 %>
           <%= link_to('Download CSV', download_csv_path(format: :csv), class: 'btn btn-info')%>
         <% else %>