Spruce up small inputs with submit buttons

sections/torrents/details.php

     <div class="box box_addartists">
       <div class="head"><strong>Add artist</strong></div>
       <div class="body">
-        <form class="add_form" name="artists" action="torrents.php" method="post">
+        <form class="flex_input_container" name="artists" action="torrents.php" method="post">
           <input type="hidden" name="action" value="add_alias" />
           <input type="hidden" name="auth" value="<?=$LoggedUser['AuthKey']?>" />
           <input type="hidden" name="groupid" value="<?=$GroupID?>" />
-          <input type="text" id="artist" name="artistname[]" size="27"<? Users::has_autocomplete_enabled('other'); ?> />
+          <input type="text" id="artist" name="artistname[]" <? Users::has_autocomplete_enabled('other'); ?> />
           <input type="submit" value="Add" />
         </form>
       </div>
     <div class="box box_addtag">
       <div class="head"><strong>Add tag</strong></div>
       <div class="body">
-        <form class="add_form" name="tags" action="torrents.php" method="post">
+        <form class="flex_input_container" name="tags" action="torrents.php" method="post">
           <input type="hidden" name="action" value="add_tag" />
           <input type="hidden" name="auth" value="<?=$LoggedUser['AuthKey']?>" />
           <input type="hidden" name="groupid" value="<?=$GroupID?>" />
-          <input type="text" name="tagname" id="tagname" size="20"<? Users::has_autocomplete_enabled('other'); ?> />
+          <input type="text" name="tagname" id="tagname" <? Users::has_autocomplete_enabled('other'); ?> />
           <input type="submit" value="Add" />
         </form>
         <br />

sections/user/user.php

 <?
 }
 if (!$OwnProfile && !$LoggedUser['DisablePoints']) { ?>
-    <div class='box point_gift_box'>
-    <div class='head colhead_dark'>Send <?=BONUS_POINTS?></div>
+    <div class="box point_gift_box">
+    <div class="head colhead_dark">Send <?=BONUS_POINTS?></div>
       <div class="pad">
-        <form action='user.php' method='post'>
-          <input type='hidden' name='action' value='points' />
-          <input type='hidden' name='to' value='<?=$UserID?>' />
-          <input type='text' name='amount' placeholder='Amount' /><input type='submit' value='Send' /><br>
-          <textarea name='message' rows='2' placeholder='Message'></textarea><br>
-          <input type='checkbox' name='adjust' /> Adjust for tax?
+        <form action="user.php" method="post">
+          <input type="hidden" name="action" value="points">
+          <input type="hidden" name="to" value="<?=$UserID?>">
+          <div class="flex_input_container">
+            <input type="text" name="amount" placeholder="Amount">
+            <input type="submit" value="Send">
+          </div>
+          <textarea name="message" rows="2" placeholder="Message"></textarea>
+          <label><input type="checkbox" name="adjust"> Adjust for tax?</label>
         </form>
         <p>Note: 10% of your gift is taken as tax.</p>
       </div>

static/styles/global.css

   font-size: 110%;
 }
 
-.sidebar .box .add_form {
+.flex_input_container {
   display: flex;
 }
-.sidebar .box .add_form input[type=text] {
+.flex_input_container > input[type=text]{
   flex-grow: 1;
   box-sizing: border-box;
   width: 100%;

static/styles/oppai/style.css

 .point_gift_box input[type="text"], .point_gift_box textarea {
   width: 100%;
   box-sizing: border-box;
-  margin-bottom: 3px;
 }
 .dead {
   opacity: 0.6;