[MD settings] change button padding and placement

chrome/browser/resources/settings/settings_shared_css.html

 <!-- Common styles for Material Design settings. -->
 <dom-module id="settings-shared">
   <template>
     <style>
       :root {
         --checkbox-margin-start: 2px;
         --checkbox-size: 16px;
         --checkbox-spacing: 18px;
         --iron-icon-fill-color: var(--paper-grey-600);
         --iron-icon-height: 20px;
@@ skipping 72 matching lines @@
         /* TODO(dbeam): check with bettes@ on this one, but I'm pretty sure we
          * shouldn't be showing much :hover stuff on Polymer pages. */
         text-decoration: none;
       }
 
       paper-button.primary-button {
         --paper-button: {
           font-weight: 500;
           text-align: start;
         };
-        margin: 0 -0.57em;  /* Offsets default paper-button padding. */
       }
 
       paper-button.secondary-button {
         --paper-button: {
           color: var(--paper-grey-600);
           text-decoration: none;
           font-weight: 500;
         };
       }
 
       paper-button.tertiary-button {
         --paper-button: {
           font-weight: 400;
           text-decoration: none;
         };
       }
 
+      .settings-box paper-button.primary-button,
+      .settings-box paper-button.secondary-button,
+      .settings-box paper-button.secondary-button {
+        margin-left: -12px;
+        margin-right: -12px;
+        padding-left: 12px;
+        padding-right: 12px;
+      }
+
       paper-checkbox {
         --paper-checkbox-checked-color: var(--google-blue-500);
         --paper-checkbox-label-spacing: var(--checkbox-spacing);
         --paper-checkbox-size: var(--checkbox-size);
         --paper-checkbox-unchecked-color: var(--paper-grey-600);
         -webkit-margin-start: var(--checkbox-margin-start);
       }
 
       paper-radio-button {
         @apply(--layout-center);
         --paper-radio-button-checked-color: var(--google-blue-500);
         --paper-radio-button-label-spacing: 18px;
         --paper-radio-button-unchecked-color: var(--paper-grey-600);
         -webkit-margin-start: 2px;
         display: flex;
         min-height: 40px;
       }
 
       paper-radio-group {
         width: 100%;
       }
 
       .text-elide {
         overflow: hidden;
         text-overflow: ellipsis;
         white-space: nowrap;
       }
 
-      .button-row {
-        display: flex;
-        margin-top: 25px;
-      }
-
       .button-strip {
         text-align: end;
       }
 
       .action-button {
         background: var(--google-blue-500);
         color: white;
       }
 
       .action-button[disabled] {
@@ skipping 138 matching lines @@
 
       .favicon-image {
         background-repeat: no-repeat;
         background-size: contain;
         height: 16px;
         width: 16px;
       }
     </style>
   </template>
 </dom-module>