more cleanup

src/registrar/assets/src/sass/_theme/_containers.scss

@@ -22,5 +22,5 @@
 // regular grid-container within a widescreen (see instances
 // where is_widescreen_centered is used in the html).
 .max-width--grid-container {
-  max-width: 64rem;
+  max-width: 960px;
 }

src/registrar/templates/domain_base.html

@@ -19,8 +19,8 @@
       {% endif %}
     </div>
 
-    <div class="tablet:grid-col-9 maxw-fit-content">
-      <main id="main-content">
+    <div class="tablet:grid-col-9">
+      <main id="main-content" class="grid-container">
       {% if not domain.domain_info %}
         <div class="usa-alert usa-alert--error margin-bottom-2">
           <div class="usa-alert__body">

src/registrar/templates/domain_detail.html

@@ -20,7 +20,7 @@
   {% endblock breadcrumb %}
 
   {{ block.super }}
-  <div class="margin-top-4 tablet:grid-col-10 maxw-fit-content">
+  <div class="margin-top-4 tablet:grid-col-10">
     <h2 class="text-bold text-primary-dark domain-name-wrap">{{ domain.name }}</h2>
     <div
         class="usa-summary-box dotgov-status-box padding-bottom-0 margin-top-3 padding-left-2{% if not domain.is_expired %}{% if domain.state == domain.State.UNKNOWN or domain.state == domain.State.DNS_NEEDED %} dotgov-status-box--action-need{% endif %}{% endif %}"

src/registrar/templates/domain_request_form.html

@@ -8,7 +8,7 @@
     <div class="tablet:grid-col-3">
       {% include 'domain_request_sidebar.html' %}
     </div>
-    <div class="tablet:grid-col-9 maxw-fit-content">
+    <div class="tablet:grid-col-9">
       <main id="main-content" class="register-form-step">
         <input type="hidden" class="display-none" id="wizard-domain-request-id" value="{{domain_request_id}}"/>
         {% if steps.current == steps.first %}