diff --git a/README.md b/README.md
index 4d12db6..b01160f 100644
--- a/README.md
+++ b/README.md
@@ -58,11 +58,9 @@ Run the tests locally (against development environment):
 
 ## TODOs
 
-1. Create mod takes null input??
-1. Check status for items not found, should be 404 but getting 5xx
+1. Report 404s better (thread by id and remark by id)
 1. "All new posts flagged" mode (require approval for new posts)
 1. Tests for mod-only user?
-1. Check input validation
 
 ## Crazy future ideas
 
diff --git a/assets/css/elements.css b/assets/css/elements.css
index 9f8de3b..c1a53d9 100644
--- a/assets/css/elements.css
+++ b/assets/css/elements.css
@@ -7,7 +7,7 @@
     --true-gray: #999999;
     --highlight-green: green;
     --highlight-red: red;
-    --transparent: #FFFFFFDD;
+    --transparent: #FFFFFFBB;
 
     box-sizing: border-box;
     font-size: calc(8px + 1vmin);
diff --git a/assets/css/simple.css b/assets/css/simple.css
index 307a02c..7935638 100644
--- a/assets/css/simple.css
+++ b/assets/css/simple.css
@@ -76,6 +76,7 @@
 .form-field {
     display: flex;
     flex-flow: column;
+    gap: 0.25em;
 }
 
 .form-field > textarea {
@@ -97,13 +98,18 @@
     background-color: var(--dark-blue);
 }
 
-.field-with-info {
+.field-with-error {
+    border: dashed var(--highlight-red);
+    padding: 0.5em 0.25em;
+}
+
+.stash-with-info {
     border: dashed var(--highlight-green) 0.5em;
     padding: 1em;
     background-color: var(--transparent);
 }
 
-.field-with-error {
+.stash-with-error {
     border: dashed var(--highlight-red) 0.5em;
     padding: 1em;
     background-color: var(--transparent);
diff --git a/lib/PostText/Controller/Moderator.pm b/lib/PostText/Controller/Moderator.pm
index 6471272..5d152f6 100644
--- a/lib/PostText/Controller/Moderator.pm
+++ b/lib/PostText/Controller/Moderator.pm
@@ -37,8 +37,8 @@ sub login($self) {
     $v = $self->validation if $self->req->method eq 'POST';
 
     if ($v && $v->has_data) {
-        $v->required('email'   );
-        $v->required('password');
+        $v->required('email'   )->size(6,    320);
+        $v->required('password')->size(12, undef);
 
         if ($v->has_error) {
             $self->stash(status => 400)
@@ -154,9 +154,9 @@ sub create($self) {
     $v = $self->validation if $self->req->method eq 'POST';
 
     if ($v && $v->has_data) {
-        $v->required('name'    );
-        $v->required('email'   );
-        $v->required('password');
+        $v->required('name'    )->size(1,     64);
+        $v->required('email'   )->size(6,    320);
+        $v->required('password')->size(12, undef);
 
         if ($v->has_error) {
             $self->stash(status => 400)
@@ -182,8 +182,8 @@ sub admin_reset($self) {
     $v = $self->validation if $self->req->method eq 'POST';
 
     if ($v && $v->has_data) {
-        $v->required('email'   );
-        $v->required('password');
+        $v->required('email'   )->size(6,    320);
+        $v->required('password')->size(12, undef);
 
         if ($v->has_error) {
             $self->stash(status => 400)
@@ -208,7 +208,7 @@ sub mod_reset($self) {
     $v = $self->validation if $self->req->method eq 'POST';
 
     if ($v && $v->has_data) {
-        $v->required('password');
+        $v->required('password')->size(12, undef);
 
         if ($v->has_error) {
             $self->stash(status => 400)
@@ -235,7 +235,7 @@ sub lock_acct($self) {
     $v = $self->validation if $self->req->method eq 'POST';
 
     if ($v && $v->has_data) {
-        $v->required('email');
+        $v->required('email')->size(6, 320);
 
         if ($v->has_error) {
             $self->stash(status => 400)
@@ -257,7 +257,7 @@ sub unlock_acct($self) {
     $v = $self->validation if $self->req->method eq 'POST';
 
     if ($v && $v->has_data) {
-        $v->required('email');
+        $v->required('email')->size(6, 320);
 
         if ($v->has_error) {
             $self->stash(status => 400)
@@ -279,7 +279,7 @@ sub promote($self) {
     $v = $self->validation if $self->req->method eq 'POST';
 
     if ($v && $v->has_data) {
-        $v->required('email');
+        $v->required('email')->size(6, 320);
 
         if ($v->has_error) {
             $self->stash(status => 404)
@@ -301,7 +301,7 @@ sub demote($self) {
     $v = $self->validation if $self->req->method eq 'POST';
 
     if ($v && $v->has_data) {
-        $v->required('email');
+        $v->required('email')->size(6, 320);
 
         if ($v->has_error) {
             $self->stash(status => 404)
diff --git a/t/moderator.t b/t/moderator.t
index 7152f1b..d60d753 100644
--- a/t/moderator.t
+++ b/t/moderator.t
@@ -11,7 +11,7 @@ my %valid_login   = (
 
 my %invalid_login = (
     email    => 'fuck@example.com',
-    password => 'ah fuck'
+    password => 'ah fuck goddamn'
     );
 
 subtest Login => sub {
diff --git a/t/remark.t b/t/remark.t
index fa28d6c..3391e7c 100644
--- a/t/remark.t
+++ b/t/remark.t
@@ -40,7 +40,7 @@ subtest 'Post new remark', sub {
         ->text_like(h2 => qr/Thread #1/);
 
     $t->post_ok('/remark/post/1', form => \%invalid_remark)->status_is(400)
-        ->text_like(p => qr/Invalid text/);
+        ->text_like(p => qr/Must be between/);
 };
 
 subtest 'Flagging remark', sub {
@@ -49,7 +49,7 @@ subtest 'Flagging remark', sub {
         ->text_like(h2 => qr/Remark #1/);
 
     $t->get_ok('/remark/flag/1')->status_is(200)
-        ->element_exists('p[class="field-with-info"]')
+        ->element_exists('p[class="stash-with-info"]')
         ->text_like(p => qr/Remark #1 has been flagged/);
 };
 
diff --git a/t/thread.t b/t/thread.t
index 8a539e3..191abc0 100644
--- a/t/thread.t
+++ b/t/thread.t
@@ -66,10 +66,10 @@ subtest 'Post new thread', sub {
         ->text_like(h2 => qr/New Thread/);
 
     $t->post_ok('/thread/post', form => \%invalid_title)->status_is(400)
-        ->text_like(p => qr/Invalid title/);
+        ->text_like(p => qr/Must be between/);
 
     $t->post_ok('/thread/post', form => \%invalid_post)->status_is(400)
-        ->text_like(p => qr/Invalid text/);
+        ->text_like(p => qr/Must be between/);
 
     $t->post_ok('/thread/post', form => \%valid_params)->status_is(200)
         ->text_like(h2 => qr/Thread #\d+/);
@@ -85,7 +85,7 @@ subtest 'Bumping thread', sub {
         ->text_like(h2 => qr/Thread #1/);
 
     $t->get_ok('/thread/bump/1')->status_is(200)
-        ->element_exists('p[class="field-with-info"]')
+        ->element_exists('p[class="stash-with-info"]')
         ->text_like(p => qr/Thread #1 has been bumped/);
 };
 
@@ -99,7 +99,7 @@ subtest 'Flagging thread', sub {
         ->text_like(h2 => qr/Thread #1/);
 
     $t->get_ok('/thread/flag/1')->status_is(200)
-        ->element_exists('p[class="field-with-info"]')
+        ->element_exists('p[class="stash-with-info"]')
         ->text_like(p => qr/Thread #1 has been flagged/);
 };
 
diff --git a/templates/layouts/default.html.ep b/templates/layouts/default.html.ep
index e70f251..8095c5c 100644
--- a/templates/layouts/default.html.ep
+++ b/templates/layouts/default.html.ep
@@ -44,14 +44,14 @@
   <% } =%>
 </header>
 <% if (flash 'error') { =%>
-<p class="field-with-error" id="error"><%= flash 'error' %></p>
+<p class="stash-with-error" id="error"><%= flash 'error' %></p>
 <% } elsif (stash 'error') { =%>
-<p class="field-with-error" id="error"><%= stash 'error' %></p>
+<p class="stash-with-error" id="error"><%= stash 'error' %></p>
 <% } =%>
 <% if (flash 'info') { =%>
-<p class="field-with-info" id="info"><%= flash 'info' %></p>
+<p class="stash-with-info" id="info"><%= flash 'info' %></p>
 <% } elsif (stash 'info') { =%>
-<p class="field-with-info" id="info"><%= stash 'info' %></p>
+<p class="stash-with-info" id="info"><%= stash 'info' %></p>
 <% } =%>
 <%= content =%>
 <footer class="site-footer">
diff --git a/templates/moderator/admin_reset.html.ep b/templates/moderator/admin_reset.html.ep
index 583084f..95b3dbc 100644
--- a/templates/moderator/admin_reset.html.ep
+++ b/templates/moderator/admin_reset.html.ep
@@ -3,10 +3,18 @@
 <h2 class="page-title"><%= title %></h2>
 <form method="post" class="form-body">
   <div class="form-field">
+    <% if (my $error = validation->error('email')) { =%>
+    <p class="field-with-error">Must be between <%= $error->[2] %>
+      and <%= $error->[3] %> characters.</p>
+    <% } =%>
     <%= label_for email => 'Email' %>
     <%= email_field email => (id => 'email') %>
   </div>
   <div class="form-field">
+    <% if (my $error = validation->error('password')) { =%>
+    <p class="field-with-error">Must be between <%= $error->[2] %>
+      and <%= $error->[3] %> characters.</p>
+    <% } =%>
     <%= label_for password => 'Password' %>
     <%= password_field password => (id => 'password') %>
   </div>
diff --git a/templates/moderator/create.html.ep b/templates/moderator/create.html.ep
index 8c0b7b4..974b21a 100644
--- a/templates/moderator/create.html.ep
+++ b/templates/moderator/create.html.ep
@@ -3,14 +3,26 @@
 <h2 class="page-title"><%= title %></h2>
 <form method="post" class="form-body">
   <div class="form-field">
+    <% if (my $error = validation->error('name')) { =%>
+    <p class="field-with-error">Must be between <%= $error->[2] %>
+      and <%= $error->[3] %> characters.</p>
+    <% } =%>
     <%= label_for name => 'Name' %>
     <%= text_field name => (id => 'name') %>
   </div>
   <div class="form-field">
+    <% if (my $error = validation->error('email')) { =%>
+    <p class="field-with-error">Must be between <%= $error->[2] %>
+      and <%= $error->[3] %> characters.</p>
+    <% } =%>
     <%= label_for email => 'Email' %>
     <%= email_field email => (id => 'email') %>
   </div>
   <div class="form-field">
+    <% if (my $error = validation->error('password')) { =%>
+    <p class="field-with-error">Must be between <%= $error->[2] %>
+      and <%= $error->[3] %> characters.</p>
+    <% } =%>
     <%= label_for password => 'Password' %>
     <%= password_field password => (id => 'password') %>
   </div>
diff --git a/templates/moderator/demote.html.ep b/templates/moderator/demote.html.ep
index acbe9cf..7cf34c3 100644
--- a/templates/moderator/demote.html.ep
+++ b/templates/moderator/demote.html.ep
@@ -3,6 +3,10 @@
 <h2 class="page-title"><%= title %></h2>
 <form method="post" class="form-body">
   <div class="form-field">
+    <% if (my $error = validation->error('email')) { =%>
+    <p class="field-with-error">Must be between <%= $error->[2] %>
+      and <%= $error->[3] %> characters.</p>
+    <% } =%>
     <%= label_for email => 'Email' %>
     <%= email_field email => (id => 'email') %>
   </div>
diff --git a/templates/moderator/lock_acct.html.ep b/templates/moderator/lock_acct.html.ep
index 66d5a80..b55dff1 100644
--- a/templates/moderator/lock_acct.html.ep
+++ b/templates/moderator/lock_acct.html.ep
@@ -3,6 +3,10 @@
 <h2 class="page-title"><%= title %></h2>
 <form method="post" class="form-body">
   <div class="form-field">
+    <% if (my $error = validation->error('email')) { =%>
+    <p class="field-with-error">Must be between <%= $error->[2] %>
+      and <%= $error->[3] %> characters.</p>
+    <% } =%>
     <%= label_for email => 'Email' %>
     <%= email_field email => (id => 'email') %>
   </div>
diff --git a/templates/moderator/login.html.ep b/templates/moderator/login.html.ep
index 7096419..d334a47 100644
--- a/templates/moderator/login.html.ep
+++ b/templates/moderator/login.html.ep
@@ -3,10 +3,18 @@
 <h2 class="page-title"><%= title %></h2>
 <form method="post" class="form-body">
   <div class="form-field">
+    <% if (my $error = validation->error('email')) { =%>
+    <p class="field-with-error">Must be between <%= $error->[2] %>
+      and <%= $error->[3] %> characters.</p>
+    <% } =%>
     <%= label_for email => 'Email' %>
     <%= email_field email => (id => 'email') %>
   </div>
   <div class="form-field">
+    <% if (my $error = validation->error('password')) { =%>
+    <p class="field-with-error">Must be between <%= $error->[2] %>
+      and <%= $error->[3] %> characters.</p>
+    <% } =%>
     <%= label_for password => 'Password' %>
     <%= password_field password => (id => 'password') %>
   </div>
diff --git a/templates/moderator/mod_reset.html.ep b/templates/moderator/mod_reset.html.ep
index 0f85339..298f367 100644
--- a/templates/moderator/mod_reset.html.ep
+++ b/templates/moderator/mod_reset.html.ep
@@ -3,6 +3,10 @@
 <h2 class="page-title"><%= title %></h2>
 <form method="post" class="form-body">
   <div class="form-field">
+    <% if (my $error = validation->error('password')) { =%>
+    <p class="field-with-error">Must be between <%= $error->[2] %>
+      and <%= $error->[3] %> characters.</p>
+    <% } =%>
     <%= label_for password => 'Password' %>
     <%= password_field password => (id => 'password') %>
   </div>
diff --git a/templates/moderator/promote.html.ep b/templates/moderator/promote.html.ep
index b2e0a10..0edcc1c 100644
--- a/templates/moderator/promote.html.ep
+++ b/templates/moderator/promote.html.ep
@@ -3,6 +3,10 @@
 <h2 class="page-title"><%= title %></h2>
 <form method="post" class="form-body">
   <div class="form-field">
+    <% if (my $error = validation->error('email')) { =%>
+    <p class="field-with-error">Must be between <%= $error->[2] %>
+      and <%= $error->[3] %> characters.</p>
+    <% } =%>
     <%= label_for email => 'Email' %>
     <%= email_field email => (id => 'email') %>
   </div>
diff --git a/templates/moderator/unlock_acct.html.ep b/templates/moderator/unlock_acct.html.ep
index 7b7f06a..bb2720c 100644
--- a/templates/moderator/unlock_acct.html.ep
+++ b/templates/moderator/unlock_acct.html.ep
@@ -3,6 +3,10 @@
 <h2 class="page-title"><%= title %></h2>
 <form method="post" class="form-body">
   <div class="form-field">
+    <% if (my $error = validation->error('email')) { =%>
+    <p class="field-with-error">Must be between <%= $error->[2] %>
+      and <%= $error->[3] %> characters.</p>
+    <% } =%>
     <%= label_for email => 'Email' %>
     <%= email_field email => (id => 'email') %>
   </div>
diff --git a/templates/remark/create.html.ep b/templates/remark/create.html.ep
index 970ed09..76f4a89 100644
--- a/templates/remark/create.html.ep
+++ b/templates/remark/create.html.ep
@@ -3,6 +3,10 @@
 <h2 class="page-title"><%= title %></h2>
 <form method="post" class="form-body">
   <div class="form-field">
+    <% if (my $error = validation->error('author')) { =%>
+    <p class="field-with-error">Must be between <%= $error->[2] %>
+      and <%= $error->[3] %> characters.</p>
+    <% } =%>
     <%= label_for author => 'Author' %>
     <%= text_field author => session->{'author'}, (
         id        => 'author',
@@ -10,11 +14,12 @@
         minlength => 1,
         required  => undef
     ) %>
-    <% if (my $error = validation->error('author')) { =%>
-    <p class="field-with-error">Invalid author: 1 to 63 characters please.</p>
-    <% } =%>
   </div>
   <div class="form-field">
+    <% if (my $error = validation->error('body')) { =%>
+    <p class="field-with-error">Must be between <%= $error->[2] %>
+      and <%= $error->[3] %> characters.</p>
+    <% } =%>
     <%= label_for body => 'Text' %>
     <%= text_area body => (
         id        => 'body',
@@ -24,9 +29,6 @@
         rows      => 6,
         autofocus => undef
     ) %>
-    <% if (my $error = validation->error('body')) { =%>
-    <p class="field-with-error">Invalid text: Up to 4,000 characters only.</p>
-    <% } =%>
   </div>
   <button type="submit" class="form-button">Post</button>
 </form>
diff --git a/templates/thread/create.html.ep b/templates/thread/create.html.ep
index 5d748fc..89bd371 100644
--- a/templates/thread/create.html.ep
+++ b/templates/thread/create.html.ep
@@ -3,6 +3,10 @@
 <h2 class="page-title"><%= title %></h2>
 <form method="post" class="form-body">
   <div class="form-field">
+    <% if (my $error = validation->error('author')) { =%>
+    <p class="field-with-error">Must be between <%= $error->[2] %>
+      and <%= $error->[3] %> characters.</p>
+    <% } =%>
     <%= label_for author => 'Author' %>
     <%= text_field author => session->{'author'}, (
         id        => 'author',
@@ -10,11 +14,12 @@
         minlength => 1,
         required  => undef
     ) %>
-    <% if (my $error = validation->error('author')) { =%>
-    <p class="field-with-error">Invalid author: 1 to 63 characters please.</p>
-    <% } =%>
   </div>
   <div class="form-field">
+    <% if (my $error = validation->error('title')) { =%>
+    <p class="field-with-error">Must be between <%= $error->[2] %>
+      and <%= $error->[3] %> characters.</p>
+    <% } =%>
     <%= label_for title => 'Title' %>
     <%= text_field title => (
         id        => 'title',
@@ -23,11 +28,12 @@
         autofocus => undef,
         required  => undef
     ) %>
-    <% if (my $error = validation->error('title')) { =%>
-    <p class="field-with-error">Invalid title: 1 to 127 characters please.</p>
-    <% } =%>
   </div>
   <div class="form-field">
+    <% if (my $error = validation->error('body')) { =%>
+    <p class="field-with-error">Must be between <%= $error->[2] %>
+      and <%= $error->[3] %> characters.</p>
+    <% } =%>
     <%= label_for body => 'Text' %>
     <%= text_area body => (
         id        => 'body',
@@ -36,9 +42,6 @@
         required  => undef,
         rows      => 6
     ) %>
-    <% if (my $error = validation->error('body')) { =%>
-    <p class="field-with-error">Invalid text: Up to 4,000 characters only.</p>
-    <% } =%>
   </div>
   <button type="submit" class="form-button">Post</button>
 </form>