Make sticky sidebar/rail columns independently scrollable

Every sidebar/rail column across the app (feed's left filter panel and
right rail, post detail's left/right rails, profile's sidebar, the
leaderboard's two rails, the dashboard sidebar, and the DeepSearch
citations pane) is `position: sticky` with no max-height or overflow
of its own. When a column's content is taller than the viewport, it
doesn't scroll with the page while pinned - it renders past the
bottom of the screen, unreachable until it "un-sticks" and flies past
during a fast page scroll. Confirmed live: the docs nav sidebar alone
is ~4300px of links against a ~900px viewport.

Each sticky column now gets a max-height matched to its own top
offset, `overflow-y: auto`, `overscroll-behavior: contain`, and a
hidden scrollbar (scrollbar-width/-ms-overflow-style/::-webkit-
scrollbar), the same invisible-scroll recipe already used by the
messages page. Purely additive CSS - no template changes, since every
target already had a distinguishing class.

Fixing the shared `.sidebar-card` component in sidebar.css covers
feed, admin, docs, gists, projects, battles, quizzes, and every
/tools/* page in one place. Also caught and fixed a latent bug along
the way: post.css already neutralized nested `.sidebar-card`s inside
`.post-page-sidebar` (position: static) to stop them independently
double-sticking, but the identical setup on the quiz page
(`.feed-right` wrapping the scoreboard's two `.sidebar-card`s) never
got that override - added the matching `.feed-right .sidebar-card`
rule.

Verified live with Playwright at a squeezed viewport height on feed,
post, profile, leaderboard, docs, and the quiz scoreboard: every
column's scrollTop reaches its true end independently, the center
column never moves, and no scrollbar is visible in any screenshot.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Vnp7vzE4hvsytMo5YjszJm

devplacepy/static/css/deepsearch.css

@@ -545,6 +545,9 @@ dp-deepsearch-chat {
 .ds-chat-log {
     flex: 1;
     overflow-y: auto;
+    overscroll-behavior: contain;
+    scrollbar-width: none;
+    -ms-overflow-style: none;
     padding: var(--space-md);
     display: flex;
     flex-direction: column;
@@ -552,6 +555,11 @@ dp-deepsearch-chat {
     min-height: 240px;
 }
 
+.ds-chat-log::-webkit-scrollbar {
+    width: 0;
+    height: 0;
+}
+
 .ds-chat-msg {
     display: flex;
 }

devplacepy/static/css/feed.css

@@ -221,11 +221,27 @@
 .feed-right {
     position: sticky;
     top: calc(var(--nav-height) + 1rem);
+    max-height: calc(100vh - var(--nav-height) - 2rem);
+    overflow-y: auto;
+    overscroll-behavior: contain;
+    scrollbar-width: none;
+    -ms-overflow-style: none;
     display: flex;
     flex-direction: column;
     gap: 1rem;
 }
 
+.feed-right::-webkit-scrollbar {
+    width: 0;
+    height: 0;
+}
+
+.feed-right .sidebar-card {
+    position: static;
+    max-height: none;
+    overflow: visible;
+}
+
 .daily-topic-card {
     background: var(--bg-card);
     border: 1px solid var(--border);
@@ -493,6 +509,16 @@
 .leaderboard-page > aside {
     position: sticky;
     top: calc(var(--nav-height) + 1rem);
+    max-height: calc(100vh - var(--nav-height) - 2rem);
+    overflow-y: auto;
+    overscroll-behavior: contain;
+    scrollbar-width: none;
+    -ms-overflow-style: none;
+}
+
+.leaderboard-page > aside::-webkit-scrollbar {
+    width: 0;
+    height: 0;
 }
 
 .leaderboard-main {

devplacepy/static/css/landing.css

@@ -272,6 +272,16 @@
     gap: 1rem;
     position: sticky;
     top: 5rem;
+    max-height: calc(100vh - 5rem - 1rem);
+    overflow-y: auto;
+    overscroll-behavior: contain;
+    scrollbar-width: none;
+    -ms-overflow-style: none;
+}
+
+.dashboard-sidebar::-webkit-scrollbar {
+    width: 0;
+    height: 0;
 }
 
 .dashboard-sidebar-card {

devplacepy/static/css/post.css

@@ -13,10 +13,22 @@
     gap: 1rem;
     position: sticky;
     top: calc(var(--nav-height) + 1rem);
+    max-height: calc(100vh - var(--nav-height) - 2rem);
+    overflow-y: auto;
+    overscroll-behavior: contain;
+    scrollbar-width: none;
+    -ms-overflow-style: none;
+}
+
+.post-page-sidebar::-webkit-scrollbar {
+    width: 0;
+    height: 0;
 }
 
 .post-page-sidebar .sidebar-card {
     position: static;
+    max-height: none;
+    overflow: visible;
 }
 
 .post-page {

devplacepy/static/css/profile.css

@@ -10,9 +10,19 @@
 .profile-sidebar {
     position: sticky;
     top: calc(var(--nav-height) + 1rem);
+    max-height: calc(100vh - var(--nav-height) - 2rem);
+    overflow-y: auto;
+    overscroll-behavior: contain;
+    scrollbar-width: none;
+    -ms-overflow-style: none;
     min-width: 0;
 }
 
+.profile-sidebar::-webkit-scrollbar {
+    width: 0;
+    height: 0;
+}
+
 .profile-card {
     background: var(--bg-card);
     border: 1px solid var(--border);

devplacepy/static/css/project_files.css

@@ -53,11 +53,19 @@
     width: 280px;
     flex-shrink: 0;
     overflow: auto;
+    overscroll-behavior: contain;
+    scrollbar-width: none;
+    -ms-overflow-style: none;
     padding: 0.5rem;
     border-right: 1px solid var(--border);
     background: var(--bg-card-hover);
 }
 
+.pf-tree::-webkit-scrollbar {
+    width: 0;
+    height: 0;
+}
+
 .pf-tree-empty {
     padding: 1rem;
     font-size: 0.8125rem;

devplacepy/static/css/sidebar.css

@@ -3,6 +3,11 @@
 .sidebar-card {
     position: sticky;
     top: calc(var(--nav-height) + 1rem);
+    max-height: calc(100vh - var(--nav-height) - 2rem);
+    overflow-y: auto;
+    overscroll-behavior: contain;
+    scrollbar-width: none;
+    -ms-overflow-style: none;
     background: var(--bg-card);
     border: 1px solid var(--border);
     border-radius: var(--radius-lg);
@@ -10,6 +15,11 @@
     padding: 1rem;
 }
 
+.sidebar-card::-webkit-scrollbar {
+    width: 0;
+    height: 0;
+}
+
 .sidebar-card .sidebar-heading {
     font-size: 0.75rem;
     font-weight: 700;

pyproject.toml

@@ -1,6 +1,6 @@
 [project]
 name = "devplacepy"
-version = "1.0.10"
+version = "1.0.11"
 description = "DevPlace - The Developer Social Network"
 requires-python = ">=3.12"
 dependencies = [