fix: let the dashboard use the full pane width

Obsidian caps note content at --file-line-width (~700px) with readable
line length on, which squeezed the two-pane grid into a column. Widen
only the sizer that contains a dashboard via :has(), so every other note
keeps its readable width, and cap the dashboard itself at 1600px.

Also swap the collapse breakpoint to a container query. A media query
measures the window, so a wide window with the dashboard in a narrow
split pane kept two cramped columns; the container query responds to the
pane. The media query stays as a floor for a narrow window.

.obsidian/plugins/webinar-dash/styles.css

@@ -28,6 +28,13 @@
   display: flex;
   flex-direction: column;
   gap: 16px;
+  /* Past roughly this width the two panes stop reading as a pair and table
+     rows get hard to track across. Cap the whole dashboard, not just the
+     grid, so the toolbar stays flush with the panes below it. */
+  max-width: 1600px;
+  /* Makes this element the reference for the @container query further down,
+     so the grid collapses on the pane's width rather than the window's. */
+  container-type: inline-size;
 }
 
 .theme-dark .webinar-dash {
@@ -55,6 +62,28 @@
   --wd-danger: #ff5c50;
 }
 
+/* ------------------------------------------------------------------
+   Escape Obsidian's readable-line-length cap.
+
+   With "Readable line length" on (the default), Obsidian caps note
+   content at --file-line-width, roughly 700px. That is right for prose
+   and wrong for a two-pane dashboard, which gets squeezed into a column.
+
+   :has() scopes this to the sizer that actually contains a dashboard, so
+   every other note in the vault keeps its readable width. Both selectors
+   are needed: reading view sizes on .markdown-preview-sizer, live preview
+   on .cm-sizer.
+
+   If you would rather not rely on this, the alternatives are Settings ->
+   Editor -> Readable line length (off, but that widens every note), or
+   adding `cssclasses: wide-dash` to the note's frontmatter and swapping
+   the :has() selectors below for `.wide-dash .markdown-preview-sizer`.
+   ------------------------------------------------------------------ */
+.markdown-preview-sizer:has(.webinar-dash),
+.markdown-source-view.mod-cm6 .cm-sizer:has(.webinar-dash) {
+  max-width: none;
+}
+
 .wd-grid {
   display: grid;
   grid-template-columns: minmax(0, 38fr) minmax(0, 62fr);
@@ -83,6 +112,15 @@
   border-color: var(--wd-border-strong);
 }
 
+/* Collapse to one column on the width that actually matters — the pane's,
+   not the window's. A media query measures the window, so a wide window
+   with the dashboard in a narrow split pane would keep two cramped
+   columns. The container query below responds to the pane itself; the
+   media query stays as a floor for a genuinely narrow window. */
+@container (max-width: 820px) {
+  .wd-grid { grid-template-columns: minmax(0, 1fr); }
+}
+
 @media (max-width: 820px) {
   .wd-grid { grid-template-columns: minmax(0, 1fr); }
 }