Stop the upcoming-lessons row collapsing onto itself

The lesson details and the actions rendered on top of each other. Three
things left the panel fragile, all fixed here.

The rules were bare class selectors while the visually identical
.us-slot row next to them was written as `#us-booking-app .us-slot`.
That inconsistency looks accidental, and it means a theme rule on
div/span/strong outranks the panel's layout and flattens it. Every
booking-page rule is now scoped under #us-booking-app.

The row's two columns were spans carrying display:flex, so the layout
only held while that declaration won. They are divs now — the layout no
longer depends on overriding the inline default.

The row had no flex-wrap and its title column no min-width:0, so a long
offering title could not shrink and shoved the status pill and Cancel
button out of the row. The 640px media query covered only the week
grid, leaving the busier lesson rows with no narrow-viewport handling at
all; they now stack details above actions.

BlockPreview mirrors the markup change so the editor preview matches.

Closes #133

assets/css/frontend.css

@@ -34,47 +34,72 @@
     margin-top: 8px;
 }
 
-.us-my-lessons {
+/*
+ * The upcoming-lessons panel. Every rule here is scoped under #us-booking-app —
+ * the same id-level specificity .us-slot above uses — because these rows sit in
+ * whatever layout the theme provides and carry more content than a calendar
+ * cell. Bare class selectors lost to theme rules on div/span/strong, which
+ * collapsed the flex layout and piled the details on top of the actions.
+ */
+#us-booking-app .us-my-lessons {
     margin-bottom: 24px;
 }
 
-.us-my-lesson {
+#us-booking-app .us-my-lesson {
+    box-sizing: border-box;
+    max-width: 100%;
     border: 1px solid #ddd;
     border-radius: 4px;
     padding: 12px 16px;
     margin-bottom: 8px;
     display: flex;
+    flex-wrap: wrap;
     justify-content: space-between;
     align-items: center;
-    gap: 12px;
+    gap: 8px 12px;
 }
 
-.us-my-lesson-info {
+/*
+ * `min-width: 0` lets the title column shrink below its content width — without
+ * it a long offering title cannot compress and shoves the status pill and
+ * Cancel button out of the row. The flex-basis keeps the details and the
+ * actions on one line while there is room, and wraps them once there is not.
+ */
+#us-booking-app .us-my-lesson-info {
     display: flex;
     flex-direction: column;
     gap: 2px;
+    flex: 1 1 14em;
+    min-width: 0;
 }
 
-.us-my-lesson-title {
+#us-booking-app .us-my-lesson-title,
+#us-booking-app .us-my-lesson-when {
+    overflow-wrap: break-word;
+    word-break: break-word;
+}
+
+#us-booking-app .us-my-lesson-title {
     font-size: 1.05em;
 }
 
-.us-my-lesson-duration {
+#us-booking-app .us-my-lesson-duration {
     font-weight: normal;
     color: #666;
 }
 
-.us-my-lesson-when {
+#us-booking-app .us-my-lesson-when {
     color: #555;
 }
 
-.us-my-lesson-actions {
+#us-booking-app .us-my-lesson-actions {
     display: flex;
-    gap: 12px;
+    flex-wrap: wrap;
+    gap: 8px 12px;
     align-items: center;
 }
 
-.us-show-all-lessons {
+#us-booking-app .us-show-all-lessons {
     background: transparent;
     border: 1px solid #ccc;
     border-radius: 4px;
@@ -82,11 +107,11 @@
     cursor: pointer;
 }
 
-.us-show-all-lessons:hover {
+#us-booking-app .us-show-all-lessons:hover {
     border-color: #888;
 }
 
-.us-cancel-lesson {
+#us-booking-app .us-cancel-lesson {
     background: transparent;
     border: 1px solid #ccc;
     border-radius: 4px;
@@ -95,24 +120,26 @@
     color: #c00;
 }
 
-.us-cancel-lesson:hover {
+#us-booking-app .us-cancel-lesson:hover {
     border-color: #c00;
 }
 
-.us-lesson-status {
+#us-booking-app .us-lesson-status {
+    display: inline-block;
     font-size: 0.85em;
     font-weight: 600;
     padding: 2px 10px;
     border-radius: 10px;
     background: #eee;
+    white-space: nowrap;
 }
 
-.us-lesson-status-confirmed {
+#us-booking-app .us-lesson-status-confirmed {
     background: #e2f5e5;
     color: #1a7d2e;
 }
 
-.us-lesson-status-pending {
+#us-booking-app .us-lesson-status-pending {
     background: #fdf3d7;
     color: #8a6d1a;
 }
@@ -345,6 +372,20 @@
     .us-week-day {
         min-height: 0;
     }
+
+    /*
+     * A lesson row carries a title, a date/time, a status pill and a button —
+     * more than fits one narrow line, so stack the details above the actions
+     * rather than letting them wrap into each other.
+     */
+    #us-booking-app .us-my-lesson {
+        flex-direction: column;
+        align-items: stretch;
+    }
+
+    #us-booking-app .us-my-lesson-info {
+        flex: 0 0 auto;
+    }
 }
 
 /* Shown only in block-editor previews (see BlockPreview). */