header: restore bb-browse-bar styles after DoubleTicker revert

The DoubleTicker commit (a52f8ad, since reverted) had bundled the
.bb-browse-bar / .bb-browse-row / .bb-browse-item CSS rules together
with the ticker CSS. Reverting the ticker removed the Browse bar
styles too, but Header.tsx still uses those classes for the
below-the-leaderboard nav. Re-add just the Browse bar selectors so
that nav renders correctly post-revert.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

src/styles/tailwind.css

@@ -807,4 +807,60 @@ h1, h2, h3 {
 .ProseMirror strong { font-weight: 700; color: #fff; }
 .ProseMirror em { font-style: italic; }
 .ProseMirror u { text-decoration: underline; }
-.ProseMirror s { text-decoration: line-through; }
+.ProseMirror s { text-decoration: line-through; }
+
+/* =====================
+   BROWSE NAV BAR (sits below the 728x90 header banner)
+   ===================== */
+.bb-browse-bar {
+  background: linear-gradient(180deg, #0b0b0b 0%, #0e0e0e 100%);
+  border-top: 1px solid #1a1a1a;
+  border-bottom: 1px solid #1a1a1a;
+  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.4);
+}
+
+.bb-browse-row {
+  display: flex;
+  align-items: stretch;
+  gap: 0;
+  height: 44px;
+}
+
+.bb-browse-item {
+  position: relative;
+  display: inline-flex;
+  align-items: center;
+  padding: 0 16px;
+  font-family: var(--font-body);
+  font-size: 12px;
+  font-weight: 700;
+  letter-spacing: 0.06em;
+  text-transform: uppercase;
+  color: #cccccc;
+  text-decoration: none;
+  border-right: 1px solid #1a1a1a;
+  transition: background 0.15s ease, color 0.15s ease;
+}
+
+.bb-browse-item:first-of-type {
+  border-left: 1px solid #1a1a1a;
+}
+
+.bb-browse-item:hover,
+.bb-browse-item[aria-expanded="true"] {
+  background: #161616;
+  color: var(--color-accent);
+}
+
+.bb-browse-item .bb-browse-caret {
+  display: inline-block;
+  margin-left: 6px;
+  font-size: 8px;
+  opacity: 0.7;
+  transform: translateY(-1px);
+  transition: transform 0.15s ease;
+}
+
+.bb-browse-item[aria-expanded="true"] .bb-browse-caret {
+  transform: rotate(180deg) translateY(1px);
+}