style: center trophy + title + meta within playoff banner

Switch the banner to a 3-column grid (1fr auto 1fr) so the main group
sits truly centered regardless of the right-side action cluster width.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

app/static/styles.css

@@ -369,7 +369,8 @@ main {
 /* ── Playoff Banner ─────────────────────────────── */
 
 .playoff-banner {
-    display: flex;
+    display: grid;
+    grid-template-columns: 1fr auto 1fr;
     align-items: center;
     gap: 1rem;
     padding: 0.875rem 1.25rem;
@@ -383,6 +384,22 @@ main {
     display: none;
 }
 
+.banner-main {
+    grid-column: 2;
+    display: flex;
+    align-items: center;
+    gap: 1rem;
+    min-width: 0;
+}
+
+.banner-actions {
+    grid-column: 3;
+    justify-self: end;
+    display: flex;
+    align-items: center;
+    gap: 0.5rem;
+}
+
 .banner-trophy {
     width: 36px;
     height: 44px;
@@ -391,8 +408,8 @@ main {
 }
 
 .banner-text {
-    flex: 1;
     min-width: 0;
+    text-align: center;
 }
 
 .banner-title {
@@ -417,6 +434,7 @@ main {
     margin-top: 0.2rem;
     display: flex;
     flex-wrap: wrap;
+    justify-content: center;
     gap: 0.4rem 0.7rem;
     font-size: 0.75rem;
     color: var(--cup-silver-1);
@@ -478,13 +496,12 @@ main {
 
 @media (max-width: 640px) {
     .playoff-banner {
-        flex-wrap: wrap;
+        grid-template-columns: 1fr;
+        justify-items: center;
         padding: 0.75rem 1rem;
     }
-    .banner-notify {
-        order: 3;
-        margin-left: auto;
-    }
+    .banner-main { grid-column: 1; }
+    .banner-actions { grid-column: 1; justify-self: center; }
 }
 
 /* ── Playoff Game Cards ─────────────────────────── */

app/templates/index.html

@@ -17,6 +17,7 @@
         <span class="header-title">NHL Scoreboard</span>
     </header>
     <section id="playoff-banner" class="playoff-banner hidden" aria-hidden="true">
+        <div class="banner-main">
             <svg class="banner-trophy" viewBox="0 0 32 40" aria-hidden="true">
                 <defs>
                     <linearGradient id="cup-gold" x1="0" x2="1" y1="0" y2="1">
@@ -42,10 +43,13 @@
                     <span class="meta-game7 hidden"></span>
                 </div>
             </div>
+        </div>
+        <div class="banner-actions">
             <a class="banner-bracket-link" href="/bracket">Bracket</a>
             <button class="banner-notify" type="button" title="Notify me on playoff OT" aria-label="Enable OT notifications">
                 <span class="bell-label">OT alerts</span>
             </button>
+        </div>
     </section>
     <main>
         <section id="pinned-section" class="section pinned-section hidden">