feat(frontend): restyle format picker and add file size to the config card

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

frontend/src/styles/home.css

@@ -59,11 +59,26 @@
   border-radius: 8px;
 }
 
-.file-config-name {
-  font-weight: 500;
+.file-tile-header {
+  display: flex;
+  align-items: center;
+  gap: 0.5rem;
   flex: 1 1 100%;
 }
 
+.file-tile-name {
+  font-weight: 500;
+  flex: 1 1 auto;
+  overflow-wrap: anywhere;
+}
+
+.file-tile-size {
+  font-size: 0.875rem;
+  color: var(--color-foreground);
+  opacity: 0.65;
+  white-space: nowrap;
+}
+
 .file-config-controls {
   display: flex;
   flex-direction: column;
@@ -71,6 +86,52 @@
   flex: 1 1 100%;
 }
 
+.file-config-controls label {
+  display: flex;
+  align-items: center;
+  gap: 0.5rem;
+  font-size: 0.875rem;
+}
+
+.format-select-group {
+  display: flex;
+  align-items: center;
+  gap: 0.5rem;
+}
+
+.format-select {
+  appearance: none;
+  background-color: var(--color-background);
+  color: var(--color-foreground);
+  border: 1px solid var(--color-border);
+  border-radius: 8px;
+  padding: 0.5rem 2rem 0.5rem 0.75rem;
+  font-weight: 500;
+  min-height: 44px;
+  background-image:
+    linear-gradient(45deg, transparent 50%, var(--color-foreground) 50%),
+    linear-gradient(135deg, var(--color-foreground) 50%, transparent 50%);
+  background-position:
+    calc(100% - 17px) calc(1.15em),
+    calc(100% - 12px) calc(1.15em);
+  background-size: 5px 5px, 5px 5px;
+  background-repeat: no-repeat;
+}
+
+.format-select:focus-visible {
+  border-color: var(--color-ring);
+}
+
+.format-badge {
+  background: var(--color-muted);
+  color: var(--color-primary);
+  border-radius: 999px;
+  padding: 0.25rem 0.6rem;
+  font-size: 0.75rem;
+  font-weight: 700;
+  letter-spacing: 0.03em;
+}
+
 .convert-button {
   background: var(--color-accent);
   color: var(--color-on-primary);