Feat: Frontend app shell

Frontend/src/components/shell/TopBar/TopBar.module.scss

@@ -0,0 +1,85 @@
+.topBar {
+  --topbar-control-size: var(--control-size-md);
+  min-height: 4rem;
+  display: grid;
+  grid-template-columns: minmax(0, 1fr) auto auto;
+  align-items: center;
+  gap: var(--space-3);
+  padding: var(--space-3) var(--space-4) var(--space-3);
+  background: var(--color-surface);
+}
+
+.identity {
+  min-width: 0;
+  display: grid;
+  gap: 0;
+}
+
+.eyebrow {
+  @include text-caption;
+  color: var(--color-text-muted);
+  text-transform: uppercase;
+  letter-spacing: 0.08em;
+}
+
+.title {
+  @include text-title;
+  display: flex;
+  align-items: center;
+  gap: var(--space-2);
+
+  strong {
+    font: inherit;
+    font-weight: var(--font-weight-title);
+  }
+}
+
+.context {
+  color: var(--color-text-muted);
+}
+
+.actions {
+  display: flex;
+  align-items: center;
+  gap: var(--space-1);
+}
+
+.actionButton,
+.themeButton {
+  height: var(--topbar-control-size);
+  display: inline-flex;
+  align-items: center;
+  justify-content: center;
+  @include interactive-frame();
+}
+
+.actionButton {
+  width: var(--topbar-control-size);
+}
+
+.themeButton {
+  width: auto;
+  padding-inline: var(--space-2);
+  gap: var(--space-1);
+  color: var(--color-text);
+}
+
+.actionButton,
+.themeButton {
+  @include interactive-frame-hover();
+}
+
+.themeLabel {
+  @include text-label;
+}
+
+@include respond-down(mobile) {
+  .topBar {
+    grid-template-columns: minmax(0, 1fr) auto;
+    padding: var(--space-2) var(--space-3) var(--space-3);
+  }
+
+  .actions {
+    display: none;
+  }
+}