style: adopt mewlody workspace shell

src/styles.css

@@ -97,7 +97,7 @@ button:hover:not(:disabled) {
   height: 42px;
   display: flex;
   align-items: center;
-  gap: 28px;
+  gap: 16px;
   padding: 0 16px;
   border-bottom: 1px solid var(--ui-divider);
   background: var(--ed-bg);
@@ -115,36 +115,6 @@ button:hover:not(:disabled) {
   color: var(--ed-accent);
   font-size: 16px;
 }
-.top-nav {
-  display: flex;
-  align-self: stretch;
-  gap: 24px;
-}
-.nav-item {
-  position: relative;
-  padding: 0;
-  border: 0;
-  border-radius: 0;
-  color: var(--ed-dim);
-  background: transparent;
-  font: 10px var(--font-data);
-  letter-spacing: 0.16em;
-  text-transform: uppercase;
-}
-.nav-item:hover,
-.nav-item.active {
-  color: var(--ed-fg);
-  background: transparent;
-}
-.nav-item.active::after {
-  position: absolute;
-  right: 0;
-  bottom: 0;
-  left: 0;
-  height: 2px;
-  background: var(--ed-accent);
-  content: '';
-}
 .app-actions {
   display: flex;
   align-items: center;
@@ -180,6 +150,29 @@ button:hover:not(:disabled) {
   border-right: 1px solid var(--ui-divider);
   background: color-mix(in srgb, var(--ed-panel) 80%, var(--ed-bg));
 }
+.side-nav {
+  display: flex;
+  flex-direction: column;
+  padding: 8px 0;
+  border-bottom: 1px solid var(--ui-divider);
+}
+.side-nav-item {
+  width: 100%;
+  padding: 7px 10px;
+  border: 0;
+  border-left: 2px solid transparent;
+  border-radius: 0;
+  color: var(--ed-dim);
+  background: transparent;
+  font: 11px var(--font-body);
+  text-align: left;
+}
+.side-nav-item:hover,
+.side-nav-item.active {
+  border-left-color: var(--ed-accent);
+  color: var(--ed-fg);
+  background: color-mix(in srgb, var(--ed-accent) 6%, var(--ed-panel));
+}
 .panel-header {
   display: flex;
   align-items: center;