add translate

src/styles/main.css

@@ -961,6 +961,125 @@ body {
   color: transparent;
 }
 
+/* Language Selector */
+.lang-selector {
+  position: relative;
+}
+
+.lang-btn {
+  display: flex;
+  align-items: center;
+  justify-content: center;
+  width: 36px;
+  height: 36px;
+  background: #f0f0f0;
+  border: 1px solid #ddd;
+  border-radius: 6px;
+  cursor: pointer;
+  color: #666;
+  font-size: 18px;
+}
+
+.lang-btn:hover {
+  background: #e0e0e0;
+}
+
+.lang-dropdown {
+  display: none;
+  position: absolute;
+  top: 100%;
+  right: 0;
+  margin-top: 4px;
+  background: #fff;
+  border: 1px solid #ddd;
+  border-radius: 8px;
+  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.15);
+  min-width: 140px;
+  z-index: 100;
+  overflow: hidden;
+}
+
+.lang-dropdown.show {
+  display: block;
+}
+
+.lang-option {
+  display: flex;
+  justify-content: space-between;
+  align-items: center;
+  padding: 12px 16px;
+  cursor: pointer;
+  font-size: 14px;
+  transition: background 0.15s;
+}
+
+.lang-option:hover {
+  background: #f5f5f5;
+}
+
+.lang-option.selected {
+  background: linear-gradient(135deg, #f0f7ff 0%, #e8f4ff 100%);
+}
+
+.lang-name {
+  color: #333;
+  font-weight: 500;
+}
+
+.lang-check {
+  width: 18px;
+  height: 18px;
+  border-radius: 50%;
+  border: 2px solid #ccc;
+  display: flex;
+  align-items: center;
+  justify-content: center;
+  font-size: 10px;
+  transition: all 0.2s;
+}
+
+.lang-option.selected .lang-check {
+  background: var(--btn-color);
+  border-color: var(--btn-color);
+  color: #fff;
+}
+
+.lang-option:not(.selected) .lang-check {
+  color: transparent;
+}
+
+/* Content Header (above post list) */
+.content-header {
+  display: flex;
+  justify-content: flex-end;
+  align-items: center;
+  margin-bottom: 8px;
+}
+
+@media (prefers-color-scheme: dark) {
+  .lang-btn {
+    background: #2a2a2a;
+    border-color: #333;
+    color: #888;
+  }
+  .lang-btn:hover {
+    background: #333;
+  }
+  .lang-dropdown {
+    background: #1a1a1a;
+    border-color: #333;
+  }
+  .lang-option:hover {
+    background: #2a2a2a;
+  }
+  .lang-option.selected {
+    background: linear-gradient(135deg, #1a2a3a 0%, #1a3040 100%);
+  }
+  .lang-name {
+    color: #e0e0e0;
+  }
+}
+
 /* AT Browser */
 .server-info {
   padding: 16px 0;