diff --git a/static/style.css b/static/style.css
index 9872761..80b625c 100644
--- a/static/style.css
+++ b/static/style.css
@@ -174,6 +174,45 @@ body {
   font-weight: 400;
 }
 
+/* ═══════════════════════════════════════════
+   Sidebar Dark Theme（左侧导航栏专属）
+   ═══════════════════════════════════════════ */
+.sidebar {
+  background: linear-gradient(180deg, #1E293B 0%, #0F172A 100%);
+  border-right: 1px solid #334155;
+}
+.sidebar .user-name {
+  color: #94A3B8;
+}
+.sidebar .user-avatar {
+  background: #4F46E5;
+  color: #FFF;
+}
+.sidebar .btn-logout-icon {
+  color: #64748B;
+}
+.sidebar .btn-logout-icon:hover {
+  background: rgba(248,113,113,0.15);
+  color: #FCA5A5;
+}
+.sidebar .nav-item {
+  color: #94A3B8;
+}
+.sidebar .nav-item:hover {
+  background: rgba(99,102,241,0.08);
+  color: #E2E8F0;
+}
+.sidebar .nav-item .icon-md {
+  color: #6366F1;
+}
+.sidebar .nav-item:hover .icon-md { color: #818CF8; }
+.sidebar .nav-item.active {
+  background: rgba(99,102,241,0.15);
+  color: #FFF;
+  border: 1px solid rgba(99,102,241,0.3);
+}
+.sidebar .nav-item.active .icon-md { color: #818CF8; }
+
 /* ═══════════════════════════════════════════
    Calendar Widget
    ═══════════════════════════════════════════ */