修复手机端tab栏吸顶时被header遮挡一半的问题：动态计算header高度

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

中医馆内部管理系统/报告/中医馆内部管理系统_需求分析对比报告_mobile.html

@@ -62,7 +62,7 @@ body {
 
 /* ===== Nav tabs ===== */
 .nav-wrap {
-  position: sticky; top: 52px; z-index: 90;
+  position: sticky; top: var(--header-h, 64px); z-index: 90;
   background: rgba(255,255,255,0.88); backdrop-filter: blur(20px); -webkit-backdrop-filter: blur(20px);
   border-bottom: 0.5px solid rgba(0,0,0,0.06);
 }
@@ -1302,6 +1302,14 @@ function toggleCard(head) {
   card.classList.toggle('open');
 }
 
+// Fix nav-wrap top to match actual header height
+function syncNavTop() {
+  var h = document.querySelector('.header').offsetHeight;
+  document.documentElement.style.setProperty('--header-h', h + 'px');
+}
+syncNavTop();
+window.addEventListener('resize', syncNavTop);
+
 // Expand/collapse all
 function toggleAll(btn) {
   var section = btn.parentElement;