diff --git a/frontend/biochem-library.html b/frontend/biochem-library.html
index 5e239f4..de09ac6 100644
--- a/frontend/biochem-library.html
+++ b/frontend/biochem-library.html
@@ -368,7 +368,7 @@ if (!user) location.href = '/login';
 const nav = document.getElementById('nav-user');
 const ava = document.getElementById('nav-avatar');
 if (nav) nav.textContent = user?.name?.split(' ')[0] || 'Пользователь';
-if (ava) ava.textContent = (user?.name||'LS').split(' ').slice(0,2).map(w=>w[0]?.toUpperCase()||'').join('')||'LS';
+LS.renderNavAvatar(ava, user);
 if (isAdmin)   document.getElementById('btn-admin').style.display = '';
 if (isTeacher) document.getElementById('btn-classes').style.display = '';
 LS.showBoardIfAllowed();
diff --git a/frontend/biochem-properties.html b/frontend/biochem-properties.html
index f5e6bdf..6dc28e1 100644
--- a/frontend/biochem-properties.html
+++ b/frontend/biochem-properties.html
@@ -249,7 +249,7 @@ if (!user) location.href = '/login';
 const nav = document.getElementById('nav-user');
 const ava = document.getElementById('nav-avatar');
 if (nav) nav.textContent = user?.name?.split(' ')[0] || 'Пользователь';
-if (ava) ava.textContent = (user?.name||'LS').split(' ').slice(0,2).map(w=>w[0]?.toUpperCase()||'').join('')||'LS';
+LS.renderNavAvatar(ava, user);
 if (isAdmin) document.getElementById('btn-admin').style.display = '';
 if (isTeacher) document.getElementById('btn-classes').style.display = '';
 LS.showBoardIfAllowed();
diff --git a/frontend/biochem-reactions.html b/frontend/biochem-reactions.html
index 3bd6de8..a57123d 100644
--- a/frontend/biochem-reactions.html
+++ b/frontend/biochem-reactions.html
@@ -369,7 +369,7 @@ if (!user) location.href = '/login';
 const nav = document.getElementById('nav-user');
 const ava = document.getElementById('nav-avatar');
 if (nav) nav.textContent = user?.name?.split(' ')[0] || 'Пользователь';
-if (ava) ava.textContent = (user?.name||'LS').split(' ').slice(0,2).map(w=>w[0]?.toUpperCase()||'').join('')||'LS';
+LS.renderNavAvatar(ava, user);
 if (isAdmin)   document.getElementById('btn-admin').style.display = '';
 if (isTeacher) document.getElementById('btn-classes').style.display = '';
 LS.showBoardIfAllowed();
diff --git a/frontend/biochem.html b/frontend/biochem.html
index 2ddd791..19ee569 100644
--- a/frontend/biochem.html
+++ b/frontend/biochem.html
@@ -532,7 +532,7 @@ if (!user) location.href = '/login';
 const nav = document.getElementById('nav-user');
 const ava = document.getElementById('nav-avatar');
 if (nav) nav.textContent = user?.name?.split(' ')[0] || 'Пользователь';
-if (ava) ava.textContent = (user?.name||'LS').split(' ').slice(0,2).map(w=>w[0]?.toUpperCase()||'').join('')||'LS';
+LS.renderNavAvatar(ava, user);
 if (isAdmin) { document.getElementById('btn-admin').style.display=''; }
 if (isTeacher) { document.getElementById('btn-classes').style.display=''; }
 LS.showBoardIfAllowed();