diff --git a/CHANGELOG.md b/CHANGELOG.md
index 945af09..ab986dd 100755
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -5,6 +5,12 @@ All notable changes to the Peptide Search AI plugin will be documented in this f
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.1.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## [4.6.0] — 2026-04-26
+
+### Changed
+- `assets/css/peptide-search.css`: adopted brand tokens — replaced hardcoded `#2563eb` blue with `var(--teal-500)` family; font → Inter / IBM Plex Mono
+- `assets/css/psa-directory.css`: same token adoption; active tabs/filters → teal; dark mode active states → teal
+
 ## [4.5.1] - 2026-04-23
 
 ### Changed
diff --git a/assets/css/peptide-search.css b/assets/css/peptide-search.css
index e271197..e17452b 100755
--- a/assets/css/peptide-search.css
+++ b/assets/css/peptide-search.css
@@ -6,7 +6,7 @@
 .psa-search-wrap {
     max-width: 720px;
     margin: 2rem auto;
-    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Oxygen, Ubuntu, sans-serif;
+    font-family: "Inter", -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
 }
 
 .psa-search-form {
@@ -16,15 +16,15 @@
 .psa-search-input-wrap {
     display: flex;
     gap: 0;
-    border: 2px solid #2563eb;
+    border: 2px solid var(--teal-500);
     border-radius: 8px;
     overflow: hidden;
     transition: border-color 0.2s;
 }
 
 .psa-search-input-wrap:focus-within {
-    border-color: #1d4ed8;
-    box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.15);
+    border-color: var(--teal-600);
+    box-shadow: 0 0 0 3px rgba(27, 138, 146, 0.15);
 }
 
 .psa-search-input {
@@ -42,13 +42,13 @@
 }
 
 .psa-search-input:focus {
-    outline: 2px solid #2563eb;
+    outline: 2px solid var(--teal-500);
     outline-offset: 2px;
 }
 
 .psa-search-btn {
     padding: 14px 24px;
-    background: #2563eb;
+    background: var(--teal-500);
     color: #fff;
     border: none;
     font-size: 15px;
@@ -59,7 +59,7 @@
 }
 
 .psa-search-btn:hover {
-    background: #1d4ed8;
+    background: var(--teal-600);
 }
 
 .psa-search-btn:focus-visible {
@@ -95,8 +95,8 @@
 }
 
 .psa-result-item:hover {
-    border-color: #2563eb;
-    box-shadow: 0 2px 8px rgba(37, 99, 235, 0.1);
+    border-color: var(--teal-500);
+    box-shadow: 0 2px 8px rgba(27, 138, 146, 0.1);
 }
 
 .psa-result-title {
@@ -146,8 +146,8 @@
 }
 
 .psa-badge-manual {
-    background: #dbeafe;
-    color: #1e40af;
+    background: var(--teal-100);
+    color: var(--teal-700);
 }
 
 /* --- Checking / Loading State --- */
@@ -174,8 +174,8 @@
     display: inline-block;
     width: 36px;
     height: 36px;
-    border: 4px solid #bfdbfe;
-    border-top-color: #2563eb;
+    border: 4px solid var(--teal-100);
+    border-top-color: var(--teal-500);
     border-radius: 50%;
     animation: psa-spin 0.8s linear infinite;
 }
@@ -192,8 +192,8 @@
 .psa-pending-inner {
     text-align: center;
     padding: 40px 32px;
-    background: linear-gradient(135deg, #eff6ff 0%, #f0f9ff 100%);
-    border: 1px solid #bfdbfe;
+    background: linear-gradient(135deg, var(--teal-50) 0%, var(--teal-50) 100%);
+    border: 1px solid var(--teal-100);
     border-radius: 16px;
 }
 
@@ -206,14 +206,14 @@
 .psa-pending-inner h3 {
     margin: 0 0 12px;
     font-size: 21px;
-    color: #1e40af;
+    color: var(--teal-700);
     font-weight: 700;
 }
 
 .psa-pending-inner > p {
     margin: 0 0 28px;
     font-size: 15px;
-    color: #3b82f6;
+    color: var(--teal-400);
     max-width: 500px;
     margin-left: auto;
     margin-right: auto;
@@ -312,7 +312,7 @@
 }
 
 .psa-sequence {
-    font-family: "SF Mono", "Fira Code", "Fira Mono", Menlo, Consolas, monospace;
+    font-family: "IBM Plex Mono", "Fira Code", Menlo, Consolas, monospace;
     font-size: 13px;
     word-break: break-all;
     background: #f1f5f9;
@@ -330,7 +330,7 @@
     color: #1e293b;
     margin: 0 0 12px;
     padding-bottom: 8px;
-    border-bottom: 2px solid #2563eb;
+    border-bottom: 2px solid var(--teal-500);
 }
 
 .psa-section-content {
@@ -360,9 +360,9 @@
 }
 
 .psa-source-badge.psa-badge-manual {
-    background: #eff6ff;
+    background: var(--teal-50);
     border: 1px solid #93c5fd;
-    color: #1e40af;
+    color: var(--teal-700);
 }
 
 /* --- Responsive --- */
diff --git a/assets/css/psa-directory.css b/assets/css/psa-directory.css
index 70e36c4..a183e99 100755
--- a/assets/css/psa-directory.css
+++ b/assets/css/psa-directory.css
@@ -28,7 +28,7 @@
 	max-width: 1200px;
 	margin: 0 auto;
 	padding: 2rem 1rem;
-	font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Oxygen, Ubuntu, sans-serif;
+	font-family: "Inter", -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
 }
 
 /* --- Header --- */
@@ -68,8 +68,8 @@
 }
 
 .psa-dir-search:focus {
-	border-color: #2563eb;
-	box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.15);
+	border-color: var(--teal-500);
+	box-shadow: 0 0 0 3px rgba(27, 138, 146, 0.15);
 }
 
 /* --- Tabs --- */
@@ -97,9 +97,9 @@
 }
 
 .psa-dir-tab--active {
-	background: #2563eb;
+	background: var(--teal-500);
 	color: #fff;
-	border-color: #2563eb;
+	border-color: var(--teal-500);
 }
 
 /* --- Category Filters --- */
@@ -124,14 +124,14 @@
 }
 
 .psa-dir-filter:hover {
-	border-color: #2563eb;
-	color: #2563eb;
+	border-color: var(--teal-500);
+	color: var(--teal-500);
 }
 
 .psa-dir-filter--active {
-	background: #2563eb;
+	background: var(--teal-500);
 	color: #fff;
-	border-color: #2563eb;
+	border-color: var(--teal-500);
 }
 
 /* --- Grid --- */
@@ -153,8 +153,8 @@
 }
 
 .psa-dir-card:hover {
-	border-color: #2563eb;
-	box-shadow: 0 4px 12px rgba(37, 99, 235, 0.08);
+	border-color: var(--teal-500);
+	box-shadow: 0 4px 12px rgba(27, 138, 146, 0.08);
 }
 
 .psa-dir-card__header {
@@ -207,7 +207,7 @@
 	padding: 10px;
 	font-size: 14px;
 	font-weight: 600;
-	background: #2563eb;
+	background: var(--teal-500);
 	color: #fff;
 	border: none;
 	border-radius: 8px;
@@ -217,7 +217,7 @@
 }
 
 .psa-dir-card__btn:hover {
-	background: #1d4ed8;
+	background: var(--teal-600);
 }
 
 /* --- Category Badge Colors --- */
@@ -261,15 +261,15 @@
 	font-size: 15px;
 	font-weight: 600;
 	background: #fff;
-	color: #2563eb;
-	border: 2px solid #2563eb;
+	color: var(--teal-500);
+	border: 2px solid var(--teal-500);
 	border-radius: 8px;
 	cursor: pointer;
 	transition: all 0.2s;
 }
 
 .psa-dir-load-more:hover {
-	background: #2563eb;
+	background: var(--teal-500);
 	color: #fff;
 }
 
@@ -380,7 +380,7 @@
 	padding: 4px 12px;
 	font-size: 12px;
 	font-weight: 600;
-	background: #2563eb;
+	background: var(--teal-500);
 	color: #fff;
 	border: none;
 	border-radius: 4px;
@@ -389,7 +389,7 @@
 }
 
 .psa-dir-modal__copy:hover {
-	background: #1d4ed8;
+	background: var(--teal-600);
 }
 
 /* --- Data Grid --- */
@@ -435,7 +435,7 @@
 	color: #1e293b;
 	margin: 0 0 0.5rem;
 	padding-bottom: 6px;
-	border-bottom: 2px solid #2563eb;
+	border-bottom: 2px solid var(--teal-500);
 }
 
 .psa-dir-modal__section p {
@@ -449,7 +449,7 @@
 .psa-dir-modal__pubchem {
 	display: inline-block;
 	font-size: 13px;
-	color: #2563eb;
+	color: var(--teal-500);
 	text-decoration: none;
 	margin-bottom: 1rem;
 }
@@ -465,7 +465,7 @@
 	font-size: 14px;
 	font-weight: 600;
 	background: #f1f5f9;
-	color: #2563eb;
+	color: var(--teal-500);
 	text-decoration: none;
 	border-radius: 8px;
 	transition: background 0.2s;
@@ -546,7 +546,7 @@
 }
 
 [data-theme="dark"] .psa-dir-tab--active {
-	background: #2563eb;
+	background: var(--teal-500);
 	color: #fff;
 }
 
@@ -557,7 +557,7 @@
 }
 
 [data-theme="dark"] .psa-dir-filter--active {
-	background: #2563eb;
+	background: var(--teal-500);
 	color: #fff;
 }
 
diff --git a/peptide-search-ai.php b/peptide-search-ai.php
index 53f89cc..31cacfc 100755
--- a/peptide-search-ai.php
+++ b/peptide-search-ai.php
@@ -3,7 +3,7 @@
  * Plugin Name: Peptide Search AI
  * Plugin URI:  https://github.com/peptiderepo/peptide-search-ai
  * Description: Searchable peptide database with AI-powered auto-population and browsable directory.
- * Version:     4.5.1
+ * Version:     4.6.0
  * Author:      peptiderepo
  * License:     GPL v2 or later
  * Text Domain: peptide-search-ai