diff --git a/src/styles.css b/src/styles.css
index 1839b92..95144b0 100644
--- a/src/styles.css
+++ b/src/styles.css
@@ -391,8 +391,8 @@ html, body, #root {
   display: flex;
   align-items: center;
   justify-content: center;
-  width: 22px;
-  height: 22px;
+  width: 24px;
+  height: 24px;
   background: transparent;
   border: 1px solid var(--color-border-subtle);
   border-radius: var(--radius-sm);
@@ -440,14 +440,18 @@ html, body, #root {
   transition: all var(--transition-fast);
   opacity: 0;
   pointer-events: none;
+  visibility: hidden;
 }
 
 .tab-scroll-arrow.visible {
-  opacity: 1;
+  opacity: 0.6;
   pointer-events: auto;
+  visibility: visible;
 }
 
-.tab-scroll-arrow:hover {
+.tab-scroll-arrow.visible:hover,
+.tab-scroll-arrow.visible:focus-visible {
+  opacity: 1;
   color: var(--color-text-primary);
   background-color: var(--color-bg-hover);
 }
@@ -504,8 +508,8 @@ html, body, #root {
 }
 
 .tab-close {
-  width: 18px;
-  height: 18px;
+  width: 24px;
+  height: 24px;
   display: flex;
   align-items: center;
   justify-content: center;
@@ -514,12 +518,13 @@ html, body, #root {
   border-radius: var(--radius-sm);
   color: var(--color-text-tertiary);
   cursor: pointer;
-  opacity: 0;
+  opacity: 0.5;
   flex-shrink: 0;
   transition: all var(--transition-fast);
 }
 
-.tab:hover .tab-close {
+.tab:hover .tab-close,
+.tab-close:focus-visible {
   opacity: 1;
 }
 
@@ -576,13 +581,14 @@ html, body, #root {
   right: 0;
   top: 0;
   bottom: 0;
-  width: 4px;
+  width: 8px;
+  background: rgba(255, 255, 255, 0.06);
   cursor: col-resize;
-  background: transparent;
   transition: background-color var(--transition-fast);
 }
 
-.sidebar-resize-handle:hover {
+.sidebar-resize-handle:hover,
+.sidebar-resize-handle:focus-visible {
   background-color: var(--color-accent);
 }
 
@@ -688,9 +694,11 @@ html, body, #root {
   color: var(--color-text-tertiary);
 }
 
-.search-input:focus {
+.search-input:focus-visible {
   border-color: var(--color-accent);
   background-color: var(--color-bg-base);
+  outline: 2px solid var(--color-accent);
+  outline-offset: -2px;
 }
 
 .search-results {
@@ -1628,6 +1636,19 @@ span.search-highlight.search-highlight-active {
   transition: background-color 0.2s ease, opacity 0.2s ease;
 }
 
+/* Global focus indicator — WCAG 2.4.7, 2.4.13 */
+button:focus-visible,
+a:focus-visible,
+input:focus-visible,
+[tabindex]:focus-visible,
+[role="tab"]:focus-visible,
+[role="menuitem"]:focus-visible,
+[role="separator"]:focus-visible {
+  outline: 2px solid var(--color-accent);
+  outline-offset: 2px;
+  z-index: 1;
+}
+
 /* Reduced motion */
 @media (prefers-reduced-motion: reduce) {
   *,