diff --git a/src/App.svelte b/src/App.svelte
index 52f9b87..c5a91cf 100644
--- a/src/App.svelte
+++ b/src/App.svelte
@@ -188,9 +188,23 @@
       <div
         class="resize-handle"
         class:active={isResizing}
-        role="separator"
+        role="slider"
         aria-orientation="horizontal"
+        aria-label="Resize timeline and clip list"
+        aria-valuenow={timelineHeight}
+        aria-valuemin={40}
+        aria-valuemax={500}
+        tabindex="0"
         onmousedown={handleResizeStart}
+        onkeydown={(e) => {
+          if (e.key === 'ArrowDown') {
+            e.preventDefault();
+            timelineHeight = Math.min(500, timelineHeight + 10);
+          } else if (e.key === 'ArrowUp') {
+            e.preventDefault();
+            timelineHeight = Math.max(40, timelineHeight - 10);
+          }
+        }}
       ></div>
       <div class="cliplist-pane">
         <ClipList onExport={() => (showExportDialog = true)} />
diff --git a/src/lib/components/AboutDialog.svelte b/src/lib/components/AboutDialog.svelte
index 870f158..d694ce4 100644
--- a/src/lib/components/AboutDialog.svelte
+++ b/src/lib/components/AboutDialog.svelte
@@ -12,8 +12,25 @@
   });
 </script>
 
-<div class="overlay" role="presentation" onclick={onClose}>
-  <div class="dialog" role="dialog" onclick={(e) => e.stopPropagation()}>
+<div
+  class="overlay"
+  role="presentation"
+  tabindex="-1"
+  onclick={onClose}
+  onkeydown={(e) => {
+    if (e.key === 'Escape' || e.key === 'Enter' || e.key === ' ') {
+      if (e.key !== 'Escape') e.preventDefault();
+      onClose();
+    }
+  }}
+>
+  <div
+    class="dialog"
+    role="dialog"
+    tabindex="-1"
+    onclick={(e) => e.stopPropagation()}
+    onkeydown={(e) => e.stopPropagation()}
+  >
     <img class="app-icon" src="/favicon.svg" alt="GUI Video Clipper icon" />
     <h2>GUI Video Clipper</h2>
     {#if version}
diff --git a/src/lib/components/CaptionSettingsPanel.svelte b/src/lib/components/CaptionSettingsPanel.svelte
index 0db9149..75d1e67 100644
--- a/src/lib/components/CaptionSettingsPanel.svelte
+++ b/src/lib/components/CaptionSettingsPanel.svelte
@@ -45,8 +45,9 @@
   <div class="scroll-area">
     <!-- Font Family -->
     <div class="control">
-      <label>Font</label>
+      <label for="caption-font">Font</label>
       <select
+        id="caption-font"
         value={settings.fontFamily}
         onchange={(e) => update({ fontFamily: (e.target as HTMLSelectElement).value })}
       >
@@ -61,19 +62,20 @@
       <label>
         Font Size
         <span class="value">{settings.fontSize}px</span>
+        <input
+          type="range" min="12" max="36" step="1"
+          value={settings.fontSize}
+          oninput={(e) => update({ fontSize: parseInt((e.target as HTMLInputElement).value, 10) })}
+        />
       </label>
-      <input
-        type="range" min="12" max="36" step="1"
-        value={settings.fontSize}
-        oninput={(e) => update({ fontSize: parseInt((e.target as HTMLInputElement).value, 10) })}
-      />
     </div>
 
     <!-- Text Color + Bold -->
     <div class="control row">
-      <label>Text Color</label>
+      <label for="caption-text-color">Text Color</label>
       <div class="row-controls">
         <input
+          id="caption-text-color"
           type="color" value={settings.textColor}
           oninput={(e) => update({ textColor: (e.target as HTMLInputElement).value })}
         />
@@ -87,10 +89,10 @@
 
     <!-- Dimmed Text Color -->
     <div class="control">
-      <label>Dimmed Text</label>
+      <label for="caption-dimmed-auto">Dimmed Text</label>
       <div class="radio-row">
         <label>
-          <input type="radio" name="dimmed-mode" value="auto"
+          <input id="caption-dimmed-auto" type="radio" name="dimmed-mode" value="auto"
             checked={settings.dimmedColorMode === 'auto'}
             onchange={() => update({ dimmedColorMode: 'auto' })} />
           Auto
@@ -108,18 +110,19 @@
         <label>
           Dim Opacity
           <span class="value">{Math.round(settings.dimmedOpacity * 100)}%</span>
+          <input
+            type="range" min="10" max="90" step="5"
+            value={Math.round(settings.dimmedOpacity * 100)}
+            oninput={(e) => update({ dimmedOpacity: parseInt((e.target as HTMLInputElement).value, 10) / 100 })}
+          />
         </label>
-        <input
-          type="range" min="10" max="90" step="5"
-          value={Math.round(settings.dimmedOpacity * 100)}
-          oninput={(e) => update({ dimmedOpacity: parseInt((e.target as HTMLInputElement).value, 10) / 100 })}
-        />
       </div>
     {:else}
       <div class="control row">
-        <label>Dimmed Color</label>
+        <label for="caption-dimmed-color">Dimmed Color</label>
         <div class="row-controls">
           <input
+            id="caption-dimmed-color"
             type="color" value={settings.dimmedColor}
             oninput={(e) => update({ dimmedColor: (e.target as HTMLInputElement).value })}
           />
@@ -165,12 +168,12 @@
         <label>
           BG Opacity
           <span class="value">{Math.round(settings.backgroundOpacity * 100)}%</span>
+          <input
+            type="range" min="0" max="100" step="5"
+            value={Math.round(settings.backgroundOpacity * 100)}
+            oninput={(e) => update({ backgroundOpacity: parseInt((e.target as HTMLInputElement).value, 10) / 100 })}
+          />
         </label>
-        <input
-          type="range" min="0" max="100" step="5"
-          value={Math.round(settings.backgroundOpacity * 100)}
-          oninput={(e) => update({ backgroundOpacity: parseInt((e.target as HTMLInputElement).value, 10) / 100 })}
-        />
       </div>
     {/if}
 
@@ -195,21 +198,21 @@
         <label>
           Shadow Depth
           <span class="value">{settings.shadowDepth}px</span>
+          <input
+            type="range" min="1" max="5" step="1"
+            value={settings.shadowDepth}
+            oninput={(e) => update({ shadowDepth: parseInt((e.target as HTMLInputElement).value, 10) })}
+          />
         </label>
-        <input
-          type="range" min="1" max="5" step="1"
-          value={settings.shadowDepth}
-          oninput={(e) => update({ shadowDepth: parseInt((e.target as HTMLInputElement).value, 10) })}
-        />
       </div>
     {/if}
 
     <!-- Position -->
     <div class="control">
-      <label>Position</label>
+      <label for="caption-pos-bottom">Position</label>
       <div class="radio-row">
         <label>
-          <input type="radio" name="caption-position" value="bottom"
+          <input id="caption-pos-bottom" type="radio" name="caption-position" value="bottom"
             checked={settings.position === 'bottom'}
             onchange={() => update({ position: 'bottom' })} />
           Bottom
diff --git a/src/lib/components/ClipList.svelte b/src/lib/components/ClipList.svelte
index 1b35873..9fc0bfe 100644
--- a/src/lib/components/ClipList.svelte
+++ b/src/lib/components/ClipList.svelte
@@ -43,7 +43,17 @@
   }
 </script>
 
-<div class="clip-list" role="listbox" onclick={handleContainerClick}>
+<div
+  class="clip-list"
+  role="listbox"
+  tabindex="0"
+  onclick={handleContainerClick}
+  onkeydown={(e) => {
+    if (e.key === 'Escape') {
+      selectClip(null);
+    }
+  }}
+>
   {#if clips.length === 0}
     <div class="empty">No clips yet — press I to mark in-point, O to mark out-point</div>
   {:else}
diff --git a/src/lib/components/ExportDialog.svelte b/src/lib/components/ExportDialog.svelte
index 5166551..c6b38c7 100644
--- a/src/lib/components/ExportDialog.svelte
+++ b/src/lib/components/ExportDialog.svelte
@@ -136,8 +136,25 @@
   }
 </script>
 
-<div class="overlay" role="presentation" onclick={onClose}>
-  <div class="dialog" role="dialog" onclick={(e) => e.stopPropagation()}>
+<div
+  class="overlay"
+  role="presentation"
+  tabindex="-1"
+  onclick={onClose}
+  onkeydown={(e) => {
+    if (e.key === 'Escape' || e.key === 'Enter' || e.key === ' ') {
+      if (e.key !== 'Escape') e.preventDefault();
+      onClose();
+    }
+  }}
+>
+  <div
+    class="dialog"
+    role="dialog"
+    tabindex="-1"
+    onclick={(e) => e.stopPropagation()}
+    onkeydown={(e) => e.stopPropagation()}
+  >
     <h2>Export Clips</h2>
 
     {#if !isExportReady}
diff --git a/src/lib/components/PreferencesPanel.svelte b/src/lib/components/PreferencesPanel.svelte
index 1f3901b..a088463 100644
--- a/src/lib/components/PreferencesPanel.svelte
+++ b/src/lib/components/PreferencesPanel.svelte
@@ -57,8 +57,25 @@
   }
 </script>
 
-<div class="overlay" role="presentation" onclick={onClose}>
-  <div class="panel" role="dialog" onclick={(e) => e.stopPropagation()}>
+<div
+  class="overlay"
+  role="presentation"
+  tabindex="-1"
+  onclick={onClose}
+  onkeydown={(e) => {
+    if (e.key === 'Escape' || e.key === 'Enter' || e.key === ' ') {
+      if (e.key !== 'Escape') e.preventDefault();
+      onClose();
+    }
+  }}
+>
+  <div
+    class="panel"
+    role="dialog"
+    tabindex="-1"
+    onclick={(e) => e.stopPropagation()}
+    onkeydown={(e) => e.stopPropagation()}
+  >
     <h2>Preferences</h2>
 
     <section>
diff --git a/src/lib/components/VideoPlayer.svelte b/src/lib/components/VideoPlayer.svelte
index 36842e3..f42a877 100644
--- a/src/lib/components/VideoPlayer.svelte
+++ b/src/lib/components/VideoPlayer.svelte
@@ -194,7 +194,9 @@
       onloadeddata={handleLoadedData}
       preload="metadata"
       playsinline
-    ></video>
+    >
+      <track kind="captions" />
+    </video>
     {#if activeCues.length > 0}
       <div class="caption-overlay" style={captionPosition}>
         {#each activeCues as cue}