diff --git a/release/UNIVERSAL_SpineViewer/viewer/spine.css b/release/UNIVERSAL_SpineViewer/viewer/spine.css
index bb4c8bc..8afc975 100644
--- a/release/UNIVERSAL_SpineViewer/viewer/spine.css
+++ b/release/UNIVERSAL_SpineViewer/viewer/spine.css
@@ -77,6 +77,21 @@
 		button.active { background: var(--accent); color: #fff; border-color: var(--accent); }
 		button.primary { background: var(--accent); color: #fff; border-color: var(--accent); }
 		button:disabled { cursor: default; opacity: .55; }
+		#groupThumbBtn { position: relative; background: #2e7d32; color: #fff; border-color: #2e7d32; }
+		#groupThumbBtn:hover { background: #256628; }
+		#thumbBtn { position: relative; background: #1976d2; color: #fff; border-color: #1976d2; }
+		#thumbBtn:hover { background: #155fa8; }
+		#groupThumbBtn::after, #thumbBtn::after {
+			content: attr(data-tooltip); position: absolute; top: calc(100% + 8px); z-index: 30;
+			width: max-content; max-width: min(620px, calc(100vw - 24px)); padding: 6px 10px;
+			color: var(--text); font-size: 12px; font-weight: 500; line-height: 1.4; white-space: normal;
+			background: var(--panel); border: 1px solid var(--border); border-radius: 4px;
+			box-shadow: 0 4px 14px rgba(0, 0, 0, .35); pointer-events: none;
+			opacity: 0; visibility: hidden;
+		}
+		#groupThumbBtn::after { left: 0; background: #256628; border-color: #256628; color: #fff; }
+		#thumbBtn::after { right: 0; background: #155fa8; border-color: #155fa8; color: #fff; }
+		#groupThumbBtn:hover::after, #thumbBtn:hover::after { opacity: 1; visibility: visible; }
 		.thumb-dialog {
 			position: absolute; inset: 0; z-index: 40; display: flex;
 			align-items: center; justify-content: center; padding: 24px;
diff --git a/release/UNIVERSAL_SpineViewer/viewer/spine.html b/release/UNIVERSAL_SpineViewer/viewer/spine.html
index 1fb42a0..6efd566 100644
--- a/release/UNIVERSAL_SpineViewer/viewer/spine.html
+++ b/release/UNIVERSAL_SpineViewer/viewer/spine.html
@@ -29,8 +29,8 @@
 			<span data-i18n="viewer.suffix">尾缀</span>
 			<select id="suffixSelect"></select>
 		</label>
-		<button id="groupThumbBtn" data-i18n="viewer.groupThumbnail" data-i18n-title="viewer.groupThumbnailTitle" title="左键点击生成静态缩略图，右键点击生成动态缩略图">为关联资源生成缩略图</button>
-		<button id="thumbBtn" data-i18n="viewer.thumbnail" data-i18n-title="viewer.thumbnailTitle" title="左键点击生成静态缩略图，右键点击生成动态缩略图">设为当前素材缩略图</button>
+		<button id="groupThumbBtn" data-i18n="viewer.groupThumbnail" data-i18n-title="viewer.groupThumbnailTitle" data-instant-tooltip data-tooltip="左键点击生成静态缩略图，右键点击生成动态缩略图">为关联资源生成缩略图</button>
+		<button id="thumbBtn" data-i18n="viewer.thumbnail" data-i18n-title="viewer.thumbnailTitle" data-instant-tooltip data-tooltip="左键点击生成静态缩略图，右键点击生成动态缩略图">设为当前素材缩略图</button>
 		<label id="verLabel" style="color: var(--text-dim);" data-i18n-title="viewer.versionTitle" title="Spine 版本"></label>
 		<button id="reloadBtn" title="重新加载目录" data-i18n-title="viewer.reloadTitle">↻</button>
 	</div>
@@ -241,7 +241,11 @@
 	function applyStaticI18n(root) {
 		const scope = root || document;
 		for (const el of scope.querySelectorAll('[data-i18n]')) el.textContent = t(el.dataset.i18n);
-		for (const el of scope.querySelectorAll('[data-i18n-title]')) el.title = t(el.dataset.i18nTitle);
+		for (const el of scope.querySelectorAll('[data-i18n-title]')) {
+			const text = t(el.dataset.i18nTitle);
+			if (el.hasAttribute('data-instant-tooltip')) el.dataset.tooltip = text;
+			else el.title = text;
+		}
 		for (const el of scope.querySelectorAll('[data-i18n-aria-label]')) el.setAttribute('aria-label', t(el.dataset.i18nAriaLabel));
 	}
 	applyStaticI18n();
diff --git a/tests/viewer-i18n.test.js b/tests/viewer-i18n.test.js
index f646edb..9e49cf8 100644
--- a/tests/viewer-i18n.test.js
+++ b/tests/viewer-i18n.test.js
@@ -7,8 +7,21 @@ const { createRequire } = require('node:module');
 const roots = ['.', 'release/UNIVERSAL_SpineViewer'];
 for (const root of roots) {
   const html = fs.readFileSync(path.join(root, 'viewer/spine.html'), 'utf8');
+  const css = fs.readFileSync(path.join(root, 'viewer/spine.css'), 'utf8');
   const script = html.match(/<script>([\s\S]*?)<\/script>/)[1];
   new vm.Script(script);
+  for (const id of ['groupThumbBtn', 'thumbBtn']) {
+    const button = html.match(new RegExp(`<button id="${id}"[^>]*>`))[0];
+    assert.match(button, /data-instant-tooltip/);
+    assert.match(button, /data-tooltip=/);
+    assert.doesNotMatch(button, /\stitle=/);
+  }
+  assert.match(css, /#groupThumbBtn:hover::after, #thumbBtn:hover::after \{ opacity: 1; visibility: visible; \}/);
+  assert.match(css, /#groupThumbBtn \{[^}]*background: #2e7d32;/);
+  assert.match(css, /#thumbBtn \{[^}]*background: #1976d2;/);
+  assert.match(css, /#groupThumbBtn::after \{[^}]*background: #256628;/);
+  assert.match(css, /#thumbBtn::after \{[^}]*background: #155fa8;/);
+  assert.match(script, /if \(el\.hasAttribute\('data-instant-tooltip'\)\) el\.dataset\.tooltip = text;/);
   const i18n = script.slice(script.indexOf('\tconst I18N_LANGUAGES'), script.indexOf('\tapplyStaticI18n();'));
   const markers = script.slice(script.indexOf('\tfunction renderKeyframeMarkers('), script.indexOf('\tfunction seekTo('));
   const manifest = JSON.parse(fs.readFileSync(path.join(root, 'manifest.json'), 'utf8'));
diff --git a/viewer/spine.css b/viewer/spine.css
index bb4c8bc..8afc975 100644
--- a/viewer/spine.css
+++ b/viewer/spine.css
@@ -77,6 +77,21 @@
 		button.active { background: var(--accent); color: #fff; border-color: var(--accent); }
 		button.primary { background: var(--accent); color: #fff; border-color: var(--accent); }
 		button:disabled { cursor: default; opacity: .55; }
+		#groupThumbBtn { position: relative; background: #2e7d32; color: #fff; border-color: #2e7d32; }
+		#groupThumbBtn:hover { background: #256628; }
+		#thumbBtn { position: relative; background: #1976d2; color: #fff; border-color: #1976d2; }
+		#thumbBtn:hover { background: #155fa8; }
+		#groupThumbBtn::after, #thumbBtn::after {
+			content: attr(data-tooltip); position: absolute; top: calc(100% + 8px); z-index: 30;
+			width: max-content; max-width: min(620px, calc(100vw - 24px)); padding: 6px 10px;
+			color: var(--text); font-size: 12px; font-weight: 500; line-height: 1.4; white-space: normal;
+			background: var(--panel); border: 1px solid var(--border); border-radius: 4px;
+			box-shadow: 0 4px 14px rgba(0, 0, 0, .35); pointer-events: none;
+			opacity: 0; visibility: hidden;
+		}
+		#groupThumbBtn::after { left: 0; background: #256628; border-color: #256628; color: #fff; }
+		#thumbBtn::after { right: 0; background: #155fa8; border-color: #155fa8; color: #fff; }
+		#groupThumbBtn:hover::after, #thumbBtn:hover::after { opacity: 1; visibility: visible; }
 		.thumb-dialog {
 			position: absolute; inset: 0; z-index: 40; display: flex;
 			align-items: center; justify-content: center; padding: 24px;
diff --git a/viewer/spine.html b/viewer/spine.html
index 1fb42a0..6efd566 100644
--- a/viewer/spine.html
+++ b/viewer/spine.html
@@ -29,8 +29,8 @@
 			<span data-i18n="viewer.suffix">尾缀</span>
 			<select id="suffixSelect"></select>
 		</label>
-		<button id="groupThumbBtn" data-i18n="viewer.groupThumbnail" data-i18n-title="viewer.groupThumbnailTitle" title="左键点击生成静态缩略图，右键点击生成动态缩略图">为关联资源生成缩略图</button>
-		<button id="thumbBtn" data-i18n="viewer.thumbnail" data-i18n-title="viewer.thumbnailTitle" title="左键点击生成静态缩略图，右键点击生成动态缩略图">设为当前素材缩略图</button>
+		<button id="groupThumbBtn" data-i18n="viewer.groupThumbnail" data-i18n-title="viewer.groupThumbnailTitle" data-instant-tooltip data-tooltip="左键点击生成静态缩略图，右键点击生成动态缩略图">为关联资源生成缩略图</button>
+		<button id="thumbBtn" data-i18n="viewer.thumbnail" data-i18n-title="viewer.thumbnailTitle" data-instant-tooltip data-tooltip="左键点击生成静态缩略图，右键点击生成动态缩略图">设为当前素材缩略图</button>
 		<label id="verLabel" style="color: var(--text-dim);" data-i18n-title="viewer.versionTitle" title="Spine 版本"></label>
 		<button id="reloadBtn" title="重新加载目录" data-i18n-title="viewer.reloadTitle">↻</button>
 	</div>
@@ -241,7 +241,11 @@
 	function applyStaticI18n(root) {
 		const scope = root || document;
 		for (const el of scope.querySelectorAll('[data-i18n]')) el.textContent = t(el.dataset.i18n);
-		for (const el of scope.querySelectorAll('[data-i18n-title]')) el.title = t(el.dataset.i18nTitle);
+		for (const el of scope.querySelectorAll('[data-i18n-title]')) {
+			const text = t(el.dataset.i18nTitle);
+			if (el.hasAttribute('data-instant-tooltip')) el.dataset.tooltip = text;
+			else el.title = text;
+		}
 		for (const el of scope.querySelectorAll('[data-i18n-aria-label]')) el.setAttribute('aria-label', t(el.dataset.i18nAriaLabel));
 	}
 	applyStaticI18n();