diff --git a/frontend/src/components/server/TerminalDialog.tsx b/frontend/src/components/server/TerminalDialog.tsx
index 649f5d6..e1f3d59 100644
--- a/frontend/src/components/server/TerminalDialog.tsx
+++ b/frontend/src/components/server/TerminalDialog.tsx
@@ -1,4 +1,4 @@
-import { useState, useRef, useEffect } from "react";
+import { useState, useRef, useEffect, useLayoutEffect } from "react";
 import { useTranslation } from "react-i18next";
 import {
   Dialog,
@@ -173,11 +173,12 @@ export function TerminalDialog({
   // eslint-disable-next-line react-hooks/exhaustive-deps
   }, [open, serverId, authReady]);
 
-  // 容器尺寸变化时 fit 并同步远端 PTY // Logan.Li
-  useEffect(() => {
+  // 在浏览器绘制前完成 fit，避免最大化还原时短暂显示旧宽度画布。 // Logan.Li
+  useLayoutEffect(() => {
     if (!open || !authReady) return;
 
     let cleanup: (() => void) | undefined;
+    let fitFrame = 0;
     let retry = 0;
 
     const attach = () => {
@@ -190,15 +191,23 @@ export function TerminalDialog({
         return;
       }
       cleanup = attachTerminalResize(container, fit, term, ws);
-      try {
-        fitTerminal(fit, term, ws);
-      } catch {
-        /* noop */
-      }
+      const applyFit = () => {
+        try {
+          fitTerminal(fit, term, ws);
+        } catch {
+          /* noop */
+        }
+      };
+      applyFit();
+      // 下一帧再校准一次，兼容 Radix Dialog 全屏样式刚提交的场景。 // Logan.Li
+      fitFrame = requestAnimationFrame(applyFit);
     };
 
     attach();
-    return () => cleanup?.();
+    return () => {
+      if (fitFrame) cancelAnimationFrame(fitFrame);
+      cleanup?.();
+    };
   }, [open, authReady, fullscreen]);
 
   return (
@@ -208,7 +217,7 @@ export function TerminalDialog({
         // 禁用 Radix Dialog 默认的 ESC 关闭：终端内 vi/top 等会用到 ESC，关闭只能点头部 X 按钮 // Logan.Li
         onEscapeKeyDown={(e) => e.preventDefault()}
         className={cn(
-          "bg-[var(--dg-bg-secondary)] border-[var(--dg-border)] p-0 gap-0",
+          "min-w-0 overflow-hidden bg-[var(--dg-bg-secondary)] border-[var(--dg-border)] p-0 gap-0",
           // 禁用 CSS 过渡：终端窗口应该即时缩放，不需要动画
           "!duration-0 !transition-none",
           fullscreen
@@ -239,7 +248,7 @@ export function TerminalDialog({
           </div>
           <div className="flex items-center gap-1">
             <button
-              onClick={() => setFullscreen(!fullscreen)}
+              onClick={() => setFullscreen((current) => !current)}
               className="p-1.5 rounded hover:bg-[var(--dg-bg-hover)] text-[var(--dg-text-secondary)]"
             >
               {fullscreen ? (
@@ -301,10 +310,13 @@ export function TerminalDialog({
         {/* 终端容器 */}
         {authReady && (
           <div
-            className="relative bg-[#0a0e14]"
+            className="relative min-w-0 overflow-hidden bg-[#0a0e14]"
             style={{ height: fullscreen ? "calc(100vh - 49px)" : "520px" }}
           >
-            <div ref={containerRef} className="xterm-terminal-host h-full" />
+            <div
+              ref={containerRef}
+              className="xterm-terminal-host h-full min-w-0"
+            />
             <SessionWatermark className="opacity-60" />
             <TerminalLoadingOverlay
               show={!hasOutput}