优化输出格式，调整打印对齐和分隔符

cmd/nodeprobe/main.go

@@ -4,6 +4,7 @@ import (
 	"fmt"
 	"os"
 	"os/signal"
+	"strings"
 	"syscall"
 	"time"
 
@@ -88,10 +89,10 @@ func moveCursorToTop() {
 
 func printHeader() {
 	fmt.Println("Network Interface Traffic Monitor")
-	fmt.Println("----------------------------------")
-	fmt.Printf("%-20s %30s %30s %15s %15s\n",
+	fmt.Println("=", strings.Repeat("=", 120))
+	fmt.Printf("%-20s %-30s %-30s %-20s %-20s\n",
 		"Interface", "Download", "Upload", "RX Total", "TX Total")
-	fmt.Println("----------------------------------")
+	fmt.Println("=", strings.Repeat("=", 120))
 }
 
 func printStats(rates []netstat.TrafficRate, stats []netstat.InterfaceStats) {
@@ -122,7 +123,7 @@ func printStats(rates []netstat.TrafficRate, stats []netstat.InterfaceStats) {
 		rxBar := makeTrafficBar(r.RxKbps*1000, maxRate, true)
 		txBar := makeTrafficBar(r.TxKbps*1000, maxRate, false)
 
-		fmt.Printf("%-20s %30s %30s %15s %15s\n",
+		fmt.Printf("%-20s %-30s %-30s %-20s %-20s\n",
 			r.Name,
 			rxBar,
 			txBar,
@@ -168,5 +169,5 @@ func makeTrafficBar(bps, maxBps float64, isDownload bool) string {
 	// 格式化速率信息
 	speedStr := netstat.FormatBps(bps)
 
-	return fmt.Sprintf("%s%s%s %9s", color, bar, reset, speedStr)
+	return fmt.Sprintf("%s%s%s %s", color, bar, reset, speedStr)
 }