diff --git a/feature/roaming/src/main/java/com/rtbishop/look4sat/feature/roaming/RoamingScreen.kt b/feature/roaming/src/main/java/com/rtbishop/look4sat/feature/roaming/RoamingScreen.kt
index 7c7738a9..1585559b 100644
--- a/feature/roaming/src/main/java/com/rtbishop/look4sat/feature/roaming/RoamingScreen.kt
+++ b/feature/roaming/src/main/java/com/rtbishop/look4sat/feature/roaming/RoamingScreen.kt
@@ -17,13 +17,23 @@
  */
 package com.rtbishop.look4sat.feature.roaming
 
+import android.Manifest
+import android.annotation.SuppressLint
+import android.content.Context
+import android.content.Intent
+import android.content.pm.PackageManager
+import android.location.Location
+import android.location.LocationListener
+import android.location.LocationManager
+import android.os.Bundle
+import android.provider.Settings
+import androidx.activity.compose.rememberLauncherForActivityResult
+import androidx.activity.result.contract.ActivityResultContracts
+import androidx.compose.foundation.Image
 import androidx.compose.foundation.background
-import androidx.compose.foundation.border
-import androidx.compose.foundation.layout.Arrangement
+import androidx.compose.foundation.clickable
 import androidx.compose.foundation.layout.Box
-import androidx.compose.foundation.layout.BoxWithConstraints
 import androidx.compose.foundation.layout.Column
-import androidx.compose.foundation.layout.ColumnScope
 import androidx.compose.foundation.layout.Row
 import androidx.compose.foundation.layout.Spacer
 import androidx.compose.foundation.layout.fillMaxHeight
@@ -34,304 +44,736 @@ import androidx.compose.foundation.layout.offset
 import androidx.compose.foundation.layout.padding
 import androidx.compose.foundation.layout.size
 import androidx.compose.foundation.layout.width
-import androidx.compose.foundation.shape.CircleShape
-import androidx.compose.material3.Divider
-import androidx.compose.material3.MaterialTheme
+import androidx.compose.material3.CircularProgressIndicator
 import androidx.compose.material3.Text
 import androidx.compose.runtime.Composable
+import androidx.compose.runtime.DisposableEffect
 import androidx.compose.runtime.LaunchedEffect
 import androidx.compose.runtime.getValue
-import androidx.compose.runtime.mutableLongStateOf
+import androidx.compose.runtime.mutableStateOf
 import androidx.compose.runtime.remember
 import androidx.compose.runtime.setValue
 import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
-import androidx.compose.ui.draw.clip
 import androidx.compose.ui.graphics.Color
 import androidx.compose.ui.platform.LocalContext
-import androidx.compose.ui.platform.LocalDensity
-import androidx.compose.ui.text.font.FontFamily
+import androidx.compose.ui.res.painterResource
 import androidx.compose.ui.text.font.FontWeight
 import androidx.compose.ui.text.style.TextAlign
 import androidx.compose.ui.unit.dp
 import androidx.compose.ui.unit.sp
-import androidx.lifecycle.compose.collectAsStateWithLifecycle
-import com.rtbishop.look4sat.core.domain.repository.IContainerProvider
-import com.rtbishop.look4sat.core.presentation.LocalSpacing
-import com.rtbishop.look4sat.core.presentation.ScreenColumn
-import com.rtbishop.look4sat.core.presentation.TopBar
+import androidx.core.content.ContextCompat
 import java.text.SimpleDateFormat
 import java.util.Date
 import java.util.Locale
 
 /**
- * Roaming (漫游) page: a faithful port of the QTH定位器 location panel —
- * GPS status + date/time header, DMS & decimal coordinates, the big 8-char
- * Maidenhead locator, and a 3x3 grid of neighboring squares (center column
- * and row are wider/taller, matching the reference app). Styled with the
- * Look4Sat Material 3 theme.
- *
- * Coordinates are read straight from the shared settingsRepo.stationPosition
- * StateFlow — the same source the Settings page uses — so the page shows
- * exactly the station position (站位), whatever the GPS says there. No
- * automatic location polling on this page.
+ * 漫游页 —— 原样照搬自 QTH定位器 2.0 (com.us1pm.gridsquarelocator)。
+ * UI: res/layout/main.xml (结构/尺寸/颜色逐项照搬, 不做任何更改)
+ * 逻辑: MainActivity.showLocation() / checkEnabled() / GPS 实时监听
+ * 红线: UI 与逻辑均不更改, 与成品截图逐像素对齐。
  */
 @Composable
 fun RoamingScreen() {
     val context = LocalContext.current
-    val container = (context.applicationContext as IContainerProvider).getMainContainer()
-    val stationPos by container.settingsRepo.stationPosition.collectAsStateWithLifecycle()
-
-    val state = remember(stationPos) {
-        RoamingState.fromPosition(stationPos)
-    }
-
-    // Clock ticker: re-render date/time every second so the header clock
-    // actually moves (the reference app refreshes it on every location fix).
-    var now by remember { mutableLongStateOf(System.currentTimeMillis()) }
+    var state by remember { mutableStateOf(RoamingState()) }
+    // 照搬 onCreate: 日期固定文本 + 小时前缀(定位时拼接分钟)
+    val dateText = remember { SimpleDateFormat("dd MMM yyyy", Locale.getDefault()).format(Date()) }
+    var hourPrefix by remember { mutableStateOf("") }
+    // 照搬 onCreate: 初始 checkEnabled() -> 红点+设置按钮, 日期隐藏
+    var hasPermission by remember { mutableStateOf(false) }
+    val permissionLauncher = rememberLauncherForActivityResult(
+        ActivityResultContracts.RequestMultiplePermissions()
+    ) { }
     LaunchedEffect(Unit) {
-        while (true) {
-            now = System.currentTimeMillis()
-            kotlinx.coroutines.delay(1_000L)
+        hourPrefix = SimpleDateFormat("HH:mm", Locale.getDefault()).format(Date()).substring(0, 3)
+        val fine = ContextCompat.checkSelfPermission(context, Manifest.permission.ACCESS_FINE_LOCATION) ==
+            PackageManager.PERMISSION_GRANTED
+        val coarse = ContextCompat.checkSelfPermission(context, Manifest.permission.ACCESS_COARSE_LOCATION) ==
+            PackageManager.PERMISSION_GRANTED
+        hasPermission = fine || coarse
+        if (!hasPermission) {
+            permissionLauncher.launch(
+                arrayOf(Manifest.permission.ACCESS_FINE_LOCATION, Manifest.permission.ACCESS_COARSE_LOCATION)
+            )
+        } else {
+            // 照搬 onResume: 绿点+进度条+提示+日期显示, 红点/按钮隐藏
+            state = state.copy(gpsOn = true, gpsOff = false, showSettings = false, showProgress = true, showNotice = true, showDate = true)
         }
     }
+    // 照搬 onResume/onPause: GPS + network 监听, 10 秒 / 10 米
+    val locationManager = remember { context.getSystemService(Context.LOCATION_SERVICE) as LocationManager }
+    DisposableEffect(locationManager, hasPermission) {
+        if (hasPermission) {
+            @SuppressLint("MissingPermission")
+            val listener = object : LocationListener {
+                override fun onLocationChanged(location: Location) {
+                    // 照搬 showLocation 开头: 只接受 gps / network provider
+                    if (location.provider != "gps" && location.provider != "network") return
+                    state = roamingStateFromLocation(location.latitude, location.longitude, location.time, hourPrefix)
+                        .copy(date = dateText)
+                }
 
-    ScreenColumn(
-        topBar = {
-            TopBar { Text(text = "漫游", fontSize = 20.sp, fontWeight = FontWeight.Bold) }
+                override fun onProviderDisabled(provider: String) {
+                    // 照搬 checkEnabled: 红点+按钮, 日期隐藏
+                    state = state.copy(gpsOn = false, gpsOff = true, showSettings = true, showProgress = false, showNotice = false, showDate = false)
+                }
+
+                override fun onProviderEnabled(provider: String) {
+                    state = state.copy(gpsOn = true, gpsOff = false, showSettings = false, showProgress = true, showNotice = true, showDate = true)
+                }
+
+                @Deprecated("Deprecated in Java")
+                override fun onStatusChanged(provider: String?, status: Int, extras: Bundle?) = Unit
+            }
+            try {
+                locationManager.requestLocationUpdates("gps", 10_000L, 10f, listener)
+                locationManager.requestLocationUpdates("network", 10_000L, 10f, listener)
+            } catch (_: SecurityException) {
+            }
+            onDispose { locationManager.removeUpdates(listener) }
+        } else {
+            onDispose { }
         }
-    ) {
-        val spacing = LocalSpacing.current
-        Column(
-            modifier = Modifier.fillMaxSize(),
-            verticalArrangement = Arrangement.spacedBy(spacing.medium)
+    }
+    // 照搬 res/layout/main.xml: 浅色页面, 蓝色信息区, 43sp 定位码, 3x3 九宫格, 底部版权
+    Column(modifier = Modifier.fillMaxSize().background(Color(0xFFF2F2F2))) {
+        // relativeLayout7: 顶部 GPS 状态条, 25dp 高, holo_blue_bright
+        Box(
+            modifier = Modifier
+                .fillMaxWidth()
+                .padding(2.dp)
+                .height(25.dp)
+                .background(Color(0xFF01DDFF))
         ) {
-            InfoCard(state = state, now = now)
-            GridCard(state = state, modifier = Modifier.weight(1f))
+            Row(modifier = Modifier.fillMaxSize(), verticalAlignment = Alignment.CenterVertically) {
+                // tvTitleGPS: "GPS" 14sp 黑, 左 8dp
+                Text(
+                    text = "GPS",
+                    fontSize = 14.sp,
+                    color = Color.Black,
+                    modifier = Modifier.padding(start = 8.dp)
+                )
+                // imGps: toRightOf tvTitleGPS + marginLeft 15dp (成品 main.xml)
+                Spacer(modifier = Modifier.width(15.dp))
+                // imGps: 绿点 (15dp)
+                if (state.gpsOn) {
+                    Image(
+                        painter = painterResource(R.drawable.roam_gps_green),
+                        contentDescription = null,
+                        modifier = Modifier.size(15.dp)
+                    )
+                }
+                // imGpsOff: 红点叠层 (15dp)
+                if (state.gpsOff) {
+                    Image(
+                        painter = painterResource(R.drawable.roam_gps_red),
+                        contentDescription = null,
+                        modifier = Modifier.size(15.dp)
+                    )
+                }
+                Spacer(modifier = Modifier.weight(1f))
+                // tvDate: 14sp 黑, 居中
+                if (state.showDate) {
+                    Text(text = state.date.ifEmpty { dateText }, fontSize = 14.sp, color = Color.Black)
+                }
+                Spacer(modifier = Modifier.weight(1f))
+                // tvTime: 14sp 黑, 右对齐
+                Text(
+                    text = state.time,
+                    fontSize = 14.sp,
+                    color = Color.Black,
+                    modifier = Modifier.padding(end = 8.dp)
+                )
+            }
+            // btnLocationSettings: 黄色按钮, 居中
+            // btnLocationSettings: 成品 #faf8f54a 半透明黄, 14sp 黑字, 居中
+            if (state.showSettings) {
+                Box(
+                    modifier = Modifier
+                        .align(Alignment.Center)
+                        .background(Color(0xFAF8F54A))
+                        .clickable { context.startActivity(Intent(Settings.ACTION_LOCATION_SOURCE_SETTINGS)) }
+                        .padding(horizontal = 5.dp),
+                    contentAlignment = Alignment.Center
+                ) {
+                    Text(text = "设置启用GPS", fontSize = 14.sp, color = Color.Black)
+                }
+            }
         }
-    }
-}
-
-@Composable
-private fun InfoCard(state: RoamingState, now: Long) {
-    val colorScheme = MaterialTheme.colorScheme
-    Column(
-        modifier = Modifier
-            .fillMaxWidth()
-            .background(colorScheme.secondaryContainer)
-            .padding(horizontal = 16.dp, vertical = 12.dp),
-        verticalArrangement = Arrangement.spacedBy(8.dp)
-    ) {
-        // Top bar: GPS status + date + time
-        Row(verticalAlignment = Alignment.CenterVertically) {
-            Text(
-                text = "GPS",
-                fontSize = 16.sp,
-                fontWeight = FontWeight.Medium,
-                color = colorScheme.onSecondaryContainer
-            )
-            Spacer(modifier = Modifier.width(6.dp))
-            Box(
-                modifier = Modifier
-                    .size(10.dp)
-                    .clip(CircleShape)
-                    .background(if (state.gpsEnabled) colorScheme.primary else colorScheme.outline)
-            )
-            Spacer(modifier = Modifier.weight(1f))
-            Text(
-                text = SimpleDateFormat("dd MMM yyyy", Locale.getDefault()).format(Date(now)),
-                fontSize = 14.sp,
-                color = colorScheme.onSecondaryContainer
-            )
-            Spacer(modifier = Modifier.width(12.dp))
-            Text(
-                text = SimpleDateFormat("HH:mm", Locale.getDefault()).format(Date(now)),
-                fontSize = 16.sp,
-                fontWeight = FontWeight.Medium,
-                color = colorScheme.onSecondaryContainer
-            )
+        // linearLayout4: 经纬度区, holo_blue_bright
+        Column(
+            modifier = Modifier
+                .fillMaxWidth()
+                .padding(horizontal = 2.dp)
+                .background(Color(0xFF01DDFF))
+        ) {
+            // 纬度行: tvLati 16sp 黑 左 8dp | tvLat 右对齐 3dp
+            Row(modifier = Modifier.fillMaxWidth().padding(vertical = 2.dp), verticalAlignment = Alignment.CenterVertically) {
+                Text(text = state.latLabel, fontSize = 16.sp, color = Color.Black, modifier = Modifier.padding(start = 8.dp))
+                Spacer(modifier = Modifier.weight(1f))
+                Text(text = state.latValue, fontSize = 14.sp, color = Color.Black, modifier = Modifier.padding(end = 3.dp))
+            }
+            // 经度行
+            Row(modifier = Modifier.fillMaxWidth().padding(vertical = 2.dp), verticalAlignment = Alignment.CenterVertically) {
+                Text(text = state.lonLabel, fontSize = 16.sp, color = Color.Black, modifier = Modifier.padding(start = 8.dp))
+                Spacer(modifier = Modifier.weight(1f))
+                Text(text = state.lonValue, fontSize = 14.sp, color = Color.Black, modifier = Modifier.padding(end = 3.dp))
+            }
         }
-        // Coordinates: DMS + decimal
-        CoordinateRow(label = "纬度", value = state.latitude, isLat = true)
-        CoordinateRow(label = "经度", value = state.longitude, isLat = false)
-        // Big locator, centered
+        // relativeLayout6: 定位码区, 43sp bold 黑居中
+        Box(
+            modifier = Modifier
+                .fillMaxWidth()
+                .padding(2.dp)
+                .background(Color(0xFF01DDFF))
+        ) {
+            Text(
+                text = state.loc,
+                fontSize = 43.sp,
+                fontWeight = FontWeight.Bold,
+                color = Color.Black,
+                textAlign = TextAlign.Center,
+                modifier = Modifier.fillMaxWidth()
+            )
+            // progressBar: 加载中, 居中
+            if (state.showProgress) {
+                CircularProgressIndicator(
+                    modifier = Modifier.size(24.dp).align(Alignment.Center),
+                    color = Color.Black,
+                    strokeWidth = 2.dp
+                )
+            }
+            // tvNotice: 提示文字, 居中顶部
+            if (state.showNotice) {
+                Text(
+                    text = "请稍等，加载可能需要几分钟的时间。",
+                    fontSize = 16.sp,
+                    fontStyle = androidx.compose.ui.text.font.FontStyle.Italic,
+                    color = Color.Black,
+                    modifier = Modifier.align(Alignment.TopCenter).padding(top = 2.dp)
+                )
+            }
+        }
+        // relativeLayout: 九宫格, 占满剩余, 底部 15dp
+        Column(modifier = Modifier.fillMaxWidth().weight(1f).padding(bottom = 15.dp)) {
+            // 行1: relativeLayout5 (上排: 纬度 +1)
+            Row(modifier = Modifier.fillMaxWidth().weight(1f)) {
+                GridCell(text = state.grids[0], modifier = Modifier.width(60.dp).fillMaxHeight())
+                GridCell(text = state.grids[1], modifier = Modifier.width(200.dp).fillMaxHeight())
+                GridCell(text = state.grids[2], modifier = Modifier.width(60.dp).fillMaxHeight())
+            }
+            // 行2: relativeLayout4, 205dp 高 (中排: 中央)
+            Row(modifier = Modifier.fillMaxWidth().height(205.dp)) {
+                GridCell(text = state.grids[3], modifier = Modifier.width(60.dp).fillMaxHeight())
+                // 中央列: tv22 (100x80dp centerInParent) 叠在 linearLayout3 (200x200dp) 之上
+                Box(modifier = Modifier.width(200.dp).fillMaxHeight()) {
+                    // linearLayout3: 200x200dp, marginTop 2dp, holo_blue_bright
+                    Box(
+                        modifier = Modifier
+                            .align(Alignment.TopCenter)
+                            .offset(y = 2.dp)
+                            .size(width = 200.dp, height = 200.dp)
+                            .background(Color(0xFF01DDFF))
+                    ) {
+                        // iv: 红点 10x10dp, top|left, leftMargin/topMargin 查表绝对定位
+                        Image(
+                            painter = painterResource(R.drawable.roam_pnt),
+                            contentDescription = null,
+                            modifier = Modifier
+                                .size(10.dp)
+                                .offset(x = state.markerLeft.dp, y = state.markerTop.dp)
+                        )
+                    }
+                    // tv22: 100x80dp centerInParent, 30sp bold, textColorHighlight(白)
+                    Text(
+                        text = state.grids[4],
+                        fontSize = 30.sp,
+                        fontWeight = FontWeight.Bold,
+                        color = Color.White,
+                        textAlign = TextAlign.Center,
+                        modifier = Modifier
+                            .size(width = 100.dp, height = 80.dp)
+                            .align(Alignment.Center)
+                    )
+                }
+                GridCell(text = state.grids[5], modifier = Modifier.width(60.dp).fillMaxHeight())
+            }
+            // 行3: relativeLayout3 (下排: 纬度 -1)
+            Row(modifier = Modifier.fillMaxWidth().weight(1f)) {
+                GridCell(text = state.grids[6], modifier = Modifier.width(60.dp).fillMaxHeight())
+                GridCell(text = state.grids[7], modifier = Modifier.width(200.dp).fillMaxHeight())
+                GridCell(text = state.grids[8], modifier = Modifier.width(60.dp).fillMaxHeight())
+            }
+        }
+        // tv4: 底部版权, 10sp 黑, 15dp 高
         Text(
-            text = state.qthLocator,
-            fontSize = 34.sp,
-            fontWeight = FontWeight.Bold,
-            fontFamily = FontFamily.Monospace,
-            color = colorScheme.onSecondaryContainer,
+            text = "制作：US1PM  汉化：BA7LCE",
+            fontSize = 10.sp,
+            color = Color.Black,
             textAlign = TextAlign.Center,
-            modifier = Modifier.fillMaxWidth()
+            modifier = Modifier.fillMaxWidth().height(15.dp)
         )
     }
 }
 
+// 周边格: 60/200/60dp, #0BACF1, bold 居中, 2dp margin (照搬 tv11/tv13/tv21/tv23/tv31/tv33)
 @Composable
-private fun CoordinateRow(label: String, value: Double, isLat: Boolean) {
-    val colorScheme = MaterialTheme.colorScheme
-    Row(verticalAlignment = Alignment.CenterVertically, modifier = Modifier.fillMaxWidth()) {
+private fun GridCell(text: String, modifier: Modifier) {
+    Box(
+        modifier = modifier
+            .padding(2.dp)
+            .background(Color(0xFF0BACF1)),
+        contentAlignment = Alignment.Center
+    ) {
         Text(
-            text = label,
-            fontSize = 15.sp,
-            fontWeight = FontWeight.Medium,
-            color = colorScheme.onSurface,
-            modifier = Modifier.width(40.dp)
-        )
-        Text(text = formatDms(value, isLat), fontSize = 15.sp, color = colorScheme.onSurface)
-        Spacer(modifier = Modifier.weight(1f))
-        Text(
-            text = "${formatDecimal(value)}°",
+            text = text,
             fontSize = 14.sp,
-            color = colorScheme.onSurfaceVariant
+            fontWeight = FontWeight.Bold,
+            color = Color.Black,
+            textAlign = TextAlign.Center
         )
     }
 }
 
 /**
- * 3x3 grid of 4-char squares — a faithful continuous-table port: no outer
- * card, no rounded cells, no gaps. Cells are connected edge-to-edge and
- * separated by thin divider lines (crossing at right angles like a real
- * coordinate grid). Column widths 21.4% : 56.2% : 21.4%, row heights
- * 31.5% : 35.9% : 31.7% mirror the reference app: the center column is
- * ~2.6x wider and the center row is the tallest, so the current square
- * dominates the panel.
+ * 照搬 MainActivity.showLocation() 的状态。
+ * 网格/九宫格/红点查表与成品逐行一致。
  */
-@Composable
-private fun GridCard(state: RoamingState, modifier: Modifier = Modifier) {
-    val colorScheme = MaterialTheme.colorScheme
-    val dividerColor = colorScheme.outline
-    Column(
-        modifier = modifier
-            .fillMaxSize()
-            .border(2.dp, dividerColor)
-    ) {
-        GridRow(state, row = 0, weight = 0.315f, dividerColor = dividerColor)
-        Divider(color = dividerColor, thickness = 2.dp)
-        GridRow(state, row = 1, weight = 0.359f, dividerColor = dividerColor)
-        Divider(color = dividerColor, thickness = 2.dp)
-        GridRow(state, row = 2, weight = 0.317f, dividerColor = dividerColor)
+data class RoamingState(
+    val date: String = "",
+    val time: String = "",
+    val latLabel: String = "纬度",
+    val latValue: String = "",
+    val lonLabel: String = "经度",
+    val lonValue: String = "",
+    val loc: String = "",
+    val grids: List<String> = List(9) { "" },
+    /** 红点 leftMargin(dp), 经度第 3 对字符查表 */
+    val markerLeft: Int = 0,
+    /** 红点 topMargin(dp), 纬度第 3 对字符查表(屏幕 Y 反转) */
+    val markerTop: Int = 0,
+    val gpsOn: Boolean = false,
+    val gpsOff: Boolean = true,
+    val showSettings: Boolean = true,
+    val showProgress: Boolean = false,
+    val showNotice: Boolean = false,
+    val showDate: Boolean = false
+)
+
+/**
+ * 照搬 showLocation() 的完整计算: 时间/经纬度 DMS/8 位网格/九宫格/红点查表。
+ */
+fun roamingStateFromLocation(lat: Double, lon: Double, fixTime: Long, hourPrefix: String): RoamingState {
+    // 照搬: tvTime = 缓存小时前缀 + 定位时间分钟
+    val minute = SimpleDateFormat("mm", Locale.getDefault()).format(Date(fixTime))
+    val time = hourPrefix + minute
+    // 方向字符
+    val ew = if (lon >= 0.0) "E" else "W"
+    val ns = if (lat >= 0.0) "N" else "S"
+    // 照搬: 纬度 DMS (String.valueOf 无补零)
+    val latAbs = if (lat < 0.0) -lat else lat
+    val latDeg = latAbs.toInt()
+    val latMinFull = (latAbs - latDeg) * 60.0
+    val latMin = latMinFull.toInt()
+    val latSec = ((latMinFull - latMin) * 60.0).toInt()
+    val latLabel = "纬度  $latDeg° $latMin' $latSec\" $ns"
+    val latValue = "$lat° "
+    // 照搬: 经度 DMS
+    val lonAbs = if (lon < 0.0) -lon else lon
+    val lonDeg = lonAbs.toInt()
+    val lonMinFull = (lonAbs - lonDeg) * 60.0
+    val lonMin = lonMinFull.toInt()
+    val lonSec = ((lonMinFull - lonMin) * 60.0).toInt()
+    val lonLabel = "经度 $lonDeg° $lonMin' $lonSec\" $ew"
+    val lonValue = "$lon° "
+    // 照搬: 8 位网格编码 (区间查表)
+    val (str, str2, str3, str4) = encodeLon(lon)
+    val (str5, str6, str38, str9) = encodeLat(lat)
+    val loc = str + str5 + str2 + str6 + str3 + str38 + str4 + str9
+    // 照搬: 九宫格 parseInt3 五分支
+    val grids = buildGrids(str, str5, str2, str6, str3, str38)
+    // 照搬: 红点查表 (第 3 对字符)
+    val markerLeft = lonMargin[str3.firstOrNull()] ?: 0
+    val markerTop = latMargin[str38.firstOrNull()] ?: 0
+    return RoamingState(
+        time = time,
+        latLabel = latLabel,
+        latValue = latValue,
+        lonLabel = lonLabel,
+        lonValue = lonValue,
+        loc = loc,
+        grids = grids,
+        markerLeft = markerLeft,
+        markerTop = markerTop,
+        gpsOn = true,
+        gpsOff = false,
+        showSettings = false,
+        showProgress = false,
+        showNotice = false,
+        showDate = true
+    )
+}
+
+// 红点 leftMargin 查表 (MainActivity 1286-1386 行): 经度第 3 对 a..x -> -2..190 dp
+private val lonMargin = mapOf(
+    'a' to -2, 'b' to 8, 'c' to 16, 'd' to 24, 'e' to 32, 'f' to 40, 'g' to 48, 'h' to 56,
+    'i' to 65, 'j' to 74, 'k' to 83, 'l' to 92, 'm' to 101, 'n' to 110, 'o' to 119, 'p' to 128,
+    'q' to 137, 'r' to 146, 's' to 155, 't' to 163, 'u' to 171, 'v' to 179, 'w' to 184, 'x' to 190
+)
+
+// 红点 topMargin 查表 (MainActivity 1315-1363 行): 纬度第 3 对 a..x -> 190..-2 dp (屏幕 Y 反转)
+private val latMargin = mapOf(
+    'a' to 190, 'b' to 182, 'c' to 174, 'd' to 169, 'e' to 163, 'f' to 155, 'g' to 146, 'h' to 137,
+    'i' to 128, 'j' to 119, 'k' to 110, 'l' to 101, 'm' to 92, 'n' to 83, 'o' to 74, 'p' to 65,
+    'q' to 56, 'r' to 48, 's' to 40, 't' to 32, 'u' to 24, 'v' to 16, 'w' to 8, 'x' to -2
+)
+
+// 照搬 311-611 行: 经度 -> (20°区字母, 2°数字, 2'字母, 30"数字)
+private fun encodeLon(inputLon: Double): List<String> {
+    var longitude = inputLon
+    var d = 0.0
+    val str = when {
+        (longitude >= -180.0) && (longitude <= -160.0) -> { longitude += 180.0; "A" }
+        (longitude >= -160.0) && (longitude <= -140.0) -> { longitude += 160.0; "B" }
+        (longitude >= -140.0) && (longitude <= -120.0) -> { longitude += 140.0; "C" }
+        (longitude >= -120.0) && (longitude <= -100.0) -> { longitude += 120.0; "D" }
+        (longitude >= -100.0) && (longitude <= -80.0) -> { longitude += 100.0; "E" }
+        (longitude >= -80.0) && (longitude <= -60.0) -> { longitude += 80.0; "F" }
+        (longitude >= -60.0) && (longitude <= -40.0) -> { longitude += 60.0; "G" }
+        (longitude >= -40.0) && (longitude <= -20.0) -> { longitude += 40.0; "H" }
+        (longitude >= -20.0) && (longitude <= 0.0) -> { longitude += 20.0; "I" }
+        (longitude >= 0.0) && (longitude <= 20.0) -> "J"
+        (longitude >= 20.0) && (longitude <= 40.0) -> { longitude -= 20.0; "K" }
+        (longitude >= 40.0) && (longitude <= 60.0) -> { longitude -= 40.0; "L" }
+        (longitude >= 60.0) && (longitude <= 80.0) -> { longitude -= 60.0; "M" }
+        (longitude >= 80.0) && (longitude <= 100.0) -> { longitude -= 80.0; "N" }
+        (longitude >= 100.0) && (longitude <= 120.0) -> { longitude -= 100.0; "O" }
+        (longitude >= 120.0) && (longitude <= 140.0) -> { longitude -= 120.0; "P" }
+        (longitude >= 140.0) && (longitude <= 160.0) -> { longitude -= 140.0; "Q" }
+        (longitude >= 160.0) && (longitude <= 180.0) -> { longitude -= 160.0; "R" }
+        else -> { longitude = 0.0; " " }
     }
-}
-
-@Composable
-private fun ColumnScope.GridRow(
-    state: RoamingState,
-    row: Int,
-    weight: Float,
-    dividerColor: Color
-) {
-    Row(
-        modifier = Modifier
-            .fillMaxWidth()
-            .weight(weight)
-    ) {
-        GridCell(
-            label = state.gridSquares.getOrElse(row * 3 + 0) { "----" },
-            isCenter = false,
-            dividerColor = dividerColor,
-            modifier = Modifier.weight(0.214f)
-        )
-        Divider(
-            color = dividerColor, thickness = 2.dp,
-            modifier = Modifier.fillMaxHeight().width(2.dp)
-        )
-        GridCell(
-            label = state.gridSquares.getOrElse(row * 3 + 1) { "----" },
-            isCenter = row == 1,
-            markerX = state.markerX,
-            markerY = state.markerY,
-            showMarker = row == 1 && state.qthLocator != "----",
-            dividerColor = dividerColor,
-            modifier = Modifier.weight(0.562f)
-        )
-        Divider(
-            color = dividerColor, thickness = 2.dp,
-            modifier = Modifier.fillMaxHeight().width(2.dp)
-        )
-        GridCell(
-            label = state.gridSquares.getOrElse(row * 3 + 2) { "----" },
-            isCenter = false,
-            dividerColor = dividerColor,
-            modifier = Modifier.weight(0.214f)
-        )
+    val str2 = when {
+        ((longitude >= 0.0) && (longitude <= 2.0)) || ((longitude >= -20.0) && (longitude <= -18.0)) -> { d = longitude * 60.0; "0" }
+        ((longitude >= 2.0) && (longitude <= 4.0)) || ((longitude >= -18.0) && (longitude <= -16.0)) -> { d = (longitude - 2.0) * 60.0; "1" }
+        ((longitude >= 4.0) && (longitude <= 6.0)) || ((longitude >= -16.0) && (longitude <= -14.0)) -> { d = (longitude - 4.0) * 60.0; "2" }
+        ((longitude >= 6.0) && (longitude <= 8.0)) || ((longitude >= -14.0) && (longitude <= -12.0)) -> { d = (longitude - 6.0) * 60.0; "3" }
+        ((longitude >= 8.0) && (longitude <= 10.0)) || ((longitude >= -12.0) && (longitude <= -10.0)) -> { d = (longitude - 8.0) * 60.0; "4" }
+        ((longitude >= 10.0) && (longitude <= 12.0)) || ((longitude >= -10.0) && (longitude <= -8.0)) -> { d = (longitude - 10.0) * 60.0; "5" }
+        ((longitude >= 12.0) && (longitude <= 14.0)) || ((longitude >= -8.0) && (longitude <= -6.0)) -> { d = (longitude - 12.0) * 60.0; "6" }
+        ((longitude >= 14.0) && (longitude <= 16.0)) || ((longitude >= -6.0) && (longitude <= -4.0)) -> { d = (longitude - 14.0) * 60.0; "7" }
+        ((longitude >= 16.0) && (longitude <= 18.0)) || ((longitude >= -4.0) && (longitude <= -2.0)) -> { d = (longitude - 16.0) * 60.0; "8" }
+        ((longitude >= 18.0) && (longitude <= 20.0)) || ((longitude >= -2.0) && (longitude <= 0.0)) -> { d = (longitude - 18.0) * 60.0; "9" }
+        else -> { d = 0.0; " " }
     }
-}
-
-@Composable
-private fun GridCell(
-    label: String,
-    isCenter: Boolean,
-    markerX: Float = 0.5f,
-    markerY: Float = 0.5f,
-    showMarker: Boolean = false,
-    dividerColor: Color,
-    modifier: Modifier = Modifier
-) {
-    val colorScheme = MaterialTheme.colorScheme
-    val cellBackground = if (isCenter) colorScheme.secondaryContainer else colorScheme.surfaceVariant
-    val labelColor = if (isCenter) colorScheme.onSecondaryContainer else colorScheme.onSurfaceVariant
-    BoxWithConstraints(
-        modifier = modifier
-            .fillMaxSize()
-            .background(cellBackground)
-    ) {
-        // Capture constraints at the BoxWithConstraints scope (Column scope would shadow them)
-        val width = maxWidth
-        val height = maxHeight
-        if (isCenter) {
-            // Center cell, faithful to the reference app: the locator label
-            // sits at the upper-middle and the red marker is positioned by
-            // (markerX, markerY) — both derived from the 3rd character pair
-            // via the reference lookup tables (lon a=-2..x=190, lat a=190..x=-2
-            // as topMargin, i.e. latitude inverted on screen). The marker
-            // therefore tracks the fix inside the 4-char square in BOTH axes.
-            val density = LocalDensity.current
-            val dotSize = 14.dp
-            // Marker top-left from the cell's top-left corner:
-            // x = markerX * cellWidth, y = markerY * cellHeight (screen Y).
-            if (showMarker) {
-                val markerOffsetX = with(density) { (width * markerX).toPx().toDp() - dotSize / 2 }
-                val markerOffsetY = with(density) { (height * markerY).toPx().toDp() - dotSize / 2 }
-                Box(
-                    modifier = Modifier
-                        .size(dotSize)
-                        .background(colorScheme.error)
-                        .offset(x = markerOffsetX, y = markerOffsetY)
-                )
-            }
-            // Label above the marker, upper-middle of the cell
-            Text(
-                text = label,
-                fontSize = 28.sp,
-                fontWeight = FontWeight.Bold,
-                color = labelColor,
-                textAlign = TextAlign.Center,
-                modifier = Modifier
-                    .align(Alignment.TopCenter)
-                    .padding(top = 8.dp)
-            )
-        } else {
-            Text(
-                text = label,
-                fontSize = 16.sp,
-                fontWeight = FontWeight.Medium,
-                color = labelColor,
-                textAlign = TextAlign.Center,
-                modifier = Modifier.align(Alignment.Center)
-            )
-        }
+    val str3 = when {
+        ((d >= 0.0) && (d <= 5.0)) || ((d >= -120.0) && (d <= -115.0)) -> { longitude = d * 60.0; "a" }
+        ((d >= 5.0) && (d <= 10.0)) || ((d >= -115.0) && (d <= -110.0)) -> { longitude = (d - 5.0) * 60.0; "b" }
+        ((d >= 10.0) && (d <= 15.0)) || ((d >= -110.0) && (d <= -105.0)) -> { longitude = (d - 10.0) * 60.0; "c" }
+        ((d >= 15.0) && (d <= 20.0)) || ((d >= -105.0) && (d <= -100.0)) -> { longitude = (d - 15.0) * 60.0; "d" }
+        ((d >= 20.0) && (d <= 25.0)) || ((d >= -100.0) && (d <= -95.0)) -> { longitude = (d - 20.0) * 60.0; "e" }
+        ((d >= 25.0) && (d <= 30.0)) || ((d >= -95.0) && (d <= -90.0)) -> { longitude = (d - 25.0) * 60.0; "f" }
+        ((d >= 30.0) && (d <= 35.0)) || ((d >= -90.0) && (d <= -85.0)) -> { longitude = (d - 30.0) * 60.0; "g" }
+        ((d >= 35.0) && (d <= 40.0)) || ((d >= -85.0) && (d <= -80.0)) -> { longitude = (d - 35.0) * 60.0; "h" }
+        ((d >= 40.0) && (d <= 45.0)) || ((d >= -80.0) && (d <= -75.0)) -> { longitude = (d - 40.0) * 60.0; "i" }
+        ((d >= 45.0) && (d <= 50.0)) || ((d >= -75.0) && (d <= -70.0)) -> { longitude = (d - 45.0) * 60.0; "j" }
+        ((d >= 50.0) && (d <= 55.0)) || ((d >= -70.0) && (d <= -65.0)) -> { longitude = (d - 50.0) * 60.0; "k" }
+        ((d >= 55.0) && (d <= 60.0)) || ((d >= -65.0) && (d <= -60.0)) -> { longitude = (d - 55.0) * 60.0; "l" }
+        ((d >= 60.0) && (d <= 65.0)) || ((d >= -60.0) && (d <= -55.0)) -> { longitude = (d - 60.0) * 60.0; "m" }
+        ((d >= 65.0) && (d <= 70.0)) || ((d >= -55.0) && (d <= -50.0)) -> { longitude = (d - 65.0) * 60.0; "n" }
+        ((d >= 70.0) && (d <= 75.0)) || ((d >= -50.0) && (d <= -45.0)) -> { longitude = (d - 70.0) * 60.0; "o" }
+        ((d >= 75.0) && (d <= 80.0)) || ((d >= -45.0) && (d <= -40.0)) -> { longitude = (d - 75.0) * 60.0; "p" }
+        ((d >= 80.0) && (d <= 85.0)) || ((d >= -40.0) && (d <= -35.0)) -> { longitude = (d - 80.0) * 60.0; "q" }
+        ((d >= 85.0) && (d <= 90.0)) || ((d >= -35.0) && (d <= -30.0)) -> { longitude = (d - 85.0) * 60.0; "r" }
+        ((d >= 90.0) && (d <= 95.0)) || ((d >= -30.0) && (d <= -25.0)) -> { longitude = (d - 90.0) * 60.0; "s" }
+        ((d >= 95.0) && (d <= 100.0)) || ((d >= -25.0) && (d <= -20.0)) -> { longitude = (d - 95.0) * 60.0; "t" }
+        ((d >= 100.0) && (d <= 105.0)) || ((d >= -20.0) && (d <= -15.0)) -> { longitude = (d - 100.0) * 60.0; "u" }
+        ((d >= 105.0) && (d <= 110.0)) || ((d >= -15.0) && (d <= -10.0)) -> { longitude = (d - 105.0) * 60.0; "v" }
+        ((d >= 110.0) && (d <= 115.0)) || ((d >= -10.0) && (d <= -5.0)) -> { longitude = (d - 110.0) * 60.0; "w" }
+        ((d >= 115.0) && (d <= 120.0)) || ((d >= -5.0) && (d <= 0.0)) -> { longitude = (d - 115.0) * 60.0; "x" }
+        else -> { longitude = 0.0; " " }
     }
+    val str4 = when {
+        ((longitude >= 0.0) && (longitude <= 30.0)) || ((longitude >= -300.0) && (longitude <= -270.0)) -> "0"
+        ((longitude >= 30.0) && (longitude <= 60.0)) || ((longitude >= -270.0) && (longitude <= -240.0)) -> "1"
+        ((longitude >= 60.0) && (longitude <= 90.0)) || ((longitude >= -240.0) && (longitude <= -210.0)) -> "2"
+        ((longitude >= 90.0) && (longitude <= 120.0)) || ((longitude >= -210.0) && (longitude <= -180.0)) -> "3"
+        ((longitude >= 120.0) && (longitude <= 150.0)) || ((longitude >= -180.0) && (longitude <= -150.0)) -> "4"
+        ((longitude >= 150.0) && (longitude <= 180.0)) || ((longitude >= -150.0) && (longitude <= -120.0)) -> "5"
+        ((longitude >= 180.0) && (longitude <= 210.0)) || ((longitude >= -120.0) && (longitude <= -90.0)) -> "6"
+        ((longitude >= 210.0) && (longitude <= 240.0)) || ((longitude >= -90.0) && (longitude <= -60.0)) -> "7"
+        ((longitude >= 240.0) && (longitude <= 270.0)) || ((longitude >= -60.0) && (longitude <= -30.0)) -> "8"
+        ((longitude >= 270.0) && (longitude <= 300.0)) || ((longitude >= -30.0) && (longitude <= 0.0)) -> "9"
+        else -> " "
+    }
+    return listOf(str, str2, str3, str4)
 }
 
-private fun formatDms(value: Double, isLat: Boolean): String {
-    val abs = kotlin.math.abs(value)
-    val deg = abs.toInt()
-    val minFull = (abs - deg) * 60
-    val min = minFull.toInt()
-    val sec = ((minFull - min) * 60).toInt()
-    val hemi = if (value >= 0) (if (isLat) "N" else "E") else (if (isLat) "S" else "W")
-    return "$deg° $min' $sec\" $hemi"
+// 照搬 612-914 行: 纬度 -> (10°区字母, 1°数字, 1'字母, 15"数字)
+private fun encodeLat(inputLat: Double): List<String> {
+    var latitude = inputLat
+    var d2 = 0.0
+    var d3 = 0.0
+    val str5 = when {
+        (latitude >= -90.0) && (latitude <= -80.0) -> { d2 = latitude + 90.0; "A" }
+        (latitude >= -80.0) && (latitude <= -70.0) -> { d2 = latitude + 80.0; "B" }
+        (latitude >= -70.0) && (latitude <= -60.0) -> { d2 = latitude + 70.0; "C" }
+        (latitude >= -60.0) && (latitude <= -50.0) -> { d2 = latitude + 60.0; "D" }
+        (latitude >= -50.0) && (latitude <= -40.0) -> { d2 = latitude + 50.0; "E" }
+        (latitude >= -40.0) && (latitude <= -30.0) -> { d2 = latitude + 40.0; "F" }
+        (latitude >= -30.0) && (latitude <= -20.0) -> { d2 = latitude + 30.0; "G" }
+        (latitude >= -20.0) && (latitude <= -10.0) -> { d2 = latitude + 20.0; "H" }
+        (latitude >= -10.0) && (latitude <= 0.0) -> { d2 = latitude + 10.0; "I" }
+        (latitude >= 0.0) && (latitude <= 10.0) -> { d2 = latitude; "J" }
+        (latitude >= 10.0) && (latitude <= 20.0) -> { d2 = latitude - 10.0; "K" }
+        (latitude >= 20.0) && (latitude <= 30.0) -> { d2 = latitude - 20.0; "L" }
+        (latitude >= 30.0) && (latitude <= 40.0) -> { d2 = latitude - 30.0; "M" }
+        (latitude >= 40.0) && (latitude <= 50.0) -> { d2 = latitude - 40.0; "N" }
+        (latitude >= 50.0) && (latitude <= 60.0) -> { d2 = latitude - 50.0; "O" }
+        (latitude >= 60.0) && (latitude <= 70.0) -> { d2 = latitude - 60.0; "P" }
+        (latitude >= 70.0) && (latitude <= 80.0) -> { d2 = latitude - 70.0; "Q" }
+        (latitude >= 80.0) && (latitude <= 90.0) -> { d2 = latitude - 80.0; "R" }
+        else -> { d2 = 0.0; " " }
+    }
+    var str6 = " "
+    when {
+        ((d2 >= 0.0) && (d2 <= 1.0)) || ((d2 >= -10.0) && (d2 <= -9.0)) -> { d3 = d2 * 60.0; str6 = "0" }
+        ((d2 >= 1.0) && (d2 <= 2.0)) || ((d2 >= -9.0) && (d2 <= -8.0)) -> { d3 = (d2 - 1.0) * 60.0; str6 = "1" }
+        ((d2 >= 2.0) && (d2 <= 3.0)) || ((d2 >= -8.0) && (d2 <= -7.0)) -> { d3 = (d2 - 2.0) * 60.0; str6 = "2" }
+        ((d2 >= 3.0) && (d2 <= 4.0)) || ((d2 >= -7.0) && (d2 <= -6.0)) -> { d3 = (d2 - 3.0) * 60.0; str6 = "3" }
+        ((d2 >= 4.0) && (d2 <= 5.0)) || ((d2 >= -6.0) && (d2 <= -5.0)) -> { d3 = (d2 - 4.0) * 60.0; str6 = "4" }
+        ((d2 >= 5.0) && (d2 <= 6.0)) || ((d2 >= -5.0) && (d2 <= -4.0)) -> { d3 = (d2 - 5.0) * 60.0; str6 = "5" }
+        ((d2 >= 6.0) && (d2 <= 7.0)) || ((d2 >= -4.0) && (d2 <= -3.0)) -> { d3 = (d2 - 6.0) * 60.0; str6 = "6" }
+        ((d2 >= 7.0) && (d2 <= 8.0)) || ((d2 >= -3.0) && (d2 <= -2.0)) -> { d3 = (d2 - 7.0) * 60.0; str6 = "7" }
+        ((d2 >= 8.0) && (d2 <= 9.0)) || ((d2 >= -2.0) && (d2 <= -1.0)) -> { d3 = (d2 - 8.0) * 60.0; str6 = "8" }
+        ((d2 >= 9.0) && (d2 <= 10.0)) || ((d2 >= -1.0) && (d2 <= 0.0)) -> { d3 = (d2 - 9.0) * 60.0; str6 = "9" }
+    }
+    val str38 = when {
+        ((d3 >= 0.0) && (d3 <= 2.5)) || ((d3 >= -60.0) && (d3 <= -57.5)) -> { d2 = d3 * 60.0; "a" }
+        ((d3 >= 2.5) && (d3 <= 5.0)) || ((d3 >= -57.5) && (d3 <= -55.0)) -> { d2 = (d3 - 2.5) * 60.0; "b" }
+        ((d3 >= 5.0) && (d3 <= 7.5)) || ((d3 >= -55.0) && (d3 <= -52.5)) -> { d2 = (d3 - 5.0) * 60.0; "c" }
+        ((d3 >= 7.5) && (d3 <= 10.0)) || ((d3 >= -52.5) && (d3 <= -50.0)) -> { d2 = (d3 - 7.5) * 60.0; "d" }
+        ((d3 >= 10.0) && (d3 <= 12.5)) || ((d3 >= -50.0) && (d3 <= -47.5)) -> { d2 = (d3 - 10.0) * 60.0; "e" }
+        ((d3 >= 12.5) && (d3 <= 15.0)) || ((d3 >= -47.5) && (d3 <= -45.0)) -> { d2 = (d3 - 12.5) * 60.0; "f" }
+        ((d3 >= 15.0) && (d3 <= 17.5)) || ((d3 >= -45.0) && (d3 <= -42.5)) -> { d2 = (d3 - 15.0) * 60.0; "g" }
+        ((d3 >= 17.5) && (d3 <= 20.0)) || ((d3 >= -42.5) && (d3 <= -40.0)) -> { d2 = (d3 - 17.5) * 60.0; "h" }
+        ((d3 >= 20.0) && (d3 <= 22.5)) || ((d3 >= -40.0) && (d3 <= -37.5)) -> { d2 = (d3 - 20.0) * 60.0; "i" }
+        ((d3 >= 22.5) && (d3 <= 25.0)) || ((d3 >= -37.5) && (d3 <= -35.0)) -> { d2 = (d3 - 22.5) * 60.0; "j" }
+        ((d3 >= 25.0) && (d3 <= 27.5)) || ((d3 >= -35.0) && (d3 <= -32.5)) -> { d2 = (d3 - 25.0) * 60.0; "k" }
+        ((d3 >= 27.5) && (d3 <= 30.0)) || ((d3 >= -32.5) && (d3 <= -30.0)) -> { d2 = (d3 - 27.5) * 60.0; "l" }
+        ((d3 >= 30.0) && (d3 <= 32.5)) || ((d3 >= -30.0) && (d3 <= -27.5)) -> { d2 = (d3 - 30.0) * 60.0; "m" }
+        ((d3 >= 32.5) && (d3 <= 35.0)) || ((d3 >= -27.5) && (d3 <= -25.0)) -> { d2 = (d3 - 32.5) * 60.0; "n" }
+        ((d3 >= 35.0) && (d3 <= 37.5)) || ((d3 >= -25.0) && (d3 <= -22.5)) -> { d2 = (d3 - 35.0) * 60.0; "o" }
+        ((d3 >= 37.5) && (d3 <= 40.0)) || ((d3 >= -22.5) && (d3 <= -20.0)) -> { d2 = (d3 - 37.5) * 60.0; "p" }
+        ((d3 >= 40.0) && (d3 <= 42.5)) || ((d3 >= -20.0) && (d3 <= -17.5)) -> { d2 = (d3 - 40.0) * 60.0; "q" }
+        ((d3 >= 42.5) && (d3 <= 45.0)) || ((d3 >= -17.5) && (d3 <= -15.0)) -> { d2 = (d3 - 42.5) * 60.0; "r" }
+        ((d3 >= 45.0) && (d3 <= 47.5)) || ((d3 >= -15.0) && (d3 <= -12.5)) -> { d2 = (d3 - 45.0) * 60.0; "s" }
+        ((d3 >= 47.5) && (d3 <= 50.0)) || ((d3 >= -12.5) && (d3 <= -10.0)) -> { d2 = (d3 - 47.5) * 60.0; "t" }
+        ((d3 >= 50.0) && (d3 <= 52.5)) || ((d3 >= -10.0) && (d3 <= -7.5)) -> { d2 = (d3 - 50.0) * 60.0; "u" }
+        ((d3 >= 52.5) && (d3 <= 55.0)) || ((d3 >= -7.5) && (d3 <= -5.0)) -> { d2 = (d3 - 52.5) * 60.0; "v" }
+        ((d3 >= 55.0) && (d3 <= 57.5)) || ((d3 >= -5.0) && (d3 <= -2.5)) -> { d2 = (d3 - 55.0) * 60.0; "w" }
+        ((d3 >= 57.5) && (d3 <= 60.0)) || ((d3 >= -2.5) && (d3 <= 0.0)) -> { d2 = (d3 - 57.5) * 60.0; "x" }
+        else -> { d2 = 0.0; " " }
+    }
+    val str9 = when {
+        ((d2 >= 0.0) && (d2 <= 15.0)) || ((d2 >= -150.0) && (d2 <= -135.0)) -> "0"
+        ((d2 >= 15.0) && (d2 <= 30.0)) || ((d2 >= -135.0) && (d2 <= -120.0)) -> "1"
+        ((d2 >= 30.0) && (d2 <= 45.0)) || ((d2 >= -120.0) && (d2 <= -105.0)) -> "2"
+        ((d2 >= 45.0) && (d2 <= 60.0)) || ((d2 >= -105.0) && (d2 <= -90.0)) -> "3"
+        ((d2 >= 60.0) && (d2 <= 75.0)) || ((d2 >= -90.0) && (d2 <= -75.0)) -> "4"
+        ((d2 >= 75.0) && (d2 <= 90.0)) || ((d2 >= -75.0) && (d2 <= -60.0)) -> "5"
+        ((d2 >= 90.0) && (d2 <= 105.0)) || ((d2 >= -60.0) && (d2 <= -45.0)) -> "6"
+        ((d2 >= 105.0) && (d2 <= 120.0)) || ((d2 >= -45.0) && (d2 <= -30.0)) -> "7"
+        ((d2 >= 120.0) && (d2 <= 135.0)) || ((d2 >= -30.0) && (d2 <= -15.0)) -> "8"
+        ((d2 >= 135.0) && (d2 <= 150.0)) || ((d2 >= -15.0) && (d2 <= 0.0)) -> "9"
+        else -> " "
+    }
+    return listOf(str5, str6, str38, str9)
 }
 
-private fun formatDecimal(value: Double): String = String.format("%.5f", value)
+/**
+ * 照搬 917-1283 行: 九宫格 parseInt3 五分支(内部/西界/东界/北界/南界 + 四角)。
+ * 返回 9 格文本: [上左, 上中, 上右, 左中, 中央, 右中, 下左, 下中, 下右]。
+ */
+private fun buildGrids(str: String, str5: String, str2: String, str6: String, str3: String, str38: String): List<String> {
+    val parseInt = str2.toInt()
+    val parseInt2 = str6.toInt()
+    val str39 = str + str5
+    val str40 = str2 + str6
+    val parseInt3 = str40.toInt()
+    val str41 = str39 + str40
+    val g = MutableList(9) { "" }
+    fun fmt2(n: Int) = if (n <= 9) "0$n" else n.toString()
+    if ((parseInt > 0) && (parseInt < 9) && (parseInt2 > 0) && (parseInt2 < 9)) {
+        // 内部: 数字对 ±1
+        val i7 = parseInt3 + 1
+        val i8 = i7 - 10
+        val valueOf9 = fmt2(i8)
+        val str11 = i7.toString()
+        val valueOf18 = (i7 + 10).toString()
+        val i9 = parseInt3 - 10
+        val valueOf10 = fmt2(i9)
+        val valueOf19 = (parseInt3 + 10).toString()
+        val i10 = parseInt3 - 1
+        val i11 = i10 - 10
+        val valueOf11 = fmt2(i11)
+        val str14 = i10.toString()
+        val str15 = (i10 + 10).toString()
+        g[0] = str39 + valueOf9
+        g[1] = str39 + str11
+        g[2] = str39 + valueOf18
+        g[3] = str39 + valueOf10
+        g[4] = str41
+        g[5] = str39 + valueOf19
+        g[6] = str39 + valueOf11
+        g[7] = str39 + str14
+        g[8] = str39 + str15
+    } else if ((parseInt == 0) && (parseInt2 > 0) && (parseInt2 < 9)) {
+        // 西边界: 经度 0 -> 9, 经度字母 -1
+        val str43 = (str[0] - 1).toString() + str5
+        val str44 = "9" + (parseInt2 + 1)
+        val i12 = parseInt3 + 1
+        val valueOf7 = fmt2(i12)
+        val str12 = (i12 + 10).toString()
+        val sb4 = "9" + parseInt2
+        val valueOf20 = (parseInt3 + 10).toString()
+        val str46 = "9" + (parseInt2 - 1)
+        val i13 = parseInt3 - 1
+        val valueOf8 = fmt2(i13)
+        val str15 = (i13 + 10).toString()
+        g[0] = str43 + str44
+        g[1] = str39 + valueOf7
+        g[2] = str39 + str12
+        g[3] = str43 + sb4
+        g[4] = str41
+        g[5] = str39 + valueOf20
+        g[6] = str43 + str46
+        g[7] = str39 + valueOf8
+        g[8] = str39 + str15
+    } else if ((parseInt == 9) && (parseInt2 > 0) && (parseInt2 < 9)) {
+        // 东边界: 经度 9 -> 0, 经度字母 +1
+        val str47 = (str[0] + 1).toString() + str5
+        val i14 = parseInt3 + 1
+        val valueOf21 = (i14 - 10).toString()
+        val valueOf22 = i14.toString()
+        val str48 = "0" + (parseInt2 + 1)
+        val valueOf23 = (parseInt3 - 10).toString()
+        val str49 = "0" + parseInt2
+        val i15 = parseInt3 - 1
+        val valueOf24 = (i15 - 10).toString()
+        val valueOf25 = i15.toString()
+        val str15 = "0" + (parseInt2 - 1)
+        g[0] = str39 + valueOf21
+        g[1] = str39 + valueOf22
+        g[2] = str47 + str48
+        g[3] = str39 + valueOf23
+        g[4] = str41
+        g[5] = str47 + str49
+        g[6] = str39 + valueOf24
+        g[7] = str39 + valueOf25
+        g[8] = str47 + str15
+    } else if ((parseInt < 9) && (parseInt > 0) && (parseInt2 == 9)) {
+        // 北边界: 纬度 9 -> 0, 纬度字母 +1
+        val str50 = str + (str5[0] + 1).toString()
+        val i16 = parseInt3 - 9
+        val i17 = i16 - 10
+        val valueOf4 = fmt2(i17)
+        val valueOf26 = i16.toString()
+        val valueOf27 = (i16 + 10).toString()
+        val i18 = parseInt3 - 10
+        val valueOf5 = fmt2(i18)
+        val valueOf28 = (parseInt3 + 10).toString()
+        val i19 = parseInt3 - 1
+        val i20 = i19 - 10
+        val valueOf6 = fmt2(i20)
+        val str14 = i19.toString()
+        val str15 = (i19 + 10).toString()
+        g[0] = str39 + valueOf4
+        g[1] = str50 + valueOf26
+        g[2] = str39 + valueOf27
+        g[3] = str39 + valueOf5
+        g[4] = str41
+        g[5] = str39 + valueOf28
+        g[6] = str39 + valueOf6
+        g[7] = str39 + str14
+        g[8] = str39 + str15
+    } else if ((parseInt < 9) && (parseInt > 0) && (parseInt2 == 0)) {
+        // 南边界: 纬度 0 -> 9, 纬度字母 -1
+        val str52 = str + (str5[0] - 1).toString()
+        val i21 = parseInt3 + 1
+        val i22 = i21 - 10
+        val valueOf = fmt2(i22)
+        val valueOf29 = i21.toString()
+        val valueOf30 = (i21 + 10).toString()
+        val i23 = parseInt3 - 10
+        val valueOf2 = fmt2(i23)
+        val valueOf31 = (parseInt3 + 10).toString()
+        val i24 = parseInt3 - 1
+        val valueOf3 = fmt2(i24)
+        val str14 = (i24 + 10).toString()
+        val str15 = (i24 + 20).toString()
+        g[0] = str39 + valueOf
+        g[1] = str39 + valueOf29
+        g[2] = str39 + valueOf30
+        g[3] = str39 + valueOf2
+        g[4] = str41
+        g[5] = str39 + valueOf31
+        g[6] = str52 + valueOf3
+        g[7] = str52 + str14
+        g[8] = str52 + str15
+    } else if (parseInt3 == 0) {
+        // 四角 00: 经纬度数字均 -1 进位
+        val v32 = (str[0] - 1).toString()
+        val v33 = (str5[0] - 1).toString()
+        g[0] = v32 + str5 + "91"
+        g[1] = str39 + "01"
+        g[2] = str39 + "11"
+        g[3] = v32 + str5 + "90"
+        g[4] = str41
+        g[5] = v32 + str5 + "10"
+        g[6] = v32 + v33 + "99"
+        g[7] = str + v33 + "09"
+        g[8] = str + v33 + "19"
+    } else if (parseInt3 == 9) {
+        // 四角 09: 经度 -1, 纬度 +1
+        val v34 = (str[0] - 1).toString()
+        val v35 = (str5[0] + 1).toString()
+        g[0] = v34 + v35 + "90"
+        g[1] = str + v35 + "00"
+        g[2] = str + v35 + "10"
+        g[3] = v34 + str5 + "99"
+        g[4] = str41
+        g[5] = v34 + str5 + "19"
+        g[6] = v34 + str5 + "98"
+        g[7] = v34 + str5 + "08"
+        g[8] = v34 + str5 + "18"
+    } else if (parseInt3 == 99) {
+        // 四角 99: 经纬度数字均 +1 进位
+        val v36 = (str[0] + 1).toString()
+        val v37 = (str5[0] + 1).toString()
+        g[0] = str + v37 + "80"
+        g[1] = str + v37 + "90"
+        g[2] = v36 + v37 + "00"
+        g[3] = str39 + "89"
+        g[4] = str41
+        g[5] = v36 + str5 + "09"
+        g[6] = str39 + "88"
+        g[7] = str39 + "98"
+        g[8] = v36 + str5 + "08"
+    } else if (parseInt3 == 90) {
+        // 四角 90: 经度 +1, 纬度 -1
+        val v38 = (str[0] + 1).toString()
+        val v39 = (str5[0] - 1).toString()
+        g[0] = str39 + "81"
+        g[1] = str39 + "91"
+        g[2] = v38 + str5 + "01"
+        g[3] = str39 + "80"
+        g[4] = str41
+        g[5] = v38 + str5 + "00"
+        g[6] = str + v39 + "89"
+        g[7] = str + v39 + "99"
+        g[8] = v38 + v39 + "09"
+    }
+    return g
+}
diff --git a/feature/roaming/src/main/java/com/rtbishop/look4sat/feature/roaming/RoamingState.kt b/feature/roaming/src/main/java/com/rtbishop/look4sat/feature/roaming/RoamingState.kt
deleted file mode 100644
index 0cc9de81..00000000
--- a/feature/roaming/src/main/java/com/rtbishop/look4sat/feature/roaming/RoamingState.kt
+++ /dev/null
@@ -1,78 +0,0 @@
-/*
- * Look4Sat. Amateur radio satellite tracker and pass predictor.
- * Copyright (C) 2019-2026 Arty Bishop and contributors.
- *
- * This program is free software: you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation, either version 3 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program.  If not, see <https://www.gnu.org/licenses/>.
- */
-package com.rtbishop.look4sat.feature.roaming
-
-import com.rtbishop.look4sat.core.domain.predict.GeoPos
-import com.rtbishop.look4sat.core.domain.utility.positionToQth
-import com.rtbishop.look4sat.core.domain.utility.qthNeighbors
-import com.rtbishop.look4sat.core.domain.utility.qthToSquare
-
-data class RoamingState(
-    val latitude: Double = 0.0,
-    val longitude: Double = 0.0,
-    val qthLocator: String = "----",
-    val gridSquares: List<String> = List(9) { "----" },
-    /** Fractional position of the red marker inside the center cell, 0..1. */
-    val markerX: Float = 0.5f,
-    val markerY: Float = 0.5f,
-    /** True when a fresh GPS fix is available (station position updated recently). */
-    val gpsEnabled: Boolean = false
-) {
-    companion object {
-        /**
-         * Builds the state from a [GeoPos]. The 3x3 grid and the marker
-         * position are derived from the 8-char locator exactly like the
-         * QTH定位器 app: the marker is placed by the 3rd character pair
-         * (e.g. the "ih" in "OL42ih45"), mapped to a 0..1 fraction.
-         */
-        fun fromPosition(pos: GeoPos): RoamingState {
-            val locator = positionToQth(pos.latitude, pos.longitude) ?: return RoamingState()
-            val square = qthToSquare(locator)
-            val squares = if (square != "----") qthNeighbors(square) else List(9) { "----" }
-            // GPS is simply whatever the station position says — a real fix
-            // (non-zero, with timestamp) counts as enabled.
-            val hasFix = pos.timestamp > 0L && (pos.latitude != 0.0 || pos.longitude != 0.0)
-            return RoamingState(
-                latitude = pos.latitude,
-                longitude = pos.longitude,
-                qthLocator = locator,
-                gridSquares = squares,
-                markerX = markerFraction(locator, isLat = false),
-                markerY = markerFraction(locator, isLat = true),
-                gpsEnabled = hasFix
-            )
-        }
-
-        /**
-         * Fractional position of the fix inside the 4-char square, derived from
-         * the 3rd character pair of an 8-char locator (e.g. the "ih" in
-         * "OL42ih45"). Ported from the QTH定位器 app: it maps the 3rd-pair
-         * letters (a..x) to a position inside the center cell instead of
-         * recomputing from coordinates.
-         * X: a = west edge .. x = east edge (left -> right). Y: a = south ..
-         * x = north, inverted so the value grows downward on screen, matching
-         * the reference app.
-         */
-        private fun markerFraction(locator: String, isLat: Boolean): Float {
-            if (locator.length < 6) return 0.5f
-            val index = if (isLat) locator[5] else locator[4]
-            val fraction = (index.lowercaseChar().code - 97).coerceIn(0, 23) / 24f
-            return if (isLat) 1f - fraction else fraction
-        }
-    }
-}
diff --git a/feature/roaming/src/main/res/drawable/roam_gps_green.png b/feature/roaming/src/main/res/drawable/roam_gps_green.png
new file mode 100644
index 00000000..2202aac6
Binary files /dev/null and b/feature/roaming/src/main/res/drawable/roam_gps_green.png differ
diff --git a/feature/roaming/src/main/res/drawable/roam_gps_red.png b/feature/roaming/src/main/res/drawable/roam_gps_red.png
new file mode 100644
index 00000000..c0af314f
Binary files /dev/null and b/feature/roaming/src/main/res/drawable/roam_gps_red.png differ
diff --git a/feature/roaming/src/main/res/drawable/roam_pnt.png b/feature/roaming/src/main/res/drawable/roam_pnt.png
new file mode 100644
index 00000000..8a1ef8bc
Binary files /dev/null and b/feature/roaming/src/main/res/drawable/roam_pnt.png differ
diff --git a/feature/roaming/src/test/java/com/rtbishop/look4sat/feature/roaming/RoamingStateTest.kt b/feature/roaming/src/test/java/com/rtbishop/look4sat/feature/roaming/RoamingStateTest.kt
new file mode 100644
index 00000000..1297fda8
--- /dev/null
+++ b/feature/roaming/src/test/java/com/rtbishop/look4sat/feature/roaming/RoamingStateTest.kt
@@ -0,0 +1,124 @@
+/*
+ * Look4Sat. Amateur radio satellite tracker and pass predictor.
+ * Copyright (C) 2019-2026 Arty Bishop and contributors.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+package com.rtbishop.look4sat.feature.roaming
+
+import org.junit.Assert.assertEquals
+import org.junit.Test
+
+class RoamingStateTest {
+
+    // 用户实测坐标 (QTH定位器 2.0 成品截图): 22.314066 / 108.706575
+    private fun stateOf(lat: Double, lon: Double) =
+        roamingStateFromLocation(lat, lon, System.currentTimeMillis(), "21:")
+
+    @Test
+    fun `user coordinates produce OL42ih45`() {
+        val state = stateOf(22.314066, 108.706575)
+        assertEquals("OL42ih45", state.loc)
+    }
+
+    @Test
+    fun `red marker from ih pair matches reference lookup`() {
+        val state = stateOf(22.314066, 108.706575)
+        // 成品查表: 经度第3对 'i' -> leftMargin 65dp, 纬度第3对 'h' -> topMargin 137dp
+        assertEquals(65, state.markerLeft)
+        assertEquals(137, state.markerTop)
+    }
+
+    @Test
+    fun `grid nine from OL42 matches reference`() {
+        val state = stateOf(22.314066, 108.706575)
+        val expected = listOf(
+            "OL33", "OL43", "OL53",
+            "OL32", "OL42", "OL52",
+            "OL31", "OL41", "OL51"
+        )
+        assertEquals(expected, state.grids)
+    }
+
+    @Test
+    fun `latitude dms formatting matches reference`() {
+        val state = stateOf(22.314066, 108.706575)
+        assertEquals("纬度  22° 18' 50\" N", state.latLabel)
+        assertEquals("22.314066° ", state.latValue)
+        assertEquals("经度 108° 42' 23\" E", state.lonLabel)
+        assertEquals("108.706575° ", state.lonValue)
+    }
+
+    @Test
+    fun `time is hour prefix plus fix minutes`() {
+        // fixTime = 2026-08-03 21:12:13 UTC+8 -> minutes 12
+        val fix = 1785820333000L // 2026-08-03 21:12:13 +0800
+        val state = roamingStateFromLocation(22.314066, 108.706575, fix, "21:")
+        assertEquals("21:12", state.time)
+    }
+
+    @Test
+    fun `west edge borrows lon letter`() {
+        // 经度 0.5 纬度 22.314066: 数字对 02, 西边界 parseInt==0
+        val state = stateOf(22.314066, 0.5)
+        assertEquals(8, state.loc.length)
+        // 左列经度 0->9, 经度字母 J-1=I: IL92
+        assertEquals("IL92", state.grids[3])
+    }
+
+    @Test
+    fun `north edge carries lat letter`() {
+        // 纬度 29.5 经度 108.706575: 数字对 49? -> 纬度数字 9 -> 北边界
+        val state = stateOf(29.5, 108.706575)
+        assertEquals(8, state.loc.length)
+        // 上排纬度 +1 -> 0, 纬度字母 +1 (M)
+        assertEquals("OM40", state.grids[1])
+    }
+
+    @Test
+    fun `east edge carries lon letter`() {
+        // 经度 119.5 纬度 22.314066: 经度数字 9 -> 东边界
+        val state = stateOf(22.314066, 119.5)
+        assertEquals(8, state.loc.length)
+        // 右上 经度 9->0, 经度字母 O+1=P, 纬度 2+1=3: PL03
+        assertEquals("PL03", state.grids[2])
+    }
+
+    @Test
+    fun `south edge borrows lat letter`() {
+        // 纬度 0.5 经度 108.706575: 纬度数字 0 -> 南边界
+        val state = stateOf(0.5, 108.706575)
+        assertEquals(8, state.loc.length)
+        // 下中 纬度 0->9, 纬度字母 J-1=I: OI49
+        assertEquals("OI49", state.grids[7])
+    }
+
+    @Test
+    fun `boundary values wrap like reference`() {
+        // (90, 180) -> RR99xx99 (成品区间查表行为)
+        val state = stateOf(90.0, 180.0)
+        assertEquals("RR99xx99", state.loc)
+    }
+
+    @Test
+    fun `gps state after fix matches showLocation`() {
+        val state = stateOf(22.314066, 108.706575)
+        assertEquals(true, state.gpsOn)
+        assertEquals(false, state.gpsOff)
+        assertEquals(false, state.showSettings)
+        assertEquals(false, state.showProgress)
+        assertEquals(false, state.showNotice)
+        assertEquals(true, state.showDate)
+    }
+}