diff --git a/map4.js b/map4.js
index 6f4fe95..3dd96c7 100644
--- a/map4.js
+++ b/map4.js
@@ -1,9 +1,11 @@
 // ===================================
 // Supabase 設定
 // ===================================
-const SUPABASE_URL = "https://ogtlmtnjkpsxsqzqlacj.supabase.co";
+const SUPABASE_URL =
+  "https://ogtlmtnjkpsxsqzqlacj.supabase.co";
 const SUPABASE_KEY =
   "eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpc3MiOiJzdXBhYmFzZSIsInJlZiI6Im9ndGxtdG5qa3BzeHNxenFsYWNqIiwicm9sZSI6ImFub24iLCJpYXQiOjE3NjMyOTU3NjUsImV4cCI6MjA3ODg3MTc2NX0.JnCE7oUQwrSgGqiu-QRbwnaLBZrO8JX1_RUb37VIMFI";
+
 const supa = window.supabase.createClient(SUPABASE_URL, SUPABASE_KEY);
 
 // ===================================
@@ -16,9 +18,7 @@
 }
 
 // ===================================
-// 変数
-// ===================================
-let allMembers = []; // ← 一度参加したメンバーは全員ここに保存
+let allMembers = [];
 let currentGroup = "";
 let currentUser = "";
 let map;
@@ -28,19 +28,19 @@
 let lastLat = null;
 let lastLng = null;
 
-let isHost = false; // ← Supabase で判定する本物のホスト判定
+let isHost = false;
 
 // 駅関連
 let stationMarkers = [];
 
-// 目的地共有関連
+// 目的地関連
 let targetMarker = null;
 let targetLat = null;
 let targetLng = null;
 let arrived = false;
 let lastShownDistance = null;
 
-// デフォルト（皇居）
+// 皇居
 const DEFAULT_LAT = 35.681236;
 const DEFAULT_LNG = 139.767125;
 
@@ -66,8 +66,6 @@
 });
 
 // ===================================
-// URL のグループ / ユーザー読み込み
-// ===================================
 function loadParams() {
   const p = new URLSearchParams(location.search);
   currentGroup = p.get("group");
@@ -77,33 +75,21 @@
 }
 
 // ===================================
-// 本物のホスト判定（Supabase groups.host_name）
-// ===================================
 async function decideHost() {
-  const { data, error } = await supa
+  const { data } = await supa
     .from("groups")
     .select("host_name")
     .eq("group_name", currentGroup)
     .maybeSingle();
 
-  if (error) {
-    console.error("ホスト情報の取得に失敗:", error);
-    isHost = false;
-  } else if (data && data.host_name) {
-    isHost = data.host_name === currentUser;
-  } else {
-    isHost = false;
-  }
+  isHost = data?.host_name === currentUser;
 
-  // 画面表示へ反映
   const hostLabel = document.getElementById("hostStatus");
-  if (hostLabel)
-    hostLabel.textContent = isHost ? "あなたはホストです" : "一般メンバーです";
+  hostLabel.textContent =
+    isHost ? "あなたはホストです" : "一般メンバーです";
 }
 
 // ===================================
-// 小型ピン
-// ===================================
 function createLabeledMarker(lat, lng, name, isSelf) {
   const pinUrl = isSelf
     ? "https://raw.githubusercontent.com/pointhi/leaflet-color-markers/master/img/marker-icon-green.png"
@@ -132,69 +118,45 @@
     navigator.geolocation.getCurrentPosition(
       (pos) => res(pos.coords),
       rej,
-      {
-        enableHighAccuracy: true,
-      }
+      { enableHighAccuracy: true }
     );
   });
 }
 
 // ===================================
-// マップ初期化（正しい構造版）
-// ===================================
 function initMap(lat, lng) {
   map = L.map("map").setView([lat, lng], 16);
 
-  L.tileLayer("https://tile.openstreetmap.org/{z}/{x}/{y}.png", {
-    maxZoom: 19,
-  }).addTo(map);
+  L.tileLayer(
+    "https://tile.openstreetmap.org/{z}/{x}/{y}.png",
+    { maxZoom: 19 }
+  ).addTo(map);
 
-  // ★目的地設定（ホストのみ）
+  // ホストだけ目的地設定
   map.on("click", async (e) => {
-    if (!isHost) {
-      alert("目的地を設定できるのはホストだけです！");
-      return;
-    }
+    if (!isHost) return;
 
-    const newLat = e.latlng.lat;
-    const newLng = e.latlng.lng;
-
-    // すでに目的地がある場合＝再設定確認
-    if (targetLat !== null && targetLng !== null) {
-      const confirmReset = confirm("目的地を再設定しますか？");
-      if (!confirmReset) return;
-    }
-
-    // ▼到着通知の初期化
-    arrived = false;
-    lastShownDistance = null;
-
-    const box = document.getElementById("targetInfo");
-    box.style.background = "";
-    box.style.borderLeft = "";
-    box.textContent = "目的地を設定中…";
-
-    // ▼目的地更新
-    targetLat = newLat;
-    targetLng = newLng;
+    targetLat = e.latlng.lat;
+    targetLng = e.latlng.lng;
 
     if (targetMarker) map.removeLayer(targetMarker);
-    targetMarker = L.marker([targetLat, targetLng], { icon: targetIcon }).addTo(map);
 
-    // ▼Supabaseへ保存
+    targetMarker = L.marker([targetLat, targetLng], {
+      icon: targetIcon,
+    }).addTo(map);
+
     await supa.from("shared_target").upsert({
       group_name: currentGroup,
       lat: targetLat,
-      lng: targetLng
+      lng: targetLng,
     });
 
-    box.textContent = "目的地をグループに共有しました！";
+    document.getElementById("targetInfo").textContent =
+      "目的地を設定しました！";
   });
 }
 
 // ===================================
-// 自分の位置保存
-// ===================================
 async function saveMyLocation(lat, lng) {
   await supa
     .from("locations")
@@ -217,64 +179,48 @@
   selfMarker = createLabeledMarker(lastLat, lastLng, currentUser, true);
   selfMarker.addTo(map);
 }
+
 // ===================================
-// メンバー一覧（永続保持版・チカチカゼロ）
-// ===================================
-function showMemberList(latestByDevice) {
+function showMemberList(latest) {
   const list = document.getElementById("memberList");
 
-  // ① 新しい人を allMembers に追加（順番は固定）
-  Object.values(latestByDevice).forEach(row => {
-    if (!allMembers.some(m => m.device_id === row.device_id)) {
+  Object.values(latest).forEach((row) => {
+    if (!allMembers.some((m) => m.device_id === row.device_id)) {
       allMembers.push({
         device_id: row.device_id,
-        user_name: row.user_name
+        user_name: row.user_name,
       });
     }
   });
 
-  // ② allMembers の順番で表示する（位置が変わらない！）
-  allMembers.forEach(member => {
-    let li = list.querySelector(`li[data-id="${member.device_id}"]`);
-
-    // 初登場なら li を作成
+  allMembers.forEach((m) => {
+    let li = list.querySelector(`li[data-id="${m.device_id}"]`);
     if (!li) {
       li = document.createElement("li");
-      li.dataset.id = member.device_id;
-
+      li.dataset.id = m.device_id;
       li.innerHTML = `
         <div class="member-icon"></div>
         <span class="member-name"></span>
-        <span class="member-status"></span>
-      `;
+        <span class="member-status"></span>`;
       list.appendChild(li);
     }
 
-    // オンライン判定（いない場合はオフライン扱い）
-    const row = latestByDevice[member.device_id];
+    li.querySelector(".member-name").textContent = m.user_name;
+
+    const row = latest[m.device_id];
     const online =
       row &&
       (Date.now() - new Date(row.updated_at)) / 1000 < 6;
 
-    // テキスト更新
-    li.querySelector(".member-name").textContent = member.user_name;
-
-    // 色（自分は緑、他人は黄）
-    const iconColor =
-      member.device_id === deviceId ? "#58c16b" : "#FFD700";
-    li.querySelector(".member-icon").style.background = iconColor;
+    li.querySelector(".member-icon").style.background =
+      m.device_id === deviceId ? "#58c16b" : "#FFD700";
 
     li.querySelector(".member-status").textContent =
       online ? "🟢" : "🔴";
-
-    li.classList.toggle("online", online);
-    li.classList.toggle("offline", !online);
   });
 }
 
 // ===================================
-// 他ユーザー取得
-// ===================================
 async function showOtherUsers() {
   const { data } = await supa
     .from("locations")
@@ -294,89 +240,32 @@
 
   Object.values(latestByDevice).forEach((row) => {
     if (row.device_id === deviceId) return;
-    const mk = createLabeledMarker(row.lat, row.lng, row.user_name, false);
+    const mk = createLabeledMarker(
+      row.lat,
+      row.lng,
+      row.user_name,
+      false
+    );
     mk.addTo(map);
     otherMarkers.push(mk);
   });
 }
 
 // ===================================
-// 距離計算
-// ===================================
-function distanceMeters(lat1, lng1, lat2, lng2) {
+function distanceMeters(a, b, c, d) {
   const R = 6371000;
-  const toRad = (deg) => deg * Math.PI / 180;
-
-  const dLat = toRad(lat2 - lat1);
-  const dLng = toRad(lng2 - lng1);
-
-  const a =
+  const toRad = (x) => (x * Math.PI) / 180;
+  const dLat = toRad(c - a);
+  const dLng = toRad(d - b);
+  const y =
     Math.sin(dLat / 2) ** 2 +
-    Math.cos(toRad(lat1)) *
-    Math.cos(toRad(lat2)) *
-    Math.sin(dLng / 2) ** 2;
-
-  return R * 2 * Math.atan2(Math.sqrt(a), Math.sqrt(1 - a));
+    Math.cos(toRad(a)) *
+      Math.cos(toRad(c)) *
+      Math.sin(dLng / 2) ** 2;
+  return R * 2 * Math.atan2(Math.sqrt(y), Math.sqrt(1 - y));
 }
 
 // ===================================
-// 到着判定（OKボタン付き）
-// ===================================
-function checkArrival() {
-  if (targetLat === null || targetLng === null) return;
-
-  const d = distanceMeters(lastLat, lastLng, targetLat, targetLng);
-  const km = (d / 1000).toFixed(2);
-  const box = document.getElementById("targetInfo");
-
-  // ▼50m以上変わったときだけ更新
-  if (lastShownDistance === null || Math.abs(d - lastShownDistance) > 50) {
-    box.style.background = "";
-    box.style.borderLeft = "";
-    box.innerHTML = `目的地まで 約 ${km} km`;
-    lastShownDistance = d;
-  }
-
-  // ▼到着判定（初回のみ）
-  if (d < 120 && !arrived) {
-    arrived = true;
-
-    box.style.background = "#ffe4e1";
-    box.style.borderLeft = "5px solid #ff4d6d";
-
-    // OK ボタン付き表示
-    box.innerHTML = `
-      🎉 目的地に到着しました！ 🎉<br>
-      <button id="okArrivalBtn" style="
-        margin-top:8px;
-        padding:6px 12px;
-        border-radius:6px;
-        background:#ff6b8c;
-        color:white;
-        border:none;
-        cursor:pointer;
-      ">OK！</button>
-    `;
-
-    // ボタンクリックで状態をリセット
-    setTimeout(() => {
-      const btn = document.getElementById("okArrivalBtn");
-      if (btn) {
-        btn.onclick = () => {
-          arrived = false;
-          lastShownDistance = null;
-          box.style.background = "";
-          box.style.borderLeft = "";
-          box.textContent = "目的地情報を待っています…";
-        };
-      }
-    }, 100);
-  }
-}
-
-// ===================================
-// 駅取得
-// ===================================
 async function fetchStationsAround(lat, lng) {
   const query = `
     [out:json];
@@ -402,7 +291,7 @@
     stationMarkers = [];
 
     if (stations.length === 0) {
-      box.textContent = "駅が見つかりませんでした。";
+      box.textContent = "駅なし";
       return;
     }
 
@@ -410,35 +299,25 @@
     let nearestDist = Infinity;
 
     stations.forEach((st) => {
-      const sLat = st.lat;
-      const sLng = st.lon;
-      const name = st.tags?.name || "駅名不明";
-
-      const d = distanceMeters(lastLat, lastLng, sLat, sLng);
+      const d = distanceMeters(lastLat, lastLng, st.lat, st.lon);
       if (d < nearestDist) {
-        nearest = { name, lat: sLat, lng: sLng };
         nearestDist = d;
+        nearest = st;
       }
-
-      const mk = L.marker([sLat, sLng], { icon: stationIcon }).addTo(map);
-      mk.bindPopup(name + "駅");
+      const mk = L.marker([st.lat, st.lon], {
+        icon: stationIcon,
+      }).addTo(map);
       stationMarkers.push(mk);
     });
 
-    box.textContent =
-      "最寄り駅：" +
-      nearest.name +
-      "（約 " +
-      (nearestDist / 1000).toFixed(2) +
-      " km）";
+    box.textContent = `最寄り駅：${nearest.tags.name}（約 ${(nearestDist /
+      1000).toFixed(2)} km）`;
   } catch {
-    box.textContent = "駅情報を取得できませんでした。";
+    box.textContent = "駅情報エラー";
   }
 }
 
 // ===================================
-// 共有目的地の読込
-// ===================================
 async function loadSharedTarget() {
   const { data } = await supa
     .from("shared_target")
@@ -453,23 +332,21 @@
   targetLat = data.lat;
   targetLng = data.lng;
   arrived = false;
-  lastShownDistance = null;
 
   if (targetMarker) map.removeLayer(targetMarker);
+
   targetMarker = L.marker([targetLat, targetLng], {
     icon: targetIcon,
   }).addTo(map);
 
   document.getElementById("targetInfo").textContent =
-    "目的地が共有されました！距離計算中…";
+    "目的地が共有されました！";
 }
 
 // ===================================
-// main
-// ===================================
 async function main() {
   loadParams();
-  await decideHost(); // ← 本物のホスト判定！
+  await decideHost();
 
   let lat = DEFAULT_LAT;
   let lng = DEFAULT_LNG;
@@ -497,15 +374,13 @@
       const pos = await getPosition();
       lastLat = pos.latitude;
       lastLng = pos.longitude;
-
       renderSelfMarker();
       await saveMyLocation(lastLat, lastLng);
-      checkArrival();
     } catch {}
   }, 2000);
 
-  setInterval(showOtherUsers, 1000);
-  setInterval(loadSharedTarget, 10000); // ← 上書きしない安全な更新
+  setInterval(showOtherUsers, 1200);
+  setInterval(loadSharedTarget, 10000);
 
   document.getElementById("exitBtn").onclick = () => {
     location.href = "index.html";
@@ -516,18 +391,19 @@
 
 window.addEventListener("DOMContentLoaded", main);
 
-// Supabase クライアント
-const supa = window.supabase.createClient(SUPABASE_URL, SUPABASE_KEY);
+// ===================================
+// ★ チャット機能（ここから下だけ追加）
+// ===================================
 
-// ユーザー名（localStorage）
-let userName = localStorage.getItem("userName");
-if (!userName) {
-  userName = prompt("名前を入力してください");
-  localStorage.setItem("userName", userName);
+// ユーザー名
+let chatUser = localStorage.getItem("userName");
+if (!chatUser) {
+  chatUser = prompt("名前を入力してください");
+  localStorage.setItem("userName", chatUser);
 }
 
-// グループ名（すでにあなたのマップに存在する想定）
-const groupName = localStorage.getItem("group");
+// グループ
+const chatGroup = localStorage.getItem("group");
 
 // DOM
 const chatList = document.getElementById("chatList");
@@ -540,25 +416,30 @@
   if (text === "") return;
 
   await supa.from("messages").insert({
-    group_name: groupName,
-    user_name: userName,
-    message: text
+    group_name: chatGroup,
+    user_name: chatUser,
+    message: text,
   });
 
   chatInput.value = "";
 });
 
-// メッセージ取得（2秒ごと）
+// メッセージ取得
 async function loadMessages() {
   const { data } = await supa
     .from("messages")
     .select("*")
-    .eq("group_name", groupName)
+    .eq("group_name", chatGroup)
     .order("created_at", { ascending: true });
 
   chatList.innerHTML = data
-    .map(m => `<div><strong>${m.user_name}:</strong> ${m.message}</div>`)
+    .map(
+      (m) =>
+        `<div><strong>${m.user_name}:</strong> ${m.message}</div>`
+    )
     .join("");
+
+  chatList.scrollTop = chatList.scrollHeight;
 }
 
 setInterval(loadMessages, 2000);