diff --git a/web/display/src/LineStrips.tsx b/web/display/src/LineStrips.tsx
index 7718597..add8ee5 100644
--- a/web/display/src/LineStrips.tsx
+++ b/web/display/src/LineStrips.tsx
@@ -6,9 +6,9 @@ import { useQuery } from '@shared/hooks'
 
 /** 总览卡片可以看的时长，以及每一格的长度（格数约 36～48，太多就挤了）。 */
 export const OVERVIEW_RANGES = [
-  { value: '3h', label: '3 小时', hours: 3, step: '5m', stepMin: 5 },
-  { value: '6h', label: '6 小时', hours: 6, step: '10m', stepMin: 10 },
-  { value: '12h', label: '12 小时', hours: 12, step: '15m', stepMin: 15 },
+  { value: '3h', label: '近 3 小时', hours: 3, step: '5m', stepMin: 5 },
+  { value: '6h', label: '近 6 小时', hours: 6, step: '10m', stepMin: 10 },
+  { value: '12h', label: '近 12 小时', hours: 12, step: '15m', stepMin: 15 },
 ] as const
 
 export type OverviewRange = (typeof OVERVIEW_RANGES)[number]['value']
@@ -68,32 +68,38 @@ export function LineStrips({ lineId, range, m }: Props) {
         <div className="line-mini-quic-head" title={`QUIC RTT p50 ${fmtMs(m['rtt.p50'])} · p95 ${fmtMs(m['rtt.p95'])} · p99 ${fmtMs(m['rtt.p99'])}`}>
           <span>QUIC</span><strong className="num">{fmtMs(m['rtt.p50'])}</strong><small>悬停看 p95 / p99</small>
         </div>
-        <div className="line-mini-direction-row" title={`去程 Probe → Agent 丢包 ${fmtPct(up)}`}>
-          <span>去程</span>
+        <div className="line-mini-direction">
+          <div className="line-mini-direction-head" title={`去程 Probe → Agent 丢包 ${fmtPct(up)}`}>
+            <span>去程</span>
+            <span className={`line-mini-badge ${levelOf(up)}`}>{upText}</span>
+          </div>
           <div className="bars" role="img" aria-label={`近 ${common.hoursText}每 ${common.stepText}的去程丢包`}>
             {(s ? lossUp : Array.from({ length: common.cells }, () => null)).map((value, i) => (
               <span key={`up-${t[i] ?? i}`} className={`bar ${s ? levelOf(value) : 'none'}${hover === i ? ' on' : ''}`} />
             ))}
           </div>
-          <span className={`line-mini-badge ${levelOf(up)}`}>{upText}</span>
         </div>
-        <div className="line-mini-direction-row" title={`回程 Agent → Probe 丢包 ${fmtPct(down)}`}>
-          <span>回程</span>
+        <div className="line-mini-direction">
+          <div className="line-mini-direction-head" title={`回程 Agent → Probe 丢包 ${fmtPct(down)}`}>
+            <span>回程</span>
+            <span className={`line-mini-badge ${levelOf(down)}`}>{downText}</span>
+          </div>
           <div className="bars" role="img" aria-label={`近 ${common.hoursText}每 ${common.stepText}的回程丢包`}>
             {(s ? lossDown : Array.from({ length: common.cells }, () => null)).map((value, i) => (
               <span key={`down-${t[i] ?? i}`} className={`bar ${s ? levelOf(value) : 'none'}${hover === i ? ' on' : ''}`} />
             ))}
           </div>
-          <span className={`line-mini-badge ${levelOf(down)}`}>{downText}</span>
         </div>
-        <div className="line-mini-tcp-row" title={`TCP RTT p50 ${fmtMs(m['tcp.rtt.p50'])}`}>
-          <span>TCP</span><strong className="num">{fmtMs(m['tcp.rtt.p50'])}</strong>
+        <div className="line-mini-tcp">
+          <div className="line-mini-tcp-head" title={`TCP RTT p50 ${fmtMs(m['tcp.rtt.p50'])}`}>
+            <span>TCP</span><strong className="num">{fmtMs(m['tcp.rtt.p50'])}</strong>
+            <span className={`line-mini-badge ${retransTone}`}>{retransText}</span>
+          </div>
           <div className="bars" role="img" aria-label={`近 ${common.hoursText}每 ${common.stepText}的 TCP 重传`}>
             {(s ? retrans : Array.from({ length: common.cells }, () => null)).map((value, i) => (
               <span key={`retrans-${t[i] ?? i}`} className={`bar ${s ? levelOf(value) : 'none'}${hover === i ? ' on' : ''}`} />
             ))}
           </div>
-          <span className={`line-mini-badge ${retransTone}`}>{retransText}</span>
         </div>
       </div>
       <div className={`pop num${hover !== null && at !== null ? ' open' : ''}`} role="tooltip" aria-hidden={hover === null}>
diff --git a/web/display/src/display.css b/web/display/src/display.css
index 037d085..0a0dc76 100644
--- a/web/display/src/display.css
+++ b/web/display/src/display.css
@@ -116,6 +116,29 @@
   margin-top: 8px;
 }
 
+.line-loading-state,
+.line-empty-state {
+  display: flex;
+  min-height: 58px;
+  align-items: center;
+  justify-content: center;
+  gap: 10px;
+  margin-top: 16px;
+  border: 1px solid var(--glass-ring);
+  border-radius: var(--r-card);
+  background: color-mix(in srgb, var(--glass-bg) 75%, transparent);
+  color: var(--app-ink-muted);
+  font-size: 13px;
+}
+
+.line-loading-state .loading-bar {
+  height: 2px;
+}
+
+.line-empty-state {
+  color: var(--app-ink-faint);
+}
+
 .line-page .faint,
 .line-page .chart-hint,
 .line-page .chart-section h2,
@@ -1359,15 +1382,15 @@
 }
 
 .line-mini-quic-head > span,
-.line-mini-direction-row > span:first-child,
-.line-mini-tcp-row > span:first-child {
+.line-mini-direction-head > span:first-child,
+.line-mini-tcp-head > span:first-child {
   color: var(--app-ink-muted);
   font-size: 10px;
   font-weight: 600;
 }
 
 .line-mini-quic-head > strong,
-.line-mini-tcp-row > strong {
+.line-mini-tcp-head > strong {
   color: var(--app-ink);
   font-size: 14px;
   font-weight: 700;
@@ -1381,32 +1404,40 @@
   white-space: nowrap;
 }
 
-.line-mini-direction-row {
+.line-mini-direction,
+.line-mini-tcp {
   display: grid;
-  grid-template-columns: 34px minmax(0, 1fr) 66px;
-  align-items: center;
-  gap: 5px;
+  gap: 3px;
   min-width: 0;
 }
 
-.line-mini-direction-row > span:first-child,
-.line-mini-tcp-row > span:first-child {
+.line-mini-direction-head,
+.line-mini-tcp-head {
+  display: flex;
+  align-items: baseline;
+  gap: 6px;
+  min-width: 0;
+  line-height: 1.25;
+}
+
+.line-mini-direction-head > span:first-child,
+.line-mini-tcp-head > span:first-child {
   font-weight: 500;
   white-space: nowrap;
 }
 
-.line-mini-tcp-row {
-  display: grid;
-  grid-template-columns: 34px 46px minmax(0, 1fr) max-content;
-  align-items: center;
-  gap: 5px;
-  min-width: 0;
+.line-mini-direction-head .line-mini-badge,
+.line-mini-tcp-head .line-mini-badge {
+  margin-left: auto;
+}
+
+.line-mini-tcp {
   margin-top: 2px;
   padding-top: 5px;
   border-top: 1px solid var(--app-outline-soft);
 }
 
-.line-mini-tcp-row > strong {
+.line-mini-tcp-head > strong {
   font-size: 12px;
 }
 
@@ -1693,6 +1724,7 @@
 .agent-head .flag {
   flex: none;
   width: 24px;
+  max-width: 24px;
   height: 18px;
   border-radius: 3px;
   object-fit: cover;
@@ -1801,6 +1833,16 @@
   background: color-mix(in srgb, var(--app-ink) 7%, transparent);
 }
 
+.agent-card .line-link.disconnected,
+.agent-card .line-link.disconnected:hover {
+  filter: grayscale(1);
+  opacity: 0.62;
+}
+
+.line-range.disconnected-label {
+  color: var(--app-ink-faint);
+}
+
 
 /* 线路详情、对比等页面的卡片和指标块：同样的亚克力，一层压一层 */
 .card:not(.agent-card),
diff --git a/web/display/src/pages/Line.tsx b/web/display/src/pages/Line.tsx
index cb51dfc..d9d9d50 100644
--- a/web/display/src/pages/Line.tsx
+++ b/web/display/src/pages/Line.tsx
@@ -286,29 +286,16 @@ export function Line() {
 
       <PageError error={line.error ?? series.error} />
 
-      {!s && (loadingNow || !line.error) && !series.error ? (
-        // 还没有数据：先摆出占位，每块上面有进度条
-        <div className="stack" style={{ marginTop: 24 }}>
-          <div className="tiles">
-            {Array.from({ length: 12 }, (_, i) => (
-              <div className="skeleton has-loading" key={i}>
-                <LoadingBar active />
-              </div>
-            ))}
-          </div>
-          <div className="skeleton chart has-loading">
-            <LoadingBar active />
-          </div>
-          <div className="grid cols-2">
-            {[0, 1].map((i) => (
-              <div className="skeleton chart has-loading" key={i}>
-                <LoadingBar active />
-              </div>
-            ))}
-          </div>
+      {!s && loadingNow && !line.error && !series.error ? (
+        <div className="line-loading-state has-loading" role="status" aria-live="polite">
+          <LoadingBar active />
+          <Spinner />
+          <span>正在加载线路数据…</span>
         </div>
       ) : null}
 
+      {!s && !loadingNow && !series.error && line.data ? <div className="line-empty-state">所选时间段暂无测量数据。</div> : null}
+
       {s ? (
         <div className="stack line-metrics" style={{ marginTop: 16 }}>
           <section className="line-metric-surface">
diff --git a/web/display/src/pages/Overview.tsx b/web/display/src/pages/Overview.tsx
index e29457d..b1143fb 100644
--- a/web/display/src/pages/Overview.tsx
+++ b/web/display/src/pages/Overview.tsx
@@ -141,8 +141,18 @@ function NodeCard({ node, labels, infos }: { node: HostItem; labels: string[]; i
 function LineCard({ l, range, infos }: { l: OverviewLineDto; range: OverviewRange; infos: Map<string, NodeInfoDto> }) {
   const probeInfo = infos.get(l.probe_id)
   const agentInfo = infos.get(l.agent_id)
+  const rangeLabel = OVERVIEW_RANGES.find((r) => r.value === range)?.label ?? range
+  const connectionIssue = !l.online
+    ? 'Agent 离线'
+    : l.quic_health?.state === 'retry_wait'
+      ? 'QUIC 拨号失败'
+      : !l.probe_connected
+        ? '测量通道未建立'
+        : l.quic_health && !l.quic_health.connected
+          ? 'QUIC 正在连接'
+          : null
   return (
-    <Link to={`/line/${encodeURIComponent(l.id)}`} className="line-link line-card">
+    <Link to={`/line/${encodeURIComponent(l.id)}`} className={`line-link line-card${connectionIssue ? ' disconnected' : ''}`}>
       <div className="line-top">
         <span className="line-name" title={[l.probe_name, probeInfo?.tag || probeInfo?.version].filter(Boolean).join(' · ')}>
           {probeInfo?.country ? <Flag code={probeInfo.country} /> : null}
@@ -152,13 +162,12 @@ function LineCard({ l, range, infos }: { l: OverviewLineDto; range: OverviewRang
           {agentInfo?.country ? <Flag code={agentInfo.country} /> : null}
           <span className="name">{l.name}</span>
         </span>
-        {!l.probe_connected && l.online ? (
-          <span title="Agent 在线，但这个 Probe 没能和它建立测量会话（控制通道连不上或握手超时）。机器本身可能是通的、ping 也能通，这里说的是测量用的 TCP 控制通道和 QUIC Datagram 数据通道，线路或运营商对它们的处理可能和 ping 不一样。">
-            <Chip tone="warn">测量通道未建立</Chip>
-          </span>
-        ) : (
-          <span className="faint line-range">{OVERVIEW_RANGES.find((r) => r.value === range)?.label ?? range}</span>
-        )}
+        <span
+          className={connectionIssue ? 'line-range disconnected-label' : 'faint line-range'}
+          title={l.quic_health?.state === 'retry_wait' ? `Probe 正在等待退避重试${l.quic_health.retry_in_ms ? `（约 ${Math.ceil(l.quic_health.retry_in_ms / 1000)} 秒）` : ''}。` : !l.probe_connected && l.online ? 'Agent 在线，但 Probe 尚未建立测量会话。' : undefined}
+        >
+          {connectionIssue ? `${connectionIssue} · ${rangeLabel}` : rangeLabel}
+        </span>
       </div>
       <LineStrips lineId={l.id} range={range} m={l.summary.metrics} />
     </Link>
@@ -254,7 +263,7 @@ export function Overview() {
           <IpVersionPicker value={ipVersion} onChange={(v) => { const next = new URLSearchParams(params); next.set('ip_version', v); setCarrier(''); setParams(next, { replace: true }) }} />
           {groups.length > 1 ? <Segmented<'' | CarrierKey> options={[{ value: '', label: '全部' }, ...groups.map((g) => ({ value: g.key, label: g.name }))]} value={carrier} onChange={setCarrier} /> : null}
           <span className="right row">
-            <Segmented<OverviewRange> options={OVERVIEW_RANGES.map((r) => ({ value: r.value, label: `近 ${r.label}` }))} value={range} onChange={setRange} />
+            <Segmented<OverviewRange> options={OVERVIEW_RANGES.map((r) => ({ value: r.value, label: r.label }))} value={range} onChange={setRange} />
             <Segmented
               options={[
                 { value: 'name' as const, label: '名称' },