diff --git a/web/static/css/style.css b/web/static/css/style.css
index 683e2345..25306192 100644
--- a/web/static/css/style.css
+++ b/web/static/css/style.css
@@ -4430,7 +4430,7 @@ html[data-theme="dark"] .new-chat-btn:focus-visible {
 
 .ai-channel-manager {
     border: 1px solid color-mix(in srgb, var(--border-color, #e2e8f0) 88%, transparent);
-    border-radius: 10px;
+    border-radius: 8px;
     background: var(--card-bg, #fff);
     overflow: hidden;
 }
@@ -4446,8 +4446,8 @@ html[data-theme="dark"] .new-chat-btn:focus-visible {
 }
 
 .ai-channel-manager-header h4 {
-    margin: 0 0 8px;
-    font-size: 16px;
+    margin: 0 0 6px;
+    font-size: 17px;
     line-height: 1.25;
 }
 
@@ -4467,55 +4467,75 @@ html[data-theme="dark"] .new-chat-btn:focus-visible {
     color: var(--error-color, #e53e3e);
 }
 
+.ai-channel-header-actions {
+    display: flex;
+    align-items: center;
+    justify-content: flex-end;
+    flex-wrap: wrap;
+    gap: 10px;
+    flex-shrink: 0;
+}
+
 .ai-channel-save-btn {
     flex-shrink: 0;
     min-width: 92px;
 }
 
 .ai-channel-manager-body {
-    display: grid;
-    grid-template-columns: minmax(280px, 360px) minmax(0, 1fr);
+    display: block;
     min-height: 0;
-    align-items: stretch;
     background: var(--card-bg, #fff);
     overflow: visible;
 }
 
-.ai-channel-sidebar {
-    position: relative;
-    display: flex;
-    flex-direction: column;
-    gap: 10px;
-    min-height: 0;
-    overflow: hidden;
-    border-right: 1px solid color-mix(in srgb, var(--border-color, #e2e8f0) 76%, transparent);
-    background: color-mix(in srgb, var(--bg-secondary, #f8fafc) 86%, var(--card-bg, #fff));
-    padding: 18px;
-}
-
-.ai-channel-sidebar-head {
+.ai-channel-switcher {
     display: flex;
     align-items: center;
     justify-content: space-between;
-    gap: 10px;
-    margin-bottom: 0;
-    color: var(--text-secondary, #4a5568);
-    font-size: 12px;
-    font-weight: 700;
-    letter-spacing: 0;
+    gap: 16px;
+    padding: 16px 22px;
+    border-bottom: 1px solid color-mix(in srgb, var(--border-color, #e2e8f0) 72%, transparent);
+    background: color-mix(in srgb, var(--bg-secondary, #f8fafc) 70%, var(--card-bg, #fff));
 }
 
-.ai-channel-bulk-actions {
+.ai-channel-switcher-field {
+    display: grid;
+    grid-template-columns: auto minmax(260px, 420px);
+    align-items: center;
+    gap: 10px;
+    min-width: 0;
+}
+
+.ai-channel-switcher-field label {
+    color: var(--text-secondary, #4a5568);
+    font-size: 13px;
+    font-weight: 700;
+    white-space: nowrap;
+}
+
+.ai-channel-switch-select {
+    width: 100%;
+    min-height: 38px;
+    padding: 0.45rem 2rem 0.45rem 0.7rem;
+    border: 1px solid color-mix(in srgb, var(--border-color, #e2e8f0) 88%, transparent);
+    border-radius: 7px;
+    background: color-mix(in srgb, var(--input-bg, var(--card-bg, #fff)) 92%, transparent);
+    color: var(--text-primary, #2d3748);
+    font-size: 0.875rem;
+}
+
+.ai-channel-switch-select:focus {
+    border-color: color-mix(in srgb, var(--accent-color, #3182ce) 70%, transparent);
+    box-shadow: 0 0 0 3px color-mix(in srgb, var(--accent-color, #3182ce) 12%, transparent);
+    outline: none;
+}
+
+.ai-channel-switcher-actions {
     display: flex;
     align-items: center;
     justify-content: flex-end;
     flex-wrap: wrap;
-    gap: 5px;
-    margin: 0;
-    min-width: 0;
-    padding: 0;
-    border: 0;
-    background: transparent;
+    gap: 8px;
 }
 
 .ai-channel-bulk-btn {
@@ -4523,8 +4543,8 @@ html[data-theme="dark"] .new-chat-btn:focus-visible {
     align-items: center;
     justify-content: center;
     min-width: 0;
-    min-height: 26px;
-    padding: 4px 8px;
+    min-height: 28px;
+    padding: 5px 9px;
     border: 1px solid color-mix(in srgb, var(--border-color, #e2e8f0) 68%, transparent);
     border-radius: 999px;
     background: color-mix(in srgb, var(--card-bg, #fff) 38%, transparent);
@@ -4555,8 +4575,8 @@ html[data-theme="dark"] .new-chat-btn:focus-visible {
 }
 
 .ai-channel-icon-btn {
-    width: 30px;
-    height: 30px;
+    width: 32px;
+    height: 32px;
     border: 1px solid var(--border-color, #e2e8f0);
     border-radius: 8px;
     background: var(--card-bg, #fff);
@@ -4577,19 +4597,7 @@ html[data-theme="dark"] .new-chat-btn:focus-visible {
 }
 
 .ai-channel-list {
-    position: absolute;
-    top: 64px;
-    right: 13px;
-    bottom: 18px;
-    left: 18px;
-    display: flex;
-    flex-direction: column;
-    gap: 10px;
-    min-height: 0;
-    overflow-y: auto;
-    overflow-x: hidden;
-    padding: 2px 5px 2px 1px;
-    scrollbar-gutter: stable;
+    display: none;
 }
 
 .ai-channel-list::-webkit-scrollbar {
@@ -4616,10 +4624,10 @@ html[data-theme="dark"] .new-chat-btn:focus-visible {
     align-items: start;
     gap: 10px;
     width: 100%;
-    min-height: 92px;
-    padding: 12px;
+    min-height: 86px;
+    padding: 11px;
     border: 1px solid color-mix(in srgb, var(--border-color, #e2e8f0) 64%, transparent);
-    border-radius: 8px;
+    border-radius: 7px;
     background: color-mix(in srgb, var(--card-bg, #fff) 70%, transparent);
     color: var(--text-color, #2d3748);
     text-align: left;
@@ -4640,7 +4648,7 @@ html[data-theme="dark"] .new-chat-btn:focus-visible {
     height: 16px;
     margin: 3px 0 0;
     border: 1px solid color-mix(in srgb, var(--text-muted, #718096) 52%, transparent);
-    border-radius: 5px;
+    border-radius: 4px;
     appearance: none;
     -webkit-appearance: none;
     background-color: color-mix(in srgb, var(--card-bg, #fff) 84%, transparent);
@@ -4671,7 +4679,6 @@ html[data-theme="dark"] .new-chat-btn:focus-visible {
 .ai-channel-list-item:hover {
     background: var(--card-bg, #fff);
     border-color: color-mix(in srgb, var(--accent-color, #3182ce) 24%, transparent);
-    transform: translateY(-1px);
 }
 
 .ai-channel-list-item.active {
@@ -4779,17 +4786,17 @@ html[data-theme="dark"] .new-chat-btn:focus-visible {
     min-width: 0;
     min-height: 0;
     overflow-y: visible;
-    padding: 22px 28px 28px;
+    padding: 20px 28px 28px;
     background: var(--card-bg, #fff);
 }
 
 .ai-channel-editor-head {
     display: flex;
-    align-items: flex-start;
+    align-items: center;
     justify-content: space-between;
     gap: 18px;
-    margin-bottom: 18px;
-    padding-bottom: 18px;
+    margin-bottom: 6px;
+    padding-bottom: 16px;
     border-bottom: 1px solid color-mix(in srgb, var(--border-color, #e2e8f0) 72%, transparent);
 }
 
@@ -4804,7 +4811,7 @@ html[data-theme="dark"] .new-chat-btn:focus-visible {
 .ai-channel-editor-head h5 {
     margin: 0;
     color: var(--text-color, #2d3748);
-    font-size: 22px;
+    font-size: 21px;
     font-weight: 700;
     line-height: 1.2;
 }
@@ -4827,8 +4834,9 @@ html[data-theme="dark"] .new-chat-btn:focus-visible {
     color: var(--error-color, #e53e3e);
 }
 
+
 .ai-channel-editor-form {
-    max-width: 980px;
+    max-width: none;
 }
 
 .ai-channel-editor-form .form-group {
@@ -4837,7 +4845,7 @@ html[data-theme="dark"] .new-chat-btn:focus-visible {
 
 .ai-channel-editor-form .form-group label {
     display: block;
-    margin-bottom: 0;
+    margin-bottom: 6px;
     color: var(--text-primary);
     font-size: 0.875rem;
     font-weight: 500;
@@ -4848,10 +4856,14 @@ html[data-theme="dark"] .new-chat-btn:focus-visible {
 .ai-channel-editor-form input[type="password"],
 .ai-channel-editor-form input[type="number"],
 .ai-channel-editor-form select {
+    width: 100%;
     min-height: 42px;
-    border-radius: 8px;
+    padding: 0.5rem 0.75rem;
+    border-radius: 7px;
     border-color: color-mix(in srgb, var(--border-color, #e2e8f0) 88%, transparent);
     background: color-mix(in srgb, var(--input-bg, var(--card-bg, #fff)) 92%, transparent);
+    color: var(--text-color, #2d3748);
+    font-size: 0.875rem;
 }
 
 .ai-channel-editor-form input:focus,
@@ -4863,9 +4875,175 @@ html[data-theme="dark"] .new-chat-btn:focus-visible {
 
 .ai-channel-editor-form .form-hint,
 .ai-channel-editor-form small {
+    display: block;
+    margin-top: 5px;
+    color: var(--text-muted, #718096);
+    font-size: 0.75rem;
     line-height: 1.45;
 }
 
+.ai-channel-form-section {
+    padding: 18px 0;
+    border-bottom: 1px solid color-mix(in srgb, var(--border-color, #e2e8f0) 64%, transparent);
+}
+
+.ai-channel-form-section:last-of-type {
+    border-bottom: 0;
+}
+
+.ai-channel-form-section-head {
+    display: flex;
+    align-items: flex-start;
+    justify-content: space-between;
+    gap: 24px;
+    margin-bottom: 14px;
+}
+
+.ai-channel-form-section-head > div:first-child {
+    max-width: 620px;
+}
+
+.ai-channel-form-section-head h6 {
+    margin: 0;
+    color: var(--text-primary, #1f2937);
+    font-size: 14px;
+    font-weight: 700;
+    line-height: 1.35;
+}
+
+.ai-channel-form-section-head p {
+    margin: 4px 0 0;
+    color: var(--text-muted, #718096);
+    font-size: 12px;
+    line-height: 1.45;
+}
+
+.ai-channel-section-actions {
+    display: flex;
+    align-items: center;
+    justify-content: flex-end;
+    flex-wrap: wrap;
+    gap: 8px;
+    min-width: 210px;
+}
+
+.ai-channel-section-actions .form-inline-result {
+    margin-top: 0;
+}
+
+.ai-channel-section-actions .connection-test-result {
+    display: none;
+    max-width: min(760px, 54vw);
+    padding: 8px 10px;
+    border: 1px solid var(--border-color, #e2e8f0);
+    border-radius: 8px;
+    background: color-mix(in srgb, var(--surface-color, #ffffff) 86%, var(--bg-secondary, #f7fafc));
+    color: var(--text-muted, #718096);
+    font-size: 12px;
+    line-height: 1.45;
+    text-align: left;
+    white-space: pre-wrap;
+    overflow-wrap: anywhere;
+    word-break: break-word;
+}
+
+.ai-channel-section-actions .connection-test-result.is-visible {
+    display: inline-block;
+}
+
+.ai-channel-section-actions .connection-test-result.is-error {
+    border-color: color-mix(in srgb, var(--danger-color, #e53e3e) 42%, var(--border-color, #e2e8f0));
+    background: color-mix(in srgb, var(--danger-color, #e53e3e) 8%, var(--surface-color, #ffffff));
+    color: var(--danger-color, #e53e3e);
+}
+
+.ai-channel-section-actions .connection-test-result.is-success {
+    border-color: color-mix(in srgb, var(--success-color, #38a169) 38%, var(--border-color, #e2e8f0));
+    background: color-mix(in srgb, var(--success-color, #38a169) 9%, var(--surface-color, #ffffff));
+    color: var(--success-color, #38a169);
+}
+
+.ai-channel-form-grid,
+.ai-channel-reasoning-grid {
+    display: grid;
+    grid-template-columns: repeat(auto-fit, minmax(340px, 1fr));
+    column-gap: 16px;
+    row-gap: 14px;
+}
+
+.ai-channel-reasoning-grid {
+    grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
+}
+
+.ai-channel-editor-form .span-2 {
+    grid-column: 1 / -1;
+}
+
+.required-mark {
+    color: var(--error-color, #e53e3e);
+}
+
+.form-inline-result {
+    display: block;
+    margin-top: 6px;
+    color: var(--text-muted, #718096);
+    font-size: 0.75rem;
+    line-height: 1.45;
+}
+
+.ai-channel-reasoning-toggle {
+    margin-top: 8px;
+}
+
+.ai-channel-advanced-section {
+    padding: 10px 0 0;
+    border-bottom: 0;
+}
+
+.ai-channel-advanced-section summary {
+    display: flex;
+    align-items: center;
+    gap: 10px;
+    min-height: 38px;
+    padding: 0;
+    color: var(--text-primary, #1f2937);
+    cursor: pointer;
+    list-style: none;
+}
+
+.ai-channel-advanced-section summary::-webkit-details-marker {
+    display: none;
+}
+
+.ai-channel-advanced-section summary::before {
+    content: "";
+    width: 8px;
+    height: 8px;
+    flex: 0 0 auto;
+    border-right: 2px solid var(--text-muted, #718096);
+    border-bottom: 2px solid var(--text-muted, #718096);
+    transform: rotate(-45deg);
+    transition: transform 0.16s ease;
+}
+
+.ai-channel-advanced-section[open] summary::before {
+    transform: rotate(45deg);
+}
+
+.ai-channel-advanced-section summary strong {
+    display: block;
+    font-size: 14px;
+    line-height: 1.35;
+}
+
+.ai-channel-advanced-section summary small {
+    margin-top: 4px;
+}
+
+.ai-channel-advanced-section[open] .ai-channel-reasoning-grid {
+    margin-top: 14px;
+}
+
 html[data-theme="dark"] .ai-channel-manager {
     background: #111827;
     border-color: rgba(71, 85, 105, 0.42);
@@ -4876,6 +5054,21 @@ html[data-theme="dark"] .ai-channel-manager-header {
     border-bottom-color: rgba(71, 85, 105, 0.34);
 }
 
+html[data-theme="dark"] .ai-channel-switcher {
+    background: #101827;
+    border-bottom-color: rgba(71, 85, 105, 0.34);
+}
+
+html[data-theme="dark"] .ai-channel-switcher-field label {
+    color: #cbd5e1;
+}
+
+html[data-theme="dark"] .ai-channel-switch-select {
+    background: rgba(15, 23, 42, 0.72);
+    border-color: rgba(71, 85, 105, 0.44);
+    color: #e5e7eb;
+}
+
 html[data-theme="dark"] .ai-channel-sidebar {
     background: #101827;
     border-right-color: rgba(71, 85, 105, 0.34);
@@ -4928,6 +5121,42 @@ html[data-theme="dark"] .ai-channel-editor-head {
     border-bottom-color: rgba(71, 85, 105, 0.34);
 }
 
+html[data-theme="dark"] .ai-channel-form-section,
+html[data-theme="dark"] .ai-channel-advanced-section {
+    border-color: rgba(71, 85, 105, 0.34);
+}
+
+html[data-theme="dark"] .ai-channel-form-section-head h6 {
+    color: #e5e7eb;
+}
+
+html[data-theme="dark"] .ai-channel-form-section-head p,
+html[data-theme="dark"] .form-inline-result {
+    color: #94a3b8;
+}
+
+html[data-theme="dark"] .ai-channel-section-actions .connection-test-result {
+    border-color: rgba(71, 85, 105, 0.52);
+    background: rgba(15, 23, 42, 0.74);
+    color: #94a3b8;
+}
+
+html[data-theme="dark"] .ai-channel-section-actions .connection-test-result.is-error {
+    border-color: rgba(248, 113, 113, 0.42);
+    background: rgba(127, 29, 29, 0.22);
+    color: #f87171;
+}
+
+html[data-theme="dark"] .ai-channel-section-actions .connection-test-result.is-success {
+    border-color: rgba(52, 211, 153, 0.38);
+    background: rgba(6, 78, 59, 0.22);
+    color: #34d399;
+}
+
+html[data-theme="dark"] .ai-channel-advanced-section summary {
+    color: #e5e7eb;
+}
+
 html[data-theme="dark"] .ai-channel-icon-btn {
     background: rgba(15, 23, 42, 0.72);
     border-color: rgba(71, 85, 105, 0.44);
@@ -5009,23 +5238,9 @@ html[data-theme="dark"] .ai-channel-editor-form select {
         align-items: stretch;
     }
 
-    .ai-channel-manager-body {
-        grid-template-columns: 1fr;
-        height: auto;
-        overflow: visible;
-    }
-
-    .ai-channel-sidebar {
-        border-right: 0;
-        border-bottom: 1px solid var(--border-color, #e2e8f0);
-        max-height: 420px;
-    }
-
-    .ai-channel-list {
-        position: static;
-        display: grid;
-        grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
-        max-height: 360px;
+    .ai-channel-switcher {
+        align-items: stretch;
+        flex-direction: column;
     }
 
     .ai-channel-editor {
@@ -5035,19 +5250,40 @@ html[data-theme="dark"] .ai-channel-editor-form select {
 
 @media (max-width: 640px) {
     .ai-channel-manager-header,
-    .ai-channel-sidebar,
+    .ai-channel-switcher,
     .ai-channel-editor {
         padding-left: 14px;
         padding-right: 14px;
     }
 
-    .ai-channel-editor-actions {
+    .ai-channel-switcher-actions {
         justify-content: flex-start;
     }
 
-    .ai-channel-bulk-actions {
+    .ai-channel-header-actions {
         justify-content: flex-start;
     }
+
+    .ai-channel-switcher-field {
+        grid-template-columns: 1fr;
+    }
+
+    .ai-channel-form-section-head,
+    .ai-channel-form-grid,
+    .ai-channel-reasoning-grid {
+        grid-template-columns: 1fr;
+    }
+
+    .ai-channel-form-section-head,
+    .ai-channel-section-actions {
+        align-items: stretch;
+        flex-direction: column;
+    }
+
+    .ai-channel-section-actions {
+        justify-content: flex-start;
+        min-width: 0;
+    }
 }
 
 .chat-reasoning-field-label {
@@ -9923,6 +10159,54 @@ html[data-theme="dark"] .robot-binding-service-hint-icon {
     white-space: nowrap;
 }
 
+.settings-custom-select-option--probe .settings-custom-select-label {
+    flex: 1 1 auto;
+}
+
+.settings-custom-select-status {
+    display: inline-flex;
+    flex: 0 0 auto;
+    align-items: center;
+    gap: 5px;
+    max-width: 42%;
+    padding: 2px 6px;
+    border-radius: 999px;
+    background: var(--bg-secondary, #f5f6f8);
+    color: var(--text-secondary, #64748b);
+    font-size: 11px;
+    font-weight: 600;
+    line-height: 1.3;
+}
+
+.settings-custom-select-status-text {
+    overflow: hidden;
+    text-overflow: ellipsis;
+    white-space: nowrap;
+}
+
+.settings-custom-select-status-dot {
+    flex: 0 0 auto;
+    width: 6px;
+    height: 6px;
+    border-radius: 999px;
+    background: currentColor;
+}
+
+.settings-custom-select-status.ready {
+    background: color-mix(in srgb, var(--success-color, #38a169) 11%, transparent);
+    color: var(--success-color, #38a169);
+}
+
+.settings-custom-select-status.failed {
+    background: color-mix(in srgb, var(--danger-color, #e53e3e) 10%, transparent);
+    color: var(--danger-color, #e53e3e);
+}
+
+.settings-custom-select-status.testing {
+    background: color-mix(in srgb, var(--accent-color, #0066ff) 10%, transparent);
+    color: var(--accent-color, #0066ff);
+}
+
 .form-group input:not([type="checkbox"]):not([type="radio"]):focus,
 .form-group select:focus {
     outline: none;
@@ -38401,6 +38685,26 @@ html[data-theme="dark"] #page-settings .audit-custom-select-option.is-selected {
     color: #60a5fa !important;
 }
 
+html[data-theme="dark"] #page-settings .settings-custom-select-status {
+    background: rgba(148, 163, 184, 0.12);
+    color: #94a3b8;
+}
+
+html[data-theme="dark"] #page-settings .settings-custom-select-status.ready {
+    background: rgba(52, 211, 153, 0.14);
+    color: #34d399;
+}
+
+html[data-theme="dark"] #page-settings .settings-custom-select-status.failed {
+    background: rgba(248, 113, 113, 0.14);
+    color: #f87171;
+}
+
+html[data-theme="dark"] #page-settings .settings-custom-select-status.testing {
+    background: rgba(96, 165, 250, 0.14);
+    color: #60a5fa;
+}
+
 /* Chat @ tool mention panel dark theme. */
 html[data-theme="dark"] .mention-suggestions {
     background: #111827 !important;
diff --git a/web/static/i18n/en-US.json b/web/static/i18n/en-US.json
index cfc20d0f..d5a6dc73 100644
--- a/web/static/i18n/en-US.json
+++ b/web/static/i18n/en-US.json
@@ -2603,23 +2603,40 @@
     "aiChannelNew": "New",
     "aiChannelCopy": "Copy",
     "aiChannelDelete": "Delete",
-    "aiChannelHint": "Saved channels appear on the left. Saving writes to ai.channels; the default channel is used by new chats and tasks without an explicit channel.",
+    "aiChannelHint": "Use the dropdown to switch saved channels. Saving writes to ai.channels; the default channel is used by new chats and tasks without an explicit channel.",
     "aiChannelSavedList": "Saved channels",
     "aiChannelListAria": "AI channel list",
     "aiChannelEditing": "Editing",
+    "aiChannelBulkProbe": "Probe all",
+    "aiChannelBulkProbeTitle": "Check whether all complete channels are available",
+    "aiChannelSelectAria": "Select {name}",
     "aiChannelDefaultBadge": "Default",
     "aiChannelReady": "Ready",
+    "aiChannelReadyWithLatency": "Ready{latency}",
     "aiChannelDraft": "Incomplete",
     "aiChannelDefaultMeta": "Default channel",
     "aiChannelCustomMeta": "Custom channel",
     "aiChannelOpenAICompat": "OpenAI compatible",
     "aiChannelModelMissing": "Model missing",
     "aiChannelName": "Channel name",
+    "aiChannelConnectionSection": "Connection",
+    "aiChannelConnectionHint": "Confirm provider, endpoint, key, and model first. Test connection uses these values.",
+    "aiChannelModelSection": "Model and limits",
+    "aiChannelModelHint": "The model name controls routing. Token limits control context and single-response output.",
+    "aiChannelLimitsSection": "Limits",
+    "aiChannelLimitsHint": "Token limits control the context window and single-response output.",
     "aiChannelUntitled": "New Channel",
     "aiChannelDeleteConfirm": "Delete AI channel \"{name}\"?",
     "aiChannelSaved": "Channel saved",
     "aiChannelDefaultSaved": "Default channel saved",
     "aiChannelCount": "{count} channel(s) saved",
+    "aiChannelSaving": "Saving channel...",
+    "aiChannelNewUnsaved": "New channel is not saved yet. Fill it in, then click Save changes.",
+    "aiChannelCopyUnsaved": "Copied channel is not saved yet. Review it, then click Save changes.",
+    "aiChannelDeleted": "Channel deleted",
+    "aiChannelProbeNoComplete": "No complete channel to probe. Fill in Base URL, API Key, and Model first.",
+    "aiChannelProbing": "Probing {count} channel(s)...",
+    "aiChannelProbeDone": "Probe complete: {ok}/{total} ready",
     "apiProvider": "API Provider",
     "providerOpenAI": "OpenAI / OpenAI-compatible API",
     "providerClaude": "Claude (Anthropic Messages API)",
@@ -2799,7 +2816,12 @@
     "testing": "Testing connection...",
     "testSuccess": "Connection successful",
     "testFailed": "Connection failed",
-    "testError": "Test error"
+    "testError": "Test error",
+    "testErrorInvalidApiKey": "API Key is invalid or unauthorized. Check that the key is correct.",
+    "testErrorUnauthorized": "Authentication failed. Check the API Key.",
+    "testErrorForbidden": "Request denied. Check account permissions or model access.",
+    "testErrorModelUnavailable": "Model is unavailable or the model name is incorrect.",
+    "testErrorBaseUrl": "Base URL is unavailable. Check that the endpoint is correct."
   },
   "settingsTerminal": {
     "title": "Terminal",
diff --git a/web/static/i18n/zh-CN.json b/web/static/i18n/zh-CN.json
index 7db25db0..98bd41d8 100644
--- a/web/static/i18n/zh-CN.json
+++ b/web/static/i18n/zh-CN.json
@@ -2591,23 +2591,40 @@
     "aiChannelNew": "新增",
     "aiChannelCopy": "复制",
     "aiChannelDelete": "删除",
-    "aiChannelHint": "已保存的通道会显示在左侧；保存后写入 ai.channels，默认通道用于新对话和未指定通道的任务。",
+    "aiChannelHint": "通过下拉切换已保存通道；保存后写入 ai.channels，默认通道用于新对话和未指定通道的任务。",
     "aiChannelSavedList": "已保存通道",
     "aiChannelListAria": "AI 通道列表",
     "aiChannelEditing": "正在编辑",
+    "aiChannelBulkProbe": "批量探活",
+    "aiChannelBulkProbeTitle": "检测全部完整通道是否可用",
+    "aiChannelSelectAria": "选择 {name}",
     "aiChannelDefaultBadge": "默认",
     "aiChannelReady": "可用",
+    "aiChannelReadyWithLatency": "可用{latency}",
     "aiChannelDraft": "待完善",
     "aiChannelDefaultMeta": "默认通道",
     "aiChannelCustomMeta": "自定义通道",
     "aiChannelOpenAICompat": "OpenAI 兼容",
     "aiChannelModelMissing": "未填写模型",
     "aiChannelName": "通道名称",
+    "aiChannelConnectionSection": "连接信息",
+    "aiChannelConnectionHint": "先确认服务商、地址、密钥和模型，测试连接会使用这些信息。",
+    "aiChannelModelSection": "模型与额度",
+    "aiChannelModelHint": "模型名决定请求路由，Token 上限控制上下文和单次输出。",
+    "aiChannelLimitsSection": "额度设置",
+    "aiChannelLimitsHint": "Token 上限控制上下文窗口和单次输出。",
     "aiChannelUntitled": "新通道",
     "aiChannelDeleteConfirm": "确定删除 AI 通道「{name}」吗？",
     "aiChannelSaved": "通道已保存",
     "aiChannelDefaultSaved": "已设为默认通道",
     "aiChannelCount": "已保存 {count} 个通道",
+    "aiChannelSaving": "正在保存通道...",
+    "aiChannelNewUnsaved": "新通道尚未保存，填写后点击「保存更改」。",
+    "aiChannelCopyUnsaved": "复制的通道尚未保存，确认后点击「保存更改」。",
+    "aiChannelDeleted": "通道已删除",
+    "aiChannelProbeNoComplete": "没有可探活的完整通道，请先填写 Base URL、API Key 和模型",
+    "aiChannelProbing": "正在探活 {count} 个通道...",
+    "aiChannelProbeDone": "探活完成：{ok}/{total} 可用",
     "apiProvider": "API 提供商",
     "providerOpenAI": "OpenAI / 兼容 OpenAI 协议",
     "providerClaude": "Claude (Anthropic Messages API)",
@@ -2787,7 +2804,12 @@
     "testing": "测试中...",
     "testSuccess": "连接成功",
     "testFailed": "连接失败",
-    "testError": "测试出错"
+    "testError": "测试出错",
+    "testErrorInvalidApiKey": "API Key 无效或无权限，请检查密钥是否填写正确",
+    "testErrorUnauthorized": "认证失败，请检查 API Key",
+    "testErrorForbidden": "请求被拒绝，请检查账号权限或模型访问权限",
+    "testErrorModelUnavailable": "模型不可用或模型名不正确，请检查模型名称",
+    "testErrorBaseUrl": "Base URL 不可用，请检查地址是否正确"
   },
   "settingsTerminal": {
     "title": "终端",
diff --git a/web/static/js/settings.js b/web/static/js/settings.js
index 8187e287..7e575dde 100644
--- a/web/static/js/settings.js
+++ b/web/static/js/settings.js
@@ -142,6 +142,19 @@ function syncSettingsCustomSelect(select) {
 
         item.appendChild(check);
         item.appendChild(label);
+
+        if (select.id === 'ai-channel-select') {
+            const probeStatus = option.dataset.probeStatus || '';
+            const probeMessage = option.dataset.probeMessage || '';
+            if (probeStatus) {
+                item.classList.add('settings-custom-select-option--probe', `probe-${probeStatus}`);
+                const status = document.createElement('span');
+                status.className = `settings-custom-select-status ${probeStatus}`;
+                status.innerHTML = `<span class="settings-custom-select-status-dot" aria-hidden="true"></span><span class="settings-custom-select-status-text"></span>`;
+                status.querySelector('.settings-custom-select-status-text').textContent = probeMessage || probeStatus;
+                item.appendChild(status);
+            }
+        }
         reg.menu.appendChild(item);
     });
 }
@@ -2557,6 +2570,90 @@ function writeAIChannelToMainForm(id) {
     const allowEl = document.getElementById('openai-reasoning-allow-client');
     if (allowEl) allowEl.checked = r.allow_client_reasoning !== false;
     syncModelListFetchButtons();
+    syncAIChannelEditorPreview();
+}
+
+function displayAIChannelName(id, ch) {
+    const name = String(ch?.name || '').trim();
+    if ((name === '新通道' || name === 'New Channel') && !String(ch?.model || '').trim()) {
+        return settingsT('settingsBasic.aiChannelUntitled', name || id);
+    }
+    return name || id;
+}
+
+function aiChannelSelectLabel(id, ch) {
+    const marker = id === currentConfig?.ai?.default_channel ? ' *' : '';
+    return `${displayAIChannelName(id, ch)}${marker} · ${ch?.model || '-'}`;
+}
+
+function aiChannelOptionProbeMeta(id) {
+    const probe = aiChannelProbeResults[id];
+    if (!probe) return null;
+    const status = probe.status || '';
+    if (!['testing', 'ready', 'failed'].includes(status)) return null;
+    return {
+        status,
+        message: probe.message || (status === 'ready'
+            ? settingsT('settingsBasic.aiChannelReady', '可用')
+            : status === 'testing'
+                ? settingsT('settingsBasic.testing', '测试中...')
+                : settingsT('settingsBasic.testFailed', '连接失败'))
+    };
+}
+
+function updateAIChannelSelectOption(id) {
+    const select = document.getElementById('ai-channel-select');
+    if (!select || !currentConfig?.ai?.channels) return;
+    const channelId = normalizeAIChannelId(id || selectedAIChannelId || currentConfig.ai.default_channel || 'default');
+    const ch = currentConfig.ai.channels[channelId];
+    if (!ch) return;
+    const opt = Array.from(select.options).find((option) => option.value === channelId);
+    if (opt) {
+        opt.textContent = aiChannelSelectLabel(channelId, ch);
+        const probeMeta = aiChannelOptionProbeMeta(channelId);
+        if (probeMeta) {
+            opt.dataset.probeStatus = probeMeta.status;
+            opt.dataset.probeMessage = probeMeta.message;
+        } else {
+            delete opt.dataset.probeStatus;
+            delete opt.dataset.probeMessage;
+        }
+        select.value = channelId;
+        select.selectedIndex = opt.index;
+    }
+    if (typeof syncSettingsCustomSelect === 'function') {
+        syncSettingsCustomSelect(select);
+    }
+}
+
+function syncSelectedAIChannelUI() {
+    updateAIChannelSelectOption(selectedAIChannelId);
+    updateAIChannelEditorChrome(selectedAIChannelId);
+    renderAIChannelList();
+}
+
+function syncAIChannelEditorPreview() {
+    if (!currentConfig?.ai?.channels || !selectedAIChannelId || !currentConfig.ai.channels[selectedAIChannelId]) return;
+    const id = normalizeAIChannelId(selectedAIChannelId);
+    const next = readAIChannelFromMainForm(id);
+    currentConfig.ai.channels[id] = next;
+    syncSelectedAIChannelUI();
+}
+
+function bindAIChannelEditorPreviewSync() {
+    const ids = [
+        'ai-channel-name',
+        'openai-provider',
+        'openai-base-url',
+        'openai-model'
+    ];
+    ids.forEach((fieldId) => {
+        const el = document.getElementById(fieldId);
+        if (!el || el.dataset.aiChannelPreviewBound === '1') return;
+        el.dataset.aiChannelPreviewBound = '1';
+        const eventName = el.tagName === 'SELECT' ? 'change' : 'input';
+        el.addEventListener(eventName, syncAIChannelEditorPreview);
+    });
 }
 
 function renderAIChannelSelect() {
@@ -2570,16 +2667,24 @@ function renderAIChannelSelect() {
         const ch = currentConfig.ai.channels[id] || {};
         const opt = document.createElement('option');
         opt.value = id;
-        const marker = id === currentConfig.ai.default_channel ? ' *' : '';
-        opt.textContent = `${ch.name || id}${marker} · ${ch.model || '-'}`;
+        opt.textContent = aiChannelSelectLabel(id, ch);
+        const probeMeta = aiChannelOptionProbeMeta(id);
+        if (probeMeta) {
+            opt.dataset.probeStatus = probeMeta.status;
+            opt.dataset.probeMessage = probeMeta.message;
+        }
         select.appendChild(opt);
     });
     selectedAIChannelId = selectedAIChannelId && currentConfig.ai.channels[selectedAIChannelId]
         ? selectedAIChannelId
         : currentConfig.ai.default_channel;
     select.value = selectedAIChannelId;
-    renderAIChannelList(ids);
+    updateAIChannelSelectOption(selectedAIChannelId);
+    if (typeof syncSettingsCustomSelect === 'function') {
+        syncSettingsCustomSelect(select);
+    }
     updateAIChannelEditorChrome(selectedAIChannelId);
+    renderAIChannelList(ids);
     const countLabel = typeof window.t === 'function'
         ? window.t('settingsBasic.aiChannelCount').replace('{count}', String(ids.length))
         : `已保存 ${ids.length} 个通道`;
@@ -2621,7 +2726,7 @@ function renderAIChannelList(ids) {
         checkbox.type = 'checkbox';
         checkbox.className = 'ai-channel-bulk-check';
         checkbox.checked = selectedAIChannelBulkIds.has(id);
-        checkbox.setAttribute('aria-label', `选择 ${ch.name || id}`);
+        checkbox.setAttribute('aria-label', settingsT('settingsBasic.aiChannelSelectAria', '选择 {name}').replace('{name}', displayAIChannelName(id, ch)));
         checkbox.onclick = (event) => {
             event.stopPropagation();
             if (checkbox.checked) {
@@ -2631,6 +2736,7 @@ function renderAIChannelList(ids) {
             }
             item.classList.toggle('checked', checkbox.checked);
         };
+        const displayName = displayAIChannelName(id, ch);
         const defaultBadge = isDefault ? `<span class="ai-channel-badge">${escapeAIChannelHtml(settingsT('settingsBasic.aiChannelDefaultBadge', '默认'))}</span>` : '';
         let statusText = isComplete
             ? settingsT('settingsBasic.aiChannelReady', '可用')
@@ -2645,7 +2751,7 @@ function renderAIChannelList(ids) {
         body.innerHTML = `
             <div class="ai-channel-list-main">
                 <span class="ai-channel-status-dot ${statusClass}" aria-hidden="true"></span>
-                <strong title="${escapeAIChannelHtml(ch.name || id)}">${escapeAIChannelHtml(ch.name || id)}</strong>
+                <strong title="${escapeAIChannelHtml(displayName)}">${escapeAIChannelHtml(displayName)}</strong>
                 ${defaultBadge}
             </div>
             <div class="ai-channel-list-meta" title="${escapeAIChannelHtml(ch.model || '-')} · ${escapeAIChannelHtml(channelHostLabel(ch.base_url))}">${escapeAIChannelHtml(ch.model || '-')} · ${escapeAIChannelHtml(channelHostLabel(ch.base_url))}</div>
@@ -2674,7 +2780,7 @@ function updateAIChannelEditorChrome(id) {
     const ch = ai.channels[channelId] || {};
     const title = document.getElementById('ai-channel-editor-title');
     const meta = document.getElementById('ai-channel-editor-meta');
-    if (title) title.textContent = ch.name || channelId;
+    if (title) title.textContent = displayAIChannelName(channelId, ch);
     if (meta) {
         const parts = [
             channelId === ai.default_channel
@@ -2699,6 +2805,41 @@ function validateSelectedAIChannelPayload(ch) {
     return '';
 }
 
+function resolveSavedAIChannelId(ai, preferredId, preferredPayload) {
+    const channels = ai?.channels || {};
+    const normalizedPreferred = normalizeAIChannelId(preferredId || '');
+    if (normalizedPreferred && channels[normalizedPreferred]) return normalizedPreferred;
+
+    const payload = preferredPayload || {};
+    const targetName = String(payload.name || '').trim();
+    const targetModel = String(payload.model || '').trim();
+    const targetBaseUrl = String(payload.base_url || '').trim();
+    const targetProvider = String(payload.provider || '').trim();
+    const ids = Object.keys(channels).sort();
+    const matched = ids.find((id) => {
+        const ch = channels[id] || {};
+        return String(ch.name || '').trim() === targetName
+            && String(ch.model || '').trim() === targetModel
+            && String(ch.base_url || '').trim() === targetBaseUrl
+            && String(ch.provider || '').trim() === targetProvider;
+    });
+    return matched || ai?.default_channel || ids[0] || normalizedPreferred || 'default';
+}
+
+async function refreshAIChannelsFromServer(preferredId, preferredPayload) {
+    const response = await apiFetch('/api/config');
+    if (!response.ok) return false;
+    currentConfig = await response.json();
+    currentConfig.ai = ensureAIConfigShape(currentConfig);
+    selectedAIChannelId = resolveSavedAIChannelId(currentConfig.ai, preferredId, preferredPayload);
+    renderAIChannelSelect();
+    writeAIChannelToMainForm(selectedAIChannelId);
+    if (typeof populateChatAIChannelSelect === 'function') {
+        populateChatAIChannelSelect(currentConfig.ai);
+    }
+    return true;
+}
+
 async function persistAIChannelsToServer(successMessage, options = {}) {
     if (typeof requirePermission === 'function' && !requirePermission('config:write')) return false;
     if (!currentConfig) currentConfig = {};
@@ -2714,7 +2855,7 @@ async function persistAIChannelsToServer(successMessage, options = {}) {
         return false;
     }
     renderAIChannelSelect();
-    showAIChannelSaveHint('正在保存通道...', true);
+    showAIChannelSaveHint(settingsT('settingsBasic.aiChannelSaving', '正在保存通道...'), true);
     try {
         const shouldMergeLatest = options.mergeLatest !== false;
         const latestResponse = shouldMergeLatest ? await apiFetch('/api/config') : null;
@@ -2744,17 +2885,7 @@ async function persistAIChannelsToServer(successMessage, options = {}) {
             const error = await applyResponse.json().catch(() => ({}));
             throw new Error(error.error || '应用通道失败');
         }
-        const response = await apiFetch('/api/config');
-        if (response.ok) {
-            currentConfig = await response.json();
-            currentConfig.ai = ensureAIConfigShape(currentConfig);
-            selectedAIChannelId = currentConfig.ai.channels[id] ? id : currentConfig.ai.default_channel;
-            renderAIChannelSelect();
-            writeAIChannelToMainForm(selectedAIChannelId);
-            if (typeof populateChatAIChannelSelect === 'function') {
-                populateChatAIChannelSelect(currentConfig.ai);
-            }
-        }
+        await refreshAIChannelsFromServer(id, channelPayload);
         showAIChannelSaveHint(successMessage || '通道已保存', true);
         return true;
     } catch (error) {
@@ -2768,7 +2899,7 @@ async function persistAIConfigOnlyToServer(successMessage) {
     if (typeof requirePermission === 'function' && !requirePermission('config:write')) return false;
     if (!currentConfig) return false;
     currentConfig.ai = ensureAIConfigShape(currentConfig);
-    showAIChannelSaveHint('正在保存通道...', true);
+    showAIChannelSaveHint(settingsT('settingsBasic.aiChannelSaving', '正在保存通道...'), true);
     try {
         const updateResponse = await apiFetch('/api/config', {
             method: 'PUT',
@@ -2784,9 +2915,7 @@ async function persistAIConfigOnlyToServer(successMessage) {
             const error = await applyResponse.json().catch(() => ({}));
             throw new Error(error.error || '应用通道失败');
         }
-        if (typeof populateChatAIChannelSelect === 'function') {
-            populateChatAIChannelSelect(currentConfig.ai);
-        }
+        await refreshAIChannelsFromServer(selectedAIChannelId);
         showAIChannelSaveHint(successMessage || '通道已保存', true);
         return true;
     } catch (error) {
@@ -2850,7 +2979,7 @@ function createAIChannelFromForm() {
     selectedAIChannelId = id;
     renderAIChannelSelect();
     writeAIChannelToMainForm(id);
-    showAIChannelSaveHint('新通道尚未保存，填写后点击「保存更改」。', true);
+    showAIChannelSaveHint(settingsT('settingsBasic.aiChannelNewUnsaved', '新通道尚未保存，填写后点击「保存更改」。'), true);
 }
 
 function copyAIChannelFromForm() {
@@ -2862,10 +2991,10 @@ function copyAIChannelFromForm() {
     selectedAIChannelId = id;
     renderAIChannelSelect();
     writeAIChannelToMainForm(id);
-    showAIChannelSaveHint('复制的通道尚未保存，确认后点击「保存更改」。', true);
+    showAIChannelSaveHint(settingsT('settingsBasic.aiChannelCopyUnsaved', '复制的通道尚未保存，确认后点击「保存更改」。'), true);
 }
 
-function deleteSelectedAIChannel() {
+async function deleteSelectedAIChannel() {
     if (!currentConfig) return;
     currentConfig.ai = ensureAIConfigShape(currentConfig);
     const ids = Object.keys(currentConfig.ai.channels || {});
@@ -2883,10 +3012,21 @@ function deleteSelectedAIChannel() {
         return;
     }
     delete currentConfig.ai.channels[id];
-    currentConfig.ai.default_channel = Object.keys(currentConfig.ai.channels).sort()[0];
+    delete aiChannelProbeResults[id];
+    selectedAIChannelBulkIds.delete(id);
+
+    const remainingIds = Object.keys(currentConfig.ai.channels || {}).sort();
+    if (!currentConfig.ai.channels[currentConfig.ai.default_channel]) {
+        currentConfig.ai.default_channel = remainingIds[0];
+    }
+    selectedAIChannelId = currentConfig.ai.default_channel || remainingIds[0];
     renderAIChannelSelect();
-    writeAIChannelToMainForm(currentConfig.ai.default_channel);
-    persistAIChannelsToServer('通道已删除', { mergeLatest: false });
+    writeAIChannelToMainForm(selectedAIChannelId);
+    const saved = await persistAIConfigOnlyToServer(settingsT('settingsBasic.aiChannelDeleted', '通道已删除'));
+    if (saved) {
+        renderAIChannelSelect();
+        writeAIChannelToMainForm(selectedAIChannelId);
+    }
 }
 
 function selectedOrAllAIChannelIdsForProbe() {
@@ -2904,12 +3044,13 @@ async function probeSelectedAIChannels() {
     if (typeof requirePermission === 'function' && !requirePermission('config:write')) return;
     const ids = selectedOrAllAIChannelIdsForProbe();
     if (!ids.length) {
-        alert('没有可探活的完整通道，请先填写 Base URL、API Key 和模型');
+        alert(settingsT('settingsBasic.aiChannelProbeNoComplete', '没有可探活的完整通道，请先填写 Base URL、API Key 和模型'));
         return;
     }
-    showAIChannelSaveHint(`正在探活 ${ids.length} 个通道...`, true);
+    showAIChannelSaveHint(settingsT('settingsBasic.aiChannelProbing', '正在探活 {count} 个通道...').replace('{count}', String(ids.length)), true);
     ids.forEach((id) => {
-        aiChannelProbeResults[id] = { status: 'testing', message: '测试中...' };
+        aiChannelProbeResults[id] = { status: 'testing', message: settingsT('settingsBasic.testing', '测试中...') };
+        updateAIChannelSelectOption(id);
     });
     renderAIChannelList();
     let okCount = 0;
@@ -2933,13 +3074,14 @@ async function probeSelectedAIChannels() {
             if (response.ok && result.success) {
                 okCount += 1;
                 const latency = result.latency_ms ? ` ${result.latency_ms}ms` : '';
-                aiChannelProbeResults[id] = { status: 'ready', message: `可用${latency}` };
+                aiChannelProbeResults[id] = { status: 'ready', message: settingsT('settingsBasic.aiChannelReadyWithLatency', '可用{latency}').replace('{latency}', latency) };
             } else {
-                aiChannelProbeResults[id] = { status: 'failed', message: (result.error || '连接失败') };
+                aiChannelProbeResults[id] = { status: 'failed', message: formatConnectionTestError(result.error || settingsT('settingsBasic.testFailed', '连接失败')).message };
             }
         } catch (error) {
-            aiChannelProbeResults[id] = { status: 'failed', message: error.message || '测试出错' };
+            aiChannelProbeResults[id] = { status: 'failed', message: formatConnectionTestError(error.message || settingsT('settingsBasic.testError', '测试出错')).message };
         }
+        updateAIChannelSelectOption(id);
         renderAIChannelList();
     }
     const workers = Array.from({ length: Math.min(AI_CHANNEL_PROBE_CONCURRENCY, ids.length) }, async function () {
@@ -2948,7 +3090,7 @@ async function probeSelectedAIChannels() {
         }
     });
     await Promise.all(workers);
-    showAIChannelSaveHint(`探活完成：${okCount}/${ids.length} 可用`, okCount === ids.length);
+    showAIChannelSaveHint(settingsT('settingsBasic.aiChannelProbeDone', '探活完成：{ok}/{total} 可用').replace('{ok}', String(okCount)).replace('{total}', String(ids.length)), okCount === ids.length);
 }
 
 async function deleteCheckedAIChannels() {
@@ -2997,7 +3139,17 @@ if (typeof window !== 'undefined') {
     window.deleteCheckedAIChannels = deleteCheckedAIChannels;
 }
 
+if (typeof document !== 'undefined' && !document.__aiChannelI18nBound) {
+    document.__aiChannelI18nBound = true;
+    document.addEventListener('languagechange', function () {
+        if (!currentConfig?.ai) return;
+        renderAIChannelSelect();
+        updateAIChannelEditorChrome(selectedAIChannelId || currentConfig.ai.default_channel);
+    });
+}
+
 function initModelListControls() {
+    bindAIChannelEditorPreviewSync();
     const providerEl = document.getElementById('openai-provider');
     if (providerEl && !providerEl.dataset.modelListBound) {
         providerEl.dataset.modelListBound = '1';
@@ -3048,6 +3200,9 @@ function bindModelSelect(scope) {
         if (!select.value) return;
         const input = document.getElementById(inputId);
         if (input) input.value = select.value;
+        if (scope === 'openai') {
+            syncAIChannelEditorPreview();
+        }
     });
 }
 
@@ -3430,6 +3585,36 @@ async function testHitlAuditModelConnection() {
     }
 }
 
+function formatConnectionTestError(errorText) {
+    const raw = String(errorText || '').trim() || settingsT('settingsBasic.testError', '测试出错');
+    return {
+        message: raw,
+        detail: raw
+    };
+}
+
+function setConnectionTestResult(resultEl, state, message, title) {
+    if (!resultEl) return;
+    resultEl.classList.remove('is-error', 'is-success', 'is-muted', 'is-visible');
+    resultEl.style.color = '';
+    resultEl.textContent = message || '';
+    resultEl.title = title || '';
+    if (message) {
+        resultEl.classList.add('is-visible', state || 'is-muted');
+    }
+}
+
+function showConnectionTestFailure(resultEl, errorText) {
+    if (!resultEl) return;
+    const formatted = formatConnectionTestError(errorText);
+    setConnectionTestResult(
+        resultEl,
+        'is-error',
+        (typeof window.t === 'function' ? window.t('settingsBasic.testFailed') : '连接失败') + ': ' + formatted.message,
+        formatted.detail || formatted.message
+    );
+}
+
 // 测试OpenAI连接
 async function testOpenAIConnection() {
     const btn = document.getElementById('test-openai-btn');
@@ -3441,15 +3626,13 @@ async function testOpenAIConnection() {
     const model = document.getElementById('openai-model').value.trim();
 
     if (!apiKey || !model) {
-        resultEl.style.color = 'var(--danger-color, #e53e3e)';
-        resultEl.textContent = typeof window.t === 'function' ? window.t('settingsBasic.testFillRequired') : '请先填写 API Key 和模型';
+        setConnectionTestResult(resultEl, 'is-error', typeof window.t === 'function' ? window.t('settingsBasic.testFillRequired') : '请先填写 API Key 和模型');
         return;
     }
 
     btn.style.pointerEvents = 'none';
     btn.style.opacity = '0.5';
-    resultEl.style.color = 'var(--text-muted, #888)';
-    resultEl.textContent = typeof window.t === 'function' ? window.t('settingsBasic.testing') : '测试中...';
+    setConnectionTestResult(resultEl, 'is-muted', typeof window.t === 'function' ? window.t('settingsBasic.testing') : '测试中...');
 
     try {
         const response = await apiFetch('/api/config/test-openai', {
@@ -3466,17 +3649,14 @@ async function testOpenAIConnection() {
         const result = await response.json();
 
         if (result.success) {
-            resultEl.style.color = 'var(--success-color, #38a169)';
             const latency = result.latency_ms ? ` (${result.latency_ms}ms)` : '';
             const modelInfo = result.model ? ` [${result.model}]` : '';
-            resultEl.textContent = (typeof window.t === 'function' ? window.t('settingsBasic.testSuccess') : '连接成功') + modelInfo + latency;
+            setConnectionTestResult(resultEl, 'is-success', (typeof window.t === 'function' ? window.t('settingsBasic.testSuccess') : '连接成功') + modelInfo + latency);
         } else {
-            resultEl.style.color = 'var(--danger-color, #e53e3e)';
-            resultEl.textContent = (typeof window.t === 'function' ? window.t('settingsBasic.testFailed') : '连接失败') + ': ' + (result.error || '未知错误');
+            showConnectionTestFailure(resultEl, result.error || '未知错误');
         }
     } catch (error) {
-        resultEl.style.color = 'var(--danger-color, #e53e3e)';
-        resultEl.textContent = (typeof window.t === 'function' ? window.t('settingsBasic.testError') : '测试出错') + ': ' + error.message;
+        showConnectionTestFailure(resultEl, error.message || '测试出错');
     } finally {
         btn.style.pointerEvents = '';
         btn.style.opacity = '';
diff --git a/web/templates/index.html b/web/templates/index.html
index 16b5bd3a..2e488084 100644
--- a/web/templates/index.html
+++ b/web/templates/index.html
@@ -3446,23 +3446,27 @@
                                         <div class="ai-channel-manager-header">
                                             <div>
                                                 <h4 data-i18n="settingsBasic.openaiConfig">AI 通道配置</h4>
-                                                <p id="ai-channel-save-hint" class="ai-channel-manager-hint" data-i18n="settingsBasic.aiChannelHint">已保存的通道会显示在左侧；保存后写入 ai.channels，默认通道用于新对话和未指定通道的任务。</p>
+                                                <p id="ai-channel-save-hint" class="ai-channel-manager-hint" data-i18n="settingsBasic.aiChannelHint">通过下拉切换已保存通道；保存后写入 ai.channels，默认通道用于新对话和未指定通道的任务。</p>
+                                            </div>
+                                            <div class="ai-channel-header-actions">
+                                                <button type="button" class="btn-secondary" onclick="createAIChannelFromForm()" data-i18n="settingsBasic.aiChannelNew">新增</button>
+                                                <button type="button" class="btn-primary ai-channel-save-btn" onclick="saveSelectedAIChannel()" data-i18n="settingsBasic.aiChannelSave">保存更改</button>
                                             </div>
-                                            <button type="button" class="btn-primary ai-channel-save-btn" onclick="saveSelectedAIChannel()" data-i18n="settingsBasic.aiChannelSave">保存更改</button>
                                         </div>
                                         <div class="ai-channel-manager-body">
-                                            <aside class="ai-channel-sidebar" aria-label="AI 通道列表" data-i18n="settingsBasic.aiChannelListAria" data-i18n-attr="aria-label">
-                                                <div class="ai-channel-sidebar-head">
-                                                    <span data-i18n="settingsBasic.aiChannelSavedList">已保存通道</span>
-                                                    <div class="ai-channel-bulk-actions">
-                                                        <button type="button" class="ai-channel-bulk-btn" onclick="probeSelectedAIChannels()" title="检测所选或全部完整通道是否可用">批量探活</button>
-                                                        <button type="button" class="ai-channel-bulk-btn danger" onclick="deleteCheckedAIChannels()" title="删除已勾选的非默认通道">删除所选</button>
-                                                        <button type="button" class="ai-channel-icon-btn" onclick="createAIChannelFromForm()" title="新增通道" aria-label="新增通道">+</button>
-                                                    </div>
+                                            <div class="ai-channel-switcher" aria-label="AI 通道选择" data-i18n="settingsBasic.aiChannelListAria" data-i18n-attr="aria-label">
+                                                <div class="ai-channel-switcher-field">
+                                                    <label for="ai-channel-select" data-i18n="settingsBasic.aiChannelCurrent">当前通道</label>
+                                                    <select id="ai-channel-select" class="ai-channel-switch-select" onchange="selectAIChannelForEditing(this.value)"></select>
+                                                </div>
+                                                <div class="ai-channel-switcher-actions">
+                                                    <button type="button" class="btn-secondary" onclick="probeSelectedAIChannels()" data-i18n="settingsBasic.aiChannelBulkProbe" data-i18n-title="settingsBasic.aiChannelBulkProbeTitle" data-i18n-attr="title">批量探活</button>
+                                                    <button type="button" class="btn-secondary" onclick="copyAIChannelFromForm()" data-i18n="settingsBasic.aiChannelCopy">复制</button>
+                                                    <button type="button" class="btn-secondary" onclick="setSelectedAIChannelDefault()" data-i18n="settingsBasic.aiChannelSetDefault">设为默认</button>
+                                                    <button type="button" class="btn-secondary danger" onclick="deleteSelectedAIChannel()" data-i18n="settingsBasic.aiChannelDelete">删除</button>
                                                 </div>
-                                                <select id="ai-channel-select" class="ai-channel-native-select" onchange="selectAIChannelForEditing(this.value)" aria-hidden="true" tabindex="-1"></select>
                                                 <div id="ai-channel-list" class="ai-channel-list" aria-live="polite"></div>
-                                            </aside>
+                                            </div>
                                             <div class="ai-channel-editor">
                                                 <div class="ai-channel-editor-head">
                                                     <div>
@@ -3470,91 +3474,118 @@
                                                         <h5 id="ai-channel-editor-title">-</h5>
                                                         <p id="ai-channel-editor-meta">-</p>
                                                     </div>
-                                                    <div class="ai-channel-editor-actions">
-                                                        <button type="button" class="btn-secondary" onclick="setSelectedAIChannelDefault()" data-i18n="settingsBasic.aiChannelSetDefault">设为默认</button>
-                                                        <button type="button" class="btn-secondary" onclick="copyAIChannelFromForm()" data-i18n="settingsBasic.aiChannelCopy">复制</button>
-                                                        <button type="button" class="btn-secondary danger" onclick="deleteSelectedAIChannel()" data-i18n="settingsBasic.aiChannelDelete">删除</button>
-                                                    </div>
                                                 </div>
                                                 <div class="settings-form ai-channel-editor-form">
-                                        <div class="form-group">
-                                            <label for="ai-channel-name" data-i18n="settingsBasic.aiChannelName">通道名称</label>
-                                            <input type="text" id="ai-channel-name" placeholder="Qwen Max" maxlength="24" />
-                                        </div>
-                                        <div class="form-group">
-                                            <label for="openai-provider" data-i18n="settingsBasic.apiProvider">API 提供商</label>
-	                                            <select id="openai-provider" style="width: 100%; padding: 0.5rem 0.75rem; border: 1px solid var(--border-color, #e2e8f0); border-radius: 6px; background: var(--card-bg, #fff); color: var(--text-color, #2d3748); font-size: 0.875rem;">
-	                                                <option value="openai_compatible" data-i18n="settingsBasic.providerOpenAI">OpenAI / 兼容 OpenAI 协议</option>
-	                                                <option value="claude" data-i18n="settingsBasic.providerClaude">Claude (Anthropic Messages API)</option>
-	                                            </select>
-                                        </div>
-                                        <div class="form-group">
-                                            <label for="openai-base-url">Base URL <span style="color: red;">*</span></label>
-                                            <input type="text" id="openai-base-url" data-i18n="settingsBasic.openaiBaseUrlPlaceholder" data-i18n-attr="placeholder" placeholder="https://api.openai.com/v1" required />
-                                        </div>
-                                        <div class="form-group">
-                                            <label for="openai-api-key">API Key <span style="color: red;">*</span></label>
-                                            <input type="password" id="openai-api-key" data-i18n="settingsBasic.openaiApiKeyPlaceholder" data-i18n-attr="placeholder" placeholder="输入OpenAI API Key" required />
-                                        </div>
-                                        <div class="form-group">
-                                            <label for="openai-model"><span data-i18n="settingsBasic.model">模型</span> <span style="color: red;">*</span></label>
-                                            <div class="model-pick-row">
-                                                <input type="text" id="openai-model" class="model-pick-input" data-i18n="settingsBasic.modelPlaceholder" data-i18n-attr="placeholder" placeholder="gpt-4" required />
-                                                <select id="openai-model-select" class="model-pick-native" style="display: none;" title="" aria-hidden="true" tabindex="-1">
-                                                    <option value="" disabled data-i18n="settingsBasic.modelsListSelectPlaceholder">请选择模型</option>
-                                                </select>
-                                                <a href="javascript:void(0)" id="fetch-openai-models-btn" class="model-pick-fetch-link" onclick="fetchModelList('openai')" data-i18n="settingsBasic.fetchModels">获取列表</a>
-                                            </div>
-                                            <small id="fetch-openai-models-hint" class="form-hint" style="display: none; font-size: 0.75rem; margin-top: 4px;"></small>
-                                            <span id="fetch-openai-models-result" style="font-size: 0.75rem; margin-top: 2px; display: block;"></span>
-                                        </div>
-                                        <div class="form-group">
-                                            <label for="openai-max-total-tokens"><span data-i18n="settingsBasic.maxTotalTokens">最大上下文 Token 数</span></label>
-                                            <input type="number" id="openai-max-total-tokens" data-i18n="settingsBasic.maxTotalTokensPlaceholder" data-i18n-attr="placeholder" placeholder="120000" min="1000" step="1000" />
-                                            <small style="color: var(--text-muted, #718096); font-size: 0.75rem;" data-i18n="settingsBasic.maxTotalTokensHint">内存压缩和攻击链构建共用此配置，默认 120000</small>
-                                        </div>
-                                        <div class="form-group">
-                                            <label for="openai-max-completion-tokens"><span data-i18n="settingsBasic.maxCompletionTokens">最大输出 Token 数</span></label>
-                                            <input type="number" id="openai-max-completion-tokens" data-i18n="settingsBasic.maxCompletionTokensPlaceholder" data-i18n-attr="placeholder" placeholder="16384" min="1" step="256" />
-                                            <small style="color: var(--text-muted, #718096); font-size: 0.75rem;" data-i18n="settingsBasic.maxCompletionTokensHint">单次模型回复的输出上限，默认 16384</small>
-                                        </div>
-                                        <div class="form-group">
-                                            <label data-i18n="settingsBasic.openaiReasoningTitle">推理设置</label>
-                                            <small class="form-hint" data-i18n="settingsBasic.openaiReasoningHint">作为该 AI 通道的默认推理设置；对话页「会话设置」可覆盖。</small>
-                                            <div style="display: flex; flex-wrap: wrap; gap: 10px; margin-top: 8px; align-items: center;">
-                                                <label for="openai-reasoning-mode" style="font-size: 0.8125rem;" data-i18n="chat.reasoningModeLabel">模式</label>
-                                                <select id="openai-reasoning-mode" style="min-width: 140px; padding: 0.35rem 0.5rem; border-radius: 6px; border: 1px solid var(--border-color, #e2e8f0);">
-                                                    <option value="auto" data-i18n="chat.reasoningModeAuto">自动</option>
-                                                    <option value="on" data-i18n="chat.reasoningModeOn">开启</option>
-                                                    <option value="off" data-i18n="chat.reasoningModeOff">关闭</option>
-                                                </select>
-                                                <label for="openai-reasoning-effort" style="font-size: 0.8125rem;" data-i18n="chat.reasoningEffortLabel">强度</label>
-                                                <select id="openai-reasoning-effort" style="min-width: 140px; padding: 0.35rem 0.5rem; border-radius: 6px; border: 1px solid var(--border-color, #e2e8f0);">
-                                                    <option value="" data-i18n="chat.reasoningEffortUnset">不指定</option>
-                                                    <option value="low">low</option>
-                                                    <option value="medium">medium</option>
-                                                    <option value="high">high</option>
-                                                    <option value="xhigh">xhigh</option>
-                                                    <option value="max">max</option>
-                                                </select>
-                                                <label for="openai-reasoning-profile" style="font-size: 0.8125rem;" data-i18n="settingsBasic.openaiReasoningProfile">线路</label>
-                                                <select id="openai-reasoning-profile" style="min-width: 220px; padding: 0.35rem 0.5rem; border-radius: 6px; border: 1px solid var(--border-color, #e2e8f0);">
-                                                    <option value="auto">auto</option>
-                                                    <option value="deepseek_compat">deepseek_compat</option>
-                                                    <option value="openai_compat">openai_compat</option>
-                                                    <option value="output_config_effort">output_config_effort</option>
-                                                </select>
-                                            </div>
-                                            <label class="checkbox-label" style="margin-top: 8px;">
-                                                <input type="checkbox" id="openai-reasoning-allow-client" class="modern-checkbox" checked />
-                                                <span class="checkbox-custom"></span>
-                                                <span class="checkbox-text" data-i18n="settingsBasic.openaiReasoningAllowClient">允许对话页覆盖推理选项</span>
-                                            </label>
-                                        </div>
-                                        <div style="display: flex; align-items: center; gap: 8px; margin-top: 2px;">
-                                            <a href="javascript:void(0)" id="test-openai-btn" onclick="testOpenAIConnection()" style="font-size: 0.8125rem; color: var(--accent-color, #3182ce); text-decoration: none; cursor: pointer; user-select: none;" data-i18n="settingsBasic.testConnection">测试连接</a>
-                                            <span id="test-openai-result" style="font-size: 0.8125rem;"></span>
-                                        </div>
+                                                    <section class="ai-channel-form-section">
+                                                        <div class="ai-channel-form-section-head">
+                                                            <div>
+                                                                <h6 data-i18n="settingsBasic.aiChannelConnectionSection">连接信息</h6>
+                                                                <p data-i18n="settingsBasic.aiChannelConnectionHint">先确认服务商、地址、密钥和模型，测试连接会使用这些信息。</p>
+                                                            </div>
+                                                            <div class="ai-channel-section-actions">
+                                                                <button type="button" id="test-openai-btn" class="btn-secondary" onclick="testOpenAIConnection()" data-i18n="settingsBasic.testConnection">测试连接</button>
+                                                                <span id="test-openai-result" class="form-inline-result connection-test-result"></span>
+                                                            </div>
+                                                        </div>
+                                                        <div class="ai-channel-form-grid">
+                                                            <div class="form-group">
+                                                                <label for="ai-channel-name" data-i18n="settingsBasic.aiChannelName">通道名称</label>
+                                                                <input type="text" id="ai-channel-name" placeholder="Qwen Max" maxlength="24" />
+                                                            </div>
+                                                            <div class="form-group">
+                                                                <label for="openai-provider" data-i18n="settingsBasic.apiProvider">API 提供商</label>
+                                                                <select id="openai-provider">
+                                                                    <option value="openai_compatible" data-i18n="settingsBasic.providerOpenAI">OpenAI / 兼容 OpenAI 协议</option>
+                                                                    <option value="claude" data-i18n="settingsBasic.providerClaude">Claude (Anthropic Messages API)</option>
+                                                                </select>
+                                                            </div>
+                                                            <div class="form-group span-2">
+                                                                <label for="openai-base-url">Base URL <span class="required-mark">*</span></label>
+                                                                <input type="text" id="openai-base-url" data-i18n="settingsBasic.openaiBaseUrlPlaceholder" data-i18n-attr="placeholder" placeholder="https://api.openai.com/v1" required />
+                                                            </div>
+                                                            <div class="form-group span-2">
+                                                                <label for="openai-api-key">API Key <span class="required-mark">*</span></label>
+                                                                <input type="password" id="openai-api-key" data-i18n="settingsBasic.openaiApiKeyPlaceholder" data-i18n-attr="placeholder" placeholder="输入OpenAI API Key" required />
+                                                            </div>
+                                                            <div class="form-group span-2">
+                                                                <label for="openai-model"><span data-i18n="settingsBasic.model">模型</span> <span class="required-mark">*</span></label>
+                                                                <div class="model-pick-row">
+                                                                    <input type="text" id="openai-model" class="model-pick-input" data-i18n="settingsBasic.modelPlaceholder" data-i18n-attr="placeholder" placeholder="gpt-4" required />
+                                                                    <select id="openai-model-select" class="model-pick-native" style="display: none;" title="" aria-hidden="true" tabindex="-1">
+                                                                        <option value="" disabled data-i18n="settingsBasic.modelsListSelectPlaceholder">请选择模型</option>
+                                                                    </select>
+                                                                    <a href="javascript:void(0)" id="fetch-openai-models-btn" class="model-pick-fetch-link" onclick="fetchModelList('openai')" data-i18n="settingsBasic.fetchModels">获取列表</a>
+                                                                </div>
+                                                                <small id="fetch-openai-models-hint" class="form-hint" style="display: none;"></small>
+                                                                <span id="fetch-openai-models-result" class="form-inline-result"></span>
+                                                            </div>
+                                                        </div>
+                                                    </section>
+
+                                                    <section class="ai-channel-form-section">
+                                                        <div class="ai-channel-form-section-head">
+                                                            <div>
+                                                                <h6 data-i18n="settingsBasic.aiChannelLimitsSection">额度设置</h6>
+                                                                <p data-i18n="settingsBasic.aiChannelLimitsHint">Token 上限控制上下文窗口和单次输出。</p>
+                                                            </div>
+                                                        </div>
+                                                        <div class="ai-channel-form-grid">
+                                                            <div class="form-group">
+                                                                <label for="openai-max-total-tokens"><span data-i18n="settingsBasic.maxTotalTokens">最大上下文 Token 数</span></label>
+                                                                <input type="number" id="openai-max-total-tokens" data-i18n="settingsBasic.maxTotalTokensPlaceholder" data-i18n-attr="placeholder" placeholder="120000" min="1000" step="1000" />
+                                                                <small class="form-hint" data-i18n="settingsBasic.maxTotalTokensHint">内存压缩和攻击链构建共用此配置，默认 120000</small>
+                                                            </div>
+                                                            <div class="form-group">
+                                                                <label for="openai-max-completion-tokens"><span data-i18n="settingsBasic.maxCompletionTokens">最大输出 Token 数</span></label>
+                                                                <input type="number" id="openai-max-completion-tokens" data-i18n="settingsBasic.maxCompletionTokensPlaceholder" data-i18n-attr="placeholder" placeholder="16384" min="1" step="256" />
+                                                                <small class="form-hint" data-i18n="settingsBasic.maxCompletionTokensHint">单次模型回复的输出上限，默认 16384</small>
+                                                            </div>
+                                                        </div>
+                                                    </section>
+
+                                                    <details class="ai-channel-form-section ai-channel-advanced-section">
+                                                        <summary>
+                                                            <span>
+                                                                <strong data-i18n="settingsBasic.openaiReasoningTitle">推理设置</strong>
+                                                                <small data-i18n="settingsBasic.openaiReasoningHint">作为该 AI 通道的默认推理设置；对话页「会话设置」可覆盖。</small>
+                                                            </span>
+                                                        </summary>
+                                                        <div class="ai-channel-reasoning-grid">
+                                                            <div class="form-group">
+                                                                <label for="openai-reasoning-mode" data-i18n="chat.reasoningModeLabel">模式</label>
+                                                                <select id="openai-reasoning-mode">
+                                                                    <option value="auto" data-i18n="chat.reasoningModeAuto">自动</option>
+                                                                    <option value="on" data-i18n="chat.reasoningModeOn">开启</option>
+                                                                    <option value="off" data-i18n="chat.reasoningModeOff">关闭</option>
+                                                                </select>
+                                                            </div>
+                                                            <div class="form-group">
+                                                                <label for="openai-reasoning-effort" data-i18n="chat.reasoningEffortLabel">强度</label>
+                                                                <select id="openai-reasoning-effort">
+                                                                    <option value="" data-i18n="chat.reasoningEffortUnset">不指定</option>
+                                                                    <option value="low">low</option>
+                                                                    <option value="medium">medium</option>
+                                                                    <option value="high">high</option>
+                                                                    <option value="xhigh">xhigh</option>
+                                                                    <option value="max">max</option>
+                                                                </select>
+                                                            </div>
+                                                            <div class="form-group">
+                                                                <label for="openai-reasoning-profile" data-i18n="settingsBasic.openaiReasoningProfile">线路</label>
+                                                                <select id="openai-reasoning-profile">
+                                                                    <option value="auto">auto</option>
+                                                                    <option value="deepseek_compat">deepseek_compat</option>
+                                                                    <option value="openai_compat">openai_compat</option>
+                                                                    <option value="output_config_effort">output_config_effort</option>
+                                                                </select>
+                                                            </div>
+                                                        </div>
+                                                        <label class="checkbox-label ai-channel-reasoning-toggle">
+                                                            <input type="checkbox" id="openai-reasoning-allow-client" class="modern-checkbox" checked />
+                                                            <span class="checkbox-custom"></span>
+                                                            <span class="checkbox-text" data-i18n="settingsBasic.openaiReasoningAllowClient">允许对话页覆盖推理选项</span>
+                                                        </label>
+                                                    </details>
                                                 </div>
                                             </div>
                                         </div>