diff --git a/.gitignore b/.gitignore
index b5c87ff..e11d940 100644
--- a/.gitignore
+++ b/.gitignore
@@ -27,4 +27,5 @@ node_modules/
 
 
 # Local-only notes
+temp/
 POST_OVERVIEW.md
diff --git a/doc/agent-smoke-cases.md b/doc/agent-smoke-cases.md
index 7d90fb5..e213c3b 100644
--- a/doc/agent-smoke-cases.md
+++ b/doc/agent-smoke-cases.md
@@ -66,16 +66,20 @@ bash scripts/agent-smoke.sh --cdp-port 9222 --cases AGENT-CHROME-001,AGENT-CHROM
 范围：
 抽屉基础控件渲染
 
+状态：
+用例内会显式切到 `整页模式`
+
 步骤：
 
 1. 先执行 `AGENT-CHROME-001`
+2. 在 `选项` 中确认当前为 `整页模式`
 
 断言：
 
 1. `上一帖` 按钮存在
 2. `下一帖` 按钮存在
 3. `选项` 按钮存在
-4. `回复主题` 按钮存在
+4. `回复主题` 按钮存在但默认隐藏
 5. `新标签打开` 链接存在
 
 ### AGENT-CHROME-003：设置面板打开和关闭
@@ -273,7 +277,7 @@ bash scripts/agent-smoke.sh --cdp-port 9222 --cases AGENT-CHROME-001,AGENT-CHROM
 头部 `回复主题` 主入口 + 可选悬浮快捷入口
 
 状态：
-当前不在默认批量脚本中
+当前不在默认批量脚本中；用例内会显式切到 `智能预览`
 
 步骤：
 
@@ -310,6 +314,48 @@ bash scripts/agent-smoke.sh --cdp-port 9222 --cases AGENT-CHROME-001,AGENT-CHROM
 2. 文本按钮和链接都保持 `white-space: nowrap`
 3. 可见文本按钮的宽度应明显大于高度，避免被挤成竖排窄条
 
+### AGENT-CHROME-016：正文字号设置应即时生效
+
+范围：
+抽屉设置中的正文字号滑杆
+
+状态：
+当前不在默认批量脚本中；用例内会显式切到 `智能预览`
+
+步骤：
+
+1. 打开任一主题抽屉
+2. 打开 `选项`
+3. 读取第一条帖子正文 `.ld-post-body` 的计算字号
+4. 拖动 `正文字号` 滑杆到另一个档位
+
+断言：
+
+1. 滑杆右侧读数会同步更新成新的 `xxpx`
+2. `.ld-post-body` 的计算 `font-size` 会立即更新成对应像素值
+3. 若当前正文里存在 `pre` / `code`，其字号也会同步变化，并保持比正文小 `1px`
+
+### AGENT-CHROME-017：整页模式下正文字号设置应禁用
+
+范围：
+默认整页模式下的正文字号控件可用性
+
+状态：
+当前不在默认批量脚本中；用例内会显式切到 `整页模式`
+
+步骤：
+
+1. 打开任一主题抽屉
+2. 打开 `选项`
+3. 切到 `整页模式`
+4. 读取 `正文字号` 设置项状态
+
+断言：
+
+1. `正文字号` 设置项显示为禁用态
+2. 对应滑杆 `disabled=true`
+3. 提示文案明确说明该设置仅在 `智能预览` 下生效
+
 ## 3. 记录格式
 
 执行完用例后，建议按下面格式留证据：
diff --git a/scripts/agent-smoke.sh b/scripts/agent-smoke.sh
index 441aae2..1c3e34b 100755
--- a/scripts/agent-smoke.sh
+++ b/scripts/agent-smoke.sh
@@ -21,6 +21,8 @@ ALL_CASES=(
   "AGENT-CHROME-013"
   "AGENT-CHROME-014"
   "AGENT-CHROME-015"
+  "AGENT-CHROME-016"
+  "AGENT-CHROME-017"
 )
 
 CASES=("${DEFAULT_CASES[@]}")
@@ -469,22 +471,37 @@ set_setting_value() {
 (() => {
   const key = $key_json;
   const value = $value_json;
-  const select = document.querySelector(\`#ld-drawer-settings [data-setting="\${key}"]\`);
-  if (!(select instanceof HTMLSelectElement)) {
+  const control = document.querySelector(\`#ld-drawer-settings [data-setting="\${key}"]\`);
+  if (!(control instanceof HTMLSelectElement) && !(control instanceof HTMLInputElement)) {
     return { ok: false, reason: "setting-not-found", key };
   }
 
-  const hasOption = Array.from(select.options).some((option) => option.value === value);
-  if (!hasOption) {
-    return { ok: false, reason: "option-not-found", key, value };
+  if (control instanceof HTMLSelectElement) {
+    const hasOption = Array.from(control.options).some((option) => option.value === value);
+    if (!hasOption) {
+      return { ok: false, reason: "option-not-found", key, value };
+    }
+
+    if (control.value === value) {
+      return { ok: true, changed: false, key, value };
+    }
+
+    control.value = value;
+    control.dispatchEvent(new Event("change", { bubbles: true }));
+    return { ok: true, changed: true, key, value };
+  }
+
+  if (control.type !== "range") {
+    return { ok: false, reason: "unsupported-input-type", key, inputType: control.type || "text" };
   }
 
-  if (select.value === value) {
+  if (control.value === value) {
     return { ok: true, changed: false, key, value };
   }
 
-  select.value = value;
-  select.dispatchEvent(new Event("change", { bubbles: true }));
+  control.value = value;
+  control.dispatchEvent(new Event("input", { bubbles: true }));
+  control.dispatchEvent(new Event("change", { bubbles: true }));
   return { ok: true, changed: true, key, value };
 })()
 EOF
@@ -622,6 +639,35 @@ EOF
   ab_eval "$script"
 }
 
+post_body_font_state() {
+  local script
+  script=$(cat <<'EOF'
+(() => {
+  const body = document.querySelector("#ld-drawer-root .ld-post-body");
+  const field = document.querySelector('#ld-drawer-settings [data-setting-group="postBodyFontSize"]');
+  const control = document.querySelector('#ld-drawer-settings [data-setting="postBodyFontSize"]');
+  const value = document.querySelector('#ld-drawer-settings [data-setting-value="postBodyFontSize"]');
+  const hint = document.querySelector('#ld-drawer-settings [data-setting-hint="postBodyFontSize"]');
+  const code = document.querySelector("#ld-drawer-root .ld-post-body pre, #ld-drawer-root .ld-post-body code");
+  return {
+    pageOpen: document.body.classList.contains("ld-drawer-page-open"),
+    bodyExists: body instanceof HTMLElement,
+    bodyFontSize: body ? Math.round(parseFloat(getComputedStyle(body).fontSize) || 0) : null,
+    codeExists: code instanceof HTMLElement,
+    codeFontSize: code ? Math.round(parseFloat(getComputedStyle(code).fontSize) || 0) : null,
+    fieldDisabled: field?.classList.contains("is-disabled") || false,
+    fieldAriaDisabled: field?.getAttribute("aria-disabled") || null,
+    controlDisabled: control?.disabled || false,
+    controlValue: control?.value || null,
+    valueText: value?.textContent?.trim() || null,
+    hintText: hint?.textContent?.trim() || null
+  };
+})()
+EOF
+)
+  ab_eval "$script"
+}
+
 click_reply_trigger() {
   local target=$1
   local selector_json script
@@ -734,22 +780,39 @@ run_001() {
 
 run_002() {
   local case_id="AGENT-CHROME-002"
-  local state
+  local original_settings original_preview preview_result state
   open_topic_by_index 0 >/dev/null || {
     record_fail "$case_id" "无法打开抽屉"
     return 0
   }
+
+  original_settings=$(settings_values)
+  original_preview=$(echo "$original_settings" | jq -r '.previewMode // empty')
+  if [ -z "$original_preview" ]; then
+    record_fail "$case_id" "无法读取当前预览模式"
+    return 0
+  fi
+
+  preview_result=$(set_setting_value previewMode iframe)
+  if [ "$(echo "$preview_result" | jq -r '.ok')" != "true" ]; then
+    record_fail "$case_id" "无法切到整页模式: $preview_result"
+    return 0
+  fi
+  ab wait 1200 >/dev/null
+  ensure_settings_closed
   state=$(drawer_state)
 
+  set_setting_value previewMode "$original_preview" >/dev/null || true
+
   if [ "$(echo "$state" | jq -r '.prevText // empty')" = "上一帖" ] \
     && [ "$(echo "$state" | jq -r '.nextText // empty')" = "下一帖" ] \
     && [ "$(echo "$state" | jq -r '.settingsText // empty')" = "选项" ] \
     && [ "$(echo "$state" | jq -r '.replyText // empty')" = "回复主题" ] \
-    && [ "$(echo "$state" | jq -r '.replyHidden')" = "false" ] \
+    && [ "$(echo "$state" | jq -r '.replyHidden')" = "true" ] \
     && [ "$(echo "$state" | jq -r '.newTabText // empty')" = "新标签打开" ]; then
-    record_pass "$case_id" "toolbar ready"
+    record_pass "$case_id" "toolbar ready in iframe mode"
   else
-    record_fail "$case_id" "toolbar incomplete"
+    record_fail "$case_id" "toolbar incomplete: $(echo "$state" | jq -c '{prevText, nextText, settingsText, replyText, replyHidden, newTabText}')"
   fi
 }
 
@@ -1130,7 +1193,7 @@ run_013() {
 
 run_014() {
   local case_id="AGENT-CHROME-014"
-  local original_settings original_floating off_result off_state on_result on_state settings_open_state click_result panel_state
+  local original_settings original_floating original_preview preview_result off_result off_state on_result on_state settings_open_state click_result panel_state
   local passed=0
   local detail=""
 
@@ -1141,13 +1204,22 @@ run_014() {
 
   original_settings=$(settings_values)
   original_floating=$(echo "$original_settings" | jq -r '.floatingReplyButton // empty')
-  if [ -z "$original_floating" ]; then
-    record_fail "$case_id" "无法读取悬浮回复入口设置"
+  original_preview=$(echo "$original_settings" | jq -r '.previewMode // empty')
+  if [ -z "$original_floating" ] || [ -z "$original_preview" ]; then
+    record_fail "$case_id" "无法读取当前设置"
     return 0
   fi
 
+  preview_result=$(set_setting_value previewMode smart)
+  if [ "$(echo "$preview_result" | jq -r '.ok')" != "true" ]; then
+    record_fail "$case_id" "无法切到智能预览: $preview_result"
+    return 0
+  fi
+  ab wait 1200 >/dev/null
+
   off_result=$(set_setting_value floatingReplyButton off)
   if [ "$(echo "$off_result" | jq -r '.ok')" != "true" ]; then
+    set_setting_value previewMode "$original_preview" >/dev/null || true
     record_fail "$case_id" "无法关闭悬浮回复入口: $off_result"
     return 0
   fi
@@ -1175,6 +1247,7 @@ run_014() {
   close_reply_panel_if_open >/dev/null || true
   ab wait 400 >/dev/null
   set_setting_value floatingReplyButton "$original_floating" >/dev/null || true
+  set_setting_value previewMode "$original_preview" >/dev/null || true
   ab wait 800 >/dev/null
   ensure_settings_closed
 
@@ -1230,6 +1303,107 @@ run_015() {
   fi
 }
 
+run_016() {
+  local case_id="AGENT-CHROME-016"
+  local original_settings original_value original_preview preview_result target_value
+  local before set_result after
+
+  open_topic_by_index 0 >/dev/null || {
+    record_fail "$case_id" "无法打开抽屉"
+    return 0
+  }
+
+  original_settings=$(settings_values)
+  original_value=$(echo "$original_settings" | jq -r '.postBodyFontSize // empty')
+  original_preview=$(echo "$original_settings" | jq -r '.previewMode // empty')
+  if [ -z "$original_value" ] || [ -z "$original_preview" ]; then
+    record_fail "$case_id" "无法读取当前设置"
+    return 0
+  fi
+
+  preview_result=$(set_setting_value previewMode smart)
+  if [ "$(echo "$preview_result" | jq -r '.ok')" != "true" ]; then
+    record_fail "$case_id" "无法切到智能预览: $preview_result"
+    return 0
+  fi
+  ab wait 1200 >/dev/null
+  ensure_settings_open
+  before=$(post_body_font_state)
+  target_value=18
+  if [ "$original_value" = "18" ]; then
+    target_value=13
+  fi
+
+  set_result=$(set_setting_value postBodyFontSize "$target_value")
+  if [ "$(echo "$set_result" | jq -r '.ok')" != "true" ]; then
+    ensure_settings_closed
+    record_fail "$case_id" "无法设置正文字号: $set_result"
+    return 0
+  fi
+
+  ab wait 200 >/dev/null
+  after=$(post_body_font_state)
+
+  set_setting_value postBodyFontSize "$original_value" >/dev/null || true
+  set_setting_value previewMode "$original_preview" >/dev/null || true
+  ab wait 200 >/dev/null
+  ensure_settings_closed
+
+  if [ "$(echo "$before" | jq -r '.pageOpen')" = "true" ] \
+    && [ "$(echo "$before" | jq -r '.bodyExists')" = "true" ] \
+    && [ "$(echo "$after" | jq -r '.bodyExists')" = "true" ] \
+    && [ "$(echo "$after" | jq -r '.controlValue // empty')" = "$target_value" ] \
+    && [ "$(echo "$after" | jq -r '.valueText // empty')" = "${target_value}px" ] \
+    && [ "$(echo "$after" | jq -r '.bodyFontSize')" = "$target_value" ] \
+    && { [ "$(echo "$after" | jq -r '.codeExists')" != "true" ] || [ "$(echo "$after" | jq -r '.codeFontSize')" = "$((target_value - 1))" ]; } \
+    && [ "$(echo "$before" | jq -r '.bodyFontSize')" != "$(echo "$after" | jq -r '.bodyFontSize')" ]; then
+    record_pass "$case_id" "before=$(echo "$before" | jq -c '{bodyFontSize, codeExists, codeFontSize, controlValue, valueText}') after=$(echo "$after" | jq -c '{bodyFontSize, codeExists, codeFontSize, controlValue, valueText}')"
+  else
+    record_fail "$case_id" "before=$(echo "$before" | jq -c '{pageOpen, bodyExists, bodyFontSize, codeExists, codeFontSize, controlValue, valueText}') after=$(echo "$after" | jq -c '{pageOpen, bodyExists, bodyFontSize, codeExists, codeFontSize, controlValue, valueText}') target=$target_value"
+  fi
+}
+
+run_017() {
+  local case_id="AGENT-CHROME-017"
+  local original_settings original_preview preview_result state
+
+  open_topic_by_index 0 >/dev/null || {
+    record_fail "$case_id" "无法打开抽屉"
+    return 0
+  }
+
+  original_settings=$(settings_values)
+  original_preview=$(echo "$original_settings" | jq -r '.previewMode // empty')
+  if [ -z "$original_preview" ]; then
+    record_fail "$case_id" "无法读取当前预览模式"
+    return 0
+  fi
+
+  preview_result=$(set_setting_value previewMode iframe)
+  if [ "$(echo "$preview_result" | jq -r '.ok')" != "true" ]; then
+    record_fail "$case_id" "无法切到整页模式: $preview_result"
+    return 0
+  fi
+
+  ab wait 1200 >/dev/null
+  ensure_settings_open
+  state=$(post_body_font_state)
+
+  set_setting_value previewMode "$original_preview" >/dev/null || true
+  ab wait 200 >/dev/null
+  ensure_settings_closed
+
+  if [ "$(echo "$state" | jq -r '.pageOpen')" = "true" ] \
+    && [ "$(echo "$state" | jq -r '.fieldDisabled')" = "true" ] \
+    && [ "$(echo "$state" | jq -r '.fieldAriaDisabled // empty')" = "true" ] \
+    && [ "$(echo "$state" | jq -r '.controlDisabled')" = "true" ] \
+    && echo "$state" | jq -e '.hintText | test("仅智能预览可用")' >/dev/null; then
+    record_pass "$case_id" "state=$(echo "$state" | jq -c '{fieldDisabled, fieldAriaDisabled, controlDisabled, valueText, hintText}')"
+  else
+    record_fail "$case_id" "state=$(echo "$state" | jq -c '{pageOpen, fieldDisabled, fieldAriaDisabled, controlDisabled, controlValue, valueText, hintText}')"
+  fi
+}
+
 run_case() {
   local case_id=$1
   case "$case_id" in
@@ -1245,6 +1419,8 @@ run_case() {
     AGENT-CHROME-013) run_013 ;;
     AGENT-CHROME-014) run_014 ;;
     AGENT-CHROME-015) run_015 ;;
+    AGENT-CHROME-016) run_016 ;;
+    AGENT-CHROME-017) run_017 ;;
     *)
       record_fail "$case_id" "未知用例 ID"
       ;;
diff --git a/src/content.css b/src/content.css
index 742ec58..30e05fa 100644
--- a/src/content.css
+++ b/src/content.css
@@ -1,5 +1,6 @@
 :root {
   --ld-drawer-width: clamp(360px, 42vw, 920px);
+  --ld-post-body-font-size: 15px;
   --ld-image-preview-scale: 1;
   --ld-topic-tracker-left: 50vw;
   --ld-topic-tracker-top: 112px;
@@ -350,11 +351,28 @@ body.ld-drawer-page-open #ld-drawer-root {
   gap: 6px;
 }
 
+#ld-drawer-root .ld-setting-field.is-disabled {
+  opacity: 0.58;
+}
+
+#ld-drawer-root .ld-setting-row {
+  display: flex;
+  align-items: center;
+  justify-content: space-between;
+  gap: 10px;
+}
+
 #ld-drawer-root .ld-setting-label {
   font-size: 12px;
   color: var(--primary-medium, rgba(15, 23, 42, 0.64));
 }
 
+#ld-drawer-root .ld-setting-value {
+  color: var(--primary-medium, rgba(15, 23, 42, 0.72));
+  font-size: 12px;
+  font-variant-numeric: tabular-nums;
+}
+
 #ld-drawer-root .ld-setting-hint {
   font-size: 11px;
   color: var(--primary-medium, rgba(15, 23, 42, 0.56));
@@ -371,6 +389,23 @@ body.ld-drawer-page-open #ld-drawer-root {
   padding: 10px 12px;
 }
 
+#ld-drawer-root .ld-setting-range {
+  width: 100%;
+  margin: 0;
+  accent-color: var(--tertiary, #3b82f6);
+  cursor: pointer;
+}
+
+#ld-drawer-root .ld-setting-field.is-disabled .ld-setting-range {
+  cursor: not-allowed;
+}
+
+#ld-drawer-root .ld-setting-range:focus-visible {
+  outline: 2px solid color-mix(in srgb, var(--tertiary, #3b82f6) 24%, transparent);
+  outline-offset: 3px;
+  border-radius: 999px;
+}
+
 #ld-drawer-root .ld-settings-reset {
   align-self: end;
   justify-self: end;
@@ -707,7 +742,7 @@ body.ld-drawer-page-open #ld-drawer-root {
 #ld-drawer-root .ld-post-body {
   padding: 16px;
   line-height: 1.72;
-  font-size: 14px;
+  font-size: var(--ld-post-body-font-size, 14px);
 }
 
 #ld-drawer-root .ld-post-actions {
@@ -790,7 +825,7 @@ body.ld-drawer-page-open #ld-drawer-root {
 
 #ld-drawer-root .ld-post-body pre,
 #ld-drawer-root .ld-post-body code {
-  font-size: 13px;
+  font-size: max(12px, calc(var(--ld-post-body-font-size, 14px) - 1px));
 }
 
 #ld-drawer-root .ld-post-body pre {
diff --git a/src/content.js b/src/content.js
index f406477..2b9384e 100644
--- a/src/content.js
+++ b/src/content.js
@@ -10,19 +10,22 @@
   const IMAGE_PREVIEW_SCALE_MIN = 1;
   const IMAGE_PREVIEW_SCALE_MAX = 4;
   const IMAGE_PREVIEW_SCALE_STEP = 0.2;
+  const POST_BODY_FONT_SIZE_MIN = 13;
+  const POST_BODY_FONT_SIZE_MAX = 18;
   const REPLY_UPLOAD_MARKER = "\u2063";
   const POST_ACTION_TYPE_IDS = {
     like: 2
   };
   const DEFAULT_SETTINGS = {
-    previewMode: "smart",
+    previewMode: "iframe",
     postMode: "all",
+    postBodyFontSize: 15,
     authorFilter: "all",
     replyOrder: "default",
     floatingReplyButton: "off",
-    drawerWidth: "medium",
+    drawerWidth: "narrow",
     drawerWidthCustom: 720,
-    drawerMode: "push"
+    drawerMode: "overlay"
   };
   const DRAWER_WIDTHS = {
     narrow: "clamp(320px, 34vw, 680px)",
@@ -106,6 +109,10 @@
     openInTab: null,
     settingsPanel: null,
     settingsCard: null,
+    postBodyFontSizeField: null,
+    postBodyFontSizeControl: null,
+    postBodyFontSizeValue: null,
+    postBodyFontSizeHint: null,
     settingsCloseButton: null,
     settingsToggle: null,
     latestRepliesRefreshButton: null,
@@ -206,6 +213,21 @@
                 <option value="first">仅首帖</option>
               </select>
             </label>
+            <label class="ld-setting-field" data-setting-group="postBodyFontSize">
+              <div class="ld-setting-row">
+                <span class="ld-setting-label">正文字号</span>
+                <span class="ld-setting-value" data-setting-value="postBodyFontSize">15px</span>
+              </div>
+              <input
+                class="ld-setting-range"
+                type="range"
+                min="${POST_BODY_FONT_SIZE_MIN}"
+                max="${POST_BODY_FONT_SIZE_MAX}"
+                step="1"
+                data-setting="postBodyFontSize"
+              />
+              <span class="ld-setting-hint" data-setting-hint="postBodyFontSize">只调整帖子正文和代码字号，不影响标题和按钮</span>
+            </label>
             <label class="ld-setting-field">
               <span class="ld-setting-label">作者过滤</span>
               <select class="ld-setting-control" data-setting="authorFilter">
@@ -305,6 +327,10 @@
     state.openInTab = root.querySelector(".ld-drawer-link");
     state.settingsPanel = root.querySelector(".ld-drawer-settings");
     state.settingsCard = root.querySelector(".ld-drawer-settings-card");
+    state.postBodyFontSizeField = root.querySelector('[data-setting-group="postBodyFontSize"]');
+    state.postBodyFontSizeControl = root.querySelector('[data-setting="postBodyFontSize"]');
+    state.postBodyFontSizeValue = root.querySelector('[data-setting-value="postBodyFontSize"]');
+    state.postBodyFontSizeHint = root.querySelector('[data-setting-hint="postBodyFontSize"]');
     state.settingsCloseButton = root.querySelector(".ld-settings-close");
     state.settingsToggle = root.querySelector(".ld-drawer-settings-toggle");
     state.latestRepliesRefreshButton = root.querySelector(".ld-drawer-refresh");
@@ -328,12 +354,14 @@
     root.addEventListener("wheel", handleDrawerRootWheel, { passive: false });
     state.drawerBody.addEventListener("scroll", handleDrawerBodyScroll, { passive: true });
     state.settingsPanel.addEventListener("click", handleSettingsPanelClick);
+    state.settingsPanel.addEventListener("input", handleSettingsInput);
     state.settingsPanel.addEventListener("change", handleSettingsChange);
     state.settingsCloseButton.addEventListener("click", () => setSettingsPanelOpen(false));
     state.settingsPanel.querySelector(".ld-settings-reset").addEventListener("click", resetSettings);
     state.resizeHandle.addEventListener("pointerdown", startDrawerResize);
 
     syncSettingsUI();
+    applyPostBodyFontSize();
     applyDrawerWidth();
     syncNavigationState();
     syncLatestRepliesRefreshUI();
@@ -816,18 +844,17 @@
     state.isLoadingMorePosts = false;
     state.loadMoreError = "";
 
+    if (state.abortController) {
+      state.abortController.abort();
+      state.abortController = null;
+    }
+
     if (state.settings.previewMode === "iframe") {
-      if (!state.currentViewTracked) {
-        ensureTrackedTopicVisit(topicUrl, topicIdHint).catch(() => {});
-      }
       renderIframeFallback(topicUrl, fallbackTitle, null, true);
+      syncLatestRepliesRefreshUI();
       return;
     }
 
-    if (state.abortController) {
-      state.abortController.abort();
-    }
-
     if (!state.currentViewTracked) {
       state.currentTrackRequest = null;
       state.currentTrackRequestKey = "";
@@ -2315,17 +2342,15 @@
       if (state.abortController) {
         state.abortController.abort();
         state.abortController = null;
-        if (!state.currentViewTracked) {
-          state.currentTrackRequest = null;
-          state.currentTrackRequestKey = "";
-        }
       }
 
       if (!state.currentViewTracked) {
-        ensureTrackedTopicVisit(state.currentUrl, state.currentTopicIdHint).catch(() => {});
+        state.currentTrackRequest = null;
+        state.currentTrackRequestKey = "";
       }
 
       renderIframeFallback(state.currentUrl, state.currentFallbackTitle, null, true);
+      syncLatestRepliesRefreshUI();
       return;
     }
 
@@ -3409,6 +3434,7 @@
         settings.floatingReplyButton = DEFAULT_SETTINGS.floatingReplyButton;
       }
 
+      settings.postBodyFontSize = clampPostBodyFontSize(settings.postBodyFontSize);
       settings.drawerWidthCustom = clampDrawerWidth(settings.drawerWidthCustom);
       return settings;
     } catch {
@@ -3504,9 +3530,37 @@
     for (const control of state.settingsPanel.querySelectorAll("[data-setting]")) {
       const key = control.dataset.setting;
       if (key && key in state.settings) {
-        control.value = state.settings[key];
+        control.value = String(state.settings[key]);
       }
     }
+
+    syncPostBodyFontSizeValue();
+    syncPostBodyFontSizeControlState();
+  }
+
+  function syncPostBodyFontSizeValue() {
+    if (state.postBodyFontSizeValue) {
+      state.postBodyFontSizeValue.textContent = `${clampPostBodyFontSize(state.settings.postBodyFontSize)}px`;
+    }
+  }
+
+  function syncPostBodyFontSizeControlState() {
+    const isSmartPreview = state.settings.previewMode === "smart";
+
+    if (state.postBodyFontSizeField) {
+      state.postBodyFontSizeField.classList.toggle("is-disabled", !isSmartPreview);
+      state.postBodyFontSizeField.setAttribute("aria-disabled", String(!isSmartPreview));
+    }
+
+    if (state.postBodyFontSizeControl) {
+      state.postBodyFontSizeControl.disabled = !isSmartPreview;
+    }
+
+    if (state.postBodyFontSizeHint) {
+      state.postBodyFontSizeHint.textContent = isSmartPreview
+        ? "只调整帖子正文和代码字号，不影响标题和按钮"
+        : "仅智能预览可用；当前整页模式下不会改变 iframe 里的字号。";
+    }
   }
 
   function toggleSettingsPanel() {
@@ -3526,6 +3580,7 @@
 
     if (isOpen) {
       setReplyPanelOpen(false);
+      syncSettingsUI();
       updateSettingsPopoverPosition();
       queueMicrotask(() => state.settingsCard?.querySelector(".ld-setting-control")?.focus());
     }
@@ -3535,9 +3590,25 @@
     syncReplyUI();
   }
 
+  function handleSettingsInput(event) {
+    const target = event.target;
+    if (!(target instanceof HTMLInputElement) || target.type !== "range") {
+      return;
+    }
+
+    const key = target.dataset.setting;
+    if (key !== "postBodyFontSize") {
+      return;
+    }
+
+    state.settings.postBodyFontSize = clampPostBodyFontSize(target.value);
+    target.value = String(state.settings.postBodyFontSize);
+    applyPostBodyFontSize();
+  }
+
   function handleSettingsChange(event) {
     const target = event.target;
-    if (!(target instanceof HTMLSelectElement)) {
+    if (!(target instanceof HTMLSelectElement) && !(target instanceof HTMLInputElement)) {
       return;
     }
 
@@ -3546,9 +3617,17 @@
       return;
     }
 
-    state.settings[key] = target.value;
+    state.settings[key] = key === "postBodyFontSize"
+      ? clampPostBodyFontSize(target.value)
+      : target.value;
+    target.value = String(state.settings[key]);
     saveSettings();
 
+    if (key === "postBodyFontSize") {
+      applyPostBodyFontSize();
+      return;
+    }
+
     if (key === "drawerWidth") {
       applyDrawerWidth();
       syncSettingsUI();
@@ -3576,6 +3655,7 @@
     state.settings = { ...DEFAULT_SETTINGS };
     syncSettingsUI();
     saveSettings();
+    applyPostBodyFontSize();
     applyDrawerWidth();
     applyDrawerMode();
     syncReplyUI();
@@ -3597,6 +3677,14 @@
     scheduleTopicTrackerPositionSync();
   }
 
+  function applyPostBodyFontSize() {
+    document.documentElement.style.setProperty(
+      "--ld-post-body-font-size",
+      `${clampPostBodyFontSize(state.settings.postBodyFontSize)}px`
+    );
+    syncPostBodyFontSizeValue();
+  }
+
   function applyDrawerMode() {
     const isOverlay = state.settings.drawerMode === "overlay";
     document.body.classList.toggle("ld-drawer-mode-overlay", isOverlay);
@@ -3613,6 +3701,16 @@
     return Math.min(Math.max(Math.round(numeric), 320), maxWidth);
   }
 
+  function clampPostBodyFontSize(value) {
+    const numeric = Number(value);
+
+    if (!Number.isFinite(numeric)) {
+      return DEFAULT_SETTINGS.postBodyFontSize;
+    }
+
+    return Math.min(Math.max(Math.round(numeric), POST_BODY_FONT_SIZE_MIN), POST_BODY_FONT_SIZE_MAX);
+  }
+
   function startDrawerResize(event) {
     if (event.button !== 0 || window.innerWidth <= 720) {
       return;