diff --git a/backend/alembic_migrations/versions/0037_merge_project_caf_into_description.py b/backend/alembic_migrations/versions/0037_merge_project_caf_into_description.py
index 327a603c..deaaa66a 100644
--- a/backend/alembic_migrations/versions/0037_merge_project_caf_into_description.py
+++ b/backend/alembic_migrations/versions/0037_merge_project_caf_into_description.py
@@ -18,6 +18,7 @@
 
 import sqlalchemy as sa
 from alembic import op
+from sqlalchemy import text
 
 # revision identifiers, used by Alembic.
 revision: str = "0037_merge_project_caf_into_description"
@@ -27,6 +28,20 @@
 
 
 def upgrade() -> None:
+    conn = op.get_bind()
+    result = conn.execute(
+        text(
+            "SELECT COUNT(*) FROM resume_projects"
+            " WHERE challenge != '' OR action != '' OR result != ''"
+        )
+    )
+    count = result.scalar() or 0
+    if count > 0:
+        raise RuntimeError(
+            f"resume_projects に challenge/action/result のデータが {count} 件残っています。"
+            "カラム削除前にデータを退避してください。"
+        )
+
     with op.batch_alter_table("resume_projects") as batch_op:
         batch_op.add_column(
             sa.Column("description", sa.Text(), nullable=False, server_default=""),
diff --git a/frontend/src/components/forms/CareerFormEditors/CareerExperienceEditor.tsx b/frontend/src/components/forms/CareerFormEditors/CareerExperienceEditor.tsx
index 3e2c6226..a24b41b9 100644
--- a/frontend/src/components/forms/CareerFormEditors/CareerExperienceEditor.tsx
+++ b/frontend/src/components/forms/CareerFormEditors/CareerExperienceEditor.tsx
@@ -81,8 +81,9 @@ export function CareerExperienceEditor({
           <label>
             {/* グローバル CSS で label { display: grid } のため、テキストと DirtyDot を span で
               束ねないと別々の行になる。span で 1 グリッド行に束ねることでラベル右側に並べる。 */}
-            <span>
+            <span className={shared.labelText}>
               会社名
+              <span className={shared.requiredBadge}>必須</span>
               <DirtyDot visible={Boolean(fieldDirty?.company)} />
             </span>
             <input
@@ -92,8 +93,9 @@ export function CareerExperienceEditor({
             />
           </label>
           <label>
-            <span>
+            <span className={shared.labelText}>
               事業内容
+              <span className={shared.requiredBadge}>必須</span>
               <DirtyDot visible={Boolean(fieldDirty?.business_description)} />
             </span>
             <input
@@ -109,8 +111,9 @@ export function CareerExperienceEditor({
 
         <div className={shared.inline}>
           <label>
-            <span>
+            <span className={shared.labelText}>
               開始
+              <span className={shared.requiredBadge}>必須</span>
               <DirtyDot visible={Boolean(fieldDirty?.start_date)} />
             </span>
             <input
@@ -136,8 +139,9 @@ export function CareerExperienceEditor({
           </label>
           {!exp.is_current && (
             <label>
-              <span>
+              <span className={shared.labelText}>
                 離職年月
+                <span className={shared.requiredBadge}>必須</span>
                 <DirtyDot visible={Boolean(fieldDirty?.end_date)} />
               </span>
               <input
@@ -164,6 +168,7 @@ export function CareerExperienceEditor({
               <input
                 type="number"
                 min="0"
+                step="1"
                 value={exp.employee_count}
                 onChange={(e) =>
                   onUpdateExperienceField(expIndex, "employee_count", e.target.value)
diff --git a/frontend/src/components/forms/ProjectModal.tsx b/frontend/src/components/forms/ProjectModal.tsx
index 1ce7bcc4..e25ab167 100644
--- a/frontend/src/components/forms/ProjectModal.tsx
+++ b/frontend/src/components/forms/ProjectModal.tsx
@@ -15,6 +15,7 @@ import { Combobox } from "./Combobox";
 import { MarkdownTextarea } from "./MarkdownTextarea";
 import { ResumePdfTracePanel } from "./ResumePdfTracePanel";
 import { DirtyDot } from "../ui/DirtyDot";
+import shared from "../../styles/shared.module.css";
 import styles from "./ProjectModal.module.css";
 
 type ProjectModalProps = {
@@ -126,7 +127,10 @@ export function ProjectModal({
               {local.periods.map((period, periodIndex) => (
                 <div key={`period-${periodIndex}`} className={styles.inline}>
                   <label>
-                    <span>開始</span>
+                    <span className={shared.labelText}>
+                      開始
+                      <span className={shared.requiredBadge}>必須</span>
+                    </span>
                     <input
                       type="month"
                       value={period.start_date}
@@ -147,7 +151,10 @@ export function ProjectModal({
                   </label>
                   {!period.is_current && (
                     <label>
-                      <span>終了</span>
+                      <span className={shared.labelText}>
+                        終了
+                        <span className={shared.requiredBadge}>必須</span>
+                      </span>
                       <input
                         type="month"
                         value={period.end_date}
diff --git a/frontend/src/components/forms/sections/CareerQualificationsSection.tsx b/frontend/src/components/forms/sections/CareerQualificationsSection.tsx
index d3bc1a1b..2925d722 100644
--- a/frontend/src/components/forms/sections/CareerQualificationsSection.tsx
+++ b/frontend/src/components/forms/sections/CareerQualificationsSection.tsx
@@ -89,8 +89,10 @@ export function CareerQualificationsSection({
                 <div key={`qualification-${index}`} className={shared.entry}>
                   <div className={shared.inline}>
                     <label>
-                      <span>
-                        資格名 ※プルダウンにないものはテキストで入力できます。
+                      <span className={shared.labelText}>
+                        資格名
+                        <span className={shared.requiredBadge}>必須</span>
+                        ※プルダウンにないものはテキストで入力できます。
                         <DirtyDot visible={Boolean(rowDirty?.fields.name)} />
                       </span>
                       <Combobox
@@ -102,8 +104,9 @@ export function CareerQualificationsSection({
                       />
                     </label>
                     <label>
-                      <span>
+                      <span className={shared.labelText}>
                         取得日
+                        <span className={shared.requiredBadge}>必須</span>
                         <DirtyDot visible={Boolean(rowDirty?.fields.acquired_date)} />
                       </span>
                       <input
diff --git a/frontend/src/hooks/career/usePdfPanelLayout.ts b/frontend/src/hooks/career/usePdfPanelLayout.ts
index 77ba6be2..035436b8 100644
--- a/frontend/src/hooks/career/usePdfPanelLayout.ts
+++ b/frontend/src/hooks/career/usePdfPanelLayout.ts
@@ -63,6 +63,8 @@ export function usePdfPanelLayout(
     return () => {
       window.removeEventListener("mousemove", onMove);
       window.removeEventListener("mouseup", onUp);
+      document.body.style.userSelect = "";
+      document.body.style.cursor = "";
     };
   }, [containerRef, minWidth, minFormWidth, reservedGap]);
 
diff --git a/frontend/src/hooks/career/useProjectFormDirty.test.ts b/frontend/src/hooks/career/useProjectFormDirty.test.ts
index 7474f4e2..e57b8e1f 100644
--- a/frontend/src/hooks/career/useProjectFormDirty.test.ts
+++ b/frontend/src/hooks/career/useProjectFormDirty.test.ts
@@ -94,4 +94,22 @@ describe("useProjectFormDirty", () => {
     const { result } = renderHook(() => useProjectFormDirty(local, null));
     expect(result.current.any).toBe(false);
   });
+
+  it("description を変更すると fields.description と any が true", () => {
+    const original = buildProject();
+    const local = buildProject({ description: "変更後の詳細" });
+    const { result } = renderHook(() => useProjectFormDirty(local, original));
+    expect(result.current.fields.description).toBe(true);
+    expect(result.current.any).toBe(true);
+    expect(result.current.fields.name).toBe(false);
+    expect(result.current.team).toBe(false);
+  });
+
+  it("description を元の値に戻すと fields.description と any が false", () => {
+    const original = buildProject();
+    const local = buildProject({ description: original.description });
+    const { result } = renderHook(() => useProjectFormDirty(local, original));
+    expect(result.current.fields.description).toBe(false);
+    expect(result.current.any).toBe(false);
+  });
 });
diff --git a/frontend/src/payloadBuilders.test.ts b/frontend/src/payloadBuilders.test.ts
index d3bc94cd..8f1698c6 100644
--- a/frontend/src/payloadBuilders.test.ts
+++ b/frontend/src/payloadBuilders.test.ts
@@ -235,6 +235,26 @@ describe("buildCareerPayload (projects/clients/team)", () => {
     ).toThrow(/プロジェクトの開始年月/);
   });
 
+  it("内容のある project に period が 1 件も無いならエラー", () => {
+    expect(() =>
+      buildCareerPayload(
+        baseState({
+          experiences: [
+            blankExperience({
+              clients: [
+                {
+                  name: "顧客A",
+                  has_client: true,
+                  projects: [blankProject({ name: "P", description: "詳細", periods: [] })],
+                },
+              ],
+            }),
+          ],
+        }),
+      ),
+    ).toThrow(/プロジェクトの開始年月/);
+  });
+
   it("project の period が is_current=false で終了年月が空ならエラー", () => {
     expect(() =>
       buildCareerPayload(
@@ -381,6 +401,27 @@ describe("buildCareerPayload (projects/clients/team)", () => {
       { category: "db", name: "PostgreSQL" },
     ]);
   });
+
+  it("project の name が空で description に内容があればプロジェクトはペイロードに含まれる", () => {
+    const payload = buildCareerPayload(
+      baseState({
+        experiences: [
+          blankExperience({
+            clients: [
+              {
+                name: "C",
+                has_client: true,
+                projects: [blankProject({ name: "", description: "開発の詳細" })],
+              },
+            ],
+          }),
+        ],
+      }),
+    );
+    const project = payload.experiences[0].clients[0].projects[0];
+    expect(project.name).toBe("");
+    expect(project.description).toBe("開発の詳細");
+  });
 });
 
 // ── qualifications の境界 ────────────────────────────────────
diff --git a/frontend/src/payloadBuilders.ts b/frontend/src/payloadBuilders.ts
index 6cd0e000..98389e57 100644
--- a/frontend/src/payloadBuilders.ts
+++ b/frontend/src/payloadBuilders.ts
@@ -175,6 +175,9 @@ export function buildCareerPayload(state: CareerFormState): CareerResumePayload
     for (const client of exp.clients) {
       for (const proj of client.projects) {
         // 内容のあるプロジェクトは periods が 1 件以上あり、各期間の開始年月が必須。
+        if (proj.periods.length === 0) {
+          throw new Error(VALIDATION_MESSAGES.PROJECT_START_DATE_REQUIRED);
+        }
         for (const period of proj.periods) {
           if (!period.start_date) {
             throw new Error(VALIDATION_MESSAGES.PROJECT_START_DATE_REQUIRED);