diff --git a/client/src/pages/JoinPage.module.css b/client/src/pages/JoinPage.module.css
new file mode 100644
index 0000000..270b95f
--- /dev/null
+++ b/client/src/pages/JoinPage.module.css
@@ -0,0 +1,84 @@
+.page {
+  display: flex;
+  justify-content: center;
+  align-items: center;
+  min-height: 60vh;
+}
+
+.card {
+  background: var(--card-bg);
+  border: 1px solid var(--border);
+  border-radius: 8px;
+  padding: 2rem;
+  width: 100%;
+  max-width: 380px;
+}
+
+.title {
+  font-size: 1.4rem;
+  font-weight: 700;
+  margin: 0 0 1.5rem;
+  color: var(--accent);
+}
+
+.field {
+  display: flex;
+  flex-direction: column;
+  gap: 0.4rem;
+  margin-bottom: 1rem;
+}
+
+.label {
+  font-size: 0.85rem;
+  color: var(--text-muted, #aaa);
+}
+
+.input {
+  background: var(--input-bg, #1a1a1a);
+  border: 1px solid var(--border);
+  border-radius: 4px;
+  color: var(--text);
+  font-size: 0.95rem;
+  padding: 0.5rem 0.75rem;
+}
+
+.input:focus {
+  outline: none;
+  border-color: var(--accent);
+}
+
+.error {
+  color: #e55;
+  font-size: 0.85rem;
+  margin-bottom: 0.75rem;
+}
+
+.btn {
+  width: 100%;
+  padding: 0.6rem;
+  background: var(--accent);
+  color: #fff;
+  border: none;
+  border-radius: 4px;
+  font-size: 1rem;
+  font-weight: 600;
+  cursor: pointer;
+  margin-top: 0.5rem;
+}
+
+.btn:disabled {
+  opacity: 0.6;
+  cursor: not-allowed;
+}
+
+.link {
+  display: block;
+  text-align: center;
+  margin-top: 1rem;
+  font-size: 0.85rem;
+  color: var(--text-muted, #aaa);
+}
+
+.link a {
+  color: var(--accent);
+}
diff --git a/client/src/pages/JoinPage.tsx b/client/src/pages/JoinPage.tsx
index 2a684e1..8a03b7e 100644
--- a/client/src/pages/JoinPage.tsx
+++ b/client/src/pages/JoinPage.tsx
@@ -1,3 +1,37 @@
+import { useEffect, useState } from "react";
+import { useParams, useNavigate } from "react-router-dom";
+import { joinCampaign } from "../api";
+import styles from "./JoinPage.module.css";
+
 export default function JoinPage() {
-  return <div>Join</div>;
+  const { token } = useParams<{ token: string }>();
+  const navigate = useNavigate();
+  const [status, setStatus] = useState<"joining" | "error">("joining");
+  const [error, setError] = useState("");
+
+  useEffect(() => {
+    if (!token) return;
+    joinCampaign(token)
+      .then(({ campaignId }) => {
+        navigate(`/campaign/${campaignId}`);
+      })
+      .catch((err) => {
+        setStatus("error");
+        setError(err instanceof Error ? err.message : "Invalid invite link");
+      });
+  }, [token, navigate]);
+
+  return (
+    <div className={styles.page}>
+      <div className={styles.card}>
+        {status === "joining" && <div className={styles.title}>Joining campaign…</div>}
+        {status === "error" && (
+          <>
+            <div className={styles.title}>Invalid Invite</div>
+            <div className={styles.error}>{error}</div>
+          </>
+        )}
+      </div>
+    </div>
+  );
 }
diff --git a/client/src/pages/LoginPage.module.css b/client/src/pages/LoginPage.module.css
new file mode 100644
index 0000000..270b95f
--- /dev/null
+++ b/client/src/pages/LoginPage.module.css
@@ -0,0 +1,84 @@
+.page {
+  display: flex;
+  justify-content: center;
+  align-items: center;
+  min-height: 60vh;
+}
+
+.card {
+  background: var(--card-bg);
+  border: 1px solid var(--border);
+  border-radius: 8px;
+  padding: 2rem;
+  width: 100%;
+  max-width: 380px;
+}
+
+.title {
+  font-size: 1.4rem;
+  font-weight: 700;
+  margin: 0 0 1.5rem;
+  color: var(--accent);
+}
+
+.field {
+  display: flex;
+  flex-direction: column;
+  gap: 0.4rem;
+  margin-bottom: 1rem;
+}
+
+.label {
+  font-size: 0.85rem;
+  color: var(--text-muted, #aaa);
+}
+
+.input {
+  background: var(--input-bg, #1a1a1a);
+  border: 1px solid var(--border);
+  border-radius: 4px;
+  color: var(--text);
+  font-size: 0.95rem;
+  padding: 0.5rem 0.75rem;
+}
+
+.input:focus {
+  outline: none;
+  border-color: var(--accent);
+}
+
+.error {
+  color: #e55;
+  font-size: 0.85rem;
+  margin-bottom: 0.75rem;
+}
+
+.btn {
+  width: 100%;
+  padding: 0.6rem;
+  background: var(--accent);
+  color: #fff;
+  border: none;
+  border-radius: 4px;
+  font-size: 1rem;
+  font-weight: 600;
+  cursor: pointer;
+  margin-top: 0.5rem;
+}
+
+.btn:disabled {
+  opacity: 0.6;
+  cursor: not-allowed;
+}
+
+.link {
+  display: block;
+  text-align: center;
+  margin-top: 1rem;
+  font-size: 0.85rem;
+  color: var(--text-muted, #aaa);
+}
+
+.link a {
+  color: var(--accent);
+}
diff --git a/client/src/pages/LoginPage.tsx b/client/src/pages/LoginPage.tsx
index ba5b453..fe361e7 100644
--- a/client/src/pages/LoginPage.tsx
+++ b/client/src/pages/LoginPage.tsx
@@ -1,3 +1,67 @@
+import { useState } from "react";
+import { useNavigate, Link } from "react-router-dom";
+import { login } from "../api";
+import { useAuth } from "../context/AuthContext";
+import styles from "./LoginPage.module.css";
+
 export default function LoginPage() {
-  return <div>Login</div>;
+  const { setUser } = useAuth();
+  const navigate = useNavigate();
+  const [email, setEmail] = useState("");
+  const [password, setPassword] = useState("");
+  const [error, setError] = useState("");
+  const [loading, setLoading] = useState(false);
+
+  async function handleSubmit(e: React.FormEvent) {
+    e.preventDefault();
+    setError("");
+    setLoading(true);
+    try {
+      const user = await login(email, password);
+      setUser(user);
+      navigate("/");
+    } catch (err) {
+      setError(err instanceof Error ? err.message : "Login failed");
+    } finally {
+      setLoading(false);
+    }
+  }
+
+  return (
+    <div className={styles.page}>
+      <div className={styles.card}>
+        <div className={styles.title}>Sign In</div>
+        <form onSubmit={handleSubmit}>
+          <div className={styles.field}>
+            <label className={styles.label}>Email</label>
+            <input
+              className={styles.input}
+              type="email"
+              value={email}
+              onChange={(e) => setEmail(e.target.value)}
+              autoFocus
+              required
+            />
+          </div>
+          <div className={styles.field}>
+            <label className={styles.label}>Password</label>
+            <input
+              className={styles.input}
+              type="password"
+              value={password}
+              onChange={(e) => setPassword(e.target.value)}
+              required
+            />
+          </div>
+          {error && <div className={styles.error}>{error}</div>}
+          <button className={styles.btn} type="submit" disabled={loading}>
+            {loading ? "Signing in…" : "Sign In"}
+          </button>
+        </form>
+        <div className={styles.link}>
+          No account? <Link to="/register">Create one</Link>
+        </div>
+      </div>
+    </div>
+  );
 }
diff --git a/client/src/pages/RegisterPage.module.css b/client/src/pages/RegisterPage.module.css
new file mode 100644
index 0000000..270b95f
--- /dev/null
+++ b/client/src/pages/RegisterPage.module.css
@@ -0,0 +1,84 @@
+.page {
+  display: flex;
+  justify-content: center;
+  align-items: center;
+  min-height: 60vh;
+}
+
+.card {
+  background: var(--card-bg);
+  border: 1px solid var(--border);
+  border-radius: 8px;
+  padding: 2rem;
+  width: 100%;
+  max-width: 380px;
+}
+
+.title {
+  font-size: 1.4rem;
+  font-weight: 700;
+  margin: 0 0 1.5rem;
+  color: var(--accent);
+}
+
+.field {
+  display: flex;
+  flex-direction: column;
+  gap: 0.4rem;
+  margin-bottom: 1rem;
+}
+
+.label {
+  font-size: 0.85rem;
+  color: var(--text-muted, #aaa);
+}
+
+.input {
+  background: var(--input-bg, #1a1a1a);
+  border: 1px solid var(--border);
+  border-radius: 4px;
+  color: var(--text);
+  font-size: 0.95rem;
+  padding: 0.5rem 0.75rem;
+}
+
+.input:focus {
+  outline: none;
+  border-color: var(--accent);
+}
+
+.error {
+  color: #e55;
+  font-size: 0.85rem;
+  margin-bottom: 0.75rem;
+}
+
+.btn {
+  width: 100%;
+  padding: 0.6rem;
+  background: var(--accent);
+  color: #fff;
+  border: none;
+  border-radius: 4px;
+  font-size: 1rem;
+  font-weight: 600;
+  cursor: pointer;
+  margin-top: 0.5rem;
+}
+
+.btn:disabled {
+  opacity: 0.6;
+  cursor: not-allowed;
+}
+
+.link {
+  display: block;
+  text-align: center;
+  margin-top: 1rem;
+  font-size: 0.85rem;
+  color: var(--text-muted, #aaa);
+}
+
+.link a {
+  color: var(--accent);
+}
diff --git a/client/src/pages/RegisterPage.tsx b/client/src/pages/RegisterPage.tsx
index 102d218..17da7e1 100644
--- a/client/src/pages/RegisterPage.tsx
+++ b/client/src/pages/RegisterPage.tsx
@@ -1,3 +1,82 @@
+import { useState } from "react";
+import { useNavigate, Link } from "react-router-dom";
+import { register } from "../api";
+import { useAuth } from "../context/AuthContext";
+import styles from "./RegisterPage.module.css";
+
 export default function RegisterPage() {
-  return <div>Register</div>;
+  const { setUser } = useAuth();
+  const navigate = useNavigate();
+  const [email, setEmail] = useState("");
+  const [username, setUsername] = useState("");
+  const [password, setPassword] = useState("");
+  const [error, setError] = useState("");
+  const [loading, setLoading] = useState(false);
+
+  async function handleSubmit(e: React.FormEvent) {
+    e.preventDefault();
+    setError("");
+    if (password.length < 8) {
+      setError("Password must be at least 8 characters");
+      return;
+    }
+    setLoading(true);
+    try {
+      const user = await register(email, username, password);
+      setUser(user);
+      navigate("/");
+    } catch (err) {
+      setError(err instanceof Error ? err.message : "Registration failed");
+    } finally {
+      setLoading(false);
+    }
+  }
+
+  return (
+    <div className={styles.page}>
+      <div className={styles.card}>
+        <div className={styles.title}>Create Account</div>
+        <form onSubmit={handleSubmit}>
+          <div className={styles.field}>
+            <label className={styles.label}>Email</label>
+            <input
+              className={styles.input}
+              type="email"
+              value={email}
+              onChange={(e) => setEmail(e.target.value)}
+              autoFocus
+              required
+            />
+          </div>
+          <div className={styles.field}>
+            <label className={styles.label}>Username</label>
+            <input
+              className={styles.input}
+              type="text"
+              value={username}
+              onChange={(e) => setUsername(e.target.value)}
+              required
+            />
+          </div>
+          <div className={styles.field}>
+            <label className={styles.label}>Password</label>
+            <input
+              className={styles.input}
+              type="password"
+              value={password}
+              onChange={(e) => setPassword(e.target.value)}
+              required
+            />
+          </div>
+          {error && <div className={styles.error}>{error}</div>}
+          <button className={styles.btn} type="submit" disabled={loading}>
+            {loading ? "Creating account…" : "Create Account"}
+          </button>
+        </form>
+        <div className={styles.link}>
+          Already have an account? <Link to="/login">Sign in</Link>
+        </div>
+      </div>
+    </div>
+  );
 }