diff --git a/src/app/kurslar/[courseSlug]/ogren/page.jsx b/src/app/kurslar/[courseSlug]/ogren/page.jsx
index bc94caa..fb9f3a7 100644
--- a/src/app/kurslar/[courseSlug]/ogren/page.jsx
+++ b/src/app/kurslar/[courseSlug]/ogren/page.jsx
@@ -1,21 +1,26 @@
 "use client";
+import { useState } from "react";
 import styles from "./page.module.css";
 
-const Step = ({ step, completed, onClick }) => (
-	<div className={styles.step} onClick={() => onClick()}>
-		{completed ? "✅" : "◻️"} {step}
-	</div>
-);
+const Step = ({ label }) => {
+	const [isCompleted, setIsCompleted] = useState(false);
+
+	return (
+		<div className={styles.step} onClick={() => setIsCompleted((val) => !val)}>
+			<input type="checkbox" checked={isCompleted} />
+			<span style={{ marginLeft: "0.5rem" }}>{label}</span>
+		</div>
+	);
+};
 
 const Home = () => {
 	return (
 		<div className={styles.container}>
 			<div className={styles.videoContainer}>
 				<iframe
-					src="https://www.youtube.com/embed/VIDEO_ID"
-					title="YouTube video player"
-					frameBorder="0"
-					allow="accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture"
+					src="https://www.youtube.com/embed/r3P58Y1OL0g"
+					// frameBorder="0"
+					allow="autoplay; encrypted-media"
 					allowFullScreen
 					className={styles.video}
 				></iframe>
@@ -25,11 +30,26 @@ const Home = () => {
 				<div className={styles.courseContainer}>
 					<h2>Kurs İçeriği</h2>
 					<div className={styles.courseContent}>
-						<Step step="Adım 1" completed={false} onClick={() => {}} />
-						<Step step="Adım 2" completed={false} onClick={() => {}} />
-						<Step step="Adım 3" completed={false} onClick={() => {}} />
+						<Step label="1. Blokzincir Nedir?" />
+						<Step label="2. Kullanım Alanları" />
+						<Step label="3. Ethereum Nedir?" />
+						<Step label="4. Akıllı Kontratlar" />
+						<Step label="5. Solidity Programlama Dili" />
 					</div>
 				</div>
+
+				<button
+					type="button"
+					className="btn btn-primary"
+					style={{
+						marginTop: "2rem",
+						marginLeft: "auto",
+						marginRight: "auto",
+						display: "block",
+					}}
+				>
+					Sertifikayı Al
+				</button>
 			</div>
 		</div>
 	);
diff --git a/src/app/kurslar/[courseSlug]/ogren/page.module.css b/src/app/kurslar/[courseSlug]/ogren/page.module.css
index c1002f1..17634aa 100644
--- a/src/app/kurslar/[courseSlug]/ogren/page.module.css
+++ b/src/app/kurslar/[courseSlug]/ogren/page.module.css
@@ -4,7 +4,8 @@
 
 .sidebar {
 	width: 500px;
-	padding: 50px;
+	padding: 20px;
+	padding-top: 0;
 	border-left: 2px solid #ccc;
 }
 
@@ -15,16 +16,18 @@
 
 .courseContent {
 	flex: 1;
-	padding: 10px;
 }
 
 .step {
 	cursor: pointer;
 	margin-bottom: 10px;
+	padding: 1rem;
+	background-color: var(--color-bg1);
+	border-radius: var(--border-radius);
 }
 
 .video {
-	width: 120%;
+	width: 100%;
 	max-width: 1000px;
 	aspect-ratio: 16 / 9;
 	display: block;
diff --git a/src/app/kurslar/[courseSlug]/page.jsx b/src/app/kurslar/[courseSlug]/page.jsx
index 10bd7cf..0c16034 100644
--- a/src/app/kurslar/[courseSlug]/page.jsx
+++ b/src/app/kurslar/[courseSlug]/page.jsx
@@ -1,12 +1,33 @@
+"use client";
+
 import Container from "@/components/Container";
+import { CubLearn } from "@/contracts";
 import { COURSES } from "@/mockData";
 import { cn, formatPrice } from "@/utils";
 import Link from "next/link";
+import { useContractRead, useContractWrite, useWalletClient } from "wagmi";
 import styles from "./page.module.css";
 
 export default function CourseDetailPage({ params }) {
+	const { data: walletClient } = useWalletClient();
+
 	const course = COURSES.find((c) => c.slug === params.courseSlug);
 
+	const amIEnrolledInCourse = useContractRead({
+		address: CubLearn.address,
+		abi: CubLearn.abi,
+		functionName: "amIEnrolledInCourse",
+		args: [course.id],
+		account: walletClient?.account,
+	});
+
+	const enroll = useContractWrite({
+		address: CubLearn.address,
+		abi: CubLearn.abi,
+		functionName: "enroll",
+		args: [course.id],
+	});
+
 	return (
 		<main className={styles.root}>
 			<Container>
@@ -19,7 +40,7 @@ export default function CourseDetailPage({ params }) {
 					<div>
 						<h1>{course.name}</h1>
 						<div>{course.instructor.name}</div>
-						{true ? (
+						{amIEnrolledInCourse.data ? (
 							<Link
 								href={`/kurslar/${params.courseSlug}/ogren`}
 								className={cn(styles.button, "btn btn-primary")}
@@ -27,7 +48,11 @@ export default function CourseDetailPage({ params }) {
 								Eğitime Başla
 							</Link>
 						) : (
-							<button className={cn(styles.button, "btn btn-primary")}>
+							<button
+								className={cn(styles.button, "btn btn-primary")}
+								disabled={!enroll.write}
+								onClick={() => enroll.write?.()}
+							>
 								Satın Al: {formatPrice(course.price)}
 							</button>
 						)}
diff --git a/src/components/DTLDisplay.jsx b/src/components/DTLDisplay.jsx
new file mode 100644
index 0000000..ca95a2e
--- /dev/null
+++ b/src/components/DTLDisplay.jsx
@@ -0,0 +1,59 @@
+"use client";
+
+import { CubLearn, DTLToken } from "@/contracts";
+import { useEffect } from "react";
+import {
+	useAccount,
+	useContractRead,
+	useContractWrite,
+	usePrepareContractWrite,
+	useWalletClient,
+} from "wagmi";
+
+export default function DTLDisplay() {
+	const { address } = useAccount();
+	const { data: walletClient } = useWalletClient();
+
+	const getMyBalance = useContractRead({
+		address: DTLToken.address,
+		abi: DTLToken.abi,
+		functionName: "getMyBalance",
+		account: walletClient?.account,
+	});
+
+	const getAllowanceOfSpender = useContractRead({
+		address: DTLToken.address,
+		abi: DTLToken.abi,
+		functionName: "getAllowanceOfSpender",
+		args: [CubLearn.address],
+		account: walletClient?.account,
+	});
+
+	const { config: approveMaxConfig } = usePrepareContractWrite({
+		address: DTLToken.address,
+		abi: DTLToken.abi,
+		functionName: "approveMax",
+		args: [CubLearn.address],
+	});
+	const approveMax = useContractWrite(approveMaxConfig);
+
+	useEffect(() => {
+		if (address) {
+			getMyBalance.refetch();
+		}
+	}, [address]);
+
+	return !getAllowanceOfSpender.data || getAllowanceOfSpender.data === 0n ? (
+		<button
+			type="button"
+			className="btn btn-primary"
+			onClick={() => approveMax.write?.() && getAllowanceOfSpender.refetch()}
+		>
+			APPROVE!!!
+		</button>
+	) : (
+		<button type="button" className="btn btn-flat" disabled>
+			{parseInt(getMyBalance.data)} DTL
+		</button>
+	);
+}
diff --git a/src/components/Header.jsx b/src/components/Header.jsx
index d09f5fe..ba483fd 100644
--- a/src/components/Header.jsx
+++ b/src/components/Header.jsx
@@ -1,6 +1,7 @@
 import { cn } from "@/utils";
 import { ConnectButton } from "@rainbow-me/rainbowkit";
 import Link from "next/link";
+import DTLDisplay from "./DTLDisplay";
 import styles from "./Header.module.css";
 
 export default function Header() {
@@ -16,7 +17,9 @@ export default function Header() {
 					Hesabım
 				</Link>
 
-				<ConnectButton />
+				<DTLDisplay />
+
+				<ConnectButton showBalance={false} />
 			</div>
 		</header>
 	);
diff --git a/src/components/WrapperComponent.jsx b/src/components/WrapperComponent.jsx
index 8ebe652..3b0fafe 100644
--- a/src/components/WrapperComponent.jsx
+++ b/src/components/WrapperComponent.jsx
@@ -33,6 +33,7 @@ export default function WrapperComponent({ children }) {
 					accentColor: "var(--color-accent)",
 				})}
 				locale="tr-TR"
+				coolMode
 			>
 				<WalletManager />
 				{children}
diff --git a/src/contracts.js b/src/contracts.js
new file mode 100644
index 0000000..5f820a4
--- /dev/null
+++ b/src/contracts.js
@@ -0,0 +1,596 @@
+export const DTLToken = {
+	address: "0x205A56Be24CC41d32f1Ec64D19954e9e86398ceC",
+	abi: [
+		{
+			inputs: [
+				{
+					internalType: "address",
+					name: "spender",
+					type: "address",
+				},
+				{
+					internalType: "uint256",
+					name: "allowance",
+					type: "uint256",
+				},
+				{
+					internalType: "uint256",
+					name: "needed",
+					type: "uint256",
+				},
+			],
+			name: "ERC20InsufficientAllowance",
+			type: "error",
+		},
+		{
+			inputs: [
+				{
+					internalType: "address",
+					name: "sender",
+					type: "address",
+				},
+				{
+					internalType: "uint256",
+					name: "balance",
+					type: "uint256",
+				},
+				{
+					internalType: "uint256",
+					name: "needed",
+					type: "uint256",
+				},
+			],
+			name: "ERC20InsufficientBalance",
+			type: "error",
+		},
+		{
+			inputs: [
+				{
+					internalType: "address",
+					name: "approver",
+					type: "address",
+				},
+			],
+			name: "ERC20InvalidApprover",
+			type: "error",
+		},
+		{
+			inputs: [
+				{
+					internalType: "address",
+					name: "receiver",
+					type: "address",
+				},
+			],
+			name: "ERC20InvalidReceiver",
+			type: "error",
+		},
+		{
+			inputs: [
+				{
+					internalType: "address",
+					name: "sender",
+					type: "address",
+				},
+			],
+			name: "ERC20InvalidSender",
+			type: "error",
+		},
+		{
+			inputs: [
+				{
+					internalType: "address",
+					name: "spender",
+					type: "address",
+				},
+			],
+			name: "ERC20InvalidSpender",
+			type: "error",
+		},
+		{
+			anonymous: false,
+			inputs: [
+				{
+					indexed: true,
+					internalType: "address",
+					name: "owner",
+					type: "address",
+				},
+				{
+					indexed: true,
+					internalType: "address",
+					name: "spender",
+					type: "address",
+				},
+				{
+					indexed: false,
+					internalType: "uint256",
+					name: "value",
+					type: "uint256",
+				},
+			],
+			name: "Approval",
+			type: "event",
+		},
+		{
+			anonymous: false,
+			inputs: [
+				{
+					indexed: true,
+					internalType: "address",
+					name: "from",
+					type: "address",
+				},
+				{
+					indexed: true,
+					internalType: "address",
+					name: "to",
+					type: "address",
+				},
+				{
+					indexed: false,
+					internalType: "uint256",
+					name: "value",
+					type: "uint256",
+				},
+			],
+			name: "Transfer",
+			type: "event",
+		},
+		{
+			inputs: [
+				{
+					internalType: "address",
+					name: "spender",
+					type: "address",
+				},
+				{
+					internalType: "uint256",
+					name: "value",
+					type: "uint256",
+				},
+			],
+			name: "approve",
+			outputs: [
+				{
+					internalType: "bool",
+					name: "",
+					type: "bool",
+				},
+			],
+			stateMutability: "nonpayable",
+			type: "function",
+		},
+		{
+			inputs: [
+				{
+					internalType: "address",
+					name: "spender",
+					type: "address",
+				},
+			],
+			name: "approveMax",
+			outputs: [
+				{
+					internalType: "bool",
+					name: "",
+					type: "bool",
+				},
+			],
+			stateMutability: "nonpayable",
+			type: "function",
+		},
+		{
+			inputs: [
+				{
+					internalType: "address",
+					name: "to",
+					type: "address",
+				},
+				{
+					internalType: "uint256",
+					name: "value",
+					type: "uint256",
+				},
+			],
+			name: "transfer",
+			outputs: [
+				{
+					internalType: "bool",
+					name: "",
+					type: "bool",
+				},
+			],
+			stateMutability: "nonpayable",
+			type: "function",
+		},
+		{
+			inputs: [
+				{
+					internalType: "address",
+					name: "from",
+					type: "address",
+				},
+				{
+					internalType: "address",
+					name: "to",
+					type: "address",
+				},
+				{
+					internalType: "uint256",
+					name: "value",
+					type: "uint256",
+				},
+			],
+			name: "transferFrom",
+			outputs: [
+				{
+					internalType: "bool",
+					name: "",
+					type: "bool",
+				},
+			],
+			stateMutability: "nonpayable",
+			type: "function",
+		},
+		{
+			inputs: [
+				{
+					internalType: "address",
+					name: "initialHolder",
+					type: "address",
+				},
+			],
+			stateMutability: "nonpayable",
+			type: "constructor",
+		},
+		{
+			inputs: [
+				{
+					internalType: "address",
+					name: "owner",
+					type: "address",
+				},
+				{
+					internalType: "address",
+					name: "spender",
+					type: "address",
+				},
+			],
+			name: "allowance",
+			outputs: [
+				{
+					internalType: "uint256",
+					name: "",
+					type: "uint256",
+				},
+			],
+			stateMutability: "view",
+			type: "function",
+		},
+		{
+			inputs: [
+				{
+					internalType: "address",
+					name: "account",
+					type: "address",
+				},
+			],
+			name: "balanceOf",
+			outputs: [
+				{
+					internalType: "uint256",
+					name: "",
+					type: "uint256",
+				},
+			],
+			stateMutability: "view",
+			type: "function",
+		},
+		{
+			inputs: [],
+			name: "decimals",
+			outputs: [
+				{
+					internalType: "uint8",
+					name: "",
+					type: "uint8",
+				},
+			],
+			stateMutability: "view",
+			type: "function",
+		},
+		{
+			inputs: [
+				{
+					internalType: "address",
+					name: "spender",
+					type: "address",
+				},
+			],
+			name: "getAllowanceOfSpender",
+			outputs: [
+				{
+					internalType: "uint256",
+					name: "",
+					type: "uint256",
+				},
+			],
+			stateMutability: "view",
+			type: "function",
+		},
+		{
+			inputs: [],
+			name: "getMyBalance",
+			outputs: [
+				{
+					internalType: "uint256",
+					name: "",
+					type: "uint256",
+				},
+			],
+			stateMutability: "view",
+			type: "function",
+		},
+		{
+			inputs: [],
+			name: "name",
+			outputs: [
+				{
+					internalType: "string",
+					name: "",
+					type: "string",
+				},
+			],
+			stateMutability: "view",
+			type: "function",
+		},
+		{
+			inputs: [],
+			name: "symbol",
+			outputs: [
+				{
+					internalType: "string",
+					name: "",
+					type: "string",
+				},
+			],
+			stateMutability: "view",
+			type: "function",
+		},
+		{
+			inputs: [],
+			name: "totalSupply",
+			outputs: [
+				{
+					internalType: "uint256",
+					name: "",
+					type: "uint256",
+				},
+			],
+			stateMutability: "view",
+			type: "function",
+		},
+	],
+};
+
+export const CubLearn = {
+	address: "0x2eA6235131CC9233aAD3842C5d14C9Cf7107FdA1",
+	abi: [
+		{
+			inputs: [
+				{
+					internalType: "address",
+					name: "owner",
+					type: "address",
+				},
+			],
+			name: "OwnableInvalidOwner",
+			type: "error",
+		},
+		{
+			inputs: [
+				{
+					internalType: "address",
+					name: "account",
+					type: "address",
+				},
+			],
+			name: "OwnableUnauthorizedAccount",
+			type: "error",
+		},
+		{
+			anonymous: false,
+			inputs: [
+				{
+					indexed: true,
+					internalType: "address",
+					name: "previousOwner",
+					type: "address",
+				},
+				{
+					indexed: true,
+					internalType: "address",
+					name: "newOwner",
+					type: "address",
+				},
+			],
+			name: "OwnershipTransferred",
+			type: "event",
+		},
+		{
+			inputs: [
+				{
+					internalType: "string",
+					name: "courseId",
+					type: "string",
+				},
+			],
+			name: "enroll",
+			outputs: [],
+			stateMutability: "nonpayable",
+			type: "function",
+		},
+		{
+			inputs: [
+				{
+					internalType: "string",
+					name: "courseId",
+					type: "string",
+				},
+				{
+					internalType: "string",
+					name: "studentFullName",
+					type: "string",
+				},
+				{
+					internalType: "string",
+					name: "courseName",
+					type: "string",
+				},
+				{
+					internalType: "string",
+					name: "instructorFullName",
+					type: "string",
+				},
+			],
+			name: "finishCourse",
+			outputs: [],
+			stateMutability: "nonpayable",
+			type: "function",
+		},
+		{
+			inputs: [],
+			name: "renounceOwnership",
+			outputs: [],
+			stateMutability: "nonpayable",
+			type: "function",
+		},
+		{
+			inputs: [
+				{
+					internalType: "uint256",
+					name: "newValue",
+					type: "uint256",
+				},
+			],
+			name: "setCashbackPercentage",
+			outputs: [],
+			stateMutability: "nonpayable",
+			type: "function",
+		},
+		{
+			inputs: [],
+			name: "transferAllDTLBalanceToMe",
+			outputs: [],
+			stateMutability: "nonpayable",
+			type: "function",
+		},
+		{
+			inputs: [
+				{
+					internalType: "address",
+					name: "newOwner",
+					type: "address",
+				},
+			],
+			name: "transferOwnership",
+			outputs: [],
+			stateMutability: "nonpayable",
+			type: "function",
+		},
+		{
+			inputs: [
+				{
+					internalType: "address",
+					name: "dtlContractAddress",
+					type: "address",
+				},
+				{
+					internalType: "address",
+					name: "cubcertContractAddress",
+					type: "address",
+				},
+			],
+			stateMutability: "nonpayable",
+			type: "constructor",
+		},
+		{
+			inputs: [
+				{
+					internalType: "string",
+					name: "courseId",
+					type: "string",
+				},
+			],
+			name: "amIEnrolledInCourse",
+			outputs: [
+				{
+					internalType: "bool",
+					name: "",
+					type: "bool",
+				},
+			],
+			stateMutability: "view",
+			type: "function",
+		},
+		{
+			inputs: [],
+			name: "cashbackPercentage",
+			outputs: [
+				{
+					internalType: "uint256",
+					name: "",
+					type: "uint256",
+				},
+			],
+			stateMutability: "view",
+			type: "function",
+		},
+		{
+			inputs: [
+				{
+					internalType: "string",
+					name: "courseId",
+					type: "string",
+				},
+			],
+			name: "didICompleteCourse",
+			outputs: [
+				{
+					internalType: "bool",
+					name: "",
+					type: "bool",
+				},
+			],
+			stateMutability: "view",
+			type: "function",
+		},
+		{
+			inputs: [],
+			name: "getDTLBalance",
+			outputs: [
+				{
+					internalType: "uint256",
+					name: "",
+					type: "uint256",
+				},
+			],
+			stateMutability: "view",
+			type: "function",
+		},
+		{
+			inputs: [],
+			name: "owner",
+			outputs: [
+				{
+					internalType: "address",
+					name: "",
+					type: "address",
+				},
+			],
+			stateMutability: "view",
+			type: "function",
+		},
+	],
+};