body {
            margin: 0;
            padding: 0;
            font-family: 'Inter', sans-serif;
            background-color: #f9f7ff; /* Màu nền nhẹ nhàng */
            height: 100vh;
            display: flex;
            justify-content: center;
            align-items: center;
        }

        .login-container {
            background: white;
            width: 100%;
            max-width: 400px;
            padding: 30px;
            border-radius: 4px;
            box-shadow: 0 4px 15px rgba(0, 0, 0, 0.1);
            border: 1px solid #ddd;
            text-align: center;
        }

        h2 {
            font-size: 1.2rem;
            color: #333;
            margin-bottom: 25px;
            font-weight: 700;
        }

        .input-group {
            position: relative;
            margin-bottom: 15px;
        }

        .input-group i {
            position: absolute;
            right: 15px;
            top: 50%;
            transform: translateY(-50%);
            color: #888;
        }

        .input-group input {
            width: 100%;
            padding: 12px 15px;
            border: 1px solid #ccc;
            border-radius: 4px;
            box-sizing: border-box;
            outline: none;
            font-size: 0.9rem;
        }

        .options {
            display: flex;
            justify-content: space-between;
            align-items: center;
            font-size: 0.85rem;
            color: #555;
            margin-bottom: 20px;
        }

        .btn-login {
            width: 100%;
            background-color: #007bff;
            color: white;
            padding: 12px;
            border: none;
            border-radius: 4px;
            font-weight: bold;
            cursor: pointer;
            margin-bottom: 20px;
            transition: background 0.3s;
        }

        .btn-login:hover { background-color: #0056b3; }

        .divider {
            position: relative;
            margin: 20px 0;
            color: #888;
            font-size: 0.85rem;
        }

        .divider::before, .divider::after {
            content: "";
            position: absolute;
            top: 50%;
            width: 40%;
            height: 1px;
            background: #ddd;
        }
        .divider::before { left: 0; }
        .divider::after { right: 0; }

        .social-buttons {
            display: grid;
            grid-template-columns: 1fr 1fr 1fr;
            gap: 10px;
            margin-bottom: 15px;
        }

        .social-btn {
            padding: 8px;
            border: none;
            border-radius: 4px;
            color: white;
            font-size: 0.85rem;
            cursor: pointer;
            display: flex;
            align-items: center;
            justify-content: center;
            gap: 5px;
            text-decoration: none;
        }

        .fb { background-color: #3b5998; }
        .ds { background-color: #5865f2; }
        .gg { background-color: #db4437; }
        .zl { background-color: #0068ff; grid-column: span 1; }
        .reg { background-color: #26c2bc; grid-column: span 2; }