ValidateEmail_content_main.xml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    app:layout_behavior="@string/appbar_scrolling_view_behavior"
    tools:context="com.codecode.validateemail.MainActivity"
    tools:showIn="@layout/activity_main">

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:gravity="center_horizontal"
        android:layout_margin="20dp"
        android:orientation="vertical">
        <TextView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="LOGIN"
            android:textColor="@color/colorAccent"
            android:textStyle="bold"
            android:textSize="30sp" />

    <EditText
        android:id="@+id/edt_email"
        android:layout_width="match_parent"
        android:layout_height="40dp"
        android:layout_margin="20dp"
        android:background="@android:color/darker_gray"
        android:paddingLeft="20dp"
        android:hint="Email"
        android:inputType="text"
        android:textColor="@android:color/black"
        android:textSize="20sp" />

    <EditText
        android:id="@+id/edt_password"
        android:layout_width="match_parent"
        android:layout_height="40dp"
        android:layout_margin="20dp"
        android:background="@android:color/darker_gray"
        android:paddingLeft="20dp"
        android:hint="Password"
        android:inputType="textPassword"
        android:textColor="@android:color/black"
        android:textSize="20sp" />

    <Button
        android:id="@+id/button_password"
        android:layout_width="match_parent"
        android:layout_height="50dp"
        android:layout_margin="20dp"
        android:background="@color/colorAccent"
        android:hint="Login"
        android:textColor="@android:color/white"
        android:textSize="20sp" />
    </LinearLayout>
</RelativeLayout>