entryPage.js

import React from "react";
import { Switch, Route } from "react-router-dom";
import { Link } from "react-router-dom";

import Login from "./login";
import Register from "./register";
import Welcome from "./welcome";

const formStyle = {
    fontSize: "1.5em",
    padding: "5px",
    float: "left",
    borderRadius: "5px",
    width: "50%",
    height: "50px",
    textAlign: "center",
    margin: "10px 0",
    color: "rgba(46, 79, 96, 0.7)"
};

const switchBox = {
    borderRadius: "5px",
    boxShadow: "-12px 11px 34px -1px rgba(44,62,80,0.34)",
    display: "inline-block",
    width: "100%",
    backgroundColor: "rgba(116, 208, 146, 0.2)",
    padding: "30px 20px 20px 20px",
    minHeight: "400px",
    positon: "relative"
};

class EntryPage extends React.Component {
    constructor(props) {
        super(props);
    }

    render() {
        return (
            <div className="row" style={{ marginTop: "100px" }}>
                <div className="col-12 col-sm-12 col-md-12 col-lg-6 col-xl-6">
                    <Welcome />
                </div>
                <div className="col-12 col-sm-12 col-md-12 col-lg-6 col-xl-6 table">
                    <div>
                        <Link to="/"><h3 style={formStyle} className={ window.location.hash.indexOf("/register") !== -1 ? "hover" : "hover checked"} onClick={this.changeClass} >Log In</h3></Link>
                        <Link to="/register"><h3 style={formStyle} className={ window.location.hash.indexOf("/register") !== -1 ? "hover checked" : "hover"}>Register</h3></Link>
                    </div>
                    <div style={switchBox}>
                        <div>
                            <Switch>
                                <Route exact path="/login" component={Login} />
                                <Route exact path="/register" component={Register} />
                            </Switch>
                        </div>
                    </div>
                </div>
            </div>

        );
    }
}

export default EntryPage;