diff --git a/package.json b/package.json
index 18d507095..e77cf7d64 100644
--- a/package.json
+++ b/package.json
@@ -72,7 +72,7 @@
     "react": "15.1.0",
     "react-dom": "15.0.1",
     "react-intl": "2.1.2",
-    "react-modal": "1.3.0",
+    "react-modal": "1.5.2",
     "react-onclickoutside": "4.1.1",
     "react-redux": "4.4.5",
     "react-responsive": "1.1.4",
diff --git a/src/components/intro/intro.jsx b/src/components/intro/intro.jsx
index acc1de4a7..b9372adbf 100644
--- a/src/components/intro/intro.jsx
+++ b/src/components/intro/intro.jsx
@@ -1,16 +1,13 @@
 var connect = require('react-redux').connect;
-var omit = require('lodash.omit');
 var React = require('react');
 
 var sessionActions = require('../../redux/session.js');
 
-var Modal = require('../modal/modal.jsx');
+var IframeModal = require('../modal/iframe/modal.jsx');
 var Registration = require('../registration/registration.jsx');
 
 require('./intro.scss');
 
-Modal.setAppElement(document.getElementById('view'));
-
 var Intro = React.createClass({
     type: 'Intro',
     getDefaultProps: function () {
@@ -52,11 +49,6 @@ var Intro = React.createClass({
         this.closeRegistration();
     },
     render: function () {
-        var frameProps = {
-            width: 570,
-            height: 357,
-            padding: 15
-        };
         return (
             <div className="intro">
                 <div className="content">
@@ -130,15 +122,12 @@ var Intro = React.createClass({
                     <img src="//cdn.scratch.mit.edu/scratchr2/static/images/hp-video-screenshot.png"
                          alt="Intro Video" />
                 </div>
-                <Modal
-                        className="video-modal"
-                        isOpen={this.state.videoOpen}
-                        onRequestClose={this.closeVideo}
-                        style={{content:frameProps}}>
-                    <iframe
-                        src="//player.vimeo.com/video/65583694?title=0&amp;byline=0&amp;portrait=0"
-                        {...omit(frameProps, 'padding')} />
-                </Modal>
+                <IframeModal
+                    className="mod-intro-video"
+                    isOpen={this.state.videoOpen}
+                    onRequestClose={this.closeVideo}
+                    src="//player.vimeo.com/video/65583694?title=0&amp;byline=0&amp;portrait=0"
+                />
             </div>
         );
     }
diff --git a/src/components/intro/intro.scss b/src/components/intro/intro.scss
index 7d4be04ac..f827c9431 100644
--- a/src/components/intro/intro.scss
+++ b/src/components/intro/intro.scss
@@ -241,3 +241,13 @@
         }
     }
 }
+
+.modal-content.mod-intro-video {
+    padding: 15px;
+    width: 35.625rem;
+}
+
+.modal-content-iframe.mod-intro-video {
+    width: 35.625rem;
+    min-height: 22.3125rem;
+}
diff --git a/src/components/modal/base/modal.jsx b/src/components/modal/base/modal.jsx
new file mode 100644
index 000000000..8492f83f5
--- /dev/null
+++ b/src/components/modal/base/modal.jsx
@@ -0,0 +1,58 @@
+var classNames = require('classnames');
+var omit = require('lodash.omit');
+var React = require('react');
+var ReactModal = require('react-modal');
+
+require('./modal.scss');
+
+/**
+ * Container for pop up windows (See: registration window)
+ */
+var Modal = React.createClass({
+    type: 'Modal',
+    statics: {
+        setAppElement: ReactModal.setAppElement
+    },
+    propTypes: {
+        className: React.PropTypes.string,
+        overlayClassName: React.PropTypes.string
+    },
+    getDefaultProps: function () {
+        return {
+            className: '',
+            overlayClassName: ''
+        };
+    },
+    requestClose: function () {
+        return this.refs.modal.portal.requestClose();
+    },
+    render: function () {
+        var modalClasses = classNames(
+            'modal-content',
+            this.props.className
+        );
+        var overlayClasses = classNames(
+            'modal-overlay',
+            this.props.overlayClassName
+        );
+        return (
+            <ReactModal
+                ref="modal"
+                className={modalClasses}
+                overlayClassName={overlayClasses}
+                {...omit(this.props, ['className', 'overlayClassName'])}
+            >
+                <div className="modal-content-close" onClick={this.requestClose}>
+                    <img
+                        className="modal-content-close-img"
+                        src="/svgs/modal/close-x.svg"
+                        alt="close-icon"
+                    />
+                </div>
+                {this.props.children}
+            </ReactModal>
+        );
+    }
+});
+
+module.exports = Modal;
diff --git a/src/components/modal/base/modal.scss b/src/components/modal/base/modal.scss
new file mode 100644
index 000000000..3d01d683f
--- /dev/null
+++ b/src/components/modal/base/modal.scss
@@ -0,0 +1,61 @@
+@import "../../../colors";
+@import "../../../frameless";
+
+.modal-content {
+    position: relative;
+    margin: 3.75rem auto;
+    border-radius: 1rem;
+    box-shadow: 0 0 0 1px $active-gray;
+    background-color: $ui-white;
+    padding: 0;
+    width: 48.75rem;
+}
+
+.modal-overlay {
+    position: fixed;
+    top: 0;
+    right: 0;
+    bottom: 0;
+    left: 0;
+    z-index: 100;
+    background-color: transparentize($ui-blue, .3);
+}
+
+.ReactModal__Content:focus {
+    outline: none;
+}
+
+$modal-close-size: 1rem;
+.modal-content-close {
+    position: absolute;
+    top: $modal-close-size / 2;
+    right: $modal-close-size / 2;
+    border-radius: $modal-close-size;
+    background-color: $active-dark-gray;
+    cursor: pointer;
+    width: $modal-close-size * 2;
+    height: $modal-close-size * 2;
+    text-align: center;
+    line-height: $modal-close-size * 2;
+}
+
+.modal-content-close-img {
+    padding-top: $modal-close-size / 2;
+}
+
+@media only screen and (max-width: $desktop - 1) {
+    .modal-content {
+        top: 0;
+        left: 0;
+        margin-top: 0;
+        border-radius: 0;
+        box-shadow: none;
+        width: 100%;
+        height: 100%;
+        overflow: scroll;
+    }
+
+    .modal-content-close {
+        position: fixed;
+    }
+}
diff --git a/src/components/modal/iframe/modal.jsx b/src/components/modal/iframe/modal.jsx
new file mode 100644
index 000000000..5d69ea2eb
--- /dev/null
+++ b/src/components/modal/iframe/modal.jsx
@@ -0,0 +1,47 @@
+var classNames = require('classnames');
+var React = require('react');
+
+var Modal = require('../base/modal.jsx');
+
+require('./modal.scss');
+
+Modal.setAppElement(document.getElementById('view'));
+
+var IframeModal = React.createClass({
+    propTypes: {
+        componentKey: React.PropTypes.string,
+        isOpen: React.PropTypes.bool,
+        onRequestClose: React.PropTypes.func,
+        className: React.PropTypes.string,
+        componentRef: React.PropTypes.string,
+        src: React.PropTypes.string
+    },
+    getDefaultProps: function () {
+        return {
+            className: '',
+            iframeClassName: ''
+        };
+    },
+    render: function () {
+        var iframeClasses = classNames(
+            'modal-content-iframe',
+            this.props.className
+        );
+        return (
+            <Modal
+                key={this.props.componentKey}
+                isOpen={this.props.isOpen}
+                onRequestClose={this.props.onRequestClose}
+                className={this.props.className}
+            >
+                <iframe
+                    ref={this.props.componentRef}
+                    src={this.props.src}
+                    className={iframeClasses}
+                />
+            </Modal>
+        );
+    }
+});
+
+module.exports = IframeModal;
diff --git a/src/components/modal/iframe/modal.scss b/src/components/modal/iframe/modal.scss
new file mode 100644
index 000000000..8c2a43a03
--- /dev/null
+++ b/src/components/modal/iframe/modal.scss
@@ -0,0 +1,5 @@
+@import "../../../frameless";
+
+.modal-content-iframe {
+    border: 0;
+}
diff --git a/src/components/modal/modal.jsx b/src/components/modal/modal.jsx
deleted file mode 100644
index 0e1d68c6e..000000000
--- a/src/components/modal/modal.jsx
+++ /dev/null
@@ -1,64 +0,0 @@
-var clone = require('lodash.clone');
-var defaultsDeep = require('lodash.defaultsdeep');
-var React = require('react');
-var ReactModal = require('react-modal');
-
-require('./modal.scss');
-
-var defaultStyle = {
-    overlay: {
-        zIndex: 100,
-        backgroundColor: 'rgba(0, 0, 0, .75)'
-    },
-    content: {
-        position: 'absolute',
-        overflow: 'visible',
-        borderRadius: '6px',
-        width: 500,
-        height: 250,
-        padding: 0,
-        top: '50%',
-        right: 'auto',
-        bottom: 'auto',
-        left: '50%',
-        marginTop: -125,
-        marginLeft: -250
-    }
-};
-
-/**
- * Container for pop up windows (See: registration window)
- */
-var Modal = React.createClass({
-    type: 'Modal',
-    statics: {
-        setAppElement: ReactModal.setAppElement
-    },
-    getDefaultProps: function () {
-        return {
-            style: defaultStyle
-        };
-    },
-    calculateStyle: function () {
-        var style = clone(this.props.style, true);
-        defaultsDeep(style, defaultStyle);
-        style.content.marginTop = (style.content.height + style.content.padding*2) / -2;
-        style.content.marginLeft = (style.content.width + style.content.padding*2) / -2;
-        return style;
-    },
-    requestClose: function () {
-        return this.refs.modal.portal.requestClose();
-    },
-    render: function () {
-        return (
-            <ReactModal ref="modal"
-                        {...this.props}
-                        style={this.calculateStyle()}>
-                <div className="modal-close" onClick={this.requestClose}></div>
-                {this.props.children}
-            </ReactModal>
-        );
-    }
-});
-
-module.exports = Modal;
diff --git a/src/components/modal/modal.scss b/src/components/modal/modal.scss
deleted file mode 100644
index bafe217d6..000000000
--- a/src/components/modal/modal.scss
+++ /dev/null
@@ -1,34 +0,0 @@
-@import "../../colors";
-
-.ReactModal__Content {
-    &:focus {
-        outline: none;
-    }
-
-    iframe {
-        border: 0;
-    }
-}
-
-.modal-close {
-    $modal-close-size: 20px;
-    position: absolute;
-    top: 0;
-    right: 0;
-    margin-top: -$modal-close-size / 2;
-    margin-right: -$modal-close-size / 2;
-    border: 2px solid $ui-border;
-    border-radius: $modal-close-size / 2;
-    background-color: $active-dark-gray;
-    cursor: pointer;
-    width: $modal-close-size;
-    height: $modal-close-size;
-    text-align: center;
-    line-height: $modal-close-size;
-    color: $type-white;
-    font-size: $modal-close-size;
-
-    &:before {
-        content: "x";
-    }
-}
diff --git a/src/components/navigation/container/navigation.jsx b/src/components/navigation/base/navigation.jsx
similarity index 100%
rename from src/components/navigation/container/navigation.jsx
rename to src/components/navigation/base/navigation.jsx
diff --git a/src/components/navigation/container/navigation.scss b/src/components/navigation/base/navigation.scss
similarity index 100%
rename from src/components/navigation/container/navigation.scss
rename to src/components/navigation/base/navigation.scss
diff --git a/src/components/navigation/conference/navigation.jsx b/src/components/navigation/conference/navigation.jsx
index 72ab5ff8b..7e1192650 100644
--- a/src/components/navigation/conference/navigation.jsx
+++ b/src/components/navigation/conference/navigation.jsx
@@ -1,6 +1,6 @@
 var React = require('react');
 
-var NavigationBox = require('../container/navigation.jsx');
+var NavigationBox = require('../base/navigation.jsx');
 
 require('./navigation.scss');
 
diff --git a/src/components/navigation/www/navigation.jsx b/src/components/navigation/www/navigation.jsx
index d2ffc819b..8bd969917 100644
--- a/src/components/navigation/www/navigation.jsx
+++ b/src/components/navigation/www/navigation.jsx
@@ -15,8 +15,8 @@ var Form = require('../../forms/form.jsx');
 var Input = require('../../forms/input.jsx');
 var log = require('../../../lib/log.js');
 var Login = require('../../login/login.jsx');
-var Modal = require('../../modal/modal.jsx');
-var NavigationBox = require('../container/navigation.jsx');
+var Modal = require('../../modal/base/modal.jsx');
+var NavigationBox = require('../base/navigation.jsx');
 var Registration = require('../../registration/registration.jsx');
 
 require('./navigation.scss');
diff --git a/src/components/registration/registration.jsx b/src/components/registration/registration.jsx
index 126e7a6bc..d234e7286 100644
--- a/src/components/registration/registration.jsx
+++ b/src/components/registration/registration.jsx
@@ -1,10 +1,8 @@
 var React = require('react');
-var Modal = require('../modal/modal.jsx');
+var IframeModal = require('../modal/iframe/modal.jsx');
 
 require('./registration.scss');
 
-Modal.setAppElement(document.getElementById('view'));
-
 var Registration = React.createClass({
     propTypes: {
         isOpen: React.PropTypes.bool,
@@ -36,18 +34,14 @@ var Registration = React.createClass({
         this.toggleMessageListener(false);
     },
     render: function () {
-        var frameProps = {
-            width: 610,
-            height: 438
-        };
         return (
-            <Modal
-                    isOpen={this.props.isOpen}
-                    onRequestClose={this.props.onRequestClose}
-                    className="registration"
-                    style={{content:frameProps}}>
-                <iframe ref="registrationIframe" src="/accounts/standalone-registration/" {...frameProps} />
-            </Modal>
+            <IframeModal
+                isOpen={this.props.isOpen}
+                onRequestClose={this.props.onRequestClose}
+                className="mod-registration"
+                componentRef="registrationIframe"
+                src="/accounts/standalone-registration/"
+            />
         );
     }
 });
diff --git a/src/components/registration/registration.scss b/src/components/registration/registration.scss
index 7ed0be13d..b6ecb42ee 100644
--- a/src/components/registration/registration.scss
+++ b/src/components/registration/registration.scss
@@ -1,3 +1,22 @@
-.registration {
+@import "../../frameless";
+
+.modal-content.mod-registration {
+    width: 38.125rem;
     overflow: hidden;
 }
+
+.modal-content-iframe.mod-registration {
+    width: 38.125rem;
+    min-height: 27.375rem;
+}
+
+@media only screen and (max-width: $tablet - 1) {
+    .modal-content.mod-registration {
+        width: 100%;
+        overflow: scroll;
+    }
+
+    .modal-content-iframe.mod-registration {
+        height: 27.375rem;
+    }
+}
diff --git a/src/views/splash/splash.jsx b/src/views/splash/splash.jsx
index 4849312ab..b90a858bf 100644
--- a/src/views/splash/splash.jsx
+++ b/src/views/splash/splash.jsx
@@ -1,6 +1,5 @@
 var connect = require('react-redux').connect;
 var injectIntl = require('react-intl').injectIntl;
-var omit = require('lodash.omit');
 var React = require('react');
 
 var api = require('../../lib/api');
@@ -16,7 +15,7 @@ var Box = require('../../components/box/box.jsx');
 var Button = require('../../components/forms/button.jsx');
 var Carousel = require('../../components/carousel/carousel.jsx');
 var Intro = require('../../components/intro/intro.jsx');
-var Modal = require('../../components/modal/modal.jsx');
+var IframeModal = require('../../components/modal/iframe/modal.jsx');
 var News = require('../../components/news/news.jsx');
 var Page = require('../../components/page/www/page.jsx');
 var TeacherBanner = require('../../components/teacher-banner/teacher-banner.jsx');
@@ -308,7 +307,6 @@ var Splash = injectIntl(React.createClass({
     },
     render: function () {
         var featured = this.renderHomepageRows();
-        var emailConfirmationStyle = {width: 500, height: 330, padding: 1};
         var homepageCacheState = this.getHomepageRefreshStatus();
 
         var formatHTMLMessage = this.props.intl.formatHTMLMessage;
@@ -344,21 +342,23 @@ var Splash = injectIntl(React.createClass({
         return (
             <div className="splash">
                 {this.shouldShowEmailConfirmation() ? [
-                    <DropdownBanner key="confirmedEmail"
-                            className="warning"
-                            onRequestDismiss={this.handleDismiss.bind(this, 'confirmed_email')}>
+                    <DropdownBanner
+                        key="confirmedEmail"
+                        className="warning"
+                        onRequestDismiss={this.handleDismiss.bind(this, 'confirmed_email')}
+                    >
                         <a href="#" onClick={this.showEmailConfirmationModal}>Confirm your email</a>
                         {' '}to enable sharing.{' '}
                         <a href="/info/faq/#accounts">Having trouble?</a>
                     </DropdownBanner>,
-                    <Modal key="emailConfirmationModal"
-                           isOpen={this.state.emailConfirmationModalOpen}
-                           onRequestClose={this.hideEmailConfirmationModal}
-                           style={{content: emailConfirmationStyle}}>
-                        <iframe ref="emailConfirmationiFrame"
-                                src="/accounts/email_resend_standalone/"
-                                {...omit(emailConfirmationStyle, 'padding')} />
-                    </Modal>
+                    <IframeModal
+                        componentKey="emailConfirmationModal"
+                        isOpen={this.state.emailConfirmationModalOpen}
+                        onRequestClose={this.hideEmailConfirmationModal}
+                        className="mod-confirmation"
+                        componentRef="emailConfirmationiFrame"
+                        src="/accounts/email_resend_standalone/"
+                    />
                 ] : []}
                 {this.props.permissions.educator ? [
                     <TeacherBanner key="teacherbanner" messages={messages} />
diff --git a/src/views/splash/splash.scss b/src/views/splash/splash.scss
index 841b2c73a..3cb87e3ba 100644
--- a/src/views/splash/splash.scss
+++ b/src/views/splash/splash.scss
@@ -42,6 +42,16 @@
     }
 }
 
+.modal-content.mod-confirmation {
+    width: 31.25rem;
+}
+
+.modal-content-iframe.mod-confirmation {
+    border-radius: 1rem;
+    width: 31.25rem;
+    min-height: 20.625rem;
+}
+
 //4 columns
 @media only screen and (max-width: $mobile - 1) {
     .splash {
@@ -54,6 +64,15 @@
             }
         }
     }
+
+    .modal-content.mod-confirmation {
+        width: 100%;
+        overflow: scroll;
+    }
+
+    .modal-content-iframe.mod-confirmation {
+        border-radius: 0;
+    }
 }
 
 //6 columns
@@ -68,6 +87,16 @@
             }
         }
     }
+
+    .modal-content.mod-confirmation {
+        width: 100%;
+        overflow: scroll;
+    }
+
+    .modal-content-iframe.mod-confirmation {
+        border-radius: 0;
+        width: $tablet - 1;
+    }
 }
 
 //6 columns
diff --git a/static/svgs/modal/close-x.svg b/static/svgs/modal/close-x.svg
new file mode 100644
index 000000000..ae4c8027e
--- /dev/null
+++ b/static/svgs/modal/close-x.svg
@@ -0,0 +1,17 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!-- Generator: Adobe Illustrator 19.2.1, SVG Export Plug-In . SVG Version: 6.00 Build 0)  -->
+<svg version="1.1" id="Layer_1" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" x="0px" y="0px"
+	 width="16px" height="16px" viewBox="0 0 16 16" style="enable-background:new 0 0 16 16;" xml:space="preserve">
+<style type="text/css">
+	.st0{fill:#FFFFFF;}
+</style>
+<g>
+	<g>
+		<g>
+			<path class="st0" d="M12.5,10.3c0.6,0.6,0.6,1.5,0,2.1c-0.3,0.3-0.7,0.4-1.1,0.4c-0.4,0-0.8-0.1-1.1-0.4L8,10.1l-2.3,2.3
+				c-0.3,0.3-0.7,0.4-1.1,0.4c-0.4,0-0.8-0.1-1.1-0.4c-0.6-0.6-0.6-1.5,0-2.1L5.9,8L3.5,5.7C3,5.1,3,4.1,3.5,3.5
+				C4.1,3,5.1,3,5.7,3.5L8,5.9l2.3-2.3c0.6-0.6,1.5-0.6,2.1,0c0.6,0.6,0.6,1.5,0,2.1L10.1,8L12.5,10.3z"/>
+		</g>
+	</g>
+</g>
+</svg>