@import url(https://fonts.googleapis.com/css?family=Open+Sans:300italic,400italic,600italic,700italic,800italic,400,300,600,700,800);
@import url(https://fonts.googleapis.com/css?family=Roboto+Slab:100,300,500,700);

* {
    -webkit-box-sizing: border-box;
    -moz-box-sizing: border-box;
    box-sizing: border-box
}
html, body, div, span, applet, object, iframe, h1, h2, h3, h4, h5, h6, p, blockquote, pre, a, abbr, acronym, address, big, cite, code, del, dfn, em, img, ins, kbd, q, s, samp, small, strike, strong, sub, sup, tt, var, b, u, i, center, dl, dt, dd, ol, ul, li, fieldset, form, label, legend, table, caption, tbody, tfoot, thead, tr, th, td, article, aside, canvas, details, embed, figure, figcaption, footer, header, hgroup, menu, nav, output, ruby, section, summary, time, mark, audio, video {
    margin: 0;
    padding: 0;
    border: 0;
    font: inherit;
    font-size: 100%;
    vertical-align: baseline
}
table {
    border-collapse: collapse;
    border-spacing: 0
}
caption, th, td {
    text-align: left;
    font-weight: normal;
    vertical-align: middle
}
q, blockquote {
    quotes: none
}
q:before, q:after, blockquote:before, blockquote:after {
    content: "";
    content: none
}
a img {
    border: none
}

article, aside, details, figcaption, figure, footer, header, hgroup, menu, nav, section, summary {
    display: block
}

button, input {
    line-height: normal
}

button, input, select, textarea {
    font-size: 100%;
    margin: 0;
    vertical-align: baseline;
    /* *vertical-align: middle; */
}

button, input[type="button"], input[type="reset"], input[type="submit"] {
    cursor: pointer;
    /* *overflow: visible; */
}

button: : -moz-focus-inner, input: : -moz-focus-inner {
    border: 0;
    padding: 0
}

textarea {
    overflow: auto;
    vertical-align: top;
    resize: vertical
}

.clearfix, .container, section {
    overflow: hidden;
    /* *zoom: 1; */
}

.pie-clearfix {
    /* *zoom: 1; */
}

.pie-clearfix:after {
    content: "";
    display: table;
    clear: both
}

.max-width {
    max-width: 100%;
    height: auto
}

html {
    font-size: 100%
}

body {
    color: #444;
    font-family: Helvetica, Arial, sans-serif
}

a {
    color: #444;
    white-space: pre;
    white-space: pre-wrap;
    white-space: pre-line;
    white-space: -pre-wrap;
    white-space: -o-pre-wrap;
    white-space: -moz-pre-wrap;
    white-space: -hp-pre-wrap;
    word-wrap: break-word
}

a:hover, a:focus, a:active {
    color: #222
}

h1 {
    font-size: 1.875em;
    line-height: 1.33333em;
    margin: 0.53333em 0 0.53333em 0
}

h2 {
    font-size: 1.5em;
    line-height: 1.33333em;
    margin: 1.33333em 0 0.66667em 0
}

h3 {
    font-size: 1.125em;
    line-height: 1.33333em;
    margin: 0.88889em 0 0.88889em 0
}

h4 {
    font-size: 0.875em;
    line-height: 1.71429em;
    margin: 0 0 0.57143em 0
}

h5 {
    font-size: 0.75em;
    line-height: 1.33333em;
    margin: 0 0 0.66667em 0
}

h6 {
    font-size: 0.625em;
    line-height: 1.6em;
    margin: 0 0 0.8em 0
}

p, pre, label {
    font-size: 1em;
    line-height: 1.5em;
    margin: 0 0 1em 0
}

ol, ul {
    font-size: 1em;
    line-height: 1.5em;
    margin: 0 0 2em 0
}

li {
    line-height: auto
}

ul {
    list-style-position: outside;
    list-style-type: disc
}

ol {
    list-style-position: outside;
    list-style-type: decimal
}

strong, b {
    font-weight: 600
}

em, i, q {
    font-style: italic
}

blockquote {
    border-left: none;
    line-height: normal;
    margin: 0;
    color: #222;
    -webkit-column-break-inside: avoid;
    -moz-column-break-inside: avoid;
    -column-break-inside: avoid
}

blockquote p {
    font-family: "Roboto Slab", serif;
    font-style: italic;
    margin: 0;
    font-size: 1.375em;
    line-height: 1.45455em;
    margin: 1.2em 0 1.2em 0
}

label, select {
    display: block
}

input[type="search"] {
    -webkit-box-sizing: content-box;
    -moz-box-sizing: content-box;
    -webkit-appearance: textfield;
    box-sizing: content-box
}

input[type="search"]: : -webkit-search-decoration, input[type="search"]: : -webkit-search-cancel-button {
    -webkit-appearance: none
}

textarea {
    overflow: auto;
    vertical-align: top
}

textarea, input[type="text"], input[type="password"], input[type="datetime"], input[type="datetime-local"], input[type="date"], input[type="month"], input[type="time"], input[type="week"], input[type="number"], input[type="email"], input[type="url"], input[type="search"], input[type="tel"] {
    -webkit-box-shadow: inset 0 1px 1px rgba(0, 0, 0, 0.075);
    -moz-box-shadow: inset 0 1px 1px rgba(0, 0, 0, 0.075);
    box-shadow: inset 0 1px 1px rgba(0, 0, 0, 0.075);
    -webkit-transition: border linear 0.2s, box-shadow linear 0.2s;
    -moz-transition: border linear 0.2s, box-shadow linear 0.2s;
    -o-transition: border linear 0.2s, box-shadow linear 0.2s;
    transition: border linear 0.2s, box-shadow linear 0.2s
}

input[type="radio"], input[type="checkbox"] {
    margin: 4px 0 0;
    margin-top: 1px \9;
    /* *margin-top: 0; */
    line-height: normal;
    cursor: pointer
}

input[type="file"], input[type="image"], input[type="submit"], input[type="reset"], input[type="button"], input[type="radio"], input[type="checkbox"] {
    width: auto
}

select, input[type="file"] {
    /* *margin-top: 4px; */
}

select:focus, input[type="file"]:focus, input[type="radio"]:focus, input[type="checkbox"]:focus {
    outline: thin dotted #333;
    outline: 5px auto -webkit-focus-ring-color;
    outline-offset: -2px
}

.container {
    margin: 0 auto;
    width: 95%
}

ol {
    list-style-position: inside;
    list-style-type: decimal
}

ul {
    list-style-position: inside;
    list-style-type: disc
}

h1, h2, h3 {
    font-family: "Roboto Slab", serif;
    font-weight: 300;
    color: #000
}

body {
    font-family: "Open Sans", sans-serif;
    margin: 0.5em 0.6875em 1.375em 0.6875em;
    font-weight: 300
}

body b, body strong {
    font-weight: 700
}

body bi {
    font-weight: 700;
    font-style: italic
}

.cover {
    -webkit-transition: width 500ms ease-in-out;
    -moz-transition: width 500ms ease-in-out;
    -ms-transition: width 500ms ease-in-out;
    -o-transition: width 500ms ease-in-out;
    transition: width 500ms ease-in-out;
    -webkit-background-size: cover;
    -moz-background-size: cover;
    -o-background-size: cover;
    background-size: cover;
    background-clip: cover;
    position: fixed;
    height: 100%;
    width: 0;
    margin-left: -12080px
}

.issue-notes {
    border-bottom: 1px #c4c4c4 solid
}

.issues {
    background: white;
    padding: 32px 0 0 0
}

.issues ul {
    border-bottom: 1px #c4c4c4 solid;
    margin: 0;
    padding: 10px 0
}

.issues ul li {
    display: inline
}

.issues ul li a {
    text-transform: uppercase;
    text-decoration: none;
    -webkit-transition: color 200ms ease;
    -moz-transition: color 200ms ease;
    -ms-transition: color 200ms ease;
    -o-transition: color 200ms ease;
    transition: color 200ms ease;
    color: #bbb;
    font-weight: 700
}

.issues ul li a:hover {
    color: #0c8
}

.table-of-contents ul li {
    padding-left: 10px
}

.table-of-contents a {
    text-decoration: none
}

.table-of-contents a:hover {
    text-decoration: underline
}

.table-of-contents article {
    margin: 0.9375em 0;
    border-bottom: 1px #c4c4c4 solid;
    text-align: center
}

.table-of-contents .author-avatar {
    float: none;
    max-width: 3em
}

.table-of-contents .article-number {
    font-family: "Roboto Slab", serif;
    font-style: italic;
    position: absolute;
    left: 0;
    top: 0;
    font-size: 0.75em;
    color: #ccc
}

.table-of-contents .summary {
    display: block;
    padding: 0px 0 8px 0
}

.table-of-contents .summary h3, .table-of-contents .summary p {
    font-size: 12px;
    margin: 0.33333em 0 0.33333em 0
}

.table-of-contents .summary h3 .title, .table-of-contents .summary p .title {
    text-transform: uppercase
}

.table-of-contents .summary h3 .author, .table-of-contents .summary p .author {
    color: #bbb
}

.table-of-contents .summary h3 a, .table-of-contents .summary p a {
    text-decoration: none
}

.left-column {
    margin: 0 0 1.25em 0;
    text-align: center
}

.left-column .author {
    padding: 0.625em;
    margin: 0
}

.left-column .author-avatar {
    max-width: 7em
}

.author-avatar {
    background-color: whitesmoke;
    -webkit-mask-image: url(../images/circle-img-mask.png);
    -webkit-mask-size: 100% 100%
}

article header {
    border-bottom: 1px #c4c4c4 solid;
    margin-bottom: 1.25em
}

article footer {
    border-top: 1px #c4c4c4 solid;
    margin-top: 0.625em;
    padding-top: 1.25em;
    text-align: center
}

article footer img {
    width: 2em;
    margin-right: 0.75em;
    vertical-align: middle
}

article .byline {
    font-size: 12px;
    text-transform: uppercase;
    color: #bbb
}

article img {
    width: 100%
}

.paginate {
    opacity: 1;
    -webkit-transition: all 500ms ease;
    -moz-transition: all 500ms ease;
    -ms-transition: all 500ms ease;
    -o-transition: all 500ms ease;
    transition: all 500ms ease
}

.paginate a {
    background-color: rgba(0, 0, 0, 0.15);
    color: #fff;
    font-size: 32px;
    width: 72px;
    line-height: 72px;
    text-align: center;
    text-decoration: none;
    position: fixed;
    top: 50%;
    margin-top: -32px;
    -webkit-border-radius: 64px 64px 64px 64px;
    -moz-border-radius: 64px 64px 64px 64px;
    border-radius: 64px 64px 64px 64px;
    -webkit-transition: all 500ms ease;
    -moz-transition: all 500ms ease;
    -ms-transition: all 500ms ease;
    -o-transition: all 500ms ease;
    transition: all 500ms ease
}

.paginate a.prev {
    left: 0;
    margin-left: 30px;
    padding-right: 4px
}

.paginate a.next {
    right: 0;
    margin-right: 30px;
    padding-left: 4px
}

.paginate a:hover {
    background-color: #0c8
}

.paginate a:hover.prev {
    left: 10px
}

.paginate a:hover.next {
    right: 10px
}

.pull-right {
    float: right
}

.pull-left {
    float: left
}

#title {
    color: #fff;
    font-size: 10em;
    margin: 0;
    font-weight: bold;
    line-height: 130px;
    margin-left: 0.01em;
    text-align: center
}

#subtitle {
    color: #fff;
    text-align: center;
    text-transform: uppercase;
    font-size: 2.5em;
    margin: 0
}

#corp {
    background-image: url("../images/tw-logo-white.png");
    background-repeat: no-repeat;
    height: 32px;
    background-size: auto 100%;
}

.logo {
    position: fixed;
    top: 26px;
    left: 10px;
    padding: 0
}

.gist {
    font-size: 0.8em
}

pre.line-pre {
    white-space: normal !important
}

div.normal-gist pre.line-pre {
    white-space: pre !important
}

.gist-meta {
    display: none
}

footer {
    display: none
}

.snippet {
    font-size: 0.8em;
    margin-left: 2em;
    display: inline-block
}

.computer {
    font-family: "courier new"
}

.inline-code {
    font-family: 'courier new';
    background-color: #f8f8f8;
    border: 1px solid #ddd;
    padding: 0px 5px;
    margin: 0 2px;
    border-radius: 3px
}

@media screen and (max-width: 47.9375em) {
    .logo {
        position: static;
        top: 0;
        left: 0;
        text-align: left
    }

    #title {
        color: #bbb;
        font-size: 2em;
        display: inline-block;
        line-height: 1.0em;
        padding-bottom: 0
    }

    #subtitle {
        color: #bbb;
        font-size: 2em;
        display: inline-block;
        line-height: 1.0em
    }

    #corp {
        background-image: url("../images/tw-logo-grey.png");
        background-repeat: no-repeat;
        height: 22px;
        background-size: auto 100%;
        margin-top: 5px;
    }

    #start-reading {
        display: none
    }
}

@media screen and (min-width: 30em) {
    .container {
        width: 80%
    }
}

@media screen and (min-width: 47.9375em) {
    #bottom-pages {
        display: block
    }

    body {
        margin: 0 0.6875em 1.375em 0.6875em
    }

    .container {
        min-width: 36.625em
    }

    .page {
        margin-left: 11.875em
    }

    .table-of-contents {
        margin-left: 11.875em
    }

    .table-of-contents article {
        position: relative;
        text-align: left
    }

    .table-of-contents .summary {
        margin-left: 2.25em
    }

    .table-of-contents .author-avatar {
        display: none;
        position: absolute;
        right: 0;
        top: 50%;
        width: 100%;
        margin-top: -2.25em
    }

    .cover {
        width: 12044px
    }

    .left-column {
        max-width: 11.875em;
        margin: 3.375em 0 0 -11.875em;
        position: fixed;
        top: 0;
        text-align: center
    }

    .left-column .author-avatar {
        width: 100%;
        max-width: 9.25em;
        text-align: center;
        margin-bottom: 1.25em;
        margin-right: 0
    }

    h1 {
        font-size: 2.375em;
        line-height: 1.26316em;
        margin: 0.42105em 0 0.42105em 0
    }

    h2 {
        font-size: 1.875em;
        line-height: 1.33333em;
        margin: 1.06667em 0 0.53333em 0
    }

    h3 {
        font-size: 1.375em;
        line-height: 1.45455em;
        margin: 0.72727em 0 0.72727em 0
    }

    h4 {
        font-size: 1.25em;
        line-height: 1.2em;
        margin: 0 0 0.4em 0
    }

    h5 {
        font-size: 1.125em;
        line-height: 1.33333em;
        margin: 0 0 0.44444em 0
    }

    h6 {
        font-size: 1em;
        line-height: 1.5em;
        margin: 0 0 0.5em 0
    }

    article footer a img {
        opacity: 0.2;
        width: 2em;
        -webkit-filter: grayscale(100%);
        -moz-filter: grayscale(100%);
        -ms-filter: grayscale(100%);
        -o-filter: grayscale(100%);
        filter: grayscale(100%);
        -webkit-transition: all 500ms ease;
        -moz-transition: all 500ms ease;
        -ms-transition: all 500ms ease;
        -o-transition: all 500ms ease;
        transition: all 500ms ease
    }

    article footer a img:hover {
        opacity: 1;
        -webkit-filter: grayscale(0%);
        -moz-filter: grayscale(0%);
        -ms-filter: grayscale(0%);
        -o-filter: grayscale(0%);
        filter: grayscale(0%)
    }
}

@media screen and (min-width: 64em) {
    .container {
        width: 48em
    }

    .paginate {
        opacity: 1
    }

    .paginate a {
        position: fixed
    }
}

#bottom-pages {
    display: none
}

@media screen and (max-width: 64em) {
    .paginate a {
        position: absolute;
        top: 40px;
        line-height: 36px;
        width: 36px;
        font-size: 18px
    }

    .paginate a.prev {
        left: 0;
        margin-left: 20px;
        padding-right: 4px
    }

    .paginate a.next {
        right: 0;
        margin-right: 20px;
        padding-left: 4px
    }

    .paginate a:hover {
        background-color: #0c8
    }

    .paginate a:hover.prev {
        left: 0
    }

    .paginate a:hover.next {
        right: 0
    }

    #bottom-pages {
        margin-top: -110px;
        display: block
    }

    #bottom-pages .paginate {
        text-align: center
    }

    #bottom-pages .paginate a {
        position: inherit;
        font-size: 18px;
        line-height: 36px;
        width: 36px
    }

    #bottom-pages .paginate a.prev {
        float: left
    }

    #bottom-pages .paginate a.next {
        float: right
    }
}

@media print {
    @page {
        margin: 6.25em
    }

    body {
        line-height: 1em
    }

    .left-column {
        max-width: 10em;
        margin-right: 3em;
        position: fixed;
        border-bottom: none;
        margin-bottom: 0
    }

    .page {
        margin-top: 3em;
        margin-left: 10em
    }

    article footer {
        display: none
    }
}

@media screen and (max-width: 769px) {
    -webkit-text-size-adjust: none
}

.is-hidden {
    display: none
}

.is-shown, .is-block {
    display: block
}

.is-uppercase {
    text-transform: uppercase;
    letter-spacing: 1px
}

.is-lowercase {
    text-transform: lowercase
}

#grid {
    width: 100%;
    position: absolute;
    top: 0;
    left: 0
}

#grid div.horiz {
    height: 8px;
    border-bottom: 1px solid #ddd;
    margin: 0;
    padding: 0
}

.inline-table {
    font-size: 0.8em
}

.inline-table table {
    width: 100%;
    border: 1px dotted #808080;
}

.inline-table td {
    padding: 0.2em;
    border: 1px dotted #808080;
}

.inline-table th {
    text-align: center;
    font-weight: 700;
    min-width: 20px;
    border: 1px dotted #808080;
}

/* new css */
.centered {
    text-align: center;
}