zulip/static/styles/rendered_markdown.css

.rendered_markdown {
    /* The default top/bottom margins for paragraphs are small, to make sure
       they look nice next to blockquotes, lists, etc. */
    p {
        margin: 3px 0;
    }

    /* The spacing between two paragraphs is significantly larger.  We
       arrange things so that this spacing matches the spacing between
       paragraphs in two consecutive 1-line messages. */
    p + p {
        margin-top: 10px;
    }

    /* Ensure bulleted lists are nicely centered in 1-line messages */
    ul {
        margin: 2px 0 5px 20px;
    }

    /* Swap the left and right margins of bullets for Right-To-Left languages */
    &.rtl ul {
        margin-right: 20px;
        margin-left: 0;
    }

    /* Ensure ordered lists are nicely centered in 1-line messages */
    ol {
        margin: 2px 0 5px 20px;
    }

    /* Swap the left and right margins of ordered list for Right-To-Left languages */
    &.rtl ol {
        margin-right: 8px;
        margin-left: 0;
    }

    /* Reduce top-margin when a paragraph is followed by an ordered or bulleted list */
    p + ul,
    p + ol {
        margin-top: 0;
    }

    hr {
        border-bottom: 1px solid hsl(0, 0%, 87%);
        border-top: 1px solid hsl(0, 0%, 87%);
    }

    /* Headings */
    h1,
    h2,
    h3,
    h4,
    h5,
    h6 {
        font-weight: 600;
        line-height: 1.4;
        margin-top: 15px;
        margin-bottom: 5px;
    }

    /* Headings: Ensure that messages that start with a heading don't have
       a weirdly blank area at the very start of the message. */
    h1:first-child,
    h2:first-child,
    h3:first-child,
    h4:first-child,
    h5:first-child,
    h6:first-child {
        margin-top: 0;
    }

    /* We use a modest progression of heading sizes to make them stand out
       from normal next but avoid taking up too much space. */
    h1 {
        font-size: 1.4em;
    }

    h2 {
        font-size: 1.3em;
    }

    h3 {
        font-size: 1.2em;
    }

    h4 {
        font-size: 1.1em;
    }

    h5 {
        font-size: 1.05em;
    }

    h6 {
        font-size: 1em;
    }

    /* Formatting for blockquotes */
    blockquote {
        padding-left: 5px;
        margin-left: 10px;
        margin-top: 5px;
        margin-bottom: 6px;
        border-left-color: hsl(0, 0%, 87%);

        p {
            line-height: inherit;
            font-size: inherit;
        }
    }

    &.rtl blockquote {
        padding-left: unset;
        padding-right: 5px;
        margin-left: unset;
        margin-right: 10px;
        border-left: unset;
        border-right: 5px solid hsl(0, 0%, 87%);
    }

    /* Formatting for Markdown tables */
    table {
        padding-right: 10px;
        margin: 5px;
        width: 99%;
        display: block;
        max-width: fit-content;
        overflow-x: auto;
        white-space: nowrap;
    }

    thead {
        background-color: hsl(0, 0%, 93%);
    }

    tr {
        display: table-row;
        vertical-align: inherit;
    }

    tr th {
        border: 1px solid hsl(0, 0%, 80%);
        padding: 4px;
        text-align: left;
    }

    tr td {
        border: 1px solid hsl(0, 0%, 80%);
        padding: 4px;
    }

    /* Emoji; sized to be easily understood while not overwhelming text. */
    .emoji {
        height: 20px;
        width: 20px;
    }

    /* Mentions and alert words */
    .user-mention-me :not(.silent) {
        background-color: hsl(112, 88%, 87%);
    }

    .user-group-mention,
    .user-mention {
        border-radius: 3px;
        padding: 0 0.2em;
        box-shadow: 0 0 0 1px hsl(0, 0%, 80%);
        margin-right: 2px;
        margin-left: 2px;
        white-space: nowrap;
        background: linear-gradient(
            to bottom,
            hsla(0, 0%, 0%, 0.1) 0%,
            hsla(0, 0%, 0%, 0) 100%
        );
        display: inline-block;
        margin-bottom: 1px;
    }

    .alert-word {
        background-color: hsla(102, 85%, 57%, 0.5);
    }

    /* Timestamps */
    time {
        background: hsl(0, 0%, 93%);
        border-radius: 3px;
        padding: 0 0.2em;
        box-shadow: 0 0 0 1px hsl(0, 0%, 80%);
        white-space: nowrap;
        margin-left: 2px;
        margin-right: 2px;
        display: inline-block;
        margin-bottom: 1px;
    }

    /* LaTeX styling */
    .katex-display {
        /* KaTeX sometimes overdraws its bounding box by a little, so we
           enlarge its scrolling area by stealing 3px from the margin
           of the enclosing <p>. */
        margin: -3px 0;
        padding: 3px 0;
        overflow: auto hidden;
    }

    .tex-error {
        color: hsl(0, 0%, 50%);
    }

    /* Spoiler styling */
    .spoiler-block {
        border: hsl(0, 0%, 50%) 1px solid;
        padding: 2px 8px 2px 10px;
        border-radius: 10px;
        position: relative;
        top: 1px;
        display: block;
        margin: 5px 0 15px;

        .spoiler-header {
            padding: 5px;
            font-weight: bold;
        }

        .spoiler-content {
            overflow: hidden;
            border-top: hsl(0, 0%, 50%) 0 solid;
            transition: height 0.4s ease-in-out, border-top 0.4s step-end,
                padding 0.4s step-end;
            padding: 0;
            height: 0;

            &.spoiler-content-open {
                border-top: hsl(0, 0%, 50%) 1px solid;
                transition: height 0.4s ease-in-out, border-top 0.4s step-start,
                    padding 0.4s step-start;
                padding: 5px;
                height: auto;
            }
        }

        .spoiler-button {
            float: right;
            width: 25px;
            height: 25px;

            &:hover .spoiler-arrow {
                &::before,
                &::after {
                    background-color: hsl(0, 0%, 50%);
                }
            }
        }

        .spoiler-arrow {
            float: right;
            width: 13px;
            height: 13px;
            position: relative;
            bottom: -5px;
            left: -10px;
            cursor: pointer;
            transition: 0.4s ease;
            margin-top: 2px;
            text-align: left;
            transform: rotate(45deg);

            &::before,
            &::after {
                position: absolute;
                content: "";
                display: inline-block;
                width: 12px;
                height: 3px;
                background-color: hsl(0, 0%, 83%);
                transition: 0.4s ease;
            }

            &::after {
                position: absolute;
                transform: rotate(90deg);
                top: -5px;
                left: 5px;
            }

            &.spoiler-button-open {
                transform: rotate(45deg) translate(-5px, -5px);

                &::before {
                    transform: translate(10px, 0);
                }

                &::after {
                    transform: rotate(90deg) translate(10px, 0);
                }
            }
        }
    }

    /* embedded link previews */
    .message_inline_image_title {
        font-weight: bold;
    }

    .twitter-image,
    .message_inline_image {
        position: relative;
        margin-bottom: 5px;
        margin-right: 5px;
        height: 100px;
        display: block !important;
        border: none !important;
    }

    &.rtl .twitter-image,
    &.rtl .message_inline_image {
        margin-left: unset;
        margin-right: 5px;
    }

    .twitter-tweet {
        border: 1px solid hsl(0, 0%, 87%);
        padding: 0.5em 0.75em;
        margin-bottom: 0.25em;
        word-break: break-word;
        min-height: 48px;
    }

    .twitter-avatar {
        float: left;
        width: 48px;
        height: 48px;
        margin-right: 0.75em;
    }

    .message_inline_ref {
        margin-bottom: 5px;
        margin-left: 5px;
        height: 50px;
        display: block !important;
        border: none !important;
    }

    &.rtl .message_inline_ref {
        margin-left: unset;
        margin-right: 5px;
    }

    .twitter-image img,
    .message_inline_image img,
    .message_inline_ref img {
        height: auto;
        max-height: 100%;
        float: left;
        margin-right: 10px;
    }

    .message_inline_image img {
        cursor: zoom-in;
    }

    .youtube-video img,
    .vimeo-video img,
    .embed-video img {
        cursor: pointer;
    }

    &.rtl .twitter-image img,
    &.rtl .message_inline_image img,
    &.rtl .message_inline_ref img {
        float: right;
        margin-right: unset;
        margin-left: 10px;
    }

    li .message_inline_image img {
        float: none;
    }

    .youtube-video .fa-play::before,
    .embed-video .fa-play::before {
        position: absolute;
        margin: var(--margin-top, 32px) 0 0 var(--margin-left, 45px);
        padding: 5px 8px 5px 10px;
        font-size: 12px;
        border-radius: 4px;
        background-color: hsl(0, 0%, 0%);
        color: hsl(0, 0%, 100%);
        opacity: 0.7;
        top: 0;
        left: 0;
    }

    .message_embed {
        display: block;
        position: relative;
        margin: 5px 0;
        border: none;
        border-left: 3px solid hsl(0, 0%, 93%);
        height: 80px;
        padding: 5px;
        z-index: 1;
        text-shadow: hsla(0, 0%, 0%, 0.01) 0 0 1px;

        .message_embed_title {
            padding-top: 0;
            /* to remove the spacing that the font has from the top of the container. */
            margin-top: -5px;

            font-size: 1.2em;
            line-height: normal;
        }

        .message_embed_description {
            position: relative;
            max-width: 500px;
            margin-top: 3px;

            /* to put it below the container gradient. */
            z-index: -1;
        }

        .message_embed_image {
            display: inline-block;
            width: 70px;
            height: 70px;
            background-size: cover;
            background-position: center;
        }

        .data-container {
            position: relative;
            padding: 0 5px;
            display: inline-block;
            vertical-align: top;
            max-width: calc(100% - 115px);
            max-height: 80px;
            overflow: hidden;
        }

        .data-container div {
            display: block;
            border: none;
        }

        .data-container::after {
            content: " ";
            position: absolute;
            width: 100%;
            height: 10%;
            bottom: 0;

            background: linear-gradient(
                0deg,
                hsl(0, 0%, 100%),
                transparent 100%
            );
        }
    }

    &.rtl .message_embed {
        border-left: unset;
        border-right: 3px solid hsl(0, 0%, 93%);
    }

    .message_embed > * {
        display: inherit;
        padding: 5px;
        border: none;
    }

    pre {
        &:hover .copy_codeblock,
        &:hover .code_external_link {
            visibility: visible;
        }
    }

    /* Style copy-to-clipboard button inside code blocks */
    .copy_codeblock {
        visibility: hidden;
        /* Having absolute positioning here ensures that the element
        doesn't scroll along with the code div in narrow windows */
        position: absolute;
        right: 2px;
        margin-top: -6px;
    }

    .code_external_link {
        visibility: hidden;
        position: absolute;
        right: 23px;
        margin-top: -4px;
        font-size: 1.4em;
        /* The default icon and on-hover colors are inherited from <a> tag.
        so we set our own to match the copy-to-clipbord icon */
        color: hsl(0, 0%, 47%);

        &:hover {
            color: hsl(200, 100%, 40%);
        }
    }
}

.preview_content .copy_codeblock {
    /* We avoid displaying copy_codeblock button in previews, because it
       feels odd given that you can just copy-paste the code out of
       the "edit" state.  We may change this decision when we add
       menu options for viewing the code in a coding playground. */
    display: none;
}

.informational-overlays .copy_codeblock {
    display: none;
}

.preview_content .code_external_link {
    right: 12px;
}

@media (width < $sm_min) {
    .rendered_markdown .message_embed {
        height: auto;

        .message_embed_image {
            width: 100%;
            height: 100px;
        }

        .data-container {
            display: block;
            max-width: 100%;
            margin-top: 10px;
        }
    }
}

/* Inline and block code.

TODO: It is likely that this CSS can and should be moved into the
rendered_markdown block; we just need to do further analysis to
confirm doing so won't break anything. */

code {
    /* 11.55px when body is the default 14px; this is chosen to be
       slightly above the 11.5px threshold where the height jumps by a
       pixel on most platforms. */
    font-size: 0.825em;
    unicode-bidi: embed;
    direction: ltr;
    color: hsl(0, 0%, 0%);
    white-space: pre;
}

.rendered_markdown code {
    white-space: pre-wrap;
    padding: 0 4px;
    background-color: hsl(0, 0%, 100%);
}

.codehilite {
    display: block !important;
    border: none !important;
    background: none !important;
}

pre {
    direction: ltr;
    /* code block text is a bit smaller than normal text */
    font-size: 0.825em;
    line-height: 1.4;
    white-space: pre;
    overflow-x: auto;
    word-wrap: normal;
    /* Bootstrap's default here is top: 0px, bottom: 10px */
    margin-top: 5px;
    margin-bottom: 5px;
    /* Bootstrap's default here is 9.5 on all sides */
    padding: 5px 7px 3px;
}

.rendered_markdown pre code {
    font-size: inherit;
    padding: 0;
    white-space: inherit;
}

/* Both the horizontal scrollbar in <pre/> as well as
   vertical scrollbar in the <textarea/> is styled similarly. */
.message_edit_form textarea,
pre {
    /* Ensure the horizontal scrollbar is visible on Mac */
    &::-webkit-scrollbar {
        height: 8px;
        width: 10px;
        background-color: hsla(0, 0%, 0%, 0.05);
    }

    &::-webkit-scrollbar-thumb {
        background-color: hsla(0, 0%, 0%, 0.3);
        border-radius: 20px;
        transition: all 0.2s ease;
    }

    &::-webkit-scrollbar-thumb:hover {
        background-color: hsla(0, 0%, 0%, 0.6);
    }
}

pre code {
    overflow-x: scroll;
    white-space: pre;
}

/* Style inline code inside a link
   to look more like a normal link */
a code {
    color: hsl(200, 100%, 40%);
}

a:hover code {
    color: hsl(200, 100%, 25%);
}

/* Search highlight used in both topics and rendered_markdown */
.highlight {
    background-color: hsl(51, 94%, 74%);
}