:root
{
    --left-nav-font-size: var(--left-tool-nav-font-size);
    --left-nav-logo-size: 20px;
    --left-nav-text-colour: var(--text-colour);
}

#LeftNav
{
    position: relative;
    display: flex;
    height: 100vh;
    row-gap: var(--post-font-size);
    flex-direction: column;
}

#PostNav
{
    flex-grow: 0;
    flex-shrink: 0;
    flex-basis: 40%;
    display: flex;
    flex-direction: column;
    border-top: 1px solid var(--left-tool-nav-border-colour);
    color: var(--left-tool-nav-text-colour);
    font-family: var(--post-font-family);
    transition: opacity 0.5s ease, transform 0.5s ease;
    overflow-y: hidden;
    z-index: var(--post-nav-zindex);
    height: 100vh;
}

#PostNav.FadeAwayOnFocusOut
{
    opacity: 0.2;
}

#PostNav.FadeAwayOnFocusOut:hover
{
    opacity: 1;
}

#MainTitle
{
    font-family: "Lato";
    text-align: center;
    text-decoration: underline;
    text-decoration-color: var(--left-tool-nav-text-accent-colour);
    text-underline-offset: 8px;
    text-decoration-thickness: 6px;
    margin-bottom: 20px;
    font-size: 40px;
}

#TOC
{
    position: relative;
    flex-grow: 1;
    overflow-y: auto;
    max-height: 90%;
    min-height: 10%;
    margin-top: 0px;
    margin-bottom: 0px;
}

#TOCContainer
{
    padding-left: 10px;
}

#LeftNavBody
{
    flex-grow: 1;
    overflow: auto;
}

#PostNav .Placeholder
{
    background: linear-gradient(135deg, var(--darker-than-background-colour) 0%,
                                       var(--darker-than-background-colour) 50%,
                                       var(--background-colour) 60%,
                                       var(--darker-than-background-colour) 70%,
                                       var(--darker-than-background-colour));
    background-size: 200% 200%;
    margin-bottom: calc(0.5 * var(--post-font-size));
    margin-right: var(--post-font-size);
    height: var(--post-font-size);
    border-radius: var(--post-font-size);
}

#PostNav li
{
    list-style-type: none;
    list-style-position: inside;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
    padding-right: 5px;
    padding-top: 5px;
    padding-bottom: 5px;
    padding-left: 30px;
}

#TOC > li
{
    font-size: var(--left-nav-font-size);
    padding-right: 5px;
}

#TOC > li:hover, #TOC > li.active
{
    color: var(--left-tool-nav-text-accent-colour);
    font-weight: 400;
}

#TOC > li:hover > .CollapseLogo > svg path, #TOC > li.active > .CollapseLogo > svg path,
#TOC > li:hover > .HeadingLogo > svg path, #TOC > li.active > .HeadingLogo > svg path
{
    fill: var(--left-tool-nav-text-accent-colour);
}

#PostNav li:hover
{
    cursor: pointer;
}

#PostNav li ul
{
    overflow-x: auto;
}

#TOC li:hover li, #TOC > li.active li
{
    color: var(--left-nav-active-logo-colour);
}

#PostNav li li:hover
{
    font-weight: bold;
}

#PostNav li.active.NoChild
{
    text-decoration: underline;
}

/* TOC */

#TOCLabel
{
    padding-top: var(--post-font-size);
    padding-left: var(--post-font-size);
    padding-bottom: calc(0.25 * var(--post-font-size));
    margin: 0px;
    color: var(--left-tool-nav-text-accent-colour);
    font-size: var(--left-nav-font-size);
}

#TOC
{
    padding-inline-start: var(--post-font-size);
    padding-bottom: var(--post-font-size);
    padding-left: calc(0.5 * var(--post-font-size));
}

#TOC .Placeholder
{
    margin-left: calc(0.5 * var(--post-font-size));
}

#TOC li:not(.Placeholder)
{
    list-style-type: none;
    padding-left: calc(0.5 * var(--post-font-size));
}

#TOC ul
{
    border-left: 1px solid var(--left-tool-nav-text-colour);
    margin-left: calc(0.5 * var(--post-font-size));
    padding-left: calc(0.25 * var(--post-font-size));
}

#TOC ul.active
{
    border-left: 3px solid var(--left-tool-nav-text-accent-colour);
    padding-left: calc(0.25 * var(--post-font-size) - 2px);
}

#TOC > li.NoChild:hover
{
    color: var(--left-tool-nav-text-accent-colour);
}

.CollapseLogo, .HeadingLogo
{
    display: inline-block;
    position: relative;
    box-sizing: content-box;
    width: calc(0.6 * var(--post-font-size));
    height: calc(0.6 * var(--post-font-size));
    margin: calc(0.2 * var(--post-font-size));
    margin-right: calc(0.45 * var(--post-font-size));
}

#TOC li .CollapseLogo svg, #TOC li .HeadingLogo svg
{
    position: absolute;
    top: 0px;
    left: 0px;
}

.CollapseLogo svg path, .HeadingLogo svg path
{
    fill: var(--text-colour);
}

#PostNav li.active li
{
    text-decoration: none;
}

#PostNav > ul
{
    border-left: none;
}