$padding-basis: 0.75em;

.d-toc-main {
  display: none;
  width: 225px;
  border-left: 1px solid var(--primary-low);
  box-sizing: border-box;
  a {
    display: block;
    padding: 0.15em 0;
    color: var(--primary-medium);
    &.scroll-to-bottom {
      padding-left: $padding-basis;
    }
  }
  #d-toc {
    max-height: calc(100vh - 4.5em - var(--header-offset));
    padding-bottom: 0.5em;
    overflow: auto;
    ul {
      list-style-type: none;
      margin: 0;
      padding: 0;
    }
    li.d-toc-item {
      margin: 0;
      padding: 0;
      padding-left: $padding-basis;
      line-height: 1.6em;
      > ul {
        max-height: 0;
        overflow: hidden;
        opacity: 0.5;
        transition: opacity 0.3s ease-in-out, max-height 0.3s ease-in-out;
      }
      &.active,
      .d-toc-wrapper.overlay & {
        ul {
          max-height: 50em;
          overflow: visible;
          opacity: 1;
        }
      }
      &.direct-active > a {
        position: relative;
        color: var(--primary);
        &:before {
          content: "";
          width: 1px;
          margin-top: -1px;
          background-color: var(--tertiary);
          position: absolute;
          height: 100%;
        }
      }
    }

    > ul > li > ul {
      font-size: var(--font-down-1);
      li.direct-active > a:before {
        // it's odd that we need this
        margin-left: -1px;
      }
      ul {
        margin-bottom: 0.5em;
      }
    }
  }
}

// active line marker
$selector: "> ul > li.direct-active > a:before";
$sub: "> ul > li";
$map: (
  "left": "html:not(.rtl)",
  "right": "html.rtl",
);

/*
// loop below generates styling for non-RTL and RTL
// Example:
html:not(.rtl) SELECTOR {
    left: -.75em
}
html.rtl SELECTOR {
    right: -.75em
}
*/
@each $prop, $parent in $map {
  #{$parent} #d-toc {
    #{$selector} {
      #{$prop}: (-$padding-basis);
    }
    #{$sub} #{$selector} {
      #{$prop}: (-$padding-basis) * 2;
    }
    #{$sub} #{$sub} #{$selector} {
      #{$prop}: (-$padding-basis) * 3;
    }
    #{$sub} #{$sub} #{$sub} #{$selector} {
      #{$prop}: (-$padding-basis) * 4;
    }
    #{$sub} #{$sub} #{$sub} #{$sub} #{$selector} {
      #{$prop}: (-$padding-basis) * 5;
    }
    #{$sub} #{$sub} #{$sub} #{$sub} #{$sub} #{$selector} {
      #{$prop}: (-$padding-basis) * 6;
    }
  }
}
// END active line marker

.d-toc-mini,
a.d-toc-close {
  display: none;
}

.d-toc-timeline-visible {
  .d-toc-main,
  .d-toc-mini {
    display: block;
  }
  // overlayed timeline (on mobile and narrow screens)
  .topic-navigation.with-topic-progress {
    .d-toc-wrapper {
      position: fixed;
      margin-top: 0.25em;
      height: calc(100vh - 50px - var(--header-offset));
      opacity: 0.5;
      right: -100vw;
      top: var(--header-offset);
      width: 75vw;
      max-width: 350px;
      background-color: var(--secondary);
      box-shadow: shadow("dropdown");
      z-index: z("modal", "overlay");
      transition: all 0.2s ease-in-out;
      .d-toc-main {
        width: 100%;
        padding: 0.5em;
        height: 100%;
        #d-toc {
          max-height: calc(100% - 3em);
        }
      }
      &.overlay {
        right: 0;
        width: 75vw;
        opacity: 1;
        .d-toc-main #d-toc li.d-toc-item ul {
          transition: none;
        }
      }

      a.scroll-to-bottom,
      a.d-toc-close {
        display: inline-block;
        padding: 0.5em;
      }

      .d-toc-icons {
        text-align: right;
      }
    }
  }

  // core overrides when timeline is active
  .timeline-container,
  #topic-progress {
    display: none;
  }
  .container.posts .topic-navigation.with-topic-progress {
    align-self: start;
  }
}

// RTL Support
.rtl {
  .d-toc-main {
    border-left: none;
    border-right: 1px solid var(--primary-low);

    #d-toc li.d-toc-item,
    a.scroll-to-bottom {
      padding-left: 0;
      padding-right: $padding-basis;
    }
  }

  .d-toc-timeline-visible .topic-navigation.with-topic-progress .d-toc-wrapper {
    right: unset;
    left: -100vw;
    &.overlay {
      right: unset;
      left: 0;
    }
  }
}

// Composer preview notice
.edit-title .d-editor-preview [data-theme-toc] {
  background: var(--tertiary);
  color: var(--secondary);
  border-top: 2px solid var(--secondary);
  position: sticky;
  top: 0;
  height: 30px;
  display: flex;
  align-items: center;
  justify-content: center;
  &:before {
    content: "#{$composer_toc_text}";
  }
}