compiler-explorer/static/styles/themes/custom-golden-layout-themes/one-dark.scss

// based on pink.scss

$lightest: #444b53;
$lighter: #3d424d;
$light: #2c313c;
$base: #282c34;
$dark: #21252b;
$darker: #1e1f22;

// Color variables (appears count calculates by raw css)
$color0: $dark; // Appears 7 times
$color1: $base; // Appears 3 times
$color2: #e06c75; // Appears 2 times
$color3: #98c379; // Appears 2 times

$color4: #d19a66; // Appears 1 time
$color5: #61afef; // Appears 1 time
$color6: #c678dd; // Appears 1 time
$color7: #56b6c2; // Appears 1 time
$color8: #abb2bf; // Appears 1 time
$color9: #5c6370; // Appears 1 time
$color10: #e06c75; // Appears 2 time

// ".lm_dragging" is applied to BODY tag during Drag and is also directly applied to the root of the object being dragged

html[data-theme='one-dark'] {

// Entire GoldenLayout Container, if a background is set, it is visible as color of "pane header" and "splitters" (if these latest has opacity very low)
.lm_goldenlayout {
    background: $color0;
}

// Single Pane content (area in which final dragged content is contained)
.lm_content {
    background: $base;
}

// Single Pane content during Drag (style of moving window following mouse)
.lm_dragProxy {
    .lm_content {
        box-shadow: 2px 2px 4px rgba(0, 0, 0, 0.9);
    }
}

// Placeholder Container of target position
.lm_dropTargetIndicator {
    box-shadow: inset 0 0 30px $color0;
    outline: 1px dashed $color4;
    transition: all 200ms ease;

    // Inner Placeholder
    .lm_inner {
        background: $color0;
        opacity: 0.2;
    }
}

// Separator line (handle to change pane size)
.lm_splitter {
    background: $color9;
    opacity: 0.001;
    transition: opacity 200ms ease;

    &:hover, // When hovered by mouse...
  &.lm_dragging {
        background: $lighter;
        opacity: 1;
    }
}

// Pane Header (container of Tabs for each pane)
.lm_header {
    border-top: 2px solid $dark !important;
    height: 30px !important;
    user-select: none;

    &.lm_selectable {
        cursor: pointer;
    }

    // Single Tab container. A single Tab is set for each pane, a group of Tabs are contained in ".lm_header"
    .lm_tab {
        height: 26px !important;
        font-family: Arial, sans-serif;
        font-size: 12px;
        color: $color8;
        background: $base;
        margin-top: 0;
        margin-right: 0;
        padding-top: 0px;
        padding-bottom: 0px;

        .lm_title {
            padding-top: 5px;
        }

        // Close Tab Icon
        .lm_close_tab {
            width: 11px;
            height: 11px;
            background-position: center center;
            background-repeat: no-repeat;
            top: 8px;
            right: 6px;
            opacity: 0.4;

            &:hover {
                opacity: 1;
            }
        }

        // Modify Tab Icon
        .lm_modify_tab_title {
            width: 11px;
            height: 11px;
            background-position: center center;
            background-repeat: no-repeat;
            top: 8px;
            opacity: 0.4;

            &:hover {
                opacity: 1;
            }
        }

        &:hover {
            opacity: 1;
            border-bottom: 3px solid $lighter;
        }

        border-bottom: 3px solid $base;
        // If Tab is active, so if it's in foreground
        &.lm_active {
            border-bottom: 3px solid $color5;
        }
    }
}

.lm_dragProxy.lm_bottom,
.lm_stack.lm_bottom {
    .lm_header .lm_tab {
        box-shadow: 2px 2px 2px rgba(0, 0, 0, 0.3);
        &.lm_active {
            box-shadow: 0 2px 2px $color0;
        }
    }
}

// If Pane Header (container of Tabs for each pane) is selected (used only if addition of new Contents is made "by selection" and not "by drag")
.lm_selected {
    .lm_header {
        background-color: $dark;
    }
}

.lm_tab {
    &:hover, // If Tab is hovered
  &.lm_active // If Tab is active, so if it's in foreground
    {
        background: $lighter;
    }
}

// Dropdown arrow for additional tabs when too many to be displayed
.lm_header .lm_controls .lm_tabdropdown:before {
    color: #f2f2f2;
    margin-top: 3px;
}

// Pane controls (popout, maximize, minimize, close)
.lm_controls {
    // All Pane controls shares these
    > li {
        position: relative;
        background-position: center center;
        background-repeat: no-repeat;
        opacity: 0.4;
        transition: opacity 300ms ease;

        &:hover {
            opacity: 1;
        }
    }

    // Icon to PopOut Pane, so move it to a different Browser Window
    .lm_popout {
        top: 6px;
        background-image: url(data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAkAAAAJCAYAAADgkQYQAAAANUlEQVR4nI2QMQoAMAwCz5L/f9mOzZIaN0E9UDyZhaaQz6atgBHgambEJ5wBKoS0WaIvfT+6K2MIECN19MAAAAAASUVORK5CYII=);
    }

    // Icon to Maximize Pane, so it will fill the entire GoldenLayout Container
    .lm_maximise {
        top: 6px;
        background-image: url(data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAkAAAAJCAYAAADgkQYQAAAAIklEQVR4nGNkYGD4z0AAMBFSAAOETPpPlEmDUREjAxHhBABPvAQLFv3qngAAAABJRU5ErkJggg==);
    }

    // Icon to Close Pane and so remove it from GoldenLayout Container
    .lm_close {
        top: 6px;
        background-image: url(data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAkAAAAJCAYAAADgkQYQAAAAKUlEQVR4nGNgYGD4z4Af/Mdg4FKASwCnDf8JKSBoAtEmEXQTQd8RDCcA6+4Q8OvIgasAAAAASUVORK5CYII=);
    }
}

// If a specific Pane is maximized
.lm_maximised {
    // Pane Header (container of Tabs for each pane) can have different style when is Maximized
    .lm_header {
        background-color: $color0;
    }

    // Pane controls are different in Maximized Mode, especially the old Icon "Maximise" that now has a different meaning, so "Minimize" (even if CSS Class did not change)
    .lm_controls {
        .lm_maximise {
            background-image: url(data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAkAAAAJCAYAAADgkQYQAAAAJklEQVR4nGP8//8/AyHARFDFUFbEwsDAwMDIyIgzHP7//89IlEkApSkHEScJTKoAAAAASUVORK5CYII=);
        }
    }
}

.lm_transition_indicator {
    background-color: $color0;
    border: 1px dashed $color9;
}

// If a specific Pane is Popped Out, so move it to a different Browser Window, Icon to restore original position is:
.lm_popin {
    cursor: pointer;

    // Background of Icon
    .lm_bg {
        background: $color10;
        opacity: 0.3;
    }

    // Icon to Restore original position in Golden Layout Container
    .lm_icon {
        background-image: url(data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAA0AAAAJCAYAAADpeqZqAAAAWklEQVR4nJWOyw3AIAxDHcQC7L8jbwT3AlJBfNp3SiI7dtRaLSlKKeoA1oEsKSQZCEluexw8Tm3ohk+E7bnOUHUGcNh+HwbBygw4AZ7FN/Lt84p0l+yTflV8AKQyLdcCRJi/AAAAAElFTkSuQmCC);
        background-position: center center;
        background-repeat: no-repeat;
        border-left: 1px solid $color2;
        border-top: 1px solid $color2;
        opacity: 0.7;
    }

    &:hover {
        .lm_icon {
            opacity: 1;
        }
    }
}

} // End html[data-theme='one-dark']