My Trilium notes theme.

theme.css

:root {
    --theme-style: dark;

    --main-font-family: "Fira Sans";
    --main-font-size: normal;

    --tree-font-family: "Fira Sans";
    --tree-font-size: 0.9em;

    --detail-font-family: "Fira Sans";
    --detail-font-size: normal;

    --monospace-font-family: "Fira Mono";
    --monospace-font-size: 0.85em;

    --main-background-color: #333;
    --main-text-color: #ccc;
    --main-border-color: #aaa;
    --dropdown-border-color: #555;

    --accented-background-color: #555;
    --more-accented-background-color: #777;

    --button-background-color: transparent;
    --button-border-color: #ccc;
    --button-text-color: currentColor;
    --button-border-radius: 3px;
    --button-disabled-background-color: transparent;
    --button-disabled-text-color: #999;

    --primary-button-background-color: #888;
    --primary-button-text-color: white;
    --primary-button-border-color: #999;

    --muted-text-color: #bbb;

    --input-text-color: #ccc;
    --input-background-color: #333;

    --hover-item-text-color: #ccc;
    --hover-item-background-color: transparent;
    --hover-item-border-color: #aaa;

    --active-item-text-color: black;
    --active-item-background-color: #777;
    --active-item-border-color: transparent;

    --menu-text-color: white;
    --menu-background-color: #222;

    --modal-background-color: #333;
    --modal-backdrop-color: #444;

    --left-pane-background-color: #1f1f1f;
    --left-pane-text-color: #AAAAAA;

    --launcher-pane-background-color: #1f1f1f;
    --launcher-pane-text-color: #AAAAAA;

    --active-tab-background-color: #666;
    --active-tab-hover-background-color: #737373;
    --active-tab-text-color: #ccc;

    --inactive-tab-background-color: #444;
    --inactive-tab-hover-background-color: #525252;
    --inactive-tab-text-color: #bbb;

    --scrollbar-border-color: #666;
    --scrollbar-background-color: #333;
    --tooltip-background-color: #333;
    --link-color: lightskyblue;

    --mermaid-theme: dark;
}

body span.fancytree-node {
    border-radius: 3px;
    margin-left: 0.6em;
    margin-right: 0.6em;
}

body span.fancytree-expander {
    width: 1.75em;
}

body .note-detail-editable-text li {
    padding-top: 0.5em;
}

body .note-detail-editable-text {
    padding-top: 1.75em;
}

body h2 {
    margin-top: 1.5em;
    margin-bottom: 1em;
}

body .global-menu-button {
    background-image: url("http://127.0.0.1:37840/assets/v0.60.4/images/icon-black.svg");
}

body ::-webkit-calendar-picker-indicator {
    filter: invert(1);
}

body .CodeMirror {
    filter: invert(90%) hue-rotate(180deg);
}

.excalidraw.theme--dark {
    --theme-filter: invert(80%) hue-rotate(180deg) !important;
}