Subtle text shadow and complimentary background CSS for use in styles.less of Atom config section. Meant solely for light themes. These styles are designed to override some base syntax theme styles but in a way that should entail nice results across themes.

atom-subtle-shadows.css

// body /deep/ atom-text-editor  {
//     transform: perspective(200px) rotateX(2deg) rotateZ(-3deg);
//     transform-origin: center;
//     transform-style: preserve-3d;
// }

atom-text-editor {
    background: rgba(255,255,255,0.45);
    box-shadow:
        inset 0px 0px 200px rgba(0,50,150,0.5);
}

.gutter {
    background: none;
}

.gutter .line-number {
    border: 3px solid rgba(0,0,0,0);
    border-bottom: 3px double rgba(0,0,0,0.05);
}

atom-text-editor-minimap {
    background: rgba(255,255,255,0.85);
    box-shadow: inset 0 0 150px rgba(0,0,0,0.1);
    border: 3px double rgba(0,0,0,0.15);
}

atom-text-editor-minimap .minimap-visible-area::after {
    background: none !important;
    border-top: 1px solid darkgrey;
    border-bottom: 1px solid darkgrey;
    box-shadow: inset 0 0 50px rgba(0,0,0,0.15);
}

atom-text-editor * {
    font-weight: 900;
    text-shadow:
        1px 1px 1px white,
        2px 2px 1px white,
        3px 3px 3px currentColor;
}

atom-text-editor .selection .region,
atom-text-editor.is-focused .selection .region {
    background: antiquewhite;
    border-radius: 5px;
    box-shadow: 0 0 20px antiquewhite;
    text-shadow: none;
}

atom-text-editor .highlights,
atom-text-editor .highlights.find-result .region {
    z-index: 1;
    mix-blend-mode: color;
}

atom-text-editor .gutter .line-number.cursor-line {
    filter: contrast(80%) brightness(130%);
}

.syntax--comment {
    font-style: italic;
    text-shadow: none;
    text-shadow: 1p 1px 2px white;
    opacity: 0.75;
}

.syntax--function.syntax--method.syntax--definition::after {
    content: "fn";
    top: 1em;
    left: 1em;
    position: absolute;
    font-size: 2em;
    opacity: 0.15;
    transform: rotate(90deg);
}

atom-text-editor.editor .cursors .cursor {
    border: none;
}

atom-text-editor.editor .cursors .cursor::after {
    content: "▎";
}

atom-text-editor .line.cursor-line {
    background: none;
    box-shadow: inset 0 0 2em rgba(0,0,0,0.095);
}

atom-text-editor .line {
    border: none;
}

atom-text-editor .line::after {
    content: ".....................................................................................................................";
    position: absolute;
    left: 0px;
    color: rgba(0,0,0,0.05);
    text-shadow: none;
}

body.fullscreen .tab-bar { height: 0px; visibility: hidden; }
body.fullscreen .footer { display: none !important; }

atom-text-editor ::-webkit-scrollbar {
    display: none;
}