[data-gesso-btn] {
    /* Default Background */
    background-color: $color-1ary;
    
    /* Font */
    color: $color-white;
    text-align: center;
    
    /* Margins and Padding */
    margin: 0;
    padding: 0.25em 1em 0.25em 1em;
    
    /* Borders */
    outline: none;
    border: none;
    border-radius: $border-radius;
    
    /* Cursor */
    cursor: pointer;
    
    /* Disable text selection */
    -webkit-user-select: none;
    -moz-user-select: none;
    -ms-user-select: none;
}

[data-gesso-btn]:active {
    background-color: $color-1ary-shadow;
}

[data-gesso-btn]:disabled {
    background-color: $color-disabled;
}

[data-gesso-btn] [data-gesso-icon] {
    padding-right: 0.5em;
}
[data-gesso-btn] {
    /* Default Background */
    background-color: $color-1ary;
    
    /* Font */
    color: $color-white;
    text-align: center;
    
    /* Margins and Padding */
    margin: 0;
    padding: 0.25em 1em 0.25em 1em;
    
    /* Borders */
    outline: none;
    border: none;
    border-radius: $border-radius;
    
    /* Cursor */
    cursor: pointer;
    
    /* Disable text selection */
    -webkit-user-select: none;
    -moz-user-select: none;
    -ms-user-select: none;
}

[data-gesso-btn]:active {
    background-color: $color-1ary-shadow;
}

[data-gesso-btn]:disabled {
    background-color: $color-disabled;
}

[data-gesso-btn] > [data-gesso-icon] {
    padding-right: 0.5em;
}
Make the rule affect only direct children.
Make the rule affect only direct children.