button {
    padding: 0.25rem;
    vertical-align: baseline;
    align: center;
    border-radius: 0.05em;
}

vertical-align has no effect on this element since it’s not an inline or table-cell element.

Try adding display:inline or display:table-cell

display: inline
vertical-align: baseline

button {
    width: (x)px where x is odd;
    height: (x)px;
    padding: 0px;
    box-sizing: content-box;
}

    button::before, button::after {
        position: absolute;
        height: (x + 2*n)px where n is integer;
        width: 1px;
        top: (-n)px;
        left: int(x/2)px;
        content: "";
        background-color: black;
    }

    button::before {
        transform: rotate(-45deg);
    }

    button::after {
        transform: rotate(45deg);
    }

        private bool TryStoreLockedProject(IVBProject project)
        {
            if (!project.TryGetFullPath(out var path))
            {
                _logger.Warn("Path of locked project could not be read.");
            }

            var projectName = project.Name;
            var projectId = QualifiedModuleName.GetProjectId(projectName, path);

            _lockedProjects.Add(projectId, project);
            return true;
        }