social/mail_full_expand/static/src/scss/mail_full_expand.scss

/* Copyright 2014-2015 Grupo ESOC <http://www.grupoesoc.es>
 * License AGPL-3.0 or later (http://www.gnu.org/licenses/agpl.html).
 */

.o_mail_thread .o_thread_message {
    .o_full_expand {
        cursor: pointer;
        opacity: 0;
        margin-right: -5px;
        padding: 4px;
    }
    
    &.o_thread_selected_message .o_full_expand {
        opacity: 0.6;
    }
    
    &:hover {
        .o_full_expand {
            opacity: 0.6;
            &:hover {
                opacity: 1;
            }
        }
    }
}