[IMP] mass_mailing: review theme style location and convention

* Use the theme class selector as root for the less file
-> Allow to style the editor as applied to the body
-> Split in editor/color/layout/snippets

* Create an assets to contain all mm themes so that the compilation is
made by the odoo system, and allow minification and variable sharing
between themes
-> Remove css files

* Reformat the LESS files content

11 files changed, 216 insertions, 910 deletions

diff --git a/addons/mass_mailing/static/src/css/compiled/theme_airmail.css b/addons/mass_mailing/static/src/css/compiled/theme_airmail.css
deleted file mode 100644
index 23ad8330e7c..00000000000
--- a/addons/mass_mailing/static/src/css/compiled/theme_airmail.css
+++ /dev/null
@@ -1,168 +0,0 @@
-.o_layout.o_airmail_theme {
-  background-color: #EAECED;
-}
-.o_layout.o_airmail_theme .o_mail_wrapper {
-  background: rgba(0, 0, 0, 0);
-  background: transparent;
-  border: none;
-}
-.o_layout.o_airmail_theme .o_mail_snippet_general {
-  background-color: white;
-  color: black;
-}
-.o_layout.o_airmail_theme .o_mail_snippet_general .btn.btn-primary {
-  color: white;
-  background-color: #FB3C6B;
-}
-.o_layout.o_airmail_theme .o_mail_snippet_general a,
-.o_layout.o_airmail_theme .o_mail_snippet_general .o_mail_link {
-  color: #fa2358;
-}
-.o_layout.o_airmail_theme .o_mail_snippet_general .bg-beta {
-  background-color: #FB3C6B;
-}
-.o_layout.o_airmail_theme .o_mail_snippet_general .bg-beta .btn.btn-primary {
-  color: white;
-  background-color: #a17e92;
-}
-.o_layout.o_airmail_theme .o_mail_snippet_general .bg-beta h1,
-.o_layout.o_airmail_theme .o_mail_snippet_general .bg-beta h2,
-.o_layout.o_airmail_theme .o_mail_snippet_general .bg-beta h3,
-.o_layout.o_airmail_theme .o_mail_snippet_general .bg-beta h4,
-.o_layout.o_airmail_theme .o_mail_snippet_general .bg-beta h5,
-.o_layout.o_airmail_theme .o_mail_snippet_general .bg-beta h6,
-.o_layout.o_airmail_theme .o_mail_snippet_general .bg-beta .h1,
-.o_layout.o_airmail_theme .o_mail_snippet_general .bg-beta .h2,
-.o_layout.o_airmail_theme .o_mail_snippet_general .bg-beta .h3,
-.o_layout.o_airmail_theme .o_mail_snippet_general .bg-beta .h4,
-.o_layout.o_airmail_theme .o_mail_snippet_general .bg-beta .h5,
-.o_layout.o_airmail_theme .o_mail_snippet_general .bg-beta .h6 {
-  color: white;
-}
-.o_layout.o_airmail_theme .o_mail_snippet_general .text-beta {
-  color: #FB3C6B;
-}
-.o_layout.o_airmail_theme .o_mail_snippet_general .bg-delta {
-  background-color: #a17e92;
-}
-.o_layout.o_airmail_theme .o_mail_wrapper > div {
-  margin-bottom: 16px;
-}
-.o_layout.o_airmail_theme .o_mail_wrapper .o_mail_block_header_social,
-.o_layout.o_airmail_theme .o_mail_wrapper .o_mail_block_header_text_social,
-.o_layout.o_airmail_theme .o_mail_wrapper .o_mail_block_header_logo {
-  margin-bottom: 0;
-}
-.o_layout.o_airmail_theme .o_mail_wrapper .o_mail_block_header_social .o_mail_snippet_general,
-.o_layout.o_airmail_theme .o_mail_wrapper .o_mail_block_header_text_social .o_mail_snippet_general,
-.o_layout.o_airmail_theme .o_mail_wrapper .o_mail_block_header_logo .o_mail_snippet_general {
-  background: rgba(0, 0, 0, 0);
-  background: transparent;
-}
-.o_layout.o_airmail_theme .o_mail_wrapper .o_mail_block_header_social .o_mail_h_padding,
-.o_layout.o_airmail_theme .o_mail_wrapper .o_mail_block_header_text_social .o_mail_h_padding,
-.o_layout.o_airmail_theme .o_mail_wrapper .o_mail_block_header_logo .o_mail_h_padding {
-  padding-left: 0;
-  padding-right: 0;
-}
-.o_layout.o_airmail_theme .o_mail_wrapper .o_mail_block_header_social .o_mail_header_social,
-.o_layout.o_airmail_theme .o_mail_wrapper .o_mail_block_header_text_social .o_mail_header_social,
-.o_layout.o_airmail_theme .o_mail_wrapper .o_mail_block_header_logo .o_mail_header_social {
-  margin-right: 0px;
-}
-.o_layout.o_airmail_theme .o_mail_wrapper .o_mail_block_header_social .o_mail_header_social a,
-.o_layout.o_airmail_theme .o_mail_wrapper .o_mail_block_header_text_social .o_mail_header_social a,
-.o_layout.o_airmail_theme .o_mail_wrapper .o_mail_block_header_logo .o_mail_header_social a {
-  color: #7c898f;
-}
-.o_layout.o_airmail_theme .o_mail_block_event {
-  margin-left: 0;
-  margin-right: 0;
-}
-.o_layout.o_airmail_theme .o_mail_block_footer_separator {
-  margin-left: 0;
-  margin-right: 0;
-}
-.o_layout.o_airmail_theme .o_mail_block_image .o_mail_h_padding {
-  padding: 0;
-}
-.o_layout.o_airmail_theme .o_mail_block_image .o_mail_h_padding .o_mail_col_mv {
-  padding-left: 20px;
-  padding-right: 20px;
-}
-.o_layout.o_airmail_theme .o_mail_block_image .o_mail_h_padding > img {
-  padding: 0;
-  margin-bottom: 15px;
-}
-.o_layout.o_airmail_theme .o_mail_block_footer_separator .o_mail_snippet_general {
-  background: rgba(0, 0, 0, 0);
-  background: transparent;
-}
-.o_layout.o_airmail_theme .o_mail_block_footer_separator .o_mail_snippet_general .separator {
-  height: 3px;
-  background-color: #cfd3d5;
-  border-bottom: 2px solid #f7f7f7;
-}
-.o_layout.o_airmail_theme .o_mail_block_two_cols table,
-.o_layout.o_airmail_theme .o_mail_block_three_cols table {
-  width: 110%;
-  max-width: 620px;
-  margin: auto -10px;
-}
-.o_layout.o_airmail_theme .o_mail_block_two_cols .o_mail_snippet_general,
-.o_layout.o_airmail_theme .o_mail_block_three_cols .o_mail_snippet_general {
-  background: rgba(0, 0, 0, 0);
-  background: transparent;
-}
-.o_layout.o_airmail_theme .o_mail_block_two_cols .o_mail_col_container,
-.o_layout.o_airmail_theme .o_mail_block_three_cols .o_mail_col_container {
-  padding: 0 0 20px;
-  margin: 0 10px;
-  border-top: 1px solid #e6e6e6;
-  border-bottom: 1px solid #dce0e1;
-  background-color: white;
-}
-.o_layout.o_airmail_theme .o_mail_block_two_cols .o_mail_col_container > *,
-.o_layout.o_airmail_theme .o_mail_block_three_cols .o_mail_col_container > * {
-  padding: 0 20px;
-}
-.o_layout.o_airmail_theme .o_mail_block_two_cols .o_mail_col_container img,
-.o_layout.o_airmail_theme .o_mail_block_three_cols .o_mail_col_container img {
-  padding: 0!important;
-}
-.o_layout.o_airmail_theme .o_mail_block_footer_tag_line table.o_mail_h_padding {
-  padding-left: 0;
-  padding-right: 0;
-}
-.o_layout.o_airmail_theme .o_mail_block_image_text .o_mail_img_container {
-  padding: 0;
-}
-.o_layout.o_airmail_theme .o_mail_block_text_image .o_mail_img_container {
-  padding: 0;
-}
-.o_layout.o_airmail_theme .o_mail_block_footer_social .o_mail_snippet_general {
-  background: rgba(0, 0, 0, 0);
-  background: transparent;
-  margin-top: 30px;
-  border-top: 1px solid #cfd3d5;
-}
-.o_layout.o_airmail_theme .o_mail_block_footer_social .o_mail_footer_social {
-  border: none;
-}
-.o_layout.o_airmail_theme .o_mail_block_footer_social .o_mail_footer_social a {
-  color: #7c898f;
-}
-.o_layout.o_airmail_theme .o_mail_block_footer_social .o_mail_footer_links a {
-  color: #7c898f;
-}
-.o_layout.o_airmail_theme .o_mail_block_footer_social .o_mail_footer_copy {
-  font-weight: bold;
-  font-size: 9px;
-  color: #98a1a6;
-}
-.o_layout.o_airmail_theme .o_mail_block_footer_social.o_mail_footer_social_left .o_mail_footer_description {
-  padding-left: 0;
-}
-.o_layout.o_airmail_theme .o_mail_block_footer_social.o_mail_footer_social_left .o_mail_footer_social {
-  padding-right: 0;
-}
diff --git a/addons/mass_mailing/static/src/css/compiled/theme_default.css b/addons/mass_mailing/static/src/css/compiled/theme_default.css
deleted file mode 100644
index d68c8183572..00000000000
--- a/addons/mass_mailing/static/src/css/compiled/theme_default.css
+++ /dev/null
@@ -1,220 +0,0 @@
-#web_editor_inside_iframe #wrapwrap > main #editable_area {
-  background-color: transparent;
-}
-.o_layout {
-  font-family: -apple-system, "HelveticaNeue", "Helvetica Neue", Helvetica, Arial, "Lucida Grande", sans-serif;
-  color: #797979;
-  overflow: hidden;
-  width: 100%;
-  min-height: 100%;
-  background-color: #f5f5f5;
-  padding-bottom: 20px;
-}
-.o_layout .o_mail_wrapper {
-  width: 100%;
-  max-width: 600px;
-  margin: auto;
-  border: 1px solid #f0f0f0;
-  background-color: #ffffff;
-}
-.o_mail_snippet_general {
-  width: 100%;
-  max-width: 600px;
-  margin: 0 auto;
-}
-.o_mail_snippet_general h1,
-.o_mail_snippet_general h2,
-.o_mail_snippet_general h3,
-.o_mail_snippet_general h4,
-.o_mail_snippet_general h5,
-.o_mail_snippet_general h6,
-.o_mail_snippet_general .h1,
-.o_mail_snippet_general .h2,
-.o_mail_snippet_general .h3,
-.o_mail_snippet_general .h4,
-.o_mail_snippet_general .h5,
-.o_mail_snippet_general .h6 {
-  color: #464646;
-}
-.o_mail_snippet_general .btn.btn-primary {
-  -webkit-user-select: none;
-  color: #ffffff;
-  border: none;
-  text-decoration: none;
-  font-weight: normal;
-  font-family: -apple-system, "HelveticaNeue", "Helvetica Neue", Helvetica, Arial, "Lucida Grande", sans-serif;
-  cursor: pointer;
-  border-radius: 2px;
-  background-color: #706482;
-}
-.o_mail_snippet_general a,
-.o_mail_snippet_general .btn.btn-link {
-  color: #645974;
-  font-weight: bold;
-  text-decoration: none !important;
-}
-.o_mail_snippet_general a:hover,
-.o_mail_snippet_general .btn.btn-link:hover,
-.o_mail_snippet_general a:focus,
-.o_mail_snippet_general .btn.btn-link:focus,
-.o_mail_snippet_general a:active,
-.o_mail_snippet_general .btn.btn-link:active {
-  text-decoration: none !important;
-}
-.o_mail_snippet_general img {
-  width: 100%;
-  max-width: 100%;
-  height: auto;
-}
-.o_mail_snippet_general .separator {
-  height: 2px;
-  background-color: #f5f5f5;
-}
-.o_mail_snippet_general .bg-beta {
-  background-color: #706482;
-  color: #ffffff;
-}
-.o_mail_snippet_general .bg-beta h1,
-.o_mail_snippet_general .bg-beta h2,
-.o_mail_snippet_general .bg-beta h3,
-.o_mail_snippet_general .bg-beta h4,
-.o_mail_snippet_general .bg-beta h5,
-.o_mail_snippet_general .bg-beta h6,
-.o_mail_snippet_general .bg-beta .h1,
-.o_mail_snippet_general .bg-beta .h2,
-.o_mail_snippet_general .bg-beta .h3,
-.o_mail_snippet_general .bg-beta .h4,
-.o_mail_snippet_general .bg-beta .h5,
-.o_mail_snippet_general .bg-beta .h6 {
-  color: #ffffff;
-}
-.o_mail_snippet_general .text-beta {
-  color: #706482;
-}
-.o_mail_snippet_general .bg-delta {
-  background-color: #87a6b5;
-}
-.o_mail_snippet_general .bg-gray-lighter {
-  background-color: #f5f5f5;
-}
-.o_mail_block_header_social .o_mail_logo_container img,
-.o_mail_block_header_text_social .o_mail_logo_container img,
-.o_mail_block_header_logo .o_mail_logo_container img {
-  width: auto;
-}
-.o_mail_block_header_social .o_mail_header_social,
-.o_mail_block_header_text_social .o_mail_header_social,
-.o_mail_block_header_logo .o_mail_header_social {
-  margin-right: 20px;
-}
-.o_mail_block_header_text_social h3 {
-  font-weight: bold;
-}
-.o_mail_block_steps {
-  background-color: #f5f5f5;
-}
-.o_mail_block_two_cols,
-.o_mail_block_three_cols {
-  font-size: small;
-}
-.o_mail_block_two_cols .o_mail_col_container,
-.o_mail_block_three_cols .o_mail_col_container {
-  padding: 10px 20px;
-}
-.o_mail_block_two_cols .o_mail_col_container h4,
-.o_mail_block_three_cols .o_mail_col_container h4 {
-  margin-top: 15px;
-}
-.o_mail_block_image_text,
-.o_mail_block_text_image {
-  font-size: small;
-}
-.o_mail_block_event {
-  margin-left: 20px;
-  margin-right: 20px;
-}
-.o_mail_block_event .o_mail_snippet_general {
-  background: #f0f0f0;
-}
-.o_mail_block_footer_separator {
-  margin-left: 20px;
-  margin-right: 20px;
-}
-.o_mail_block_comparison_table .separator {
-  height: 1px;
-  background-color: #cfcfcf;
-}
-.o_mail_block_discount2 .o_code {
-  padding: 5px 10px;
-  background: #f5f5f5;
-  border-radius: 3px;
-  font-family: monospace;
-}
-.o_mail_block_footer_social .o_mail_table_styles {
-  border-top: 2px solid #f5f5f5;
-  padding-top: 20px;
-}
-.o_mail_block_footer_social .o_mail_footer_links {
-  padding-top: 10px;
-  padding-bottom: 10px;
-}
-.o_mail_block_footer_social .o_mail_footer_links .btn-link {
-  padding: 0;
-  font-size: 12px;
-}
-.o_mail_block_footer_social .o_mail_footer_copy {
-  font-size: 9px;
-  font-weight: bold;
-  color: #939393;
-}
-.o_mail_block_footer_social.o_mail_footer_social_center .o_mail_footer_social,
-.o_mail_block_footer_social.o_mail_footer_social_center .o_mail_footer_links,
-.o_mail_block_footer_social.o_mail_footer_social_center .o_mail_footer_copy {
-  text-align: center;
-}
-.o_mail_block_footer_social.o_mail_footer_social_left .o_mail_footer_description {
-  padding-left: 20px;
-}
-.o_mail_block_footer_social.o_mail_footer_social_left .o_mail_footer_social {
-  padding-right: 20px;
-  text-align: right;
-  vertical-align: top;
-}
-.o_mail_block_footer_social.o_mail_footer_social_left .o_mail_footer_social .btn-link {
-  padding: 0;
-  font-size: 12px;
-}
-.o_mail_display_coupon {
-  font-size: 50px;
-  line-height: 1;
-}
-/* ======================== MISC ====================== */
-.o_mail_h_padding {
-  padding-left: 20px;
-  padding-right: 20px;
-}
-.o_mail_v_padding {
-  padding-top: 20px;
-  padding-bottom: 20px;
-}
-.o_mail_no_margin {
-  margin: 0;
-}
-.o_mail_no_margin.o_mail_display_coupon {
-  line-height: 1.1;
-}
-.o_mail_table_styles {
-  width: 100%;
-  border-collapse: separate;
-}
-@media screen and (max-width: 480px) {
-  .o_mail_col_mv {
-    display: block!important;
-    max-width: 480px !important;
-    width: 100%!important;
-  }
-  .o_mail_table_styles {
-    max-width: 480px !important;
-    width: 100%!important;
-  }
-}
diff --git a/addons/mass_mailing/static/src/css/compiled/theme_newsletter.css b/addons/mass_mailing/static/src/css/compiled/theme_newsletter.css
deleted file mode 100644
index 8761fbffe0f..00000000000
--- a/addons/mass_mailing/static/src/css/compiled/theme_newsletter.css
+++ /dev/null
@@ -1,18 +0,0 @@
-.o_layout.o_newsletter_theme .o_mail_snippet_general .btn.btn-primary {
-  color: #ffffff;
-  background-color: #1cc1a9;
-}
-.o_layout.o_newsletter_theme .o_mail_snippet_general a,
-.o_layout.o_newsletter_theme .o_mail_snippet_general .btn.btn-link {
-  color: #19ab96;
-}
-.o_layout.o_newsletter_theme .o_mail_snippet_general .bg-beta {
-  background-color: #906784;
-  color: #ffffff;
-}
-.o_layout.o_newsletter_theme .o_mail_snippet_general .text-beta {
-  color: #906784;
-}
-.o_layout.o_newsletter_theme .o_mail_snippet_general .bg-delta {
-  background-color: #87a6b5;
-}
diff --git a/addons/mass_mailing/static/src/css/compiled/theme_resto.css b/addons/mass_mailing/static/src/css/compiled/theme_resto.css
deleted file mode 100644
index c4b5fa45d16..00000000000
--- a/addons/mass_mailing/static/src/css/compiled/theme_resto.css
+++ /dev/null
@@ -1,114 +0,0 @@
-#web_editor_inside_iframe.o_resto_theme {
-  background-color: #f0ede0;
-}
-.o_layout.o_resto_theme {
-  background-color: #f0ede0;
-}
-.o_layout.o_resto_theme .o_mail_wrapper {
-  border: none;
-  background-color: transparent;
-}
-.o_layout.o_resto_theme .o_mail_snippet_general {
-  background: rgba(0, 0, 0, 0);
-  background: transparent;
-  color: #712b22;
-}
-.o_layout.o_resto_theme .o_mail_snippet_general .btn.btn-primary {
-  color: #ffffff;
-  background-color: #E96D1F;
-}
-.o_layout.o_resto_theme .o_mail_snippet_general a,
-.o_layout.o_resto_theme .o_mail_snippet_general .o_mail_link {
-  font-weight: normal;
-  color: #d96115;
-}
-.o_layout.o_resto_theme .o_mail_snippet_general .bg-beta {
-  background-color: #795745;
-  color: #ffffff;
-}
-.o_layout.o_resto_theme .o_mail_snippet_general .bg-beta h1,
-.o_layout.o_resto_theme .o_mail_snippet_general .bg-beta h2,
-.o_layout.o_resto_theme .o_mail_snippet_general .bg-beta h3,
-.o_layout.o_resto_theme .o_mail_snippet_general .bg-beta h4,
-.o_layout.o_resto_theme .o_mail_snippet_general .bg-beta h5,
-.o_layout.o_resto_theme .o_mail_snippet_general .bg-beta h6,
-.o_layout.o_resto_theme .o_mail_snippet_general .bg-beta .h1,
-.o_layout.o_resto_theme .o_mail_snippet_general .bg-beta .h2,
-.o_layout.o_resto_theme .o_mail_snippet_general .bg-beta .h3,
-.o_layout.o_resto_theme .o_mail_snippet_general .bg-beta .h4,
-.o_layout.o_resto_theme .o_mail_snippet_general .bg-beta .h5,
-.o_layout.o_resto_theme .o_mail_snippet_general .bg-beta .h6 {
-  color: #ffffff;
-}
-.o_layout.o_resto_theme .o_mail_snippet_general .text-beta {
-  color: #795745;
-}
-.o_layout.o_resto_theme .o_mail_snippet_general .bg-delta {
-  background-color: #E96D1F;
-  color: #ffffff;
-}
-.o_layout.o_resto_theme .o_mail_snippet_general .bg-delta h1,
-.o_layout.o_resto_theme .o_mail_snippet_general .bg-delta h2,
-.o_layout.o_resto_theme .o_mail_snippet_general .bg-delta h3,
-.o_layout.o_resto_theme .o_mail_snippet_general .bg-delta h4,
-.o_layout.o_resto_theme .o_mail_snippet_general .bg-delta h5,
-.o_layout.o_resto_theme .o_mail_snippet_general .bg-delta h6,
-.o_layout.o_resto_theme .o_mail_snippet_general .bg-delta .h1,
-.o_layout.o_resto_theme .o_mail_snippet_general .bg-delta .h2,
-.o_layout.o_resto_theme .o_mail_snippet_general .bg-delta .h3,
-.o_layout.o_resto_theme .o_mail_snippet_general .bg-delta .h4,
-.o_layout.o_resto_theme .o_mail_snippet_general .bg-delta .h5,
-.o_layout.o_resto_theme .o_mail_snippet_general .bg-delta .h6 {
-  color: #ffffff;
-}
-.o_layout.o_resto_theme .o_mail_snippet_general .text-delta {
-  color: #d96115;
-}
-.o_layout.o_resto_theme .o_mail_snippet_general .separator {
-  background-color: #b08974;
-}
-.o_layout.o_resto_theme h1,
-.o_layout.o_resto_theme h2,
-.o_layout.o_resto_theme h3,
-.o_layout.o_resto_theme h4,
-.o_layout.o_resto_theme h5,
-.o_layout.o_resto_theme h6,
-.o_layout.o_resto_theme .h1,
-.o_layout.o_resto_theme .h2,
-.o_layout.o_resto_theme .h3,
-.o_layout.o_resto_theme .h4,
-.o_layout.o_resto_theme .h5,
-.o_layout.o_resto_theme .h6 {
-  color: #594032;
-  font-weight: bold;
-}
-.o_layout.o_resto_theme .o_mail_block_header_social .o_mail_snippet_general,
-.o_layout.o_resto_theme .o_mail_block_header_text_social .o_mail_snippet_general,
-.o_layout.o_resto_theme .o_mail_block_header_logo .o_mail_snippet_general {
-  border-bottom: 5px solid #E96D1F;
-}
-.o_layout.o_resto_theme .o_mail_block_header_social .o_mail_header_social a,
-.o_layout.o_resto_theme .o_mail_block_header_text_social .o_mail_header_social a,
-.o_layout.o_resto_theme .o_mail_block_header_logo .o_mail_header_social a {
-  color: #E96D1F;
-}
-.o_layout.o_resto_theme .o_mail_block_steps {
-  border-top: 2px solid #E96D1F;
-  background: #ffffff;
-}
-.o_layout.o_resto_theme .o_mail_block_event .o_mail_snippet_general {
-  background: #fafafa;
-}
-.o_layout.o_resto_theme .o_mail_block_header_social,
-.o_layout.o_resto_theme .o_mail_block_header_text_social,
-.o_layout.o_resto_theme .o_mail_block_header_logo,
-.o_layout.o_resto_theme .o_mail_block_steps,
-.o_layout.o_resto_theme .o_mail_block_event,
-.o_layout.o_resto_theme .o_mail_block_banner {
-  margin-left: 20px;
-  margin-right: 20px;
-}
-.o_layout.o_resto_theme .o_mail_block_footer_social .o_mail_table_styles {
-  border-top: 2px solid #b08974;
-  padding-top: 20px;
-}
diff --git a/addons/mass_mailing/static/src/css/compiled/theme_tech.css b/addons/mass_mailing/static/src/css/compiled/theme_tech.css
deleted file mode 100644
index f003757f2bb..00000000000
--- a/addons/mass_mailing/static/src/css/compiled/theme_tech.css
+++ /dev/null
@@ -1,151 +0,0 @@
-.o_layout.o_tech_theme {
-  background-color: #333;
-}
-.o_layout.o_tech_theme .o_mail_wrapper {
-  background-color: transparent;
-  color: #bdbdbd;
-  border: none;
-}
-.o_layout.o_tech_theme .o_mail_snippet_general .btn.btn-primary {
-  color: white;
-  background-color: #59cdcd;
-}
-.o_layout.o_tech_theme .o_mail_snippet_general .o_mail_full_width_padding {
-  padding-left: 20px;
-  padding-right: 20px;
-}
-.o_layout.o_tech_theme .o_mail_snippet_general a,
-.o_layout.o_tech_theme .o_mail_snippet_general .o_mail_link {
-  font-weight: normal;
-  color: #59cdcd;
-}
-.o_layout.o_tech_theme .o_mail_snippet_general .bg-beta {
-  background-color: #59cdcd;
-}
-.o_layout.o_tech_theme .o_mail_snippet_general .bg-beta .btn.btn-primary {
-  color: white;
-  background-color: #a17e92;
-}
-.o_layout.o_tech_theme .o_mail_snippet_general .text-beta {
-  color: #59cdcd;
-}
-.o_layout.o_tech_theme .o_mail_snippet_general .bg-delta {
-  background-color: #a17e92;
-}
-.o_layout.o_tech_theme .o_mail_snippet_general h1,
-.o_layout.o_tech_theme .o_mail_snippet_general h2,
-.o_layout.o_tech_theme .o_mail_snippet_general h3,
-.o_layout.o_tech_theme .o_mail_snippet_general h4,
-.o_layout.o_tech_theme .o_mail_snippet_general h5,
-.o_layout.o_tech_theme .o_mail_snippet_general h6,
-.o_layout.o_tech_theme .o_mail_snippet_general .h1,
-.o_layout.o_tech_theme .o_mail_snippet_general .h2,
-.o_layout.o_tech_theme .o_mail_snippet_general .h3,
-.o_layout.o_tech_theme .o_mail_snippet_general .h4,
-.o_layout.o_tech_theme .o_mail_snippet_general .h5,
-.o_layout.o_tech_theme .o_mail_snippet_general .h6 {
-  color: #e6e6e6;
-}
-.o_layout.o_tech_theme .o_mail_block_header_social .o_mail_snippet_general,
-.o_layout.o_tech_theme .o_mail_block_header_text_social .o_mail_snippet_general,
-.o_layout.o_tech_theme .o_mail_block_header_logo .o_mail_snippet_general {
-  margin-top: 10px;
-  margin-bottom: 25px;
-  padding-left: 20px;
-  padding-right: 20px;
-}
-.o_layout.o_tech_theme .o_mail_block_header_social .o_mail_snippet_general > table,
-.o_layout.o_tech_theme .o_mail_block_header_text_social .o_mail_snippet_general > table,
-.o_layout.o_tech_theme .o_mail_block_header_logo .o_mail_snippet_general > table {
-  max-width: 560px;
-  border-bottom: 1px solid #666666;
-}
-.o_layout.o_tech_theme .o_mail_block_header_social .o_mail_h_padding.o_mail_v_padding,
-.o_layout.o_tech_theme .o_mail_block_header_text_social .o_mail_h_padding.o_mail_v_padding,
-.o_layout.o_tech_theme .o_mail_block_header_logo .o_mail_h_padding.o_mail_v_padding {
-  padding: 10px 0 5px;
-}
-.o_layout.o_tech_theme .o_mail_block_header_social .o_mail_header_social,
-.o_layout.o_tech_theme .o_mail_block_header_text_social .o_mail_header_social,
-.o_layout.o_tech_theme .o_mail_block_header_logo .o_mail_header_social {
-  margin-right: 0px;
-}
-.o_layout.o_tech_theme .o_mail_block_header_social .o_mail_header_social a,
-.o_layout.o_tech_theme .o_mail_block_header_text_social .o_mail_header_social a,
-.o_layout.o_tech_theme .o_mail_block_header_logo .o_mail_header_social a {
-  color: #999999;
-}
-.o_layout.o_tech_theme .o_mail_block_footer_separator .separator {
-  height: 1px;
-  background-color: #666666;
-}
-.o_layout.o_tech_theme .o_mail_block_event {
-  margin-left: 20px;
-  margin-right: 20px;
-}
-.o_layout.o_tech_theme .o_mail_block_event h1,
-.o_layout.o_tech_theme .o_mail_block_event h2,
-.o_layout.o_tech_theme .o_mail_block_event h3,
-.o_layout.o_tech_theme .o_mail_block_event h4,
-.o_layout.o_tech_theme .o_mail_block_event h5,
-.o_layout.o_tech_theme .o_mail_block_event h6,
-.o_layout.o_tech_theme .o_mail_block_event .h1,
-.o_layout.o_tech_theme .o_mail_block_event .h2,
-.o_layout.o_tech_theme .o_mail_block_event .h3,
-.o_layout.o_tech_theme .o_mail_block_event .h4,
-.o_layout.o_tech_theme .o_mail_block_event .h5,
-.o_layout.o_tech_theme .o_mail_block_event .h6 {
-  color: #333;
-}
-.o_layout.o_tech_theme .o_mail_block_discount2 .o_code {
-  color: #333;
-}
-.o_layout.o_tech_theme .o_mail_block_footer_separator {
-  margin-left: 0;
-  margin-right: 0;
-}
-.o_layout.o_tech_theme .o_mail_block_steps {
-  background-color: transparent;
-}
-.o_layout.o_tech_theme .o_mail_block_steps h1,
-.o_layout.o_tech_theme .o_mail_block_steps h2,
-.o_layout.o_tech_theme .o_mail_block_steps h3,
-.o_layout.o_tech_theme .o_mail_block_steps h4,
-.o_layout.o_tech_theme .o_mail_block_steps h5,
-.o_layout.o_tech_theme .o_mail_block_steps h6,
-.o_layout.o_tech_theme .o_mail_block_steps .h1,
-.o_layout.o_tech_theme .o_mail_block_steps .h2,
-.o_layout.o_tech_theme .o_mail_block_steps .h3,
-.o_layout.o_tech_theme .o_mail_block_steps .h4,
-.o_layout.o_tech_theme .o_mail_block_steps .h5,
-.o_layout.o_tech_theme .o_mail_block_steps .h6 {
-  color: #333;
-}
-.o_layout.o_tech_theme .o_mail_block_steps .o_mail_full_width_padding > tbody > tr {
-  background-color: white;
-  color: #333;
-}
-.o_layout.o_tech_theme .o_mail_block_footer_social .o_mail_snippet_general {
-  background: rgba(0, 0, 0, 0);
-  background: transparent;
-}
-.o_layout.o_tech_theme .o_mail_block_footer_social .o_mail_table_styles {
-  border-top: none;
-}
-.o_layout.o_tech_theme .o_mail_block_footer_social .o_mail_footer_social a {
-  color: #999999;
-}
-.o_layout.o_tech_theme .o_mail_block_footer_social .o_mail_footer_links a {
-  color: #999999;
-}
-.o_layout.o_tech_theme .o_mail_block_footer_social .o_mail_footer_copy {
-  font-weight: bold;
-  font-size: 9px;
-  color: #b3b3b3;
-}
-.o_layout.o_tech_theme .o_mail_block_footer_social.o_mail_footer_social_left .o_mail_footer_description {
-  padding-left: 0;
-}
-.o_layout.o_tech_theme .o_mail_block_footer_social.o_mail_footer_social_left .o_mail_footer_social {
-  padding-right: 0;
-}
diff --git a/addons/mass_mailing/static/src/css/themes/theme_newsletter.less b/addons/mass_mailing/static/src/css/themes/theme_newsletter.less
deleted file mode 100644
index 7962c9bdfc3..00000000000
--- a/addons/mass_mailing/static/src/css/themes/theme_newsletter.less
+++ /dev/null
@@ -1,41 +0,0 @@
-// out: ../compiled/theme_newsletter.css, sourcemap: false, compress: false
-// lessc@1.4.2
-
-
-// ===========   Variables
-
-// 'Default Theme' Palette
-@o_mm_news_color_alpha   : #f5f5f5;
-@o_mm_news_color_beta    : #ffffff;
-@o_mm_news_color_gamma   : #1cc1a9;
-@o_mm_news_color_delta   : #464646;
-@o_mm_news_color_epsilon : darken(@o_mm_news_color_gamma, 5%);
-@o_mm_news_color_zeta    : #906784;
-@o_mm_news_color_eta     : #87a6b5;
-
-
-// ===========   Components
-
-.o_layout.o_newsletter_theme {
-    .o_mail_snippet_general {
-        .btn.btn-primary {
-            color: @o_mm_news_color_beta;
-            background-color: @o_mm_news_color_gamma;
-        }
-        a, .btn.btn-link {
-            color: @o_mm_news_color_epsilon;
-        }
-        .bg-beta {
-            background-color: @o_mm_news_color_zeta;
-            color:  @o_mm_news_color_beta;
-        }
-        .text-beta {
-            color: @o_mm_news_color_zeta;
-        }
-
-        .bg-delta {
-            background-color: @o_mm_news_color_eta;
-        }
-    }
-}
-
diff --git a/addons/mass_mailing/static/src/css/themes/theme_airmail.less b/addons/mass_mailing/static/src/less/themes/theme_airmail.less
index fdb02d0fa00..513f3dc57c2 100644
--- a/addons/mass_mailing/static/src/css/themes/theme_airmail.less
+++ b/addons/mass_mailing/static/src/less/themes/theme_airmail.less
@@ -1,26 +1,53 @@
-// out: ../compiled/theme_airmail.css, sourcemap: false, compress: false
 // lessc@1.4.2
 
+// ============================
+// Mass Mailing "Theme Airmail"
+// ============================
 
-@o_mm_airmail_color_alpha   : #EAECED;
-@o_mm_airmail_color_beta    : white;
-@o_mm_airmail_color_gamma   : #FB3C6B;
-@o_mm_airmail_color_delta   : darken(@o_mm_airmail_color_gamma, 5%);
-@o_mm_airmail_color_epsilon : black;
-@o_mm_airmail_color_zeta    : #a17e92;
+@o_mm_airmail_color_alpha: #EAECED;
+@o_mm_airmail_color_beta: white;
+@o_mm_airmail_color_gamma: #FB3C6B;
+@o_mm_airmail_color_delta: darken(@o_mm_airmail_color_gamma, 5%);
+@o_mm_airmail_color_epsilon: black;
+@o_mm_airmail_color_zeta: #a17e92;
 
+.o_airmail_theme {
+    // ===== Colors =====
+    .bg-beta {
+        background-color: @o_mm_airmail_color_gamma;
 
-.o_layout.o_airmail_theme {
-    background-color: @o_mm_airmail_color_alpha;
+        .btn.btn-primary {
+            color: @o_mm_airmail_color_beta;
+            background-color: @o_mm_airmail_color_zeta;
+        }
 
-    .o_mail_wrapper {
-        background: rgba(0,0,0,0);
-        background: transparent;
-        border: none;
+        h1, h2, h3, h4, h5, h6, .h1, .h2, .h3, .h4, .h5, .h6 {
+            color: @o_mm_airmail_color_beta;
+        }
     }
+    .text-beta {
+        color: @o_mm_airmail_color_gamma;
+    }
+    .bg-delta {
+        background-color: @o_mm_airmail_color_zeta;
+    }
+
+    // ===== Layout =====
+    &.o_layout {
+        background-color: @o_mm_airmail_color_alpha;
 
-    // ===========   Components
+        > .o_mail_wrapper {
+            background: rgba(0, 0, 0, 0);
+            background: transparent;
+            border: none;
 
+            > * {
+                margin-bottom: 16px;
+            }
+        }
+    }
+
+    // ===== Snippets (general) =====
     .o_mail_snippet_general {
         background-color: @o_mm_airmail_color_beta;
         color: @o_mm_airmail_color_epsilon;
@@ -33,55 +60,26 @@
         a, .o_mail_link {
             color: @o_mm_airmail_color_delta;
         }
-
-        .bg-beta {
-            background-color: @o_mm_airmail_color_gamma;
-
-            .btn.btn-primary {
-                color: @o_mm_airmail_color_beta;
-                background-color: @o_mm_airmail_color_zeta;
-            }
-
-            h1, h2, h3, h4, h5, h6, .h1, .h2, .h3, .h4, .h5, .h6 {
-                color: @o_mm_airmail_color_beta;
-            }
-        }
-        .text-beta {
-            color: @o_mm_airmail_color_gamma;
-        }
-
-        .bg-delta {
-            background-color: @o_mm_airmail_color_zeta;
-        }
     }
 
-    // =========== Snippets
+    // ===== Snippets (specific) =====
+    .o_mail_block_header_social, .o_mail_block_header_text_social, .o_mail_block_header_logo {
+        margin-bottom: 0;
 
-    .o_mail_wrapper {
-        > div { // All snippets
-            margin-bottom: 16px;
+        .o_mail_snippet_general {
+            background: rgba(0,0,0,0);
+            background: transparent;
         }
-    }
-
-    .o_mail_wrapper {
-        .o_mail_block_header_social, .o_mail_block_header_text_social, .o_mail_block_header_logo {
-            margin-bottom: 0;
-
-            .o_mail_snippet_general {
-                background: rgba(0,0,0,0);
-                background: transparent;
-            }
 
-            .o_mail_h_padding {
-                padding-left: 0;
-                padding-right: 0;
-            }
+        .o_mail_h_padding {
+            padding-left: 0;
+            padding-right: 0;
+        }
 
-            .o_mail_header_social {
-                margin-right: 0px;
-                a {
-                    color: darken(@o_mm_airmail_color_alpha, 40%);
-                }
+        .o_mail_header_social {
+            margin-right: 0px;
+            a {
+                color: darken(@o_mm_airmail_color_alpha, 40%);
             }
         }
     }
@@ -123,9 +121,6 @@
         }
     }
 
-    .o_mail_block_banner {
-    }
-
     .o_mail_block_two_cols, .o_mail_block_three_cols {
         @tmp-gap: 10px;
 
@@ -208,4 +203,4 @@
             }
         }
     }
-}
\ No newline at end of file
+}
diff --git a/addons/mass_mailing/static/src/css/themes/theme_default.less b/addons/mass_mailing/static/src/less/themes/theme_default.less
index daf6f89521c..80a8e523d48 100644
--- a/addons/mass_mailing/static/src/css/themes/theme_default.less
+++ b/addons/mass_mailing/static/src/less/themes/theme_default.less
@@ -1,24 +1,19 @@
-// out: ../compiled/theme_default.css, sourcemap: false, compress: false
 // lessc@1.4.2
 
-// =======================================
-// ========== Mass Mailing "Theme Default"
-// =======================================
+// ============================
+// Mass Mailing "Theme Default"
+// ============================
 
+// ===== Default Theme palette =====
+@o_mm_def_color_alpha: #f5f5f5;
+@o_mm_def_color_beta: #ffffff;
+@o_mm_def_color_gamma: #706482;
+@o_mm_def_color_delta: #464646;
+@o_mm_def_color_epsilon: darken(@o_mm_def_color_gamma, 5%);
+@o_mm_def_color_zeta: #706482;
+@o_mm_def_color_eta: #87a6b5;
 
-// ===========   Variables
-
-// 'Default Theme' Palette
-@o_mm_def_color_alpha   : #f5f5f5;
-@o_mm_def_color_beta    : #ffffff;
-@o_mm_def_color_gamma   : #706482;
-@o_mm_def_color_delta   : #464646;
-@o_mm_def_color_epsilon : darken(@o_mm_def_color_gamma, 5%);
-@o_mm_def_color_zeta    : #706482;
-@o_mm_def_color_eta     : #87a6b5;
-
-
-// Assign 'Default Theme' Variables
+// ===== Default Theme variables =====
 @o_mm_def_body_width    : 600px;
 @o_mm_def_body_bobile   : 480px;
 @o_mm_def_b_radius      : 2px;
@@ -29,18 +24,34 @@
 @o_mm_def_btn_bg        : @o_mm_def_color_gamma;
 @o_mm_def_btn_text      : @o_mm_def_color_beta;
 
-
-// ===========   Editor
-
+// ===== Editor =====
 #web_editor_inside_iframe {
     #wrapwrap > main #editable_area {
         background-color: transparent;
     }
 }
 
+// ===== Colors =====
+.bg-beta {
+    background-color: @o_mm_def_color_zeta;
+    color:  @o_mm_def_color_beta;
+
+    h1, h2, h3, h4, h5, h6, .h1, .h2, .h3, .h4, .h5, .h6 {
+        color: @o_mm_def_color_beta;
+    }
+}
+.text-beta {
+    color: @o_mm_def_color_zeta;
+}
+.bg-delta {
+    background-color: @o_mm_def_color_eta;
+}
+.bg-gray-lighter {
+    background-color: @o_mm_def_color_alpha;
+}
 
-// ===========   Components
 
+// ===== Layout =====
 .o_layout {
     font-family: @o_mm_def_font;
     color: lighten(@o_mm_def_text_color, 20%);
@@ -48,9 +59,9 @@
     width: 100%;
     min-height: 100%;
     background-color: @o_mm_def_color_alpha;
-    padding-bottom: 20px;
+    padding: 24px;
 
-    .o_mail_wrapper {
+    > .o_mail_wrapper {
         width: 100%;
         max-width: @o_mm_def_body_width;
         margin: auto;
@@ -59,7 +70,7 @@
     }
 }
 
-
+// ===== Snippets (general) =====
 .o_mail_snippet_general {
     width: 100%;
     max-width: @o_mm_def_body_width;
@@ -69,7 +80,6 @@
         color: @o_mm_def_text_color;
     }
 
-
     .btn.btn-primary {
         -webkit-user-select: none;
         color: @o_mm_def_btn_text;
@@ -102,31 +112,9 @@
         height: 2px;
         background-color: @o_mm_def_color_alpha;
     }
-
-    .bg-beta {
-        background-color: @o_mm_def_color_zeta;
-        color:  @o_mm_def_color_beta;
-
-        h1, h2, h3, h4, h5, h6, .h1, .h2, .h3, .h4, .h5, .h6 {
-            color: @o_mm_def_color_beta;
-        }
-    }
-    .text-beta {
-        color: @o_mm_def_color_zeta;
-    }
-
-    .bg-delta {
-        background-color: @o_mm_def_color_eta;
-    }
-
-    .bg-gray-lighter {
-        background-color: @o_mm_def_color_alpha;
-    }
 }
 
-
-// ===========   Snippets
-
+// ===== Snippets (specific) =====
 .o_mail_block_header_social, .o_mail_block_header_text_social, .o_mail_block_header_logo {
     .o_mail_logo_container {
         img {
@@ -238,16 +226,12 @@
     }
 }
 
-// ===========   Typography
-
-
 .o_mail_display_coupon {
     font-size: 50px;
     line-height: 1;
 }
 
-/* ======================== MISC ====================== */
-
+// ===== Misc =====
 .o_mail_h_padding {
     padding-left: 20px;
     padding-right: 20px;
@@ -268,8 +252,7 @@
     border-collapse:separate;
 }
 
-// =========== Mobile
-
+// ===== Mobile =====
 @media screen and (max-width: @o_mm_def_body_bobile) {
     .o_mail_col_mv {
         display: block!important;
diff --git a/addons/mass_mailing/static/src/less/themes/theme_newsletter.less b/addons/mass_mailing/static/src/less/themes/theme_newsletter.less
new file mode 100644
index 00000000000..317116d970c
--- /dev/null
+++ b/addons/mass_mailing/static/src/less/themes/theme_newsletter.less
@@ -0,0 +1,38 @@
+// lessc@1.4.2
+
+// ===============================
+// Mass Mailing "Theme Newsletter"
+// ===============================
+
+@o_mm_news_color_alpha: #f5f5f5;
+@o_mm_news_color_beta: #ffffff;
+@o_mm_news_color_gamma: #1cc1a9;
+@o_mm_news_color_delta: #464646;
+@o_mm_news_color_epsilon: darken(@o_mm_news_color_gamma, 5%);
+@o_mm_news_color_zeta: #906784;
+@o_mm_news_color_eta: #87a6b5;
+
+.o_newsletter_theme {
+    // ===== Colors =====
+    .bg-beta {
+        background-color: @o_mm_news_color_zeta;
+        color:  @o_mm_news_color_beta;
+    }
+    .text-beta {
+        color: @o_mm_news_color_zeta;
+    }
+    .bg-delta {
+        background-color: @o_mm_news_color_eta;
+    }
+
+    // ===== Snippets (general) =====
+    .o_mail_snippet_general {
+        .btn.btn-primary {
+            color: @o_mm_news_color_beta;
+            background-color: @o_mm_news_color_gamma;
+        }
+        a, .btn.btn-link {
+            color: @o_mm_news_color_epsilon;
+        }
+    }
+}
diff --git a/addons/mass_mailing/static/src/css/themes/theme_resto.less b/addons/mass_mailing/static/src/less/themes/theme_resto.less
index 2b46dc2e4b7..591850a4e3b 100644
--- a/addons/mass_mailing/static/src/css/themes/theme_resto.less
+++ b/addons/mass_mailing/static/src/less/themes/theme_resto.less
@@ -1,28 +1,57 @@
-// out: ../compiled/theme_resto.css, sourcemap: false, compress: false
 // lessc@1.4.2
 
-@o_mm_resto_color_alpha   : #f0ede0;
-@o_mm_resto_color_beta    : #ffffff;
-@o_mm_resto_color_gamma   : #E96D1F;
-@o_mm_resto_color_delta   : #712b22;
-@o_mm_resto_color_epsilon : darken(@o_mm_resto_color_gamma, 5%);
-@o_mm_resto_color_zeta    : #795745;
+// ==========================
+// Mass Mailing "Theme Resto"
+// ==========================
+
+@o_mm_resto_color_alpha: #f0ede0;
+@o_mm_resto_color_beta: #ffffff;
+@o_mm_resto_color_gamma: #E96D1F;
+@o_mm_resto_color_delta: #712b22;
+@o_mm_resto_color_epsilon: darken(@o_mm_resto_color_gamma, 5%);
+@o_mm_resto_color_zeta: #795745;
+
+.o_resto_theme {
+    // ===== Editor =====
+    &#web_editor_inside_iframe {
+        background-color: @o_mm_resto_color_alpha;
+    }
 
-#web_editor_inside_iframe.o_resto_theme  {
-    background-color: @o_mm_resto_color_alpha;
-}
+    // ===== Colors =====
+    .bg-beta {
+        background-color: @o_mm_resto_color_zeta;
+        color: @o_mm_resto_color_beta;
 
-.o_layout.o_resto_theme {
-    background-color: @o_mm_resto_color_alpha;
+        h1, h2, h3, h4, h5, h6, .h1, .h2, .h3, .h4, .h5, .h6 {
+            color: @o_mm_resto_color_beta;
+        }
+    }
+    .text-beta {
+        color: @o_mm_resto_color_zeta;
+    }
+    .bg-delta {
+        background-color: @o_mm_resto_color_gamma;
+        color: @o_mm_resto_color_beta;
 
-    .o_mail_wrapper {
-        border: none;
-        background-color:transparent;
+        h1, h2, h3, h4, h5, h6, .h1, .h2, .h3, .h4, .h5, .h6 {
+            color: @o_mm_resto_color_beta;
+        }
+    }
+    .text-delta {
+        color: @o_mm_resto_color_epsilon;
     }
 
+    // ===== Layout =====
+    &.o_layout {
+        background-color: @o_mm_resto_color_alpha;
 
-    // ===========   Components
+        > .o_mail_wrapper {
+            border: none;
+            background-color:transparent;
+        }
+    }
 
+    // ===== Snippets (general) =====
     .o_mail_snippet_general {
         background: rgba(0,0,0,0);
         background: transparent;
@@ -38,32 +67,6 @@
             color: @o_mm_resto_color_epsilon;
         }
 
-        .bg-beta {
-            background-color: @o_mm_resto_color_zeta;
-            color: @o_mm_resto_color_beta;
-
-            h1, h2, h3, h4, h5, h6, .h1, .h2, .h3, .h4, .h5, .h6 {
-                color: @o_mm_resto_color_beta;
-            }
-        }
-
-        .text-beta {
-            color: @o_mm_resto_color_zeta;
-        }
-
-        .bg-delta {
-            background-color: @o_mm_resto_color_gamma;
-            color: @o_mm_resto_color_beta;
-
-            h1, h2, h3, h4, h5, h6, .h1, .h2, .h3, .h4, .h5, .h6 {
-                color: @o_mm_resto_color_beta;
-            }
-        }
-
-        .text-delta {
-            color: @o_mm_resto_color_epsilon;
-        }
-
         .separator {
             background-color: lighten(@o_mm_resto_color_zeta, 20%);
         }
@@ -74,7 +77,7 @@
         font-weight: bold;
     }
 
-    // ===========   Snippets
+    // ===== Snippets (specific) =====
     .o_mail_block_header_social, .o_mail_block_header_text_social, .o_mail_block_header_logo {
         .o_mail_snippet_general {
             border-bottom: 5px solid @o_mm_resto_color_gamma;
@@ -97,6 +100,7 @@
             background: darken(@o_mm_resto_color_beta, 2%);
         }
     }
+
     .o_mail_block_header_social, .o_mail_block_header_text_social, .o_mail_block_header_logo, .o_mail_block_steps, .o_mail_block_event, .o_mail_block_banner {
         margin-left: 20px;
         margin-right: 20px;
diff --git a/addons/mass_mailing/static/src/css/themes/theme_tech.less b/addons/mass_mailing/static/src/less/themes/theme_tech.less
index dfb49eab2f9..7b7a91ae475 100644
--- a/addons/mass_mailing/static/src/css/themes/theme_tech.less
+++ b/addons/mass_mailing/static/src/less/themes/theme_tech.less
@@ -1,66 +1,67 @@
-// out: ../compiled/theme_tech.css, sourcemap: false, compress: false
 // lessc@1.4.2
 
+// =========================
+// Mass Mailing "Theme Tech"
+// =========================
 
-@o_mm_tech_color_alpha   : #333;
-@o_mm_tech_color_beta    : white;
-@o_mm_tech_color_gamma   : #59cdcd;
-@o_mm_tech_color_delta   : #bdbdbd;
-@o_mm_tech_color_epsilon : black;
-@o_mm_tech_color_zeta    : #a17e92;
+@o_mm_tech_color_alpha: #333;
+@o_mm_tech_color_beta: white;
+@o_mm_tech_color_gamma: #59cdcd;
+@o_mm_tech_color_delta: #bdbdbd;
+@o_mm_tech_color_epsilon: black;
+@o_mm_tech_color_zeta: #a17e92;
 
+.o_tech_theme {
+    // ===== Colors =====
+    .bg-beta {
+        background-color: @o_mm_tech_color_gamma;
 
+        .btn.btn-primary {
+            color: @o_mm_tech_color_beta;
+            background-color: @o_mm_tech_color_zeta;
+        }
+    }
+    .text-beta {
+        color: @o_mm_tech_color_gamma;
+    }
+    .bg-delta {
+        background-color: @o_mm_tech_color_zeta;
+    }
 
-.o_layout.o_tech_theme {
-    background-color: @o_mm_tech_color_alpha;
+    // ===== Layout =====
+    &.o_layout {
+        background-color: @o_mm_tech_color_alpha;
 
-    .o_mail_wrapper {
-        background-color: transparent;
-        color: @o_mm_tech_color_delta;
-        border: none;
+        > .o_mail_wrapper {
+            background-color: transparent;
+            color: @o_mm_tech_color_delta;
+            border: none;
+        }
     }
 
-    // ===========   Components
-
+    // ===== Snippets (general) =====
     .o_mail_snippet_general {
-
         .btn.btn-primary {
             color: @o_mm_tech_color_beta;
             background-color: @o_mm_tech_color_gamma;
         }
+
         .o_mail_full_width_padding {
             padding-left: 20px;
             padding-right: 20px;
         }
+
         a, .o_mail_link {
             font-weight: normal;
             color: @o_mm_tech_color_gamma;
         }
 
-        .bg-beta {
-            background-color: @o_mm_tech_color_gamma;
-
-            .btn.btn-primary {
-                color: @o_mm_tech_color_beta;
-                background-color: @o_mm_tech_color_zeta;
-            }
-        }
-        .text-beta {
-            color: @o_mm_tech_color_gamma;
-        }
-
-        .bg-delta {
-            background-color: @o_mm_tech_color_zeta;
-        }
-
-
         h1, h2, h3, h4, h5, h6, .h1, .h2, .h3, .h4, .h5, .h6 {
             color: darken(@o_mm_tech_color_beta, 10%);
         }
     }
 
-    // =========== Snippets
-
+    // ===== Snippets (specific) =====
     .o_mail_block_header_social, .o_mail_block_header_text_social, .o_mail_block_header_logo {
         .o_mail_snippet_general {
             margin-top: 10px;
@@ -126,9 +127,6 @@
         }
     }
 
-    .o_mail_block_footer_tag_line {
-    }
-
     .o_mail_block_footer_social {
         .o_mail_snippet_general {
             background: rgba(0,0,0,0);
@@ -164,4 +162,4 @@
             }
         }
     }
-}
\ No newline at end of file
+}