mobile : center text button. homogenize close / open nav btns

assets/css/src/article.css

@@ -15,7 +15,8 @@ article #main-content {
 article #main-content #chapo::after {
   content: "";
   display: block;
-  margin: calc(2 * var(--unit--vertical)) 0;
+  margin-top: calc(2 * var(--unit--vertical));
+  margin-bottom: calc(4 * var(--unit--vertical));
 
   width: 100%;
   height: 1px;

assets/css/src/footer.css

@@ -5,12 +5,7 @@
 
   border-bottom: 0;
 }
-.open-nav-wrapper {
-  border-top: 1px solid #eee;
-  border-right: 1px solid #eee;
-  background-color: #000;
-  padding: 3px var(--unit--horizontal) 6px var(--unit--horizontal);
-}
+
 [data-template="home"] #main-footer {
   position: fixed;
   left: 0;
@@ -25,6 +20,22 @@
   transform: translateY(-1px);
 }
 
+@media screen and (max-width: 640px) {
+  .open-nav {
+    box-sizing: border-box;
+    bottom: 0;
+    display: flex;
+    justify-content: center;
+    width: 100%;
+    outline: none;
+    border-top: 1px solid #fff;
+    font-size: var(--font-size-m);
+    background-color: #000;
+    padding: calc(var(--unit--vertical) / 2) var(--unit--horizontal);
+    margin-bottom: env(safe-area-inset-bottom);
+  }
+}
+
 @media screen and (min-width: 640px) {
   #main-footer li {
     display: block !important;

assets/css/src/generic.css

@@ -107,7 +107,8 @@ body {
 
 /* ================= BUTTONS ================= */
 .toggle-btn--left::after,
-button.plus::after {
+button.plus::after,
+button.less::after {
   margin-left: var(--unit--horizontal);
 }
 
@@ -115,7 +116,8 @@ button.plus::after {
 button.plus::after {
   content: "+";
 }
-.toggle-btn--left.open::after {
+.toggle-btn--left.open::after,
+button.less::after {
   content: "-";
 }
 .toggle-btn--right::before {

assets/css/src/nav.css

@@ -1,7 +1,3 @@
-button.open-nav {
-  display: inline-block;
-}
-
 #nav-overlay {
   position: fixed;
   inset: 0;
@@ -108,6 +104,9 @@ button.search__icon {
   padding: var(--unit--vertical) var(--unit--horizontal);
 }
 
+footer {
+  width: 100%;
+}
 .panel-close {
   position: fixed;
   box-sizing: border-box;