Lay out the publishing forms in one column on phones.

Below 600px: labels above full-width inputs, 44px touch targets, 16px
text, and the tabs on the top border of the story box.

publish/style.css

@@ -1,6 +1,9 @@
 input {
   font-family: "Noto Sans", "Verdana", sans-serif;
 }
+input[type=checkbox] {
+  accent-color: #006633;
+}
 #main .grid {
   display: grid;
   grid-template-columns: minmax(75px, 125px) auto;
@@ -178,3 +181,148 @@ ul.error-box li {
   position:relative;
   top:0.6em;
 }
+
+/*
+ * Phones: one column, with each label above its input. The inputs, the
+ * editor and the image box take the full width, the controls are at
+ * least 44px high for fingers, and the text is at least 16px, so that
+ * iOS does not zoom in when an input gets the focus.
+ */
+@media (max-width: 600px) {
+  #main .grid {
+    grid-template-columns: minmax(0, 1fr);
+  }
+  #main .grid > * {
+    min-width: 0;
+  }
+  #main .grid > .leftcolumn {
+    display: none;
+  }
+  #main .grid > label {
+    width: auto;
+    margin-top: 14px;
+    padding-right: 0;
+    text-align: left;
+    font-weight: bold;
+  }
+  #main .grid > .rightcolumn {
+    margin-top: 4px;
+    align-self: stretch;
+  }
+  /* The star of a required field goes inside the right end of the input,
+     so that all the inputs have the same width */
+  #main .grid > .rightcolumn:has(.required) {
+    position: relative;
+  }
+  #main .grid .rightcolumn > input:has(+ .required) {
+    padding-right: 30px;
+  }
+  #main .grid .rightcolumn > .required {
+    position: absolute;
+    top: 50%;
+    right: 12px;
+    transform: translateY(-50%);
+  }
+  #main .grid .rightcolumn > input {
+    flex: 1;
+    min-width: 0;
+    width: auto;
+    min-height: 44px;
+    padding: 8px 12px;
+    font-size: 16px;
+  }
+  #main .grid .rightcolumn input#remember,
+  #main .grid #hidden {
+    flex: none;
+    width: 24px;
+    min-height: 24px;
+    height: 24px;
+    margin: 8px 0;
+  }
+  #main .grid > div.note {
+    margin-top: 4px;
+    text-align: left;
+  }
+
+  /* The Text and Image tabs sit in a row on the top border of the story
+     box, as they touch its left border on a wide screen. They start after
+     its round corner. */
+  #main .tabs {
+    flex-direction: row;
+    align-items: flex-end;
+    gap: 6px;
+    padding-top: 18px;
+    padding-left: 10px;
+  }
+  #main .tab {
+    min-height: 44px;
+    box-sizing: border-box;
+    margin: 0;
+    padding: 10px 18px;
+    border-radius: 8px 8px 0 0;
+    text-align: center;
+  }
+  #main .counter {
+    margin: 0 0 6px auto;
+    padding-right: 0;
+  }
+  #main .grid > .textarea {
+    width: 100%;
+    margin-top: 0;
+  }
+  #main .grid .textarea .note {
+    margin-top: 6px;
+    text-align: left;
+  }
+  #main .grid #textparent {
+    min-height: 0;
+  }
+  #uploadparent {
+    height: auto;
+    min-height: 200px;
+  }
+  #main .grid #uploadparent {
+    min-height: 200px;
+  }
+  #uploadparent input[type=file] {
+    box-sizing: border-box;
+    width: 100%;
+    min-height: 44px;
+    font-size: 16px;
+  }
+  #uploadparent input[type=file]::file-selector-button {
+    min-height: 44px;
+    margin-right: 10px;
+    padding: 8px 16px;
+    border: 1px solid #006633;
+    border-radius: 6px;
+    background-color: #ffffff;
+    color: #006633;
+    font: bold 16px "Noto Sans", "Verdana", sans-serif;
+  }
+
+  #main .grid div.g-recaptcha {
+    grid-column: auto;
+    margin: 18px 0 0;
+  }
+
+  #main .submission {
+    display: flex;
+    flex-wrap: wrap;
+    gap: 10px;
+    margin-top: 18px;
+  }
+  #main .submission button {
+    min-height: 44px;
+    margin: 0;
+    padding: 8px 20px;
+    font-size: 16px;
+  }
+
+  ul.error-box {
+    padding: 10px 16px 10px 20px;
+  }
+  ul.error-box li {
+    margin: 4px 0 4px 10px;
+  }
+}