feat(web/panettone): Add initial styles

Take an initial crack at styling most of the Panettone application,
taking inspiration from the styles from todo.tvl.fyi and tvl.fyi itself.
This uses the LASS CSS library, after a brief attempt at using css-lite
which I ended up not going with because I don't like the library's
design very much, and also it's not compatible with sbcl's (safety
3) (some macroexpansions SETQ undeclared variables).

Change-Id: I054402e4c68ae1e99884d5164e6e2fc39d2779ff
Reviewed-on: https://cl.tvl.fyi/c/depot/+/1350
Tested-by: BuildkiteCI
Reviewed-by: eta <eta@theta.eu.org>

web/panettone/src/css.lisp

@@ -0,0 +1,120 @@
+(in-package :panettone.css)
+(declaim (optimize (safety 3)))
+
+(defparameter color/black
+  "rgb(24, 24, 24)")
+
+(defparameter color/gray
+  "#8D8D8D")
+
+(defparameter color/primary
+  "rgb(106, 154, 255)")
+
+(defparameter color/primary-light
+  "rgb(150, 166, 200)")
+
+(defparameter color/success
+  "rgb(168, 249, 166)")
+
+(defparameter color/success-2
+  "rgb(168, 249, 166)")
+
+(defun button (selector)
+  `((,selector
+     :background-color ,color/success
+     :padding "0.5rem"
+     :text-decoration "none"
+     :transition "box-shadow" "0.15s" "ease-in-out")
+
+    ((:and ,selector :hover)
+     :box-shadow "0.25rem" "0.25rem" "0" "0" "rgba(0,0,0,0.08)")
+
+    ((:and ,selector (:or :active :focus))
+     :box-shadow "0.1rem" "0.1rem" "0" "0" "rgba(0,0,0,0.05)"
+     :outline "none"
+     :border "none"
+     :background-color ,color/success-2)))
+
+(defparameter issue-list-styles
+  `((.issue-list
+     :list-style-type "none"
+     :padding-left 0
+
+     (.issue-subject
+      :font-weight "bold")
+
+     (li
+      :padding-bottom "1rem")
+
+     ((li + li)
+      :border-top "1px" "solid" ,color/gray)
+
+     (a
+      :text-decoration "none"
+      :display "block")
+
+     ((:and a :hover)
+      :outline "none"
+
+      (.issue-subject
+       :color ,color/primary)))))
+
+(defparameter form-styles
+  `(((:or (:and input (:or (:= type "text")
+                           (:= type "password")))
+          textarea)
+     :width "100%"
+     :padding "0.5rem"
+     :outline "none"
+     :border-top "none"
+     :border-left "none"
+     :border-right "none"
+     :border-bottom "1px" "solid" ,color/gray
+     :margin-bottom "1rem")
+
+    (textarea
+     :resize "vertical")
+
+    ((:and input (:= type "submit"))
+     :-webkit-appearance "none"
+     :border "none"
+     :cursor "pointer")
+
+    ,@(button '(:and input (:= type "submit")))))
+
+(defparameter styles
+  `(,@form-styles
+    ,@issue-list-styles
+
+    (body
+     :font-family "sans-serif"
+     :color ,color/black)
+
+    (a :color "inherit")
+
+    (.content
+     :width "800px"
+     :margin "0 auto")
+
+    (header
+     :display "flex"
+     :align-items "center"
+     :border-bottom "1px" "solid" ,color/black
+     :margin-bottom "1rem"
+
+     (h1
+      :padding 0
+      :flex 1)
+
+     (.issue-number
+      :color ,color/gray
+      :font-size "1.5rem"))
+
+    ,@(button '.new-issue)
+
+    (.login-form
+     :width "300px"
+     :margin "0 auto")
+
+    (.created-by-at
+     :color ,color/gray)))