webmail/app/boot-skeleton.css

/*
 * Page skeletons (components/boot-skeleton).
 *
 * The server draws every variant of a skeleton; these variants show the one
 * that matches the attributes the boot script set on <html> before the first
 * paint (lib/boot-skeleton/boot-script.ts). Part of the first stylesheet, so
 * nothing here arrives late.
 */

/* Mountain View shell. Its geometry only applies on desktop, so pair it with
   lg: in markup (lg:mv:hidden), except the phone bottom bar, which follows
   the layout at every width. */
@custom-variant mv (&:where([data-interface-layout="mountain-view"] *));

/* Mail layout (effectiveMailLayout: Mountain View and simple mode are focus). */
@custom-variant boot-split (&:where([data-boot-mail-layout="split"] *));
@custom-variant boot-horizontal (&:where([data-boot-mail-layout="horizontal"] *));
@custom-variant boot-focus (&:where([data-boot-mail-layout="focus"] *));

/* A message, thread, contact, settings page or admin page is open. */
@custom-variant boot-open (&:where([data-boot-pane] *));
@custom-variant boot-thread (&:where([data-boot-pane="thread"] *));

/* The Pro interface takes this page over on a desktop. */
@custom-variant boot-pro (&:where([data-boot-pro="on"] *));

/* Nothing stored that checkAuth could restore: draw the login card. */
@custom-variant boot-out (&:where([data-boot-auth="out"] *));

/* Calendar view. */
@custom-variant boot-cal-month (&:where([data-boot-calendar-view="month"] *));
@custom-variant boot-cal-week (&:where([data-boot-calendar-view="week"] *));
@custom-variant boot-cal-day (&:where([data-boot-calendar-view="day"] *));
@custom-variant boot-cal-agenda (&:where([data-boot-calendar-view="agenda"] *));
@custom-variant boot-cal-tasks (&:where([data-boot-calendar-view="tasks"] *));
@custom-variant boot-cal-collapsed (&:where([data-boot-collapsed~="calendar"] *));

/* Files. */
@custom-variant boot-files-grid (&:where([data-boot-files-view="grid"] *));
@custom-variant boot-files-details (&:where([data-boot-files-details="on"] *));

/* What the rail showed last time (bulwark-boot-hints). Without hints every
   app is drawn: the rail of a server with all of them. */
@custom-variant boot-no-calendar (&:where([data-boot-rail]:not([data-boot-rail~="calendar"]) *));
@custom-variant boot-no-contacts (&:where([data-boot-rail]:not([data-boot-rail~="contacts"]) *));
@custom-variant boot-no-files (&:where([data-boot-rail]:not([data-boot-rail~="files"]) *));
@custom-variant boot-rail-add-app (&:where([data-boot-rail~="add-app"] *));
@custom-variant boot-rail-admin (&:where([data-boot-rail~="admin"] *));
@custom-variant boot-rail-a11y (&:where([data-boot-rail~="a11y"] *));
@custom-variant boot-rail-quota (&:where([data-boot-rail~="quota"] *));

/* A placeholder shape. A slow opacity pulse rather than a moving shimmer:
   opacity runs on the compositor, so the skeleton costs the main thread
   nothing while the app's JS is still starting up. */
.sk-shape {
  background-color: var(--color-muted);
  animation: sk-pulse 2s cubic-bezier(0.4, 0, 0.6, 1) infinite;
}

@keyframes sk-pulse {
  50% {
    opacity: 0.55;
  }
}

/* Reduced motion: no pulse at all (the global rule only shortens it). */
@media (prefers-reduced-motion: reduce) {
  :root:not([data-motion="full"]) .sk-shape {
    animation: none;
  }
}
:root[data-motion="reduce"] .sk-shape {
  animation: none;
}

/* More contrast: shapes that stand out from the panels they sit on. */
@media (prefers-contrast: more) {
  :root:not([data-contrast="normal"]) .sk-shape {
    background-color: color-mix(in oklab, var(--color-foreground) 28%, transparent);
  }
}
:root[data-contrast="more"] .sk-shape {
  background-color: color-mix(in oklab, var(--color-foreground) 28%, transparent);
}

/* Forced colours drop backgrounds; keep the shapes as system grey. */
@media (forced-colors: active) {
  .sk-shape {
    forced-color-adjust: none;
    background-color: GrayText;
    animation: none;
  }
}

/* mail */

/* List density (the density setting, data-boot-density): extra-compact rows
   (boot-density-xc, the same variant contacts uses: drop one copy on merging)
   have no avatar, compact and extra-compact ones no preview. */
@custom-variant boot-density-xc (&:where([data-boot-density="extra-compact"] *));
@custom-variant boot-dense (&:where([data-boot-density="compact"] *, [data-boot-density="extra-compact"] *));
/* Message previews turned off (showPreview). */
@custom-variant boot-no-preview (&:where([data-boot-preview="off"] *));
/* The default interface layout, the opposite of mv: (both can't be told apart by order). */
@custom-variant boot-std (&:where(:root:not([data-interface-layout="mountain-view"]) *));
/* Mountain View's side panel shows only with calendar or contacts. */
@custom-variant boot-no-mv-side (&:where([data-boot-rail]:not([data-boot-rail~="calendar"]):not([data-boot-rail~="contacts"]) *));

/* Message list rows (MailListRowsSkeleton), in short classes because a
   skeleton draws dozens of them. Geometry as ThreadListItem's: a 1px rule,
   the cell's density padding and gap, its minimum height on stacked rows.
   In the components layer, so utilities on the same element still win. */
@layer components {
  .sk-mrow {
    border-bottom: 1px solid var(--color-border);
    background-color: var(--color-background);
  }
  .sk-mcell {
    display: flex;
    align-items: flex-start;
    gap: var(--density-item-gap);
    padding: var(--density-item-py) 0.75rem;
  }
  .sk-mcell-min {
    min-height: var(--list-item-height);
  }
  /* The avatar's column: centred on the row. */
  .sk-mav {
    display: flex;
    flex-shrink: 0;
    align-self: stretch;
    align-items: center;
  }
  /* A line of text as tall as the real one (font size and leading from its
     classes), with its bar centred on it. */
  .sk-ml {
    position: relative;
    display: block;
    height: 1lh;
  }
  .sk-ml > .sk-shape {
    position: absolute;
    inset-block: 0;
    inset-inline-start: 0;
    height: 0.75rem;
    margin-block: auto;
    border-radius: 0.25rem;
  }
}

/* Panels drawn in the shapes' own colour (the sidebar in dark themes, the
   Mountain View phone header): lift the shapes off them. Below the contrast
   rules' specificity, and not in forced colours. */
@media not (forced-colors: active) {
  :where(.dark) .sk-lift-dark .sk-shape,
  :where([data-interface-layout="mountain-view"]) .sk-lift-mv .sk-shape,
  .sk-lift .sk-shape {
    background-color: color-mix(in oklab, var(--color-foreground) 10%, transparent);
  }
}