agent.css + docs: migrate icon sizing + popover :not([hidden]) prose (#713 batch 2)

agent.css carried 17 #NNN cookies, mostly attribution refs to the
#394 vibec0re overhaul (mara's full-screen redesign). Most were
not substantive WHY-prose — just "this exists because of #394"
breadcrumbs. The two genuine WHY-explanations move to docs.

Moved to docs/web-ui.md::Per-agent page:
- **Agent icon paragraph**: rewrote with explicit-em-sizing
  rationale (intrinsic <img> dimensions push parent flex container
  open via align-items: stretch height feedback) + the 5em ≈ 6em
  min-height - 0.5em padding × 2 derivation + align-self:
  flex-start sticks-to-top.
- **Overflow button paragraph**: added the :not([hidden]) display
  scoping rationale (UA stylesheet sets display:none on [hidden],
  but author display:flex would override — scope to :not([hidden])
  so the popover stays hidden until JS unhides).

Collapsed in agent.css: 17 cookies scrubbed across the file:
- #360 (full-screen vibec0re overhaul — closed) ×2: section
  header preface + side-panel section header
- #394 (vibec0re header redesign — closed) ×7: header height,
  main column, agent icon, meta-nav, overflow trigger, two
  orphaned-style tombstones
- #411 (popover scoping + icon align-start — closed) ×2: icon
  sticks-to-top + overflow popover scoping
- #568 (OAuth code mask + reveal — closed) ×1: show/hide toggle
- #666 (ask→operator inline-answer slot — closed) ×1: slot
  styling (substance partly in PR #780 docs section)
- #559 (mark all read header row — closed) ×1
- #376 (inbox row layout — closed) ×1: long-message wrap
- #375 (tail pill z-index — closed) ×1: collision fix

agent.css: 17 → 0 refs (100% reduction, fully migrated).

docs/web-ui.md

@@ -807,13 +807,17 @@ Three fixed-position layers frame a full-viewport terminal:
 
 **Fixed-overlay header** (`<header class="agent-header">`): frosted
 glass — `backdrop-filter: blur` lets scrolled terminal rows show
-through. Three flex columns (#394 redesign):
+through. Three flex columns:
 
 - **Agent icon** (`<img class="agent-icon">`): fixed-size square
-  identity anchor (5em, `width: 5em; aspect-ratio: 1;
+  identity anchor — `width: 5em; height: 5em` with explicit pixel
-  align-self: flex-start` — capped so a tall state-row doesn't
+  sizing so the `<img>`'s intrinsic (large) dimensions don't push
-  inflate the icon, #411). Falls back to the dimmed hyperhive mark
+  the parent flex container open via `align-items: stretch`-driven
-  on load error.
+  height feedback. 5em ≈ header content area (header `min-height: 6em`
+  minus `2 × 0.5em` padding). `align-self: flex-start` keeps the
+  icon stuck to the top so a state-row line-wrap doesn't drag it
+  down with it. Falls back to the dimmed hyperhive mark on load
+  error.
 - **Main column** (`.agent-header-main`): two rows.
   - Row 1 (`.agent-header-title-row`): title (`<h2 id="title">`) +
     meta-nav (`<nav id="meta-links">`). Meta-nav renders
@@ -861,8 +865,11 @@ through. Three flex columns (#394 redesign):
     (POST confirm → `POST /api/logout`; SIGINTs any in-flight turn,
     wipes OAuth credential files, flips the agent to `needs_login`
     — session history preserved). All destructive actions require
-    one extra click to acknowledge (#394 — rare ops shouldn't live
+    one extra click to acknowledge — rare ops shouldn't live in the
-    in the primary state strip).
+    primary state strip. The popover's display rules are scoped to
+    `:not([hidden])` so the `[hidden]` HTML attribute's UA `display:
+    none` isn't overridden by the author CSS's `display: flex` —
+    the popover stays hidden until JS removes the attribute.
 
 `/api/state` is fetched once on cold load (+ while
 `status === 'needs_login_in_progress'`); all other updates arrive via

frontend/packages/agent/src/agent.css

@@ -3,18 +3,16 @@
 @import "@hive/shared/base.css";
 @import "@hive/shared/terminal.css";
 
-/* ─── full-screen vibec0re overhaul (issue #360) ──────────────────
+/* ─── full-screen layout overrides ─────────────────────────────────
-   Layout shape: fixed-position frosted-glass header at top, fixed-
+   The agent page mounts a full-viewport terminal under a fixed
-   position composer at bottom, full-viewport terminal in between.
+   frosted-glass header + composer pair. See docs/web-ui.md::Per-agent
-   The terminal scrolls — its text passes BENEATH the floating
+   page for the layer / pill / side-panel structure; rules below
-   header/composer with backdrop-filter blur for the frosted look.
+   override the in-page defaults from @hive/shared. */
-   Inbox + loose-ends move into the side-panel flyout; header pills
-   surface their counts as the only chrome they get. */
 
 :root {
-  /* Bumped to 6em (#394) so the agent icon can be a full-height
+  /* 6em min-height accommodates the full-height agent icon (5em +
-     square identity anchor without crowding the two-row main column
+     padding) alongside the two-row main column (title + nav-links
-     (title + nav-links on top, state strip below). */
+     on top, state strip below). */
   --agent-header-h: 6em;
   --agent-composer-h: 3.6em;
   --agent-frost-bg: rgba(30, 30, 46, 0.72);
@@ -86,7 +84,7 @@ body.agent-shell {
   box-shadow: 0 6px 18px rgba(0, 0, 0, 0.35);
 }
 
-/* Main column: title row on top, state strip below (#394). Centred
+/* Main column: title row on top, state strip below. Centred
    vertically against the full-height icon on the left. */
 .agent-header-main {
   display: flex;
@@ -140,12 +138,10 @@ h2, h3 {
   text-shadow: 0 0 8px rgba(203, 166, 247, 0.4);
 }
 .agent-icon {
-  /* Square identity anchor (#394 — mara's spec). Explicit em sizing
+  /* Square identity anchor — explicit 5em sizing + align-self.
-     so the <img>'s intrinsic (large) dimensions don't push the
+     See docs/web-ui.md::Per-agent page (Agent icon) for the
-     parent flex container open via `align-items: stretch`-driven
+     intrinsic-dim-pushes-parent-flex-open + sticks-to-top
-     height feedback. Width = header content area (header min-h 6em
+     rationale. */
-     - 2 × 0.5em padding ≈ 5em). Sticks to the top so a state-row
-     wrap doesn't drag the icon down with it. (#411) */
   width: 5em;
   height: 5em;
   flex-shrink: 0;
@@ -156,9 +152,9 @@ h2, h3 {
 }
 
 /* Meta-nav links (stats / screen / forge / dashboard / extras) —
-   no underline (#394 mara's spec); hover lights with cyan glow +
+   no underline; hover lights with cyan glow + subtle background
-   subtle background tint. Reads as a row of soft tabs rather than
+   tint. Reads as a row of soft tabs rather than default-styled
-   default-styled inline anchors. */
+   inline anchors. */
 .agent-nav-link {
   color: var(--cyan);
   text-decoration: none;
@@ -176,7 +172,7 @@ h2, h3 {
 }
 
 /* Overflow menu trigger — `⋯` round button on the right of the
-   pills row. Quiet by default, lights on hover / open (#394). */
+   pills row. Quiet by default, lights on hover / open. */
 .overflow-btn {
   background: transparent;
   border: 1px solid var(--purple-dim);
@@ -200,13 +196,11 @@ h2, h3 {
   box-shadow: 0 0 10px -2px var(--purple);
 }
 
-/* Overflow popover — rebuild + new-session (and the dashboard
+/* Overflow popover — rebuild + new-session + logout (and the
-   back-link, prepended in app.js setHeader). Positioned in JS so
+   dashboard back-link, prepended in app.js setHeader). Positioned
-   the menu's top-right corner anchors under the trigger button.
+   in JS so the menu's top-right corner anchors under the trigger
-   `:not([hidden])` scoping (#411): the `[hidden]` HTML attribute
+   button. See docs/web-ui.md::Per-agent page (Overflow button)
-   sets `display: none` via the UA stylesheet, but author CSS's
+   for the `:not([hidden])` scoping rationale. */
-   `display: flex` would override that. Scope display rules so
-   they apply only when the menu is unhidden. */
 .overflow-menu:not([hidden]) {
   display: flex;
   flex-direction: column;
@@ -395,14 +389,12 @@ a:hover { color: var(--fg); text-shadow: 0 0 12px rgba(137, 220, 235, 0.9); }
 }
 .btn-login { color: var(--amber); border-color: var(--amber); }
 .btn-cancel { color: var(--red); border-color: var(--red); font-size: 0.85em; padding: 0.15em 0.6em; }
-/* `.btn-rebuild` was the per-agent header chip — moved into the
+/* Orphaned rules — left here as a tombstone so a search for the
-   overflow menu in #394 (`.overflow-item-rebuild` covers it now).
+   class name finds them. Live consumers gone:
-   The dashboard has its own `.btn-rebuild` rule for the per-row
+   - `.btn-rebuild` was a per-agent header chip (covered now by
-   R3BU1LD form on the SW4RM tab; this one was specific to the
+     `.overflow-item-rebuild` in the overflow menu).
-   per-agent header.
+   - `.btn-send` was a green send-button variant — the dashboard's
-   `.btn-send` was a green send-button variant — orphaned since
+     compose form that used it is retired. */
-   the dashboard's compose form was retired; no live consumer left
-   in either the agent or dashboard tree. */
 .sendform { display: flex; gap: 0.6em; margin-top: 0.5em; }
 .sendform input {
   font-family: inherit; font-size: 1em;
@@ -424,10 +416,10 @@ a:hover { color: var(--fg); text-shadow: 0 0 12px rgba(137, 220, 235, 0.9); }
 }
 .loginform input:focus { outline: 1px solid var(--purple); }
 
-/* #568: show / hide toggle for the masked OAuth-code input. Quiet
+/* Show / hide toggle for the masked OAuth-code input. Quiet by
-   by default (muted border + transparent bg), lights amber on
+   default (muted border + transparent bg), lights amber on hover
-   hover / when pressed (aria-pressed="true") so the operator
+   / when pressed (`aria-pressed="true"`) so the operator sees at
-   sees at a glance whether the code is currently visible. */
+   a glance whether the code is currently visible. */
 .loginform-reveal {
   font-family: inherit;
   font-size: 1em;
@@ -489,7 +481,7 @@ pre.diff {
 /* Inbox / loose-ends rows: header (from / sep / ts) on one line,
    body on its own line below — gives the body the full panel width
    instead of squeezing it into a fourth grid column that wrapped
-   long messages over many narrow lines (issue #376). */
+   long messages over many narrow lines. */
 .agent-inbox li {
   padding: 0.4em 0;
   display: block;
@@ -552,15 +544,16 @@ pre.diff {
 .agent-inbox .answer-form button:disabled { opacity: 0.5; cursor: default; }
 .agent-inbox .answer-status { color: var(--muted); align-self: center; }
 
-/* #666: inline answer slot mounted under each `ask → operator` row
+/* Inline answer slot mounted under each `ask → operator` row in
-   in the live terminal stream. Mirrors the side-panel `.answer-form`
+   the live terminal stream. Mirrors the side-panel `.answer-form`
    look-and-feel — same textarea, same send button — so the operator
-   doesn't have to context-switch between "answering in the panel" and
+   doesn't have to context-switch between "answering in the panel"
-   "answering inline". Empty slot collapses to nothing (no margin) so
+   and "answering inline". Empty slot collapses to nothing (no
-   pre-bind rows stay tidy; populated slot gets a thin top divider to
+   margin) so pre-bind rows stay tidy; populated slot gets a thin
-   separate the question body from the form. Resolved tag (the
+   top divider to separate the question body from the form. A
-   struck-through `[answered ✓]`) replaces the form once the
+   `[resolved]` tag (neutral, covers answered / cancelled /
-   question's been answered. */
+   TTL-expired uniformly) replaces the form once the question
+   leaves the pending list. */
 .live .ask-answer-inline-slot:empty { display: none; }
 .live .ask-answer-inline-slot {
   margin-top: 0.5em;
@@ -613,10 +606,10 @@ pre.diff {
   text-decoration-color: var(--muted);
 }
 
-/* #559: "mark all read" header row sits above the recent-messages
+/* "mark all read" header row sits above the recent-messages list
-   list in the inbox side-panel flyout. Same look as the answer-form
+   in the inbox side-panel flyout. Same look as the answer-form
-   button (mauve hover, bg-elev background) so they read as part of
+   button (mauve hover, bg-elev background) so they read as part
-   the same affordance family. */
+   of the same affordance family. */
 .agent-inbox .inbox-mark-all-row {
   display: flex;
   gap: 0.6em;
@@ -697,8 +690,9 @@ pre.diff {
   text-shadow: 0 0 6px rgba(243, 139, 168, 0.55); }
 .status-badge.status-needs-login  { color: var(--amber);  border-color: var(--amber); }
 .status-badge.status-offline      { color: var(--muted);  border-color: var(--muted); }
-/* Orphaned in #394 — `.btn-dashlink` chip beside the title moved
+/* Orphaned tombstone — `.btn-dashlink` chip that lived beside the
-   into the overflow menu (`.overflow-item-dashboard` covers it). */
+   title was moved into the overflow menu (`.overflow-item-dashboard`
+   covers it now). */
 .btn-cancel-turn {
   font-family: inherit;
   font-size: 0.8em;
@@ -716,8 +710,8 @@ pre.diff {
   background: rgba(243, 139, 168, 0.1);
   box-shadow: 0 0 10px -2px currentColor;
 }
-/* Orphaned in #394 — `.btn-new-session` round-pill moved into the
+/* Orphaned tombstone — `.btn-new-session` round-pill moved into
-   overflow menu (`.overflow-item-new-session` covers it; the
+   the overflow menu (`.overflow-item-new-session` covers it; the
    `:disabled` opacity treatment lives on the shared
    `.overflow-item:disabled` rule). */
 .state-badge {
@@ -793,7 +787,10 @@ pre.diff {
 /* Tail pill (↓ N new): nudged up so it floats clear of the composer
    rather than colliding with the frosted bar. z-index bumped above
    the composer (z-30) so the pill sits on the top layer instead of
-   being clipped by the floating chrome (issue #375). */
+   being clipped by the floating chrome. (Pill is anchored in
+   `.agent-main` rather than `.terminal-wrap` — see
+   docs/web-ui.md::Per-agent page Terminal-wrap paragraph for the
+   backdrop-filter stacking-context rationale.) */
 .agent-main .tail-pill {
   bottom: calc(var(--agent-composer-h) + 0.6em);
   z-index: 35;
@@ -843,10 +840,9 @@ pre.diff {
 /* Row + pill + details styling moved to hive-fr0nt::TERMINAL_CSS. */
 
 /* ─── side panel (singleton drawer) ────────────────────────────────
-   Inbox + loose-ends details open here instead of expanding inline
+   Inbox + loose-ends details open here instead of expanding inline.
-   (issue #360). Copy of the dashboard's side-panel pattern —
+   Copy of the dashboard's side-panel pattern — candidate for
-   candidate for extraction into @hive/shared once both surfaces
+   extraction into @hive/shared once both surfaces stabilize. */
-   stabilize. */
 .side-panel {
   position: fixed;
   inset: 0;