/* ============================================================
   Explorer — primary deliverable
   3-column app shell with mode-as-hero filter chips
   ============================================================ */

.ex-shell {
  display: grid;
  grid-template-rows: 64px auto 1fr auto;
  height: 100vh;
  min-height: 760px;
  min-width: 1320px;
  background: var(--surface-canvas);
}
body { overflow-x: auto; }

/* ─── TOP BAR ────────────────────────────────────────────────── */
.ex-topbar {
  display: flex;
  align-items: center;
  gap: 24px;
  padding: 0 28px;
  background: var(--surface-base);
  border-bottom: 1px solid var(--border-divider);
}
.ex-brand {
  display: flex;
  align-items: center;
  gap: 14px;
  min-width: 0;
}
.ex-logo {
  width: 36px;
  height: 36px;
  border-radius: var(--radius-md);
  background: linear-gradient(135deg, var(--ut-teal-500) 0%, var(--ut-blue-500) 55%, var(--ut-yellow-500) 100%);
  display: grid;
  place-items: center;
  color: white;
  font: 800 16px/1 var(--font-body);
  letter-spacing: -0.02em;
}
.ex-brand-title {
  font: 700 16px/1.2 var(--font-body);
  color: var(--fg-heading-strong);
  letter-spacing: -0.005em;
}
.ex-brand-sub {
  font: 400 12px/1.3 var(--font-body);
  color: var(--fg-body-light);
  margin-top: 1px;
}

.ex-topbar-spacer { flex: 1; }

.ex-search {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 0 12px;
  height: 36px;
  background: var(--surface-canvas);
  border: 1px solid var(--border-input);
  border-radius: var(--radius-md);
  min-width: 320px;
  color: var(--icon-default);
  transition: border-color var(--duration-fast) var(--ease-out);
}
.ex-search:focus-within {
  border-color: var(--border-focus);
  background: var(--surface-base);
  box-shadow: 0 0 0 3px rgba(var(--rgb-blue-500), 0.12);
}
.ex-search svg { flex: 0 0 auto; }
.ex-search input {
  border: 0;
  outline: 0;
  background: transparent;
  flex: 1;
  font: 400 14px/1 var(--font-body);
  color: var(--fg-body-strong);
}
.ex-search input::placeholder { color: var(--fg-body-light); }
.ex-search-clear {
  border: 0;
  background: transparent;
  color: var(--fg-link);
  font: 600 12px/1 var(--font-body);
  cursor: pointer;
  padding: 4px 6px;
  border-radius: var(--radius-xs);
}
.ex-search-clear:hover { background: var(--hover-bg); }

.ex-count {
  font: 600 12px/1 var(--font-body);
  color: var(--fg-body-light);
  white-space: nowrap;
}
.ex-count strong {
  font-weight: 700;
  color: var(--fg-heading-strong);
}

/* ─── MODE HERO ──────────────────────────────────────────────── */
.ex-modebar {
  display: grid;
  grid-template-columns: 280px repeat(3, 1fr);
  gap: 14px;
  padding: 20px 28px;
  background: var(--surface-base);
  border-bottom: 1px solid var(--border-divider);
  align-items: stretch;
}
.ex-modebar-lede {
  display: flex;
  flex-direction: column;
  justify-content: center;
  max-width: 260px;
  padding-right: 12px;
}
.ex-modebar-eyebrow {
  font: 700 10px/1 var(--font-body);
  letter-spacing: 0.12em;
  color: var(--fg-body-light);
  text-transform: uppercase;
  margin-bottom: 6px;
}
.ex-modebar-headline {
  font: 700 18px/1.25 var(--font-body);
  color: var(--fg-heading-strong);
  letter-spacing: -0.01em;
  margin: 0;
}
.ex-mode-chip {
  display: grid;
  grid-template-columns: auto 1fr auto;
  align-items: center;
  gap: 14px;
  padding: 14px 16px;
  border-radius: var(--radius-lg);
  background: var(--surface-base);
  border: 1.5px solid var(--border-divider);
  cursor: pointer;
  text-align: left;
  font: inherit;
  color: inherit;
  transition: all var(--duration-fast) var(--ease-out);
  min-width: 0;
}
.ex-mode-chip:hover {
  border-color: var(--mode-line);
  transform: translateY(-1px);
  box-shadow: var(--shadow-sm);
}
.ex-mode-chip.is-on {
  background: var(--mode-bg);
  border-color: var(--mode-line);
}
.ex-mode-chip.is-off {
  opacity: 0.55;
}
.ex-mode-chip .ex-mode-count {
  font: 800 36px/1 var(--font-body);
  color: var(--mode-fg);
  letter-spacing: -0.03em;
  font-variant-numeric: tabular-nums;
  min-width: 48px;
}
.ex-mode-chip .ex-mode-meta { min-width: 0; }
.ex-mode-chip .ex-mode-label {
  font: 700 15px/1.2 var(--font-body);
  color: var(--mode-fg);
  letter-spacing: -0.005em;
  margin-bottom: 2px;
  display: flex;
  align-items: center;
  gap: 8px;
}
.ex-mode-chip .ex-mode-dot {
  width: 8px; height: 8px; border-radius: 50%;
  background: var(--mode-mark);
  flex: 0 0 auto;
}
.ex-mode-chip .ex-mode-short {
  font: 400 12px/1.4 var(--font-body);
  color: var(--mode-fg);
  opacity: 0.78;
  display: -webkit-box;
  -webkit-line-clamp: 3;
  -webkit-box-orient: vertical;
  overflow: hidden;
}
.ex-mode-chip .ex-mode-check {
  width: 22px; height: 22px;
  border-radius: var(--radius-xs);
  border: 1.5px solid var(--mode-line);
  background: var(--surface-base);
  display: grid;
  place-items: center;
  flex: 0 0 auto;
}
.ex-mode-chip.is-on .ex-mode-check {
  background: var(--mode-mark);
  border-color: var(--mode-mark);
  color: white;
}
.ex-mode-chip.is-off .ex-mode-check {
  border-color: var(--border-divider);
}

/* ─── BODY GRID ──────────────────────────────────────────────── */
.ex-body {
  display: grid;
  grid-template-columns: 240px minmax(0, 1fr) 520px;
  /* Pin the row to the container so each column inherits a bounded height
     instead of stretching to whichever column's content is tallest. Without
     this, the implicit `auto` row sizes to max-content and the columns'
     `overflow-y: auto` never triggers. */
  grid-template-rows: minmax(0, 1fr);
  overflow: hidden;
  min-height: 0;
}

/* Pair with the row pin: grid items default to min-height: auto, so we also
   need to let them shrink below their content size. */
.ex-sidebar,
.ex-list,
.ex-detail { min-height: 0; }

/* ─── SIDEBAR ────────────────────────────────────────────────── */
.ex-sidebar {
  border-right: 1px solid var(--border-divider);
  background: var(--surface-base);
  padding: 22px 16px;
  overflow-y: auto;
  display: flex;
  flex-direction: column;
  gap: 24px;
}
.ex-side-section { display: flex; flex-direction: column; gap: 4px; }
.ex-side-title {
  font: 700 10px/1 var(--font-body);
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--fg-body-light);
  padding: 0 8px;
  margin-bottom: 8px;
}
.ex-phase-row {
  display: grid;
  grid-template-columns: 22px 1fr auto;
  align-items: center;
  gap: 10px;
  padding: 8px 10px;
  border-radius: var(--radius-sm);
  cursor: pointer;
  font: 600 13px/1.3 var(--font-body);
  color: var(--fg-body-strong);
  transition: background var(--duration-fast) var(--ease-out);
}
.ex-phase-row:hover { background: var(--hover-bg); }
.ex-phase-row.is-on { background: var(--selected-bg); }
.ex-phase-row input {
  appearance: none;
  width: 16px; height: 16px;
  border: 1.5px solid var(--border-input);
  border-radius: 4px;
  margin: 0;
  cursor: pointer;
  position: relative;
  background: var(--surface-base);
}
.ex-phase-row.is-on input {
  background: var(--btn-primary-bg);
  border-color: var(--btn-primary-bg);
}
.ex-phase-row.is-on input::after {
  content: '';
  position: absolute;
  inset: 0;
  background: url("data:image/svg+xml;utf8,<svg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 16 16' fill='none' stroke='white' stroke-width='2.5' stroke-linecap='round' stroke-linejoin='round'><polyline points='3,8.5 6.5,12 13,4.5'/></svg>") center/12px no-repeat;
}
.ex-phase-num {
  font: 700 11px/1 var(--font-mono, ui-monospace, monospace);
  color: var(--fg-body-light);
  letter-spacing: 0.04em;
  font-variant-numeric: tabular-nums;
}
.ex-phase-row.is-on .ex-phase-num { color: var(--fg-link); }
.ex-phase-count {
  font: 600 11px/1 var(--font-body);
  color: var(--fg-body-light);
  background: var(--ut-neutral-50);
  padding: 3px 7px;
  border-radius: var(--radius-pill);
  font-variant-numeric: tabular-nums;
}
.ex-phase-row.is-on .ex-phase-count {
  background: var(--ut-blue-50);
  color: var(--fg-link);
}

.ex-side-callout {
  margin-top: auto;
  padding: 14px;
  background: var(--surface-canvas);
  border: 1px solid var(--border-divider);
  border-radius: var(--radius-md);
}
.ex-side-callout-eyebrow {
  font: 700 10px/1 var(--font-body);
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--fg-body-light);
  margin-bottom: 6px;
}
.ex-side-callout-body {
  font: 400 12px/1.45 var(--font-body);
  color: var(--fg-body);
}
.ex-side-callout-body strong { color: var(--fg-body-strong); font-weight: 700; }

/* ─── LIST ───────────────────────────────────────────────────── */
.ex-list {
  overflow-y: auto;
  padding: 22px 24px 40px;
  background: var(--surface-canvas);
}
.ex-list-group { margin-bottom: 28px; }
.ex-list-grouphead {
  display: flex;
  align-items: baseline;
  gap: 10px;
  margin-bottom: 12px;
  padding: 0 4px;
}
.ex-list-groupname {
  font: 700 13px/1 var(--font-body);
  color: var(--fg-heading-strong);
  letter-spacing: 0.04em;
  text-transform: uppercase;
}
.ex-list-groupblurb {
  font: 400 12px/1.3 var(--font-body);
  color: var(--fg-body-light);
}
.ex-list-groupcount {
  margin-left: auto;
  font: 600 11px/1 var(--font-body);
  color: var(--fg-body-light);
  font-variant-numeric: tabular-nums;
}
.ex-card {
  display: grid;
  grid-template-columns: 4px 1fr auto;
  background: var(--surface-base);
  border: 1px solid var(--border-divider);
  border-radius: var(--radius-md);
  margin-bottom: 8px;
  cursor: pointer;
  text-align: left;
  font: inherit;
  color: inherit;
  width: 100%;
  padding: 0;
  overflow: hidden;
  transition: border-color var(--duration-fast) var(--ease-out),
              box-shadow var(--duration-fast) var(--ease-out),
              transform var(--duration-fast) var(--ease-out);
}
.ex-card:hover {
  border-color: var(--mode-line);
  box-shadow: var(--shadow-sm);
}
.ex-card.is-selected {
  border-color: var(--mode-line);
  box-shadow: 0 0 0 1px var(--mode-line), var(--shadow-sm);
}
.ex-card-rail { background: var(--mode-mark); }
.ex-card-body {
  padding: 14px 16px;
  display: flex;
  flex-direction: column;
  gap: 6px;
  min-width: 0;
}
.ex-card-toprow {
  display: flex;
  align-items: center;
  gap: 10px;
  flex-wrap: wrap;
}
.ex-card-symbol {
  font: 800 11px/1 var(--font-body);
  letter-spacing: 0.04em;
  color: var(--mode-fg);
  background: var(--mode-bg);
  padding: 4px 7px;
  border-radius: var(--radius-xs);
  text-transform: uppercase;
  font-variant-numeric: tabular-nums;
}
.ex-card-tool {
  font: 700 15px/1.2 var(--font-body);
  color: var(--fg-heading-strong);
  letter-spacing: -0.005em;
  flex: 1 1 auto;
  min-width: 0;
}
.ex-card-def {
  font: 400 13px/1.45 var(--font-body);
  color: var(--fg-body);
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
}
.ex-card-meta {
  display: flex;
  align-items: center;
  gap: 8px;
  font: 400 11px/1.3 var(--font-body);
  color: var(--fg-body-light);
  margin-top: 2px;
}
.ex-card-meta-sep { opacity: 0.4; }
.ex-card-meta-label {
  text-transform: uppercase;
  letter-spacing: 0.06em;
  font-weight: 700;
  font-size: 10px;
  color: var(--fg-body-light);
  margin-right: 2px;
}
.ex-card-chev {
  align-self: center;
  padding: 0 14px 0 0;
  color: var(--icon-light);
  display: flex;
  align-items: center;
}
.ex-card.is-selected .ex-card-chev { color: var(--mode-line); }

.ex-empty {
  background: var(--surface-base);
  border: 1px dashed var(--border-divider);
  border-radius: var(--radius-md);
  padding: 32px;
  text-align: center;
  color: var(--fg-body);
}
.ex-empty-title {
  font: 700 15px/1.3 var(--font-body);
  color: var(--fg-heading-strong);
  margin-bottom: 4px;
}
.ex-empty-blurb { font: 400 13px/1.5 var(--font-body); color: var(--fg-body-light); }

/* ─── DETAIL ─────────────────────────────────────────────────── */
.ex-detail {
  background: var(--surface-base);
  border-left: 1px solid var(--border-divider);
  overflow-y: auto;
  padding: 28px 32px 40px;
  display: flex;
  flex-direction: column;
  gap: 20px;
}
/* Without this, flex shrinks each section to fit the column — squishing the
   prompt block into ~47px and visually clipping its text. Pinning shrink to 0
   lets the natural heights stack and triggers the parent's overflow-y. */
.ex-detail > * { flex-shrink: 0; }
.ex-detail-crumbs {
  font: 600 11px/1 var(--font-body);
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--fg-body-light);
  display: flex;
  gap: 8px;
  align-items: center;
}
.ex-detail-crumbs-sep { color: var(--icon-x-light); }
.ex-detail-crumbs-current { color: var(--mode-fg); }

.ex-detail-titleblock {
  display: grid;
  grid-template-columns: 56px 1fr;
  gap: 16px;
  align-items: start;
}
.ex-detail-sym {
  width: 56px; height: 56px;
  border-radius: var(--radius-md);
  background: var(--mode-bg);
  color: var(--mode-fg);
  display: grid;
  place-items: center;
  font: 800 22px/1 var(--font-body);
  letter-spacing: -0.01em;
}
.ex-detail-title {
  font: 700 24px/1.15 var(--font-body);
  color: var(--fg-heading-strong);
  margin: 0 0 8px;
  letter-spacing: -0.015em;
}
.ex-detail-def {
  font: 400 14px/1.55 var(--font-body);
  color: var(--fg-body);
  margin: 0;
}

.ex-detail-banner {
  background: var(--mode-bg);
  border-radius: var(--radius-md);
  padding: 16px 18px;
  border-left: 4px solid var(--mode-mark);
}
.ex-detail-banner-label {
  font: 700 10px/1 var(--font-body);
  text-transform: uppercase;
  letter-spacing: 0.12em;
  color: var(--mode-fg);
  margin-bottom: 6px;
  display: flex;
  align-items: center;
  gap: 6px;
}
.ex-detail-banner-label .dot {
  width: 6px; height: 6px; border-radius: 50%;
  background: var(--mode-mark);
}
.ex-detail-banner-body {
  font: 400 14px/1.55 var(--font-body);
  color: var(--mode-fg);
}
.ex-detail-banner-body strong { font-weight: 700; }

.ex-detail-meta {
  display: grid;
  grid-template-columns: 1fr 1fr;
  border: 1px solid var(--border-divider);
  border-radius: var(--radius-md);
  overflow: hidden;
}
.ex-meta-cell {
  padding: 14px 16px;
  border-right: 1px solid var(--border-divider);
  border-bottom: 1px solid var(--border-divider);
}
.ex-meta-cell:nth-child(2n) { border-right: 0; }
.ex-meta-cell:nth-last-child(-n+2) { border-bottom: 0; }
.ex-meta-cell-wide { grid-column: 1 / -1; border-right: 0; }
.ex-meta-label {
  font: 700 10px/1 var(--font-body);
  text-transform: uppercase;
  letter-spacing: 0.12em;
  color: var(--fg-body-light);
  margin-bottom: 6px;
}
.ex-meta-value {
  font: 400 13px/1.5 var(--font-body);
  color: var(--fg-body-strong);
}
.ex-muted { color: var(--fg-body-light); font-style: italic; }

.ex-detail-prompt {
  border: 1px solid var(--border-divider);
  border-radius: var(--radius-md);
  overflow: hidden;
}
.ex-detail-prompt-head {
  padding: 14px 16px;
  display: flex;
  align-items: center;
  gap: 10px;
  background: var(--surface-canvas);
  border-bottom: 1px solid var(--border-divider);
}
.ex-detail-prompt-kind {
  font: 700 10px/1 var(--font-body);
  text-transform: uppercase;
  letter-spacing: 0.1em;
  padding: 4px 8px;
  background: var(--ut-blue-50);
  color: var(--ut-blue-800);
  border-radius: var(--radius-xs);
}
.ex-detail-prompt-kind.is-tbd { background: var(--ut-yellow-100); color: var(--ut-yellow-800); }
.ex-detail-prompt-kind.is-none { background: var(--ut-neutral-50); color: var(--fg-body); }
.ex-detail-prompt-name {
  font: 700 13px/1 var(--font-body);
  color: var(--fg-heading-strong);
  letter-spacing: -0.005em;
}
.ex-detail-prompt-body-section {
  padding: 16px 18px;
}
.ex-detail-prompt-summary {
  font: 400 14px/1.6 var(--font-body);
  color: var(--fg-body-strong);
  margin: 0 0 12px;
}
.ex-detail-prompt-toggle {
  border: 1px solid var(--border-divider);
  background: var(--surface-base);
  color: var(--fg-link);
  font: 600 12px/1 var(--font-body);
  padding: 8px 12px;
  border-radius: var(--radius-sm);
  cursor: pointer;
  display: inline-flex;
  align-items: center;
  gap: 6px;
  transition: all var(--duration-fast) var(--ease-out);
}
.ex-detail-prompt-toggle:hover {
  border-color: var(--border-focus);
  background: var(--hover-bg);
}
.ex-detail-prompt-toggle .caret {
  display: inline-block;
  transition: transform var(--duration-fast) var(--ease-out);
}
.ex-detail-prompt-toggle.is-open .caret { transform: rotate(90deg); }
.ex-detail-prompt-full {
  margin-top: 14px;
  background: var(--ut-neutral-25);
  border: 1px solid var(--border-divider);
  border-radius: var(--radius-sm);
  padding: 14px 16px;
  font: 400 12px/1.55 var(--font-mono, ui-monospace, "SF Mono", Menlo, Consolas, monospace);
  color: var(--fg-body-strong);
  white-space: pre-wrap;
  max-height: 360px;
  overflow-y: auto;
}
.ex-detail-prompt-empty {
  padding: 16px 18px;
  font: 400 14px/1.55 var(--font-body);
  color: var(--fg-body);
}
.ex-detail-prompt-tbd-note {
  margin-top: 8px;
  font: 400 12px/1.4 var(--font-body);
  color: var(--fg-body-light);
  font-style: italic;
}

/* Toolbar / footer (links to other formats) */
.ex-formats {
  border-top: 1px solid var(--border-divider);
  background: var(--surface-base);
  padding: 10px 28px;
  display: flex;
  align-items: center;
  gap: 16px;
  font: 600 12px/1 var(--font-body);
  color: var(--fg-body);
}
.ex-formats-label {
  text-transform: uppercase;
  letter-spacing: 0.1em;
  font-size: 10px;
  color: var(--fg-body-light);
}
.ex-formats a {
  color: var(--fg-link);
  text-decoration: none;
  padding: 6px 10px;
  border-radius: var(--radius-xs);
  transition: background var(--duration-fast) var(--ease-out);
}
.ex-formats a:hover { background: var(--hover-bg); }
.ex-formats a.is-current {
  background: var(--selected-bg);
  color: var(--fg-link-hover);
}