/* Tokens transcribed from DESIGN.md. Inherited wholesale from WhatsApp Hub's tokens.css and extended
   with the surfaces that app never needed: the help-center reading surface (top bar, hero search,
   category cards), breadcrumb, article prose, editor chrome and the share-link surface. No new
   color, radius or font was introduced.

   TWO SURFACES, deliberately different shapes: reading (.topbar + .reading-main) is used by every
   role and spends its width on content; management (.app-shell + .sidebar) is lists and forms for
   editors. Reusing the management shell as a viewer's UI was the mistake this replaced.

   Roobert PRO is deliberately absent: it is commercially licensed (DESIGN.md § Font note). */

:root {
  --color-primary: #1c1c1e;
  --color-on-primary: #ffffff;
  --color-charcoal: #2c2c34;
  --color-brand-blue: #4262ff;
  --color-blue-pressed: #2a41b6;
  --color-success-accent: #00b473;
  --color-brand-red: #fbd4d4;
  --color-brand-red-dark: #e3c5c5;
  --color-coral-dark: #600000;
  --color-coral-light: #ffc6c6;
  --color-canvas: #ffffff;
  --color-surface: #f7f8fa;
  --color-surface-soft: #fafbfc;
  --color-hairline: #e0e2e8;
  --color-hairline-soft: #eef0f3;
  --color-hairline-strong: #c7cad5;
  --color-ink: #1c1c1e;
  --color-slate: #555a6a;
  --color-steel: #6b6f7e;
  --color-stone: #8e91a0;
  --color-muted: #a5a8b5;
  --color-surface-yellow: #fff8e0;
  --color-yellow-dark: #746019;
  --color-mint-light: #d7f5e9;

  --font-family: "Noto Sans", -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  --font-family-mono: ui-monospace, SFMono-Regular, Menlo, monospace;

  --radius-sm: 6px;
  --radius-md: 8px;
  --radius-lg: 12px;
  --radius-xl: 16px;
  --radius-full: 9999px;

  --space-xxs: 4px;
  --space-xs: 8px;
  --space-sm: 12px;
  --space-md: 16px;
  --space-lg: 20px;
  --space-xl: 24px;
  --space-xxl: 32px;
  --space-section: 48px;

  --measure-prose: 72ch;
  --measure-main: 1100px;
  --measure-reading: 820px;
  --measure-help-center: 1040px;
  --width-sidebar: 220px;
  --height-topbar: 64px;
}

* { box-sizing: border-box; }

body {
  margin: 0;
  font-family: var(--font-family);
  color: var(--color-ink);
  background: var(--color-surface);
  font-size: 16px;
  line-height: 1.5;
}

h1, h2, h3, h4 { margin: 0 0 var(--space-sm) 0; font-weight: 500; }
h1 { font-size: 28px; line-height: 1.2; letter-spacing: -0.5px; }
h2 { font-size: 22px; line-height: 1.3; }
h3 { font-size: 18px; line-height: 1.4; }

/* ---------- Management layout: sidebar + main ---------- */

.app-shell { display: flex; min-height: 100vh; align-items: stretch; }

.sidebar {
  width: var(--width-sidebar);
  flex-shrink: 0;
  background: var(--color-canvas);
  border-right: 1px solid var(--color-hairline);
  padding: var(--space-xl) var(--space-md);
  display: flex;
  flex-direction: column;
}

.sidebar-brand { font-weight: 600; font-size: 18px; margin-bottom: var(--space-md); }

/* The switcher changes everything below it, so it sits above everything it changes. */
.center-switcher { margin-bottom: var(--space-xl); }
.center-switcher select { height: 36px; font-size: 14px; padding: 0 var(--space-sm); }
.center-switcher .center-name { font-size: 14px; font-weight: 600; color: var(--color-ink); }

.sidebar-nav a {
  display: flex;
  align-items: center;
  gap: var(--space-xs);
  padding: var(--space-sm) var(--space-md);
  border-radius: var(--radius-md);
  color: var(--color-steel);
  text-decoration: none;
  font-size: 14px;
  font-weight: 500;
  margin-bottom: 2px;
}
.sidebar-nav a.active, .sidebar-nav a:hover { background: var(--color-surface); color: var(--color-ink); }

.sidebar-footer {
  margin-top: auto;
  padding-top: var(--space-md);
  border-top: 1px solid var(--color-hairline);
}

.main-content { flex: 1; padding: var(--space-xxl); max-width: var(--measure-main); min-width: 0; }

.sidebar-back {
  display: inline-flex;
  align-items: center;
  gap: var(--space-xxs);
  font-size: 13px;
  color: var(--color-steel);
  text-decoration: none;
  padding: var(--space-xxs) var(--space-xs);
  margin: 0 0 var(--space-md) calc(var(--space-xs) * -1);
  border-radius: var(--radius-sm);
}
.sidebar-back:hover { background: var(--color-surface); color: var(--color-ink); }


/* ---------- Reading surface: top bar ---------- */

.topbar {
  display: flex;
  align-items: center;
  gap: var(--space-lg);
  height: var(--height-topbar);
  padding: 0 var(--space-xl);
  background: var(--color-canvas);
  border-bottom: 1px solid var(--color-hairline);
  position: sticky;
  top: 0;
  z-index: 20;
}
.topbar-brand {
  font-weight: 600;
  font-size: 16px;
  color: var(--color-ink);
  text-decoration: none;
  white-space: nowrap;
  flex-shrink: 0;
}

.topbar-search {
  display: flex;
  align-items: center;
  gap: var(--space-xs);
  flex: 1;
  max-width: 520px;
  margin: 0 auto;
  padding: 0 var(--space-md);
  background: var(--color-surface);
  border: 1px solid var(--color-hairline);
  border-radius: var(--radius-full);
  color: var(--color-stone);
  height: 40px;
}
.topbar-search:focus-within { border-color: var(--color-hairline-strong); background: var(--color-canvas); }
.topbar-search input {
  border: none;
  background: none;
  height: 38px;
  padding: 0;
  font-size: 14px;
  width: 100%;
  color: var(--color-ink);
}
.topbar-search input:focus { outline: none; }

/* Native <details> dropdown: no modal library, no client-side framework. */
.topbar-account { position: relative; flex-shrink: 0; }
.topbar-account > summary {
  list-style: none;
  cursor: pointer;
  display: flex;
  align-items: center;
  gap: var(--space-xxs);
  padding: var(--space-xs) var(--space-sm);
  border-radius: var(--radius-full);
  font-size: 14px;
  font-weight: 500;
  color: var(--color-ink);
}
.topbar-account > summary::-webkit-details-marker { display: none; }
.topbar-account > summary:hover { background: var(--color-surface); }
.topbar-account-name { max-width: 160px; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.topbar-chevron { color: var(--color-stone); font-size: 12px; }

.topbar-menu {
  position: absolute;
  right: 0;
  top: calc(100% + var(--space-xs));
  min-width: 260px;
  background: var(--color-canvas);
  border: 1px solid var(--color-hairline);
  border-radius: var(--radius-lg);
  padding: var(--space-md);
  /* One of the two places this system uses a real shadow: it must visibly float above the page. */
  box-shadow: 0 8px 24px rgba(28, 28, 30, 0.12);
}
.topbar-menu-identity {
  font-size: 13px;
  color: var(--color-stone);
  padding-bottom: var(--space-sm);
  margin-bottom: var(--space-sm);
  border-bottom: 1px solid var(--color-hairline-soft);
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  gap: var(--space-xs);
}
.topbar-menu-section { margin-top: var(--space-sm); }
.topbar-menu-section select { height: 40px; font-size: 14px; }
.topbar-menu-link {
  display: block;
  padding: var(--space-xs) var(--space-sm);
  margin: 0 calc(var(--space-sm) * -1);
  border-radius: var(--radius-md);
  color: var(--color-ink);
  text-decoration: none;
  font-size: 14px;
  font-weight: 500;
}
.topbar-menu-link:hover { background: var(--color-surface); }

.reading-main {
  max-width: var(--measure-help-center);
  margin: 0 auto;
  padding: var(--space-xxl) var(--space-xl);
}

/* ---------- Help-center home ---------- */

.hero { text-align: center; padding: var(--space-xxl) 0 var(--space-section) 0; }
.hero h1 { font-size: 32px; margin-bottom: var(--space-lg); }
.hero-search {
  display: flex;
  gap: var(--space-sm);
  max-width: 560px;
  margin: 0 auto;
}
.hero-search input { height: 48px; border-radius: var(--radius-full); padding: 0 var(--space-lg); }

.category-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
  gap: var(--space-lg);
}
.category-card {
  background: var(--color-canvas);
  border: 1px solid var(--color-hairline-soft);
  border-radius: var(--radius-xl);
  padding: var(--space-xl);
}
.category-card-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-sm);
  margin-bottom: var(--space-md);
}
.category-card-header h2 {
  font-size: 18px;
  font-weight: 600;
  margin: 0;
  display: flex;
  align-items: center;
  gap: var(--space-xs);
  color: var(--color-ink);
}
.category-card-header h2 a { color: inherit; text-decoration: none; }
.category-card-header h2 a:hover { text-decoration: underline; }
.category-card-header .count {
  font-size: 13px;
  color: var(--color-steel);
  background: var(--color-surface);
  border-radius: var(--radius-full);
  padding: 2px 10px;
}

.category-card-subs { display: flex; flex-wrap: wrap; gap: var(--space-xs); margin-bottom: var(--space-md); }
.subcategory-chip {
  display: inline-flex;
  align-items: center;
  gap: var(--space-xxs);
  font-size: 13px;
  font-weight: 500;
  color: var(--color-steel);
  text-decoration: none;
  background: var(--color-surface);
  border-radius: var(--radius-full);
  padding: var(--space-xxs) var(--space-sm);
}
.subcategory-chip:hover { color: var(--color-ink); }
.subcategory-chip .count { color: var(--color-muted); }

.article-links { list-style: none; margin: 0; padding: 0; }
.article-links a {
  display: flex;
  align-items: center;
  gap: var(--space-xs);
  padding: var(--space-xs) var(--space-sm);
  margin: 0 calc(var(--space-sm) * -1);
  min-height: 40px;
  border-radius: var(--radius-md);
  color: var(--color-slate);
  text-decoration: none;
  font-size: 14px;
}
.article-links a:hover { background: var(--color-surface); color: var(--color-ink); }
.article-links svg { color: var(--color-muted); flex-shrink: 0; }

.category-card-more {
  display: inline-flex;
  align-items: center;
  gap: var(--space-xxs);
  margin-top: var(--space-md);
  font-size: 13px;
  font-weight: 500;
  color: var(--color-steel);
  text-decoration: none;
}
.category-card-more:hover { color: var(--color-ink); }

/* Search hits: SQLite's snippet(), rendered as text nodes with the matches wrapped in <mark>. */
mark { background: var(--color-surface-yellow); color: var(--color-yellow-dark); border-radius: var(--radius-sm); padding: 0 2px; }

/* ---------- Article sheet (reading) ---------- */

.article-sheet {
  background: var(--color-canvas);
  border: 1px solid var(--color-hairline-soft);
  border-radius: var(--radius-xl);
  padding: var(--space-section) var(--space-xxl);
  max-width: var(--measure-reading);
  margin: 0 auto;
}
.article-toolbar {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: var(--space-md);
  margin-bottom: var(--space-lg);
}

/* ---------- Breadcrumb ---------- */

.breadcrumb { font-size: 13px; color: var(--color-stone); margin-bottom: var(--space-xs); }
.breadcrumb a { color: var(--color-stone); text-decoration: none; padding: 2px 6px; border-radius: var(--radius-sm); }
.breadcrumb a:hover { background: var(--color-surface); color: var(--color-ink); }
.breadcrumb .sep { color: var(--color-muted); margin: 0 2px; }

/* ---------- Cards, buttons, forms ---------- */

.card {
  background: var(--color-canvas);
  border: 1px solid var(--color-hairline-soft);
  border-radius: var(--radius-xl);
  padding: var(--space-xl);
  margin-bottom: var(--space-xl);
}
.card-title { font-size: 18px; font-weight: 500; line-height: 1.4; }

.btn {
  display: inline-flex;
  align-items: center;
  gap: var(--space-xs);
  font-family: var(--font-family);
  font-size: 14px;
  font-weight: 500;
  border-radius: var(--radius-full);
  padding: 12px 24px;
  border: none;
  cursor: pointer;
  text-decoration: none;
  white-space: nowrap;
}
.btn-primary { background: var(--color-primary); color: var(--color-on-primary); }
.btn-primary:hover { background: var(--color-charcoal); }
.btn-secondary { background: transparent; color: var(--color-ink); border: 1px solid var(--color-hairline-strong); }
.btn-secondary:hover { background: var(--color-surface); }
.btn-danger { background: var(--color-brand-red-dark); color: var(--color-coral-dark); }
.btn-sm { padding: var(--space-xs) var(--space-md); font-size: 13px; }
.btn:disabled { opacity: 0.55; cursor: default; }

input[type="text"], input[type="email"], input[type="url"], input[type="datetime-local"], textarea, select {
  font-family: var(--font-family);
  font-size: 16px;
  color: var(--color-ink);
  background: var(--color-canvas);
  border: 1px solid var(--color-hairline-strong);
  border-radius: var(--radius-md);
  padding: var(--space-sm) var(--space-md);
  height: 44px;
  width: 100%;
}
textarea { height: auto; min-height: 88px; }
label { display: block; font-size: 13px; font-weight: 600; color: var(--color-slate); margin-bottom: var(--space-xxs); }
.field { margin-bottom: var(--space-md); }

.filters-bar {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(180px, 1fr));
  gap: var(--space-md) var(--space-lg);
  align-items: end;
}
.filters-bar .field { margin-bottom: 0; min-width: 0; }

/* In-app interactive text: same ink as its surroundings, with a hover highlight — not a blue link. */
.link-button {
  background: none;
  border: none;
  padding: 2px 6px;
  margin: -2px -6px;
  border-radius: var(--radius-sm);
  font: inherit;
  color: var(--color-ink);
  cursor: pointer;
  text-decoration: none;
  display: inline-flex;
  align-items: center;
  gap: var(--space-xxs);
}
.link-button:hover { background: var(--color-surface); }

.toolbar { display: flex; justify-content: space-between; align-items: center; gap: var(--space-md); margin-bottom: var(--space-lg); }
.toolbar-actions { display: flex; gap: var(--space-sm); align-items: center; }
.muted { color: var(--color-stone); font-size: 13px; }

/* ---------- Tables (members, share links) ---------- */

table { width: 100%; border-collapse: collapse; background: var(--color-canvas); border-radius: var(--radius-md); overflow: hidden; }
th, td { text-align: left; padding: var(--space-md) var(--space-lg); font-size: 14px; border-bottom: 1px solid var(--color-hairline-soft); }
th { color: var(--color-steel); font-weight: 500; font-size: 11px; text-transform: uppercase; letter-spacing: 0.5px; }
tr.revoked td { color: var(--color-muted); text-decoration: line-through; }
tr.revoked td .btn, tr.revoked td code { text-decoration: none; }

/* ---------- Badges ---------- */

.badge { display: inline-block; font-size: 13px; font-weight: 600; border-radius: var(--radius-full); padding: 4px 10px; }
.badge-draft { background: var(--color-surface-yellow); color: var(--color-yellow-dark); }
.badge-published { background: var(--color-mint-light); color: var(--color-success-accent); }
.badge-owner { background: var(--color-primary); color: var(--color-on-primary); }
.badge-editor { background: var(--color-surface-yellow); color: var(--color-yellow-dark); }
.badge-viewer { background: var(--color-surface); color: var(--color-steel); border: 1px solid var(--color-hairline); }

/* ---------- Banners & empty states ---------- */

.error-banner { background: var(--color-coral-light); color: var(--color-coral-dark); padding: var(--space-md); border-radius: var(--radius-md); margin-bottom: var(--space-md); }
.success-banner { background: var(--color-mint-light); color: var(--color-success-accent); padding: var(--space-md); border-radius: var(--radius-md); margin-bottom: var(--space-md); }
.warning-banner { background: var(--color-surface-yellow); color: var(--color-yellow-dark); padding: var(--space-md); border-radius: var(--radius-md); margin-bottom: var(--space-md); }

.empty-state { padding: var(--space-xl) 0; }
.empty-state .card-title { margin-bottom: var(--space-xxs); }
.empty-state .muted { margin-bottom: var(--space-md); }

/* ---------- Article list (a tree plus cards — never a table) ---------- */

.article-card {
  display: block;
  background: var(--color-canvas);
  border: 1px solid var(--color-hairline-soft);
  border-radius: var(--radius-xl);
  padding: var(--space-lg) var(--space-xl);
  margin-bottom: var(--space-md);
  text-decoration: none;
  color: var(--color-ink);
}
.article-card:hover { border-color: var(--color-hairline-strong); }
.article-card .article-card-title { font-size: 18px; font-weight: 500; display: flex; align-items: center; gap: var(--space-sm); }
.article-card .article-card-excerpt { color: var(--color-slate); font-size: 14px; margin-top: var(--space-xxs); }
.article-card .article-card-meta { color: var(--color-stone); font-size: 13px; margin-top: var(--space-xs); }

/* ---------- Article prose: ONE block, used by the reader AND the editor canvas ---------- */

.prose, .ql-editor {
  font-family: var(--font-family);
  font-size: 17px;
  line-height: 1.7;
  color: var(--color-ink);
  max-width: var(--measure-prose);
}
.prose > *:first-child, .ql-editor > *:first-child { margin-top: 0; }
.prose p, .ql-editor p { margin: 0 0 var(--space-md) 0; }
.prose h2, .ql-editor h2 { font-size: 24px; font-weight: 600; line-height: 1.3; margin: var(--space-xl) 0 var(--space-xs) 0; }
.prose h3, .ql-editor h3 { font-size: 19px; font-weight: 600; line-height: 1.4; margin: var(--space-xl) 0 var(--space-xs) 0; }
.prose h4, .ql-editor h4 { font-size: 17px; font-weight: 600; line-height: 1.4; margin: var(--space-xl) 0 var(--space-xs) 0; }
.prose ul, .prose ol, .ql-editor ul, .ql-editor ol { margin: 0 0 var(--space-md) 0; padding-left: 20px; }
.prose li, .ql-editor li { margin-bottom: var(--space-xxs); }
.prose blockquote, .ql-editor blockquote {
  margin: 0 0 var(--space-md) 0;
  padding-left: var(--space-md);
  border-left: 3px solid var(--color-hairline-strong);
  color: var(--color-slate);
  font-style: normal;
}
.prose code, .ql-editor code {
  font-family: var(--font-family-mono);
  font-size: 14px;
  background: var(--color-surface);
  border-radius: var(--radius-sm);
  padding: 2px 5px;
}
.prose pre, .ql-editor pre {
  font-family: var(--font-family-mono);
  font-size: 14px;
  line-height: 1.6;
  background: var(--color-surface);
  padding: var(--space-md);
  border-radius: var(--radius-md);
  overflow-x: auto;
}
.prose pre code, .ql-editor pre code { background: none; padding: 0; }
.prose img, .ql-editor img {
  max-width: 100%;
  height: auto;
  border-radius: var(--radius-lg);
  border: 1px solid var(--color-hairline-soft);
  margin: var(--space-lg) 0;
}
.prose figure, .ql-editor figure { margin: var(--space-lg) 0; }
.prose figcaption, .ql-editor figcaption { font-size: 13px; color: var(--color-stone); text-align: center; }
.prose hr, .ql-editor hr { border: none; border-top: 1px solid var(--color-hairline); margin: var(--space-xl) 0; }
/* The documented exception to "no blue underlined links": inside a document, a link must look like one. */
.prose a, .ql-editor a { color: var(--color-brand-blue); text-decoration: underline; }
.prose a:active, .ql-editor a:active { color: var(--color-blue-pressed); }
.prose table, .ql-editor table { margin-bottom: var(--space-md); }
.prose-scroll { overflow-x: auto; }

.article-header { margin-bottom: var(--space-xl); }
.article-header h1 { margin-bottom: var(--space-xs); }
.article-meta { display: flex; align-items: center; gap: var(--space-sm); color: var(--color-stone); font-size: 13px; }

/* ---------- Editor chrome: toolbar + canvas read as ONE control ---------- */

.editor-shell { margin-bottom: var(--space-lg); }
.editor-shell .ql-toolbar.ql-snow {
  background: var(--color-surface-soft);
  border: 1px solid var(--color-hairline);
  border-radius: var(--radius-md) var(--radius-md) 0 0;
  padding: var(--space-xs);
  font-family: var(--font-family);
}
.editor-shell .ql-container.ql-snow {
  background: var(--color-canvas);
  border: 1px solid var(--color-hairline);
  border-top: none;
  border-radius: 0 0 var(--radius-md) var(--radius-md);
  font-family: var(--font-family);
}
.editor-shell .ql-editor { padding: var(--space-xl); min-height: 420px; }
.editor-shell .ql-editor.ql-blank::before { color: var(--color-muted); font-style: normal; left: var(--space-xl); right: var(--space-xl); }
.ql-snow .ql-stroke { stroke: var(--color-steel); }
.ql-snow .ql-fill { fill: var(--color-steel); }
.ql-snow.ql-toolbar button { width: 32px; height: 32px; border-radius: var(--radius-sm); }
.ql-snow.ql-toolbar button:hover { background: var(--color-surface); }
.ql-snow.ql-toolbar button:hover .ql-stroke { stroke: var(--color-ink); }
.ql-snow.ql-toolbar button:hover .ql-fill { fill: var(--color-ink); }
.ql-snow.ql-toolbar button.ql-active { background: var(--color-surface); }
.ql-snow.ql-toolbar button.ql-active .ql-stroke { stroke: var(--color-ink); }
.ql-snow.ql-toolbar button.ql-active .ql-fill { fill: var(--color-ink); }
.ql-snow.ql-toolbar .ql-formats { margin-right: var(--space-sm); padding-right: var(--space-sm); border-right: 1px solid var(--color-hairline); }
.ql-snow.ql-toolbar .ql-formats:last-child { border-right: none; }
.ql-snow .ql-picker { color: var(--color-steel); }
.ql-snow .ql-tooltip { border-radius: var(--radius-md); border-color: var(--color-hairline); box-shadow: 0 4px 16px rgba(28, 28, 30, 0.12); }

/* Upload states are part of the design: a placeholder at final width, and a dismissible failure. */
.editor-upload-placeholder {
  display: block;
  width: 100%;
  height: 160px;
  background: var(--color-surface);
  border-radius: var(--radius-lg);
  border: 1px solid var(--color-hairline-soft);
}
.editor-upload-error {
  background: var(--color-coral-light);
  color: var(--color-coral-dark);
  border-radius: var(--radius-md);
  padding: var(--space-sm) var(--space-md);
  font-size: 14px;
  margin-bottom: var(--space-sm);
  display: flex;
  justify-content: space-between;
  gap: var(--space-md);
}
/* Save state sits next to the primary button, inline — never a toast that can be missed. */
.save-state { color: var(--color-stone); font-size: 13px; }

/* ---------- Share-link surface: the one place this system raises its voice ---------- */

.share-token-field {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  background: var(--color-surface);
  color: var(--color-ink);
  font-family: var(--font-family-mono);
  font-size: 14px;
  border: 1px dashed var(--color-hairline-strong);
  border-radius: var(--radius-md);
  padding: var(--space-sm) var(--space-md);
  margin: var(--space-md) 0;
}
.share-token-field input {
  border: none;
  background: none;
  font-family: var(--font-family-mono);
  font-size: 14px;
  height: auto;
  padding: 0;
  flex: 1;
  min-width: 0;
}
.share-token-field input:focus { outline: none; }
td code { font-family: var(--font-family-mono); font-size: 13px; color: var(--color-steel); }

/* ---------- The public share page: one column, starved of context ---------- */

.public-page { background: var(--color-surface); min-height: 100vh; }
.public-header {
  background: var(--color-canvas);
  border-bottom: 1px solid var(--color-hairline);
  padding: var(--space-md) var(--space-xl);
}
.public-header .center-name { font-weight: 600; font-size: 16px; }
.public-header .shared-note { color: var(--color-stone); font-size: 13px; }
.public-body { max-width: var(--measure-reading); margin: 0 auto; padding: var(--space-section) var(--space-md); }
.public-sheet {
  background: var(--color-canvas);
  border: 1px solid var(--color-hairline-soft);
  border-radius: var(--radius-xl);
  padding: var(--space-section) var(--space-xl);
}

/* ---------- Responsive ---------- */

@media (max-width: 1199px) {
  .app-shell { flex-wrap: wrap; }
  
@media (max-width: 899px) {
  /* The top bar drops the search into its own row rather than squeezing it to nothing. */
  .topbar { height: auto; flex-wrap: wrap; padding: var(--space-sm) var(--space-md); row-gap: var(--space-sm); }
  .topbar-search { order: 3; flex-basis: 100%; max-width: none; margin: 0; }
  .topbar-account { margin-left: auto; }
  .reading-main { padding: var(--space-lg) var(--space-md); }
  .hero { padding: var(--space-lg) 0 var(--space-xl) 0; }
  .hero h1 { font-size: 24px; }
  .hero-search { flex-direction: column; }
  .category-grid { grid-template-columns: 1fr; }
  .article-sheet { padding: var(--space-xl) var(--space-md); border-radius: 0; border-left: none; border-right: none; }
  .article-toolbar { flex-direction: column; }
  .app-shell { flex-direction: column; }
  .sidebar {
    width: 100%;
    border-right: none;
    border-bottom: 1px solid var(--color-hairline);
    padding: var(--space-md);
  }
  .sidebar-footer { margin-top: var(--space-md); }
  .main-content { padding: var(--space-lg) var(--space-md); }
  .ql-snow.ql-toolbar button { width: 40px; height: 40px; }
  .editor-shell .ql-editor { padding: var(--space-md); }
  .public-body { padding: var(--space-lg) var(--space-md); }
  .public-sheet { padding: var(--space-xl) var(--space-md); }
  /* The reading experience does not shrink — only the chrome around it does. */
  .prose img, .ql-editor img { border-radius: 0; border-left: none; border-right: none; }
  .toolbar { flex-direction: column; align-items: stretch; }
}

/* Native disclosure used for the nav and tree on narrow screens — no modal library, no framework. */
details > summary { cursor: pointer; }