:root {
  --color-bg: #fbfbfc;
  --color-panel: #ffffff;
  --color-panel-alt: #f3f4f7;
  --color-text: #15171c;
  --color-text-muted: #4b5260;
  --color-border: #d8dbe2;
  --color-border-strong: #8a91a0;
  --color-accent: #1d4ed8;
  --color-accent-hover: #1e40af;
  --color-accent-soft: #c7d7ff;
  --color-accent-fg: #ffffff;
  --color-danger: #a01a14;
  --color-danger-bg: #fde8e6;
  --color-success: #0e6a40;
  --color-success-bg: #d6f0e2;
  --color-warning: #6f4200;
  --color-warning-bg: #fff3cd;
  --color-focus: #1d4ed8;
  --color-shadow: 0 1px 3px rgba(15, 23, 42, 0.06), 0 4px 12px rgba(15, 23, 42, 0.08);
  --radius: 8px;
  --radius-lg: 12px;
  --font-sans: system-ui, -apple-system, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  --font-mono: ui-monospace, "SFMono-Regular", "Cascadia Mono", Consolas, "Liberation Mono", monospace;
}

:root[data-theme="dark"],
:root[data-theme="auto"]:where(:not([data-forced-light])) {
  /* Auto picks dark only when the system prefers it (media query below). */
}

@media (prefers-color-scheme: dark) {
  :root[data-theme="auto"] {
    --color-bg: #11141a;
    --color-panel: #181c25;
    --color-panel-alt: #20242f;
    --color-text: #f0f2f6;
    --color-text-muted: #b6bcc9;
    --color-border: #3a4150;
    --color-border-strong: #687287;
    --color-accent: #9bc1ff;
    --color-accent-hover: #b9d2ff;
    --color-accent-soft: #1f3f6d;
    --color-accent-fg: #07101f;
    --color-danger: #ff9a93;
    --color-danger-bg: #3c1b1a;
    --color-success: #a5edc6;
    --color-success-bg: #143324;
    --color-warning: #ffe19a;
    --color-warning-bg: #3a2a07;
    --color-focus: #b9d2ff;
    --color-shadow: 0 1px 3px rgba(0, 0, 0, 0.4), 0 4px 12px rgba(0, 0, 0, 0.4);
  }
}

:root[data-theme="dark"] {
  --color-bg: #11141a;
  --color-panel: #181c25;
  --color-panel-alt: #20242f;
  --color-text: #f0f2f6;
  --color-text-muted: #b6bcc9;
  --color-border: #3a4150;
  --color-border-strong: #687287;
  --color-accent: #9bc1ff;
  --color-accent-hover: #b9d2ff;
  --color-accent-soft: #1f3f6d;
  --color-accent-fg: #07101f;
  --color-danger: #ff9a93;
  --color-danger-bg: #3c1b1a;
  --color-success: #a5edc6;
  --color-success-bg: #143324;
  --color-warning: #ffe19a;
  --color-warning-bg: #3a2a07;
  --color-focus: #b9d2ff;
  --color-shadow: 0 1px 3px rgba(0, 0, 0, 0.4), 0 4px 12px rgba(0, 0, 0, 0.4);
}

* { box-sizing: border-box; }
html, body { margin: 0; padding: 0; height: 100%; }
html { scroll-padding-top: 80px; }

.sr-only {
  position: absolute !important;
  width: 1px !important; height: 1px !important;
  padding: 0 !important; margin: -1px !important;
  overflow: hidden !important; clip: rect(0,0,0,0) !important;
  white-space: nowrap !important; border: 0 !important;
}

body {
  font-family: var(--font-sans);
  background: var(--color-bg);
  color: var(--color-text);
  line-height: 1.5;
  -webkit-text-size-adjust: 100%;
  -webkit-font-smoothing: antialiased;
}

a {
  color: var(--color-accent);
  text-decoration: underline;
  text-underline-offset: 2px;
  text-decoration-thickness: 1px;
}
a:hover { color: var(--color-accent-hover); }

button, .btn {
  font: inherit;
  cursor: pointer;
  border: 1px solid var(--color-border-strong);
  background: var(--color-panel);
  color: var(--color-text);
  border-radius: var(--radius);
  padding: 0.5rem 0.9rem;
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  transition: background-color 80ms ease, border-color 80ms ease, color 80ms ease;
}
button:hover, .btn:hover { background: var(--color-panel-alt); }
button:active, .btn:active { transform: translateY(0.5px); }
button[disabled], .btn[disabled] { opacity: 0.7; cursor: not-allowed; }
button[aria-busy="true"] { cursor: progress; }

.btn-primary {
  background: var(--color-accent);
  color: var(--color-accent-fg);
  border-color: var(--color-accent);
}
.btn-primary:hover { background: var(--color-accent-hover); border-color: var(--color-accent-hover); }
.btn-ghost { border-color: transparent; background: transparent; }
.btn-ghost:hover { background: var(--color-panel-alt); }
.btn-danger {
  color: var(--color-danger);
  border-color: var(--color-danger);
  background: transparent;
}
.btn-danger:hover { background: var(--color-danger-bg); }
.btn-block { width: 100%; justify-content: center; }
.btn-sm { padding: 0.3rem 0.6rem; font-size: 0.875rem; }

input, textarea, select {
  font: inherit;
  background: var(--color-panel);
  color: var(--color-text);
  border: 1px solid var(--color-border-strong);
  border-radius: var(--radius);
  padding: 0.55rem 0.7rem;
  width: 100%;
}
input[type="checkbox"],
input[type="radio"] {
  width: auto;
  min-width: 1.5rem;
  min-height: 1.5rem;
  accent-color: var(--color-accent);
}
textarea { min-height: 5rem; resize: vertical; }

input:focus, textarea:focus, select:focus, button:focus-visible, a:focus-visible, [tabindex]:focus-visible {
  outline: 3px solid var(--color-focus);
  outline-offset: 2px;
  /* Inner ring guarantees visibility on every background — outline alone can vanish
     when the focused element shares the focus colour (active toolbar buttons). */
  box-shadow: 0 0 0 5px var(--color-panel);
}
.editor-toolbar button.is-active:focus-visible {
  outline-color: var(--color-panel);
  box-shadow: 0 0 0 5px var(--color-focus);
}

.skip-link {
  position: absolute;
  left: -10000px;
  top: auto;
}
.skip-link:focus {
  left: 8px;
  top: 8px;
  background: var(--color-accent);
  color: var(--color-accent-fg);
  padding: 0.5rem 0.75rem;
  z-index: 1000;
  border-radius: var(--radius);
}

.app-header {
  position: sticky;
  top: 0;
  z-index: 10;
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 0.6rem;
  padding: 0.6rem 1rem;
  background: var(--color-panel);
  border-bottom: 1px solid var(--color-border);
}
.brand {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  font-weight: 600;
  text-decoration: none;
  color: var(--color-text);
}
.brand-mark { width: 1.4rem; height: 1.4rem; color: var(--color-accent); }
.brand-name { font-size: 1.05rem; }
.app-nav { display: flex; align-items: center; justify-content: flex-end; gap: 0.6rem; flex-wrap: wrap; }
.theme-toggle {
  width: 2.5rem; height: 2.5rem; padding: 0; justify-content: center;
}
.theme-icon { display: inline-block; font-size: 1.2rem; line-height: 1; }

.app-main {
  min-height: calc(100vh - 56px);
  padding: 2rem 1rem 4rem;
  max-width: 1200px;
  margin: 0 auto;
  width: 100%;
  /* Skip-link target: keep clear of the sticky header when scrolled into view. */
  scroll-margin-top: 80px;
}
.app-main:focus { outline: none; }

.card {
  background: var(--color-panel);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: 1.5rem;
  box-shadow: var(--color-shadow);
}

.field { display: flex; flex-direction: column; gap: 0.35rem; margin-bottom: 0.9rem; }
.field-label {
  font-weight: 500;
  font-size: 0.95rem;
}
.field-help {
  font-size: 0.85rem;
  color: var(--color-text-muted);
}
.field-error {
  font-size: 0.85rem;
  color: var(--color-danger);
  background: var(--color-danger-bg);
  padding: 0.4rem 0.6rem;
  border-radius: var(--radius);
}

.callout {
  border-left: 4px solid var(--color-accent);
  background: var(--color-accent-soft);
  color: var(--color-text);
  padding: 0.75rem 1rem;
  border-radius: var(--radius);
  margin: 1rem 0;
}
.callout.warning { border-left-color: var(--color-warning); background: var(--color-warning-bg); color: var(--color-text); }
.callout.danger { border-left-color: var(--color-danger); background: var(--color-danger-bg); color: var(--color-text); }
.callout.success { border-left-color: var(--color-success); background: var(--color-success-bg); color: var(--color-text); }

.auth-page {
  max-width: 440px;
  margin: 4rem auto;
}
.auth-page h1 { margin-top: 0; font-size: 1.5rem; }
.auth-page .form-actions {
  display: flex; gap: 0.6rem; align-items: center; justify-content: space-between;
  flex-wrap: wrap;
  margin-top: 1rem;
}

.toast-region {
  position: fixed;
  bottom: 1rem;
  right: 1rem;
  left: auto;
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
  z-index: 1000;
  pointer-events: none;
  max-width: calc(100vw - 2rem);
}
@media (max-width: 500px) {
  /* At narrow widths or high zoom, span the bottom edge so toasts don't bury content. */
  .toast-region { left: 1rem; right: 1rem; max-width: none; }
  .toast { max-width: none; }
}
.toast {
  background: var(--color-panel);
  border: 1px solid var(--color-border-strong);
  padding: 0.6rem 0.9rem;
  border-radius: var(--radius);
  box-shadow: var(--color-shadow);
  max-width: 22rem;
  pointer-events: auto;
}
.toast.success { border-color: var(--color-success); }
.toast.error { border-color: var(--color-danger); }
.toast.warning { border-color: var(--color-warning); }

/* ------- Dashboard ------- */
.dashboard h1 { margin-top: 0; }
.dashboard-toolbar {
  display: flex; gap: 0.6rem; align-items: center; margin-bottom: 1.2rem; flex-wrap: wrap;
}
.dashboard-toolbar .filler { flex: 1; }
.doc-grid {
  display: grid;
  gap: 0.9rem;
  grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
}
.doc-card {
  display: flex;
  flex-direction: column;
  gap: 0.6rem;
  background: var(--color-panel);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: 1rem;
  box-shadow: var(--color-shadow);
}
.doc-card h2 { margin: 0; font-size: 1.05rem; }
.doc-card a.doc-link {
  text-decoration: none; color: var(--color-text);
}
.doc-card a.doc-link:hover { text-decoration: underline; }
.doc-meta {
  font-size: 0.85rem;
  color: var(--color-text-muted);
}
.doc-card-actions {
  display: flex; gap: 0.4rem; flex-wrap: wrap;
}

/* ------- Editor ------- */
.editor-shell {
  display: grid;
  grid-template-rows: auto auto 1fr;
  gap: 0.5rem;
  /* `min-height` (not `height`) lets the shell grow under 200% text zoom and at
     narrow widths instead of collapsing the editor surface to a sliver. */
  min-height: calc(100vh - 56px - 4rem);
}
.editor-meta {
  display: flex; flex-wrap: wrap; align-items: center; gap: 0.5rem;
  min-width: 0;
}
.editor-meta > * { min-width: 0; }
.editor-meta .title-input {
  font-size: 1.4rem; font-weight: 600;
  padding-left: 0.4rem;
  background: var(--color-panel);
  /* Keep a visible border at rest so the input meets 1.4.11 Non-text Contrast (≥3:1). */
  border: 1px solid var(--color-border-strong);
  min-width: 0;
  flex: 1 1 14rem;
}
/* Zero-height full-width item: forces a flex line break so the title above keeps
   the whole row and long titles are shown in full instead of being clipped. */
.editor-meta .meta-break { flex: 0 0 100%; height: 0; margin: 0; }
/* Pushes presence + action buttons to the right of the status line. */
.editor-meta .meta-spacer { flex: 1 1 0; min-width: 0; }
.editor-meta .title-input:hover {
  background: var(--color-panel-alt);
}
.editor-meta .title-input[readonly] {
  background: var(--color-panel-alt);
  cursor: default;
}
.editor-status {
  display: flex; align-items: center; gap: 0.4rem;
  font-size: 0.85rem; color: var(--color-text-muted);
}
.editor-status .dot {
  display: inline-block; width: 0.55rem; height: 0.55rem; border-radius: 50%;
  background: var(--color-text-muted);
}
.editor-status .dot.connected { background: var(--color-success); }
.editor-status .dot.offline { background: var(--color-warning); }
.editor-status .dot.error { background: var(--color-danger); }
.presence {
  display: flex; align-items: center; gap: 0.3rem;
}
.presence-avatar {
  width: 1.6rem; height: 1.6rem; border-radius: 50%;
  display: inline-flex; align-items: center; justify-content: center;
  font-size: 0.75rem; font-weight: 600;
  color: #fff;
  border: 2px solid var(--color-panel);
  margin-left: -0.4rem;
  position: relative;
}
.presence-avatar:first-child { margin-left: 0; }
/* Guests get two redundant non-colour cues so the distinction does not rely on
   any single visual property and contrast is guaranteed regardless of the
   randomly-assigned avatar fill colour:
   1) a dashed border in the panel colour (matches the gap to neighbours)
   2) a small "G" badge in the bottom-right corner with panel-coloured ring
   The badge is a real DOM element rather than a pseudo-element because some
   screen readers (VoiceOver, TalkBack) include ::before/::after `content` in
   the accessible name. The DOM element carries aria-hidden so it is never
   announced; the only spoken cue remains the sr-only "(guest)" text. */
.presence-avatar.is-guest {
  border-style: dashed;
}
.presence-avatar .guest-badge {
  position: absolute;
  right: -0.25rem;
  bottom: -0.25rem;
  width: 0.85rem;
  height: 0.85rem;
  border-radius: 50%;
  font-size: 0.55rem;
  font-weight: 700;
  line-height: 0.85rem;
  text-align: center;
  background: var(--color-panel);
  color: var(--color-text);
  border: 1px solid var(--color-border-strong);
}

.editor-toolbar {
  display: flex; flex-wrap: wrap; gap: 0.25rem; padding: 0.4rem 0.5rem;
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  background: var(--color-panel);
}
.editor-toolbar button {
  padding: 0.3rem 0.55rem;
  border-radius: 6px;
  border-color: transparent;
  background: transparent;
}
.editor-toolbar button:hover { background: var(--color-panel-alt); }
.editor-toolbar button.is-active {
  background: var(--color-accent);
  color: var(--color-accent-fg);
  border-color: var(--color-accent);
}
.editor-toolbar button {
  min-width: 2rem;
  min-height: 2rem;
}
.editor-toolbar .sep {
  width: 1px; align-self: stretch; background: var(--color-border); margin: 0 0.2rem;
}

.editor-surface {
  border: 1px solid var(--color-border-strong);
  border-radius: var(--radius);
  background: var(--color-panel);
  padding: 2rem 3rem;
  overflow-y: auto;
  /* When ProseMirror scrolls focus into view, leave room for our outline + ring. */
  scroll-padding-top: 1rem;
  scroll-padding-bottom: 1rem;
}
.editor-surface:focus-within {
  outline: 3px solid var(--color-focus);
  outline-offset: 2px;
  box-shadow: 0 0 0 5px var(--color-panel);
}
.ProseMirror {
  min-height: 100%;
  outline: none;
}
.ProseMirror p { margin: 0.4rem 0; }
.ProseMirror h1 { font-size: 1.8rem; }
.ProseMirror h2 { font-size: 1.45rem; }
.ProseMirror h3 { font-size: 1.2rem; }
.ProseMirror ul, .ProseMirror ol { padding-left: 1.5rem; }
.ProseMirror blockquote {
  border-left: 3px solid var(--color-border-strong);
  padding-left: 0.75rem; color: var(--color-text-muted);
}
.ProseMirror code {
  background: var(--color-panel-alt);
  padding: 0.1rem 0.3rem; border-radius: 4px;
  font-family: var(--font-mono); font-size: 0.92em;
}
.ProseMirror pre {
  background: var(--color-panel-alt);
  padding: 0.75rem; border-radius: var(--radius);
  font-family: var(--font-mono); font-size: 0.92em;
  overflow-x: auto;
}
.ProseMirror table {
  border-collapse: collapse;
  margin: 0.5rem 0;
  width: 100%;
}
.ProseMirror caption {
  caption-side: top;
  text-align: left;
  font-weight: 600;
  padding: 0.2rem 0;
  color: var(--color-text);
}
.ProseMirror th, .ProseMirror td {
  border: 1px solid var(--color-border-strong);
  padding: 0.3rem 0.5rem;
  min-width: 4rem;
}
.ProseMirror th { background: var(--color-panel-alt); }
.ProseMirror .is-empty:first-child::before {
  content: attr(data-placeholder);
  float: left;
  color: var(--color-text-muted);
  pointer-events: none;
  height: 0;
}
.collaboration-cursor__caret {
  border-left: 2px solid;
  border-right: 0; margin-left: -1px; margin-right: -1px;
  pointer-events: none; position: relative;
}
.collaboration-cursor__label {
  position: absolute;
  top: -1.4rem; left: -2px;
  font-size: 0.7rem;
  padding: 0.05rem 0.35rem;
  border-radius: 3px;
  color: #fff;
  white-space: nowrap;
}

/* ------- Modal ------- */
.modal-backdrop {
  position: fixed; inset: 0; background: rgba(0,0,0,0.5);
  display: flex; align-items: center; justify-content: center;
  z-index: 100; padding: 1rem;
}
.modal {
  background: var(--color-panel);
  border-radius: var(--radius-lg);
  box-shadow: var(--color-shadow);
  max-width: 560px;
  width: 100%;
  max-height: 90vh;
  display: flex; flex-direction: column;
}
.modal-header {
  padding: 1rem 1.2rem;
  border-bottom: 1px solid var(--color-border);
  display: flex; align-items: center; justify-content: space-between;
  gap: 0.5rem;
}
.modal-close {
  /* Ensure 2.5.8 Target Size (≥24×24 CSS px) for the icon-only close button. */
  min-width: 2.25rem;
  min-height: 2.25rem;
  justify-content: center;
  font-size: 1.2rem;
  line-height: 1;
}
.modal-title { margin: 0; font-size: 1.1rem; }
.modal-body { padding: 1rem 1.2rem; overflow-y: auto; }
.modal-footer {
  padding: 0.8rem 1.2rem;
  border-top: 1px solid var(--color-border);
  display: flex; gap: 0.5rem; justify-content: flex-end; flex-wrap: wrap;
}

.kbd {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 0.85em;
  background: var(--color-panel-alt);
  border: 1px solid var(--color-border-strong);
  border-radius: 4px;
  padding: 0.05rem 0.35rem;
}

.share-list { list-style: none; padding: 0; margin: 0; }
.share-list li {
  display: flex; align-items: center; justify-content: space-between; flex-wrap: wrap;
  padding: 0.4rem 0; border-bottom: 1px solid var(--color-border);
  gap: 0.5rem;
}
.share-list li:last-child { border-bottom: none; }
.share-list li > span:first-child {
  min-width: min(100%, 14rem);
  overflow-wrap: anywhere;
}
.share-person {
  display: grid;
  gap: 0.3rem;
}
.share-meta,
.share-actions,
.permission-toggle {
  display: flex;
  align-items: center;
  gap: 0.35rem;
  flex-wrap: wrap;
}
.share-actions {
  justify-content: flex-end;
}
.permission-toggle {
  min-height: 1.75rem;
}
.permission-toggle input {
  flex: 0 0 auto;
}

.code-blob {
  font-family: var(--font-mono);
  background: var(--color-panel-alt);
  border: 1px solid var(--color-border);
  padding: 0.6rem 0.8rem;
  border-radius: var(--radius);
  word-break: break-all;
  font-size: 0.9rem;
}
.backup-codes {
  display: grid; grid-template-columns: 1fr 1fr; gap: 0.3rem;
  font-family: var(--font-mono); font-size: 0.95rem;
}
.qr-img {
  width: 180px; height: 180px; image-rendering: pixelated;
  background: #fff; padding: 0.4rem; border-radius: 8px;
}

@media (max-width: 720px) {
  .editor-surface { padding: 1.5rem 1rem; }
  .doc-grid { grid-template-columns: 1fr; }
  .app-main { padding: 1rem 0.75rem 3rem; }
}

@media (prefers-reduced-motion: reduce) {
  * { transition: none !important; animation: none !important; }
}

.list-reset { list-style: none; padding: 0; margin: 0; }

.invite-banner {
  background: var(--color-accent-soft);
  border: 1px solid var(--color-accent);
  padding: 1rem;
  border-radius: var(--radius);
  margin-bottom: 1rem;
}

.tag {
  display: inline-block;
  font-size: 0.85rem;
  padding: 0.15rem 0.55rem;
  border-radius: 999px;
  background: var(--color-panel-alt);
  color: var(--color-text);
  border: 1px solid var(--color-border);
}
.tag.owner {
  background: var(--color-accent);
  color: var(--color-accent-fg);
  border-color: var(--color-accent);
}
.tag.viewer {
  background: var(--color-warning-bg);
  color: var(--color-text);
  border-color: var(--color-warning);
}

.spinner {
  width: 1rem; height: 1rem;
  border: 2px solid var(--color-border-strong);
  border-top-color: transparent;
  border-radius: 50%;
  animation: spin 0.8s linear infinite;
  display: inline-block;
}
@keyframes spin { to { transform: rotate(360deg); } }