/* ── Design tokens — raw RGB channels, consumed via rgb(var(--token)) ── */
:root {
  --color-primary:              68 114 210;
  --color-on-primary:           255 255 255;
  --color-primary-container:    221 232 254;
  --color-on-primary-container: 26 48 95;

  --color-surface:                255 255 255;
  --color-on-surface:             15 20 30;
  --color-on-surface-variant:     75 90 110;
  --color-surface-container-low:  248 250 252;
  --color-surface-container:      241 245 249;
  --color-surface-container-high: 227 233 241;

  --color-outline:         180 196 216;
  --color-outline-variant: 210 220 234;

  --color-error:           220 38 38;
  --color-error-container: 255 228 228;

  --color-shadow: 0 0 0;

  /* Layout constants — CSS-variable-driven so breakpoints only override the var */
  --sidebar-w: 280px;
  --appbar-h:  56px;
  --transition: 0.22s;
}

*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { height: 100%; }

body {
  font-family: 'DM Sans', sans-serif;
  background: rgb(var(--color-surface-container-low));
  color: rgb(var(--color-on-surface));
  height: 100%;
  display: flex;
  flex-direction: column;
  overflow: hidden;
}

/* ── App bar ── */
.app-bar {
  height: var(--appbar-h);
  background: rgb(var(--color-surface));
  border-bottom: 1px solid rgb(var(--color-outline-variant));
  display: flex;
  align-items: center;
  padding: 0 16px;
  gap: 10px;
  flex-shrink: 0;
  z-index: 20;
  box-shadow: 0 1px 0 rgb(var(--color-outline-variant));
}

/* Branded logo chip — anchors app identity without a full wordmark */
.app-bar__logo {
  width: 28px;
  height: 28px;
  background: rgb(var(--color-primary));
  border-radius: 7px;
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
  color: white;
}

.app-bar__title {
  font-size: 16px;
  font-weight: 600;
  color: rgb(var(--color-on-surface));
  flex: 1;
  letter-spacing: -0.01em;
}

/* ── Button system ── */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 8px 16px;
  border: none;
  border-radius: 8px;
  font-family: 'DM Sans', sans-serif;
  font-size: 14px;
  font-weight: 500;
  cursor: pointer;
  transition: opacity 0.15s, box-shadow 0.15s;
  white-space: nowrap;
}

.btn-primary {
  background: rgb(var(--color-primary));
  color: rgb(var(--color-on-primary));
}
.btn-primary:hover  { opacity: 0.88; box-shadow: 0 2px 8px rgba(var(--color-primary), 0.3); }
.btn-primary:active { opacity: 0.80; }

.btn-icon {
  background: transparent;
  border: none;
  width: 36px;
  height: 36px;
  border-radius: 8px;
  cursor: pointer;
  color: rgb(var(--color-on-surface-variant));
  display: inline-flex;
  align-items: center;
  justify-content: center;
  transition: background 0.15s, color 0.15s;
  flex-shrink: 0;
}
.btn-icon:hover { background: rgb(var(--color-surface-container)); color: rgb(var(--color-on-surface)); }

/* Red affordance signals destructive action before click */
.btn-icon.danger:hover {
  background: rgb(var(--color-error-container));
  color: rgb(var(--color-error));
}

/* ── Layout shell ── */
.layout {
  display: flex;
  flex: 1;
  overflow: hidden;
  position: relative;
}

/* ── Mobile overlay — dims content behind open sidebar ── */
.sidebar-overlay {
  display: none;
  position: fixed;
  top: var(--appbar-h);
  inset-inline: 0;
  bottom: 0;
  background: rgba(var(--color-shadow), 0.28);
  z-index: 9;
  opacity: 0;
  transition: opacity var(--transition);
  pointer-events: none; /* opacity:0 does NOT disable pointer events — without this the transparent overlay blocks all editor clicks on mobile */
}
.sidebar-overlay.active { opacity: 1; pointer-events: auto; }

/* ── Sidebar ── */
.sidebar {
  width: var(--sidebar-w);
  flex-shrink: 0;
  background: rgb(var(--color-surface));
  border-right: 1px solid rgb(var(--color-outline-variant));
  display: flex;
  flex-direction: column;
  overflow: hidden;
}

.sidebar__header {
  padding: 14px 12px 12px;
  border-bottom: 1px solid rgb(var(--color-outline-variant));
  display: flex;
  flex-direction: column;
  gap: 10px;
  flex-shrink: 0;
}

.sidebar__header-row {
  display: flex;
  align-items: center;
}

.sidebar__section-label {
  font-size: 11px;
  font-weight: 600;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: rgb(var(--color-on-surface-variant));
  flex: 1;
}

/* Pill badge makes note count feel like a status chip, not raw copy */
.sidebar__count-badge {
  font-size: 11px;
  font-weight: 500;
  color: rgb(var(--color-on-surface-variant));
  background: rgb(var(--color-surface-container));
  padding: 2px 8px;
  border-radius: 10px;
}

/* ── Search ── */
.search-wrapper { position: relative; }

.search-icon {
  position: absolute;
  left: 10px;
  top: 50%;
  transform: translateY(-50%);
  color: rgb(var(--color-on-surface-variant));
  pointer-events: none;
  opacity: 0.55;
}

.search-input {
  width: 100%;
  padding: 8px 12px 8px 34px;
  background: rgb(var(--color-surface-container-low));
  border: 1.5px solid rgb(var(--color-outline-variant));
  border-radius: 8px;
  font-family: 'DM Sans', sans-serif;
  font-size: 13.5px;
  color: rgb(var(--color-on-surface));
  outline: none;
  transition: border-color 0.15s, background 0.15s, box-shadow 0.15s;
}
.search-input::placeholder { color: rgb(var(--color-on-surface-variant)); opacity: 0.5; }
.search-input:focus {
  border-color: rgb(var(--color-primary));
  background: rgb(var(--color-surface));
  /* Soft glow ring — consistent with input focus convention throughout the app */
  box-shadow: 0 0 0 3px rgba(var(--color-primary), 0.1);
}

/* ── Notes list ── */
.notes-list {
  flex: 1;
  overflow-y: auto;
  padding: 6px 8px 8px;
}

/* Thin scrollbar — doesn't compete visually with note content */
.notes-list::-webkit-scrollbar { width: 3px; }
.notes-list::-webkit-scrollbar-track { background: transparent; }
.notes-list::-webkit-scrollbar-thumb {
  background: rgb(var(--color-outline-variant));
  border-radius: 2px;
}

.note-item {
  padding: 11px 12px;
  border-radius: 8px;
  cursor: pointer;
  transition: background 0.12s;
  border: 1px solid transparent;
  margin-bottom: 2px;
}
.note-item:hover { background: rgb(var(--color-surface-container-low)); }

/* Primary-container communicates selection without heavy visual weight */
.note-item.active {
  background: rgb(var(--color-primary-container));
  border-color: rgba(var(--color-primary), 0.18);
}

.note-item__title {
  font-size: 13.5px;
  font-weight: 500;
  color: rgb(var(--color-on-surface));
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
  margin-bottom: 3px;
  line-height: 1.4;
}
.note-item.active .note-item__title { color: rgb(var(--color-on-primary-container)); }

.note-item__preview {
  font-size: 12.5px;
  color: rgb(var(--color-on-surface-variant));
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
  margin-bottom: 5px;
  opacity: 0.8;
  line-height: 1.4;
}

.note-item__date {
  font-size: 11px;
  color: rgb(var(--color-on-surface-variant));
  opacity: 0.6;
}

/* ── Empty state ── */
.empty-state {
  display: flex;
  flex-direction: column;
  align-items: center;
  padding: 48px 20px 32px;
  gap: 4px;
  color: rgb(var(--color-on-surface-variant));
  text-align: center;
}
.empty-state__icon { opacity: 0.28; margin-bottom: 8px; }
.empty-state__label { font-size: 13.5px; font-weight: 500; }
.empty-state__sublabel { font-size: 12px; opacity: 0.65; margin-top: 3px; }

/* ── Editor area ── */
.editor-area {
  flex: 1;
  min-width: 0; /* prevent flex child from overflowing on narrow viewports */
  display: flex;
  flex-direction: column;
  overflow: hidden;
  background: rgb(var(--color-surface));
}

.editor__toolbar {
  display: flex;
  align-items: center;
  padding: 0 16px;
  height: 48px;
  border-bottom: 1px solid rgb(var(--color-outline-variant));
  gap: 8px;
  flex-shrink: 0;
}

.editor__meta {
  flex: 1;
  min-width: 0;
  display: flex;
  flex-direction: column;
  justify-content: center;
  gap: 1px;
}

.editor__date {
  font-size: 12px;
  color: rgb(var(--color-on-surface-variant));
  opacity: 0.7;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

/* Fades in/out below the date — doesn't shift layout when hidden */
.editor__save-status {
  font-size: 11px;
  font-weight: 500;
  color: rgb(var(--color-primary));
  height: 14px;
  opacity: 1;
  transition: opacity 0.4s;
}
.editor__save-status.hidden { opacity: 0; }

/* Scrollable writing surface — separate from the sticky toolbar and stats bar */
.editor__scroll {
  flex: 1;
  overflow-y: auto;
  display: flex;
  flex-direction: column;
}
.editor__scroll::-webkit-scrollbar { width: 4px; }
.editor__scroll::-webkit-scrollbar-track { background: transparent; }
.editor__scroll::-webkit-scrollbar-thumb {
  background: rgb(var(--color-outline-variant));
  border-radius: 2px;
}

/* Max-width constrains line length for comfortable reading at ~70 chars */
.editor__content {
  padding: 32px 48px 48px;
  max-width: 740px;
  width: 100%;
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  flex: 1;
}

.editor__title-input {
  font-family: 'DM Sans', sans-serif;
  font-size: 24px;
  font-weight: 600;
  color: rgb(var(--color-on-surface));
  border: none;
  outline: none;
  background: transparent;
  width: 100%;
  padding: 0;
  resize: none;
  overflow: hidden;
  line-height: 1.3;
  letter-spacing: -0.02em;
  margin-bottom: 2px;
}
.editor__title-input::placeholder { color: rgb(var(--color-on-surface-variant)); opacity: 0.28; }

/* Horizontal rule separates title from body — improves visual hierarchy without a border on inputs */
.editor__divider {
  height: 1px;
  background: rgb(var(--color-outline-variant));
  margin: 14px 0 16px;
}

.editor__body-input {
  font-family: 'DM Sans', sans-serif;
  font-size: 15px;
  line-height: 1.8;
  color: rgb(var(--color-on-surface));
  border: none;
  outline: none;
  background: transparent;
  width: 100%;
  flex: 1;
  resize: none;
  min-height: 240px;
  padding: 0;
}
.editor__body-input::placeholder { color: rgb(var(--color-on-surface-variant)); opacity: 0.3; }

/* Stats footer — lightweight reference, not a distraction */
.editor__footer {
  border-top: 1px solid rgb(var(--color-outline-variant));
  padding: 6px 48px;
  display: flex;
  gap: 16px;
  flex-shrink: 0;
  background: rgb(var(--color-surface));
}

.editor__stat {
  font-size: 11.5px;
  color: rgb(var(--color-on-surface-variant));
  opacity: 0.55;
}

/* ── No-selection placeholder ── */
.no-note-selected {
  flex: 1;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 8px;
  color: rgb(var(--color-on-surface-variant));
  background: rgb(var(--color-surface-container-low));
  user-select: none;
  padding: 32px;
  text-align: center;
}
.no-note-selected__icon { opacity: 0.18; margin-bottom: 4px; }
.no-note-selected__text { font-size: 16px; font-weight: 500; opacity: 0.6; }
.no-note-selected__hint { font-size: 13px; opacity: 0.4; }
.no-note-selected__cta  { margin-top: 12px; }

/* ── Mobile FAB — floats above content, replaces header button ── */
.fab {
  display: none;
  position: fixed;
  bottom: 24px;
  right: 20px;
  width: 54px;
  height: 54px;
  border-radius: 16px;
  background: rgb(var(--color-primary));
  color: white;
  border: none;
  cursor: pointer;
  align-items: center;
  justify-content: center;
  /* Elevated shadow to float above the writing surface */
  box-shadow: 0 4px 16px rgba(var(--color-primary), 0.38);
  z-index: 25;
  transition: transform 0.15s, box-shadow 0.15s;
}
.fab:hover  { transform: scale(1.04); box-shadow: 0 6px 20px rgba(var(--color-primary), 0.44); }
.fab:active { transform: scale(0.96); }

/* ── Responsive breakpoints ── */

/* Tablet: narrower sidebar via variable override — no other layout change needed */
@media (max-width: 900px) and (min-width: 640px) {
  :root { --sidebar-w: 240px; }
  .editor__content { padding: 28px 36px 40px; }
  .editor__footer  { padding: 6px 36px; }
}

/* Mobile: sidebar becomes a fixed slide-in overlay */
@media (max-width: 639px) {
  .sidebar {
    position: fixed;
    top: var(--appbar-h);
    left: 0;
    bottom: 0;
    width: min(300px, 82vw);
    z-index: 10;
    /* Starts off-screen; `.open` slides it in */
    transform: translateX(-100%);
    transition: transform var(--transition) ease;
    box-shadow: 4px 0 24px rgba(var(--color-shadow), 0.1);
  }

  .sidebar.open { transform: translateX(0); }

  /* Overlay backdrop is only meaningful on mobile */
  .sidebar-overlay { display: block; }

  /* FAB replaces header New Note button on mobile */
  .fab { display: inline-flex; }
  .app-bar__new-btn { display: none !important; }

  /* Extra bottom padding clears the FAB */
  .editor__content { padding: 20px 20px 80px; }
  .editor__footer  { padding: 6px 20px; }
}

/* Very small phones */
@media (max-width: 380px) {
  .app-bar        { padding: 0 12px; gap: 8px; }
  .editor__content { padding: 16px 16px 80px; }
  .editor__footer  { padding: 6px 16px; }
}

/* ── Default visibility states ── */
.sidebar-toggle-btn { display: none; }

@media (max-width: 639px) {
  .sidebar-toggle-btn { display: inline-flex; }
}

/* ── Lucide SVG sizing — per-context overrides ── */
.app-bar__logo  svg                  { width: 15px; height: 15px; }
.btn-primary    svg                  { width: 16px; height: 16px; }
.search-icon, .search-icon svg       { width: 15px; height: 15px; }
.no-note-selected__icon svg          { width: 56px; height: 56px; display: block; }
.empty-state__icon svg               { width: 32px; height: 32px; display: block; }
.fab svg                             { width: 24px; height: 24px; }

/* Keyboard focus ring — visible for accessibility, suppressed on mouse */
:focus-visible {
  outline: 2px solid rgb(var(--color-primary));
  outline-offset: 2px;
}

/* ── Delete confirmation modal ── */

/* Fixed overlay — z-index 50 clears the sidebar (10), overlay (9), and FAB (25).
   opacity+pointer-events toggle instead of display:none so the CSS transition fires. */
.modal-backdrop {
  position: fixed;
  inset: 0;
  background: rgba(var(--color-shadow), 0.38);
  z-index: 50;
  display: flex;
  align-items: center;
  justify-content: center;
  backdrop-filter: blur(3px);
  -webkit-backdrop-filter: blur(3px);
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.18s ease;
}

.modal-backdrop.open {
  opacity: 1;
  pointer-events: auto;
}

.modal-backdrop.open .modal {
  animation: modal-slide-in 0.22s cubic-bezier(0.34, 1.2, 0.64, 1) forwards;
}

@keyframes modal-slide-in {
  from { opacity: 0; transform: scale(0.92) translateY(10px); }
  to   { opacity: 1; transform: scale(1)    translateY(0); }
}

.modal {
  background: rgb(var(--color-surface));
  border-radius: 16px;
  padding: 28px 28px 24px;
  width: min(400px, calc(100vw - 40px));
  box-shadow:
    0 8px 40px rgba(var(--color-shadow), 0.14),
    0 2px 8px  rgba(var(--color-shadow), 0.08);
  display: flex;
  flex-direction: column;
  align-items: center;
  text-align: center;
  gap: 12px;
}

/* Red icon chip mirrors the trash button's danger hover — primes the user for severity before they read the text */
.modal__icon {
  width: 48px;
  height: 48px;
  background: rgb(var(--color-error-container));
  border-radius: 12px;
  display: flex;
  align-items: center;
  justify-content: center;
  color: rgb(var(--color-error));
  margin-bottom: 4px;
  flex-shrink: 0;
}
.modal__icon svg { width: 22px; height: 22px; }

.modal__title {
  font-size: 17px;
  font-weight: 600;
  color: rgb(var(--color-on-surface));
  letter-spacing: -0.01em;
}

.modal__body {
  font-size: 13.5px;
  color: rgb(var(--color-on-surface-variant));
  line-height: 1.6;
  max-width: 280px;
}

.modal__actions {
  display: flex;
  gap: 10px;
  margin-top: 8px;
  width: 100%;
}

/* Ghost variant — understated so visual weight draws the eye to the danger button */
.btn-ghost {
  flex: 1;
  background: transparent;
  color: rgb(var(--color-on-surface-variant));
  border: 1.5px solid rgb(var(--color-outline));
}
.btn-ghost:hover {
  background: rgb(var(--color-surface-container));
  color: rgb(var(--color-on-surface));
  border-color: rgb(var(--color-outline-variant));
}
.btn-ghost:active { opacity: 0.75; }

/* Danger variant — same error palette as the trash icon hover, intentional visual continuity */
.btn-danger {
  flex: 1;
  background: rgb(var(--color-error));
  color: rgb(var(--color-on-primary));
}
.btn-danger:hover  { opacity: 0.88; box-shadow: 0 2px 8px rgba(var(--color-error), 0.35); }
.btn-danger:active { opacity: 0.80; }