/* ---------- Theme ---------- */

:root {
  --bg-0: #0e0f13;
  --bg-1: #16181f;
  --bg-2: #1c1f28;
  --bg-3: #262a36;
  --border: #333846;
  --text: #e8e6e0;
  --text-dim: #9198a8;
  --accent: #6ee7b7;
  --accent-2: #f6c177;
  --danger: #f28b82;
  --canvas-bg: #0b0c10;
  --grid-line: #262a36;
  --ink-default: #e8e6e0;
  --checker-a: #15161b;
  --checker-b: transparent;
  --hover-cell: rgba(255, 255, 255, 0.06);
  color-scheme: dark;
}

/* Follow the OS preference when the user hasn't explicitly chosen a theme */
@media (prefers-color-scheme: light) {
  :root {
    --bg-0: #f3f4f7;
    --bg-1: #ffffff;
    --bg-2: #f3f4f7;
    --bg-3: #e7e9ef;
    --border: #d7dae1;
    --text: #1b1e27;
    --text-dim: #6b7280;
    --accent: #059669;
    --accent-2: #b45309;
    --danger: #dc2626;
    --canvas-bg: #ffffff;
    --grid-line: #e5e7eb;
    --ink-default: #1b1e27;
    --checker-a: #eceef2;
    --checker-b: transparent;
    --hover-cell: rgba(0, 0, 0, 0.05);
    color-scheme: light;
  }
}

/* Explicit user choice (toggle button) always wins over the OS preference */
:root[data-theme="dark"] {
  --bg-0: #0e0f13;
  --bg-1: #16181f;
  --bg-2: #1c1f28;
  --bg-3: #262a36;
  --border: #333846;
  --text: #e8e6e0;
  --text-dim: #9198a8;
  --accent: #6ee7b7;
  --accent-2: #f6c177;
  --danger: #f28b82;
  --canvas-bg: #0b0c10;
  --grid-line: #262a36;
  --ink-default: #e8e6e0;
  --checker-a: #15161b;
  --checker-b: transparent;
  --hover-cell: rgba(255, 255, 255, 0.06);
  color-scheme: dark;
}
:root[data-theme="light"] {
  --bg-0: #f3f4f7;
  --bg-1: #ffffff;
  --bg-2: #f3f4f7;
  --bg-3: #e7e9ef;
  --border: #d7dae1;
  --text: #1b1e27;
  --text-dim: #6b7280;
  --accent: #059669;
  --accent-2: #b45309;
  --danger: #dc2626;
  --canvas-bg: #ffffff;
  --grid-line: #e5e7eb;
  --ink-default: #1b1e27;
  --checker-a: #eceef2;
  --checker-b: transparent;
  --hover-cell: rgba(0, 0, 0, 0.05);
  color-scheme: light;
}

/* Sun/moon icon swap: show moon (switch-to-dark) in light mode, sun (switch-to-light) in dark mode */
#theme-icon-light { display: none; }
:root[data-theme="light"] #theme-icon-dark { display: none; }
:root[data-theme="light"] #theme-icon-light { display: block; }
@media (prefers-color-scheme: light) {
  :root:not([data-theme="dark"]) #theme-icon-dark { display: none; }
  :root:not([data-theme="dark"]) #theme-icon-light { display: block; }
}

* { box-sizing: border-box; -webkit-tap-highlight-color: transparent; }

html, body {
  height: 100%;
  margin: 0;
  background: var(--bg-0);
  color: var(--text);
  font-family: ui-monospace, "SF Mono", "JetBrains Mono", "Fira Code", Consolas, Menlo, monospace;
  font-size: 13px;
  overflow: hidden;
}

#app {
  display: flex;
  flex-direction: column;
  height: 100%;
}

.icon {
  width: 16px;
  height: 16px;
  flex-shrink: 0;
  vertical-align: -3px;
}
.tool-btn .icon { width: 18px; height: 18px; vertical-align: -4px; }
.layer-btn .icon { width: 14px; height: 14px; margin-right: 5px; }
.icon-chevron { width: 12px; height: 12px; margin-left: -2px; opacity: 0.7; }
button .icon + text { margin-left: 4px; }

/* ---------- Toolbar ---------- */

#toolbar {
  display: flex;
  align-items: center;
  gap: 14px;
  padding: 8px 14px;
  background: var(--bg-1);
  border-bottom: 1px solid var(--border);
  flex-wrap: wrap;
}

.brand {
  font-weight: 700;
  font-size: 16px;
  letter-spacing: 0.5px;
  color: var(--accent);
  margin-right: 6px;
}
.brand-dot {
  color: var(--accent-2);
  display: inline-block;
  width: 1ch;
  text-align: center;
}

.toolbar-group {
  display: flex;
  align-items: center;
  gap: 4px;
  padding: 3px 6px;
  background: var(--bg-2);
  border: 1px solid var(--border);
  border-radius: 8px;
}

.theme-controls { margin-left: auto; }

button {
  background: transparent;
  border: 1px solid transparent;
  color: var(--text);
  padding: 5px 8px;
  border-radius: 6px;
  cursor: pointer;
  font-family: inherit;
  font-size: 13px;
  line-height: 1;
  display: inline-flex;
  align-items: center;
  gap: 5px;
  touch-action: manipulation;
}

/* Off-canvas sidebar toggle — only shown on narrow viewports (see media
   query below); irrelevant on desktop where the sidebar is always visible. */
#sidebar-toggle-btn { display: none; }
button:hover { background: var(--bg-3); }
button:active { transform: translateY(1px); }
button.active {
  background: var(--accent);
  color: var(--bg-0);
  border-color: var(--accent);
}
button:disabled { opacity: 0.4; cursor: default; }
button:disabled:hover { background: transparent; }

.zoom-controls span { min-width: 42px; text-align: center; color: var(--text-dim); }

.file-label {
  background: transparent;
  padding: 5px 8px;
  border-radius: 6px;
  cursor: pointer;
  display: inline-flex;
  align-items: center;
  gap: 5px;
}
.file-label:hover { background: var(--bg-3); }

.dropdown { position: relative; }
.dropdown-menu {
  display: none;
  position: absolute;
  top: 110%;
  left: 0;
  background: var(--bg-2);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 4px;
  min-width: 170px;
  z-index: 50;
  flex-direction: column;
  box-shadow: 0 8px 24px rgba(0,0,0,0.4);
}
.dropdown.open .dropdown-menu { display: flex; }
.dropdown-menu button { text-align: left; width: 100%; }

/* ---------- Main layout ---------- */

#main {
  flex: 1;
  display: flex;
  min-height: 0;
}

#sidebar {
  width: 260px;
  flex-shrink: 0;
  background: var(--bg-1);
  border-right: 1px solid var(--border);
  overflow-y: auto;
  padding: 10px;
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.panel {
  background: var(--bg-2);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 10px;
}
.panel h3 {
  margin: 0 0 8px 0;
  font-size: 11px;
  text-transform: uppercase;
  letter-spacing: 1px;
  color: var(--text-dim);
}

/* ---------- Brush panel ---------- */

.brush-row { display: flex; align-items: center; gap: 8px; margin-bottom: 12px; }

.line-mode-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 8px;
  margin-bottom: 12px;
  flex-wrap: wrap;
}
.line-mode-row .checkbox-row {
  display: flex;
  align-items: center;
  gap: 6px;
  font-size: 12px;
  color: var(--text);
}
#line-style-select {
  background: var(--bg-3);
  border: 1px solid var(--border);
  color: var(--text);
  border-radius: 6px;
  padding: 4px 6px;
  font-family: inherit;
  font-size: 11px;
}
#line-style-select:disabled { opacity: 0.4; cursor: default; }

/* Collapsed by default — Ink and Canvas background are settings you dip
   into occasionally, not something that needs to stay on screen. */
.collapsible summary {
  cursor: pointer;
  list-style: none;
  display: flex;
  align-items: center;
  gap: 6px;
  font-size: 11px;
  text-transform: uppercase;
  letter-spacing: 1px;
  color: var(--text-dim);
  padding: 4px 0;
  user-select: none;
}
.collapsible summary::-webkit-details-marker { display: none; }
.collapsible summary::marker { content: ""; }
.collapse-icon { width: 12px; height: 12px; flex-shrink: 0; margin-left: auto; }
.collapse-icon-minus { display: none; }
.collapsible[open] .collapse-icon-plus { display: none; }
.collapsible[open] .collapse-icon-minus { display: block; }
.collapsible-content { padding-top: 8px; }

.section-label {
  font-size: 10px;
  text-transform: uppercase;
  letter-spacing: 0.6px;
  color: var(--text-dim);
  margin-bottom: 6px;
}

.inline-custom-row {
  margin-top: 8px;
  margin-bottom: 14px;
  padding-top: 0;
  border-top: none;
}

/* Same 7-column grid as .swatch-grid, so the swatch is pixel-identical in
   size to the ROYGBIV ones below it — the label just spans the rest. */
.default-ink-row {
  display: grid;
  grid-template-columns: repeat(7, 1fr);
  gap: 5px;
  align-items: center;
  margin-bottom: 8px;
}
.default-ink-swatch {
  background: var(--ink-default);
}
.default-ink-row .color-label {
  grid-column: 2 / -1;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

#brush-preview {
  width: 38px;
  height: 38px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--canvas-bg);
  border: 1px solid var(--border);
  border-radius: 6px;
  font-size: 18px;
  color: var(--ink-default);
}
#custom-char {
  flex: 1;
  min-width: 0;
  background: var(--bg-3);
  border: 1px solid var(--border);
  color: var(--text);
  border-radius: 6px;
  padding: 6px;
  text-align: center;
}

.color-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 6px 8px;
  border-radius: 8px;
  margin-bottom: 6px;
  border: 1px solid transparent;
}
.color-row.active-color-row {
  background: var(--bg-3);
  border-color: var(--accent);
}
.color-label { font-size: 12px; color: var(--text-dim); }
.color-swatch {
  width: 30px;
  height: 30px;
  border-radius: 7px;
  border: 1px solid var(--border);
  padding: 0;
  cursor: pointer;
  display: block;
}
.color-swatch.is-empty {
  background-image:
    linear-gradient(45deg, var(--border) 25%, transparent 25%),
    linear-gradient(-45deg, var(--border) 25%, transparent 25%),
    linear-gradient(45deg, transparent 75%, var(--border) 75%),
    linear-gradient(-45deg, transparent 75%, var(--border) 75%);
  background-size: 10px 10px;
  background-position: 0 0, 0 5px, 5px -5px, -5px 0px;
  background-color: var(--bg-2);
}

/* ---------- Color popover ---------- */

.color-popover {
  position: fixed;
  z-index: 200;
  background: var(--bg-2);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 10px;
  width: 202px;
  box-shadow: 0 12px 32px rgba(0,0,0,0.4);
}
.popover-label {
  font-size: 10px;
  text-transform: uppercase;
  letter-spacing: 0.6px;
  color: var(--text-dim);
  margin: 6px 0 5px;
}
.popover-label:first-child { margin-top: 0; }
.swatch-grid {
  display: grid;
  grid-template-columns: repeat(7, 1fr);
  gap: 5px;
}
.mini-swatch {
  width: 100%;
  aspect-ratio: 1;
  border-radius: 6px;
  border: 1px solid rgba(128,128,128,0.35);
  cursor: pointer;
  padding: 0;
  display: block;
}
.mini-swatch:hover { transform: scale(1.15); }
.mini-swatch.selected { outline: 2px solid var(--accent); outline-offset: 1px; }
.mini-swatch.none-swatch {
  background-image:
    linear-gradient(45deg, var(--border) 25%, transparent 25%),
    linear-gradient(-45deg, var(--border) 25%, transparent 25%),
    linear-gradient(45deg, transparent 75%, var(--border) 75%),
    linear-gradient(-45deg, transparent 75%, var(--border) 75%);
  background-size: 8px 8px;
  background-position: 0 0, 0 4px, 4px -4px, -4px 0px;
  background-color: var(--bg-2);
}
.custom-color-row {
  display: flex;
  align-items: center;
  gap: 8px;
  margin-top: 8px;
  padding-top: 8px;
  border-top: 1px solid var(--border);
}
.custom-color-row input[type="color"] {
  width: 30px;
  height: 30px;
  padding: 0;
  border: 1px solid var(--border);
  border-radius: 6px;
  background: transparent;
  cursor: pointer;
}

.grid-controls-row {
  display: flex;
  align-items: center;
  gap: 8px;
  margin-bottom: 6px;
  flex-wrap: wrap;
}
.grid-controls-row label {
  display: flex;
  align-items: center;
  gap: 4px;
  color: var(--text-dim);
  font-size: 12px;
}
.grid-controls-row input[type="number"] {
  width: 56px;
  background: var(--bg-3);
  border: 1px solid var(--border);
  color: var(--text);
  border-radius: 6px;
  padding: 4px 6px;
}
.checkbox-row { cursor: pointer; }

/* ---------- Reference layer panel ---------- */

.reference-row {
  display: flex;
  align-items: center;
  gap: 6px;
  margin-bottom: 8px;
}
.reference-row .file-label { flex: 1; justify-content: center; }
.reference-opacity-row input[type="range"] {
  flex: 1;
  min-width: 0;
  accent-color: var(--accent);
}
.reference-opacity-row #reference-opacity-label {
  min-width: 34px;
  text-align: right;
  color: var(--text-dim);
  font-size: 12px;
}
#reference-fit {
  flex: 1;
  background: var(--bg-3);
  border: 1px solid var(--border);
  color: var(--text);
  border-radius: 6px;
  padding: 4px 6px;
  font-family: inherit;
  font-size: 12px;
}
#reference-fit:disabled { opacity: 0.4; cursor: default; }

/* eye / eye-off icon swap, same pattern as the light/dark theme icons.
   The "visible" highlight itself reuses the existing button.active rule. */
.ref-icon-off { display: none; }
.ref-toggle-btn.ref-hidden .ref-icon-on { display: none; }
.ref-toggle-btn.ref-hidden .ref-icon-off { display: block; }

.palette-panel { flex: 1; overflow: hidden; display: flex; flex-direction: column; }
#palette-groups { overflow-y: auto; flex: 1; }

.palette-group { margin-bottom: 10px; }
.palette-group-title {
  font-size: 11px;
  color: var(--accent-2);
  margin-bottom: 5px;
  cursor: pointer;
  user-select: none;
}
.palette-chars {
  display: grid;
  grid-template-columns: repeat(7, 1fr);
  gap: 4px;
}
.char-btn {
  background: var(--bg-3);
  border: 1px solid var(--border);
  border-radius: 5px;
  padding: 4px 0;
  font-size: 14px;
  display: flex;
  align-items: center;
  justify-content: center;
  min-width: 0;
}
.char-btn:hover { border-color: var(--accent); }
.char-btn.active { background: var(--accent); color: var(--bg-0); border-color: var(--accent); }

/* ---------- Canvas ---------- */

#canvas-wrap {
  flex: 1;
  overflow: auto;
  background:
    linear-gradient(45deg, var(--checker-a) 25%, transparent 25%),
    linear-gradient(-45deg, var(--checker-a) 25%, transparent 25%),
    linear-gradient(45deg, transparent 75%, var(--checker-a) 75%),
    linear-gradient(-45deg, transparent 75%, var(--checker-a) 75%);
  background-size: 20px 20px;
  background-position: 0 0, 0 10px, 10px -10px, -10px 0px;
  background-color: var(--bg-0);
  display: flex;
  align-items: flex-start;
  justify-content: flex-start;
  padding: 24px;
}

#grid-canvas {
  background: var(--canvas-bg);
  box-shadow: 0 0 0 1px var(--border), 0 4px 12px rgba(0,0,0,0.18);
  cursor: crosshair;
  image-rendering: pixelated;
  /* Drawing owns all touch input on the canvas — without this, a finger
     drag pans/zooms the page instead of drawing, and the stroke never
     reaches the pointer handlers. */
  touch-action: none;
}

/* Backdrop behind the off-canvas sidebar drawer on mobile — inert and
   invisible on desktop, where the sidebar never leaves the layout flow. */
#sidebar-backdrop {
  display: none;
}

/* ---------- Status bar ---------- */

#statusbar {
  display: flex;
  gap: 18px;
  padding: 6px 14px;
  background: var(--bg-1);
  border-top: 1px solid var(--border);
  color: var(--text-dim);
  font-size: 12px;
  flex-wrap: wrap;
}
.footer-credit {
  margin-left: auto;
}
.footer-credit a {
  color: var(--text-dim);
  text-decoration: none;
}
.footer-credit a:hover {
  color: var(--accent);
  text-decoration: underline;
}

/* ---------- Text tool floating input ---------- */

#text-tool-input {
  position: fixed;
  z-index: 100;
  background: var(--bg-2);
  border: 1px solid var(--accent);
  border-radius: 6px;
  padding: 4px;
}
#text-tool-input.hidden { display: none; }
#text-tool-field {
  background: var(--bg-3);
  border: 1px solid var(--border);
  color: var(--text);
  border-radius: 4px;
  padding: 6px 8px;
  font-family: inherit;
  min-width: 240px;
}

/* ---------- Tooltips ---------- */
/* Custom tooltips layered on top of the native `title` attribute — some
   embedded/automated browser contexts never render the OS-level tooltip
   at all, so the app can't rely on native title tooltips alone. Reads
   the same `title` text via attr(), so no HTML/JS duplication needed. */
[title] {
  position: relative;
}
[title]::after {
  content: attr(title);
  position: absolute;
  top: calc(100% + 7px);
  left: 50%;
  transform: translateX(-50%);
  width: max-content;
  max-width: 220px;
  padding: 5px 9px;
  background: var(--bg-3);
  color: var(--text);
  border: 1px solid var(--border);
  border-radius: 6px;
  font-size: 11px;
  line-height: 1.35;
  text-align: center;
  white-space: normal;
  pointer-events: none;
  z-index: 999;
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.35);
  opacity: 0;
  visibility: hidden;
  transition: opacity 0.12s ease, visibility 0s linear 0.3s;
}
[title]:hover::after,
[title]:focus-visible::after {
  opacity: 1;
  visibility: visible;
  transition-delay: 0.3s;
}

/* scrollbars */
::-webkit-scrollbar { width: 10px; height: 10px; }
::-webkit-scrollbar-track { background: var(--bg-1); }
::-webkit-scrollbar-thumb { background: var(--bg-3); border-radius: 6px; }
::-webkit-scrollbar-thumb:hover { background: var(--border); }

/* ---------- Mobile layout ---------- */
/* The sidebar becomes an off-canvas drawer (toggled by #sidebar-toggle-btn)
   so the canvas gets the full width, the toolbar becomes a single
   horizontally-scrolling row so it doesn't eat vertical space better spent
   on the drawing surface, and every tap target grows a bit. */
@media (max-width: 768px) {
  #sidebar-toggle-btn { display: inline-flex; }

  #toolbar {
    flex-wrap: nowrap;
    overflow-x: auto;
    -webkit-overflow-scrolling: touch;
    scrollbar-width: none;
    gap: 8px;
    padding: 8px 10px;
  }
  #toolbar::-webkit-scrollbar { display: none; }
  .toolbar-group { flex-shrink: 0; }
  .theme-controls, .reference-controls { margin-left: 0; }
  .brand { margin-right: 2px; }

  button, .file-label { padding: 8px 10px; }
  .icon { width: 18px; height: 18px; }
  .tool-btn .icon { width: 20px; height: 20px; }

  #main { position: relative; }

  #sidebar {
    position: fixed;
    top: 0;
    left: 0;
    height: 100%;
    width: min(86vw, 320px);
    z-index: 300;
    transform: translateX(-100%);
    transition: transform 0.22s ease;
    box-shadow: 6px 0 28px rgba(0, 0, 0, 0.4);
  }
  #sidebar.open { transform: translateX(0); }

  #sidebar-backdrop {
    display: block;
    position: fixed;
    inset: 0;
    background: rgba(0, 0, 0, 0.45);
    z-index: 250;
    opacity: 0;
    visibility: hidden;
    transition: opacity 0.2s ease;
  }
  #sidebar-backdrop.visible { opacity: 1; visibility: visible; }

  #canvas-wrap { padding: 12px; }

  #statusbar { font-size: 11px; gap: 10px; padding: 6px 10px; }

  /* Native title tooltips are a hover affordance — meaningless (and prone
     to getting stuck open after a tap) on a touch screen. */
  [title]::after { display: none !important; }
}