/* EEG Electrode Explorer — main stylesheet */
:root {
  --bg: #f6f4ef;
  --bg-2: #efece5;
  --ink: #17181a;
  --ink-2: #3a3d42;
  --muted: #8b8e94;
  --ink-3: #b5b8bd;
  --surface: #fbfaf6;
  --line: #dedbd2;
  --line-2: #e8e5dc;
  --accent: oklch(0.55 0.15 240);
  --accent-soft: oklch(0.92 0.04 240);
  --warn: oklch(0.62 0.16 40);
  --frontal:   oklch(0.60 0.14 265);
  --central:   oklch(0.62 0.14 150);
  --parietal:  oklch(0.62 0.15 85);
  --occipital: oklch(0.58 0.15 25);
  --reference: oklch(0.50 0.02 270);
  --egi: oklch(0.55 0.15 300);
  --other: oklch(0.55 0.02 270);
}

* { box-sizing: border-box; }
html, body { margin: 0; padding: 0; height: 100%; }
body {
  font-family: "IBM Plex Sans", system-ui, -apple-system, sans-serif;
  color: var(--ink);
  background: var(--bg);
  font-size: 13px;
  line-height: 1.45;
  overflow: hidden;
  -webkit-font-smoothing: antialiased;
}

/* Layout */
.app {
  display: grid;
  grid-template-columns: 260px 1fr 300px;
  grid-template-rows: 48px 1fr 220px;
  grid-template-areas:
    "header header header"
    "left   stage  right"
    "left   tsv    right";
  height: 100vh;
  width: 100vw;
  gap: 0;
}

/* Header */
.header {
  grid-area: header;
  display: flex;
  align-items: center;
  padding: 0 20px;
  border-bottom: 1px solid var(--line);
  gap: 16px;
  background: var(--bg);
  z-index: 5;
}
.brand { display: flex; align-items: baseline; gap: 10px; }
.brand-mark {
  width: 18px; height: 18px; border-radius: 50%;
  background: radial-gradient(circle at 35% 35%, #fff 0, var(--accent) 70%);
  box-shadow: 0 0 0 1px rgba(0,0,0,0.08) inset;
  transform: translateY(3px);
}
.brand-title {
  font-family: "IBM Plex Mono", monospace;
  font-size: 12px;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--ink);
}
.brand-sub {
  font-family: "IBM Plex Mono", monospace;
  font-size: 11px;
  color: var(--muted);
  letter-spacing: 0.05em;
}
.header-right {
  margin-left: auto;
  display: flex;
  gap: 6px;
  align-items: center;
  font-family: "IBM Plex Mono", monospace;
  font-size: 11px;
  color: var(--muted);
}
.pill {
  padding: 3px 9px;
  border: 1px solid var(--line);
  border-radius: 999px;
  font-family: "IBM Plex Mono", monospace;
  font-size: 10.5px;
  color: var(--ink-2);
  letter-spacing: 0.04em;
  background: var(--bg);
}

/* Rails */
.rail {
  padding: 18px 16px;
  overflow-y: auto;
  background: var(--bg);
}
.rail.left { grid-area: left; border-right: 1px solid var(--line); }
.rail.right { grid-area: right; border-left: 1px solid var(--line); }

.rail-title {
  font-family: "IBM Plex Mono", monospace;
  font-size: 10.5px;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--muted);
  margin: 0 0 10px 0;
  display: flex;
  justify-content: space-between;
  align-items: center;
}
.rail-section { margin-bottom: 22px; }

/* Montage picker */
.montage-list { display: flex; flex-direction: column; gap: 2px; }
.montage-btn {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  padding: 8px 10px;
  border-radius: 6px;
  border: 1px solid transparent;
  background: transparent;
  color: var(--ink);
  cursor: pointer;
  text-align: left;
  font: inherit;
  transition: background 0.12s, border-color 0.12s;
}
.montage-btn:hover { background: var(--bg-2); }
.montage-btn.active {
  background: #fff;
  border-color: var(--line);
  box-shadow: 0 1px 0 rgba(0,0,0,0.02);
}
.montage-btn .count {
  font-family: "IBM Plex Mono", monospace;
  font-size: 10.5px;
  color: var(--muted);
  letter-spacing: 0.05em;
}
.montage-btn.active .count { color: var(--accent); }

/* Search */
.search {
  position: relative;
  margin-bottom: 10px;
}
.search input {
  width: 100%;
  padding: 7px 10px 7px 26px;
  border: 1px solid var(--line);
  border-radius: 6px;
  background: #fff;
  font: inherit;
  color: var(--ink);
  outline: none;
  font-family: "IBM Plex Mono", monospace;
  font-size: 12px;
}
.search input:focus { border-color: var(--accent); }
.search svg {
  position: absolute; left: 8px; top: 50%;
  transform: translateY(-50%);
  color: var(--muted);
  pointer-events: none;
}

/* Channel list */
.ch-list {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 2px;
  max-height: 280px;
  overflow-y: auto;
  padding-right: 2px;
}
.ch-chip {
  display: flex;
  align-items: center;
  gap: 5px;
  padding: 4px 6px;
  border-radius: 4px;
  font-family: "IBM Plex Mono", monospace;
  font-size: 10.5px;
  cursor: pointer;
  color: var(--ink-2);
  border: 1px solid transparent;
  background: transparent;
  user-select: none;
  transition: background 0.1s;
}
.ch-chip:hover { background: var(--bg-2); }
.ch-chip.selected { background: #fff; border-color: var(--line); color: var(--ink); }
.ch-chip.dimmed { opacity: 0.35; }
.ch-dot {
  width: 6px; height: 6px; border-radius: 50%;
  background: var(--muted);
  flex-shrink: 0;
}
.ch-chip.hit { background: var(--accent-soft); color: var(--accent); }

/* Stage (3D canvas) */
.stage {
  grid-area: stage;
  position: relative;
  background:
    linear-gradient(180deg, var(--bg) 0%, var(--bg-2) 100%);
  overflow: hidden;
}
.stage canvas { display: block; }

.stage-overlay {
  position: absolute;
  pointer-events: none;
  font-family: "IBM Plex Mono", monospace;
  font-size: 10.5px;
  color: var(--muted);
  letter-spacing: 0.08em;
  text-transform: uppercase;
  z-index: 10;  /* must sit above .stage-pane (2D SVG / 3D canvas) so buttons catch clicks */
}
.stage-overlay.top-left { top: 14px; left: 18px; }
.stage-overlay.top-right { top: 14px; right: 18px; pointer-events: auto; }
.stage-overlay.bottom-left { bottom: 14px; left: 18px; display: flex; gap: 10px; align-items: center; }
.stage-overlay.bottom-right {
  bottom: 14px; right: 18px;
  pointer-events: auto;
  display: flex; gap: 6px;
}

.axis-swatch {
  display: inline-flex; gap: 4px; align-items: center;
  margin-right: 10px;
}
.axis-swatch span:first-child {
  width: 8px; height: 2px; background: currentColor;
}

.view-btn {
  padding: 5px 9px;
  border: 1px solid var(--line);
  background: var(--bg);
  color: var(--ink-2);
  border-radius: 4px;
  font-family: "IBM Plex Mono", monospace;
  font-size: 10.5px;
  cursor: pointer;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}
.view-btn:hover { background: #fff; border-color: var(--ink-2); color: var(--ink); }

/* 3D DOM labels */
.lbl {
  position: absolute;
  left: 0; top: 0;
  font-family: "IBM Plex Mono", monospace;
  pointer-events: none;
  white-space: nowrap;
  user-select: none;
  will-change: transform;
}
.lbl-electrode {
  font-size: 10.5px;
  color: var(--ink);
  font-weight: 500;
  letter-spacing: 0.02em;
  text-shadow: 0 0 3px var(--bg), 0 0 3px var(--bg), 0 0 3px var(--bg);
}
.lbl-electrode.lbl-selected { color: var(--accent); font-weight: 600; }
.lbl-electrode.lbl-hover { color: #e0521f; font-weight: 600; }
.lbl-landmark {
  font-size: 9.5px;
  color: var(--muted);
  letter-spacing: 0.14em;
  text-transform: uppercase;
}

/* Hover tooltip for electrodes */
.tooltip {
  position: absolute;
  pointer-events: none;
  padding: 6px 9px;
  background: #fff;
  border: 1px solid var(--line);
  border-radius: 4px;
  font-family: "IBM Plex Mono", monospace;
  font-size: 11px;
  color: var(--ink);
  white-space: nowrap;
  box-shadow: 0 2px 12px rgba(0,0,0,0.06);
  z-index: 10;
  opacity: 0;
  transform: translate(-50%, calc(-100% - 10px));
  transition: opacity 0.1s;
}
.tooltip.visible { opacity: 1; }
.tooltip .tt-name { font-weight: 600; }
.tooltip .tt-coords { color: var(--muted); margin-top: 2px; }

/* Right rail — selected channel */
.selected-card {
  background: #fff;
  border: 1px solid var(--line);
  border-radius: 6px;
  padding: 12px 14px;
  margin-bottom: 14px;
}
.selected-name {
  font-family: "IBM Plex Mono", monospace;
  font-size: 22px;
  letter-spacing: 0.02em;
}
.selected-region {
  font-family: "IBM Plex Mono", monospace;
  font-size: 10.5px;
  color: var(--muted);
  text-transform: uppercase;
  letter-spacing: 0.12em;
  margin-top: 2px;
}
.coord-grid {
  display: grid;
  grid-template-columns: auto 1fr;
  gap: 3px 12px;
  margin-top: 10px;
  font-family: "IBM Plex Mono", monospace;
  font-size: 11px;
}
.coord-grid dt { color: var(--muted); }
.coord-grid dd { margin: 0; color: var(--ink); }

.stats {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
  border-radius: 6px;
  overflow: hidden;
  margin-bottom: 14px;
}
.stat {
  background: #fff;
  padding: 10px 12px;
}
.stat-label {
  font-family: "IBM Plex Mono", monospace;
  font-size: 9.5px;
  text-transform: uppercase;
  letter-spacing: 0.12em;
  color: var(--muted);
}
.stat-value {
  font-family: "IBM Plex Mono", monospace;
  font-size: 18px;
  margin-top: 3px;
}

/* Region legend */
.legend { display: flex; flex-direction: column; gap: 4px; font-family: "IBM Plex Mono", monospace; font-size: 11px; }
.legend-item { display: flex; align-items: center; gap: 8px; cursor: pointer; padding: 3px 2px; border-radius: 3px; }
.legend-item:hover { background: var(--bg-2); }
.legend-item.off { opacity: 0.35; }
.legend-swatch { width: 10px; height: 10px; border-radius: 50%; }

/* TSV panel */
.tsv-panel {
  grid-area: tsv;
  border-top: 1px solid var(--line);
  background: #fff;
  display: grid;
  grid-template-rows: auto 1fr;
  min-height: 0;
}
.tsv-header {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 10px 16px;
  border-bottom: 1px solid var(--line);
}
.tsv-header-title {
  font-family: "IBM Plex Mono", monospace;
  font-size: 11px;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--ink);
}
.tsv-header-sub {
  font-family: "IBM Plex Mono", monospace;
  font-size: 10.5px;
  color: var(--muted);
}
.tsv-actions { margin-left: auto; display: flex; gap: 6px; }
.btn {
  padding: 6px 12px;
  border: 1px solid var(--line);
  background: var(--bg);
  color: var(--ink);
  font: inherit;
  font-family: "IBM Plex Mono", monospace;
  font-size: 11px;
  letter-spacing: 0.05em;
  border-radius: 4px;
  cursor: pointer;
  transition: background 0.12s, border-color 0.12s;
}
.btn:hover { background: #fff; border-color: var(--ink-2); }
.btn.primary {
  background: var(--ink);
  color: var(--bg);
  border-color: var(--ink);
}
.btn.primary:hover { background: var(--accent); border-color: var(--accent); color: #fff; }

.tsv-view {
  padding: 12px 16px;
  overflow: auto;
  font-family: "IBM Plex Mono", monospace;
  font-size: 11.5px;
  line-height: 1.55;
  color: var(--ink-2);
  min-height: 0;
  background: #fcfbf8;
}
.tsv-view table { border-collapse: collapse; }
.tsv-view th, .tsv-view td {
  padding: 2px 14px 2px 0;
  text-align: left;
  font-weight: 400;
  white-space: nowrap;
}
.tsv-view thead th {
  color: var(--muted);
  font-size: 10px;
  text-transform: uppercase;
  letter-spacing: 0.12em;
  border-bottom: 1px solid var(--line);
  padding-bottom: 6px;
}
.tsv-view tbody tr { cursor: pointer; }
.tsv-view tbody tr:hover { background: var(--accent-soft); color: var(--ink); }
.tsv-view tbody tr.selected { background: var(--accent-soft); color: var(--accent); }
.tsv-view tbody tr.dimmed { opacity: 0.3; }

/* Tweaks panel */
.tweaks-panel {
  position: absolute;
  right: 16px;
  top: 64px;
  width: 230px;
  background: #fff;
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 14px;
  box-shadow: 0 4px 24px rgba(0,0,0,0.06);
  z-index: 20;
  display: none;
}
.tweaks-panel.visible { display: block; }
.tweaks-title {
  font-family: "IBM Plex Mono", monospace;
  font-size: 10.5px;
  text-transform: uppercase;
  letter-spacing: 0.14em;
  color: var(--muted);
  margin-bottom: 10px;
}
.tweak-row { margin-bottom: 10px; }
.tweak-row label {
  display: block;
  font-family: "IBM Plex Mono", monospace;
  font-size: 10.5px;
  color: var(--ink-2);
  margin-bottom: 4px;
}
.tweak-row input[type="range"] { width: 100%; }
.tweak-toggle {
  display: flex;
  gap: 4px;
  flex-wrap: wrap;
  margin-top: 2px;
}
.tweak-toggle .view-btn.on {
  background: var(--ink);
  color: var(--bg);
  border-color: var(--ink);
}

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

/* =========================================================
   View containers (2D top / 3D head)
   ========================================================= */
.stage-pane {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
}

/* 2D top-view SVG */
.topo-svg {
  width: 100%;
  height: 100%;
  display: block;
}
.topo-svg .topo-dot {
  cursor: pointer;
  transition: stroke-width 120ms ease;
}

/* View-mode switcher (top-right of stage) */
.view-mode-switch {
  display: inline-flex;
  gap: 0;
  background: #fff;
  border: 1px solid var(--line);
  border-radius: 4px;
  overflow: hidden;
  box-shadow: 0 1px 2px rgba(0,0,0,0.03);
  white-space: nowrap;
}
.view-mode-switch .view-btn {
  border: none;
  border-radius: 0;
  background: transparent;
  padding: 7px 14px;
  font-family: "IBM Plex Mono", monospace;
  font-size: 10.5px;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--muted);
  cursor: pointer;
  white-space: nowrap;
  line-height: 1;
  transition: background 0.14s ease, color 0.14s ease;
}
.view-mode-switch .view-btn + .view-btn {
  border-left: 1px solid var(--line);
}
.view-mode-switch .view-btn.on {
  background: var(--ink);
  color: #fff;
}
.view-mode-switch .view-btn:hover:not(.on) {
  color: var(--ink);
  background: var(--bg-2);
}
.view-mode-switch .view-btn:active {
  transform: translateY(0.5px);
}

/* =========================================================
   Drag-and-drop overlay — shows when files are being dragged
   over the window. Tracks 'body.drag-active' class, toggled
   by the JS dragenter/leave counter.
   ========================================================= */
body.drag-active::before {
  content: "";
  position: fixed;
  inset: 0;
  background: color-mix(in oklab, var(--bg) 82%, transparent);
  backdrop-filter: blur(4px);
  -webkit-backdrop-filter: blur(4px);
  z-index: 90;
  pointer-events: none;
  animation: drop-fade-in 140ms ease-out;
}
body.drag-active::after {
  content: "[ DROP ELECTRODES.TSV ]";
  position: fixed;
  inset: 24px;
  display: grid;
  place-items: center;
  border: 1.5px dashed var(--ink);
  border-radius: 10px;
  font-family: "IBM Plex Mono", monospace;
  font-size: 14px;
  letter-spacing: 0.32em;
  color: var(--ink);
  font-weight: 500;
  z-index: 91;
  pointer-events: none;
  animation: drop-fade-in 180ms ease-out;
}
@keyframes drop-fade-in {
  from { opacity: 0; }
  to   { opacity: 1; }
}

/* =========================================================
   Stage caption — metadata under the 2D topomap: channel
   count, fitted head radius, coordinate space. Styled like
   an engraved instrument legend.
   ========================================================= */
.stage-caption {
  position: absolute;
  bottom: 14px;
  left: 18px;
  pointer-events: none;
  font-family: "IBM Plex Mono", monospace;
  font-size: 10.5px;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--muted);
  z-index: 2;
  display: flex;
  gap: 10px;
  align-items: center;
}
.stage-caption .val { color: var(--ink-2); font-weight: 500; }
.stage-caption .sep { color: var(--ink-3); font-weight: 400; }

/* =========================================================
   Embed mode (?embed=1) — iframe layout. Hides navigational
   chrome so the host page owns that context. Only the
   topomap + caption are visible by default. ?tweaks=1 makes
   the tweaks panel visible on top.
   ========================================================= */
body.embed .rail,
body.embed .tsv-panel,
body.embed .header-right,
body.embed .brand-sub,
body.embed #stage-hint {
  display: none;
}
body.embed .app {
  grid-template-columns: 0 1fr 0;
  grid-template-rows: 34px 1fr 0;
}
body.embed .header {
  padding: 0 12px;
  min-height: 34px;
}
body.embed .brand-title { font-size: 11px; }

/* Error banner used in embed mode — when the rails are hidden
   the status line isn't visible, so errors need their own
   surface. Also appears in non-embed mode as a redundant cue
   (it's styled to be visible without being intrusive). */
.embed-error {
  position: fixed;
  top: 14px;
  left: 14px;
  right: 14px;
  max-width: 600px;
  margin: 0 auto;
  padding: 8px 12px;
  background: #fff5f2;
  color: var(--danger, #b94a34);
  border: 1px solid var(--danger, #b94a34);
  border-radius: 6px;
  font-family: "IBM Plex Mono", monospace;
  font-size: 11px;
  letter-spacing: 0.06em;
  z-index: 200;
  box-shadow: 0 2px 10px rgba(0, 0, 0, 0.05);
  animation: drop-fade-in 180ms ease-out;
}
.embed-error[hidden] { display: none; }