styles.css

/* ============================================================
   styles.css — EEG Trace Viewer.

   Visual identity is mostly shared with the sister electrode-explorer
   (electrodes.eegdash.org): IBM Plex Sans/Mono pairing, mono+
   uppercase+tracked treatment for UI chrome, ink inversion as the
   only "primary" state. Page background is neutral white here
   (electrode-explorer keeps its cream paper look). The viewer is a
   scientific instrument, not a SaaS dashboard.
   ============================================================ */
:root {
  --bg:        #ffffff;       /* page */
  --bg-2:      #f3f3f3;       /* deeper page */
  --surface:   #ffffff;       /* elevated card */
  --ink:       #17181a;
  --ink-2:     #3a3d42;
  --ink-3:     #797d83;       /* darkened from #b5b8bd for WCAG AA contrast on --paper */
  --muted:     #6a6e74;       /* darkened from #8b8e94 to clear the 4.5:1 AA threshold */
  --line:      #dddddd;
  --line-2:    #e8e8e8;
  --accent:    oklch(0.55 0.15 240);
  --accent-soft: oklch(0.92 0.04 240);
  --bad:       #D55E00;       /* Okabe-Ito vermillion, also used by traces.js */
  --good:      oklch(0.62 0.14 150);

  --mono: 'IBM Plex Mono', ui-monospace, SFMono-Regular, Menlo, monospace;
  --sans: 'IBM Plex Sans', system-ui, -apple-system, sans-serif;
  --display: 'Fraunces', 'Iowan Old Style', 'Cambria', 'Georgia', serif;

  /* Reusable tracked-uppercase treatment for UI chrome. Use with
     `font: var(--label-font); letter-spacing: var(--label-tracking);
     text-transform: uppercase;` to match every other label. */
  --label-tracking: 0.12em;
}

* { box-sizing: border-box; }

html, body {
  margin: 0;
  padding: 0;
  height: 100%;
  background: var(--bg);
  color: var(--ink);
  font-family: var(--sans);
  font-size: 13px;
  line-height: 1.45;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

code {
  font-family: var(--mono);
  font-size: 12px;
  background: var(--bg-2);
  padding: 1px 5px;
  border-radius: 3px;
  letter-spacing: 0.01em;
}

::-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; }

.app {
  display: grid;
  grid-template-columns: 320px 1fr;
  grid-template-rows: 52px 1fr;
  height: 100vh;
}

/* ----- header --------------------------------------------- */

.header {
  grid-column: 1 / -1;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 18px;
  background: var(--bg);
  border-bottom: 1px solid var(--line);
  z-index: 5;
}

.brand { display: flex; align-items: center; gap: 12px; }
.brand-mark {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 22px;
  height: 22px;
  color: var(--accent);
}
.brand-mark svg { width: 100%; height: 100%; display: block; }

.brand-title {
  font-family: var(--mono);
  font-size: 12px;
  letter-spacing: var(--label-tracking);
  text-transform: uppercase;
  color: var(--ink);
  font-weight: 500;
  display: inline-flex;
  align-items: baseline;
  gap: 7px;
}
/* Editorial-serif display treatment for the "EEG" mark — single
   monogram-like flourish that reads "scientific journal" instead of
   "SaaS dashboard". Optical-size 144 picks Fraunces' display cut. */
.brand-title-display {
  font-family: var(--display);
  font-optical-sizing: auto;
  font-variation-settings: 'opsz' 144, 'SOFT' 50;
  font-style: italic;
  font-weight: 400;
  font-size: 22px;
  line-height: 1;
  letter-spacing: -0.01em;
  text-transform: none;
  color: var(--accent);
  position: relative;
  top: 2px;
}
.brand-sub {
  font-family: var(--mono);
  font-size: 10.5px;
  letter-spacing: 0.06em;
  color: var(--muted);
  margin-left: 12px;
  padding-left: 12px;
  border-left: 1px solid var(--line);
}

.header-right {
  display: flex;
  gap: 5px;
  align-items: center;
}

/* eegdash brand link. Sits to the right of the pills with a thin
   left rule so it reads as attribution, not as a fifth pill. The
   logo's intrinsic colours match the page's ink hierarchy already
   (it's a black wordmark on cream); we just scale it. */
.brand-eegdash {
  display: inline-flex;
  align-items: center;
  height: 22px;
  margin-left: 12px;
  padding-left: 12px;
  border-left: 1px solid var(--line);
  text-decoration: none;
  opacity: 0.55;                      /* attribution weight in standalone */
  transition: opacity 140ms;
}
.brand-eegdash:hover { opacity: 1; }
.brand-eegdash img { height: 100%; width: auto; display: block; }
.pill {
  font-family: var(--mono);
  font-size: 10.5px;
  letter-spacing: 0.04em;
  padding: 3px 9px;
  background: transparent;
  border: 1px solid var(--line);
  border-radius: 999px;
  color: var(--ink-2);
  font-variant-numeric: tabular-nums;
}

/* Time-mode toggle — same visual weight as a pill, but interactive.
   Lives in the header next to the readout pills; flips between
   "rel" (seconds-from-start) and "clock" (HH:MM:SS) on click. */
#time-mode-toggle {
  appearance: none;
  font-family: var(--mono);
  font-size: 10.5px;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  padding: 3px 11px;
  background: transparent;
  border: 1px solid var(--line);
  border-radius: 999px;
  color: var(--ink-2);
  cursor: pointer;
  transition: border-color 140ms, color 140ms, background 140ms;
  margin-left: 2px;
}
#time-mode-toggle:hover:not(:disabled) {
  border-color: var(--ink-2);
  color: var(--ink);
}
#time-mode-toggle[data-mode="clock"] {
  background: var(--ink);
  border-color: var(--ink);
  color: var(--bg);
}
#time-mode-toggle:disabled {
  opacity: 0.35;
  cursor: not-allowed;
}
.pill[data-changed="true"] {
  /* Subtle pulse when a pill's value changes — used for fs/channels/duration
     after the binary header resolves them. Driven by JS toggling the attr. */
  animation: pill-pulse 320ms ease-out;
}
@keyframes pill-pulse {
  0%   { background: var(--accent-soft); border-color: var(--accent); }
  100% { background: transparent;        border-color: var(--line); }
}

/* ----- left rail ------------------------------------------ */

.rail.left {
  background: var(--bg);
  border-right: 1px solid var(--line);
  overflow-y: auto;
  padding: 18px 16px 24px;
}

.rail-section { margin-bottom: 22px; }
.rail-title {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  font-family: var(--mono);
  font-size: 10.5px;
  letter-spacing: var(--label-tracking);
  text-transform: uppercase;
  color: var(--muted);
  margin: 0 0 10px;
  font-weight: 500;
}
.count {
  font-family: var(--mono);
  font-size: 10.5px;
  letter-spacing: 0.04em;
  color: var(--muted);
  font-variant-numeric: tabular-nums;
}

.status {
  font-family: var(--mono);
  font-size: 11px;
  line-height: 1.55;
  letter-spacing: 0.02em;
  word-break: break-all;
  color: var(--ink);
}
.status strong { font-weight: 500; }
.status .err {
  color: var(--bad);
  font-weight: 500;
  letter-spacing: 0.04em;
}

.provenance { margin-top: 10px; font-size: 11px; line-height: 1.6; }
.provenance > div { margin-bottom: 1px; }
.provenance code {
  font-size: 10px;
  background: var(--surface);
  border: 1px solid var(--line-2);
  word-break: break-all;
}
.prov-key {
  display: inline-block;
  min-width: 88px;
  font-family: var(--mono);
  font-size: 10px;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--muted);
}
.prov-empty {
  color: var(--muted);
  font-family: var(--mono);
  font-size: 10.5px;
  letter-spacing: 0.04em;
  font-style: normal;
  padding: 2px 0;
}

/* ----- channel + event lists ------------------------------ */

.ch-list, .ev-list {
  max-height: 240px;
  overflow-y: auto;
  font-family: var(--mono);
  font-size: 11px;
  border: 1px solid var(--line);
  border-radius: 6px;
  padding: 4px 0;
  background: var(--surface);
}
.ch-row, .ev-row {
  display: flex;
  align-items: center;
  gap: 6px;
  padding: 3px 10px;
  letter-spacing: 0.02em;
}
.ch-row { cursor: pointer; }
.ch-row:hover, .ev-row:hover { background: var(--bg-2); }
.ch-row.is-bad { background: color-mix(in oklab, var(--bad) 6%, transparent); }
.ch-name { font-weight: 500; color: var(--ink); }
.ch-type, .ch-units, .ev-label {
  color: var(--muted);
  font-size: 10px;
  letter-spacing: 0.04em;
  text-transform: uppercase;
}
.ev-onset {
  color: var(--accent);
  min-width: 62px;
  font-variant-numeric: tabular-nums;
}
.bad-dot {
  width: 5px; height: 5px; border-radius: 50%;
  background: var(--bad);
  flex-shrink: 0;
  box-shadow: 0 0 0 1px color-mix(in oklab, var(--bad) 40%, transparent);
}
.muted {
  color: var(--muted);
  padding: 8px 12px;
  font-family: var(--mono);
  font-size: 10.5px;
  letter-spacing: 0.04em;
  font-style: normal;
}

/* ----- channel color swatches ----------------------------- */

.color-swatch-row {
  display: flex;
  gap: 8px;
  align-items: center;
  padding: 4px 0;
}

.ch-type-label {
  font-family: var(--mono);
  font-size: 11px;
  min-width: 40px;
  color: var(--muted);
  letter-spacing: 0.04em;
  text-transform: uppercase;
}

.color-picker-row {
  display: flex;
  gap: 4px;
  flex-wrap: wrap;
}

.color-swatch {
  width: 16px;
  height: 16px;
  border-radius: 3px;
  border: 1px solid color-mix(in oklab, currentColor 25%, transparent);
  cursor: pointer;
  padding: 0;
  flex-shrink: 0;
  position: relative;
  transition: transform 140ms cubic-bezier(0.22, 1, 0.36, 1),
              box-shadow 140ms;
}

.color-swatch:hover {
  transform: scale(1.18);
  box-shadow: 0 1px 3px color-mix(in oklab, var(--ink) 18%, transparent);
}

/* Active state: a fine ink ring + subtle outer halo so the user sees
   exactly which colour is in play, without obscuring its hue. */
.color-swatch.active {
  box-shadow:
    inset 0 0 0 1px var(--bg),
    0 0 0 1.5px var(--ink);
}

/* ----- filter controls (F08) ----------------------------- */
/* Three-row instrument panel: HP / LP / Notch. Custom checkboxes
   so the row reads as a tiny console — square checkbox, mono label,
   numeric readout, faded "Hz" suffix. */

#filter-controls {
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.filter-row {
  display: grid;
  grid-template-columns: auto 1fr auto;
  align-items: center;
  gap: 10px;
  padding: 4px 0;
  font-family: var(--mono);
  font-size: 10.5px;
  letter-spacing: 0.04em;
  color: var(--ink-2);
  text-transform: uppercase;
}

/* Square checkbox + label — clickable as one unit. */
.filter-row label {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  cursor: pointer;
  color: var(--muted);
  letter-spacing: 0.06em;
  user-select: none;
}
.filter-row label:has(input:checked) { color: var(--ink); }

.filter-row input[type="checkbox"] {
  appearance: none;
  -webkit-appearance: none;
  width: 12px;
  height: 12px;
  border: 1px solid var(--ink-3);
  border-radius: 2px;
  background: var(--surface);
  cursor: pointer;
  position: relative;
  transition: border-color 120ms, background 120ms;
  flex-shrink: 0;
}
.filter-row input[type="checkbox"]:hover { border-color: var(--ink-2); }
.filter-row input[type="checkbox"]:checked {
  background: var(--ink);
  border-color: var(--ink);
}
.filter-row input[type="checkbox"]:checked::after {
  content: "";
  position: absolute;
  top: 1px; left: 3.5px;
  width: 3px; height: 6px;
  border: solid var(--bg);
  border-width: 0 1.5px 1.5px 0;
  transform: rotate(45deg);
}

.filter-row input[type="number"] {
  font: inherit;
  font-variant-numeric: tabular-nums;
  text-transform: none;
  letter-spacing: 0;
  color: var(--ink);
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: 4px;
  padding: 3px 6px;
  width: 100%;
  min-width: 0;
  outline: none;
  -moz-appearance: textfield;
}
.filter-row input[type="number"]::-webkit-outer-spin-button,
.filter-row input[type="number"]::-webkit-inner-spin-button {
  -webkit-appearance: none;
  margin: 0;
}
.filter-row input[type="number"]:hover  { border-color: var(--ink-2); }
.filter-row input[type="number"]:focus  { border-color: var(--accent); }

.filter-row select {
  font: inherit;
  font-variant-numeric: tabular-nums;
  text-transform: none;
  letter-spacing: 0;
  color: var(--ink);
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: 4px;
  padding: 3px 6px;
  outline: none;
  cursor: pointer;
  grid-column: 2 / -1;
}
.filter-row select:hover { border-color: var(--ink-2); }
.filter-row select:focus { border-color: var(--accent); }

.filter-unit {
  font-family: var(--mono);
  font-size: 9.5px;
  letter-spacing: 0.08em;
  color: var(--muted);
  text-transform: uppercase;
}

/* ----- view controls -------------------------------------- */

.view-controls {
  display: flex;
  flex-direction: column;
  gap: 10px;
  font-family: var(--mono);
  font-size: 10.5px;
  letter-spacing: 0.05em;
  text-transform: uppercase;
  color: var(--muted);
}
.view-controls label {
  display: grid;
  grid-template-columns: 56px 1fr auto;
  align-items: center;
  gap: 10px;
}

.view-controls select {
  font: inherit;
  text-transform: uppercase;
  letter-spacing: 0.04em;
  color: var(--ink);
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: 6px;
  padding: 5px 8px;
  outline: none;
  cursor: pointer;
}
.view-controls select:hover { border-color: var(--ink-2); }
.view-controls select:focus { border-color: var(--accent); }

.view-controls input[type="range"] {
  -webkit-appearance: none;
  appearance: none;
  background: transparent;
  height: 18px;
  cursor: pointer;
}
.view-controls input[type="range"]::-webkit-slider-runnable-track {
  height: 2px;
  background: var(--line);
  border-radius: 1px;
}
.view-controls input[type="range"]::-moz-range-track {
  height: 2px;
  background: var(--line);
  border-radius: 1px;
}
.view-controls input[type="range"]::-webkit-slider-thumb {
  -webkit-appearance: none;
  appearance: none;
  width: 12px;
  height: 12px;
  border-radius: 50%;
  background: var(--ink);
  margin-top: -5px;
  border: 2px solid var(--bg);
  transition: background 120ms;
}
.view-controls input[type="range"]:hover::-webkit-slider-thumb { background: var(--accent); }
.view-controls input[type="range"]::-moz-range-thumb {
  width: 12px;
  height: 12px;
  border-radius: 50%;
  background: var(--ink);
  border: 2px solid var(--bg);
}
#gain-readout {
  color: var(--ink);
  min-width: 38px;
  text-align: right;
  font-variant-numeric: tabular-nums;
}

.view-tip {
  margin-top: 12px;
  font-family: var(--mono);
  font-size: 10px;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  color: var(--muted);
  line-height: 1.6;
}
.view-tip kbd {
  display: inline-block;
  font-family: var(--mono);
  font-size: 9.5px;
  padding: 1px 5px;
  margin: 0 1px;
  border: 1px solid var(--line);
  border-bottom-width: 2px;
  border-radius: 3px;
  background: var(--surface);
  color: var(--ink-2);
  letter-spacing: 0;
  text-transform: none;
}

.electrode-link {
  display: inline-flex;
  align-items: center;
  gap: 4px;
  margin-top: 14px;
  font-family: var(--mono);
  font-size: 10px;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--accent);
  text-decoration: none;
  padding: 6px 9px;
  border: 1px solid var(--line);
  border-radius: 4px;
  background: var(--surface);
  transition: border-color 120ms, color 120ms, transform 120ms;
}
.electrode-link[hidden] { display: none; }
.electrode-link:hover {
  border-color: var(--accent);
  transform: translateX(1px);
}

/* ----- stage --------------------------------------------- */

.stage {
  position: relative;
  overflow: hidden;
  background:
    radial-gradient(at 100% 0%, color-mix(in oklab, var(--accent) 4%, transparent) 0, transparent 60%),
    linear-gradient(180deg, var(--bg) 0%, var(--bg-2) 100%);
}

/* Empty-stage watermark: a faint waveform glyph centered behind the
   "No recording loaded" copy. Only visible while the stage-hint is
   showing (i.e. before a recording loads); once traces appear, they
   sit on the canvas and the watermark is moot. SVG is inlined as a
   data URI so we don't fire an extra HTTP request on the empty path. */
.stage::before {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  z-index: 0;
  background-image: url("data:image/svg+xml;utf8,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 220 220' fill='none' stroke='%230072B2' stroke-width='1.2' stroke-linecap='round' stroke-linejoin='round' opacity='0.06'%3E%3Ccircle cx='110' cy='110' r='95' stroke-opacity='0.4'/%3E%3Cpath d='M20 110 Q40 110 50 80 T70 140 T90 80 T110 140 T130 90 T150 120 T170 110 L200 110'/%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: center;
  background-size: 320px 320px;
  transition: opacity 320ms;
}
.stage:has(.traces:not([hidden]))::before { opacity: 0; }

.stage-hint {
  position: relative;       /* sit above the empty-stage watermark */
  z-index: 1;
  padding: 32px 36px;
  max-width: 620px;
  font-family: var(--mono);
  font-size: 12px;
  line-height: 1.7;
  letter-spacing: 0.02em;
  color: var(--ink-2);
}
.stage-hint p:first-child {
  font-size: 11px;
  letter-spacing: var(--label-tracking);
  text-transform: uppercase;
  color: var(--muted);
  margin-bottom: 10px;
  font-weight: 500;
}
.stage-hint code {
  background: var(--surface);
  border: 1px solid var(--line);
  font-size: 11px;
}

.traces {
  display: block;
  width: 100%;
  height: 100%;
  cursor: grab;
  touch-action: none;
}
.traces:active { cursor: grabbing; }
/* Honour the HTML `hidden` attribute. Without this, the explicit
   `display: block` above would mask `hidden=""` and the canvas would
   stay visible — Playwright's CSS-based `toBeHidden()` would then
   silently return "visible" while the JS code thinks it hid the
   canvas. Keeps the attribute and the visual state in sync. */
.traces[hidden] { display: none; }

/* Engraved instrument legend in the stage's bottom-left corner.
   Mirrors the sister explorer's `.stage-caption` treatment so both
   tools read as part of the same instrument family. Populated by JS
   from the loaded recording's metadata. */
.stage-caption {
  position: absolute;
  bottom: 14px;
  left: 18px;
  pointer-events: none;
  font-family: var(--mono);
  font-size: 10px;
  letter-spacing: var(--label-tracking);
  text-transform: uppercase;
  color: var(--muted);
  display: flex;
  gap: 10px;
  align-items: center;
  z-index: 2;
}
.stage-caption[hidden] { display: none; }
.stage-caption .val { color: var(--ink-2); font-weight: 500; }
.stage-caption .sep { color: var(--ink-3); }

/* ----- cursor readout ------------------------------------ */

/* Info bar: fixed strip at the bottom of the stage. Reads as an
   instrument readout — leading "CURSOR" label, hairline column
   separators, tabular figures so digits don't dance during pan. */
.cursor-info-bar {
  position: absolute;
  bottom: 0;
  left: 0;
  right: 0;
  z-index: 3;
  display: flex;
  gap: 0;
  align-items: stretch;
  padding: 0;
  background: color-mix(in oklab, var(--bg) 88%, transparent);
  backdrop-filter: blur(4px);
  -webkit-backdrop-filter: blur(4px);
  font-family: var(--mono);
  font-size: 10.5px;
  letter-spacing: 0.04em;
  color: var(--ink-2);
  font-variant-numeric: tabular-nums;
  pointer-events: none;
  border-top: 1px solid var(--line);
}
.cursor-info-bar[hidden] { display: none; }
/* Leading "CURSOR" label as a fixed plate, pseudo-element so we don't
   touch markup. The bar's children carry their own values. */
.cursor-info-bar::before {
  content: "Cursor";
  display: inline-flex;
  align-items: center;
  padding: 4px 12px;
  font-size: 9.5px;
  letter-spacing: var(--label-tracking);
  text-transform: uppercase;
  color: var(--muted);
  border-right: 1px solid var(--line);
  background: color-mix(in oklab, var(--bg-2) 60%, transparent);
}

.cursor-info-bar > span {
  padding: 4px 14px;
  display: inline-flex;
  align-items: center;
}
.cursor-time   { color: var(--accent); min-width: 110px; }
.cursor-channel { font-weight: 500; color: var(--ink); min-width: 56px;
                  border-left: 1px solid var(--line-2);
                  border-right: 1px solid var(--line-2); }
.cursor-value  { color: var(--ink-2); min-width: 90px; }

/* Dot: small circle tracking the pointer on the canvas. */
.cursor-dot {
  position: absolute;
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--accent);
  border: 1.5px solid var(--bg);
  box-shadow: 0 0 0 1px var(--accent);
  pointer-events: none;
  transform: translate(-50%, -50%);
  z-index: 4;
}
.cursor-dot[hidden] { display: none; }

/* ----- embed mode ---------------------------------------- */
/* (?embed=1) The host page provides outer context (an eegdash docs
   page already has the wordmark, breadcrumbs, etc.), so we collapse
   to a thin header — the eegdash mark stays as a brand anchor so
   the iframe reads as part of the parent product. The rail hides;
   only traces + the engraved stage caption remain. */

body.embed { background: transparent; }
body.embed .rail.left { display: none; }
body.embed .app {
  grid-template-columns: 1fr;
  grid-template-rows: 38px 1fr;
}
body.embed .header {
  background: transparent;
  padding: 0 14px;
  min-height: 38px;
}
body.embed .brand-title,
body.embed .brand-sub,
body.embed .header-right .pill { display: none; }
body.embed .brand-mark { width: 18px; height: 18px; }
body.embed .brand-eegdash {
  margin-left: 0;
  padding-left: 0;
  border-left: 0;
  opacity: 1;                  /* the wordmark IS the brand here */
  height: 24px;
}
body.embed .stage {
  background: transparent;     /* let the host page bleed through */
}
body.embed .stage-hint { padding: 16px; font-size: 11px; }
body.embed .stage-caption {
  bottom: 8px;
  left: 12px;
  font-size: 9.5px;
}

/* ----- drag-drop overlay --------------------------------- */

body.drag-active::before {
  content: "";
  position: fixed;
  inset: 0;
  background: color-mix(in oklab, var(--bg) 78%, transparent);
  backdrop-filter: blur(4px);
  -webkit-backdrop-filter: blur(4px);
  z-index: 90;
  pointer-events: none;
  animation: drop-fade 140ms ease-out;
}
body.drag-active::after {
  content: "[ DROP BIDS RECORDING ]";
  position: fixed;
  inset: 24px;
  display: grid;
  place-items: center;
  border: 1.5px dashed var(--ink);
  border-radius: 10px;
  font-family: var(--mono);
  font-size: 14px;
  letter-spacing: 0.32em;
  color: var(--ink);
  font-weight: 500;
  z-index: 91;
  pointer-events: none;
  animation: drop-fade 180ms ease-out;
}
@keyframes drop-fade {
  from { opacity: 0; }
  to   { opacity: 1; }
}

/* Subtle staggered fade-in for the rail content on first load.
   Makes the panel feel "loaded" rather than just appearing. */
@keyframes rail-fade {
  from { opacity: 0; transform: translateY(2px); }
  to   { opacity: 1; transform: none; }
}
.rail.left .rail-section {
  animation: rail-fade 240ms ease-out backwards;
}
.rail.left .rail-section:nth-child(1) { animation-delay: 40ms; }
.rail.left .rail-section:nth-child(2) { animation-delay: 80ms; }
.rail.left .rail-section:nth-child(3) { animation-delay: 120ms; }
.rail.left .rail-section:nth-child(4) { animation-delay: 160ms; }
@media (prefers-reduced-motion: reduce) {
  .rail.left .rail-section { animation: none; }
  body.drag-active::before, body.drag-active::after { animation: none; }
  .pill[data-changed="true"] { animation: none; }
}

/* ----- overlay system (F02 shortcuts, F03 metadata) ---------- */

.overlay-backdrop {
  position: absolute;
  inset: 0;
  background: color-mix(in oklab, var(--ink) 35%, transparent);
  backdrop-filter: blur(2px);
  -webkit-backdrop-filter: blur(2px);
  display: flex;
  align-items: center;
  justify-content: center;
  animation: overlay-fade-in 140ms ease-out;
}

@keyframes overlay-fade-in {
  from { opacity: 0; }
  to   { opacity: 1; }
}

.overlay-panel {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: 10px;
  box-shadow: 0 8px 40px color-mix(in oklab, var(--ink) 22%, transparent);
  min-width: 360px;
  max-width: 620px;
  max-height: 82vh;
  overflow-y: auto;
  padding: 28px 32px 32px;
  position: relative;
  animation: overlay-panel-in 160ms cubic-bezier(0.22, 1, 0.36, 1);
}

@keyframes overlay-panel-in {
  from { opacity: 0; transform: translateY(8px) scale(0.97); }
  to   { opacity: 1; transform: none; }
}

.overlay-header {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  margin-bottom: 22px;
}

.overlay-header h2 {
  font-family: var(--mono);
  font-size: 13px;
  font-weight: 600;
  letter-spacing: var(--label-tracking);
  text-transform: uppercase;
  color: var(--ink);
  margin: 0;
}

.overlay-close {
  appearance: none;
  background: transparent;
  border: 1px solid var(--line);
  border-radius: 5px;
  color: var(--muted);
  cursor: pointer;
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: 0.06em;
  padding: 3px 9px;
  text-transform: uppercase;
  transition: border-color 120ms, color 120ms;
  flex-shrink: 0;
  margin-left: 16px;
}
.overlay-close:hover {
  border-color: var(--ink-2);
  color: var(--ink);
}

/* Overlays are fixed to the viewport so they cover all grid content
   and Playwright can see non-zero bounding box. The `hidden` HTML
   attribute suppresses them; removing it reveals the overlay. */
#shortcuts-overlay,
#metadata-overlay {
  position: fixed;
  inset: 0;
  z-index: 100;
  display: flex;
  align-items: center;
  justify-content: center;
}
#shortcuts-overlay[hidden],
#metadata-overlay[hidden] {
  display: none;
}

/* ----- shortcut rows (F02) ----------------------------------- */

.shortcut-rows {
  display: grid;
  grid-template-columns: auto 1fr;
  gap: 6px 18px;
  align-items: baseline;
}

.shortcut-key {
  font-family: var(--mono);
  font-size: 11px;
  white-space: nowrap;
}

.shortcut-key kbd {
  display: inline-block;
  font-family: var(--mono);
  font-size: 10.5px;
  padding: 2px 7px;
  border: 1px solid var(--line);
  border-bottom-width: 2px;
  border-radius: 4px;
  background: var(--bg-2);
  color: var(--ink-2);
  letter-spacing: 0;
  text-transform: none;
}

.shortcut-desc {
  font-family: var(--sans);
  font-size: 12px;
  color: var(--ink-2);
  line-height: 1.4;
}

.shortcut-section-title {
  font-family: var(--mono);
  font-size: 9.5px;
  letter-spacing: var(--label-tracking);
  text-transform: uppercase;
  color: var(--muted);
  margin: 16px 0 8px;
  grid-column: 1 / -1;
  font-weight: 500;
}
.shortcut-section-title:first-child { margin-top: 0; }

/* ----- metadata table (F03) ---------------------------------- */

.meta-section {
  margin-bottom: 24px;
}
.meta-section:last-child { margin-bottom: 0; }

.meta-section-title {
  font-family: var(--mono);
  font-size: 9.5px;
  letter-spacing: var(--label-tracking);
  text-transform: uppercase;
  color: var(--muted);
  font-weight: 500;
  margin: 0 0 10px;
  padding-bottom: 6px;
  border-bottom: 1px solid var(--line-2);
}

.metadata-table {
  width: 100%;
  border-collapse: collapse;
  font-family: var(--mono);
  font-size: 11.5px;
}
.metadata-table tr + tr td { border-top: 1px solid var(--line-2); }
.metadata-table td {
  padding: 5px 6px;
  vertical-align: top;
  color: var(--ink-2);
  line-height: 1.4;
}
.metadata-table td:first-child {
  color: var(--muted);
  font-size: 10.5px;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  white-space: nowrap;
  padding-right: 18px;
  width: 110px;
}
.metadata-table td:last-child {
  color: var(--ink);
  word-break: break-all;
}

.meta-section-bids code {
  display: block;
  margin: 3px 0;
  font-size: 10px;
  word-break: break-all;
  background: var(--bg-2);
  border: 1px solid var(--line-2);
  padding: 3px 7px;
  border-radius: 3px;
}

.meta-section-channels table {
  width: 100%;
  border-collapse: collapse;
  font-family: var(--mono);
  font-size: 11px;
}
.meta-section-channels table tr + tr td { border-top: 1px solid var(--line-2); }
.meta-section-channels table td {
  padding: 3px 6px;
  color: var(--ink-2);
}
.meta-section-channels table td:first-child {
  font-weight: 500;
  color: var(--ink);
  width: 100px;
}
.meta-section-channels table .bad-dot {
  display: inline-block;
  width: 5px; height: 5px;
  border-radius: 50%;
  background: var(--bad);
  margin-right: 5px;
  vertical-align: middle;
}