/* ============================================================
   SDR Web — Microsoft Fluent 2 (dark theme)
   Token values from fluent2.microsoft.design.
   ============================================================ */

:root {
  /* ---- Neutrals (Fluent 2 grey scale, dark-theme aliases) ---- */
  --color-bg-1:            #1f1f1f;
  --color-bg-1-hover:      #2e2e2e;
  --color-bg-1-pressed:    #292929;
  --color-bg-2:            #1a1a1a;
  --color-bg-3:            #141414;
  --color-bg-4:            #0a0a0a;
  --color-bg-5:            #000000;
  --color-bg-6:            #333333;
  --color-bg-card:         #292929;
  --color-bg-card-hover:   #2e2e2e;
  --color-subtle-hover:    #383838;
  --color-subtle-pressed:  #2e2e2e;

  --color-fg-1:            #ffffff;
  --color-fg-2:            #d6d6d6;
  --color-fg-3:            #adadad;
  --color-fg-4:            #999999;
  --color-fg-disabled:     #5c5c5c;

  --color-stroke-1:        #666666;
  --color-stroke-2:        #525252;
  --color-stroke-subtle:   #424242;
  --color-stroke-accessible: #adadad;
  --color-stroke-divider:  #2e2e2e;

  /* ---- Brand (communication blue / cyan, dark-theme) ---- */
  --color-brand-bg:           #115ea3;
  --color-brand-bg-hover:     #0f548c;
  --color-brand-bg-pressed:   #0c3b5e;
  --color-brand-bg-selected:  #0e4775;
  --color-brand-fg-1:         #2899f5;
  --color-brand-fg-2:         #4cc2ff;
  --color-brand-fg-light:     #62cfff;
  --color-brand-stroke:       #2899f5;
  --color-compound-brand:     #2899f5;
  --color-brand-bg-light-alpha: rgba(40, 153, 245, 0.12);

  /* ---- Status ---- */
  --color-status-danger:      #d13438;
  --color-status-danger-fg:   #ff99a4;
  --color-status-success:     #5ec775;
  --color-status-warning:     #ffc83d;

  /* ---- Spectrum ---- */
  --spec-line:                #4cc2ff;
  --spec-fill:                rgba(76, 194, 255, 0.15);
  --spec-peak:                rgba(255, 200, 61, 0.85);
  --vfo-stroke:               #2899f5;
  --vfo-fill:                 rgba(40, 153, 245, 0.16);

  /* ---- Radii (Fluent 2) ---- */
  --radius-none:    0;
  --radius-sm:      2px;
  --radius-md:      4px;
  --radius-lg:      6px;
  --radius-xl:      8px;
  --radius-circ:    9999px;

  /* ---- Spacing (4-8-12-16-20-24-32 grid) ---- */
  --sp-xxs: 2px;
  --sp-xs:  4px;
  --sp-sn:  6px;
  --sp-s:   8px;
  --sp-mn:  10px;
  --sp-m:   12px;
  --sp-l:   16px;
  --sp-xl:  20px;
  --sp-xxl: 24px;

  /* ---- Typography (Segoe UI Variable, fall back to system) ---- */
  --font-base:
      'Segoe UI Variable Display','Segoe UI Variable','Segoe UI',
      -apple-system, BlinkMacSystemFont,'Helvetica Neue', Arial,
      system-ui, sans-serif;
  --font-mono:
      'Cascadia Code','Cascadia Mono','Consolas','JetBrains Mono','SF Mono',
      ui-monospace,'Menlo', monospace;

  --fs-200: 12px;
  --fs-300: 14px;
  --fs-400: 16px;
  --fs-500: 20px;
  --fs-600: 24px;
  --fs-700: 28px;
  --fs-800: 32px;

  --fw-regular:  400;
  --fw-medium:   500;
  --fw-semibold: 600;
  --fw-bold:     700;

  --shadow-2:  0 1px 2px rgba(0,0,0,0.28), 0 0 2px rgba(0,0,0,0.20);
  --shadow-4:  0 2px 4px rgba(0,0,0,0.28), 0 0 2px rgba(0,0,0,0.20);
  --shadow-8:  0 4px 8px rgba(0,0,0,0.32), 0 0 2px rgba(0,0,0,0.22);
  --shadow-16: 0 8px 16px rgba(0,0,0,0.36), 0 0 2px rgba(0,0,0,0.22);

  --curve-fast:    150ms cubic-bezier(0.33, 0.0, 0.67, 1.0);
  --curve-decel:   200ms cubic-bezier(0.10, 0.90, 0.20, 1.00);

  --drawer-width: 360px;
  --spec-pct: 30%;          /* spectrum % of canvas-wrap (set by splitter) */
}

/* ---------------------------------------------------------- Reset / base */
*, *::before, *::after { box-sizing: border-box; }
html, body {
  height: 100%;
  margin: 0;
  background: var(--color-bg-1);
  color: var(--color-fg-1);
  font-family: var(--font-base);
  font-size: var(--fs-300);
  line-height: 1.4;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  text-rendering: optimizeLegibility;
  overflow: hidden;          /* viewport-filling app */
}
body {
  display: grid;
  grid-template-rows: auto 1fr auto;
  background:
    radial-gradient(120% 50% at 50% -20%,
                    rgba(40,153,245,0.04) 0%,
                    transparent 60%),
    var(--color-bg-1);
}
::selection { background: var(--color-brand-bg); color: var(--color-fg-1); }

:focus-visible { outline: 2px solid var(--color-compound-brand); outline-offset: 2px; }

/* ============================================================ APP BAR */
.appbar {
  display: grid;
  grid-template-columns: auto 1fr auto;
  align-items: center;
  gap: var(--sp-l);
  padding: var(--sp-s) var(--sp-l);
  background: var(--color-bg-2);
  border-bottom: 1px solid var(--color-stroke-divider);
  min-height: 52px;
}
.brand {
  display: flex; align-items: center; gap: var(--sp-s);
  font-size: var(--fs-400);
  letter-spacing: -0.1px;
  color: var(--color-fg-1);
  white-space: nowrap;
  min-width: 0;
}
.brand-title { font-weight: var(--fw-semibold); }
.brand-accent { color: var(--color-brand-fg-1); margin: 0 1px; }

/* SDRweb logo: signal-tower mark + wordmark. Hidden via [hidden] when the
   user disables it in Settings. */
.brand-logo {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 3px 8px 3px 6px;
  border-radius: 6px;
  background: linear-gradient(180deg,
    rgba(40,153,245,0.10), rgba(40,153,245,0.04));
  border: 1px solid rgba(40,153,245,0.22);
  line-height: 1;
}
.brand-logo[hidden] { display: none; }
.brand-mark {
  color: var(--color-brand-fg-1);
  flex: 0 0 auto;
}
.brand-wordmark {
  font-weight: var(--fw-semibold);
  font-size: var(--fs-400);
  letter-spacing: 0.2px;
  color: var(--color-fg-1);
}
.brand-wordmark .brand-web {
  font-weight: var(--fw-regular);
  color: var(--color-fg-2);
}
.brand-sep {
  color: var(--color-fg-disabled);
  font-weight: var(--fw-regular);
}
.brand-sep[hidden] { display: none; }
.brand-device {
  font-weight: var(--fw-semibold);
  color: var(--color-fg-1);
  overflow: hidden;
  text-overflow: ellipsis;
  min-width: 0;
}
.brand-device:empty { display: none; }

.dot {
  width: 8px; height: 8px;
  border-radius: 50%;
  background: var(--color-status-danger);
  box-shadow: 0 0 6px currentColor;
  transition: background-color var(--curve-fast);
}
.dot.connected { background: var(--color-status-success); }
.dot.connected.rtl-down { background: var(--color-status-warning); }

/* ---- frequency display ---- */
.freq-area {
  position: relative;
  justify-self: center;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 2px;
  min-width: 0;
}
.freq-sub {
  display: flex;
  align-items: baseline;
  gap: var(--sp-xs);
  font-family: var(--font-mono);
  font-size: var(--fs-200);
  color: var(--color-fg-3);
  letter-spacing: 0.4px;
  user-select: none;
  line-height: 1;
}
.freq-sub-item { white-space: nowrap; }
.freq-sub-sep { color: var(--color-fg-disabled); }

.rds-line {
  display: flex;
  align-items: center;
  gap: var(--sp-xs);
  margin-top: 2px;
  font-family: var(--font-mono);
  font-size: var(--fs-200);
  color: var(--color-brand-fg-1);
  letter-spacing: 0.4px;
  user-select: none;
  line-height: 1;
  max-width: min(60vw, 540px);
  min-height: 1em;
}
.rds-line[hidden] { display: none; }
.rds-tag {
  font-size: 9px;
  font-weight: var(--fw-semibold);
  letter-spacing: 1px;
  padding: 2px 5px;
  border-radius: 3px;
  background: rgba(40,153,245,0.18);
  color: var(--color-brand-fg-2);
  text-transform: uppercase;
  flex: 0 0 auto;
}
.rds-text {
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
  transition: opacity 220ms ease;
  min-width: 0;
}
.rds-text.fade { opacity: 0; }
.freq-display {
  display: flex; align-items: baseline;
  font-family: var(--font-mono);
  font-size: clamp(26px, 3.8vw, 44px);
  font-weight: var(--fw-semibold);
  letter-spacing: 0;
  color: var(--color-fg-1);
  user-select: none;
  cursor: text;
  outline: none;
  line-height: 1.05;
}
.freq-display:focus-visible { outline: none; }
@keyframes freq-flash {
  0%   { color: var(--color-brand-fg-2); text-shadow: 0 0 12px rgba(40,153,245,0.65); }
  100% { color: var(--color-fg-1);       text-shadow: none; }
}
.freq-display.flash { animation: freq-flash 700ms ease-out; }

.freq-display .digit {
  display: inline-block;
  min-width: 0.7em;
  padding: 0 0.04em;
  text-align: center;
  position: relative;
  cursor: ns-resize;
  border-radius: 2px;
  transition: color var(--curve-fast), background-color var(--curve-fast);
}
.freq-display .digit:hover { color: var(--color-brand-fg-2); }
.freq-display .digit.dim { color: var(--color-fg-disabled); }
.freq-display .digit.dim:hover { color: var(--color-brand-fg-2); }
.freq-display .sep.dim { color: var(--color-fg-disabled); }
.freq-display .digit.focused {
  color: var(--color-brand-fg-2);
  background: rgba(40,153,245,0.18);
  box-shadow: inset 0 -2px 0 var(--color-brand-fg-1);
}
.freq-display .digit.focused.dim { color: var(--color-brand-fg-2); }
.freq-display .sep {
  display: inline-block;
  min-width: 0.32em;
  padding: 0 0.06em;
  text-align: center;
  color: var(--color-fg-3);
  font-weight: var(--fw-regular);
  user-select: none;
}
.freq-display .unit {
  margin-left: var(--sp-mn);
  font-size: 0.42em;
  font-weight: var(--fw-medium);
  color: var(--color-fg-3);
  letter-spacing: 1.5px;
  text-transform: uppercase;
}

.appbar-meta {
  display: flex;
  flex-direction: column;
  align-items: flex-end;
  gap: var(--sp-xs);
  min-width: 0;
}
.meta-row { display: flex; gap: var(--sp-s); align-items: center; }
.meta-row.sub {
  font-size: var(--fs-200);
  color: var(--color-fg-3);
  font-family: var(--font-mono);
}

.chip {
  font-size: var(--fs-200);
  font-weight: var(--fw-semibold);
  padding: 2px var(--sp-s);
  border-radius: var(--radius-md);
  background: var(--color-brand-bg-light-alpha);
  color: var(--color-brand-fg-2);
  letter-spacing: 0.2px;
  text-transform: uppercase;
}

.band-preset {
  font-size: var(--fs-200);
  max-width: 220px;
}

/* ============================================================ WORKSPACE */
.workspace {
  display: grid;
  grid-template-columns: 1fr 6px var(--drawer-width);
  min-height: 0;
  background: var(--color-bg-1);
}
.workspace.drawer-collapsed {
  grid-template-columns: 1fr 0 0;
}

/* ---- Vertical splitter (between canvas + drawer) ---- */
.vsplitter {
  background: var(--color-bg-2);
  border-left: 1px solid var(--color-stroke-divider);
  border-right: 1px solid var(--color-stroke-divider);
  cursor: ew-resize;
  position: relative;
  outline: none;
}
.vsplitter::before {
  content: "";
  position: absolute;
  top: 50%; left: 50%;
  transform: translate(-50%, -50%);
  width: 2px; height: 36px;
  border-radius: 1px;
  background: var(--color-stroke-1);
  opacity: 0.6;
}
.vsplitter:hover::before { opacity: 1; background: var(--color-brand-fg-1); }
.workspace.drawer-collapsed .vsplitter { display: none; }

/* ============================================================ CANVAS WRAP */
.canvas-wrap {
  position: relative;
  display: grid;
  grid-template-rows: var(--spec-pct) 6px 1fr;
  background: var(--color-bg-3);
  overflow: hidden;
  min-height: 0;
  /* Stop click+drag on the spectrum from accidentally selecting page text. */
  user-select: none;
  -webkit-user-select: none;
  -webkit-touch-callout: none;
}
.canvas-wrap canvas { display: block; width: 100%; height: 100%; }

#spectrum {
  background: linear-gradient(180deg, #0e0e0e 0%, #080808 100%);
  cursor: crosshair;
}
#waterfall {
  background: #050505;
  cursor: crosshair;
}

/* horizontal splitter between spectrum/waterfall */
.hsplitter {
  background: var(--color-bg-2);
  border-top: 1px solid var(--color-stroke-divider);
  border-bottom: 1px solid var(--color-stroke-divider);
  cursor: ns-resize;
  position: relative;
  outline: none;
}
.hsplitter::before {
  content: "";
  position: absolute;
  top: 50%; left: 50%;
  transform: translate(-50%, -50%);
  width: 36px; height: 2px;
  border-radius: 1px;
  background: var(--color-stroke-1);
  opacity: 0.6;
}
.hsplitter:hover::before { opacity: 1; background: var(--color-brand-fg-1); }

/* VFO marker overlay */
.vfo-overlay {
  position: absolute;
  top: 0; bottom: 0;
  pointer-events: none;
  border-left: 1.5px solid var(--vfo-stroke);
  border-right: 1.5px solid var(--vfo-stroke);
  background: var(--vfo-fill);
  transition: left 80ms linear, width 80ms linear;
  display: none;
  z-index: 2;
}
.vfo-overlay.visible { display: block; }
.vfo-label {
  position: absolute;
  bottom: calc(100% - 2px);
  left: 50%;
  transform: translateX(-50%);
  background: var(--vfo-stroke);
  color: var(--color-fg-1);
  font-family: var(--font-mono);
  font-size: var(--fs-200);
  font-weight: var(--fw-semibold);
  padding: 2px var(--sp-s);
  border-radius: var(--radius-md) var(--radius-md) 0 0;
  white-space: nowrap;
  letter-spacing: 0.5px;
  pointer-events: none;
}
/* Draggable cap on top of the VFO marker — sits above the spectrum,
   re-enables pointer events that the overlay otherwise disables. The
   marker box's min-width is matched to this width in waterfall.js so the
   handle never visually overhangs the box. */
.vfo-handle {
  position: absolute;
  top: 0;
  left: 50%;
  transform: translateX(-50%);
  width: 22px;
  height: 12px;
  background: var(--vfo-stroke);
  border-radius: 0 0 var(--radius-sm) var(--radius-sm);
  /* Visual cue only — actual drag is hit-tested on the canvas below so we
     don't fight pointer-events: none inheritance from .vfo-overlay. */
  pointer-events: none;
  z-index: 4;
  transition: background var(--curve-fast), height 80ms ease-out;
}
.vfo-handle::after {
  content: "";
  position: absolute;
  top: 3px; left: 50%;
  transform: translateX(-50%);
  width: 10px; height: 2px;
  background: var(--color-fg-1);
  border-radius: 1px;
  box-shadow: 0 3px 0 var(--color-fg-1);
}
.vfo-handle:hover, .vfo-handle.active {
  background: var(--color-brand-fg-2);
  height: 14px;
}

/* S-meter floats over the canvases at top-right */
.s-meter {
  position: absolute;
  top: var(--sp-s);
  right: var(--sp-s);
  display: flex;
  align-items: center;
  gap: var(--sp-s);
  background: rgba(15, 15, 17, 0.94);
  backdrop-filter: blur(6px);
  -webkit-backdrop-filter: blur(6px);
  border: 1px solid rgba(40, 153, 245, 0.35);
  border-radius: var(--radius-md);
  padding: var(--sp-xs) var(--sp-s);
  font-family: var(--font-mono);
  font-size: var(--fs-200);
  font-weight: var(--fw-medium);
  color: var(--color-fg-1);
  pointer-events: none;
  z-index: 3;
  min-width: 140px;
  box-shadow: var(--shadow-8);
}
.s-meter-bar {
  flex: 1;
  height: 6px;
  background: var(--color-bg-3);
  border-radius: var(--radius-circ);
  position: relative;
  overflow: hidden;
}
.s-meter-bar::after {
  content: "";
  position: absolute;
  top: 0; left: 0; bottom: 0;
  width: var(--meter-pct, 0%);
  background: linear-gradient(90deg,
    var(--color-status-success) 0%,
    var(--color-status-warning) 65%,
    var(--color-status-danger) 100%);
  transition: width 100ms linear;
}
.s-meter-text { white-space: nowrap; min-width: 60px; text-align: right; }

/* Move the S-meter and cursor readout to sit just above the band-marker
   strip (bottom of the spectrum area, not the bottom of the whole canvas).
   --spec-pct is the spectrum row height; the +38px clears the 30px band
   strip plus a little breathing room. */
.canvas-wrap.overlays-bottom .s-meter,
.canvas-wrap.overlays-bottom .cursor-readout {
  top: auto;
  bottom: calc(100% - var(--spec-pct) + 38px);
}

.cursor-readout {
  position: absolute;
  top: var(--sp-s); left: var(--sp-s);
  background: rgba(20,20,20,0.85);
  border: 1px solid var(--color-stroke-subtle);
  border-radius: var(--radius-md);
  padding: var(--sp-xs) var(--sp-mn);
  font-family: var(--font-mono);
  font-size: var(--fs-200);
  color: var(--color-fg-2);
  pointer-events: none;
  display: none;
  z-index: 3;
  box-shadow: var(--shadow-4);
}
.cursor-readout.visible { display: block; }

.overlay-controls {
  position: absolute;
  bottom: var(--sp-s); left: var(--sp-s);
  display: flex;
  gap: var(--sp-xs);
  z-index: 3;
}

/* ============================================================ PANELS / CARDS */
.panels-drawer {
  background: var(--color-bg-2);
  overflow-y: auto;
  overflow-x: hidden;
  display: flex;
  flex-direction: column;
  gap: var(--sp-m);
  padding: var(--sp-m);
  min-width: 0;
  scrollbar-gutter: stable;
}
.workspace.drawer-collapsed .panels-drawer {
  display: none;
}

.panel {
  background: var(--color-bg-card);
  border: 1px solid var(--color-stroke-subtle);
  border-radius: var(--radius-xl);
  padding: var(--sp-m) var(--sp-l);
  display: flex;
  flex-direction: column;
  gap: var(--sp-mn);
}
.panel h3 {
  margin: 0 0 var(--sp-xs) 0;
  font-size: var(--fs-200);
  font-weight: var(--fw-semibold);
  letter-spacing: 0.6px;
  text-transform: uppercase;
  color: var(--color-fg-3);
}
.panel h4.subhead {
  margin: var(--sp-s) 0 var(--sp-xs) 0;
  font-size: var(--fs-100);
  font-weight: var(--fw-semibold);
  letter-spacing: 0.5px;
  text-transform: uppercase;
  color: var(--color-fg-2);
  border-bottom: 1px solid var(--color-stroke-divider);
  padding-bottom: 4px;
}
.panel h4.subhead:first-child { margin-top: 0; }

.row { display: flex; flex-direction: column; gap: var(--sp-xs); }
.row label {
  font-size: var(--fs-200);
  color: var(--color-fg-2);
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  font-weight: var(--fw-regular);
}
.row .value {
  font-family: var(--font-mono);
  font-size: var(--fs-200);
  color: var(--color-fg-1);
  font-weight: var(--fw-medium);
}
.row.toggle-row { flex-direction: row; gap: var(--sp-l); flex-wrap: wrap; }
.row.btn-row { flex-direction: row; gap: var(--sp-s); flex-wrap: wrap; }

/* ============================================================ INPUTS */
input[type="range"] {
  -webkit-appearance: none;
  appearance: none;
  width: 100%;
  height: 28px;
  background: transparent;
  outline: none;
  margin: 0;
  cursor: pointer;
}
input[type="range"]::-webkit-slider-runnable-track {
  height: 4px; background: var(--color-stroke-1); border-radius: var(--radius-circ);
}
input[type="range"]::-moz-range-track {
  height: 4px; background: var(--color-stroke-1); border-radius: var(--radius-circ);
}
input[type="range"]::-webkit-slider-thumb {
  -webkit-appearance: none; appearance: none;
  width: 16px; height: 16px;
  margin-top: -6px;
  background: var(--color-fg-1);
  border-radius: 50%;
  border: 4px solid var(--color-compound-brand);
  box-sizing: border-box;
  transition: border-color var(--curve-fast), transform 80ms ease;
}
input[type="range"]::-moz-range-thumb {
  width: 8px; height: 8px;
  background: var(--color-fg-1);
  border-radius: 50%;
  border: 4px solid var(--color-compound-brand);
  box-sizing: border-box;
}
input[type="range"]:hover::-webkit-slider-thumb {
  border-color: var(--color-brand-fg-2);
  transform: scale(1.05);
}
input[type="range"]:disabled { opacity: 0.5; cursor: not-allowed; }

input[type="checkbox"] {
  -webkit-appearance: none; appearance: none;
  width: 40px; height: 20px;
  background: transparent;
  border: 1px solid var(--color-stroke-accessible);
  border-radius: var(--radius-circ);
  position: relative;
  cursor: pointer;
  transition: background var(--curve-fast), border-color var(--curve-fast);
  vertical-align: middle;
  margin-right: var(--sp-s);
  flex-shrink: 0;
}
input[type="checkbox"]::after {
  content: "";
  position: absolute;
  top: 50%; left: 4px;
  width: 12px; height: 12px;
  margin-top: -6px;
  border-radius: 50%;
  background: var(--color-fg-2);
  transition: left var(--curve-decel), background var(--curve-fast);
}
input[type="checkbox"]:hover { border-color: var(--color-fg-1); }
input[type="checkbox"]:checked {
  background: var(--color-brand-bg);
  border-color: var(--color-brand-bg);
}
input[type="checkbox"]:checked::after {
  left: 22px;
  background: var(--color-fg-1);
}

.toggle {
  display: inline-flex; align-items: center; cursor: pointer; user-select: none;
  font-size: var(--fs-300);
  color: var(--color-fg-1);
}

select {
  background: var(--color-bg-1);
  color: var(--color-fg-1);
  border: 1px solid var(--color-stroke-1);
  border-bottom: 1px solid var(--color-stroke-accessible);
  border-radius: var(--radius-md);
  padding: 6px var(--sp-m);
  padding-right: 28px;
  font-family: var(--font-base);
  font-size: var(--fs-300);
  outline: none;
  cursor: pointer;
  appearance: none;
  background-image:
    url("data:image/svg+xml;utf8,<svg xmlns='http://www.w3.org/2000/svg' width='12' height='12' viewBox='0 0 12 12'><path fill='%23d6d6d6' d='M2.5 4.5l3.5 3.5 3.5-3.5z'/></svg>");
  background-repeat: no-repeat;
  background-position: right 8px center;
  transition: border-color var(--curve-fast), background-color var(--curve-fast);
}
select:hover {
  background-color: var(--color-bg-1-hover);
  border-color: var(--color-stroke-accessible);
}
select:focus-visible { border-color: var(--color-compound-brand); }

/* ---- Buttons ---- */
button.btn {
  appearance: none;
  border: 1px solid var(--color-stroke-1);
  border-bottom: 1px solid var(--color-stroke-accessible);
  background: var(--color-bg-1);
  color: var(--color-fg-1);
  font-family: var(--font-base);
  font-size: var(--fs-300);
  font-weight: var(--fw-semibold);
  padding: 5px var(--sp-m);
  border-radius: var(--radius-md);
  cursor: pointer;
  transition: background var(--curve-fast), border-color var(--curve-fast);
  min-height: 32px;
  display: inline-flex; align-items: center; justify-content: center; gap: 6px;
  white-space: nowrap;
}
button.btn:hover {
  background: var(--color-bg-1-hover);
  border-color: var(--color-stroke-accessible);
}
button.btn:active { background: var(--color-bg-1-pressed); }
button.btn:disabled { opacity: 0.5; cursor: not-allowed; }
button.btn.small { min-height: 24px; padding: 2px var(--sp-s); font-size: var(--fs-200); }

button.btn.primary {
  background: var(--color-brand-bg);
  color: var(--color-fg-1);
  border-color: var(--color-brand-bg);
}
button.btn.primary:hover {
  background: var(--color-brand-bg-hover);
  border-color: var(--color-brand-bg-hover);
}
button.btn.primary:active {
  background: var(--color-brand-bg-pressed);
  border-color: var(--color-brand-bg-pressed);
}
button.btn.danger {
  background: var(--color-status-danger);
  color: var(--color-fg-1);
  border-color: var(--color-status-danger);
}

button.btn.ghost {
  background: rgba(0,0,0,0);
  border-color: transparent;
  color: var(--color-fg-2);
}
button.btn.ghost:hover {
  background: var(--color-subtle-hover);
  color: var(--color-fg-1);
}

button.icon-btn {
  padding: 0;
  width: 36px;
  height: 36px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
}
button.icon-btn svg { width: 18px; height: 18px; }
button.btn.small.icon-btn {
  width: 32px;
  height: 32px;
  min-height: 32px;
}
button.btn.small.icon-btn svg { width: 18px; height: 18px; }

/* ---- Segmented / mode picker ---- */
.seg {
  display: flex;
  flex-wrap: wrap;
  gap: var(--sp-xs);
  background: var(--color-bg-1);
  border: 1px solid var(--color-stroke-subtle);
  border-radius: var(--radius-md);
  padding: var(--sp-xs);
}
.seg button {
  appearance: none;
  border: none;
  background: transparent;
  color: var(--color-fg-2);
  font-family: var(--font-base);
  font-size: var(--fs-200);
  font-weight: var(--fw-semibold);
  padding: 4px var(--sp-mn);
  border-radius: var(--radius-sm);
  cursor: pointer;
  letter-spacing: 0.2px;
  transition: background var(--curve-fast), color var(--curve-fast);
  min-height: 24px;
  flex: 1 0 auto;
}
.seg button:hover {
  background: var(--color-subtle-hover);
  color: var(--color-fg-1);
}
.seg button.active {
  background: var(--color-brand-bg);
  color: var(--color-fg-1);
  box-shadow: 0 0 0 1px var(--color-brand-fg-1) inset,
              0 1px 0 var(--color-brand-fg-1);
  text-shadow: 0 0 8px rgba(76, 194, 255, 0.4);
}
.seg button.active:hover { background: var(--color-brand-bg-hover); }

/* ---- Bookmarks ---- */
.bookmarks {
  display: flex;
  flex-direction: column;
  gap: 2px;
  max-height: 240px;
  overflow-y: auto;
  margin: 0 calc(-1 * var(--sp-xs));
}
.bookmark {
  display: grid;
  grid-template-columns: 1fr auto auto;
  grid-template-areas:
    "name freq del"
    "name mode del";
  column-gap: var(--sp-s);
  row-gap: 1px;
  align-items: center;
  padding: 6px var(--sp-mn);
  border-radius: var(--radius-md);
  background: transparent;
  border: 1px solid transparent;
  font-size: var(--fs-200);
  transition: background var(--curve-fast), border-color var(--curve-fast);
}
.bookmark:hover {
  background: var(--color-subtle-hover);
  border-color: var(--color-stroke-subtle);
}
.bookmark .bm-name {
  grid-area: name;
  min-width: 0;
  background: transparent;
  border: 1px solid transparent;
  border-radius: var(--radius-sm);
  padding: 3px 6px;
  color: var(--color-fg-1);
  font-family: var(--font-base);
  font-size: var(--fs-300);
  font-weight: var(--fw-medium);
  outline: none;
  transition: border-color var(--curve-fast), background var(--curve-fast);
}
.bookmark .bm-name::placeholder { color: var(--color-fg-disabled); font-style: italic; }
.bookmark .bm-name:hover { border-color: var(--color-stroke-subtle); }
.bookmark .bm-name:focus {
  border-color: var(--color-compound-brand);
  background: var(--color-bg-1);
}
.bookmark .bm-freq {
  grid-area: freq;
  font-family: var(--font-mono);
  color: var(--color-fg-2);
  font-size: var(--fs-200);
  text-align: right;
  cursor: pointer;
}
.bookmark .bm-mode {
  grid-area: mode;
  color: var(--color-fg-3);
  font-size: var(--fs-100);
  text-align: right;
  letter-spacing: 0.3px;
  cursor: pointer;
}
.bookmark .bm-freq:hover, .bookmark .bm-mode:hover { color: var(--color-brand-fg-2); }
.bookmark .del {
  grid-area: del;
  background: transparent; border: none;
  color: var(--color-fg-3); cursor: pointer;
  padding: 2px var(--sp-s);
  border-radius: var(--radius-md);
  font-size: var(--fs-300);
  line-height: 1;
  align-self: center;
}
.bookmark .del:hover {
  color: var(--color-status-danger-fg);
  background: rgba(209,52,56,0.10);
}

/* Scrollbars */
.bookmarks::-webkit-scrollbar,
.panels-drawer::-webkit-scrollbar { width: 8px; height: 8px; }
.bookmarks::-webkit-scrollbar-track,
.panels-drawer::-webkit-scrollbar-track { background: transparent; }
.bookmarks::-webkit-scrollbar-thumb,
.panels-drawer::-webkit-scrollbar-thumb {
  background: var(--color-stroke-subtle);
  border-radius: var(--radius-circ);
}
.bookmarks::-webkit-scrollbar-thumb:hover,
.panels-drawer::-webkit-scrollbar-thumb:hover { background: var(--color-stroke-1); }

/* ============================================================ STATUS BAR */
.statusbar {
  display: flex;
  gap: var(--sp-xl);
  padding: var(--sp-s) var(--sp-l);
  background: var(--color-bg-2);
  border-top: 1px solid var(--color-stroke-divider);
  font-family: var(--font-mono);
  font-size: var(--fs-200);
  color: var(--color-fg-3);
  align-items: center;
  min-height: 28px;
}
.statusbar .grow { flex: 1; }
.statusbar .muted { color: var(--color-fg-4); }
.status-users {
  display: inline-flex;
  align-items: center;
  gap: 5px;
  padding: 2px 8px;
  border-radius: 999px;
  background: rgba(40,153,245,0.10);
  border: 1px solid rgba(40,153,245,0.28);
  color: var(--color-brand-fg-2);
  font-variant-numeric: tabular-nums;
}
.status-users.solo {
  background: transparent;
  border-color: var(--color-stroke-subtle);
  color: var(--color-fg-3);
}
.status-users svg { flex: 0 0 auto; }
#status-users-count { font-weight: var(--fw-semibold); }
.statusbar .hint-keys { display: inline-flex; gap: 4px; align-items: center; }
.statusbar .hint-keys kbd {
  font-family: var(--font-mono);
  font-size: 10px;
  background: var(--color-bg-card);
  color: var(--color-fg-2);
  border: 1px solid var(--color-stroke-subtle);
  border-radius: var(--radius-sm);
  padding: 0 4px;
  margin: 0 2px;
}
@media (max-width: 900px) { .statusbar .hint-keys { display: none; } }

/* ============================================================ RESPONSIVE */
@media (max-width: 900px) {
  :root { --drawer-width: 280px; }
  .appbar {
    grid-template-columns: 1fr auto;
    grid-template-rows: auto auto;
    gap: var(--sp-s);
    padding: var(--sp-s) var(--sp-mn);
  }
  .freq-area {
    grid-column: 1 / -1;
    justify-self: stretch;
  }
  .freq-display { font-size: clamp(22px, 7vw, 32px); }
}

/* Mobile-only drawer chrome — defined here so it stays display:none on
   desktop without needing a media query above the breakpoint. */
.drawer-backdrop { display: none; }
.panels-drawer-mobile-head { display: none; }

@media (max-width: 640px) {
  /* Spectrum gets the full width; the drawer becomes an overlay. */
  .workspace {
    grid-template-columns: 1fr 0 0;
  }
  .vsplitter, .panels-drawer { display: none; }

  /* Keep the appbar + statusbar above any drawer overlay so the user can
     always see — and tap — the hamburger to dismiss. */
  .appbar    { position: relative; z-index: 60; }
  .statusbar { position: relative; z-index: 60; }

  /* When the drawer is open: dim backdrop + slide-in panel from the right. */
  .workspace.mobile-drawer-open .drawer-backdrop {
    display: block;
    position: fixed;
    inset: 0;
    background: rgba(0, 0, 0, 0.55);
    z-index: 50;
    animation: backdrop-in 160ms ease-out;
  }
  .workspace.mobile-drawer-open .panels-drawer {
    display: flex;
    position: fixed;
    top: 0; right: 0; bottom: 0;
    width: 88vw;
    max-width: 320px;
    z-index: 55;
    overflow-y: auto;
    box-shadow: -8px 0 24px rgba(0, 0, 0, 0.55);
    padding-top: env(safe-area-inset-top);
    padding-bottom: env(safe-area-inset-bottom);
    -webkit-overflow-scrolling: touch;
    animation: drawer-slide-in 200ms cubic-bezier(.2,.8,.2,1);
  }
  /* Sticky header inside the drawer with a close X — gives users a clear
     dismissal affordance even if they don't realise the backdrop is tappable. */
  .panels-drawer-mobile-head {
    display: flex;
    align-items: center; justify-content: space-between;
    position: sticky; top: 0;
    background: var(--color-bg-1);
    border-bottom: 1px solid var(--color-stroke-divider);
    padding: 8px 12px;
    z-index: 1;
    font-size: var(--fs-300);
    color: var(--color-fg-2);
    font-weight: 600;
  }
}

@keyframes drawer-slide-in {
  from { transform: translateX(100%); }
  to   { transform: translateX(0); }
}
@keyframes backdrop-in {
  from { opacity: 0; }
  to   { opacity: 1; }
}

/* ---- toast stack ---- */
.toast-stack {
  position: fixed;
  bottom: 56px;
  left: 50%;
  transform: translateX(-50%);
  display: flex;
  flex-direction: column;
  gap: var(--sp-xs);
  z-index: 200;
  pointer-events: none;
}
.toast {
  background: rgba(20, 20, 22, 0.96);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  border: 1px solid var(--color-stroke-divider);
  border-left: 3px solid var(--color-brand-fg-1);
  border-radius: var(--radius-md);
  padding: 8px 14px;
  color: var(--color-fg-1);
  font-size: var(--fs-200);
  font-weight: var(--fw-medium);
  box-shadow: var(--shadow-16);
  min-width: 220px;
  max-width: 360px;
  pointer-events: auto;
  animation: toast-in 180ms cubic-bezier(.2,.8,.2,1);
}
.toast.warn { border-left-color: var(--color-status-warning); }
.toast.err  { border-left-color: var(--color-status-danger); }
.toast.ok   { border-left-color: var(--color-status-success); }
.toast.dismiss { animation: toast-out 200ms ease-in forwards; }
@keyframes toast-in {
  from { opacity: 0; transform: translateY(8px); }
  to   { opacity: 1; transform: translateY(0); }
}
@keyframes toast-out {
  to { opacity: 0; transform: translateY(8px); }
}

/* ---- settings modal ---- */
.modal-backdrop {
  position: fixed; inset: 0;
  background: rgba(0, 0, 0, 0.55);
  display: flex; align-items: center; justify-content: center;
  z-index: 100;
  padding: var(--sp-l);
}
.modal-backdrop[hidden] { display: none; }
.modal {
  background: var(--color-bg-card);
  border: 1px solid var(--color-stroke-divider);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-28);
  width: min(440px, 100%);
  max-height: calc(100vh - 2 * var(--sp-l));
  display: flex; flex-direction: column;
}
.modal-head {
  display: flex; align-items: center; justify-content: space-between;
  padding: var(--sp-mn) var(--sp-l);
  border-bottom: 1px solid var(--color-stroke-divider);
}
.modal-head h2 {
  margin: 0;
  font-size: var(--fs-400);
  font-weight: var(--fw-semibold);
  color: var(--color-fg-1);
}
.modal-body {
  padding: var(--sp-l);
  overflow-y: auto;
  display: flex; flex-direction: column; gap: var(--sp-l);
}
.modal-foot {
  display: flex; gap: var(--sp-s); justify-content: flex-end;
  padding: var(--sp-mn) var(--sp-l);
  border-top: 1px solid var(--color-stroke-divider);
}
.form-row { display: flex; flex-direction: column; gap: 6px; }
.form-row label {
  font-size: var(--fs-200);
  font-weight: var(--fw-medium);
  color: var(--color-fg-2);
  letter-spacing: 0.2px;
}
.form-row input {
  background: var(--color-bg-1);
  color: var(--color-fg-1);
  font-family: var(--font-sans);
  font-size: var(--fs-300);
  border: 1px solid var(--color-stroke-divider);
  border-radius: var(--radius-sm);
  padding: 8px 10px;
  outline: none;
  transition: border-color var(--curve-fast);
}
.form-row input:focus { border-color: var(--color-compound-brand); }
.form-hint {
  margin: 0;
  font-size: var(--fs-100);
  color: var(--color-fg-3);
}
.form-msg {
  margin: 0;
  padding: 8px 10px;
  border-radius: var(--radius-sm);
  font-size: var(--fs-200);
}
.form-msg.ok    { background: rgba(76, 200, 130, 0.1); color: #58d68d; }
.form-msg.err   { background: rgba(232, 91, 91, 0.12); color: #ff8585; }

/* ---- bands editor ---- */
.modal.modal-wide { width: min(680px, 100%); }
.bands-table-head, .bands-row {
  display: grid;
  grid-template-columns: 1.4fr 1fr 0.8fr 0.8fr 1fr 1fr 44px 28px;
  gap: var(--sp-xs);
  align-items: center;
}
.bands-row input[type="color"] {
  width: 100%;
  height: 28px;
  padding: 2px;
  background: var(--color-bg-1);
  border: 1px solid var(--color-stroke-divider);
  border-radius: var(--radius-sm);
  cursor: pointer;
}
.bands-table-head {
  font-size: var(--fs-100);
  font-weight: var(--fw-medium);
  color: var(--color-fg-3);
  letter-spacing: 0.4px;
  text-transform: uppercase;
  padding: 0 4px 4px 4px;
  border-bottom: 1px solid var(--color-stroke-divider);
}
.bands-list {
  display: flex; flex-direction: column;
  gap: 4px;
  max-height: 50vh;
  overflow-y: auto;
  padding-right: 4px;
}
.bands-row input, .bands-row select {
  background: var(--color-bg-1);
  color: var(--color-fg-1);
  font-family: var(--font-base);
  font-size: var(--fs-200);
  border: 1px solid var(--color-stroke-divider);
  border-radius: var(--radius-sm);
  padding: 6px 8px;
  outline: none;
  min-width: 0;
  width: 100%;
}
.bands-row input:focus, .bands-row select:focus { border-color: var(--color-compound-brand); }
.bands-row .freq-input { font-family: var(--font-mono); }
.bands-row .row-del {
  background: transparent; border: none;
  color: var(--color-fg-3); cursor: pointer;
  padding: 4px;
  border-radius: var(--radius-sm);
  font-size: var(--fs-300);
  line-height: 1;
}
.bands-row .row-del:hover {
  color: var(--color-status-danger-fg);
  background: rgba(209,52,56,0.10);
}
.modal-foot-extra {
  display: flex; justify-content: flex-end;
  margin-top: var(--sp-s);
}

/* ---- auth section in settings modal ---- */
.form-sep {
  border: none;
  border-top: 1px solid var(--color-stroke-divider);
  margin: var(--sp-m) 0 var(--sp-s) 0;
}
.form-section {
  font-size: var(--fs-300);
  color: var(--color-fg-2);
  margin: 0 0 var(--sp-xs) 0;
  font-weight: 600;
}
.users-list {
  list-style: none;
  margin: 0; padding: 0;
  display: flex; flex-direction: column; gap: 4px;
  max-height: 220px; overflow-y: auto;
  border: 1px solid var(--color-stroke-subtle);
  border-radius: var(--radius-sm);
  background: var(--color-bg-3);
}
.users-row {
  display: flex; align-items: center; justify-content: space-between;
  padding: 6px 10px;
  gap: var(--sp-s);
  border-bottom: 1px solid var(--color-stroke-divider);
}
.users-row:last-child { border-bottom: none; }
.users-name {
  font-family: var(--font-mono);
  color: var(--color-fg-1);
  word-break: break-all;
}
.users-actions {
  display: flex; gap: 6px;
}
.btn.ghost.small.danger {
  color: var(--color-status-danger-fg);
}
.btn.ghost.small.danger:hover {
  background: rgba(209,52,56,0.12);
}
.btn.ghost.small.inline {
  padding: 0 6px;
  margin-left: 6px;
  vertical-align: baseline;
}
.users-add-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 6px;
}
.users-add-grid > input,
.users-add-grid > select { min-width: 0; }
.users-add-grid input,
.users-add-grid select {
  padding: 6px 8px;
  background: var(--color-bg-3);
  border: 1px solid var(--color-stroke-subtle);
  border-radius: var(--radius-sm);
  color: var(--color-fg-1);
  font-size: var(--fs-300);
}
.users-add-grid input:focus,
.users-add-grid select:focus { border-color: var(--color-compound-brand); }
/* Row 2: role select on the left, Add button stretched on the right. */
#user-add-role { grid-column: 1; }
#user-add-btn  { grid-column: 2; justify-self: stretch; }
.users-role-select {
  background: var(--color-bg-3);
  border: 1px solid var(--color-stroke-subtle);
  border-radius: var(--radius-sm);
  color: var(--color-fg-1);
  font-size: var(--fs-200);
  padding: 3px 6px;
}
.role-chip {
  display: inline-block;
  font-size: var(--fs-100);
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.5px;
  padding: 2px 6px;
  border-radius: 999px;
  background: rgba(173,173,173,0.15);
  color: var(--color-fg-3);
}
.role-chip.admin {
  background: var(--color-brand-bg-light-alpha);
  color: var(--color-brand-fg-2);
}

/* ---- appbar user-menu (button + dropdown) ---- */
.user-menu-wrap {
  position: relative;
  display: inline-flex;
}
.user-menu-wrap[hidden] { display: none; }
.user-menu {
  position: absolute;
  top: calc(100% + 6px);
  right: 0;
  min-width: 200px;
  z-index: 50;
  background: var(--color-bg-1);
  border: 1px solid var(--color-stroke-subtle);
  border-radius: var(--radius-md);
  box-shadow: 0 8px 24px rgba(0,0,0,0.45);
  padding: 8px;
  display: flex; flex-direction: column; gap: 6px;
}
.user-menu[hidden] { display: none; }
.user-menu-head {
  display: flex; align-items: center; justify-content: space-between;
  gap: 8px;
  padding: 4px 6px 6px 6px;
  border-bottom: 1px solid var(--color-stroke-divider);
}
.user-menu-name {
  font-family: var(--font-mono);
  color: var(--color-fg-1);
  font-size: var(--fs-300);
  word-break: break-all;
}
.user-menu-item {
  display: flex; align-items: center; gap: 8px;
  background: transparent; border: none;
  color: var(--color-fg-2);
  text-align: left;
  padding: 6px 8px;
  border-radius: var(--radius-sm);
  cursor: pointer;
  font-size: var(--fs-300);
}
.user-menu-item:hover {
  background: var(--color-subtle-hover);
  color: var(--color-fg-1);
}

/* ---- /login page ---- */
.login-page {
  min-height: 100vh;
  display: flex; align-items: center; justify-content: center;
  background: var(--color-bg-2);
  margin: 0; padding: var(--sp-m);
}
.login-card {
  width: 100%; max-width: 360px;
  background: var(--color-bg-1);
  border: 1px solid var(--color-stroke-subtle);
  border-radius: var(--radius-md);
  padding: var(--sp-l);
  box-shadow: 0 8px 24px rgba(0,0,0,0.45);
}
.login-brand {
  display: flex; align-items: center; gap: 8px;
  color: var(--color-brand-fg-2);
  margin-bottom: var(--sp-s);
}
.login-brand .brand-wordmark {
  font-weight: 600; letter-spacing: 0.4px;
  font-size: var(--fs-400);
}
.login-title {
  margin: 0 0 var(--sp-m) 0;
  font-size: var(--fs-500);
  color: var(--color-fg-1);
  font-weight: 600;
}
.login-field {
  display: flex; flex-direction: column; gap: 4px;
  margin-bottom: var(--sp-s);
}
.login-field span {
  font-size: var(--fs-200);
  color: var(--color-fg-3);
}
.login-field input {
  padding: 8px 10px;
  background: var(--color-bg-3);
  border: 1px solid var(--color-stroke-subtle);
  border-radius: var(--radius-sm);
  color: var(--color-fg-1);
  font-size: var(--fs-300);
}
.login-field input:focus {
  border-color: var(--color-compound-brand);
  outline: none;
}
.login-submit {
  width: 100%;
  margin-top: var(--sp-s);
}
.login-msg {
  margin-top: var(--sp-s);
  padding: 8px 10px;
  border-radius: var(--radius-sm);
  font-size: var(--fs-200);
}
.login-msg.err {
  background: rgba(232, 91, 91, 0.12);
  color: #ff8585;
}

/* ============================================================ MOBILE POLISH */
/* Audio-quick button: keep it visually distinct from the ghost trio next to
   it so users on phones can find "play" at a glance. */
.overlay-controls .audio-quick.icon-btn {
  width: 32px; height: 32px;
  border-radius: 999px;
  padding: 0;
  display: inline-flex;
  align-items: center; justify-content: center;
}

@media (max-width: 640px) {
  /* iPhone notch / home indicator — keep chrome out of the unsafe regions. */
  .appbar    { padding-top:    calc(var(--sp-s) + env(safe-area-inset-top)); }
  .statusbar { padding-bottom: calc(var(--sp-xs) + env(safe-area-inset-bottom)); }

  /* Bigger hit targets for icon buttons (Apple HIG ≥44px; we settle for 36px
     to keep the dense top bar usable). */
  .icon-btn { min-width: 36px; min-height: 36px; }

  /* Settings + bands modals can overflow on tiny screens. Make them scroll. */
  .modal {
    max-height: calc(100vh - 24px);
    overflow-y: auto;
  }
  .modal-body { max-height: none; }

  /* Overlay controls already sit bottom-left; on mobile we want them tappable
     without overlapping the home-indicator gesture area. */
  .overlay-controls {
    bottom: calc(var(--sp-s) + env(safe-area-inset-bottom));
  }
}