:root {
  --bg0: #e8eef2;
  --bg1: #f7fafb;
  --ink: #14202b;
  --muted: #5a6b78;
  --line: #c5d0d8;
  --panel: rgba(255, 255, 255, 0.86);
  --accent: #0f6e6a;
  --accent-2: #c45c26;
  --canvas-bg: #0d151c;
  --shadow: 0 10px 30px rgba(20, 32, 43, 0.08);
  --font: "IBM Plex Sans KR", "Segoe UI", sans-serif;
  --mono: "IBM Plex Mono", ui-monospace, monospace;
}

* { box-sizing: border-box; }

html, body {
  margin: 0;
  min-height: 100%;
  color: var(--ink);
  font-family: var(--font);
  background:
    radial-gradient(1200px 600px at 10% -10%, #d7e7ea 0%, transparent 55%),
    radial-gradient(900px 500px at 100% 0%, #e7ddd2 0%, transparent 50%),
    linear-gradient(160deg, var(--bg0), var(--bg1));
}

body::before {
  content: "";
  position: fixed;
  inset: 0;
  pointer-events: none;
  opacity: 0.35;
  background-image:
    linear-gradient(rgba(20, 32, 43, 0.03) 1px, transparent 1px),
    linear-gradient(90deg, rgba(20, 32, 43, 0.03) 1px, transparent 1px);
  background-size: 28px 28px;
}

.app {
  max-width: 1500px;
  margin: 0 auto;
  padding: 1.1rem 1.2rem 2rem;
  position: relative;
  z-index: 1;
}

.topbar {
  display: flex;
  flex-wrap: wrap;
  gap: 1rem 2rem;
  align-items: flex-end;
  justify-content: space-between;
  margin-bottom: 1rem;
}

.topbar-right {
  display: flex;
  flex-direction: column;
  gap: 0.55rem;
  align-items: flex-end;
  max-width: 34rem;
}

.dataset-pick {
  display: flex;
  gap: 0.55rem;
  align-items: center;
  font-size: 0.85rem;
  color: var(--muted);
}

.dataset-pick select {
  min-width: 14rem;
  padding: 0.35rem 0.55rem;
  border: 1px solid var(--line);
  border-radius: 0.4rem;
  background: #fff;
  color: var(--ink);
  font-family: var(--font);
}

.brand {
  display: flex;
  gap: 0.85rem;
  align-items: center;
}

.brand-mark {
  display: grid;
  place-items: center;
  width: 3rem;
  height: 3rem;
  border-radius: 0.7rem;
  background: linear-gradient(145deg, #0f6e6a, #184a5a);
  color: #f4fbfa;
  font-family: var(--mono);
  font-weight: 500;
  letter-spacing: 0.04em;
  box-shadow: var(--shadow);
}

.brand h1 {
  margin: 0;
  font-size: 1.35rem;
  font-weight: 600;
  letter-spacing: -0.02em;
}

.subtitle, .hint-top, .help, .panel-meta, .status {
  color: var(--muted);
}

.subtitle {
  margin: 0.15rem 0 0;
  font-size: 0.92rem;
}

.hint-top {
  margin: 0;
  max-width: 34rem;
  font-size: 0.86rem;
  line-height: 1.45;
}

.workspace {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 320px;
  gap: 1rem;
  align-items: start;
}

.panels {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 0.9rem;
}

.panel {
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: 0.85rem;
  padding: 0.7rem;
  box-shadow: var(--shadow);
  backdrop-filter: blur(8px);
}

.panel-wide { grid-column: 1 / -1; }

.panel-head {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  flex-wrap: wrap;
  gap: 0.5rem 0.75rem;
  margin-bottom: 0.45rem;
}

.inline-select select {
  min-width: 9.5rem;
  padding: 0.2rem 0.35rem;
  border: 1px solid var(--line);
  border-radius: 0.35rem;
  background: #fff;
  color: var(--ink);
  font: inherit;
  font-size: 0.78rem;
}

.panel-head h2 {
  margin: 0;
  font-size: 0.98rem;
  font-weight: 600;
}

.panel-meta {
  font-family: var(--mono);
  font-size: 0.78rem;
}

.panel-hint {
  margin: 0.85rem 0 0.45rem;
  color: var(--muted);
  font-size: 0.78rem;
  line-height: 1.35;
}

#spec-canvas {
  cursor: crosshair;
}

canvas {
  display: block;
  border-radius: 0.45rem;
  background: var(--canvas-bg);
}

/* Bitmap already has physical aspect (desktop fit_to_cell). Never force 1:1 or max-height alone. */
.panel canvas#map-canvas,
.panel canvas#fft-canvas {
  width: auto;
  max-width: 100%;
  height: auto;
  margin-inline: auto;
}

.panel canvas#eq-canvas,
.panel canvas#ed-canvas,
.panel canvas#spec-canvas {
  width: 100%;
  height: auto;
}

.btn-row {
  display: flex;
  flex-wrap: wrap;
  gap: 0.35rem;
  margin: 0.35rem 0;
}

.tool-btn.active {
  border-color: var(--accent);
  color: var(--accent);
  background: #e7f4f3;
}

#map-canvas.probe-point {
  cursor: crosshair;
}

#map-canvas.probe-line {
  cursor: crosshair;
}

.controls {
  position: sticky;
  top: 0.75rem;
  max-height: calc(100vh - 1.5rem);
  overflow: auto;
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: 0.85rem;
  padding: 0.85rem 0.9rem 1.1rem;
  box-shadow: var(--shadow);
  backdrop-filter: blur(8px);
}

.ctrl-block + .ctrl-block {
  margin-top: 1rem;
  padding-top: 0.9rem;
  border-top: 1px solid var(--line);
}

.ctrl-block h3 {
  margin: 0 0 0.35rem;
  font-size: 0.95rem;
}

.help {
  margin: 0 0 0.65rem;
  font-size: 0.8rem;
  line-height: 1.4;
}

.help.nested {
  margin: -0.15rem 0 0.55rem 1.55rem;
}

fieldset {
  border: 1px solid var(--line);
  border-radius: 0.55rem;
  margin: 0 0 0.55rem;
  padding: 0.45rem 0.55rem 0.6rem;
}

legend {
  padding: 0 0.25rem;
  font-size: 0.82rem;
  font-weight: 600;
}

.contrast-slide {
  display: flex;
  align-items: center;
  gap: 0.4rem;
  margin: 0.35rem 0 0.2rem;
  font-size: 0.8rem;
}

.contrast-slide input[type="range"] {
  flex: 1;
  min-width: 0;
}

.clip-readout {
  min-width: 2.4rem;
  text-align: right;
  color: var(--ink);
}

.muted { color: var(--muted); }

.row, .check {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  margin: 0.28rem 0;
  font-size: 0.86rem;
}

.row span {
  min-width: 4.2rem;
  color: var(--muted);
}

.row input[type="number"],
.row input[type="range"] {
  flex: 1;
}

input[type="number"],
input[type="range"] {
  width: 100%;
  accent-color: var(--accent);
}

input[type="number"] {
  border: 1px solid var(--line);
  border-radius: 0.4rem;
  padding: 0.28rem 0.4rem;
  background: #fff;
  font-family: var(--mono);
  font-size: 0.82rem;
}

.btn {
  margin-top: 0.25rem;
  border: 1px solid var(--line);
  background: #fff;
  color: var(--ink);
  border-radius: 0.45rem;
  padding: 0.35rem 0.55rem;
  font: inherit;
  font-size: 0.82rem;
  cursor: pointer;
}

.btn:hover { border-color: var(--accent); color: var(--accent); }

.readout {
  margin-top: 0.25rem;
  padding: 0.35rem 0.45rem;
  border-radius: 0.4rem;
  background: #eef4f6;
  font-size: 0.86rem;
}

.mono { font-family: var(--mono); }

.status {
  margin: 0.4rem 0 0;
  font-size: 0.8rem;
}

@media (max-width: 1100px) {
  .workspace { grid-template-columns: 1fr; }
  .controls { position: static; max-height: none; }
}

@media (max-width: 720px) {
  .panels { grid-template-columns: 1fr; }
  .panel-wide { grid-column: auto; }
}