:root {
  --paper: #ffffff;
  --paper-grid: #e2e8f0;
  --ink: #222f55;
  --muted: #64748b;
  --line: #d8e1ee;
  --tool: #ffffff;
  --accent: #0571d3;
  --accent-soft: #e9f4ff;
  --accent-ink: #ffffff;
  --danger: #b42318;
  --shadow: 0 16px 34px rgba(34, 47, 85, 0.14);
  font-family: Arial, Helvetica, sans-serif;
}

* {
  box-sizing: border-box;
}

[hidden] {
  display: none !important;
}

html,
body {
  width: 100%;
  height: 100%;
}

body {
  margin: 0;
  overflow: hidden;
  background: #f8fafc;
  color: var(--ink);
}

button,
input {
  font: inherit;
}

.whiteboard-app {
  display: grid;
  grid-template-rows: auto 1fr;
  width: 100%;
  height: 100%;
}

.topbar {
  position: relative;
  z-index: 20;
  display: grid;
  grid-template-columns: auto 1fr auto;
  align-items: center;
  gap: 10px;
  min-height: 48px;
  padding: 6px 8px;
  border-bottom: 1px solid var(--line);
  background: rgba(255, 255, 255, 0.96);
  backdrop-filter: blur(12px);
}

.brand,
.tool-group {
  display: flex;
  align-items: center;
  gap: 6px;
}

.brand {
  color: #222f55;
  font-size: 0.92rem;
  font-weight: 700;
}

.brand-mark {
  display: grid;
  place-items: center;
  width: 34px;
  height: 34px;
  border-radius: 8px;
  background: var(--accent);
  color: var(--accent-ink);
  font-size: 1rem;
  font-weight: 800;
}

.tool-button,
.recognition-panel button {
  min-height: 34px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--tool);
  color: #334155;
  cursor: pointer;
}

.tool-button {
  padding: 0 10px;
  font-size: 0.9rem;
  font-weight: 700;
}

.icon-button {
  width: 36px;
  padding: 0;
  font-size: 1.1rem;
}

.tool-button.is-active {
  border-color: var(--accent);
  background: var(--accent);
  color: var(--accent-ink);
}

.tool-button:hover,
.recognition-panel button:hover {
  border-color: var(--accent);
  color: var(--accent);
}

.tool-button.is-active:hover,
#plot-recognized:hover,
#save-training-sample:hover,
.floating-save-training:hover {
  color: var(--accent-ink);
}

.tool-button.danger {
  color: var(--danger);
}

.status {
  min-width: 0;
  overflow: hidden;
  color: var(--muted);
  font-size: 0.86rem;
  text-align: right;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.status.is-error {
  color: var(--danger);
}

.board {
  position: relative;
  min-width: 0;
  min-height: 0;
  overflow: hidden;
  background:
    linear-gradient(var(--paper-grid) 1px, transparent 1px),
    linear-gradient(90deg, var(--paper-grid) 1px, transparent 1px),
    var(--paper);
  background-size: 30px 30px;
  touch-action: none;
}

#ink-canvas {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  cursor: crosshair;
  touch-action: none;
}

.selection-box {
  position: absolute;
  z-index: 8;
  border: 2px solid var(--accent);
  background: rgba(23, 111, 104, 0.08);
  pointer-events: none;
}

.plots-layer {
  position: absolute;
  inset: 0;
  pointer-events: none;
}

.plot-card {
  position: absolute;
  z-index: 10;
  width: min(520px, calc(100vw - 32px));
  min-height: 370px;
  overflow: hidden;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--tool);
  box-shadow: var(--shadow);
  pointer-events: auto;
}

.plot-card header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 10px;
  min-height: 40px;
  padding: 0 10px;
  border-bottom: 1px solid var(--line);
  background: #f8fafc;
  cursor: grab;
}

.plot-card h2 {
  margin: 0;
  overflow: hidden;
  font-size: 0.92rem;
  font-weight: 500;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.plot-card button {
  min-height: 30px;
  border: 0;
  background: transparent;
  color: var(--danger);
  cursor: pointer;
}

.plot-host {
  display: block;
  width: 100%;
  height: 330px;
  cursor: grab;
  touch-action: none;
}

.plot-host:active {
  cursor: grabbing;
}

.result-card {
  position: absolute;
  z-index: 20;
  width: min(390px, calc(100vw - 32px));
  overflow: hidden;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: rgba(255, 255, 255, 0.99);
  box-shadow: var(--shadow);
  pointer-events: auto;
}

.result-card header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 10px;
  padding: 10px 12px;
  border-bottom: 1px solid var(--line);
  background: #f8fafc;
  cursor: grab;
}

.result-card h2 {
  margin: 0;
  font-size: 0.96rem;
  font-weight: 650;
}

.result-card button {
  min-height: 30px;
  border: 0;
  background: transparent;
  color: var(--danger);
  cursor: pointer;
}

.result-body {
  display: grid;
  gap: 6px;
  padding: 12px;
  font-family: "Cascadia Code", "SFMono-Regular", Consolas, monospace;
  font-size: 0.95rem;
}

.result-body p {
  margin: 0;
}

.recognition-panel {
  position: absolute;
  z-index: 30;
  left: 50%;
  bottom: 10px;
  display: grid;
  grid-template-columns: auto minmax(180px, 420px) auto auto;
  align-items: center;
  gap: 8px;
  width: min(700px, calc(100% - 20px));
  padding: 8px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: rgba(255, 255, 255, 0.96);
  box-shadow: var(--shadow);
  transform: translateX(-50%);
}

.trainer-panel {
  position: absolute;
  z-index: 60;
  left: 10px;
  top: 10px;
  display: flex;
  align-items: center;
  gap: 10px;
  max-width: calc(100% - 36px);
  padding: 8px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: rgba(255, 255, 255, 0.96);
  box-shadow: var(--shadow);
  pointer-events: auto;
}

.trainer-panel div {
  display: grid;
  gap: 2px;
  min-width: 170px;
}

.trainer-panel span {
  color: var(--muted);
  font-size: 0.82rem;
}

.trainer-panel strong {
  font-family: "Cascadia Code", "SFMono-Regular", Consolas, monospace;
  font-size: 1.12rem;
  font-weight: 600;
}

.trainer-panel button {
  position: relative;
  z-index: 61;
  min-height: 38px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--tool);
  color: var(--ink);
  cursor: pointer;
  white-space: nowrap;
}

#save-training-sample {
  border-color: var(--accent);
  background: var(--accent);
  color: var(--accent-ink);
}

.trainer-write-zone {
  position: absolute;
  z-index: 6;
  left: 50%;
  top: 50%;
  width: min(760px, calc(100% - 80px));
  height: min(230px, calc(100% - 180px));
  min-height: 160px;
  border: 2px dashed var(--accent);
  border-radius: 8px;
  background: rgba(23, 111, 104, 0.045);
  color: var(--accent);
  pointer-events: none;
  transform: translate(-50%, -50%);
}

.trainer-write-zone span {
  position: absolute;
  left: 12px;
  top: 10px;
  padding: 2px 6px;
  background: var(--paper);
  font-size: 0.84rem;
}

.floating-save-training {
  position: absolute;
  z-index: 62;
  left: 50%;
  bottom: 24px;
  min-width: min(360px, calc(100% - 40px));
  min-height: 52px;
  border: 1px solid var(--accent);
  border-radius: 8px;
  background: var(--accent);
  color: var(--accent-ink);
  box-shadow: var(--shadow);
  cursor: pointer;
  font-size: 1rem;
  font-weight: 600;
  pointer-events: auto;
  transform: translateX(-50%);
}

.recognition-panel span {
  color: var(--muted);
  font-size: 0.88rem;
}

.recognition-panel input {
  min-width: 0;
  min-height: 38px;
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 0 10px;
  font-family: "Cascadia Code", "SFMono-Regular", Consolas, monospace;
}

.recognition-panel button {
  padding: 0 12px;
}

#plot-recognized {
  border-color: var(--accent);
  background: var(--accent);
  color: var(--accent-ink);
}

@media (max-width: 760px) {
  .topbar {
    grid-template-columns: 1fr;
    gap: 8px;
  }

  .tool-group {
    flex-wrap: wrap;
  }

  .status {
    text-align: left;
    white-space: normal;
  }

  .recognition-panel {
    grid-template-columns: 1fr auto;
  }

  .trainer-panel {
    align-items: stretch;
    flex-direction: column;
  }

  .recognition-panel span {
    display: none;
  }

  .recognition-panel input {
    grid-column: 1 / -1;
  }
}