:root {
  --bg: #14161b;
  --panel: #1d2027;
  --panel-2: #252932;
  --border: #343a46;
  --text: #d7dce5;
  --text-dim: #8b93a1;
  --accent: #ff6a00;
  --accent-2: #00c2ff;
  --danger: #e5484d;
}

* { box-sizing: border-box; }

html, body {
  margin: 0;
  height: 100%;
  background: var(--bg);
  color: var(--text);
  font: 14px/1.4 "Segoe UI", system-ui, sans-serif;
  overflow: hidden;
}

.hidden { display: none !important; }

/* ---------- toolbar ---------- */
#toolbar {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 6px 10px;
  background: var(--panel);
  border-bottom: 1px solid var(--border);
  height: 46px;
  overflow-x: auto;
  scrollbar-width: thin;
}

#app-title {
  font-weight: 600;
  color: var(--accent);
  margin-right: 8px;
  white-space: nowrap;
}

#track-name {
  width: 200px;
  min-width: 110px;
  flex-shrink: 1;
  background: var(--panel-2);
  border: 1px solid var(--border);
  color: var(--text);
  border-radius: 5px;
  padding: 5px 8px;
}

.toolbar-sep {
  width: 1px;
  height: 24px;
  background: var(--border);
  margin: 0 4px;
}

.toolbar-spacer { flex: 1; }

#measure-total {
  color: var(--accent-2);
  font-variant-numeric: tabular-nums;
  min-width: 90px;
}

#snap-label {
  display: flex;
  align-items: center;
  gap: 4px;
  color: var(--text-dim);
  user-select: none;
}

button {
  background: var(--panel-2);
  border: 1px solid var(--border);
  color: var(--text);
  border-radius: 5px;
  padding: 5px 10px;
  cursor: pointer;
  white-space: nowrap;
}
button:hover { background: #2e3440; }
button.primary { background: var(--accent); border-color: var(--accent); color: #fff; }
button.primary:hover { filter: brightness(1.1); }
button.danger { color: var(--danger); border-color: var(--danger); }
button.danger:hover { background: rgba(229, 72, 77, 0.15); }
button.toggle.active { background: var(--accent-2); border-color: var(--accent-2); color: #06232e; }

/* ---------- layout ---------- */
#main {
  display: flex;
  height: calc(100% - 46px);
}

#sidebar {
  width: 240px;
  min-width: 240px;
  background: var(--panel);
  border-right: 1px solid var(--border);
  padding: 10px;
  display: flex;
  flex-direction: column;
  gap: 12px;
  overflow-y: auto;
}

#sidebar h2 {
  font-size: 12px;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--text-dim);
  margin: 0 0 6px;
}

#viewport {
  position: relative;
  flex: 1;
  min-width: 0;
}

#canvas3d {
  width: 100%;
  height: 100%;
  display: block;
}

#status-bar {
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  padding: 4px 10px;
  background: rgba(20, 22, 27, 0.75);
  color: var(--text-dim);
  font-size: 12px;
  pointer-events: none;
}

/* ---------- palette ---------- */
#palette {
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.palette-item {
  display: flex;
  align-items: center;
  gap: 10px;
  background: var(--panel-2);
  border: 1px solid var(--border);
  border-radius: 6px;
  padding: 6px 8px;
  cursor: pointer;
  user-select: none;
}
.palette-item:hover { border-color: var(--text-dim); }
.palette-item.active { border-color: var(--accent); background: rgba(255, 106, 0, 0.1); }
.palette-item canvas { flex: none; }
.palette-item .palette-name { font-size: 13px; }

/* ---------- properties ---------- */
/* Floating gate properties panel over the right side of the viewport. */
#props {
  position: absolute;
  top: 12px;
  right: 12px;
  width: 232px;
  max-height: calc(100% - 50px);
  overflow-y: auto;
  background: rgba(29, 32, 39, 0.92);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 12px;
  box-shadow: 0 6px 24px rgba(0, 0, 0, 0.45);
  z-index: 10;
}

#props h2 {
  font-size: 12px;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--text-dim);
  margin: 0 0 8px;
}

.prop-grid {
  display: grid;
  grid-template-columns: auto 1fr;
  gap: 6px 10px;
  align-items: center;
}
.prop-grid label { color: var(--text-dim); font-size: 12px; }
.prop-grid input,
.prop-grid select {
  width: 100%;
  background: var(--bg);
  border: 1px solid var(--border);
  color: var(--text);
  border-radius: 4px;
  padding: 4px 6px;
  font-variant-numeric: tabular-nums;
}

.prop-actions {
  display: flex;
  gap: 6px;
  margin-top: 10px;
}
.prop-actions button { flex: 1; }

.hint { color: var(--text-dim); font-size: 12px; margin: 8px 0 0; }
.hint.error { color: var(--danger); }
.hint.error:empty { display: none; }

.prop-grid input[type="color"] {
  padding: 2px;
  height: 28px;
  cursor: pointer;
}

#gate-preview {
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: 4px;
  padding: 6px;
  display: flex;
  justify-content: center;
}

#btn-new-gate { width: 100%; }

#sidebar-footer { margin-top: auto; }

/* ---------- dialogs ---------- */
#modal-overlay {
  position: fixed;
  inset: 0;
  background: rgba(0, 0, 0, 0.55);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 100;
}

.dialog {
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 16px;
  min-width: 320px;
  max-width: 460px;
  max-height: 80vh;
  overflow-y: auto;
}
.dialog h2 { margin: 0 0 12px; font-size: 16px; }

.dialog-actions {
  display: flex;
  justify-content: flex-end;
  gap: 8px;
  margin-top: 14px;
}

#track-list { display: flex; flex-direction: column; gap: 6px; min-width: 360px; }
.track-row {
  display: flex;
  align-items: center;
  gap: 8px;
  background: var(--panel-2);
  border: 1px solid var(--border);
  border-radius: 6px;
  padding: 8px 10px;
}
.track-row .track-title { flex: 1; cursor: pointer; }
.track-row .track-title:hover { color: var(--accent-2); }
.track-row .track-date { color: var(--text-dim); font-size: 12px; }
.track-row button { padding: 2px 8px; }
#track-list .empty { color: var(--text-dim); padding: 12px; text-align: center; }

#help-table { border-collapse: collapse; }
#help-table td { padding: 3px 12px 3px 0; }
#help-table td:first-child { color: var(--text-dim); }
kbd {
  background: var(--panel-2);
  border: 1px solid var(--border);
  border-radius: 3px;
  padding: 1px 5px;
  font-size: 12px;
}