html, body {
  height: 100%;
  margin: 0;
  overflow: hidden;
}

/* #main-canvas-container {
  width: 100%;
  min-height: 30em;
  margin-top: 0.5em;
  margin-bottom: 0.5em;
} */

/* =====  Container switches between vertical & horizontal  ===== */
#flex-container {
  display: flex;
  height: 100%;
  width: 100%;
}

/* default: two columns */
#flex-container.split-vertical {
  flex-direction: row;
}
/* alternative: two rows */
#flex-container.split-horizontal {
  flex-direction: column;
}

/* =====  Panels  ===== */
.panel {
  display: flex;
  overflow: hidden; /* clip overflowing child content */
  flex: 1 1 50%;     /* start 50 % / 50 % */
  min-width: 0;      /* allow flexbox to shrink below content width */
  min-height: 0;
}

/* Left‑column specific structure */
.panel-left {
  flex-direction: column;
}
.left-head {
  padding: 1em;
  background: #f0f0f0;
  border-bottom: 1px solid #ccc;
  flex: 0 0 auto; /* height is content‑driven */
}
.left-body {
  flex: 1 1 auto;  /* fill remaining height */
  background: #fafafa;
  display: flex;
  align-items: center;
  justify-content: center;
}

/* Right‑column – three equal vertical sections */
.panel-right {
  flex-direction: column;
}
.section {
  flex: 1 1 auto;
  border-top: 1px solid #e0e0e0;
  display: flex;
  align-items: center;
  justify-content: center;
}
.section:first-child {
  flex: 0 0 auto;
  border-top: none;
  padding: 0.5em;
}

/* =====  Resizer bar  ===== */
.resizer {
  background: #d0d0d0;
  flex: 0 0 0.3em;          /* thickness */
  user-select: none;
  touch-action: none;
}
.split-vertical .resizer {
  width: 0.3em;
  height: 100%;
  cursor: col-resize;
}
/* When layout becomes horizontal the bar turns horizontal */
.split-horizontal .resizer {
  width: 100%;
  height: 0.3em;
  cursor: row-resize;
}

.material-symbols-outlined {
  font-variation-settings: "FILL" 1;
  font-size: 1.6em;
  line-height: 1;
}

input[type=button]:not(.icon-button), button:not(.icon-button) {
  font-family: inherit;
  font-size: 1em;
  padding-left: 0.5em;
  padding-right: 0.5em;
  padding-top: 0.2em;
  padding-bottom: 0.2em;
}

input[type=button].icon-button, button.icon-button {
  padding: 0.1em;
}