body {
  margin: 0;
  height: 100vh;
  overflow: hidden;
  font-family: "Segoe UI", Tahoma, sans-serif;
}

.split {
  display: flex;
  height: 100vh;
  width: 100vw;
}

.gutter {
  background-color: #ffffff;
  /* background-repeat: no-repeat;
  background-position: 50%; */
  cursor: col-resize;
  /* transition: background 0.3s ease, transform 0.2s ease; */
}

.gutter:hover {
   background-color: #84a9ee;
}

.gutter.gutter-horizontal {
  background-image: url("data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAUAAAAeCAYAAADkftS9AAAAIklEQVQoU2M4c+bMfxAGAgYYmwGrIIiDjrELjpo5aiZeMwF+yNnOs5KSvgAAAABJRU5ErkJggg==");
  cursor: col-resize;
  background-repeat: no-repeat;
  background-position: center center;
  background-size: auto;
}

.panel {
  position: relative;
  overflow: hidden;
}

iframe {
  width: 100%;
  height: 100%;
  border: none;
}

/* 🔹 Toolbar / título vertical */
.vertical-title {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  display: none;
  align-items: center;
  justify-content: center;
  color: #fff;
  font-weight: bold;
  font-size: 18px;
  writing-mode: vertical-rl;
  text-orientation: mixed;
  background: linear-gradient(135deg, #4a90e2, #357ae8);
  text-shadow: 1px 1px 3px rgba(0, 0, 0, 0.3);
  cursor: pointer;
}

.vertical-title.visible {
  display: flex;
  animation: fadeIn 0.4s;
}

@keyframes fadeIn {
  from {
    opacity: 0;
  }
  to {
    opacity: 1;
  }
}