body {
  margin: 0;
  min-height: 100vh;
  font-family: Arial, sans-serif;
  background: #eef2f7;
}

.app-shell {
  display: grid;
  grid-template-columns: 320px minmax(0, 1fr);
  min-height: 100vh;
}

.sidebar {
  display: flex;
  flex-direction: column;
  gap: 18px;
  padding: 20px;
  background: rgba(255, 255, 255, 0.92);
  box-shadow: 0 0 40px rgba(34, 48, 71, 0.08);
  z-index: 1;
}

h1 {
  margin: 0;
  font-size: 24px;
  color: #223047;
}

h1 span {
  display: block;
  margin-top: 4px;
  font-size: 14px;
  color: #5b677a;
  font-weight: 400;
}

.panel {
  padding: 16px;
  border-radius: 14px;
  background: #f7f9fc;
  box-shadow: inset 0 0 0 1px rgba(34, 48, 71, 0.08);
}

.panel h2 {
  margin: 0 0 12px;
  font-size: 14px;
  text-transform: uppercase;
  letter-spacing: 0.04em;
  color: #66758a;
}

svg {
  width: 100%;
  height: 100%;
  display: block;
  margin: 0 auto;
  background: radial-gradient(circle at top left, #ffffff 0%, #eef2f7 45%, #dde5f1 100%);
}

.legend {
  font-size: 12px;
  fill: #223047;
  pointer-events: none;
}

#strengthForce {
  width: 100%;
  box-sizing: border-box;
  margin-top: 8px;
  padding: 10px 12px;
  border: 1px solid #ccd5e3;
  border-radius: 10px;
  font-size: 16px;
}

.input-drag-container {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

#drop-area {
  min-height: 96px;
  border: 2px dashed #ccc;
  display: flex;
  justify-content: center;
  align-items: center;
  text-align: center;
  color: #666;
  font-size: 16px;
  border-radius: 10px;
  background: rgba(247, 249, 252, 0.92);
  padding: 12px;
  cursor: pointer;
}

#drop-area.hover {
  border-color: #333;
}

#file-list {
  color: #4a5568;
  font-size: 14px;
}

.graph-stage {
  min-width: 0;
  min-height: 100vh;
}

#container {
  width: 100%;
  height: 100vh;
}

#relation-details {
  margin: 0;
  color: #223047;
  font-size: 14px;
  line-height: 1.5;
  white-space: pre-line;
}

.graph-stage text {
  user-select: none;
}

.hint {
  margin: 0;
  color: #66758a;
  font-size: 13px;
  line-height: 1.5;
}

@media (max-width: 960px) {
  .app-shell {
    grid-template-columns: 1fr;
  }

  .graph-stage {
    min-height: 70vh;
  }

  #container {
    height: 70vh;
  }
}