/* 微软 Fluent Design 风格加载页面样式 */
:root {
  --fluent-primary: #0078d4;
  --fluent-background: #f3f2f1;
  --fluent-circle-size: 20px;
  --fluent-circle-spacing: 10px;
}
* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}
html, body {
  height: 100%;
  background: var(--fluent-background);
  display: flex;
  align-items: center;
  justify-content: center;
  overflow: hidden;
}
body {
  font-family: Segoe UI, system-ui, -apple-system, Roboto, "Helvetica Neue", Arial, sans-serif;
}
.fluent-loading-container {
  display: flex;
  align-items: center;
  justify-content: center;
  height: 100%;
  width: 100%;
}
.fluent-spinner {
  display: flex;
  justify-content: space-between;
  width: calc(var(--fluent-circle-size) * 4 + var(--fluent-circle-spacing) * 3);
}
.fluent-circle {
  width: var(--fluent-circle-size);
  height: var(--fluent-circle-size);
  background-color: var(--fluent-primary);
  border-radius: 50%;
  animation: fluent-bounce 1.2s infinite ease-in-out;
}
.fluent-circle:nth-child(1) {
  animation-delay: -0.45s;
}
.fluent-circle:nth-child(2) {
  animation-delay: -0.3s;
}
.fluent-circle:nth-child(3) {
  animation-delay: -0.15s;
}
@keyframes fluent-bounce {
  0%, 80%, 100% {
    transform: scale(0);
  }
  40% {
    transform: scale(1);
  }
}