body {
  margin: 0;
  padding: 0;
  display: flex;
  justify-content: center;
  align-items: center;
  height: 100vh;
  background-color: #f0f0f0; /* رنگ پس‌زمینه دلخواه */
}

.loader {
  width: 100%;
  max-width: 400px; /* حداکثر عرض دلخواه */
  height: 4.8px;
  display: inline-block;
  position: relative;
  background: rgba(103, 114, 129, 0.553);
  overflow: hidden;
}

.loader::after {
  content: '';
  width: 192px;
  height: 4.8px;
  background: #38334e;
  position: absolute;
  top: 0;
  left: 0;
  box-sizing: border-box;
  animation: animloader 2s linear infinite;
}

@keyframes animloader {
  0% {
    left: 0;
    transform: translateX(-100%);
  }
  100% {
    left: 100%;
    transform: translateX(0%);
  }
}