body {
  margin: 0;
  display: flex;
  justify-content: center;
  height: 100vh;
  align-items: center;
  background-color: white;
}

.container {
  text-align: center;
}

.progress-container {
  width: 700px; /* increased width */
  display: flex;
  position: relative;
  justify-content: space-between;
}

.progress-bar-back {
  position: absolute;
  height: 8px; /* thicker progress line */
  width: 100%;
  background-color: lightgray;
  border: none;
  z-index: -1;
  margin: 0;
  top: 50%;
  transform: translateY(-50%);
}

.progress-bar-front {
  position: absolute;
  height: 8px; /* thicker front progress */
  width: 0%;
  background-color: green;
  border: none;
  z-index: -1;
  margin: 0;
  top: 50%;
  transform: translateY(-50%);
  transition: 0.4s linear width;
}

.step {
  width: 60px;       /* bigger circle */
  height: 60px;      /* bigger circle */
  background-color: white;
  border-radius: 50%;
  display: flex;
  justify-content: center;
  align-items: center;
  border: 6px solid lightgray; /* thicker border */
  color: lightgray;
  font-size: 24px;   /* icon size inside circle */
  position: relative;
}

.step.checked {
  color: green;
  border-color: green;
  transition: all 0.4s linear;
  transition-delay: 0.3s;
}

.step.checked small {
  position: absolute;
  bottom: -25px;      /* distance from circle */
  font-family: cursive;
  font-size: 16px;    /* larger text */
}

.btn {
  background-color: slateblue;
  border: none;
  color: white;
  padding: 14px 28px;   /* bigger buttons */
  margin: 100px 15px 0; /* increased spacing */
  border-radius: 6px;
  cursor: pointer;
  box-shadow: 0 6px 12px rgba(0, 0, 0, 0.3);
  font-size: 18px;      /* bigger text */
}

.btn:hover {
  opacity: 0.9;
}

.btn:active {
  transform: scale(0.97);
}

.btn:disabled {
  background-color: lightgray;
}

@media (max-width: 768px) {
  .progress-container {
    width: 90vw;
  }

  .step {
    width: 50px;
    height: 50px;
    font-size: 20px;
    border-width: 5px;
  }

  .step.checked small {
    font-size: 14px;
    bottom: -20px;
  }

  .btn {
    padding: 12px 20px;
    font-size: 16px;
    margin: 70px 10px 0;
  }
}