body {
  font-family: Arial, sans-serif;
  text-align: center;
  background-color: #1b1b1b;
  margin: 0;
  padding: 0;
}

#otp-container, #invalid, #copied {
  display: none;
}

#invalid, #copied {
  color: #FFF;
  font-size: .8rem;
}

#otp {
  cursor: pointer;
}

.container {
  background: #1b1b1b;
  width: 300px;
  margin: 50px auto;
  border-radius: 10px;
  color: #FFF;
  display: flex;
  flex-direction: column;
  justify-content: center;
}

.container h2 {
  padding: .5rem 0;
  border-bottom: 3px solid #313131;
}

input {
  width: 100%;
  padding: 10px;
  margin: 10px 0;
  border-radius: 5px;
  border: none;
  background-color: #1b1b1b;
  color: #FFF;
  font-size: 1.2rem;
}

input:focus {
  outline: none;
}

input[type="submit"] {
  background-color: #007bff;
  color: #FFF;
  cursor: pointer;
}

.otp-display {
  font-size: 24px;
  font-weight: bold;
  margin: 20px 0;
}

.progress-container {
  position: relative;
  width: 100px;
  height: 100px;
  margin: 20px auto;
}

svg {
  transform: rotate(-90deg);
}

.progress-background {
  fill: none;
  stroke: #1b1b1b;
  stroke-width: 20;
}

.progress-circle {
  fill: none;
  stroke: #007bff;
  stroke-width: 20;
  stroke-dasharray: 251.2;
  stroke-dashoffset: 0;
  transition: stroke-dashoffset 1s linear;
}

#timer {
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  font-size: 18px;
  font-weight: bold;
}

span.footer {
  font-size: .5rem;
  color: #727272;
  position: absolute;
  bottom: 0px;
  left: 50%;
  transform: translateX(-50%);
}

.hint {
  font-size: .8rem;
  color: #727272;
  margin-top: 10px;
  text-align: justify;
}