* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}
body {
  font-family: "Arial", sans-serif;
  background: #000000;
  color: #ffffff;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  height: 100vh;
  overflow: hidden;
}
h1 {
  font-size: 3rem;
  margin-bottom: 20px;
}
.container {
  display: flex;
  flex-wrap: wrap;
  gap: 20px;
  justify-content: center;
  align-items: center;
  width: 100%;
}
.card {
  background: #121212;
  border-radius: 10px;
  width: 180px;
  padding: 15px;
}
.card h2 {
  font-size: 1rem;
  margin-bottom: 10px;
  text-align: center;
}
.timer {
  display: flex;
  justify-content: space-around;
  font-size: 1rem;
}
.unit {
  display: flex;
  flex-direction: column;
  align-items: center;
}
.unit span {
  font-size: 2rem;
  font-weight: bold;
  opacity: 1;
  transition: opacity 0.3s ease-in-out;
}
.unit span.fade-out {
  opacity: 0;
}