* {
  box-sizing: border-box;
}
body {
  margin: 0;
  padding: 0;
  background-image: url("../assets/background.svg");
  background-size: cover;
  background-repeat: no-repeat;
  width: 100%;
  height: 100vh;
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
}
.header {
  width: 100%;
  height: 70px;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
}
.title {
  width: 100%;
  margin: 0;
  font-size: clamp(1.5rem, 10vw, 2.5rem);
  color: #ffffff;
  text-align: center;
}
.main {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  /* centrar verticalmente respecto al viewport sin tocar el body */
  min-height: calc(100vh - 140px);
}
.level {
  margin: 1.5rem auto 2rem auto;
  text-align: center;
  color: #ffffff;
  font-size: clamp(1.5rem, 4vw, 2rem);
  font-weight: bold;
}
.board {
  background-color: greenyellow;
  width: clamp(40vh, 90vw, 70vh);
  height: clamp(40vh, 90vw, 70vh);
  border-radius: 50%;
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  align-items: center;  
  overflow: hidden;
  position: relative;
}
.position {
  width: 50%;
  height: 50%;
}
.yellow {
  background-color: yellow;
}
.blue {
  background-color: blue;
}
.red {
  background-color: red;
}
.green {
  background-color: green;
}
.yellow.soft {
  background-color: rgba(236, 236, 45, 0.561);
}
.blue.soft {
  background-color: rgba(69, 69, 236, 0.589);
}
.red.soft {
  background-color: rgba(231, 90, 90, 0.63);
}
.green.soft {
  background-color: rgba(95, 230, 95, 0.637);
}
.btn-start {
  width: clamp(40vh, 80vw, 50vh);
  height: 80px;
  position: absolute;
  top: calc(50% - 40px);
  left: 50%;
  transform: translateX(-50%);
  font-size: clamp(1rem, 4vw, 2rem);
  border-radius: 10px;
  background-color: indigo;
  color: #ffffff;
  border: none;
  cursor: pointer;
  font-weight: bold;
}
.btn-start:hover {
  background-color: rgb(53, 16, 80);
}
.hide {
  display: none;
}
.increase {
  transform: scale(1.05);
}
.footer {
  width: 100%;
  height: 70px;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
}
.btn-about {
  background-color: indigo;
  border: 1px solid indigo;
  box-shadow: #ffffff 0px 0px 5px;
  border-radius: 5px;
  color: #ffffff;
  width: 120px;
  padding: .8rem 2rem;
  margin: 0;
  font-size: 1rem;
  font-weight: bold;
  cursor: pointer;
  outline: none;
}
.btn-about:hover {
  transform: scale(1.05);
}
@media screen and (max-width: 480px) {
  .board {
    width: clamp(35vh, 85vw, 55vh);
    height: clamp(35vh, 85vw, 55vh);
  }
  .btn-start {
    width: clamp(30vh, 75vw, 45vh);
  }
}
@media screen and (max-width: 380px) {
  .board {
    width: clamp(30vh, 80vw, 50vh);
    height: clamp(30vh, 80vw, 50vh);
  }
  .btn-start {
    width: clamp(25vh, 70vw, 40vh);
  }
}
@media screen and (max-width: 330px) {
  .level {
    font-size: clamp(1rem, 3vw, 1.5rem);
  }
  .board {
    width: clamp(25vh, 75vw, 45vh);
    height: clamp(25vh, 75vw, 45vh);
  }
  .btn-start {
    width: clamp(20vh, 65vw, 35vh);
    height: 70px;
    top: calc(50% - 35px);
  }
}