* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html {
  background: #2EC4B6;
  font-family: Verdana, Geneva, Tahoma, sans-serif;
}

main {
  width: 100%;
  min-height: 100vh;
  position: relative;
  display: flex;
  align-items: center;
  justify-content: center;
  flex-direction: column;
  padding: 20px 0;
}

main * {
  border-radius: 10px;
}

h1 {
  color: #FFFFFF;
  max-width: 90vw;
  text-align: center;
  font-size: 2rem;
  margin-bottom: 10px;
}

section {
  padding: 20px 5vw;
  margin: 15px 0;
  width: 100%;
  max-width: 450px;
  box-sizing: border-box;
}

#check-section {
  background: #FFFFFF;
}

#check-section p {
  margin-bottom: 25px;
  text-align: center;
}

input {
  border-radius: 0;
  border: none;
  border-bottom: 2px solid #2EC4B6;
  width: 60%;
  font-size: 1.1rem;
  text-align: center;
  padding: 8px 5px;
  margin-bottom: 10px;
}

button {
  background: #CBF3F0;
  padding: 7px 25px;
  margin-left: 10px;
  border: 1px solid #CBF3F0 ;
  font-weight: bold;
  font-size: 1rem;
  cursor: pointer;
  margin-top: 10px;
}

#result {
  margin-top: 20px;
  text-align: center;
  font-size: 1.2rem;
}

#explanation-section {
  background: #FFBF69;
}

/* Responsive styles */
@media (max-width: 600px) {
  h1, section {
    max-width: 98vw;
    width: 98vw;
    padding: 15px 2vw;
  }

  input, button {
    width: 100%;
    margin: 8px 0 0 0;
    font-size: 1rem;
    display: block;
  }

  #check-section p {
    font-size: 1rem;
  }
}