@import url('https://fonts.googleapis.com/css2?family=Poppins:wght@200;300;400;500;600;700&display=swap');
*{
  margin: 0;
  padding: 0;
  box-sizing: border-box;
  font-family: 'Poppins', sans-serif;
} 
nav{
  display: flex;
  height: 80px;
  width: 100%;
  background: #1b1b1b;
  align-items: center;
  justify-content: space-between;
  padding: 0 50px 0 100px;
  flex-wrap: wrap;
  box-shadow: 0 6px 8px 0 rgba(0, 0, 0, 0.32),
  0 6px 16px 0 rgba(0, 0, 0, 0.24),
  0 6px 24px 0 rgba(0, 0, 0, 0.20),
  0 6px 32px 0 rgba(0, 0, 0, 0.14);
}
nav .logo{
  color: #fff;
  font-size: 35px;
  font-weight: 600;
}
nav ul{
  display: flex;
  flex-wrap: wrap;
  list-style: none;
}
nav ul li{
  margin: 0 5px;
}
nav ul li a{
  color: #f2f2f2;
  text-decoration: none;
  font-size: 18px;
  font-weight: 500;
  padding: 8px 15px;
  border-radius: 5px;
  letter-spacing: 1px;
  transition: all 0.3s ease;
}
nav ul li a.active,
nav ul li a:hover{
  color: #111;
  background: #fff;
}
nav .menu-btn i{
  color: #fff;
  font-size: 22px;
  cursor: pointer;
  display: none;
}
sub{
  font-size: 40px;
  color: red;
}
input[type="checkbox"]{
  display: none;
}
@media (max-width: 1000px){
  nav{
    padding: 0 40px 0 50px;
  }
}
@media (max-width: 850px) {
  nav .menu-btn i{
    display: block;
  }
  #click:checked ~ .menu-btn i:before{
    content: "\f00d";
  }
  nav ul{
    position: absolute;
    top: 80px;
    left: -100%;
    background: #111;
    height: 100vh;
    width: 100%;
    text-align: center;
    display: block;
    transition: all 0.3s ease;
    z-index: 2;
  }
  #click:checked ~ ul{
    left: 0;
  }
  nav ul li{
    width: 100%;
    margin: 40px 0;
  }
  nav ul li a{
    width: 100%;
    margin-left: -100%;
    display: block;
    font-size: 20px;
    transition: 0.6s cubic-bezier(0.68, -0.55, 0.265, 1.55);
  }
  #click:checked ~ ul li a{
    margin-left: 0px;
  }
  nav ul li a.active,
  nav ul li a:hover{
    background: none;
    color: cyan;
  }
}

body {
  background-color: #244a43;
}
.container {
  background-color: #387353;
  width: 90%;
  max-width: 31.25em;
  position: absolute;
  transform: translate(-50%, -50%);
  top: 50%;
  left: 50%;
  padding: 5em 3em;
  border-radius: 0.5em;
  box-shadow: -30px 30px 20px rgba(0,0,0,0.3);
}
.container h3 {
  font-size: 1.2em;
  color: #203d5b;
  text-align: center;
  font-weight: 500;
  line-height: 1.8em;
}

.container #submit-btn {
  font-size: 1.2em;
  font-weight: 500;
  display: block;
  margin: 0 auto;
  background-color: #3d6952;
  border-radius: 0.3em;
  border: none;
  outline: none;
  cursor: pointer;
  color: #203d5b;
  padding: 0.6em 2em;
  box-shadow: -20px 20px 12px rgba(0,0,0,0.3);
}
#error-msg {
  text-align: center;
  margin-top: 1em;
  background-color: rgb(205, 141, 152);
  color: #d62f2f;
  padding: 0.2em 0;
}
.container #question {
  background-color: #387353;
  font-size: 2em;
  font-weight: 600;
  color: #203d5b;
  text-align: center;
  display: flex;
  align-items: center;
  justify-content: center;
  margin: 1.4em 0 1em 0;
  padding: 1em 0;
}

.container input {
  font-size: 1em;
  font-weight: 600;
  width: 2.35em;
  color: #203d5b;
  text-align: center;
  padding: 0 0.2em;
  border: none;
  background-color: transparent;
  border-bottom: 0.12em solid #203d5b;
  margin: 0 0.25em;
}
.container input:focus {
  border-color: #f4c531;
  outline: none;
}
/*Hide Number Arrows*/
.container input[type="number"] {
  -moz-appearance: textfield;
}
.container input[type="number"]::-webkit-outer-spin-button,
.container input[type="number"]::-webkit-inner-spin-button {
  -webkit-appearance: none;
  margin: 0;
}
.controls-container {
  position: absolute;
  display: flex;
  align-items: center;
  justify-content: center;
  flex-direction: column;
  background-color: #244a43;
  height: 100%;
  width: 100%;
}

#start-btn {
  font-size: 1.2em;
  font-weight: 500;
  background-color: #387353;
  color: #203d5b;
  border: none;
  outline: none;
  cursor: pointer;
  padding: 0.8em 1.8em;
  border-radius: 0.3em;
  box-shadow: -30px 30px 20px rgba(0,0,0,0.3);
}
#result {
  margin-bottom: 1em;
  font-size: 1.5em;
  color: #203d5b;
}
#result span {
  font-weight: 600;
}

.hide {
  display: none;
}

@media (max-width: 450px){
  .container{
    margin-top: 50px;
  }
}
@media (max-width: 350px){
  .container #question{
    font-size: 22px;
  }
}