@import url('https://fonts.googleapis.com/css2?family=Nunito&display=swap');
* {
  margin: 0;
  padding: 0;
  box-sizing: inherit;
}
.modalH1 {
  font-size: 2.5rem;
  margin-bottom: 2rem;
  color: #333;
}
html {
  font-size: 62.5%;
  box-sizing: border-box;
}
body {
  background-image: url('bg.jpg');
  font-family: 'Nunito', sans-serif;
  font-weight: 400;
  height: 100vh;
  color: #eee;
  /* background-image: linear-gradient(to top left #753682 0%#bf2e34 100%); */
  background-color: rgb(39, 39, 39);
  display: flex;
  align-items: center;
  justify-content: center;
}
header {
  position: absolute;
  height: 96vh;
}
.headerH1 {
  color: aliceblue;
  font-size: 4rem;
  text-align: center;
  position: relative;
}
p {
  font-size: 1.8rem;
  color: #333;
}
main {
  position: relative;
  width: 85rem;
  height: 65rem;
  background-color: rgba(27, 27, 27, 0.35);
  backdrop-filter: blur(200px);
  filter: blur();
  box-shadow: 0 3rem 5rem rgba(255, 0, 0, 0.25);
  border-radius: 9px;
  overflow: hidden;
  display: flex;
}
.sudoku {
  flex: 50%;
  padding: 3rem;
  position: relative;
  display: flex;
  flex-direction: column;
  align-items: center;
}
input {
  width: 60px;
  height: 60px;
  background: none;
  border: 4px solid #eee;
  font-family: inherit;
  color: inherit;
  font-size: 3rem;
  text-align: center;
}

/* buttons */
.btn--solve {
  right: 15%;
  top: 2.5%;
}
.btn--reset {
  left: 15%;
  bottom: 4.2%;
}
button span {
  cursor: pointer;
  display: inline-block;
  position: relative;
  transition: 0.5s;
}
.btn--solve span:after {
  content: '💡';
  position: absolute;
  opacity: 0;
  top: 0;
  right: -20px;
  transition: 0.5s;
}
.btn--reset span:after {
  content: '🔄';
  position: absolute;
  opacity: 0;
  top: 0;
  right: -20px;
  transition: 0.5s;
}
.btn--solve:hover span {
  padding-right: 25px;
}
.btn--reset:hover span {
  padding-right: 25px;
}
.btn--solve:hover span:after {
  opacity: 1;
  right: 0;
}
.btn--reset:hover span:after {
  opacity: 1;
  right: 0;
}
.btn {
  position: relative;
  color: #444;
  background: none;
  font-family: inherit;
  border: none;
  font-size: 1.8rem;
  text-transform: uppercase;
  cursor: pointer;
  font-weight: 400;
  background-color: white;
  /* background-color: rgba(255, 255, 255, 0.6)*/
  backdrop-filter: blur(10px);
  padding: 0.7rem 2.5rem;
  border-radius: 50rem;
  box-shadow: 0 1.75rem 3.5rem rgb(0 0 0 / 10%);
  transition: all 0.5s;
}
.btn:active {
  transform: translate(0%, 2px);
  box-shadow: 0 1rem 2rem rgba(0, 0, 0, 0.15);
}

.btn:focus {
  outline: none;
}

.btn--close {
  position: absolute;
  top: 10%;
  right: 5%;
  font-size: 3rem;
  color: #333;
  cursor: pointer;
  border: none;
  background: none;
  font-family: inherit;
  font-weight: 400;
}
.btn--theme00,
.btn--theme01,
.btn--theme02 {
  display: block;
  bottom: 41rem;
  left: 34.9rem;
  border: 2px solid #333;
}

/* modal and overylay hidden */
.hidden {
  display: none;
}

/* row margins and column margins for proper sudoku format style */
.rbold {
  margin-bottom: 2px;
  /* border-bottom: 4px solid #eee; */
}
.bold {
  margin-right: -3px;
}

.modal {
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  width: 70%;
  background-color: white;
  padding: 6rem;
  border-radius: 5px;
  box-shadow: 0 3rem 5rem rgb(0 0 0 / 30%);
  z-index: 10;
}

.overlay {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background-color: rgba(0, 0, 0, 0.6);
  backdrop-filter: blur(3px);
  z-index: 5;
}