html {width: 100%;}
body {
  width: 100%;
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: center;
  flex-flow: column;
  margin: 0;
  overflow: hidden;
  font-family: "Lato", sans-serif;
  background-color: #4D394B;
}

.sudoku-container {
  border: 4px solid #1f171f;
  margin: 0 auto;
  position: relative;
  padding: 0 2px;
}
.sudoku-container::before, .sudoku-container::after {
  position: absolute;
  border-style: solid;
  pointer-events: none;
  content: "";
}
.sudoku-container::before {
  width: 215px;
  border-width: 0 4px;
  border-color: transparent #1f171f transparent #1f171f;
  top: 4px;
  left: 215px;
  bottom: 4px;
}
.sudoku-container::after {
  height: 208px;
  border-width: 4px 0;
  border-color: #1f171f transparent #1f171f transparent;
  left: 4px;
  top: 208px;
  right: 4px;
}

tr:nth-child(1) td:nth-child(3) input,
tr:nth-child(1) td:nth-child(6) input {
  margin: 0 10px 0 0;
}

tr:nth-child(3) input,
tr:nth-child(6) input {
  margin: 0 0 10px 0;
}

.sudoku-container input {
  width: 60px;
  height: 60px;
  text-align: center;
  font-size: 20px;
  padding: 0;
  border: 3px #2E222D solid;
  background-color: #2E222D;
  color: #eee;
}
.sudoku-container input:focus {
  border-color: #4C9689;
}
.sudoku-container input.disabled {
  cursor: not-allowed;
}

.sudoku-container .invalid {
  border-color: #e74c3c;
}
.sudoku-container .invalid:focus {
  border-color: #e74c3c;
}

.sudoku-container.valid-matrix {
  border-color: #4C9689;
}

#controls {
  margin: 20px 0;
}

.btn.primary {
  background-color: #4C9689;
  box-shadow: inset 0 -3px #3b746a;
}


.btn, .bttn {
  border: none;
  font-family: "Lato", sans-serif;
  font-size: 14px;
  color: inherit;
  background: none;
  cursor: pointer;
  padding: 8px 12px;
  display: inline-block;
  text-transform: uppercase;
  letter-spacing: 1px;
  font-weight: 700;
  outline: none;
  position: relative;
  background: #95a5a6;
  color: #fff;
  box-shadow: inset 0 -3px #798d8f;
  border-radius: 3px;
}
.btn.icon, .bttn.icon {
  padding-left: 35px;
}
.btn .mdi, .bttn .mdi {
  font-size: 21px;
  font-size: 21px;
  display: inline-block;
  position: relative;
}
.btn .mdi:before, .bttn .mdi:before {
  position: absolute;
  left: -25px;
  top: -17px;
}

.btn.primary, .bttn.primary {
  background-color: #3498db;
  box-shadow: inset 0 -3px #217dbb;
}

.btn.danger, .bttn.danger {
  background-color: #c0392b;
  box-shadow: inset 0 -3px #962d22;
}

.btn.success, .bttn.success {
  background-color: #27ae60;
  box-shadow: inset 0 -3px #1e8449;
}

.btn.orange, .bttn.orange {
  background-color: #e67e22;
  box-shadow: inset 0 -3px #bf6516;
}

.btn.dark, .bttn.dark {
  background-color: #34495e;
  box-shadow: inset 0 -3px #22303d;
}

textarea, select, input[type="text"] {
  font-family: "Lato", sans-serif;
  border: 2px solid #95a5a6;
  border-radius: 3px;
  padding: 6px 12px;
  line-height: 18px;
}
textarea::-webkit-input-placeholder, select::-webkit-input-placeholder, input[type="text"]::-webkit-input-placeholder {
  color: #95a5a6;
  font-family: "Lato", sans-serif;
  font-size: 14px;
  background: none;
  cursor: pointer;
  text-transform: uppercase;
  letter-spacing: 1px;
  font-weight: 700;
  opacity: 0.8;
}
textarea::-moz-placeholder, select::-moz-placeholder, input[type="text"]::-moz-placeholder {
  color: #95a5a6;
  font-family: "Lato", sans-serif;
  font-size: 14px;
  background: none;
  cursor: pointer;
  text-transform: uppercase;
  letter-spacing: 1px;
  font-weight: 700;
  opacity: 0.8;
}
textarea:-ms-input-placeholder, select:-ms-input-placeholder, input[type="text"]:-ms-input-placeholder {
  color: #95a5a6;
  font-family: "Lato", sans-serif;
  font-size: 14px;
  background: none;
  cursor: pointer;
  text-transform: uppercase;
  letter-spacing: 1px;
  font-weight: 700;
  opacity: 0.8;
}
textarea::-ms-input-placeholder, select::-ms-input-placeholder, input[type="text"]::-ms-input-placeholder {
  color: #95a5a6;
  font-family: "Lato", sans-serif;
  font-size: 14px;
  background: none;
  cursor: pointer;
  text-transform: uppercase;
  letter-spacing: 1px;
  font-weight: 700;
  opacity: 0.8;
}
textarea::placeholder, select::placeholder, input[type="text"]::placeholder {
  color: #95a5a6;
  font-family: "Lato", sans-serif;
  font-size: 14px;
  background: none;
  cursor: pointer;
  text-transform: uppercase;
  letter-spacing: 1px;
  font-weight: 700;
  opacity: 0.8;
}

.success textarea, .success select, .success input[type="text"] {
  border-color: #27ae60;
}

.error textarea, .error select, .error input[type="text"] {
  border-color: #c0392b;
}

@media (max-width:799px) {
  body{height: 800px; overflow: visible; justify-content: start;}
  .sudoku-container input{width: 100%; height: 100%; border: 3px #4E222D}
  .sudoku-container::after,
  .sudoku-container::before{display: none;}

  .sudoku-container tr td:nth-child(6),
  .sudoku-container tr td:nth-child(3){
    padding-right: 7px;
  }
  .sudoku-container tr:nth-child(3) input, .sudoku-container tr:nth-child(6) input {
    margin: 0 0 7px 0;
}