/* 
 * Completely resets form items
 * ----------------------------
 * Super hard reset that removes all borders
 * and radiuses of all form items (including
 * checkboxes and radios)
*/

button {
  border: 0;
  border-radius: 0;
  background-color: transparent;
  font-size: inherit;
  font-family: inherit;
  font-weight: inherit;
  outline: none;
  appearance: none;
  text-align: center;
}

button:hover,
button:active,
button:focus {
  outline: none;
}
 
:root {
  font-family: Helvetica, Arial, sans-serif;
}
 
html {
  font-size: 175%;
  font-weight: 300;
  line-height: 1.3;
}

body {
  background-image: linear-gradient(236deg, #aecbbc, #373b4a);
  height: 100vh;
}
 
.calculator {
  max-width: 550px;
  max-height: auto;
  background-color: #2d2d2d;
  border-radius: 10px;
  margin: 2em auto;
  box-shadow: 0 0 10px 0 rgba(58, 56, 56, 0.5);
  display: grid; 
  grid-template-columns: 1fr; 
  grid-template-rows: 0.2fr 3.6fr;
  gap: 4px; 
  grid-template-areas: 
    "calculator-display"
    "."; 
}

.calculator-display {
  align-self: center; 
  grid-area: calculator-display; 
  height: 100px;
  background-color: #1e1e1e;
  border-radius: 10px 10px 0 0;
  font-size: 3rem;
  text-align: right;
  padding: 0 20px;
  line-height: 100px;
  color: #fff;
}

.calculator-keys {
  padding: 10px;
  display: grid; 
  grid-template-columns: 1fr 1fr 1fr 1fr; 
  grid-template-rows: 1fr 1fr 1fr 1fr 1fr; 
  gap: 10px 10px; 
  grid-template-areas: 
  "all-clear-btn back-space-btn back-space-btn operator-btn-divide"
  "btnKeyNr7 btnKeyNr8 btnKeyNr9 operator-btn-multiplay"
  "btnKeyNr4 btnKeyNr5 btnKeyNr6 operator-btn-substract"
  "btnKeyNr1 btnKeyNr2 btnKeyNr3 operator-btn-plus"
  "btnKeyNr0 btnKeyNr0 decimal-btn equal-sign-btn"; 
}
  
.operator-btn-divide { grid-area: operator-btn-divide; }
.operator-btn-multiplay { grid-area: operator-btn-multiplay; }
.operator-btn-substract { grid-area: operator-btn-substract; }
.operator-btn-plus { grid-area: operator-btn-plus; }
.equal-sign-btn { grid-area: equal-sign-btn; }
.btnKeyNr7 { grid-area: btnKeyNr7; }
.btnKeyNr8 { grid-area: btnKeyNr8; }
.btnKeyNr9 { grid-area: btnKeyNr9; }
.btnKeyNr4 { grid-area: btnKeyNr4; }
.btnKeyNr5 { grid-area: btnKeyNr5; }
.btnKeyNr6 { grid-area: btnKeyNr6; }
/* .btnKeyNr1 { grid-area: btnKeyNr1; } */
.btnKeyNr2 { grid-area: btnKeyNr2; }
.btnKeyNr3 { grid-area: btnKeyNr3; }
.btnKeyNr0 { grid-area: btnKeyNr0; }
.decimal-btn { grid-area: decimal-btn; }
.all-clear-btn { grid-area: all-clear-btn; }
.back-space-btn { grid-area: back-space-btn; }

button {
  width: 100%;
  height: 100%;
  border: none;
  background: #1e1e1e;
  color: #e6e6e6;
  border-radius: 30px;
  cursor: pointer;
  transition: all 0.2s ease-in-out;
  border-radius: 45px;
}

button:hover,
button:focus {
  background: #aea9a9;
}

.all-clear-btn,
.back-space-btn {
  background:#383838 ;
}

.operator,
.equal-btn {
  font-size: 2em;
  background: #f5980a;
}

.operator:hover,
.operator:focus,
.equal-btn:hover,
.equal-btn:focus {
  background:#9f6003;
}