:root {
    --dark-gray: #333b33;
    --white: #dce8dc;
    --orange: #f8a929;
    --display: #647d6a;
    --light-gray: #6b6b6b;
}

body {
    background-color: #69d028
}

h1 {
    text-align: center;
    font-family: 'Arial', sans-serif;
    color: black;
    margin-top: 20px;
}

.calculator{
    border: 2px solid black;
    border-radius: 10px;
    box-shadow: 5px 5px 15px rgba(0, 0, 0, 0.3);
    background-color: #3d3a3a;
    width: 500px;
    height: 600px;
    margin: 20px auto;
    padding: 20px;
}

.display {
    background-color: var(--display);
    border-radius: 10px;
    text-align: right;
    font-size: 6rem;
    font-family: 'Segment7', monospace;
    width: 390px;
    height: 100px;
    margin: 0 auto 40px auto;
    padding: 10px;
}

.content {
    background-color: black;
    border-radius: 10px;
    width: 400px;
    height: 450px;
    margin: auto;
    padding: 5px;
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    grid-template-rows: repeat(5, 1fr);
    gap: 10px;
    box-sizing: border-box; 
}

.button {
    border-radius: 50%;
    width: 81px;
    height: 81px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.5em;
}

#divide, #multiply, #subtract, #add, #equals {
    background-color: var(--orange);
    color: var(--white);
    font-size: 2em;
}

.button:hover {
    background-color: var(--orange);
    color: var(--white);
    cursor: pointer;
}

.button:active {
    background-color: var(--white);
    color: black;
    cursor: pointer;
}

#divide:hover, #multiply:hover, #subtract:hover, #add:hover, #equals:hover {
    background-color: var(--dark-gray);
    color: white;
    cursor: pointer;  
}

#divide:active, #multiply:active, #subtract:active, #add:active, #equals:active {
    background-color: var(--orange);
    color: white;
    cursor: pointer;  
}
/*--History Panel--*/
.btn {
  padding: 8px 12px;
  border-radius: 10px;
  border: 1px solid #1f2430;
  background: #151824;
  color: #e9edf5;
  cursor: pointer;
}

.btn:hover {
  background-color: yellow;
  color: black;
}

.btn:active {
  background-color:#151824;
  color: #e9edf5;
}

.btn.small {
  padding: 6px 10px; 
  font-size: 0.9rem;
}

#history-panel {
  max-width: 500px;
  margin: 12px auto;
  background: #141824;
  color: #e9edf5;
  border: 1px solid #1f2430;
  border-radius: 10px;
  padding: 12px;
}

.history-bar { 
  display: flex; 
  align-items: center; 
  gap: 12px; 
}

.history-bar h2 { 
  margin: 0; 
  font-size: 1.1rem; 
}

.history-bar .spacer { 
  flex: 1; 
}

#history-list {
  margin: 10px 0 0;
  padding-left: 20px;
}

#history-list li {
  margin-bottom: 6px;
  font-size: 0.95rem;
}