body {
  background: #121212;
  color: white;
  font-family: 'Segoe UI', sans-serif;
  transition: background 0.3s, color 0.3s;
  margin: 0;
  padding: 20px;
  box-sizing: border-box;
}

.theme-toggle {
  text-align: center;
  margin-bottom: 20px;
}

.container {
  display: flex;
  justify-content: center;
  gap: 30px;
  align-items: flex-start;
  flex-wrap: wrap;
}

.calculator {
  width: 300px;
  background: #1f1f1f;
  padding: 20px;
  border-radius: 15px;
  box-shadow: 0 0 15px #00000088;
}

.display {
  background: #000;
  color: #0f0;
  font-size: 2rem;
  text-align: right;
  padding: 15px;
  border-radius: 10px;
  margin-bottom: 20px;
  min-height: 50px;
  word-wrap: break-word;
  user-select: none;
}

.buttons {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 12px;
}

button {
  padding: 15px;
  font-size: 1.2rem;
  border: none;
  border-radius: 10px;
  background: #333;
  color: white;
  cursor: pointer;
  transition: background 0.3s;
}

button:hover {
  background: #444;
}

button.equal {
  grid-column: span 2;
  background: #0a84ff;
}

button.equal:hover {
  background: #0066cc;
}

button.zero {
  grid-column: span 2;
}

.history {
  background: #202020;
  padding: 20px;
  border-radius: 15px;
  width: 280px;
  max-height: 500px;
  overflow-y: auto;
  box-shadow: 0 0 10px #00000055;
}

.history-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 15px;
}

.history-header h3 {
  margin: 0;
  font-size: 1.2rem;
  color: #ddd;
}

#clearHistoryBtn {
  background: crimson;
  color: white;
  border: none;
  padding: 6px 12px;
  border-radius: 6px;
  cursor: pointer;
}

#clearHistoryBtn:hover {
  background: darkred;
}

#historyList {
  list-style: none;
  padding: 0;
  margin: 0;
  color: #ccc;
  font-size: 0.95rem;
}

#historyList li {
  margin-bottom: 8px;
  border-bottom: 1px solid #333;
  padding-bottom: 4px;
}

/* Light Mode */
body.light-mode {
  background: #f0f0f0;
  color: #000;
  
}

/* === Light Mode Button Styling === */
body.light-mode button[data-value="+"],
body.light-mode button[data-value="-"],
body.light-mode button[data-value="*"],
body.light-mode button[data-value="/"],
body.light-mode button[data-value="%"] {
  background: #ff9500;
  color: white;
}
body.light-mode button[data-value="+"]:hover,
body.light-mode button[data-value="-"]:hover,
body.light-mode button[data-value="*"]:hover,
body.light-mode button[data-value="/"]:hover,
body.light-mode button[data-value="%"]:hover {
  background: #e08b00;
}

body.light-mode button[data-value="C"] {
  background: crimson;
  color: white;
}
body.light-mode button[data-value="C"]:hover {
  background: darkred;
}

body.light-mode button[data-value="←"] {
  background: #666;
  color: white;
}
body.light-mode button[data-value="←"]:hover {
  background: #555;
}

body.light-mode button.equal {
  background: #0a84ff;
  color: white;
}
body.light-mode button.equal:hover {
  background: #0066cc;
}

body.light-mode #clearHistoryBtn {
  background: crimson;
  color: white;
}
body.light-mode #clearHistoryBtn:hover {
  background: darkred;
}


body.light-mode .calculator {
  background: #ffffff;
  box-shadow: 0 0 10px #ccc;
}

body.light-mode .display {
  background: #f9f9f9;
  color: black;
}

body.light-mode button {
  background: #e0e0e0;
  color: black;
}

body.light-mode button:hover {
  background: #d0d0d0;
}

body.light-mode .history {
  background: #fafafa;
  color: #000;
}

body.light-mode .history-header h3 {
  color: #333;
}

body.light-mode #clearHistoryBtn {
  background: #666;
}

/* Style for operator buttons */
button[data-value="+"],
button[data-value="-"],
button[data-value="*"],
button[data-value="/"],
button[data-value="%"] {
  background: #ff9500;
  color: white;
}

button[data-value="+"]:hover,
button[data-value="-"]:hover,
button[data-value="*"]:hover,
button[data-value="/"]:hover,
button[data-value="%"]:hover {
  background: #e08b00;
}

/* Operator buttons: + - * / % */
button[data-value="+"],
button[data-value="-"],
button[data-value="*"],
button[data-value="/"],
button[data-value="%"] {
  background: #ff9500;
  color: white;
}
button[data-value="+"]:hover,
button[data-value="-"]:hover,
button[data-value="*"]:hover,
button[data-value="/"]:hover,
button[data-value="%"]:hover {
  background: #e08b00;
}

/* Clear button (C) */
button[data-value="C"] {
  background: crimson;
  color: white;
}
button[data-value="C"]:hover {
  background: darkred;
}

/* Backspace (←) */
button[data-value="←"] {
  background: #666;
  color: white;
}
button[data-value="←"]:hover {
  background: #555;
}

.footer {
  text-align: center;
  margin-top: 1rem;
  font-size: 0.9rem;
  color: rgb(254, 246, 246);
  font-style: italic;
  padding: 0.5rem;
}

body.light-mode .footer {
  color: #c21717;
}

body.dark-mode .footer {
  color: #ffffff;
}