:root {
  /* Dark Theme (Default) */
  --bg-color: #3a4764;
  --calc-bg: #232c43;
  --display-bg: #182034;
  --display-text: #ffffff;
  --number-bg: #eae3dc;
  --number-text: #444b5a;
  --number-shadow: #b4a597;
  --operator-bg: #637097;
  --operator-text: #ffffff;
  --operator-shadow: #404e72;
  --special-bg: #d03f2f;
  --special-text: #ffffff;
  --special-shadow: #93261a;
  --reset-bg: #637097;
  --reset-text: #ffffff;
  --reset-shadow: #404e72;
}

[data-theme="light"] {
  --bg-color: #e6e6e6;
  --calc-bg: #ffffff;
  --display-bg: #ededed;
  --display-text: #35352c;
  --number-bg: #e5e4e1;
  --number-text: #35352c;
  --number-shadow: #a69d91;
  --operator-bg: #377f86;
  --operator-text: #ffffff;
  --operator-shadow: #1b5f65;
  --special-bg: #ca5502;
  --special-text: #ffffff;
  --special-shadow: #893901;
  --reset-bg: #377f86;
  --reset-text: #ffffff;
  --reset-shadow: #1b5f65;
}

[data-theme="purple"] {
  --bg-color: #160628;
  --calc-bg: #1d0934;
  --display-bg: #1d0934;
  --display-text: #ffe53d;
  --number-bg: #331c4d;
  --number-text: #ffe53d;
  --number-shadow: #871c9c;
  --operator-bg: #58077d;
  --operator-text: #ffffff;
  --operator-shadow: #bc15f4;
  --special-bg: #00e0d1;
  --special-text: #1b2428;
  --special-shadow: #6cf9f2;
  --reset-bg: #58077d;
  --reset-text: #ffffff;
  --reset-shadow: #bc15f4;
}

* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

body {
  font-family: 'League Spartan', 'Spartan', sans-serif;
  background-color: var(--bg-color);
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  min-height: 100vh;
  padding: 20px;
  transition: background-color 0.3s ease;
}

.header {
  display: flex;
  justify-content: space-between;
  align-items: flex-end;
  width: 100%;
  max-width: 440px;
  color: var(--display-text);
}

.logo {
  font-size: 32px;
  font-weight: bold;
  letter-spacing: -1px;
}

.theme-switcher {
  display: flex;
  flex-direction: column;
  align-items: flex-end;
  gap: 8px;
}

.theme-numbers {
  display: flex;
  gap: 12px;
  font-size: 12px;
  font-weight: bold;
  margin-bottom: 5px;
}

.theme-bottom {
  display: flex;
  align-items: center;
  gap: 15px;
}

.theme-label {
  font-size: 12px;
  text-transform: uppercase;
  letter-spacing: 1px;
  font-weight: bold;
}

.theme-toggle {
  width: 48px;
  height: 18px;
  background: var(--calc-bg);
  border-radius: 9px;
  border: none;
  position: relative;
  cursor: pointer;
  transition: all 0.3s ease;
  padding: 2px;
}

.toggle-slider {
  width: 12px;
  height: 12px;
  background: var(--special-bg);
  border-radius: 50%;
  position: absolute;
  top: 3px;
  left: 3px;
  transition: all 0.3s ease;
  box-shadow: 0 1px 3px rgba(0, 0, 0, 0.2);
}

.theme-toggle[data-theme="light"] .toggle-slider {
  transform: translateX(14px);
}

.theme-toggle[data-theme="purple"] .toggle-slider {
  transform: translateX(28px);
}

.calculator-container {
  /* background: var(--calc-bg); */
  border-radius: 10px;
  padding: 32px;
  box-shadow: 0 8px 20px rgba(0, 0, 0, 00);
  width: 100%;
  max-width: 480px;
  transition: background-color 0.3s ease;
  border: 1px solid rgba(255, 255, 255, 00);
}

.calculator-display {
  background: var(--display-bg);
  color: var(--display-text);
  font-size: 48px;
  font-weight: bold;
  text-align: right;
  padding: 30px 25px;
  border-radius: 10px;
  margin-bottom: 25px;
  min-height: 88px;
  display: flex;
  align-items: center;
  justify-content: flex-end;
  overflow: hidden;
  transition: all 0.3s ease;
  letter-spacing: -1px;
}

.calculator-buttons {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  padding: 20px;
  gap: 18px;
  background: var(--calc-bg);
}

button {
  border: none;
  border-radius: 10px;
  font-size: 32px;
  font-weight: bold;
  padding: 20px 10px;
  cursor: pointer;
  transition: all 0.1s ease;
  font-family: inherit;
  position: relative;
  min-height: 64px;
  width: 100%;
  display: flex;
  align-items: center;
  justify-content: center;
}

button:active {
  transform: translateY(2px);
}

.button-number {
  background: var(--number-bg);
  color: var(--number-text);
  box-shadow: 0 4px 0 var(--number-shadow);
}

.button-number:active {
  box-shadow: 0 2px 0 var(--number-shadow);
}

.button-operator {
  background: var(--operator-bg);
  color: var(--operator-text);
  box-shadow: 0 4px 0 var(--operator-shadow);
}

.button-operator:active {
  box-shadow: 0 2px 0 var(--operator-shadow);
}

.button-del {
  background: var(--operator-bg);
  color: var(--operator-text);
  box-shadow: 0 4px 0 var(--operator-shadow);
  font-size: 20px;
}

.button-del:active {
  box-shadow: 0 2px 0 var(--operator-shadow);
}

.button-reset {
  background: var(--operator-bg);
  color: var(--operator-text);
  box-shadow: 0 4px 0 var(--operator-shadow);
  grid-column: span 2;
  font-size: 20px;
}

.button-reset:active {
  box-shadow: 0 2px 0 var(--operator-shadow);
}

.button-equals {
  background: var(--special-bg);
  color: var(--special-text);
  box-shadow: 0 4px 0 var(--special-shadow);
  grid-column: span 2;
}

.button-equals:active {
  box-shadow: 0 2px 0 var(--special-shadow);
}

@media (max-width: 768px) {
  .calculator-container {
    max-width: 420px;
    padding: 28px;
  }
  
  .calculator-display {
    font-size: 42px;
    padding: 25px 20px;
    min-height: 80px;
  }
  
  button {
    font-size: 28px;
    padding: 18px 8px;
    min-height: 58px;
  }
  
  .button-del, .button-reset {
    font-size: 18px;
  }
  
  .calculator-buttons {
    gap: 16px;
  }
}

@media (max-width: 480px) {
  body {
    padding: 15px;
  }
  
  .header {
    margin-bottom: 25px;
  }
  
  .logo {
    font-size: 28px;
  }
  
  .calculator-container {
    max-width: 100%;
    padding: 24px;
  }
  
  .calculator-display {
    font-size: 36px;
    padding: 20px 15px;
    min-height: 75px;
  }
  
  button {
    font-size: 24px;
    padding: 16px 6px;
    min-height: 52px;
  }
  
  .button-del, .button-reset {
    font-size: 16px;
  }
  
  .calculator-buttons {
    gap: 14px;
  }
  
  .theme-label {
    font-size: 11px;
  }
  
  .theme-numbers {
    font-size: 11px;
  }
}

@media (max-width: 360px) {
  .calculator-container {
    padding: 20px;
  }
  
  .calculator-display {
    font-size: 32px;
    padding: 18px 12px;
    min-height: 70px;
  }
  
  button {
    font-size: 22px;
    padding: 14px 4px;
    min-height: 48px;
  }
  
  .button-del, .button-reset {
    font-size: 14px;
  }
  
  .calculator-buttons {
    gap: 12px;
  }
  
  .logo {
    font-size: 24px;
  }
}

@media (min-width: 769px) {
  .calculator-container {
    max-width: 520px;
    padding: 36px;
  }
  
  .calculator-display {
    font-size: 52px;
    padding: 35px 30px;
    min-height: 95px;
  }
  
  button {
    font-size: 36px;
    padding: 24px 12px;
    min-height: 68px;
  }
  
  .calculator-buttons {
    gap: 22px;
  }
}