:root {
    /* Cartoon Color Palette */
    --color-background: linear-gradient(135deg, #FF6B9D 0%, #FFA502 50%, #FFD93D 100%);
    --color-calculator-bg: rgba(255, 240, 220, 0.95);
    --color-display-bg: rgba(255, 255, 240, 0.9);
    --color-button-bg: rgba(255, 200, 100, 0.7);
    --color-button-bg-hover: rgba(255, 180, 60, 0.8);
    
    /* Cartoon Accent Colors */
    --color-operator: #FF1493;
    --color-operator-bg: rgba(255, 20, 147, 0.15);
    --color-operator-bg-hover: rgba(255, 20, 147, 0.3);
    --color-operator-border: rgba(255, 20, 147, 0.5);
    --color-operator-border-hover: rgba(255, 20, 147, 0.8);
    --color-operator-text-hover: #FF1493;
    
    /* Cartoon Text Colors */
    --color-text: #5C3317;
    --color-text-hover: #2C1507;
    --color-text-display: #2C1507;
    
    /* Cartoon Border Colors */
    --color-border: rgba(92, 51, 23, 0.3);
    --color-border-hover: rgba(92, 51, 23, 0.5);
    --color-border-light: rgba(92, 51, 23, 0.2);
    
    /* Cartoon Glass Effect */
    --color-glass-inset: rgba(255, 255, 255, 0.4);
    --color-glass-inset-hover: rgba(255, 255, 255, 0.5);
    --color-operator-inset: rgba(255, 20, 147, 0.15);
    --color-operator-inset-hover: rgba(255, 20, 147, 0.25);
    
    /* Cartoon Shadow Colors */
    --color-shadow: rgba(92, 51, 23, 0.3);
    --color-shadow-dark: rgba(92, 51, 23, 0.5);
    --color-shadow-operator: rgba(255, 20, 147, 0.4);
    
    /* Cartoon Effects */
    --blur-calculator: 0px;
    --blur-display: 0px;
    --blur-button: 0px;
    
    /* Spacing */
    --spacing-base: 20px;
    --spacing-small: 10px;
    --spacing-mobile: 15px;
    
    /* Border Radius - Cartoon Style */
    --radius-large: 40px;
    --radius-medium: 30px;
    
    /* Transitions */
    --transition-default: all 0.3s cubic-bezier(0.34, 1.56, 0.64, 1);
    
    /* Fonts */
    --font-display: 'Righteous', 'Fredoka One', cursive;
    --font-button: 'Fredoka One', 'Bungee', cursive;
    --font-body: 'Fredoka', 'Comic Sans MS', cursive;
}

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

body {
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    background: var(--color-background);
    font-family: var(--font-body);
    position: relative;
    overflow: hidden;
}

/* Cartoon background elements */
body::before {
    content: '';
    position: fixed;
    width: 300px;
    height: 300px;
    background: radial-gradient(circle, rgba(255, 255, 255, 0.1) 0%, transparent 70%);
    border-radius: 50%;
    top: -150px;
    left: -150px;
    pointer-events: none;
    z-index: 0;
}

body::after {
    content: '';
    position: fixed;
    width: 250px;
    height: 250px;
    background: radial-gradient(circle, rgba(255, 255, 255, 0.1) 0%, transparent 70%);
    border-radius: 50%;
    bottom: -125px;
    right: -125px;
    pointer-events: none;
    z-index: 0;
}

.calculator {
    background: var(--color-calculator-bg);
    border-radius: var(--radius-large);
    box-shadow: 
        0 20px 0 rgba(92, 51, 23, 0.3),
        0 30px 30px rgba(92, 51, 23, 0.2),
        inset -5px -5px 0 rgba(0, 0, 0, 0.1),
        inset 5px 5px 0 rgba(255, 255, 255, 0.5);
    padding: var(--spacing-base);
    width: 360px;
    max-width: 95vw;
    border: 4px solid var(--color-border);
    position: relative;
    z-index: 1;
    transform: perspective(1000px) rotateX(0deg);
    transition: var(--transition-default);
}

.calculator:hover {
    transform: perspective(1000px) rotateX(2deg) translateY(-5px);
    box-shadow: 
        0 25px 0 rgba(92, 51, 23, 0.3),
        0 40px 40px rgba(92, 51, 23, 0.3),
        inset -5px -5px 0 rgba(0, 0, 0, 0.1),
        inset 5px 5px 0 rgba(255, 255, 255, 0.5);
}

.display {
    margin-bottom: var(--spacing-base);
    background: var(--color-display-bg);
    border-radius: var(--radius-medium);
    padding: 0;
    overflow: hidden;
    border: 3px solid var(--color-border);
    box-shadow: 
        inset 0 4px 0 rgba(0, 0, 0, 0.1),
        inset 0 -4px 0 rgba(255, 255, 255, 0.4),
        0 8px 0 rgba(92, 51, 23, 0.2);
    position: relative;
}

#display {
    width: 100%;
    padding: var(--spacing-base);
    font-size: 2.8em;
    border: none;
    background: var(--color-display-bg);
    text-align: right;
    font-weight: bold;
    color: var(--color-text-display);
    outline: none;
    border-radius: var(--radius-medium);
    font-family: var(--font-display);
    letter-spacing: 2px;
}

.sound-toggle-container {
    margin-bottom: var(--spacing-small);
    display: flex;
    justify-content: center;
}

.sound-toggle {
    background: linear-gradient(135deg, #FFD700 0%, #FFA500 100%);
    border: 3px solid rgba(255, 165, 0, 0.8);
    border-radius: var(--radius-medium);
    padding: 12px 16px;
    font-size: 1.2em;
    font-weight: 900;
    color: var(--color-text);
    cursor: pointer;
    transition: var(--transition-default);
    font-family: var(--font-button);
    box-shadow: 
        0 8px 0 rgba(92, 51, 23, 0.3),
        inset -2px -2px 0 rgba(0, 0, 0, 0.1),
        inset 2px 2px 0 rgba(255, 255, 255, 0.4);
    text-shadow: 1px 1px 0 rgba(255, 255, 255, 0.5);
    letter-spacing: 1px;
    position: relative;
    top: 0;
}

.sound-toggle:hover {
    background: linear-gradient(135deg, #FFA500 0%, #FF8C00 100%);
    border-color: rgba(255, 165, 0, 1);
    transform: translateY(-3px);
    box-shadow: 
        0 12px 0 rgba(92, 51, 23, 0.3),
        inset -2px -2px 0 rgba(0, 0, 0, 0.1),
        inset 2px 2px 0 rgba(255, 255, 255, 0.4);
    color: var(--color-text-hover);
    filter: brightness(1.1);
}

.sound-toggle:active {
    transform: translateY(5px);
    box-shadow: 
        0 3px 0 rgba(92, 51, 23, 0.3),
        inset -2px -2px 0 rgba(0, 0, 0, 0.1),
        inset 2px 2px 0 rgba(255, 255, 255, 0.4);
}

.sound-toggle.sound-off {
    background: linear-gradient(135deg, #FF6B9D 0%, #FF1493 100%);
    border-color: rgba(255, 20, 147, 0.8);
    color: #fff;
}

.sound-toggle.sound-off:hover {
    background: linear-gradient(135deg, #FF1493 0%, #D1006B 100%);
    border-color: rgba(255, 20, 147, 1);
    filter: brightness(1.1);
}

.buttons {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: var(--spacing-small);
}

.btn {
    padding: var(--spacing-base);
    font-size: 1.3em;
    font-weight: bold;
    border: none;
    border-radius: var(--radius-medium);
    background: var(--color-button-bg);
    color: var(--color-text);
    cursor: pointer;
    transition: var(--transition-default);
    box-shadow: 
        0 8px 0 rgba(92, 51, 23, 0.3),
        inset -2px -2px 0 rgba(0, 0, 0, 0.1),
        inset 2px 2px 0 rgba(255, 255, 255, 0.4);
    border: 2px solid var(--color-border);
    font-family: var(--font-button);
    position: relative;
    top: 0;
    text-shadow: 1px 1px 0 rgba(255, 255, 255, 0.5);
    letter-spacing: 1px;
}

.btn:hover {
    background: var(--color-button-bg-hover);
    transform: translateY(-3px);
    box-shadow: 
        0 12px 0 rgba(92, 51, 23, 0.3),
        inset -2px -2px 0 rgba(0, 0, 0, 0.1),
        inset 2px 2px 0 rgba(255, 255, 255, 0.4);
    color: var(--color-text-hover);
}

.btn:active {
    transform: translateY(5px);
    box-shadow: 
        0 3px 0 rgba(92, 51, 23, 0.3),
        inset -2px -2px 0 rgba(0, 0, 0, 0.1),
        inset 2px 2px 0 rgba(255, 255, 255, 0.4);
}

.btn-operator {
    background: linear-gradient(135deg, rgba(255, 20, 147, 0.2) 0%, rgba(255, 100, 180, 0.2) 100%);
    border-color: var(--color-operator-border);
    color: var(--color-operator);
    font-weight: 900;
    box-shadow: 
        0 8px 0 rgba(255, 20, 147, 0.3),
        inset -2px -2px 0 rgba(0, 0, 0, 0.15),
        inset 2px 2px 0 rgba(255, 255, 255, 0.5);
}

.btn-operator:hover {
    background: linear-gradient(135deg, rgba(255, 20, 147, 0.4) 0%, rgba(255, 100, 180, 0.4) 100%);
    border-color: var(--color-operator-border-hover);
    color: var(--color-operator);
    box-shadow: 
        0 12px 0 rgba(255, 20, 147, 0.4),
        inset -2px -2px 0 rgba(0, 0, 0, 0.15),
        inset 2px 2px 0 rgba(255, 255, 255, 0.5);
    transform: translateY(-3px) scale(1.05);
}

.btn-clear {
    background: linear-gradient(135deg, #FFB347 0%, #FFA500 100%);
    border-color: rgba(255, 165, 0, 0.6);
    box-shadow: 
        0 8px 0 rgba(255, 165, 0, 0.3),
        inset -2px -2px 0 rgba(0, 0, 0, 0.1),
        inset 2px 2px 0 rgba(255, 255, 255, 0.4);
}

.btn-clear:hover {
    background: linear-gradient(135deg, #FFA500 0%, #FF8C00 100%);
    border-color: rgba(255, 165, 0, 0.8);
    box-shadow: 
        0 12px 0 rgba(255, 165, 0, 0.4),
        inset -2px -2px 0 rgba(0, 0, 0, 0.1),
        inset 2px 2px 0 rgba(255, 255, 255, 0.4);
}

.btn-equal {
    background: linear-gradient(135deg, #32CD32 0%, #00FF00 100%);
    border-color: rgba(50, 205, 50, 0.6);
    grid-column: span 2;
    font-size: 1.5em;
    color: #1a5c1a;
    box-shadow: 
        0 10px 0 rgba(50, 205, 50, 0.3),
        inset -2px -2px 0 rgba(0, 0, 0, 0.1),
        inset 2px 2px 0 rgba(255, 255, 255, 0.4);
}

.btn-equal:hover {
    background: linear-gradient(135deg, #00FF00 0%, #00CC00 100%);
    border-color: rgba(50, 205, 50, 0.8);
    box-shadow: 
        0 14px 0 rgba(50, 205, 50, 0.4),
        inset -2px -2px 0 rgba(0, 0, 0, 0.1),
        inset 2px 2px 0 rgba(255, 255, 255, 0.4);
    transform: translateY(-3px) scale(1.02);
}

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

/* Responsive design */
@media (max-width: 480px) {
    :root {
        --spacing-base: var(--spacing-mobile);
    }
    
    .calculator {
        width: 90vw;
        padding: var(--spacing-mobile);
        border-radius: 30px;
    }
    
    .btn {
        padding: var(--spacing-mobile);
        font-size: 1.1em;
    }
    
    #display {
        font-size: 2em;
        padding: var(--spacing-mobile);
    }
    
    .sound-toggle {
        padding: 10px 12px;
        font-size: 1em;
    }
}

/* Animation keyframes */
@keyframes bounce {
    0%, 100% { transform: translateY(0); }
    50% { transform: translateY(-10px); }
}

@keyframes wiggle {
    0%, 100% { transform: rotate(0deg); }
    25% { transform: rotate(-1deg); }
    75% { transform: rotate(1deg); }
}

@keyframes pulse {
    0%, 100% { transform: scale(1); }
    50% { transform: scale(1.05); }
}

.btn:active {
    animation: bounce 0.3s ease-out;
}

.sound-toggle:active {
    animation: pulse 0.2s ease-out;
}