* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: 'Arial', sans-serif;
    user-select: none;
}

:root {
    --primary-color: #3a4750;
    --secondary-color: #303841;
    --accent-color: #00adb5;
    --light-color: #eeeeee;
    --button-color: #f8f9fa;
    --button-shadow: rgba(0, 0, 0, 0.1);
    --display-shadow: rgba(0, 0, 0, 0.05);
    --text-color: #303841;
    --operator-color: #00adb5;
    --special-color: #ff5722;
}

body {
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    background-color: #f5f5f5;
    overflow: hidden;
}

.calculator-container {
    perspective: 1000px;
    padding: 20px;
}

.calculator {
    width: 350px;
    background-color: white;
    border-radius: 16px;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.1);
    padding: 20px;
    overflow: hidden;
    transform-style: preserve-3d;
    animation: float 6s ease-in-out infinite;
}

@keyframes float {
    0% { transform: translateY(0px); }
    50% { transform: translateY(-8px); }
    100% { transform: translateY(0px); }
}

.display-container {
    background-color: var(--light-color);
    border-radius: 10px;
    padding: 20px;
    margin-bottom: 20px;
    box-shadow: inset 0 2px 5px var(--display-shadow);
    position: relative;
    overflow: hidden;
}

.previous-operand {
    font-size: 1.2rem;
    color: rgba(0, 0, 0, 0.5);
    text-align: right;
    height: 1.5rem;
    overflow: hidden;
    transition: all 0.3s ease;
}

.current-operand {
    font-size: 2.5rem;
    color: var(--text-color);
    text-align: right;
    font-weight: 600;
    overflow: hidden;
    transition: all 0.3s ease;
}

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

button {
    border: none;
    outline: none;
    border-radius: 10px;
    padding: 15px;
    font-size: 1.2rem;
    cursor: pointer;
    transition: all 0.15s ease;
    box-shadow: 0 2px 5px var(--button-shadow);
    position: relative;
    overflow: hidden;
}

button::after {
    content: '';
    position: absolute;
    top: 50%;
    left: 50%;
    width: 5px;
    height: 5px;
    background: rgba(255, 255, 255, 0.5);
    opacity: 0;
    border-radius: 100%;
    transform: scale(1);
    transition: all 0.6s ease;
}

button:active::after {
    transform: scale(20);
    opacity: 0;
    transition: 0s;
}

button:active {
    transform: translateY(1px);
    box-shadow: 0 1px 2px var(--button-shadow);
}

.number-btn {
    background-color: var(--button-color);
    color: var(--text-color);
    font-weight: 500;
}

.number-btn:hover {
    background-color: #f1f3f5;
}

.operator-btn {
    background-color: var(--operator-color);
    color: white;
    font-weight: 600;
}

.operator-btn:hover {
    background-color: #009da5;
}

.special-btn {
    background-color: var(--light-color);
    color: var(--text-color);
    font-weight: 500;
}

.special-btn:hover {
    background-color: #e1e1e1;
}

button[data-action="calculate"] {
    background-color: var(--accent-color);
    color: white;
    font-weight: 600;
}

button[data-action="calculate"]:hover {
    background-color: #009da5;
}

button[data-action="clear"], 
button[data-action="delete"] {
    background-color: var(--special-color);
    color: white;
}

button[data-action="clear"]:hover, 
button[data-action="delete"]:hover {
    background-color: #e64a19;
}

/* Scientific panel styles */
.scientific-panel {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 12px;
    margin-top: 15px;
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.5s cubic-bezier(0.44, 0.05, 0.33, 1);
}

.scientific-panel.visible {
    max-height: 200px;
}

.scientific-btn {
    background-color: #f1f3f5;
    color: var(--text-color);
    font-weight: 500;
}

.scientific-btn:hover {
    background-color: #e9ecef;
}

/* Button press animation */
@keyframes press {
    0% { transform: scale(1); }
    50% { transform: scale(0.95); }
    100% { transform: scale(1); }
}

.btn-pressed {
    animation: press 0.15s ease forwards;
}

/* Result animation */
@keyframes result {
    0% { transform: scale(1); opacity: 1; }
    50% { transform: scale(1.03); opacity: 1; }
    100% { transform: scale(1); opacity: 1; }
}

.result-animation {
    animation: result 0.3s ease forwards;
}

/* Error animation */
@keyframes error {
    0% { transform: translateX(0); }
    25% { transform: translateX(5px); }
    50% { transform: translateX(-5px); }
    75% { transform: translateX(5px); }
    100% { transform: translateX(0); }
}

.error-animation {
    animation: error 0.3s ease forwards;
    color: #e74c3c !important;
}

/* Toggle scientific mode button animation */
#scientific-toggle.active {
    background-color: #00adb5;
    color: white;
}

/* Ripple effect */
.ripple {
    position: absolute;
    border-radius: 50%;
    background: rgba(255, 255, 255, 0.5);
    transform: scale(0);
    animation: ripple 0.6s linear;
}

@keyframes ripple {
    to {
        transform: scale(4);
        opacity: 0;
    }
}