:root {
    --primary-color: green; /* Green */
    --secondary-color: #2b6cb0; /* Blue */
    --background-light: #f0fff4;
    --background-dark: #e6fffa;
    --text-dark: #2d3748;
    --highlight: #4fd1c5;
}

body {
    background: linear-gradient(135deg, var(--background-light), var(--background-dark));
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    color: var(--text-dark);
    min-height: 100vh;
}

.header-bg {
    background: linear-gradient(120deg, var(--primary-color), var(--secondary-color));
}

.card {
    border-radius: 16px;
    box-shadow: 0 10px 25px rgba(0, 0, 0, 0.1);
    backdrop-filter: blur(5px);
    background: rgba(255, 255, 255, 0.9);
    transition: transform 0.3s, box-shadow 0.3s;
}

.card:hover {
    transform: translateY(-5px);
    box-shadow: 0 15px 30px rgba(0, 0, 0, 0.15);
}

.calculator-card {
    border-top: 5px solid var(--primary-color);
}

.results-card {
    border-top: 5px solid var(--secondary-color);
}

.info-card {
    border-top: 5px solid var(--highlight);
}

.btn-primary {
    background: linear-gradient(to right, var(--primary-color), var(--secondary-color));
    transition: transform 0.3s, box-shadow 0.3s;
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 5px 15px rgba(59, 130, 246, 0.3);
}

input[type="range"] {
    -webkit-appearance: none;
    height: 8px;
    background: linear-gradient(to right, var(--primary-color), var(--secondary-color));
    border-radius: 5px;
    outline: none;
}

input[type="range"]::-webkit-slider-thumb {
    -webkit-appearance: none;
    width: 20px;
    height: 20px;
    background: white;
    border: 3px solid var(--primary-color);
    border-radius: 50%;
    cursor: pointer;
}

.range-value {
    position: relative;
    display: inline-block;
}

.svg-background {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: -1;
    opacity: 0.05;
}

/* Animation classes */
.fadeIn {
    opacity: 0;
    transform: translateY(20px);
}

.formula-highlight {
    background: linear-gradient(120deg, rgba(56, 178, 172, 0.2), rgba(43, 108, 176, 0.2));
    padding: 2px 6px;
    border-radius: 4px;
    font-family: 'Courier New', monospace;
    font-weight: bold;
}

/* Custom tooltip style */
.custom-tooltip {
    background: rgba(255, 255, 255, 0.95);
    border-radius: 8px;
    box-shadow: 0 4px 10px rgba(0, 0, 0, 0.1);
    padding: 10px;
    border-left: 4px solid var(--primary-color);
    font-size: 14px;
}

/* Progress bar styling */
.progress-container {
    height: 8px;
    background-color: #e2e8f0;
    border-radius: 4px;
    margin: 15px 0;
    overflow: hidden;
}

.progress-bar {
    height: 100%;
    background: linear-gradient(90deg, var(--primary-color), var(--secondary-color));
    border-radius: 4px;
    width: 0%;
    transition: width 1s ease;
}

/* Vector graphics */
.vector-decoration {
    position: absolute;
    z-index: -1;
    opacity: 0.1;
}