:root {
    --primary: #4361ee;
    --secondary: #3a0ca3;
    --accent: #4895ef;
    --light: #f8f9fa;
    --dark: #212529;
    --gray: #6c757d;
    --light-gray: #e9ecef;
}

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background-color: #f5f7fa;
    color: var(--dark);
    line-height: 1.6;
    padding: 20px;
}

.calc-container {
    max-width: 600px;
    margin: 0 auto;
    background: white;
    border-radius: 12px;
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.1);
    padding: 30px;
    animation: fadeIn 0.5s ease-out;
}
 .container {
            max-width: 600px;
            margin: 0 auto;
            background: white;
            border-radius: 12px;
            box-shadow: 0 5px 15px rgba(0, 0, 0, 0.1);
            padding: 30px;
            animation: fadeIn 0.5s ease-out;}
@keyframes fadeIn {
    from { opacity: 0; transform: translateY(10px); }
    to { opacity: 1; transform: translateY(0); }
}

.back-button {
    display: inline-flex;
    align-items: center;
    padding: 0.5rem 1rem;
    margin-bottom: 1.5rem;
    background-color: var(--dark);
    color: white;
    border-radius: 5px;
    text-decoration: none;
    transition: all 0.3s ease;
}

.back-button:hover {
    background-color: #2a3a5a;
    transform: translateY(-2px);
}

.back-button i {
    margin-right: 8px;
}

.hidden {
    display: none;
}