:root {
    --primary-blue: #0055FF;
    --secondary-blue: #00A3FF;
    --text-dark: #2D3648;
    --text-muted: #6B7280;
    --input-bg: #F8F9FA;
    --border-color: #E5E5E5;
}

body {
    background: #ffffff;
    color: var(--text-dark);
    font-family: 'Inter', system-ui, -apple-system, sans-serif;
    min-height: 100vh;
    position: relative;
    overflow-x: hidden;
}

/* Decorative elements */
.container::before,
.container::after {
    content: '';
    position: fixed;
    width: 600px;
    height: 600px;
    border-radius: 50%;
    background: linear-gradient(135deg, var(--primary-blue), var(--secondary-blue));
    opacity: 0.03;
    z-index: -1;
    filter: blur(100px);
}

.container::before {
    top: -300px;
    right: -300px;
}

.container::after {
    bottom: -300px;
    left: -300px;
}

.card {
    background: #ffffff;
    border-radius: 16px;
    border: none;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.05);
}

.card-body {
    padding: 2.5rem;
}

.form-control {
    background: var(--input-bg);
    border: 1px solid var(--border-color);
    color: var(--text-dark);
    border-radius: 12px;
    padding: 0.75rem 1rem;
    transition: all 0.3s ease;
}

.form-control::placeholder {
    color: var(--text-muted);
}

.form-control:focus {
    background: var(--input-bg);
    border-color: var(--primary-blue);
    color: var(--text-dark);
    box-shadow: 0 0 0 3px rgba(0, 85, 255, 0.1);
}

.input-group-text {
    background: var(--input-bg);
    border: 1px solid var(--border-color);
    color: var(--text-dark);
    border-radius: 0 12px 12px 0;
}

.btn-primary {
    background: linear-gradient(135deg, var(--primary-blue), var(--secondary-blue));
    border: none;
    padding: 1rem;
    font-weight: 500;
    border-radius: 12px;
    transition: all 0.3s ease;
    color: #ffffff;
}

.btn-primary:hover {
    transform: translateY(-1px);
    box-shadow: 0 4px 12px rgba(0, 85, 255, 0.2);
}

.btn-outline-primary {
    color: var(--text-dark);
    border: 1px solid var(--border-color);
    background: #ffffff;
}

.btn-outline-primary:hover,
.btn-check:checked + .btn-outline-primary {
    background: linear-gradient(135deg, var(--primary-blue), var(--secondary-blue));
    border-color: transparent;
    color: #ffffff;
}

#result {
    border-top: 1px solid var(--border-color);
    margin-top: 2rem;
    padding-top: 2rem;
}

.display-4 {
    font-weight: 700;
    color: var(--primary-blue);
}

.form-label {
    color: var(--text-dark);
    font-size: 0.875rem;
    font-weight: 500;
    margin-bottom: 0.5rem;
}

.text-muted {
    color: var(--text-muted) !important;
}

@media (max-width: 768px) {
    .card-body {
        padding: 1.5rem;
    }
}