/* Modern, scalable CSS */
:root {
    --primary: #3b82f6;
    --primary-dark: #2563eb;
    --secondary: #8b5cf6;
    --danger: #ef4444;
    --success: #10b981;
    --gray-50: #f9fafb;
    --gray-100: #f3f4f6;
    --gray-600: #4b5563;
    --gray-900: #111827;
    --shadow: 0 4px 6px -1px rgb(0 0 0 / 0.1);
    --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.1);
}

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

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    line-height: 1.6;
    color: var(--gray-900);
    background: linear-gradient(to bottom, #ffffff, #f9fafb);
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 2rem;
}

/* Header */
.header {
    background: white;
    border-bottom: 1px solid var(--gray-100);
    padding: 1rem 0;
    position: sticky;
    top: 0;
    z-index: 100;
    box-shadow: var(--shadow);
}

.nav {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo {
    font-size: 1.5rem;
    font-weight: bold;
    color: var(--primary);
}

.nav-links {
    display: flex;
    align-items: center;
    gap: 2rem;
}

.nav-links a {
    text-decoration: none;
    color: var(--gray-600);
    transition: color 0.3s;
}

.nav-links a:hover {
    color: var(--primary);
}

/* Hero */
.hero {
    text-align: center;
    padding: 5rem 2rem;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
}

.hero h1 {
    font-size: 3rem;
    margin-bottom: 1rem;
}

.hero p {
    font-size: 1.25rem;
    margin-bottom: 2rem;
    opacity: 0.95;
}

/* Buttons */
.button-group {
    display: flex;
    gap: 1rem;
    justify-content: center;
    flex-wrap: wrap;
}

.btn {
    padding: 0.75rem 2rem;
    border-radius: 0.5rem;
    border: none;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s;
    text-decoration: none;
    display: inline-block;
}

.btn-primary {
    background: var(--primary);
    color: white;
}

.btn-primary:hover {
    background: var(--primary-dark);
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
}

.btn-secondary {
    background: white;
    color: var(--primary);
    border: 2px solid white;
}

.btn-secondary:hover {
    background: rgba(255,255,255,0.9);
}

.btn-gradient {
    background: linear-gradient(135deg, var(--primary), var(--secondary));
    color: white;
}

.btn-small {
    padding: 0.5rem 1rem;
    font-size: 0.875rem;
}

/* Calculator */
.calculator-card {
    background: white;
    border-radius: 1rem;
    padding: 2rem;
    margin: 3rem auto;
    max-width: 800px;
    box-shadow: var(--shadow-lg);
}

.calculator-section {
    margin-top: 2rem;
}

.input-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 1.5rem;
    margin-bottom: 2rem;
}

.input-group label {
    display: block;
    margin-bottom: 0.5rem;
    font-weight: 500;
    color: var(--gray-600);
}

.input-group input {
    width: 100%;
    padding: 0.75rem;
    border: 2px solid var(--gray-100);
    border-radius: 0.5rem;
    font-size: 1rem;
    transition: border-color 0.3s;
}

.input-group input:focus {
    outline: none;
    border-color: var(--primary);
}

/* Results */
.results-box {
    margin-top: 2rem;
    padding: 1.5rem;
    background: var(--gray-50);
    border-radius: 0.75rem;
    animation: fadeIn 0.5s;
}

@keyframes fadeIn {
    from { opacity: 0; transform: translateY(10px); }
    to { opacity: 1; transform: translateY(0); }
}

.result-item {
    display: flex;
    justify-content: space-between;
    padding: 0.75rem 0;
    border-bottom: 1px solid var(--gray-100);
}

.result-item:last-child {
    border-bottom: none;
}

.result-value {
    font-weight: bold;
    font-size: 1.25rem;
}

.risk-high { color: var(--danger); }
.risk-medium { color: #f59e0b; }
.risk-low { color: var(--success); }

/* Premium Teaser */
.premium-teaser {
    margin-top: 2rem;
    padding: 2rem;
    background: linear-gradient(135deg, rgba(59,130,246,0.05), rgba(139,92,246,0.05));
    border-radius: 0.75rem;
    border: 2px dashed var(--primary);
    text-align: center;
}

.premium-teaser h4 {
    margin-bottom: 1rem;
    color: var(--primary);
}

.premium-teaser ul {
    list-style: none;
    margin-bottom: 1.5rem;
}

.premium-teaser li {
    padding: 0.5rem 0;
}

.premium-teaser li:before {
    content: "✓ ";
    color: var(--success);
    font-weight: bold;
}

/* Loading State */
.loading {
    display: inline-block;
    width: 20px;
    height: 20px;
    border: 3px solid var(--gray-100);
    border-top-color: var(--primary);
    border-radius: 50%;
    animation: spin 1s linear infinite;
}

@keyframes spin {
    to { transform: rotate(360deg); }
}

/* Mobile Responsive */
@media (max-width: 768px) {
    .hero h1 {
        font-size: 2rem;
    }
    
    .input-grid {
        grid-template-columns: 1fr;
    }
    
    .nav-links {
        gap: 1rem;
    }
}