/* Reset et variables CSS */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    --primary-color: #253659;
    --primary-dark: #1e2d4a;
    --secondary-color: #64748b;
    --accent-color: #10b981;
    --danger-color: #ef4444;
    --warning-color: #f59e0b;
    --text-dark: #1e293b;
    --text-light: #64748b;
    --bg-light: #f8fafc;
    --bg-white: #ffffff;
    --border-color: #e2e8f0;
    --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.05);
    --shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.1);
    --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.1);
    --border-radius: 12px;
    --transition: all 0.3s ease;
}

body {
    font-family: 'Inter', sans-serif;
    line-height: 1.6;
    color: var(--text-dark);
    background-color: var(--bg-white);
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

/* Header Hero */
.hero {
    background: linear-gradient(135deg, rgba(37, 54, 89, 0.8) 0%, rgba(30, 45, 74, 0.8) 100%), 
                url('https://images.unsplash.com/photo-1560518883-ce09059eeffa?ixlib=rb-4.0.3&auto=format&fit=crop&w=1920&q=80') center/cover;
    color: white;
    padding: 100px 0 80px;
    text-align: center;
    position: relative;
    overflow: hidden;
}

.hero::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: url('data:image/svg+xml,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 100 100"><defs><pattern id="grid" width="10" height="10" patternUnits="userSpaceOnUse"><path d="M 10 0 L 0 0 0 10" fill="none" stroke="rgba(255,255,255,0.1)" stroke-width="1"/></pattern></defs><rect width="100" height="100" fill="url(%23grid)"/></svg>');
    opacity: 0.3;
}

.hero .container {
    position: relative;
    z-index: 1;
}

.hero h1 {
    font-size: 3.5rem;
    font-weight: 700;
    margin-bottom: 20px;
    line-height: 1.2;
}

.hero-subtitle {
    font-size: 1.3rem;
    margin-bottom: 40px;
    opacity: 0.9;
    max-width: 600px;
    margin-left: auto;
    margin-right: auto;
}

.hero-cta {
    display: flex;
    gap: 20px;
    justify-content: center;
    flex-wrap: wrap;
}

/* Boutons */
.btn {
    display: inline-block;
    padding: 15px 30px;
    border-radius: var(--border-radius);
    text-decoration: none;
    font-weight: 600;
    font-size: 1rem;
    transition: var(--transition);
    border: 2px solid transparent;
    cursor: pointer;
    text-align: center;
}

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

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

.btn-secondary {
    background-color: transparent;
    color: white;
    border-color: white;
}

.btn-secondary:hover {
    background-color: white;
    color: var(--primary-color);
    transform: translateY(-2px);
}

/* Navigation sticky */
.sticky-nav {
    background-color: var(--bg-white);
    box-shadow: var(--shadow-md);
    position: sticky;
    top: 0;
    z-index: 100;
}

.sticky-nav ul {
    list-style: none;
    display: flex;
    justify-content: center;
    gap: 40px;
    padding: 20px 0;
}

.sticky-nav a {
    text-decoration: none;
    color: var(--text-dark);
    font-weight: 500;
    transition: var(--transition);
    position: relative;
}

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

.sticky-nav a::after {
    content: '';
    position: absolute;
    bottom: -8px;
    left: 0;
    width: 0;
    height: 2px;
    background-color: var(--primary-color);
    transition: var(--transition);
}

.sticky-nav a:hover::after {
    width: 100%;
}

/* Sections */
.section {
    padding: 80px 0;
}

.section-alt {
    background-color: var(--bg-light);
}

.section-title {
    font-size: 2.5rem;
    font-weight: 700;
    text-align: center;
    margin-bottom: 20px;
    color: var(--text-dark);
}

.section-description {
    text-align: center;
    font-size: 1.2rem;
    color: var(--text-light);
    margin-bottom: 60px;
    max-width: 600px;
    margin-left: auto;
    margin-right: auto;
}

/* Grilles d'avantages */
.advantages-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
    gap: 30px;
    margin-top: 60px;
}

.advantage-card {
    background: var(--bg-white);
    padding: 40px 30px;
    border-radius: var(--border-radius);
    box-shadow: var(--shadow-sm);
    transition: var(--transition);
    border: 1px solid var(--border-color);
}

.advantage-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-lg);
}

.advantage-card .icon {
    width: 60px;
    height: 60px;
    background: linear-gradient(135deg, var(--primary-color), var(--primary-dark));
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: 20px;
    color: white;
    font-size: 1.5rem;
}

.advantage-card h3 {
    font-size: 1.4rem;
    font-weight: 600;
    margin-bottom: 15px;
    color: var(--text-dark);
}

.advantage-card p {
    color: var(--text-light);
    margin-bottom: 20px;
    line-height: 1.6;
}

.advantage-card ul {
    list-style: none;
    padding: 0;
}

.advantage-card li {
    padding: 8px 0;
    color: var(--text-light);
    position: relative;
    padding-left: 25px;
}

.advantage-card li::before {
    content: '✓';
    position: absolute;
    left: 0;
    color: var(--accent-color);
    font-weight: bold;
}

/* Grille d'inconvénients */
.disadvantages-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
    gap: 30px;
    margin-top: 60px;
}

.disadvantage-card {
    background: var(--bg-white);
    padding: 40px 30px;
    border-radius: var(--border-radius);
    box-shadow: var(--shadow-sm);
    transition: var(--transition);
    border: 1px solid var(--border-color);
}

.disadvantage-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-lg);
}

.disadvantage-card .icon {
    width: 60px;
    height: 60px;
    background: linear-gradient(135deg, var(--danger-color), #dc2626);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: 20px;
    color: white;
    font-size: 1.5rem;
}

.disadvantage-card h3 {
    font-size: 1.4rem;
    font-weight: 600;
    margin-bottom: 15px;
    color: var(--text-dark);
}

.disadvantage-card p {
    color: var(--text-light);
    margin-bottom: 20px;
    line-height: 1.6;
}

.disadvantage-card ul {
    list-style: none;
    padding: 0;
}

.disadvantage-card li {
    padding: 8px 0;
    color: var(--text-light);
    position: relative;
    padding-left: 25px;
}

.disadvantage-card li::before {
    content: '⚠';
    position: absolute;
    left: 0;
    color: var(--warning-color);
    font-weight: bold;
}



/* Section Expertise */
.expertise-container {
    display: grid;
    gap: 40px;
    margin-top: 60px;
}

.expertise-card {
    background: var(--bg-white);
    padding: 40px;
    border-radius: var(--border-radius);
    box-shadow: var(--shadow-md);
    border: 1px solid var(--border-color);
}

.expertise-header {
    display: flex;
    align-items: center;
    gap: 20px;
    margin-bottom: 30px;
    padding-bottom: 20px;
    border-bottom: 2px solid var(--primary-color);
}

.expertise-header i {
    font-size: 2rem;
    color: var(--primary-color);
    background: linear-gradient(135deg, var(--primary-color), var(--primary-dark));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.expertise-header h3 {
    font-size: 1.5rem;
    font-weight: 600;
    color: var(--text-dark);
    margin: 0;
}

.comparison-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 30px;
    margin-top: 20px;
}

.comparison-item {
    background: var(--bg-light);
    padding: 25px;
    border-radius: 8px;
    border-left: 4px solid var(--primary-color);
}

.comparison-item h4 {
    font-size: 1.2rem;
    font-weight: 600;
    color: var(--primary-color);
    margin-bottom: 15px;
}

.comparison-item ul {
    list-style: none;
    padding: 0;
}

.comparison-item li {
    padding: 8px 0;
    color: var(--text-light);
    line-height: 1.5;
}

.obligations-content h4 {
    font-size: 1.2rem;
    font-weight: 600;
    color: var(--primary-color);
    margin: 20px 0 10px 0;
}

.obligations-content h4:first-child {
    margin-top: 0;
}

.obligations-content p {
    color: var(--text-light);
    line-height: 1.6;
    margin-bottom: 15px;
}

.risks-content ul {
    list-style: none;
    padding: 0;
    margin-bottom: 25px;
}

.risks-content li {
    padding: 10px 0;
    color: var(--text-light);
    line-height: 1.5;
    border-bottom: 1px solid var(--border-color);
}

.risks-content li:last-child {
    border-bottom: none;
}

.expert-advice {
    background: linear-gradient(135deg, var(--accent-color), #059669);
    color: white;
    padding: 20px;
    border-radius: 8px;
    margin-top: 20px;
}

.expert-advice p {
    margin: 0;
    font-weight: 500;
    line-height: 1.5;
}

/* Calculateur */
.calculator-container {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 60px;
    margin-top: 60px;
    align-items: start;
}

.calculator-inputs {
    background: var(--bg-white);
    padding: 40px;
    border-radius: var(--border-radius);
    box-shadow: var(--shadow-md);
}

.calculator-inputs h3 {
    font-size: 1.5rem;
    font-weight: 600;
    margin-bottom: 30px;
    color: var(--text-dark);
}

.calculator-inputs h4 {
    font-size: 1.2rem;
    font-weight: 600;
    margin: 30px 0 20px;
    color: var(--text-dark);
    border-top: 1px solid var(--border-color);
    padding-top: 20px;
}

.input-group {
    margin-bottom: 25px;
}

.input-group label {
    display: block;
    margin-bottom: 8px;
    font-weight: 500;
    color: var(--text-dark);
}

.input-group input {
    width: 100%;
    padding: 12px 15px;
    border: 2px solid var(--border-color);
    border-radius: 8px;
    font-size: 1rem;
    transition: var(--transition);
    background-color: var(--bg-white);
}

.input-group input:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.1);
}

.calculator-results {
    background: var(--bg-white);
    padding: 40px;
    border-radius: var(--border-radius);
    box-shadow: var(--shadow-md);
    position: sticky;
    top: 120px;
}

.calculator-results h3 {
    font-size: 1.5rem;
    font-weight: 600;
    margin-bottom: 30px;
    color: var(--text-dark);
}

.placeholder-text {
    color: var(--text-light);
    text-align: center;
    font-style: italic;
    padding: 40px 20px;
}

.result-item {
    display: flex;
    justify-content: space-between;
    padding: 15px 0;
    border-bottom: 1px solid var(--border-color);
}

.result-item:last-child {
    border-bottom: none;
    font-weight: 600;
    font-size: 1.1rem;
    margin-top: 10px;
    padding-top: 20px;
    border-top: 2px solid var(--primary-color);
}

.result-label {
    color: var(--text-dark);
}

.result-value {
    font-weight: 600;
    color: var(--primary-color);
}

.result-positive {
    color: var(--accent-color);
}

.result-negative {
    color: var(--danger-color);
}

/* Footer */
.footer {
    background-color: var(--text-dark);
    color: white;
    padding: 60px 0 30px;
}

.footer-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 40px;
    margin-bottom: 40px;
}

.footer-section h4 {
    font-size: 1.2rem;
    font-weight: 600;
    margin-bottom: 20px;
}

.footer-section p {
    color: rgba(255, 255, 255, 0.8);
    line-height: 1.6;
}

.footer-section ul {
    list-style: none;
}

.footer-section ul li {
    margin-bottom: 10px;
}

.footer-section ul li a {
    color: rgba(255, 255, 255, 0.8);
    text-decoration: none;
    transition: var(--transition);
}

.footer-section ul li a:hover {
    color: white;
}

.footer-bottom {
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    padding-top: 30px;
    text-align: center;
    color: rgba(255, 255, 255, 0.6);
}

/* Responsive Design */
@media (max-width: 768px) {
    .hero h1 {
        font-size: 2.5rem;
    }
    
    .hero-subtitle {
        font-size: 1.1rem;
    }
    
    .hero-cta {
        flex-direction: column;
        align-items: center;
    }
    
    .sticky-nav ul {
        flex-direction: column;
        gap: 20px;
        text-align: center;
    }
    
    .advantages-grid,
    .disadvantages-grid {
        grid-template-columns: 1fr;
    }
    
    .comparison-grid {
        grid-template-columns: 1fr;
        gap: 20px;
    }
    

    
    .calculator-container {
        grid-template-columns: 1fr;
        gap: 40px;
    }
    
    .calculator-results {
        position: static;
    }
    
    .container {
        padding: 0 15px;
    }
    
    .section {
        padding: 60px 0;
    }
    
    .section-title {
        font-size: 2rem;
    }
}

@media (max-width: 480px) {
    .hero {
        padding: 80px 0 60px;
    }
    
    .hero h1 {
        font-size: 2rem;
    }
    
    .advantage-card,
    .disadvantage-card {
        padding: 30px 20px;
    }
    
    .calculator-inputs,
    .calculator-results {
        padding: 30px 20px;
    }
}

/* Animations */
@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.advantage-card,
.disadvantage-card {
    animation: fadeInUp 0.6s ease-out;
}

/* Scroll smooth */
html {
    scroll-behavior: smooth;
}