/**
 * SYEL Expertise - E-commerce Landing Page
 * Stylesheet principale
 */

/* ============================================
   VARIABLES CSS
============================================ */
:root {
    /* Couleurs */
    --color-primary: #2C3E50;        /* Bleu marine foncé */
    --color-accent: #3498DB;          /* Bleu clair */
    --color-neutral: #F8F9FA;         /* Fond sections alternées */
    --color-text: #333333;            /* Texte principal */
    --color-white: #FFFFFF;           /* Blanc */
    --color-gray-light: #E8EAED;      /* Gris clair */
    --color-gray: #6C757D;            /* Gris moyen */
    --color-success: #28A745;         /* Vert succès */
    --color-error: #DC3545;           /* Rouge erreur */
    
    /* Typographie */
    --font-heading: 'Montserrat', sans-serif;
    --font-body: 'Open Sans', sans-serif;
    
    /* Espacements */
    --spacing-xs: 0.5rem;   /* 8px */
    --spacing-sm: 1rem;     /* 16px */
    --spacing-md: 1.5rem;   /* 24px */
    --spacing-lg: 2rem;     /* 32px */
    --spacing-xl: 3rem;     /* 48px */
    --spacing-xxl: 4rem;    /* 64px */
    
    /* Transitions */
    --transition: 300ms ease;
    
    /* Ombres */
    --shadow-sm: 0 2px 4px rgba(0,0,0,0.1);
    --shadow-md: 0 4px 12px rgba(0,0,0,0.15);
    --shadow-lg: 0 8px 24px rgba(0,0,0,0.2);
    
    /* Border radius */
    --radius-sm: 4px;
    --radius-md: 8px;
    --radius-lg: 12px;
    --radius-xl: 20px;
}

/* ============================================
   RESET & BASE
============================================ */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
    font-size: 16px;
}

body {
    font-family: var(--font-body);
    color: var(--color-text);
    line-height: 1.6;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

img {
    max-width: 100%;
    height: auto;
    display: block;
}

a {
    text-decoration: none;
    color: inherit;
    transition: var(--transition);
}

ul {
    list-style: none;
}

button {
    border: none;
    background: none;
    cursor: pointer;
    font-family: inherit;
}

/* ============================================
   UTILITAIRES
============================================ */
.container {
    width: 100%;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--spacing-md);
}

.text-center {
    text-align: center;
}

.section-title {
    font-family: var(--font-heading);
    font-size: 2.5rem;
    font-weight: 700;
    color: var(--color-primary);
    margin-bottom: var(--spacing-md);
}

.section-subtitle {
    font-size: 1.125rem;
    color: var(--color-gray);
    margin-bottom: var(--spacing-xl);
    max-width: 700px;
    margin-left: auto;
    margin-right: auto;
}

.lead {
    font-size: 1.25rem;
    font-weight: 400;
    color: var(--color-gray);
}

.highlight {
    color: var(--color-accent);
    position: relative;
}

/* Animation au scroll */
.fade-in {
    opacity: 0;
    transform: translateY(30px);
    transition: opacity 0.6s ease, transform 0.6s ease;
}

.fade-in.visible {
    opacity: 1;
    transform: translateY(0);
}

/* ============================================
   BOUTONS
============================================ */
.btn {
    display: inline-block;
    padding: 0.875rem 2rem;
    font-family: var(--font-heading);
    font-size: 1rem;
    font-weight: 600;
    text-align: center;
    border-radius: var(--radius-md);
    transition: var(--transition);
    cursor: pointer;
    border: 2px solid transparent;
}

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

.btn-primary:hover {
    background: #2980B9;
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

.btn-secondary {
    background: var(--color-white);
    color: var(--color-accent);
    border-color: var(--color-accent);
}

.btn-secondary:hover {
    background: var(--color-accent);
    color: var(--color-white);
}

.btn-lg {
    padding: 1.125rem 2.5rem;
    font-size: 1.125rem;
}

.btn-block {
    display: block;
    width: 100%;
}

/* ============================================
   HEADER
============================================ */
.header {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    background: var(--color-white);
    z-index: 1000;
    transition: var(--transition);
    box-shadow: var(--shadow-sm);
}

.header.scrolled {
    box-shadow: var(--shadow-md);
}

.header-content {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: var(--spacing-sm) 0;
}

.logo a {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    font-family: var(--font-heading);
    font-weight: 700;
    font-size: 1.25rem;
    color: var(--color-primary);
}

.logo-text {
    display: inline-block;
}

.nav-list {
    display: flex;
    gap: var(--spacing-lg);
}

.nav-link {
    font-family: var(--font-heading);
    font-weight: 600;
    color: var(--color-text);
    position: relative;
}

.nav-link::after {
    content: '';
    position: absolute;
    bottom: -5px;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--color-accent);
    transition: var(--transition);
}

.nav-link:hover::after,
.nav-link.active::after {
    width: 100%;
}

.header-contact {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
}

.header-phone {
    font-weight: 600;
    color: var(--color-primary);
}

.header-phone:hover {
    color: var(--color-accent);
}

.burger-menu {
    display: none;
    flex-direction: column;
    gap: 5px;
    padding: var(--spacing-xs);
}

.burger-menu span {
    width: 25px;
    height: 3px;
    background: var(--color-primary);
    border-radius: 2px;
    transition: var(--transition);
}

/* ============================================
   HERO SECTION
============================================ */
.hero {
    padding: 150px 0 var(--spacing-xxl);
    background: linear-gradient(135deg, #F8F9FA 0%, #FFFFFF 100%);
}

.hero-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--spacing-xl);
    align-items: center;
}

.hero-title {
    font-family: var(--font-heading);
    font-size: 3rem;
    font-weight: 800;
    color: var(--color-primary);
    line-height: 1.2;
    margin-bottom: var(--spacing-md);
}

.hero-subtitle {
    font-size: 1.25rem;
    color: var(--color-gray);
    margin-bottom: var(--spacing-xl);
}

.hero-cta {
    display: flex;
    gap: var(--spacing-md);
    margin-bottom: var(--spacing-xl);
}

.trust-badges {
    display: flex;
    gap: var(--spacing-lg);
    flex-wrap: wrap;
}

.badge {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
}

.badge-icon {
    font-size: 2rem;
}

.badge-text {
    display: flex;
    flex-direction: column;
}

.badge-text strong {
    font-family: var(--font-heading);
    font-size: 1.125rem;
    color: var(--color-primary);
}

.badge-text span {
    font-size: 0.875rem;
    color: var(--color-gray);
}

.hero-placeholder {
    background: var(--color-white);
    border-radius: var(--radius-xl);
    padding: var(--spacing-lg);
    box-shadow: var(--shadow-lg);
}

.hero-placeholder svg {
    width: 100%;
    height: auto;
}

/* ============================================
   AVIS GOOGLE - CAROUSEL
============================================ */
.reviews-section {
    padding: var(--spacing-xxl) 0;
    background: var(--color-white);
    overflow: hidden;
}

.reviews-carousel {
    position: relative;
    overflow: hidden;
    margin-top: var(--spacing-xl);
}

.reviews-track {
    display: flex;
    gap: var(--spacing-lg);
    animation: scroll 30s linear infinite;
}

@keyframes scroll {
    0% {
        transform: translateX(0);
    }
    100% {
        transform: translateX(-50%);
    }
}

.review-card {
    min-width: 400px;
    background: var(--color-neutral);
    padding: var(--spacing-lg);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-sm);
    flex-shrink: 0;
}

.review-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: var(--spacing-md);
}

.google-logo {
    width: 80px;
    height: auto;
}

.stars {
    font-size: 1.25rem;
    color: #FBBC04;
}

.review-text {
    font-size: 1rem;
    color: var(--color-text);
    margin-bottom: var(--spacing-md);
    line-height: 1.6;
}

.review-author {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
}

.author-avatar {
    width: 40px;
    height: 40px;
    border-radius: 50%;
    background: var(--color-accent);
    color: var(--color-white);
    display: flex;
    align-items: center;
    justify-content: center;
    font-family: var(--font-heading);
    font-weight: 700;
    font-size: 1.125rem;
}

.author-info {
    display: flex;
    flex-direction: column;
}

.author-info strong {
    font-weight: 600;
    color: var(--color-primary);
}

.author-info span {
    font-size: 0.875rem;
    color: var(--color-gray);
}

/* ============================================
   PAIN POINTS
============================================ */
.pain-points {
    padding: var(--spacing-xxl) 0;
    background: var(--color-neutral);
}

.pain-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: var(--spacing-lg);
    margin-bottom: var(--spacing-xl);
}

.pain-card {
    background: var(--color-white);
    padding: var(--spacing-lg);
    border-radius: var(--radius-lg);
    text-align: center;
    box-shadow: var(--shadow-sm);
    transition: var(--transition);
}

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

.pain-icon {
    font-size: 3rem;
    margin-bottom: var(--spacing-md);
}

.pain-card h3 {
    font-family: var(--font-heading);
    font-size: 1.25rem;
    color: var(--color-primary);
    margin-bottom: var(--spacing-sm);
}

.pain-card p {
    color: var(--color-gray);
    line-height: 1.6;
}

.cta-center {
    text-align: center;
    margin-top: var(--spacing-xl);
}

/* ============================================
   MÉTHODOLOGIE
============================================ */
.methodology {
    padding: var(--spacing-xxl) 0;
    background: var(--color-white);
}

.steps-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: var(--spacing-xl);
}

.step-card {
    position: relative;
    padding: var(--spacing-xl);
    background: var(--color-neutral);
    border-radius: var(--radius-lg);
    transition: var(--transition);
}

.step-card:hover {
    background: var(--color-white);
    box-shadow: var(--shadow-md);
}

.step-number {
    position: absolute;
    top: -20px;
    left: var(--spacing-lg);
    width: 50px;
    height: 50px;
    background: var(--color-accent);
    color: var(--color-white);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-family: var(--font-heading);
    font-size: 1.5rem;
    font-weight: 700;
    box-shadow: var(--shadow-md);
}

.step-content h3 {
    font-family: var(--font-heading);
    font-size: 1.5rem;
    color: var(--color-primary);
    margin-bottom: var(--spacing-md);
    margin-top: var(--spacing-sm);
}

.step-content p {
    color: var(--color-gray);
    line-height: 1.6;
}

/* ============================================
   AVANTAGES
============================================ */
.advantages {
    padding: var(--spacing-xxl) 0;
    background: var(--color-neutral);
}

.advantages-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: var(--spacing-lg);
}

.advantage-card {
    background: var(--color-white);
    padding: var(--spacing-xl);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-sm);
    transition: var(--transition);
}

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

.advantage-icon {
    margin-bottom: var(--spacing-md);
}

.advantage-card h3 {
    font-family: var(--font-heading);
    font-size: 1.375rem;
    color: var(--color-primary);
    margin-bottom: var(--spacing-md);
}

.advantage-card p {
    color: var(--color-gray);
    line-height: 1.6;
    margin-bottom: var(--spacing-md);
}

.advantage-link {
    color: var(--color-accent);
    font-weight: 600;
    display: inline-flex;
    align-items: center;
    gap: 5px;
}

.advantage-link:hover {
    color: #2980B9;
    gap: 10px;
}

/* ============================================
   PAVÉ PROBLÉMATIQUE
============================================ */
.ecommerce-highlight {
    padding: var(--spacing-xxl) 0;
    background: linear-gradient(135deg, var(--color-primary) 0%, #34495E 100%);
    color: var(--color-white);
}

.highlight-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--spacing-xl);
    align-items: center;
}

.highlight-image svg {
    width: 100%;
    max-width: 400px;
    height: auto;
    margin: 0 auto;
    display: block;
}

.highlight-text h2 {
    font-family: var(--font-heading);
    font-size: 2rem;
    font-weight: 700;
    margin-bottom: var(--spacing-md);
    color: var(--color-white);
}

.highlight-text p {
    font-size: 1.125rem;
    margin-bottom: var(--spacing-md);
    line-height: 1.6;
}

.highlight-text .btn-primary {
    margin-top: var(--spacing-md);
}

/* ============================================
   VISIBILITÉ FINANCES
============================================ */
.finance-visibility {
    padding: var(--spacing-xxl) 0;
    background: var(--color-white);
}

.visibility-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--spacing-xl);
    align-items: center;
}

.visibility-text h2 {
    font-family: var(--font-heading);
    font-size: 2rem;
    font-weight: 700;
    color: var(--color-primary);
    margin-bottom: var(--spacing-md);
}

.visibility-text p {
    font-size: 1.125rem;
    color: var(--color-gray);
    margin-bottom: var(--spacing-md);
    line-height: 1.6;
}

.visibility-text strong {
    color: var(--color-primary);
}

.visibility-image svg {
    width: 100%;
    max-width: 400px;
    height: auto;
    margin: 0 auto;
    display: block;
}

/* ============================================
   À PROPOS
============================================ */
.about {
    padding: var(--spacing-xxl) 0;
    background: var(--color-neutral);
}

.about-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--spacing-xl);
    align-items: center;
}

.about-placeholder {
    background: var(--color-white);
    border-radius: var(--radius-lg);
    padding: var(--spacing-lg);
    box-shadow: var(--shadow-md);
}

.about-placeholder svg {
    width: 100%;
    height: auto;
}

.about-text h2 {
    font-family: var(--font-heading);
    font-size: 2.5rem;
    font-weight: 700;
    color: var(--color-primary);
    margin-bottom: var(--spacing-md);
}

.about-features {
    margin: var(--spacing-xl) 0;
}

.about-features li {
    display: flex;
    align-items: flex-start;
    gap: var(--spacing-md);
    margin-bottom: var(--spacing-md);
    padding: var(--spacing-md);
    background: var(--color-white);
    border-radius: var(--radius-md);
    box-shadow: var(--shadow-sm);
}

.feature-icon {
    font-size: 1.5rem;
    flex-shrink: 0;
}

.about-features strong {
    color: var(--color-primary);
}

/* ============================================
   SERVICES
============================================ */
.services {
    padding: var(--spacing-xxl) 0;
    background: var(--color-white);
}

.services-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: var(--spacing-lg);
}

.service-card {
    position: relative;
    background: var(--color-neutral);
    padding: var(--spacing-xl);
    border-radius: var(--radius-lg);
    text-align: center;
    transition: var(--transition);
    border: 2px solid transparent;
}

.service-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-md);
    border-color: var(--color-accent);
}

.service-highlight {
    background: var(--color-white);
    border-color: var(--color-accent);
}

.service-badge {
    position: absolute;
    top: -12px;
    right: var(--spacing-lg);
    background: var(--color-accent);
    color: var(--color-white);
    padding: 0.375rem 1rem;
    border-radius: 20px;
    font-size: 0.875rem;
    font-weight: 600;
    font-family: var(--font-heading);
}

.service-icon {
    font-size: 3rem;
    margin-bottom: var(--spacing-md);
}

.service-card h3 {
    font-family: var(--font-heading);
    font-size: 1.5rem;
    color: var(--color-primary);
    margin-bottom: var(--spacing-md);
}

.service-card p {
    color: var(--color-gray);
    line-height: 1.6;
    margin-bottom: var(--spacing-md);
}

.service-link {
    color: var(--color-accent);
    font-weight: 600;
    display: inline-flex;
    align-items: center;
    gap: 5px;
}

.service-link:hover {
    color: #2980B9;
    gap: 10px;
}

/* ============================================
   FAQ
============================================ */
.faq {
    padding: var(--spacing-xxl) 0;
    background: var(--color-neutral);
}

.faq-list {
    max-width: 800px;
    margin: 0 auto;
}

.faq-item {
    background: var(--color-white);
    border-radius: var(--radius-md);
    margin-bottom: var(--spacing-md);
    overflow: hidden;
    box-shadow: var(--shadow-sm);
}

.faq-question {
    width: 100%;
    padding: var(--spacing-lg);
    display: flex;
    justify-content: space-between;
    align-items: center;
    font-family: var(--font-heading);
    font-size: 1.125rem;
    font-weight: 600;
    color: var(--color-primary);
    text-align: left;
    transition: var(--transition);
}

.faq-question:hover {
    background: var(--color-neutral);
}

.faq-icon {
    font-size: 1.5rem;
    font-weight: 300;
    color: var(--color-accent);
    transition: var(--transition);
}

.faq-item.active .faq-icon {
    transform: rotate(45deg);
}

.faq-answer {
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.3s ease;
}

.faq-item.active .faq-answer {
    max-height: 500px;
}

.faq-answer p {
    padding: 0 var(--spacing-lg) var(--spacing-lg);
    color: var(--color-gray);
    line-height: 1.6;
}

/* ============================================
   CONTACT
============================================ */
.contact {
    padding: var(--spacing-xxl) 0;
    background: var(--color-white);
}

.contact-wrapper {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--spacing-xl);
    align-items: start;
}

.contact-info h2 {
    font-family: var(--font-heading);
    font-size: 2.5rem;
    font-weight: 700;
    color: var(--color-primary);
    margin-bottom: var(--spacing-md);
}

.contact-lead {
    font-size: 1.125rem;
    color: var(--color-gray);
    margin-bottom: var(--spacing-xl);
    line-height: 1.6;
}

.contact-details {
    margin-bottom: var(--spacing-xl);
}

.contact-item {
    display: flex;
    align-items: flex-start;
    gap: var(--spacing-md);
    margin-bottom: var(--spacing-lg);
    padding: var(--spacing-md);
    background: var(--color-neutral);
    border-radius: var(--radius-md);
}

.contact-item-icon {
    font-size: 1.5rem;
    flex-shrink: 0;
}

.contact-item strong {
    display: block;
    font-family: var(--font-heading);
    font-weight: 600;
    color: var(--color-primary);
    margin-bottom: 0.25rem;
}

.contact-item a {
    color: var(--color-accent);
}

.contact-item a:hover {
    text-decoration: underline;
}

.contact-rating {
    padding: var(--spacing-md);
    background: var(--color-neutral);
    border-radius: var(--radius-md);
    text-align: center;
}

.rating-badge {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: var(--spacing-sm);
    margin-bottom: var(--spacing-sm);
}

.rating-score {
    font-family: var(--font-heading);
    font-size: 2rem;
    font-weight: 700;
    color: var(--color-primary);
}

.rating-stars {
    font-size: 1.5rem;
    color: #FBBC04;
}

.rating-text {
    color: var(--color-gray);
    font-size: 0.875rem;
}

/* Formulaire */
.contact-form-wrapper {
    background: var(--color-neutral);
    padding: var(--spacing-xl);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-md);
}

.contact-form {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-md);
}

.form-row {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--spacing-md);
}

.form-group {
    display: flex;
    flex-direction: column;
}

.form-group input,
.form-group textarea {
    padding: var(--spacing-md);
    border: 2px solid var(--color-gray-light);
    border-radius: var(--radius-md);
    font-family: var(--font-body);
    font-size: 1rem;
    transition: var(--transition);
}

.form-group input:focus,
.form-group textarea:focus {
    outline: none;
    border-color: var(--color-accent);
}

.form-group textarea {
    resize: vertical;
    min-height: 120px;
}

.checkbox-label {
    display: flex;
    align-items: flex-start;
    gap: var(--spacing-sm);
    font-size: 0.875rem;
    color: var(--color-gray);
    cursor: pointer;
}

.checkbox-label input[type="checkbox"] {
    margin-top: 3px;
    flex-shrink: 0;
}

.checkbox-label a {
    color: var(--color-accent);
    text-decoration: underline;
}

/* Alertes */
.alert {
    padding: var(--spacing-md);
    border-radius: var(--radius-md);
    margin-bottom: var(--spacing-md);
    font-weight: 600;
}

.alert-success {
    background: #D4EDDA;
    color: #155724;
    border: 1px solid #C3E6CB;
}

.alert-error {
    background: #F8D7DA;
    color: #721C24;
    border: 1px solid #F5C6CB;
}

/* ============================================
   FOOTER
============================================ */
.footer {
    padding: var(--spacing-xxl) 0 var(--spacing-lg);
    background: var(--color-primary);
    color: var(--color-white);
}

.footer-content {
    display: grid;
    grid-template-columns: 2fr 1fr 1fr;
    gap: var(--spacing-xl);
    margin-bottom: var(--spacing-xl);
}

.footer-logo {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    font-family: var(--font-heading);
    font-weight: 700;
    font-size: 1.25rem;
    margin-bottom: var(--spacing-md);
}

.footer-description {
    color: rgba(255, 255, 255, 0.8);
    margin-bottom: var(--spacing-md);
    line-height: 1.6;
}

.footer-social {
    display: flex;
    gap: var(--spacing-md);
}

.footer-social a {
    width: 40px;
    height: 40px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: rgba(255, 255, 255, 0.1);
    border-radius: 50%;
    transition: var(--transition);
}

.footer-social a:hover {
    background: var(--color-accent);
    transform: translateY(-3px);
}

.footer-col h4 {
    font-family: var(--font-heading);
    font-size: 1.125rem;
    font-weight: 600;
    margin-bottom: var(--spacing-md);
}

.footer-links li,
.footer-contact li {
    margin-bottom: var(--spacing-sm);
}

.footer-links a {
    color: rgba(255, 255, 255, 0.8);
}

.footer-links a:hover {
    color: var(--color-accent);
}

.footer-contact {
    color: rgba(255, 255, 255, 0.8);
}

.footer-contact a {
    color: var(--color-accent);
}

.footer-contact a:hover {
    text-decoration: underline;
}

.footer-contact strong {
    display: block;
    color: var(--color-white);
    margin-bottom: 0.25rem;
}

.footer-bottom {
    padding-top: var(--spacing-lg);
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    text-align: center;
    color: rgba(255, 255, 255, 0.7);
    font-size: 0.875rem;
}

.footer-bottom a {
    color: var(--color-accent);
}

.footer-bottom a:hover {
    text-decoration: underline;
}

/* ============================================
   BOUTON RETOUR EN HAUT
============================================ */
.back-to-top {
    position: fixed;
    bottom: var(--spacing-lg);
    right: var(--spacing-lg);
    width: 50px;
    height: 50px;
    background: var(--color-accent);
    color: var(--color-white);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    box-shadow: var(--shadow-lg);
    opacity: 0;
    visibility: hidden;
    transition: var(--transition);
    z-index: 999;
}

.back-to-top.visible {
    opacity: 1;
    visibility: visible;
}

.back-to-top:hover {
    background: #2980B9;
    transform: translateY(-3px);
}

/* ============================================
   RESPONSIVE
============================================ */

/* Tablette */
@media (max-width: 1024px) {
    .section-title {
        font-size: 2rem;
    }
    
    .hero-title {
        font-size: 2.5rem;
    }
    
    .hero-content,
    .about-content,
    .visibility-content,
    .highlight-content,
    .contact-wrapper {
        grid-template-columns: 1fr;
        gap: var(--spacing-lg);
    }
    
    .footer-content {
        grid-template-columns: 1fr 1fr;
    }
    
    .review-card {
        min-width: 350px;
    }
}

/* Mobile */
@media (max-width: 768px) {
    html {
        font-size: 14px;
    }
    
    .header-content {
        padding: var(--spacing-sm) 0;
    }
    
    .nav {
        position: fixed;
        top: 70px;
        left: 0;
        width: 100%;
        background: var(--color-white);
        padding: var(--spacing-lg);
        box-shadow: var(--shadow-md);
        transform: translateY(-100%);
        opacity: 0;
        visibility: hidden;
        transition: var(--transition);
    }
    
    .nav.active {
        transform: translateY(0);
        opacity: 1;
        visibility: visible;
    }
    
    .nav-list {
        flex-direction: column;
        gap: var(--spacing-md);
    }
    
    .header-contact {
        display: none;
    }
    
    .burger-menu {
        display: flex;
    }
    
    .burger-menu.active span:nth-child(1) {
        transform: rotate(45deg) translate(8px, 8px);
    }
    
    .burger-menu.active span:nth-child(2) {
        opacity: 0;
    }
    
    .burger-menu.active span:nth-child(3) {
        transform: rotate(-45deg) translate(7px, -7px);
    }
    
    .hero {
        padding: 120px 0 var(--spacing-xl);
    }
    
    .hero-title {
        font-size: 2rem;
    }
    
    .hero-subtitle {
        font-size: 1rem;
    }
    
    .hero-cta {
        flex-direction: column;
    }
    
    .trust-badges {
        flex-direction: column;
        gap: var(--spacing-md);
    }
    
    .section-title {
        font-size: 1.75rem;
    }
    
    .pain-grid,
    .steps-grid,
    .advantages-grid,
    .services-grid {
        grid-template-columns: 1fr;
    }
    
    .form-row {
        grid-template-columns: 1fr;
    }
    
    .footer-content {
        grid-template-columns: 1fr;
        gap: var(--spacing-lg);
    }
    
    .review-card {
        min-width: 300px;
    }
    
    .logo-text {
        display: none;
    }
}

@media (max-width: 480px) {
    .review-card {
        min-width: 280px;
    }
    
    .btn {
        padding: 0.75rem 1.5rem;
        font-size: 0.875rem;
    }
    
    .btn-lg {
        padding: 1rem 2rem;
        font-size: 1rem;
    }
}