:root {
    /* Mandatory Palette */
    --primary-color: #3b82f6;
    --secondary-color: #64748b;

    /* Theme & Brand Colors */
    --bg-main: #F8FAFC;
    --bg-white: #ffffff;
    --text-main: #0F172A; /* Slate 900 */
    --text-body: #334155; /* Slate 700 */
    --text-muted: #64748b;
    --text-inverse: #ffffff;
    --accent-green: #10B981; /* Mint touch */
    --border-color: #E2E8F0;
    
    /* Layout & Spacing */
    --container-width: 1280px;
    --header-height: 80px;
    --border-radius-sm: 6px;
    --border-radius-md: 12px;
    --border-radius-lg: 20px;
    --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.05);
    --shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.1), 0 2px 4px -2px rgb(0 0 0 / 0.1);
    --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.1), 0 4px 6px -4px rgb(0 0 0 / 0.1);
    --shadow-xl: 0 20px 25px -5px rgb(0 0 0 / 0.1), 0 8px 10px -6px rgb(0 0 0 / 0.1);

    /* Fonts */
    --font-family: 'Inter', 'Manrope', -apple-system, BlinkMacSystemFont, sans-serif;
}

/* Base Reset & Typography */
*, *::before, *::after {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

body {
    font-family: var(--font-family);
    background-color: var(--bg-main);
    color: var(--text-main);
    line-height: 1.6;
    -webkit-font-smoothing: antialiased;
}

a {
    text-decoration: none;
    color: inherit;
    transition: color 0.3s ease;
}

ul {
    list-style: none;
}

h1, h2, h3, h4, h5, h6 {
    font-weight: 700;
    line-height: 1.2;
    color: var(--text-main);
}

.container {
    max-width: var(--container-width);
    margin: 0 auto;
    padding: 0 24px;
}

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 12px 24px;
    font-weight: 600;
    border-radius: var(--border-radius-sm);
    transition: all 0.3s ease;
    cursor: pointer;
    font-size: 0.95rem;
    border: none;
}

.btn-primary {
    background-color: var(--primary-color);
    color: var(--text-inverse);
    box-shadow: 0 4px 6px -1px rgba(59, 130, 246, 0.4);
}

.btn-primary:hover {
    background-color: #2563EB; /* Darker blue */
    transform: translateY(-1px);
    box-shadow: 0 6px 8px -1px rgba(59, 130, 246, 0.5);
}

.btn-outline {
    background-color: transparent;
    border: 1px solid var(--border-color);
    color: var(--text-main);
}

.btn-outline:hover {
    border-color: var(--text-main);
    background-color: var(--bg-white);
}

.btn-icon {
    margin-left: 8px;
}

/* Header (Sticky & Clean) */
.site-header {
    position: sticky;
    top: 0;
    z-index: 1000;
    background-color: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid var(--border-color);
    height: var(--header-height);
    display: flex;
    align-items: center;
}

.header-inner {
    display: flex;
    justify-content: space-between;
    align-items: center;
    width: 100%;
}

.logo {
    display: flex;
    align-items: center;
    gap: 10px;
    font-size: 1.5rem;
    font-weight: 800;
    color: var(--text-main);
    letter-spacing: -0.5px;
}

.logo-icon {
    width: 32px;
    height: 32px;
    background-color: var(--text-main);
    border-radius: 50%; /* Abstract wheel */
    position: relative;
}

.logo-icon::after {
    content: '';
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    width: 12px;
    height: 12px;
    background-color: var(--primary-color);
    border-radius: 50%;
}

.nav-menu {
    display: flex;
    gap: 32px;
}

.nav-link {
    font-weight: 500;
    color: var(--secondary-color);
    font-size: 0.95rem;
}

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

/* Hero Section (The Engine) */
.hero-section {
    position: relative;
    height: 600px;
    display: flex;
    align-items: center;
    justify-content: center;
    background-image: url('https://images.unsplash.com/photo-1492144534655-ae79c964c9d7?auto=format&fit=crop&w=1920&q=80');
    background-size: cover;
    background-position: center;
    text-align: center;
}

.hero-overlay {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(15, 23, 42, 0.85); /* Deep Night Blue Overlay */
    z-index: 1;
}

.hero-content {
    position: relative;
    z-index: 2;
    width: 100%;
    max-width: 900px;
    padding: 0 20px;
}

.hero-title {
    color: var(--text-inverse);
    font-size: 3rem;
    margin-bottom: 40px;
    font-weight: 800;
    letter-spacing: -1px;
}

/* Search Engine Card */
.search-engine-card {
    background-color: var(--bg-white);
    border-radius: var(--border-radius-md);
    padding: 20px; /* Reduced padding to keep tight */
    box-shadow: var(--shadow-xl);
    text-align: left;
}

.search-tabs {
    display: flex;
    gap: 10px;
    margin-bottom: 20px;
    border-bottom: 1px solid var(--border-color);
    padding-bottom: 10px;
}

.search-tab {
    padding: 8px 16px;
    font-weight: 600;
    color: var(--secondary-color);
    cursor: pointer;
    border-radius: 20px;
    transition: all 0.2s;
}

.search-tab.active {
    background-color: var(--bg-main);
    color: var(--text-main);
}

.search-form {
    display: flex;
    align-items: flex-end; /* Align inputs and button at bottom */
    gap: 16px;
    flex-wrap: wrap;
}

.form-group {
    flex: 1;
    min-width: 120px;
}

.form-label {
    display: block;
    font-size: 0.8rem;
    font-weight: 600;
    color: var(--secondary-color);
    margin-bottom: 6px;
    text-transform: uppercase;
}

.form-select {
    width: 100%;
    padding: 12px;
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius-sm);
    background-color: var(--bg-white);
    color: var(--text-main);
    font-size: 1rem;
    outline: none;
    transition: border-color 0.2s;
}

.form-select:focus {
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(59, 130, 246, 0.1);
}

.search-btn-wrapper {
    flex: 0 0 auto;
}

/* Zone de Réassurance (Trust Bar) */
.trust-bar {
    background-color: #F1F5F9;
    padding: 30px 0;
    border-bottom: 1px solid var(--border-color);
}

.trust-inner {
    display: flex;
    align-items: center;
    justify-content: space-between;
    flex-wrap: wrap;
    gap: 20px;
}

.trust-text {
    font-weight: 600;
    color: var(--secondary-color);
    font-size: 0.9rem;
    white-space: nowrap;
}

.trust-logos {
    display: flex;
    align-items: center;
    gap: 40px;
    flex-wrap: wrap;
    justify-content: center;
}

.brand-logo {
    height: 30px;
    filter: grayscale(100%);
    opacity: 0.6;
    transition: all 0.3s;
}

.brand-logo:hover {
    filter: grayscale(0%);
    opacity: 1;
}

/* pSEO Hubs (Data Grid) */
.pseo-section {
    padding: 80px 0;
}

.section-header {
    margin-bottom: 40px;
}

.section-title {
    font-size: 2rem;
    margin-bottom: 10px;
}

.section-subtitle {
    color: var(--secondary-color);
}

.dimensions-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(140px, 1fr));
    gap: 16px;
}

.dimension-pill {
    display: flex;
    align-items: center;
    justify-content: center;
    background-color: var(--bg-white);
    border: 1px solid var(--border-color);
    padding: 12px;
    border-radius: var(--border-radius-sm);
    color: var(--text-main);
    font-weight: 500;
    font-family: monospace; /* Data look */
    font-size: 0.95rem;
    transition: all 0.2s ease;
    cursor: pointer;
}

.dimension-pill:hover {
    border-color: var(--primary-color);
    color: var(--primary-color);
    box-shadow: var(--shadow-sm);
    transform: translateY(-2px);
}

/* Editorial Section (B2B/Media) */
.editorial-section {
    padding: 80px 0;
    background-color: var(--bg-white);
}

.cards-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 32px;
}

.article-card {
    background-color: var(--bg-white);
    border-radius: var(--border-radius-md);
    overflow: hidden;
    border: 1px solid var(--border-color);
    transition: all 0.3s ease;
    display: flex;
    flex-direction: column;
}

.article-card:hover {
    box-shadow: var(--shadow-lg);
    transform: translateY(-4px);
}

.card-image {
    height: 200px;
    background-color: var(--secondary-color);
    position: relative;
    overflow: hidden;
}

.card-image img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: transform 0.5s ease;
}

.article-card:hover .card-image img {
    transform: scale(1.05);
}

.card-content {
    padding: 24px;
    flex: 1;
    display: flex;
    flex-direction: column;
}

.card-tag {
    display: inline-block;
    padding: 4px 10px;
    background-color: rgba(16, 185, 129, 0.1); /* Mint green subtle */
    color: #059669; /* Darker green text */
    font-size: 0.75rem;
    font-weight: 700;
    border-radius: 4px;
    margin-bottom: 12px;
    align-self: flex-start;
    text-transform: uppercase;
}

.card-title {
    font-size: 1.25rem;
    margin-bottom: 12px;
    line-height: 1.4;
}

.card-excerpt {
    color: var(--secondary-color);
    font-size: 0.95rem;
    margin-bottom: 20px;
}

.card-link {
    margin-top: auto;
    color: var(--primary-color);
    font-weight: 600;
    font-size: 0.9rem;
    display: flex;
    align-items: center;
}

.card-link::after {
    content: '→';
    margin-left: 6px;
    transition: margin 0.2s;
}

.article-card:hover .card-link::after {
    margin-left: 10px;
}

/* Footer (SEO Footer) */
.site-footer {
    background-color: var(--text-main);
    color: var(--text-inverse);
    padding: 80px 0 40px;
}

.footer-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 40px;
    margin-bottom: 60px;
    border-bottom: 1px solid rgba(255, 255, 255, 0.1);
    padding-bottom: 60px;
}

.footer-col h4 {
    color: var(--text-inverse);
    margin-bottom: 24px;
    font-size: 1.1rem;
}

.footer-links li {
    margin-bottom: 12px;
}

.footer-links a {
    color: var(--secondary-color); /* Steel gray on dark bg */
    font-size: 0.95rem;
}

.footer-links a:hover {
    color: var(--primary-color);
    padding-left: 4px;
}

.footer-bottom {
    display: flex;
    justify-content: space-between;
    align-items: center;
    color: var(--secondary-color);
    font-size: 0.85rem;
    flex-wrap: wrap;
    gap: 20px;
}

/* Responsive adjustments */
@media (max-width: 768px) {
    .nav-menu {
        display: none; /* Mobile menu would be toggled here */
    }
    
    .hero-title {
        font-size: 2rem;
    }
    
    .search-form {
        flex-direction: column;
        align-items: stretch;
    }
    
    .trust-inner {
        justify-content: center;
        text-align: center;
    }
    
    .trust-logos {
        gap: 20px;
    }
}