:root {
    /* Design System Colors */
    --primary-blue: #0A2540;
    --energy-green: #00D084;
    --premium-gold: #C5A065;
    --ui-bg: #F4F5F7;
    --ui-gray: #6B7280;
    --white: #FFFFFF;

    /* Typography */
    --font-ar: 'Cairo', sans-serif;
    --font-en: 'Inter', sans-serif;
}

/* Dark Mode Colors */
.dark-mode {
    --primary-blue: #E8F0FE;
    --energy-green: #00FFA3;
    --premium-gold: #D4AF7D;
    --ui-bg: #1A1D23;
    --ui-gray: #A0A0A0;
    --white: #2A2E36;
}

/* Base & Reset */
* { margin: 0; padding: 0; box-sizing: border-box; }
body {
    font-family: var(--font-ar);
    background-color: var(--ui-bg);
    color: var(--primary-blue);
    line-height: 1.6;
    overflow-x: hidden;
}
html[lang="en"] body { font-family: var(--font-en); }

.container { max-width: 1200px; margin: 0 auto; padding: 0 20px; }
a { text-decoration: none; color: inherit; }
ul { list-style: none; }

/* Header */
.main-header {
    background-color: var(--white);
    box-shadow: 0 2px 10px rgba(0,0,0,0.05);
    position: sticky;
    top: 0;
    z-index: 1000;
}
.main-header .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 80px;
}
.logo { font-size: 24px; font-weight: 800; color: var(--primary-blue); }
.logo span { color: var(--energy-green); }

.main-nav ul { display: flex; gap: 30px; }
.main-nav a { font-weight: 600; transition: color 0.3s; }
.main-nav a:hover { color: var(--energy-green); }
.main-nav a.active { color: var(--energy-green); position: relative; }
.main-nav a.active::after {
    content: '';
    position: absolute;
    bottom: -5px;
    left: 0;
    width: 100%;
    height: 2px;
    background: var(--energy-green);
}

.header-actions { display: flex; align-items: center; gap: 15px; }
.btn-theme {
    background: none; border: 1px solid var(--primary-blue); 
    padding: 5px 12px; border-radius: 4px; cursor: pointer; font-size: 1.2rem;
    transition: 0.3s;
}
.btn-theme:hover { background: var(--primary-blue); }
.btn-lang {
    background: none; border: 1px solid var(--primary-blue); 
    padding: 5px 15px; border-radius: 4px; cursor: pointer; font-weight: 600;
    transition: 0.3s;
}
.btn-lang:hover { background: var(--primary-blue); color: var(--white); }

.mobile-toggle {
    display: none;
    background: none;
    border: none;
    font-size: 1.5rem;
    cursor: pointer;
    color: var(--primary-blue);
}

/* Mobile Sidebar Navigation */
.mobile-sidebar {
    position: fixed;
    top: 0;
    width: 280px;
    height: 100vh;
    background: var(--white);
    box-shadow: 0 0 20px rgba(0, 0, 0, 0.2);
    z-index: 2000;
    transition: transform 0.3s ease;
    padding: 20px;
    overflow-y: auto;
}

html[dir="rtl"] .mobile-sidebar {
    right: -280px;
}

html[dir="ltr"] .mobile-sidebar {
    left: -280px;
}

.mobile-sidebar.active {
    transform: translateX(0);
}

html[dir="rtl"] .mobile-sidebar.active {
    right: 0;
}

html[dir="ltr"] .mobile-sidebar.active {
    left: 0;
}

.mobile-sidebar-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 30px;
    padding-bottom: 20px;
    border-bottom: 1px solid var(--ui-bg);
}

.mobile-sidebar-close {
    background: none;
    border: none;
    font-size: 1.5rem;
    cursor: pointer;
    color: var(--primary-blue);
}

.mobile-nav {
    display: flex;
    flex-direction: column;
    gap: 5px;
}

.mobile-nav a {
    padding: 15px;
    border-radius: 8px;
    transition: 0.3s;
    font-weight: 600;
}

.mobile-nav a:hover {
    background: var(--ui-bg);
    color: var(--energy-green);
}

.mobile-nav a.active {
    background: var(--energy-green);
    color: var(--primary-blue);
}

.mobile-sidebar-actions {
    margin-top: 30px;
    padding-top: 20px;
    border-top: 1px solid var(--ui-bg);
    display: flex;
    flex-direction: column;
    gap: 15px;
}

.mobile-sidebar-actions .btn-primary {
    text-align: center;
}

/* Overlay */
.mobile-overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.5);
    z-index: 1500;
    opacity: 0;
    visibility: hidden;
    transition: 0.3s;
}

.mobile-overlay.active {
    opacity: 1;
    visibility: visible;
}

/* Responsive */
@media (max-width: 768px) {
    .main-nav { display: none; }
    .mobile-toggle { display: block; }
    .header-actions .btn-primary { display: none; }
}

/* Buttons */
.btn-primary {
    background-color: var(--energy-green); color: var(--primary-blue);
    padding: 10px 24px; border-radius: 6px; font-weight: 700;
    transition: transform 0.2s, box-shadow 0.2s;
}
.btn-primary:hover { transform: translateY(-2px); box-shadow: 0 4px 12px rgba(0, 208, 132, 0.4); }

.btn-outline {
    border: 2px solid var(--white); color: var(--white);
    padding: 10px 24px; border-radius: 6px; font-weight: 700;
    transition: 0.3s;
}
.btn-outline:hover { background: var(--white); color: var(--primary-blue); }

/* Hero Section */
.hero {
    height: 90vh;
    background: url('https://images.unsplash.com/photo-1508518057-2b288e9b4b6b?q=80&w=2070') center/cover no-repeat;
    position: relative;
    display: flex; align-items: center;
}
.hero-overlay { position: absolute; inset: 0; background: rgba(10, 37, 64, 0.85); }
.hero-content { position: relative; z-index: 2; color: var(--white); max-width: 800px; }
.hero h1 { font-size: 3.5rem; line-height: 1.2; margin-bottom: 20px; }
.hero p { font-size: 1.2rem; margin-bottom: 40px; color: rgba(255,255,255,0.9); }
.hero-cta { display: flex; gap: 20px; }

/* Sectors Section */
.sectors-section { padding: 100px 0; background: var(--white); }
.section-title { font-size: 2.5rem; margin-bottom: 60px; text-align: center; position: relative; }
.section-title::after { content: ''; display: block; width: 60px; height: 4px; background: var(--energy-green); margin: 15px auto 0; }

.sectors-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(300px, 1fr)); gap: 30px; }
.sector-card {
    background: var(--ui-bg); padding: 40px 30px; border-radius: 12px;
    border-left: 4px solid transparent; transition: 0.4s;
    cursor: pointer;
}
html[lang="en"] .sector-card { border-left: none; border-right: 4px solid transparent; }

.sector-card:hover {
    border-color: var(--energy-green); transform: translateY(-10px);
    box-shadow: 0 15px 30px rgba(0,0,0,0.08);
}
.sector-icon { font-size: 3rem; margin-bottom: 20px; }
.sector-card h3 { font-size: 1.5rem; margin-bottom: 15px; }

/* Stats Section */
.stats-section { padding: 60px 0; background: var(--primary-blue); color: var(--white); }
.stats-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(200px, 1fr)); gap: 40px; text-align: center; }
.stat-item { padding: 20px; }
.stat-number { font-size: 3rem; font-weight: 800; color: var(--energy-green); margin-bottom: 10px; }
.stat-label { font-size: 1.1rem; color: rgba(255,255,255,0.8); }

/* Featured Projects Section */
.featured-projects { padding: 100px 0; background: var(--ui-bg); }
.projects-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(350px, 1fr)); gap: 30px; }
.project-card { background: var(--white); border-radius: 12px; overflow: hidden; box-shadow: 0 4px 20px rgba(0,0,0,0.08); transition: 0.3s; }
.project-card:hover { transform: translateY(-5px); box-shadow: 0 8px 30px rgba(0,0,0,0.12); }
.project-image { height: 200px; background: linear-gradient(135deg, var(--primary-blue), var(--energy-green)); position: relative; display: flex; align-items: center; justify-content: center; }
.project-badge { position: absolute; top: 15px; right: 15px; background: var(--energy-green); color: var(--primary-blue); padding: 5px 15px; border-radius: 20px; font-size: 0.85rem; font-weight: 700; }
html[lang="en"] .project-badge { right: auto; left: 15px; }
.project-content { padding: 30px; }
.project-content h3 { font-size: 1.4rem; margin-bottom: 15px; color: var(--primary-blue); }
.project-content p { color: var(--ui-gray); margin-bottom: 20px; line-height: 1.6; }
.project-meta { display: flex; gap: 20px; margin-bottom: 20px; font-size: 0.9rem; color: var(--ui-gray); }
.btn-link { color: var(--energy-green); font-weight: 700; text-decoration: none; transition: 0.3s; }
.btn-link:hover { color: var(--primary-blue); }

/* News Section */
.news-section { padding: 100px 0; background: var(--white); }
.news-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(300px, 1fr)); gap: 30px; }
.news-card { padding: 30px; border-right: 3px solid var(--energy-green); background: var(--ui-bg); border-radius: 8px; transition: 0.3s; }
html[lang="en"] .news-card { border-right: none; border-left: 3px solid var(--energy-green); }
.news-card:hover { background: var(--white); box-shadow: 0 4px 15px rgba(0,0,0,0.08); }
.news-date { color: var(--premium-gold); font-weight: 700; margin-bottom: 10px; font-size: 0.9rem; }
.news-card h3 { font-size: 1.2rem; margin-bottom: 15px; color: var(--primary-blue); }
.news-card p { color: var(--ui-gray); margin-bottom: 15px; line-height: 1.6; }

/* CTA Section */
.cta-section { padding: 100px 0; background: linear-gradient(135deg, var(--primary-blue), #0A3A5C); color: var(--white); text-align: center; }
.cta-content h2 { font-size: 2.5rem; margin-bottom: 20px; }
.cta-content p { font-size: 1.2rem; margin-bottom: 40px; color: rgba(255,255,255,0.9); }
.cta-buttons { display: flex; gap: 20px; justify-content: center; }
.cta-buttons .btn-outline { border-color: var(--white); }

/* Synergy Section */
.synergy-section { padding: 100px 0; background: var(--primary-blue); color: var(--white); }
.synergy-section .container { display: flex; align-items: center; gap: 60px; }
.synergy-content { flex: 1; }
.synergy-visual { flex: 1; background: rgba(255,255,255,0.1); height: 400px; display: flex; align-items: center; justify-content: center; border-radius: 12px; }
.synergy-section .section-title { color: var(--white); text-align: right; }
html[lang="en"] .synergy-section .section-title { text-align: left; }
.synergy-section .section-title::after { margin: 15px 0 0; }
html[lang="en"] .synergy-section .section-title::after { margin: 15px 0 0; }
.synergy-section p { margin-bottom: 30px; color: rgba(255,255,255,0.8); }

/* Footer */
.main-footer { background: #051525; color: rgba(255,255,255,0.5); padding: 60px 0 20px; }
.footer-content { display: grid; grid-template-columns: repeat(auto-fit, minmax(250px, 1fr)); gap: 40px; margin-bottom: 40px; }
.footer-section h4 { color: var(--white); margin-bottom: 20px; font-size: 1.2rem; }
.footer-section p { line-height: 1.6; margin-bottom: 10px; }
.footer-section ul { list-style: none; }
.footer-section ul li { margin-bottom: 10px; }
.footer-section ul li a { color: rgba(255,255,255,0.7); text-decoration: none; transition: 0.3s; }
.footer-section ul li a:hover { color: var(--energy-green); }
.footer-bottom { border-top: 1px solid rgba(255,255,255,0.1); padding-top: 20px; display: flex; justify-content: space-between; align-items: center; }
.footer-bottom p { margin: 0; }
.footer-bottom a { color: rgba(255,255,255,0.7); text-decoration: none; transition: 0.3s; }
.footer-bottom a:hover { color: var(--energy-green); }

/* Mobile Responsive */
@media (max-width: 768px) {
    .main-nav { display: none; } /* Hide for mobile in MVP, toggle with JS */
    .hero h1 { font-size: 2.2rem; }
    .hero-cta { flex-direction: column; }
    .synergy-section .container { flex-direction: column; }
    .synergy-section .section-title { text-align: center; }
    .main-footer .container { flex-direction: column; gap: 10px; }
    .footer-content { grid-template-columns: 1fr; }
    .footer-bottom { flex-direction: column; gap: 10px; text-align: center; }
    .stats-grid { grid-template-columns: repeat(2, 1fr); }
    .projects-grid { grid-template-columns: 1fr; }
    .news-grid { grid-template-columns: 1fr; }
    .cta-buttons { flex-direction: column; }
}

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

.animate-on-scroll {
    opacity: 0;
    transform: translateY(30px);
    transition: opacity 0.6s ease-out, transform 0.6s ease-out;
}

.animate-on-scroll.visible {
    opacity: 1;
    transform: translateY(0);
}

/* Utility Classes */
.text-center { text-align: center; }
.mt-40 { margin-top: 40px; }
.mb-20 { margin-bottom: 20px; }

/* Form Styles */
.form-group { margin-bottom: 20px; }
.form-group label { display: block; margin-bottom: 8px; font-weight: 600; }
.form-group input,
.form-group textarea,
.form-group select {
    width: 100%;
    padding: 12px;
    border: 1px solid #ddd;
    border-radius: 6px;
    font-family: inherit;
    font-size: 1rem;
}
.form-group input:focus,
.form-group textarea:focus,
.form-group select:focus {
    outline: none;
    border-color: var(--energy-green);
    box-shadow: 0 0 0 3px rgba(0, 208, 132, 0.1);
}

/* Social Icons */
.social-icons { display: flex; gap: 15px; }
.social-icon {
    width: 40px;
    height: 40px;
    border-radius: 50%;
    background: var(--primary-blue);
    color: var(--white);
    display: flex;
    align-items: center;
    justify-content: center;
    transition: 0.3s;
}
.social-icon:hover { background: var(--energy-green); }