:root {
    --primary: #4A90E2;
    --dark-bg: #101827;
    --card-bg: #1f2937;
    --text-light: #f3f4f6;
    --text-dim: #9ca3af;
}

.menu-toggle {
    font-size: 35px;
}

* { margin: 0; padding: 0; box-sizing: border-box; font-family: 'Segoe UI', sans-serif; }

body { background-color: var(--dark-bg); color: var(--text-light); line-height: 1.6; overflow-x: hidden; }

/* --- Navigation Bar (Matches Electronical) --- */
.navbar {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 20px 3%;
    background: rgba(16, 24, 39, 0.95); /* Deep dark theme */
    position: sticky;
    top: 0;
    z-index: 1000;
    gap: 20px;
    border-bottom: 1px solid rgba(255, 255, 255, 0.1);
}

.logo img {
    height: 60px;
    width: auto;
    transition: transform 0.3s ease;
}

.nav-links {
    display: flex;
    list-style: none;
    gap: 25px;
}

.nav-links a {
    color: var(--text-light);
    text-decoration: none;
    font-weight: 500;
    font-size: 1.1rem;
    transition: color 0.3s;
}

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

/* --- Dropdown Menu & Mobile Toggle --- */
.menu-toggle {
    display: none;
    color: var(--text-light);
    cursor: pointer;
    font-size: 2rem;
}

.dropdown-menu {
    display: none;
    flex-direction: column;
    position: fixed;
    top: 80px;
    left: 0;
    width: 100%;
    background: rgba(16, 24, 39, 0.98);
    padding: 20px;
    z-index: 999;
    border-bottom: 3px solid var(--primary);
}

.dropdown-menu.active {
    display: flex;
}

/* Media Query for Mobile Sync */
@media (max-width: 767px) {
    .nav-links { display: none !important; }
    .menu-toggle { display: block !important; }
}

.dropdown-menu ul {
    list-style: none;
    padding: 20px 5%;
    display: flex;
    flex-direction: column;
    gap: 15px;
    width: 100%;
    align-items: center;
}

.dropdown-menu li {
    padding: 10px 0;
    border-bottom: 1px solid rgba(255, 255, 255, 0.05);
    text-align: center;
}

.dropdown-menu li:last-child {
    border-bottom: none;
}

.dropdown-menu a {
    color: white;
    text-decoration: none;
    font-weight: 500;
    transition: color 0.3s;
    display: block;
    text-align: center;
    font-size: 1.1rem;
}

.dropdown-menu a:hover {
    color: var(--primary);
}

/* Hero Section */
.structural-hero {
    height: 40vh;
    background: linear-gradient(rgba(16, 24, 39, 0.85), rgba(16, 24, 39, 0.85)), url('../Images/Structural2.0.jpg');
    background-size: cover;
    background-position: center;
    display: flex;
    align-items: center;
    justify-content: center;
    text-align: center;
    padding-top: 100px;
    padding-bottom: 100px;
}
.hero-overlay h1 { font-size: 45px; margin-bottom: 15px; color: white; }
.hero-overlay p { max-width: 800px; margin: 0 auto; color: var(--text-dim); font-size: larger; padding: 0 20px;}

/* Container & Rows */
.container { max-width: 1200px; margin: 0 auto; padding: 60px 20px; }

.feature-row {
    display: flex;
    align-items: flex-start;
    gap: 60px;
    margin-bottom: 100px;
}
.feature-row.reverse { flex-direction: row-reverse; }

.feature-text { flex: 1.2; }
.feature-text h2 { font-size: 2.2rem; color: var(--primary); margin-bottom: 20px; }
.feature-text p { margin-bottom: 20px; color: var(--text-dim); }

/* Multi-column list for long lists */
.list-grid { display: flex; gap: 40px; font-size: larger;}
.feature-text ul { list-style: none; flex: 1; }
.feature-text ul li { 
    margin-bottom: 12px; 
    padding-left: 25px; 
    position: relative; 
    color: var(--text-dim);
    font-size: larger;
}
.feature-text ul li::before {
    content: "→";
    position: absolute;
    left: 0;
    color: var(--primary);
}

/* Image Gallery Stack */
.feature-image-gallery { 
    flex: 0.8; 
    display: flex; 
    flex-direction: column; 
    gap: 20px; 
}
.feature-image-gallery img {
    width: 100%;
    border-radius: 15px;
    box-shadow: 0 10px 30px rgba(0,0,0,0.5);
    border: 1px solid rgba(255,255,255,0.1);
    transition: 0.3s;
}
.feature-image-gallery img:hover { transform: scale(1.02); }

/* Button Styling */
.action-footer { text-align: center; margin-top: 40px; font-size: larger; }
.btn-main {
    padding: 15px 40px;
    background: var(--primary);
    color: white;
    text-decoration: none;
    border-radius: 30px;
    font-weight: bold;
    transition: 0.3s;
    display: inline-block;
}
.btn-main:hover { transform: translateY(-3px); box-shadow: 0 10px 20px rgba(74, 144, 226, 0.4); }

/* Responsive */
@media (min-width: 768px) {
    .menu-toggle {
        display: none !important;
    }
    
    .dropdown-menu {
        display: none !important;
    }
    
    .nav-links {
        display: flex !important;
        flex-direction: row !important;
        position: static !important;
        top: auto !important;
        left: auto !important;
        width: auto !important;
        background: none !important;
        flex: none !important;
        gap: 40px;
    }
}

@media (max-width: 767px) {
    .nav-links { display: none; }
    .list-grid { flex-direction: column; gap: 0; }
    .feature-row, .feature-row.reverse { flex-direction: column; }
    .feature-image-gallery { width: 100%; }
}