:root {
    --primary: #004d40;     /* Deep Green */
    --secondary: #00695c;   /* Teal Green */
    --accent: #ff6f00;      /* Amber/Orange */
    --bg: #f4f6f8;
    --white: #ffffff;
    --text-main: #263238;
    --border: #cfd8dc;
}

* { margin: 0; padding: 0; box-sizing: border-box; font-family: 'Segoe UI', Arial, sans-serif; }
body { background-color: var(--bg); color: var(--text-main); padding-top: 60px; /* Fixed Menu র জন্য জায়গা ছাড়া হলো */ }
a { text-decoration: none; color: inherit; transition: 0.3s; }

/* --- FIXED RESPONSIVE HEADER --- */
.navbar {
    background-color: var(--primary);
    color: var(--white);
    height: 60px;
    position: fixed; /* Fixed Position */
    top: 0;
    left: 0;
    width: 100%;
    z-index: 1000;
    box-shadow: 0 2px 5px rgba(0,0,0,0.1);
}

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
    height: 100%;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo { font-size: 1.3rem; font-weight: bold; text-transform: uppercase; letter-spacing: 1px; color: #fff; }

.nav-links { display: flex; gap: 25px; }
.nav-links a { font-size: 0.95rem; font-weight: 500; color: #e0f2f1; padding: 5px 0; }
.nav-links a:hover { color: var(--accent); }

/* Hamburger Menu (Mobile) */
.menu-toggle { display: none; font-size: 1.5rem; cursor: pointer; color: white; }

/* Mobile Responsive CSS */
@media (max-width: 768px) {
    .menu-toggle { display: block; }
    
    .nav-links {
        display: none; /* Hide by default */
        position: absolute;
        top: 60px;
        left: 0;
        width: 100%;
        background-color: var(--primary);
        flex-direction: column;
        padding: 20px;
        gap: 15px;
        border-top: 1px solid rgba(255,255,255,0.1);
        box-shadow: 0 5px 5px rgba(0,0,0,0.1);
    }
    
    .nav-links.active { display: flex; } /* JS দিয়ে ক্লাস এড হবে */
    .nav-links a { display: block; width: 100%; border-bottom: 1px solid rgba(255,255,255,0.05); padding-bottom: 10px; }
}

/* --- FOOTER CSS --- */
.footer {
    background-color: #263238;
    color: #b0bec5;
    padding: 50px 20px 20px;
    margin-top: 50px;
}
.footer-content {
    max-width: 1200px;
    margin: 0 auto;
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 30px;
}
.footer h3 { color: var(--white); margin-bottom: 20px; font-size: 1.1rem; border-left: 3px solid var(--accent); padding-left: 10px; }
.footer ul { list-style: none; }
.footer ul li { margin-bottom: 10px; }
.footer ul li a:hover { color: var(--accent); padding-left: 5px; }
.copyright { text-align: center; margin-top: 40px; border-top: 1px solid #37474f; padding-top: 20px; font-size: 0.85rem; }