/* Header and navigation styles */
header {
    position: fixed;
    top: 0;
    width: 100%;
    background: #ffffff;
    border-bottom: 1px solid #e5f7eb;
    z-index: 1000;
}

nav {
    display: flex;
    align-items: center;
    max-width: 1400px;
    margin: 0 auto;
    padding: 0.1rem 5%;
}

.nav-left {
    flex: 1;
    display: flex;
    align-items: center;
}

.nav-right {
    flex: 1;
    display: flex;
    align-items: center;
    justify-content: flex-end;
}

.logo {
    font-size: 2.2rem;
    font-family: 'Inter', 'Segoe UI', Arial, sans-serif;
    font-weight: 900;
    color: var(--primary);
    letter-spacing: -1px;
}

.logo .ai {
    background: linear-gradient(135deg, #10b981 0%, #059669 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

nav ul {
    list-style: none;
    display: flex;
    gap: 2.5rem;
    align-items: center;
    transition: max-height 0.3s ease;
    white-space: nowrap;
}

nav a {
    color: var(--text);
    text-decoration: none;
    font-weight: 500;
    font-size: 0.95rem;
    transition: all 0.3s;
}

nav a:hover {
    color: var(--secondary);
}

/* Highlighted nav link (Student Sponsorship) */
nav a.highlight {
    display: inline-flex;
    align-items: center;
    white-space: nowrap;
    padding: 0.35rem 0.9rem;
    border-radius: 999px;
    background: #fffbf0;
    color: #e67e22;
    font-weight: 600;
    box-shadow: 0 0 0 1px rgba(230, 126, 34, 0.18);
}

nav a.highlight:hover {
    background: #e67e22;
    color: #ffffff;
    box-shadow: 0 6px 14px rgba(230, 126, 34, 0.35);
    transform: translateY(-1px);
}

.hamburger {
    display: none;
}

/* Mobile Responsive Styles */
@media (max-width: 768px) {
    nav ul {
        position: fixed;
        top: 70px;
        left: 0;
        width: 100%;
        background: #ffffff;
        flex-direction: column;
        padding: 2rem 0;
        gap: 1.5rem;
        max-height: 0;
        overflow: hidden;
        box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
        border-bottom: 1px solid #e5f7eb;
    }

    nav ul.open {
        max-height: 300px;
    }

    .hamburger {
        display: block;
    }
}