:root {
    --primary: #4361ee;
    --secondary: #3a0ca3;
    --accent: #f72585;
    --light: #f8f9fa;
    --dark: #212529;
    --gradient-1: #4361ee;
    --gradient-2: #3a0ca3;
    --gradient-3: #7209b7;
    --gradient-4: #f72585;
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'Poppins', sans-serif;
    background-color: var(--light);
    color: var(--dark);
    overflow-x: hidden;
    position: relative;
    padding-top: 60px;
}

.color-gradient-bg {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100vh;
    background: linear-gradient(135deg, var(--gradient-1), var(--gradient-2), var(--gradient-3), var(--gradient-4));
    background-size: 400% 400%;
    animation: gradientShift 15s ease infinite;
    z-index: -2;
    opacity: 0.1;
}

@keyframes gradientShift {
    0% { background-position: 0% 50%; }
    50% { background-position: 100% 50%; }
    100% { background-position: 0% 50%; }
}

.glass-nav {
    background: rgba(255, 255, 255, 0.85);
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
    box-shadow: 0 4px 30px rgba(0, 0, 0, 0.1);
    padding: 0.5rem 2%;
    display: flex;
    justify-content: space-between;
    align-items: center;
    position: fixed;
    width: 100%;
    top: 0;
    z-index: 1000;
    border-bottom: 1px solid rgba(255, 255, 255, 0.3);
    height: 60px;
    gap: 1rem;
}

.logo-container {
    display: flex;
    align-items: center;
    gap: 0.6rem;
    flex-shrink: 0;
    min-width: auto;
}

.logo-icon {
    width: 1.75rem;
    height: 1.75rem;
    fill: var(--primary);
}

.logo-text {
    font-family: 'Playfair Display', serif;
    font-weight: 700;
    font-size: 1.25rem;
    background: linear-gradient(to right, var(--primary), var(--secondary));
    -webkit-background-clip: text;
    background-clip: text;
    color: transparent;
    white-space: nowrap;
}

.logo-text span {
    font-weight: 400;
    color: var(--dark);
}

.nav-container {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    flex: 1;
    justify-content: flex-end;
}

.main-nav ul {
    display: flex;
    list-style: none;
    gap: 1.2rem;
    margin: 0;
    padding: 0;
    align-items: center;
}

.nav-link {
    text-decoration: none;
    color: var(--dark);
    font-weight: 500;
    position: relative;
    padding: 0.3rem 0;
    transition: color 0.3s ease;
    font-size: 0.95rem;
    white-space: nowrap;
}

.nav-link::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--accent);
    transition: width 0.3s ease;
}

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

.nav-link:hover::after {
    width: 100%;
}

.nav-link.active {
    color: var(--primary);
    font-weight: 600;
}

.nav-link.active::after {
    width: 100%;
}

.mobile-menu-toggle {
    display: none;
    background: none;
    border: none;
    cursor: pointer;
    padding: 0.5rem;
    z-index: 1001;
}

.mobile-menu-toggle span {
    display: block;
    width: 25px;
    height: 3px;
    background: var(--primary);
    margin: 4px 0;
    transition: all 0.3s ease;
}

main {
    margin-top: 10px;
    min-height: calc(100vh - 70px);
    padding: 1rem 5%;
}

@media (max-width: 1400px) {
    .nav-link {
        font-size: 0.9rem;
    }
    .main-nav ul {
        gap: 1rem;
    }
    .logo-text {
        font-size: 1.1rem;
    }
}

@media (max-width: 1200px) {
    .nav-link {
        font-size: 0.85rem;
    }
    .main-nav ul {
        gap: 0.8rem;
    }
}

@media (max-width: 1024px) {
    .main-nav {
        display: none;
    }
    
    .main-nav.active {
        display: flex;
        position: fixed;
        top: 60px;
        left: 0;
        width: 100%;
        height: calc(100vh - 60px);
        background: rgba(255, 255, 255, 0.95);
        backdrop-filter: blur(10px);
        -webkit-backdrop-filter: blur(10px);
        flex-direction: column;
        justify-content: flex-start;
        align-items: center;
        z-index: 999;
        padding-top: 2rem;
    }

    .main-nav.active ul {
        flex-direction: column;
        align-items: center;
        gap: 1.5rem;
        margin: 0;
    }

    .mobile-menu-toggle {
        display: block;
    }
    
    body {
        padding-top: 60px;
    }
}

@media (max-width: 768px) {
    .glass-nav {
        padding: 0.5rem 2%;
    }
    
    .logo-text {
        font-size: 1.1rem;
    }
}

.mobile-menu-toggle.active span:nth-child(1) {
    transform: rotate(45deg) translate(5px, 5px);
}

.mobile-menu-toggle.active span:nth-child(2) {
    opacity: 0;
}

.mobile-menu-toggle.active span:nth-child(3) {
    transform: rotate(-45deg) translate(7px, -6px);
}

/* AI Hub specific header styles */
body.ai-hub-page .glass-nav {
    background: #1a202c; /* A dark background color */
    border-bottom: 1px solid #4a5568; /* A subtle border */
}

body.ai-hub-page .nav-link {
    color: #ffffff; /* White text for visibility */
}

body.ai-hub-page .nav-link:hover,
body.ai-hub-page .nav-link.active {
    color: #8a4dff; /* A bright purple for hover/active state */
}

body.ai-hub-page .nav-link.active::after {
    background-color: #8a4dff;
}

body.ai-hub-page .mobile-menu-toggle span {
    background: #ffffff; /* White hamburger icon */
}

body.ai-hub-page .logo-text {
    background: none;
    -webkit-background-clip: initial;
    background-clip: initial;
    color: #ffffff;
}

body.ai-hub-page .logo-text span {
    color: #ffffff;
}