:root {
    --pure-water-blue: #E0F2F1;
    --deep-sea-blue: #0077B6;
    --recycle-green: #4CAF50;
    --ion-purple: #673AB7;
    --stainless-steel: #B0BEC5;
    --dark-bg: #0A192F;
    --text-main: #263238;
    --text-light: #546E7A;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
    color: var(--text-main);
    background-color: #ffffff;
    line-height: 1.6;
    overflow-x: hidden;
}

.mono-font {
    font-family: 'JetBrains Mono', 'Courier New', monospace;
}

/* Navbar Styling */
.navbar {
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid var(--pure-water-blue);
    padding: 1rem 0;
}

.navbar-brand {
    font-weight: 800;
    color: var(--deep-sea-blue) !important;
    letter-spacing: -0.5px;
}

.nav-link {
    font-weight: 500;
    color: var(--text-main) !important;
    margin: 0 10px;
    transition: color 0.3s ease;
}

.nav-link:hover, .nav-link.active {
    color: var(--deep-sea-blue) !important;
}

/* Hero Section */
.hero-section {
    background: linear-gradient(135deg, var(--pure-water-blue) 0%, #ffffff 100%);
    padding: 120px 0 80px;
    position: relative;
    overflow: hidden;
}

.hero-visual {
    position: relative;
    min-height: 400px;
    display: flex;
    align-items: center;
    justify-content: center;
}

/* Membrane Animation Placeholder */
.membrane-module {
    width: 300px;
    height: 150px;
    border: 3px solid var(--stainless-steel);
    border-radius: 75px;
    position: relative;
    background: rgba(255,255,255,0.5);
    box-shadow: 0 0 30px rgba(0,119,182,0.1);
}

/* Footer */
footer {
    background: var(--dark-bg);
    color: white;
    padding: 60px 0 30px;
}

.footer-logo {
    font-size: 1.5rem;
    font-weight: 700;
    margin-bottom: 20px;
    display: block;
}

/* Utility Classes */
.text-pure-blue { color: var(--pure-water-blue); }
.text-deep-blue { color: var(--deep-sea-blue); }
.text-recycle-green { color: var(--recycle-green); }
.text-ion-purple { color: var(--ion-purple); }

.bg-pure-blue { background-color: var(--pure-water-blue); }
.bg-deep-blue { background-color: var(--deep-sea-blue); }

.section-title {
    font-weight: 700;
    margin-bottom: 40px;
    position: relative;
    padding-bottom: 15px;
}

.section-title::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 60px;
    height: 4px;
    background: var(--deep-sea-blue);
}

.card {
    border: 1px solid var(--pure-water-blue);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.card:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 30px rgba(0,119,182,0.1);
}