:root {
    --primary: #3b82f6;
    --primary-dark: #1d4ed8;
    --secondary: #64748b;
    --dark-bg: #0f172a;
    --dark-card: #1e293b;
    --light-text: #f8fafc;
    --gray-text: #94a3b8;
    --accent: #06b6d4;
    --gradient-main: linear-gradient(135deg, #3b82f6 0%, #06b6d4 100%);
    --glass: rgba(30, 41, 59, 0.7);
    --border: rgba(255, 255, 255, 0.1);
}

body {
    font-family: system-ui, -apple-system, sans-serif;
    background-color: var(--dark-bg);
    /* Premium Space Background - responsive (mobile-friendly) */
    background-image: linear-gradient(to bottom, rgba(15, 23, 42, 0.2), rgba(15, 23, 42, 0.6)), url('../img/hero-bg-800.jpg');
    background-image: linear-gradient(to bottom, rgba(15, 23, 42, 0.2), rgba(15, 23, 42, 0.6)), -webkit-image-set(
        url('../img/hero-bg-800.jpg') 1x,
        url('../img/hero-bg-1600.jpg') 2x
    );
    background-image: linear-gradient(to bottom, rgba(15, 23, 42, 0.2), rgba(15, 23, 42, 0.6)), image-set(
        url('../img/hero-bg-800.jpg') 1x,
        url('../img/hero-bg-1600.jpg') 2x
    );
    background-size: cover;
    background-position: center;
    background-attachment: fixed;
    color: var(--light-text);
    line-height: 1.8;
    overflow-x: hidden;
}

@media (max-width: 768px) {
    body {
        background-attachment: scroll;
    }
}

/* Typography */
h1, h2, h3, h4, h5, h6 {
    font-weight: 700;
    letter-spacing: -0.02em;
    color: #fff;
}

.text-gradient {
    background: var(--gradient-main);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

/* Navigation */
.nav-glass {
    background: var(--glass);
    backdrop-filter: blur(12px);
    border-bottom: 1px solid var(--border);
    transition: all 0.3s ease;
}

.nav-link {
    color: var(--gray-text);
    font-weight: 500;
    transition: color 0.3s;
    position: relative;
}

.nav-link:hover, .nav-link.active {
    color: #fff;
}

.nav-link::after {
    content: '';
    position: absolute;
    width: 0;
    height: 2px;
    bottom: -4px;
    left: 0;
    background: var(--gradient-main);
    transition: width 0.3s;
}

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

/* Buttons */
.btn-primary {
    background: var(--gradient-main);
    color: white;
    padding: 12px 32px;
    border-radius: 50px;
    font-weight: 600;
    transition: transform 0.3s, box-shadow 0.3s;
    box-shadow: 0 4px 20px rgba(59, 130, 246, 0.3);
    display: inline-block;
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 30px rgba(59, 130, 246, 0.5);
}

.btn-outline {
    background: transparent;
    border: 2px solid var(--primary);
    color: white;
    padding: 12px 32px;
    border-radius: 50px;
    font-weight: 600;
    transition: all 0.3s;
    display: inline-block;
}

.btn-outline:hover {
    background: rgba(59, 130, 246, 0.1);
    transform: translateY(-2px);
}

/* Cards & Sections */
.card-premium {
    background: var(--dark-card);
    border: 1px solid var(--border);
    border-radius: 24px;
    padding: 40px;
    transition: transform 0.3s, border-color 0.3s;
    height: 100%;
}

.card-premium:hover {
    transform: translateY(-5px);
    border-color: var(--primary);
}

.section-title {
    font-size: 3rem;
    margin-bottom: 1.5rem;
    line-height: 1.2;
}

.feature-icon {
    width: 64px;
    height: 64px;
    background: rgba(59, 130, 246, 0.1);
    border-radius: 16px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 24px;
    color: var(--primary);
    margin-bottom: 24px;
}

/* Hero Background */
.hero-bg {
    /* Background handled by body for consistency */
    position: relative;
}

/* Animations */
.reveal {
    opacity: 0;
    transform: translate3d(0, 20px, 0);
    transition: opacity 0.55s cubic-bezier(0.5, 0, 0, 1), transform 0.55s cubic-bezier(0.5, 0, 0, 1);
    will-change: opacity, transform;
}

.reveal.active {
    opacity: 1;
    transform: translate3d(0, 0, 0);
}

@media (prefers-reduced-motion: reduce) {
    .reveal {
        opacity: 1;
        transform: none;
        transition: none;
        will-change: auto;
    }
}

/* Stats Counter */
.stat-number {
    font-size: 3.5rem;
    font-weight: 800;
    background: var(--gradient-main);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

/* Custom Scrollbar */
::-webkit-scrollbar {
    width: 10px;
}

::-webkit-scrollbar-track {
    background: var(--dark-bg);
}

::-webkit-scrollbar-thumb {
    background: var(--dark-card);
    border-radius: 5px;
}

::-webkit-scrollbar-thumb:hover {
    background: var(--secondary);
}

/* Logo */
.logo-svg {
    fill: url(#logo-gradient);
}