:root {
    --bg-dark: #010103;
    --bg-card: rgba(10, 14, 22, 0.45);
    --glass-border: rgba(255, 255, 255, 0.06);
    --accent: #8b5cf6;
    --accent-glow: rgba(139, 92, 246, 0.3);
    --text-primary: #ffffff;
    --text-secondary: #94a3b8;
    --nav-bg: rgba(5, 5, 8, 0.6);
}

[data-lang="ru"] .en,
[data-lang="ru"] .lang-en { display: none !important; }

[data-lang="en"] .ru,
[data-lang="en"] .lang-ru { display: none !important; }

body {
    font-family: 'Inter', -apple-system, sans-serif;
    margin: 0;
    background-color: var(--bg-dark);
    background-image: 
        radial-gradient(circle at 15% 0%, rgba(139, 92, 246, 0.12) 0%, transparent 40%),
        radial-gradient(circle at 85% 100%, rgba(29, 78, 216, 0.08) 0%, transparent 40%);
    background-attachment: fixed;
    color: var(--text-primary);
    line-height: 1.6;
    -webkit-font-smoothing: antialiased;
}

.header-wrapper {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 16px 5%;
    box-sizing: border-box;
    background: rgba(2, 2, 4, 0.7);
    backdrop-filter: blur(24px);
    -webkit-backdrop-filter: blur(24px);
    border-bottom: 1px solid var(--glass-border);
    z-index: 1000;
}

.header-logo {
    font-weight: 800;
    font-size: 1.2rem;
    letter-spacing: -0.5px;
    background: linear-gradient(135deg, #fff 0%, #a78bfa 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    text-decoration: none;
}

.glass-nav {
    display: flex;
    align-items: center;
    gap: 8px;
    background: rgba(255, 255, 255, 0.03);
    padding: 6px;
    border-radius: 100px;
    border: 1px solid var(--glass-border);
}

.nav-item {
    text-decoration: none;
    color: var(--text-secondary);
    padding: 8px 20px;
    border-radius: 100px;
    font-size: 14px;
    font-weight: 600;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

.nav-item:hover {
    color: var(--text-primary);
    background: rgba(255, 255, 255, 0.05);
}

.nav-item.active {
    background: var(--accent);
    color: white;
    box-shadow: 0 4px 20px var(--accent-glow);
}

.header-actions {
    display: flex;
    align-items: center;
}

.icon-btn {
    background: rgba(255, 255, 255, 0.05);
    border: 1px solid var(--glass-border);
    color: var(--text-primary);
    cursor: pointer;
    font-weight: 700;
    padding: 8px 16px;
    border-radius: 12px;
    font-size: 13px;
    transition: 0.2s;
}

.icon-btn:hover {
    background: rgba(255, 255, 255, 0.1);
}

.container {
    max-width: 900px;
    margin: 120px auto 80px;
    padding: 0 24px;
}

.main-box {
    background: var(--bg-card);
    backdrop-filter: blur(40px);
    -webkit-backdrop-filter: blur(40px);
    border-radius: 32px;
    border: 1px solid var(--glass-border);
    padding: 48px;
    box-shadow: 0 30px 60px -15px rgba(0, 0, 0, 0.6);
}

@media (max-width: 768px) {
    .header-wrapper {
        flex-direction: column;
        padding: 12px;
        gap: 16px;
    }
    .header-logo { display: none; }
    .header-actions { position: absolute; right: 20px; top: 20px; }
    .main-box { padding: 32px 20px; }
}