/* Layout System */
.container {
    width: 100%;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--space-4);
}

.section {
    padding: var(--space-16) 0;
}

.bg-alt {
    background-color: var(--color-bg-alt);
    border-top: 1px solid var(--glass-border);
    border-bottom: 1px solid var(--glass-border);
}

.section-header {
    margin-bottom: var(--space-12);
    text-align: center;
}

.section-title {
    font-size: clamp(2rem, 5vw, 2.5rem);
    margin-bottom: var(--space-4);
}

.section-subtitle {
    color: var(--color-text-muted);
    font-size: 1.125rem;
    max-width: 600px;
    margin: 0 auto;
}

.glass-panel {
    background: var(--color-surface);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border: 1px solid var(--glass-border);
    box-shadow: var(--glass-shadow);
    border-radius: var(--radius-lg);
}

/* Header */
.header {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    z-index: 1000;
    background-color: rgba(5, 10, 21, 0.8);
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
    border-bottom: 1px solid var(--glass-border);
    transition: transform var(--transition-normal), background-color var(--transition-normal);
}

.header.scrolled-down {
    transform: translateY(-100%);
}

.header.scrolled-up {
    transform: translateY(0);
    box-shadow: var(--glass-shadow);
}

body.theme-light .header {
    background-color: rgba(250, 250, 250, 0.8);
}

.scroll-progress {
    position: absolute;
    bottom: -1px;
    left: 0;
    width: 0%;
    height: 2px;
    background: var(--color-accent);
    transition: width 0.1s ease;
}

.nav {
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 70px;
}

.logo a {
    font-family: var(--font-display);
    font-weight: 700;
    font-size: 1.5rem;
    color: var(--color-text);
}

.nav-actions {
    display: flex;
    align-items: center;
    gap: var(--space-4);
}

/* Footer */
.footer {
    padding: var(--space-8) 0;
    text-align: center;
    color: var(--color-text-muted);
    border-top: 1px solid var(--glass-border);
    background-color: var(--color-bg);
}

/* Responsive */
@media (max-width: 768px) {
    .section {
        padding: var(--space-12) 0;
    }
    
    .nav-actions {
        gap: var(--space-2);
    }
    
    .nav-actions .btn {
        padding: 0.5rem 1rem;
        font-size: 0.875rem;
    }
}