.layout {
    display: grid;
    grid-template-areas:
        "header header header"
        "sidebar main toc"
        "footer footer footer";
    grid-template-columns: var(--sidebar-width) 1fr var(--toc-width);
    grid-template-rows: auto 1fr auto;
    min-height: 100vh;
}

header {
    grid-area: header;
    height: var(--header-height);
    background-color: var(--bg-primary);
    border-bottom: 1px solid var(--border-color);
    position: sticky;
    top: 0;
    z-index: 100;
    display: flex;
    align-items: center;
    padding: 0 2rem;
    justify-content: space-between;
    backdrop-filter: blur(8px);
    background-color: rgba(var(--bg-primary-rgb), 0.8);
}

.sidebar {
    grid-area: sidebar;
    background-color: var(--bg-secondary);
    border-right: 1px solid var(--border-color);
    position: sticky;
    top: var(--header-height);
    height: calc(100vh - var(--header-height));
    overflow-y: auto;
    padding: 2rem 1rem;
}

main {
    grid-area: main;
    padding: 2rem 4rem;
    max-width: 900px;
    margin: 0 auto;
    width: 100%;
}

.toc {
    grid-area: toc;
    padding: 2rem 1rem;
    position: sticky;
    top: var(--header-height);
    height: calc(100vh - var(--header-height));
    overflow-y: auto;
    font-size: 0.9rem;
}

/* Responsive adjustments */
@media (max-width: 1200px) {
    .layout {
        grid-template-areas:
            "header header"
            "sidebar main";
        grid-template-columns: var(--sidebar-width) 1fr;
    }

    .toc {
        display: none;
    }
}

@media (max-width: 768px) {
    .layout {
        grid-template-areas:
            "header"
            "main";
        grid-template-columns: 1fr;
    }

    .sidebar {
        display: none;
        /* Mobile menu will be handled by JS */
    }

    main {
        padding: 2rem 1.5rem;
    }
}

/* Animations */
@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(10px);
    }

    to {
        opacity: 1;
        transform: translateY(0);
    }
}

main {
    animation: fadeIn 0.5s ease-out forwards;
}

html {
    scroll-behavior: smooth;
}

/* Custom Scrollbar */
::-webkit-scrollbar {
    width: 6px;
    height: 6px;
}

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

::-webkit-scrollbar-thumb {
    background: var(--border-color);
    border-radius: 10px;
}

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