:root {
    color-scheme: light dark;
    --font: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    --radius-xl: 28px;
    --radius-lg: 18px;
    --shadow: 0 24px 70px rgba(15, 23, 42, .12);
    --container: 1180px;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
    margin: 0;
    min-height: 100vh;
    font-family: var(--font);
    background: var(--bg);
    color: var(--text);
}
a { color: inherit; text-decoration: none; }
button, input { font: inherit; }
code {
    padding: .15rem .4rem;
    border-radius: 8px;
    background: var(--code-bg);
}
.app-shell {
    min-height: 100vh;
    display: grid;
    grid-template-columns: 290px 1fr;
    grid-template-rows: auto 1fr auto;
}
.topbar {
    grid-column: 1 / -1;
    position: sticky;
    top: 0;
    z-index: 20;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 1rem;
    padding: 18px clamp(18px, 4vw, 48px);
    background: color-mix(in srgb, var(--bg) 82%, transparent);
    backdrop-filter: blur(20px);
    border-bottom: 1px solid var(--border);
}
.brand { display: flex; align-items: center; gap: 14px; }
.brand-mark {
    display: grid;
    place-items: center;
    width: 48px;
    height: 48px;
    border-radius: 16px;
    color: white;
    font-weight: 900;
    font-size: 1.5rem;
    background: linear-gradient(135deg, var(--accent), var(--accent-2));
    box-shadow: var(--shadow);
}
.brand strong { display: block; font-size: 1.1rem; letter-spacing: -.02em; }
.brand small { color: var(--muted); }
.topbar-actions { display: flex; gap: 10px; }
.icon-button, .theme-toggle {
    border: 1px solid var(--border);
    background: var(--surface);
    color: var(--text);
    width: 44px;
    height: 44px;
    border-radius: 14px;
    cursor: pointer;
}
.sidebar {
    grid-row: 2 / 3;
    padding: 26px 18px 26px clamp(18px, 3vw, 34px);
    border-right: 1px solid var(--border);
}
.menu { display: grid; gap: 10px; }
.menu-link {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 14px 16px;
    border-radius: 16px;
    color: var(--muted);
    transition: .2s ease;
}
.menu-link:hover, .menu-link.active {
    color: var(--text);
    background: var(--surface);
    box-shadow: 0 12px 30px rgba(15, 23, 42, .08);
}
.sidebar-card {
    margin-top: 22px;
    padding: 18px;
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    background: var(--surface-soft);
    color: var(--muted);
}
.content {
    padding: clamp(22px, 4vw, 54px);
    max-width: var(--container);
    width: 100%;
}
.footer {
    grid-column: 1 / -1;
    display: flex;
    justify-content: space-between;
    gap: 1rem;
    padding: 20px clamp(18px, 4vw, 48px);
    border-top: 1px solid var(--border);
    color: var(--muted);
    font-size: .92rem;
}
@media (max-width: 900px) {
    .app-shell { grid-template-columns: 1fr; }
    .sidebar {
        display: none;
        border-right: 0;
        border-bottom: 1px solid var(--border);
        padding: 18px;
    }
    .sidebar.open { display: block; }
    .content { padding: 22px; }
    .footer { flex-direction: column; }
}