body {
    font-family: "Segoe UI", system-ui, sans-serif;
    background: #eef2ff;
    margin: 0;
}

.app-shell {
    display: flex;
    min-height: 100vh;
}

.sidebar {
    width: 240px;
    background: #2f353d;
    color: #e7ebef;
    display: flex;
    flex-direction: column;
    padding: 1.5rem 1.25rem;
    gap: 1.5rem;
}

.sidebar-header {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    padding-bottom: 1rem;
    border-bottom: 1px solid rgba(255, 255, 255, 0.08);
}

.sidebar-avatar {
    width: 44px;
    height: 44px;
    border-radius: 50%;
    background: #1f6feb;
    display: grid;
    place-items: center;
    font-weight: 700;
}

.sidebar-name {
    font-weight: 700;
}

.sidebar-role {
    font-size: 0.75rem;
    color: #b7c0c9;
}

.sidebar-section {
    font-size: 0.75rem;
    text-transform: uppercase;
    letter-spacing: 0.08em;
    color: #8d97a1;
}

.sidebar-nav {
    display: flex;
    flex-direction: column;
    gap: 0.35rem;
}

.sidebar-link {
    display: flex;
    align-items: center;
    gap: 0.6rem;
    padding: 0.5rem 0.75rem;
    border-radius: 8px;
    color: inherit;
    text-decoration: none;
    font-weight: 600;
}

.sidebar-link:hover,
.sidebar-link.active {
    background: #1971f3;
    color: #fff;
}

.sidebar-link svg {
    width: 18px;
    height: 18px;
    flex-shrink: 0;
}

.sidebar-footer {
    margin-top: auto;
}

.app-content {
    flex: 1;
    display: flex;
    flex-direction: column;
}

header {
    padding: 1rem 2rem;
    background: #0d6efd;
    color: #fff;
}

main {
    padding: 2rem;
    max-width: 1200px;
    width: 100%;
    margin: 0 auto;
}

.flash {
    background: #d1e7dd;
    color: #0f5132;
    border-radius: 4px;
    padding: 0.75rem 1rem;
    margin-bottom: 1rem;
}

.tab-button {
    display: none;
}

.tab-content {
    display: none;
}

.tab-content.active {
    display: block;
}

@media (max-width: 920px) {
    .app-shell {
        flex-direction: column;
    }

    .sidebar {
        width: 100%;
        flex-direction: row;
        flex-wrap: wrap;
        gap: 1rem;
    }

    .sidebar-header {
        border-bottom: none;
        padding-bottom: 0;
    }

    .sidebar-footer {
        width: 100%;
    }
}