:root {
    --sidebar-width: 268px;
    --brand: #2563eb;
    --surface: #ffffff;
    --border: #e5e7eb;
    --muted: #6b7280;
    --body-bg: #f5f7fb;
}

body { background: var(--body-bg); }
.app-shell { min-height: 100vh; }
.app-sidebar {
    background: #111827;
    color: #fff;
    height: 100vh;
    left: 0;
    position: fixed;
    top: 0;
    width: var(--sidebar-width);
    z-index: 1030;
}
.sidebar-brand {
    align-items: center;
    border-bottom: 1px solid rgba(255,255,255,.1);
    display: flex;
    font-size: 1.15rem;
    font-weight: 700;
    gap: .75rem;
    padding: 1rem 1.25rem;
}
.brand-mark {
    align-items: center;
    background: var(--brand);
    border-radius: 8px;
    color: #fff;
    display: inline-flex;
    font-weight: 800;
    height: 38px;
    justify-content: center;
    width: 38px;
}
.sidebar-nav { padding: 1rem .75rem; }
.sidebar-nav a {
    align-items: center;
    border-radius: 8px;
    color: #d1d5db;
    display: flex;
    gap: .7rem;
    padding: .72rem .85rem;
    text-decoration: none;
}
.sidebar-nav a:hover { background: rgba(255,255,255,.08); color: #fff; }
.sidebar-heading {
    color: #9ca3af;
    font-size: .75rem;
    font-weight: 700;
    letter-spacing: .04em;
    padding: 1rem .85rem .35rem;
    text-transform: uppercase;
}
.app-main { margin-left: var(--sidebar-width); min-height: 100vh; }
.app-main.auth-main { margin-left: 0; }
.app-topbar { min-height: 64px; padding: .5rem 1.25rem; }
.app-content { padding: 1.5rem; }
.app-footer { color: var(--muted); font-size: .875rem; padding: 1rem 1.5rem 1.5rem; }
.page-heading { align-items: center; display: flex; justify-content: space-between; margin-bottom: 1rem; }
.page-heading h1 { font-size: 1.45rem; margin: 0 0 .25rem; }
.metric-card, .content-card {
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: 8px;
    box-shadow: 0 8px 24px rgba(15, 23, 42, .05);
}
.metric-card { padding: 1rem; }
.metric-card .metric-value { font-size: 1.8rem; font-weight: 800; }
.content-card { padding: 1rem; }
.auth-card { display: grid; min-height: calc(100vh - 64px); place-items: center; padding: 2rem; }
.auth-panel {
    background: #fff;
    border: 1px solid var(--border);
    border-radius: 8px;
    max-width: 430px;
    padding: 2rem;
    width: 100%;
}
.empty-state {
    background: #fff;
    border: 1px solid var(--border);
    border-radius: 8px;
    margin: 2rem auto;
    max-width: 620px;
    padding: 3rem;
    text-align: center;
}
.empty-state i { color: var(--brand); font-size: 3rem; }
.table-actions { display: flex; gap: .35rem; justify-content: flex-end; }
@media (max-width: 991.98px) {
    .app-sidebar { transform: translateX(-100%); transition: transform .2s ease; }
    .app-sidebar.show { transform: translateX(0); }
    .app-main { margin-left: 0; }
}