:root {
    --sidebar-width: 250px;
    --brand-color: #1e3a5f;
    --brand-color-light: #2c527f;
}

body {
    background: #f4f6f9;
}

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

.sidebar {
    width: var(--sidebar-width);
    background: var(--brand-color);
    color: #fff;
    flex-shrink: 0;
    position: fixed;
    top: 0;
    bottom: 0;
    left: 0;
    overflow-y: auto;
    z-index: 1030;
    transition: transform 0.2s ease;
}

.sidebar-brand {
    padding: 1.1rem 1rem;
    font-weight: 600;
    font-size: 1.1rem;
    display: flex;
    align-items: center;
    gap: .5rem;
    border-bottom: 1px solid rgba(255,255,255,.1);
}

.sidebar .nav-heading {
    text-transform: uppercase;
    font-size: .7rem;
    letter-spacing: .05em;
    opacity: .6;
    padding: 1rem 1rem .25rem;
}

.sidebar .nav-link {
    color: rgba(255,255,255,.85);
    padding: .5rem 1rem;
    border-radius: 0;
}

.sidebar .nav-link i { width: 1.3rem; text-align: center; margin-right: .4rem; }

.sidebar .nav-link:hover,
.sidebar .nav-link.active {
    background: var(--brand-color-light);
    color: #fff;
}

.main-area {
    margin-left: var(--sidebar-width);
    flex-grow: 1;
    display: flex;
    flex-direction: column;
    min-width: 0;
}

.topbar {
    background: #fff;
    border-bottom: 1px solid #e5e7eb;
    padding: .75rem 1.25rem;
    display: flex;
    align-items: center;
    gap: 1rem;
    position: sticky;
    top: 0;
    z-index: 1020;
}

.topbar .page-title {
    font-size: 1.15rem;
    font-weight: 600;
    margin: 0;
    flex-grow: 1;
}

.topbar-right {
    display: flex;
    align-items: center;
    gap: .75rem;
}

.content {
    padding: 1.5rem;
}

.summary-card {
    border: none;
    border-radius: .6rem;
    box-shadow: 0 1px 3px rgba(0,0,0,.08);
}

.login-split {
    min-height: 100vh;
    display: flex;
}

.login-brand-panel {
    background: linear-gradient(135deg, var(--brand-color), var(--brand-color-light));
    color: #fff;
    flex: 1;
    display: flex;
    flex-direction: column;
    justify-content: center;
    padding: 3rem;
}

.login-form-panel {
    flex: 1;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 2rem;
    background: #fff;
}

@media (max-width: 991px) {
    .login-brand-panel { display: none; }
    .sidebar { transform: translateX(-100%); }
    .sidebar.show { transform: translateX(0); }
    .main-area { margin-left: 0; }
}