html, body {
    font-family: Inter, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
    background: #f4f7fb;
    color: #1f2937;
    margin: 0;
}

.shell {
    display: grid;
    grid-template-columns: 260px 1fr;
    min-height: 100vh;
}

.sidebar {
    background: #0f172a;
    color: white;
    padding: 24px 18px;
    display: flex;
    flex-direction: column;
    gap: 18px;
}

.sidebar .brand {
    font-size: 1.2rem;
    font-weight: 700;
}

.sidebar .nav a {
    color: rgba(255, 255, 255, 0.86);
    text-decoration: none;
    padding: 10px 12px;
    border-radius: 10px;
    margin-bottom: 6px;
    display: block;
}

.sidebar .nav a.active,
.sidebar .nav a:hover {
    background: rgba(255,255,255,0.12);
    color: white;
}

.logout-form {
    margin-top: auto;
}

.content {
    padding: 28px;
}

.stats-grid {
    display: grid;
    grid-template-columns: repeat(4, minmax(160px, 1fr));
    gap: 16px;
}

.stat-card {
    background: white;
    border-radius: 16px;
    padding: 18px;
    box-shadow: 0 8px 24px rgba(15, 23, 42, 0.06);
}

.stat-card .label {
    color: #64748b;
    font-size: 0.9rem;
    margin-bottom: 8px;
}

.stat-card .value {
    font-size: 2rem;
    font-weight: 700;
}

.card {
    border: 0;
    border-radius: 16px;
    box-shadow: 0 8px 24px rgba(15, 23, 42, 0.06);
}

.login-body {
    min-height: 100vh;
    display: grid;
    place-items: center;
    background: linear-gradient(135deg, #eff6ff, #f8fafc);
}

.login-card {
    width: min(420px, calc(100vw - 32px));
    background: white;
    border-radius: 18px;
    padding: 28px;
    box-shadow: 0 18px 50px rgba(15, 23, 42, 0.12);
}

.form-label {
    display: block;
    margin-bottom: 6px;
    font-weight: 600;
}

.form-control,
.form-select {
    width: 100%;
    border: 1px solid #cbd5e1;
    border-radius: 10px;
    padding: 10px 12px;
    box-sizing: border-box;
    background: white;
}

.btn {
    border: 0;
    padding: 10px 14px;
    border-radius: 10px;
    cursor: pointer;
}

.btn-primary {
    background: #2563eb;
    color: white;
}

.btn-secondary {
    background: #64748b;
    color: white;
}

.btn-outline-light {
    background: transparent;
    color: white;
    border: 1px solid rgba(255,255,255,0.35);
}

.table {
    width: 100%;
    border-collapse: collapse;
}

.table th,
.table td {
    text-align: left;
    padding: 10px 8px;
    border-bottom: 1px solid #e2e8f0;
}

.list-group-item {
    width: 100%;
    text-align: left;
    background: white;
    border: 1px solid #e2e8f0;
    padding: 10px 12px;
    margin-bottom: 6px;
    border-radius: 10px;
    cursor: pointer;
}

.list-group-item.active {
    background: #dbeafe;
    border-color: #93c5fd;
}

.row {
    display: flex;
    gap: 16px;
    flex-wrap: wrap;
}

.col-2 { flex: 0 0 calc(16.666% - 16px); min-width: 120px; }
.col-3 { flex: 0 0 calc(25% - 16px); min-width: 180px; }
.col-4 { flex: 0 0 calc(33.333% - 16px); min-width: 220px; }
.col-6 { flex: 0 0 calc(50% - 16px); min-width: 240px; }
.col-8 { flex: 0 0 calc(66.666% - 16px); min-width: 280px; }
.col-9 { flex: 0 0 calc(75% - 16px); min-width: 320px; }

.mt-4 { margin-top: 1.5rem; }
.mb-3 { margin-bottom: 1rem; }
.mb-4 { margin-bottom: 1.5rem; }
.me-2 { margin-right: 0.5rem; }
.p-3 { padding: 1rem; }
.text-muted { color: #64748b; }
.alert {
    padding: 12px 14px;
    border-radius: 10px;
    margin-bottom: 16px;
}
.alert-info { background: #eff6ff; color: #1d4ed8; }
.alert-danger { background: #fef2f2; color: #b91c1c; }

@media (max-width: 900px) {
    .shell {
        grid-template-columns: 1fr;
    }

    .sidebar {
        min-height: auto;
    }

    .stats-grid {
        grid-template-columns: 1fr 1fr;
    }
}