:root {
    --primary: #1d4ed8;
    --primary-dark: #1e3a8a;
    --bg: #f4f6fb;
    --sidebar-bg: #0f172a;
    --sidebar-text: #cbd5e1;
    --sidebar-active: #1d4ed8;
    --card-bg: #ffffff;
    --border: #e2e8f0;
    --text: #1e293b;
    --text-muted: #64748b;
    --success: #16a34a;
    --warning: #d97706;
    --danger: #dc2626;
    --radius: 8px;
}

* { box-sizing: border-box; }

body {
    margin: 0;
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Arial, sans-serif;
    background: var(--bg);
    color: var(--text);
    font-size: 14px;
}

a { color: var(--primary); text-decoration: none; }

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

.sidebar {
    width: 240px;
    background: var(--sidebar-bg);
    color: var(--sidebar-text);
    display: flex;
    flex-direction: column;
    flex-shrink: 0;
}

.sidebar-brand {
    padding: 20px 16px;
    border-bottom: 1px solid rgba(255,255,255,0.08);
}
.brand-name { display: block; font-weight: 700; font-size: 16px; color: #fff; }
.brand-version { display: block; font-size: 11px; color: #94a3b8; margin-top: 2px; }

.sidebar-nav { flex: 1; padding: 12px 0; display: flex; flex-direction: column; }
.sidebar-nav a {
    color: var(--sidebar-text);
    padding: 11px 20px;
    font-size: 14px;
    border-left: 3px solid transparent;
}
.sidebar-nav a:hover { background: rgba(255,255,255,0.06); color: #fff; }
.sidebar-nav a.active {
    background: rgba(29,78,216,0.25);
    border-left-color: var(--sidebar-active);
    color: #fff;
    font-weight: 600;
}

.sidebar-footer { padding: 14px 20px; border-top: 1px solid rgba(255,255,255,0.08); font-size: 12px; color: #94a3b8; }

.main-area { flex: 1; display: flex; flex-direction: column; min-width: 0; }

.topbar {
    height: 60px;
    background: var(--card-bg);
    border-bottom: 1px solid var(--border);
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 0 24px;
}
.page-title { font-size: 18px; margin: 0; }
.topbar-actions { display: flex; align-items: center; gap: 16px; }
.current-user { color: var(--text-muted); }
.btn-change-password { color: var(--primary); font-weight: 600; }
.btn-logout { color: var(--danger); font-weight: 600; }

.bell-icon { position: relative; font-size: 18px; cursor: pointer; }
.bell-badge {
    position: absolute; top: -6px; right: -8px;
    background: var(--danger); color: #fff;
    font-size: 10px; font-weight: 700;
    border-radius: 999px; padding: 1px 5px; min-width: 16px; text-align: center;
}

.content, .content-plain { padding: 24px; flex: 1; }
.content-plain { display: flex; align-items: center; justify-content: center; min-height: 100vh; padding: 0; }

/* ---------- Alerts / flash messages ---------- */
.alert { padding: 10px 16px; border-radius: var(--radius); margin-bottom: 16px; font-size: 13px; }
.alert-success { background: #dcfce7; color: #166534; border: 1px solid #bbf7d0; }
.alert-error { background: #fee2e2; color: #991b1b; border: 1px solid #fecaca; }
.alert-info { background: #dbeafe; color: #1e40af; border: 1px solid #bfdbfe; }
.alert-warning { background: #fef3c7; color: #92400e; border: 1px solid #fde68a; }

/* ---------- Cards ---------- */
.card {
    background: var(--card-bg);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 20px;
    margin-bottom: 20px;
}

.summary-cards { display: grid; grid-template-columns: repeat(4, 1fr); gap: 16px; margin-bottom: 20px; }
.summary-card { background: var(--card-bg); border: 1px solid var(--border); border-radius: var(--radius); padding: 18px; }
.summary-card .label { font-size: 12px; color: var(--text-muted); text-transform: uppercase; letter-spacing: 0.04em; }
.summary-card .value { font-size: 26px; font-weight: 700; margin-top: 6px; }
.summary-card.critical .value { color: var(--danger); }

/* ---------- Forms ---------- */
.form-group { margin-bottom: 14px; }
label { display: block; font-weight: 600; margin-bottom: 5px; font-size: 13px; }
input[type=text], input[type=password], input[type=number], input[type=date], input[type=email], select, textarea {
    width: 100%;
    padding: 9px 11px;
    border: 1px solid var(--border);
    border-radius: 6px;
    font-size: 14px;
    background: #fff;
    color: var(--text);
}
input:disabled, select:disabled { background: #f1f5f9; color: var(--text-muted); }
.form-hint { font-size: 12px; color: var(--text-muted); margin-top: 4px; }
.form-error { font-size: 12px; color: var(--danger); margin-top: 4px; }
.form-row { display: flex; gap: 16px; }
.form-row > .form-group { flex: 1; }

.btn {
    display: inline-block;
    padding: 9px 18px;
    border-radius: 6px;
    border: none;
    background: var(--primary);
    color: #fff;
    font-weight: 600;
    font-size: 14px;
    cursor: pointer;
}
.btn:hover { background: var(--primary-dark); }
.btn-secondary { background: #e2e8f0; color: var(--text); }
.btn-secondary:hover { background: #cbd5e1; }
.btn-danger { background: var(--danger); }
.btn-sm { padding: 5px 10px; font-size: 12px; }

/* ---------- Tables ---------- */
table { width: 100%; border-collapse: collapse; background: var(--card-bg); }
thead th {
    text-align: left;
    font-size: 12px;
    text-transform: uppercase;
    letter-spacing: 0.03em;
    color: var(--text-muted);
    border-bottom: 2px solid var(--border);
    padding: 10px 12px;
}
tbody td { padding: 10px 12px; border-bottom: 1px solid var(--border); }
tbody tr:hover { background: #f8fafc; }
tbody tr.row-critical { background: #fef2f2; }
tbody tr.row-critical:hover { background: #fee2e2; }

.badge { display: inline-block; padding: 2px 9px; border-radius: 999px; font-size: 11px; font-weight: 700; }
.badge-critical { background: #fee2e2; color: var(--danger); }
.badge-low { background: #fef3c7; color: var(--warning); }
.badge-ok { background: #dcfce7; color: var(--success); }
.badge-inactive { background: #e2e8f0; color: var(--text-muted); }

.filters { display: flex; gap: 12px; align-items: end; margin-bottom: 16px; flex-wrap: wrap; }
.filters .form-group { margin-bottom: 0; min-width: 160px; }

.toolbar { display: flex; justify-content: space-between; align-items: center; margin-bottom: 16px; }

/* ---------- Login page ---------- */
.login-box {
    width: 380px;
    background: var(--card-bg);
    border-radius: 12px;
    padding: 36px;
    box-shadow: 0 10px 40px rgba(15,23,42,0.12);
}
.login-box h1 { font-size: 20px; margin: 0 0 4px; }
.login-box .subtitle { color: var(--text-muted); font-size: 13px; margin-bottom: 24px; }
.login-box .btn { width: 100%; padding: 11px; margin-top: 6px; }
.login-footer { text-align: center; margin-top: 18px; font-size: 12px; color: var(--text-muted); }

/* ---------- Notification dropdown ---------- */
.notif-dropdown {
    position: absolute; top: 52px; right: 24px;
    width: 340px; max-height: 420px; overflow-y: auto;
    background: #fff; border: 1px solid var(--border); border-radius: var(--radius);
    box-shadow: 0 12px 32px rgba(15,23,42,0.15);
    display: none; z-index: 50;
}
.notif-dropdown.open { display: block; }
.notif-item { padding: 12px 16px; border-bottom: 1px solid var(--border); font-size: 13px; }
.notif-item .notif-title { font-weight: 600; }
.notif-item .notif-meta { color: var(--text-muted); font-size: 12px; margin-top: 2px; }

@media (max-width: 1366px) {
    .summary-cards { grid-template-columns: repeat(2, 1fr); }
}