/* Dark NOC — Autonomous Operations Dashboard
   Airtel Brand: Red (#ED1C24), White, Black
   ============================================ */

:root {
    --dn-red: #ED1C24;
    --dn-red-dark: #C41920;
    --dn-red-light: #FF4D54;
    --dn-black: #0A0A0A;
    --dn-bg: #F8F9FA;
    --dn-card: #FFFFFF;
    --dn-text: #1A1A1A;
    --dn-text-secondary: #4A4A4A;
    --dn-text-muted: #6B7280;
    --dn-border: #E5E7EB;
    --dn-success: #10B981;
    --dn-success-bg: #ECFDF5;
    --dn-warning: #F59E0B;
    --dn-warning-bg: #FFFBEB;
    --dn-danger: #EF4444;
    --dn-danger-bg: #FEF2F2;
    --dn-info: #3B82F6;
    --dn-info-bg: #EFF6FF;
    --dn-shadow: 0 1px 3px rgba(0,0,0,0.08);
    --dn-shadow-md: 0 4px 12px rgba(0,0,0,0.1);
    --dn-radius: 10px;
    --dn-radius-sm: 6px;
}

* { margin: 0; padding: 0; box-sizing: border-box; }

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    background: var(--dn-bg);
    color: var(--dn-text);
    display: flex;
    min-height: 100vh;
}

/* ============================================
   Sidebar
   ============================================ */
.dn-sidebar {
    width: 240px;
    background: var(--dn-black);
    color: #fff;
    display: flex;
    flex-direction: column;
    position: fixed;
    top: 0;
    left: 0;
    bottom: 0;
    z-index: 100;
}

.dn-logo {
    padding: 20px 16px 16px;
    border-bottom: 1px solid rgba(255,255,255,0.08);
}

.dn-logo-title {
    font-size: 18px;
    font-weight: 700;
    letter-spacing: 0.5px;
}

.dn-logo-title span { color: var(--dn-red); }

.dn-logo-sub {
    font-size: 10px;
    color: rgba(255,255,255,0.4);
    text-transform: uppercase;
    letter-spacing: 1px;
    margin-top: 2px;
}

.dn-nav {
    flex: 1;
    padding: 12px 8px;
    overflow-y: auto;
}

.dn-nav-item {
    display: flex;
    align-items: center;
    gap: 10px;
    padding: 10px 12px;
    border-radius: var(--dn-radius-sm);
    color: rgba(255,255,255,0.6);
    text-decoration: none;
    font-size: 13px;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.2s;
    margin-bottom: 2px;
}

.dn-nav-item:hover {
    background: rgba(255,255,255,0.06);
    color: #fff;
}

.dn-nav-item.active {
    background: rgba(237,28,36,0.15);
    color: #fff;
}

.dn-nav-item.active .dn-nav-icon { color: var(--dn-red); }

.dn-nav-icon {
    width: 18px;
    height: 18px;
    flex-shrink: 0;
}

.dn-sidebar-footer {
    padding: 12px 16px;
    border-top: 1px solid rgba(255,255,255,0.08);
    display: flex;
    align-items: center;
    gap: 8px;
}

.dn-sidebar-footer a {
    font-size: 11px;
    color: rgba(255,255,255,0.4);
    text-decoration: none;
}

.dn-sidebar-footer a:hover { color: rgba(255,255,255,0.7); }

/* ============================================
   Main Content
   ============================================ */
.dn-main {
    margin-left: 240px;
    flex: 1;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

/* Top Bar */
.dn-topbar {
    background: var(--dn-card);
    border-bottom: 1px solid var(--dn-border);
    padding: 0 24px;
    height: 52px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    position: sticky;
    top: 0;
    z-index: 50;
}

.dn-breadcrumb {
    font-size: 13px;
    font-weight: 600;
    color: var(--dn-text);
}

.dn-topbar-right {
    display: flex;
    align-items: center;
    gap: 16px;
    font-size: 12px;
    color: var(--dn-text-muted);
}

.dn-topbar-divider {
    width: 1px;
    height: 20px;
    background: var(--dn-border);
}

.dn-topbar-tenant {
    font-weight: 600;
    color: var(--dn-text-secondary);
}

.dn-topbar-avatar {
    width: 30px;
    height: 30px;
    border-radius: 50%;
    background: var(--dn-red);
    color: #fff;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 11px;
    font-weight: 700;
}

/* Content Area */
.dn-content {
    padding: 20px 24px 40px;
    flex: 1;
}

.dn-tab-content {
    display: none;
    overflow: hidden;
}

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

/* ============================================
   Cards & Sections
   ============================================ */
.dn-section-title {
    font-size: 14px;
    font-weight: 700;
    color: var(--dn-text);
    margin-bottom: 14px;
    display: flex;
    align-items: center;
    gap: 8px;
}

.dn-card {
    background: var(--dn-card);
    border: 1px solid var(--dn-border);
    border-radius: var(--dn-radius);
    box-shadow: var(--dn-shadow);
    padding: 18px;
    margin-bottom: 16px;
}

.dn-grid {
    display: grid;
    gap: 16px;
}

.dn-grid-2 { grid-template-columns: repeat(2, 1fr); }
.dn-grid-3 { grid-template-columns: repeat(3, 1fr); }
.dn-grid-4 { grid-template-columns: repeat(4, 1fr); }
.dn-grid-6 { grid-template-columns: repeat(6, 1fr); }

/* ============================================
   Status Indicator
   ============================================ */
.dn-status-hero {
    display: flex;
    align-items: center;
    gap: 20px;
    padding: 16px 0;
}

.dn-status-circle {
    width: 56px;
    height: 56px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    position: relative;
}

.dn-status-circle::after {
    content: '';
    position: absolute;
    inset: -4px;
    border-radius: 50%;
    border: 2px solid currentColor;
    opacity: 0.3;
    animation: dn-pulse 2s ease-in-out infinite;
}

@keyframes dn-pulse {
    0%, 100% { transform: scale(1); opacity: 0.3; }
    50% { transform: scale(1.1); opacity: 0.1; }
}

.dn-status-circle.healthy { background: var(--dn-success); color: var(--dn-success); }
.dn-status-circle.degraded { background: var(--dn-warning); color: var(--dn-warning); }
.dn-status-circle.down { background: var(--dn-danger); color: var(--dn-danger); }

.dn-status-circle svg { color: #fff; }

.dn-status-info h3 {
    font-size: 18px;
    font-weight: 700;
}

.dn-status-info p {
    font-size: 12px;
    color: var(--dn-text-muted);
    margin-top: 2px;
}

/* ============================================
   Telemetry Gauge Cards
   ============================================ */
.dn-gauge-card {
    background: var(--dn-card);
    border: 1px solid var(--dn-border);
    border-radius: var(--dn-radius);
    padding: 14px 16px;
    text-align: center;
}

.dn-gauge-label {
    font-size: 11px;
    color: var(--dn-text-muted);
    text-transform: uppercase;
    letter-spacing: 0.5px;
    margin-bottom: 6px;
}

.dn-gauge-value {
    font-size: 24px;
    font-weight: 700;
    color: var(--dn-text);
    line-height: 1.1;
}

.dn-gauge-unit {
    font-size: 12px;
    color: var(--dn-text-muted);
    font-weight: 400;
}

.dn-gauge-card.danger { border-left: 3px solid var(--dn-danger); }
.dn-gauge-card.warning { border-left: 3px solid var(--dn-warning); }
.dn-gauge-card.success { border-left: 3px solid var(--dn-success); }

/* ============================================
   Device Info
   ============================================ */
.dn-device-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 12px;
}

.dn-device-field {
    padding: 10px 12px;
    background: var(--dn-bg);
    border-radius: var(--dn-radius-sm);
}

.dn-device-field label {
    display: block;
    font-size: 10px;
    color: var(--dn-text-muted);
    text-transform: uppercase;
    letter-spacing: 0.5px;
    margin-bottom: 3px;
}

.dn-device-field span {
    font-size: 13px;
    font-weight: 600;
    color: var(--dn-text);
}

/* ============================================
   Simulate Controls
   ============================================ */
.dn-controls {
    display: flex;
    align-items: center;
    gap: 12px;
    margin-bottom: 20px;
    flex-wrap: wrap;
}

.dn-btn {
    padding: 8px 18px;
    border-radius: var(--dn-radius-sm);
    font-size: 13px;
    font-weight: 600;
    border: none;
    cursor: pointer;
    transition: all 0.2s;
    display: inline-flex;
    align-items: center;
    gap: 6px;
}

.dn-btn:disabled {
    opacity: 0.5;
    cursor: not-allowed;
}

.dn-btn-primary {
    background: var(--dn-red);
    color: #fff;
}

.dn-btn-primary:hover:not(:disabled) { background: var(--dn-red-dark); }

.dn-btn-secondary {
    background: var(--dn-bg);
    color: var(--dn-text);
    border: 1px solid var(--dn-border);
}

.dn-btn-secondary:hover:not(:disabled) { background: #eee; }

.dn-btn-success {
    background: var(--dn-success);
    color: #fff;
}

.dn-select {
    padding: 8px 12px;
    border-radius: var(--dn-radius-sm);
    border: 1px solid var(--dn-border);
    font-size: 13px;
    background: #fff;
    color: var(--dn-text);
    cursor: pointer;
}

/* ============================================
   Badges
   ============================================ */
.dn-badge {
    display: inline-flex;
    align-items: center;
    padding: 3px 10px;
    border-radius: 20px;
    font-size: 11px;
    font-weight: 600;
    letter-spacing: 0.3px;
}

.dn-badge-success { background: var(--dn-success-bg); color: #059669; }
.dn-badge-warning { background: var(--dn-warning-bg); color: #D97706; }
.dn-badge-danger { background: var(--dn-danger-bg); color: #DC2626; }
.dn-badge-info { background: var(--dn-info-bg); color: #2563EB; }
.dn-badge-neutral { background: #F3F4F6; color: #4B5563; }

/* ============================================
   Timeline
   ============================================ */
.dn-timeline {
    position: relative;
    padding-left: 24px;
}

.dn-timeline::before {
    content: '';
    position: absolute;
    left: 7px;
    top: 4px;
    bottom: 4px;
    width: 2px;
    background: var(--dn-border);
}

.dn-timeline-item {
    position: relative;
    padding-bottom: 16px;
}

.dn-timeline-item:last-child { padding-bottom: 0; }

.dn-timeline-dot {
    position: absolute;
    left: -20px;
    top: 4px;
    width: 10px;
    height: 10px;
    border-radius: 50%;
    background: var(--dn-border);
    border: 2px solid var(--dn-card);
}

.dn-timeline-item[data-event="fault_injected"] .dn-timeline-dot { background: var(--dn-danger); }
.dn-timeline-item[data-event="detected"] .dn-timeline-dot { background: var(--dn-warning); }
.dn-timeline-item[data-event="diagnosed"] .dn-timeline-dot { background: var(--dn-info); }
.dn-timeline-item[data-event="healing_started"] .dn-timeline-dot,
.dn-timeline-item[data-event="healing_action"] .dn-timeline-dot { background: #8B5CF6; }
.dn-timeline-item[data-event="verified"] .dn-timeline-dot { background: var(--dn-success); }
.dn-timeline-item[data-event="resolved"] .dn-timeline-dot { background: var(--dn-success); }
.dn-timeline-item[data-event="escalated"] .dn-timeline-dot { background: var(--dn-danger); }
.dn-timeline-item[data-event="customer_notified"] .dn-timeline-dot,
.dn-timeline-item[data-event="rca_sent"] .dn-timeline-dot { background: #06B6D4; }

.dn-timeline-time {
    font-size: 10px;
    color: var(--dn-text-muted);
    font-family: 'Courier New', monospace;
}

.dn-timeline-event {
    font-size: 13px;
    font-weight: 600;
    color: var(--dn-text);
    margin-top: 1px;
}

.dn-timeline-detail {
    font-size: 12px;
    color: var(--dn-text-secondary);
    margin-top: 2px;
}

/* ============================================
   Incident Cards
   ============================================ */
.dn-incident-card {
    background: var(--dn-card);
    border: 1px solid var(--dn-border);
    border-radius: var(--dn-radius);
    padding: 16px;
    margin-bottom: 12px;
    cursor: pointer;
    transition: all 0.2s;
}

.dn-incident-card:hover {
    box-shadow: var(--dn-shadow-md);
    border-color: #d0d0d0;
}

.dn-incident-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin-bottom: 10px;
}

.dn-incident-id {
    font-weight: 700;
    font-size: 14px;
    font-family: 'Courier New', monospace;
}

.dn-incident-meta {
    display: flex;
    gap: 16px;
    font-size: 12px;
    color: var(--dn-text-muted);
}

.dn-incident-meta strong {
    color: var(--dn-text-secondary);
}

.dn-incident-summary {
    font-size: 12px;
    color: var(--dn-text-secondary);
    margin-top: 8px;
    line-height: 1.5;
}

.dn-incident-timeline-toggle {
    font-size: 11px;
    color: var(--dn-info);
    cursor: pointer;
    margin-top: 10px;
    font-weight: 600;
    user-select: none;
}

.dn-incident-timeline-toggle:hover { text-decoration: underline; }

.dn-incident-detail { display: none; margin-top: 12px; }
.dn-incident-detail.open { display: block; }

/* ============================================
   Table
   ============================================ */
.dn-table-wrap {
    overflow-x: auto;
}

.dn-table {
    width: 100%;
    border-collapse: collapse;
    font-size: 12px;
}

.dn-table th {
    text-align: left;
    padding: 10px 12px;
    background: var(--dn-bg);
    color: var(--dn-text-muted);
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.3px;
    font-size: 10px;
    border-bottom: 1px solid var(--dn-border);
}

.dn-table td {
    padding: 10px 12px;
    border-bottom: 1px solid var(--dn-border);
    color: var(--dn-text-secondary);
}

.dn-table tr:hover td { background: #FAFAFA; }

.dn-table .mono {
    font-family: 'Courier New', monospace;
    font-size: 11px;
}

/* ============================================
   KPI Cards
   ============================================ */
.dn-kpi-card {
    background: var(--dn-card);
    border: 1px solid var(--dn-border);
    border-radius: var(--dn-radius);
    padding: 18px;
    text-align: center;
}

.dn-kpi-value {
    font-size: 28px;
    font-weight: 800;
    color: var(--dn-text);
    line-height: 1;
}

.dn-kpi-label {
    font-size: 11px;
    color: var(--dn-text-muted);
    margin-top: 6px;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.dn-kpi-card.highlight { border-top: 3px solid var(--dn-red); }

/* ============================================
   Escalation Context
   ============================================ */
.dn-esc-section {
    margin-bottom: 14px;
}

.dn-esc-section h4 {
    font-size: 12px;
    font-weight: 700;
    color: var(--dn-text);
    margin-bottom: 6px;
    text-transform: uppercase;
    letter-spacing: 0.3px;
}

.dn-esc-list {
    list-style: none;
    padding: 0;
}

.dn-esc-list li {
    font-size: 12px;
    color: var(--dn-text-secondary);
    padding: 4px 0 4px 16px;
    position: relative;
}

.dn-esc-list li::before {
    content: '';
    position: absolute;
    left: 0;
    top: 10px;
    width: 6px;
    height: 6px;
    border-radius: 50%;
    background: var(--dn-red);
}

.dn-log-block {
    background: #1A1A1A;
    color: #22D3EE;
    font-family: 'Courier New', monospace;
    font-size: 11px;
    padding: 12px 14px;
    border-radius: var(--dn-radius-sm);
    overflow-x: auto;
    line-height: 1.6;
}

/* ============================================
   Escalation Actions
   ============================================ */
.dn-esc-actions {
    display: flex;
    gap: 8px;
    margin-top: 16px;
    padding-top: 16px;
    border-top: 1px solid var(--dn-border);
}

.dn-esc-btn {
    padding: 8px 16px;
    border: none;
    border-radius: var(--dn-radius-sm);
    font-size: 13px;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.2s;
}

.dn-esc-btn-primary { background: var(--dn-red); color: white; }
.dn-esc-btn-primary:hover { background: #C41920; }
.dn-esc-btn-secondary { background: var(--dn-bg); color: var(--dn-text); border: 1px solid var(--dn-border); }
.dn-esc-btn-secondary:hover { background: #E5E7EB; }
.dn-esc-btn-success { background: var(--dn-success); color: white; }
.dn-esc-btn-success:hover { background: #059669; }
.dn-esc-btn:disabled { opacity: 0.5; cursor: not-allowed; }

/* Modal */
.dn-modal {
    display: none;
    position: fixed;
    top: 0; left: 0; right: 0; bottom: 0;
    background: rgba(0, 0, 0, 0.5);
    z-index: 1000;
    align-items: center;
    justify-content: center;
}

.dn-modal.active { display: flex; }

.dn-modal-content {
    background: var(--dn-card);
    border-radius: var(--dn-radius);
    padding: 24px;
    width: 90%;
    max-width: 560px;
    max-height: 80vh;
    overflow-y: auto;
    box-shadow: 0 20px 60px rgba(0, 0, 0, 0.3);
}

.dn-modal-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 20px;
}

.dn-modal-title {
    font-size: 18px;
    font-weight: 600;
    color: var(--dn-text);
}

.dn-modal-close {
    background: none;
    border: none;
    font-size: 24px;
    cursor: pointer;
    color: var(--dn-text-muted);
    padding: 0;
    line-height: 1;
}

.dn-form-group { margin-bottom: 16px; }

.dn-form-label {
    display: block;
    font-size: 13px;
    font-weight: 500;
    color: var(--dn-text);
    margin-bottom: 6px;
}

.dn-form-input,
.dn-form-textarea {
    width: 100%;
    padding: 8px 12px;
    border: 1px solid var(--dn-border);
    border-radius: var(--dn-radius-sm);
    font-size: 13px;
    font-family: inherit;
    box-sizing: border-box;
}

.dn-form-textarea { min-height: 80px; resize: vertical; }

.dn-form-input:focus,
.dn-form-textarea:focus {
    outline: none;
    border-color: var(--dn-red);
    box-shadow: 0 0 0 2px rgba(237, 28, 36, 0.1);
}

.dn-form-footer {
    display: flex;
    gap: 8px;
    justify-content: flex-end;
    margin-top: 20px;
}

/* Operator notes */
.dn-operator-notes {
    margin-top: 12px;
    padding: 12px;
    background: #EFF6FF;
    border-left: 3px solid #3B82F6;
    border-radius: var(--dn-radius-sm);
}

.dn-note-item {
    font-size: 12px;
    color: var(--dn-text-secondary);
    margin-bottom: 8px;
    padding-bottom: 8px;
    border-bottom: 1px solid rgba(59, 130, 246, 0.15);
}

.dn-note-item:last-child { margin-bottom: 0; padding-bottom: 0; border-bottom: none; }

.dn-note-meta {
    font-size: 10px;
    color: var(--dn-text-muted);
    margin-bottom: 4px;
}

/* ============================================
   Notification Cards
   ============================================ */
.dn-notif-card {
    background: var(--dn-card);
    border: 1px solid var(--dn-border);
    border-radius: var(--dn-radius);
    padding: 14px 16px;
    margin-bottom: 10px;
}

.dn-notif-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin-bottom: 6px;
}

.dn-notif-subject {
    font-size: 13px;
    font-weight: 600;
    color: var(--dn-text);
}

.dn-notif-content {
    font-size: 12px;
    color: var(--dn-text-secondary);
    line-height: 1.5;
    white-space: pre-line;
    display: none;
    margin-top: 8px;
    padding: 10px 12px;
    background: var(--dn-bg);
    border-radius: var(--dn-radius-sm);
}

.dn-notif-content.open { display: block; }

.dn-notif-meta {
    font-size: 11px;
    color: var(--dn-text-muted);
    display: flex;
    gap: 12px;
    margin-top: 4px;
}

.dn-notif-toggle {
    font-size: 11px;
    color: var(--dn-info);
    cursor: pointer;
    font-weight: 600;
    margin-top: 6px;
}

.dn-notif-toggle:hover { text-decoration: underline; }

/* ============================================
   Chart Container
   ============================================ */
.dn-chart-container {
    position: relative;
    height: 260px;
    width: 100%;
}

.dn-chart-container canvas {
    width: 100% !important;
    height: 100% !important;
}

.dn-chart-small {
    height: 200px;
}

/* ============================================
   Cycle Progress (simulation animation)
   ============================================ */
.dn-cycle-progress {
    display: none;
    background: var(--dn-card);
    border: 1px solid var(--dn-border);
    border-radius: var(--dn-radius);
    padding: 18px;
    margin-bottom: 16px;
}

.dn-cycle-progress.active { display: block; }

.dn-cycle-steps {
    display: flex;
    align-items: center;
    gap: 4px;
    margin-top: 12px;
}

.dn-cycle-step {
    flex: 1;
    text-align: center;
    padding: 8px 4px;
    border-radius: var(--dn-radius-sm);
    font-size: 10px;
    font-weight: 600;
    color: var(--dn-text-muted);
    background: var(--dn-bg);
    transition: all 0.3s;
}

.dn-cycle-step.active {
    background: var(--dn-info-bg);
    color: var(--dn-info);
}

.dn-cycle-step.done {
    background: var(--dn-success-bg);
    color: #059669;
}

.dn-cycle-step.failed {
    background: var(--dn-danger-bg);
    color: #DC2626;
}

.dn-cycle-title {
    font-size: 14px;
    font-weight: 700;
}

/* ============================================
   Empty State
   ============================================ */
.dn-empty {
    text-align: center;
    padding: 40px;
    color: var(--dn-text-muted);
    font-size: 13px;
}

/* ============================================
   Loading Spinner
   ============================================ */
.dn-spinner {
    display: inline-block;
    width: 16px;
    height: 16px;
    border: 2px solid var(--dn-border);
    border-top: 2px solid var(--dn-red);
    border-radius: 50%;
    animation: dn-spin 0.6s linear infinite;
}

@keyframes dn-spin {
    to { transform: rotate(360deg); }
}

/* ============================================
   Responsive
   ============================================ */
@media (max-width: 1200px) {
    .dn-sidebar { width: 56px; }
    .dn-sidebar .dn-nav-item span,
    .dn-sidebar .dn-logo-title,
    .dn-sidebar .dn-logo-sub,
    .dn-sidebar .dn-sidebar-footer a { display: none; }
    .dn-main { margin-left: 56px; }
    .dn-grid-6 { grid-template-columns: repeat(3, 1fr); }
    .dn-device-grid { grid-template-columns: repeat(2, 1fr); }
}

@media (max-width: 768px) {
    .dn-grid-4 { grid-template-columns: repeat(2, 1fr); }
    .dn-grid-3 { grid-template-columns: repeat(2, 1fr); }
}