:root {
  --bg-canvas: hsl(216 26% 6.5%);
  --bg-elevated: hsl(216 21% 10%);
  --bg-elevated-hover: hsl(216 20% 12.5%);
  --bg-well: hsl(218 28% 5%);
  --border-hairline: hsl(215 16% 17%);
  --border-strong: hsl(215 15% 24%);

  --text-primary: hsl(210 24% 96%);
  --text-secondary: hsl(214 14% 68%);
  --text-muted: hsl(215 12% 48%);

  --accent: hsl(158 64% 50%);
  --accent-hover: hsl(158 68% 56%);
  --accent-ink: hsl(218 32% 7%);
  --accent-soft: hsl(158 64% 50% / 0.12);

  --amber: hsl(38 92% 58%);
  --amber-soft: hsl(38 92% 58% / 0.13);

  --crimson: hsl(4 80% 62%);
  --crimson-soft: hsl(4 80% 62% / 0.13);

  --font-display: 'Space Grotesk', -apple-system, BlinkMacSystemFont, sans-serif;
  --font-sans: 'Plus Jakarta Sans', -apple-system, BlinkMacSystemFont, sans-serif;
  --font-mono: 'JetBrains Mono', ui-monospace, SFMono-Regular, Menlo, monospace;

  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-lg: 16px;

  --shadow-surface:
    inset 0 1px 0 hsl(0 0% 100% / 0.04),
    0 12px 32px -12px hsl(220 45% 2% / 0.65);
  --ease-snappy: cubic-bezier(0.22, 1, 0.36, 1);
}

*,
*::before,
*::after {
  box-sizing: border-box;
}

html {
  color-scheme: dark;
  -webkit-text-size-adjust: 100%;
  scroll-behavior: smooth;
}

body {
  margin: 0;
  min-height: 100vh;
  background-color: var(--bg-canvas);
  background-image:
    radial-gradient(ellipse 90% 45% at 50% -12%, hsl(160 45% 18% / 0.22), transparent 68%),
    url("data:image/svg+xml,%3Csvg viewBox='0 0 160 160' xmlns='http://www.w3.org/2000/svg'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.85' numOctaves='2' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23n)' opacity='0.025'/%3E%3C/svg%3E");
  color: var(--text-primary);
  font-family: var(--font-sans);
  font-size: 15px;
  line-height: 1.55;
  -webkit-font-smoothing: antialiased;
}

/* Shell & Navigation */
.app-shell {
  max-width: 1060px;
  margin: 0 auto;
  padding: 24px 20px 72px;
}

.topbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  padding-bottom: 20px;
  border-bottom: 1px solid var(--border-hairline);
  flex-wrap: wrap;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  text-decoration: none;
  color: var(--text-primary);
}

.brand-mark {
  width: 34px;
  height: 34px;
  flex-shrink: 0;
}

.brand-title {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 1.15rem;
  letter-spacing: -0.025em;
}

.brand-sub {
  display: block;
  font-size: 0.76rem;
  color: var(--text-muted);
  letter-spacing: 0.01em;
}

.topbar-controls {
  display: flex;
  align-items: center;
  gap: 10px;
  flex-wrap: wrap;
}

.conn-indicator {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 7px 12px;
  border-radius: var(--radius-sm);
  background: var(--bg-elevated);
  border: 1px solid var(--border-hairline);
  color: var(--text-secondary);
  font-size: 0.81rem;
  font-weight: 500;
  cursor: pointer;
  transition: background-color 160ms var(--ease-snappy), border-color 160ms var(--ease-snappy);
}

.conn-indicator:hover {
  background: var(--bg-elevated-hover);
  border-color: var(--border-strong);
}

.status-dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--amber);
  flex-shrink: 0;
}

.status-dot.is-live {
  background: var(--accent);
}

.status-dot.is-paused {
  background: var(--amber);
}

/* Masthead & Primary Tabs */
.masthead {
  padding: 28px 0 22px;
  display: flex;
  align-items: flex-end;
  justify-content: space-between;
  gap: 24px;
  flex-wrap: wrap;
}

.masthead h1 {
  margin: 0 0 8px;
  font-family: var(--font-display);
  font-size: clamp(1.65rem, 3.2vw, 2.25rem);
  font-weight: 700;
  letter-spacing: -0.032em;
  line-height: 1.15;
}

.masthead p {
  margin: 0;
  max-width: 60ch;
  color: var(--text-secondary);
  font-size: 0.96rem;
}

.pause-bar {
  display: flex;
  align-items: center;
  gap: 8px;
  flex-wrap: wrap;
}

.nav-tabs {
  display: flex;
  gap: 6px;
  padding: 5px;
  background: var(--bg-well);
  border: 1px solid var(--border-hairline);
  border-radius: var(--radius-md);
  margin-bottom: 26px;
  overflow-x: auto;
}

.tab-btn {
  flex: 1 1 auto;
  min-width: max-content;
  appearance: none;
  background: transparent;
  border: 0;
  color: var(--text-secondary);
  font-family: var(--font-sans);
  font-size: 0.88rem;
  font-weight: 600;
  padding: 10px 16px;
  border-radius: var(--radius-sm);
  cursor: pointer;
  transition: color 160ms var(--ease-snappy), background-color 160ms var(--ease-snappy);
}

.tab-btn:hover {
  color: var(--text-primary);
}

.tab-btn[aria-selected="true"] {
  background: var(--bg-elevated);
  color: var(--text-primary);
  box-shadow: inset 0 1px 0 hsl(0 0% 100% / 0.06);
}

.view-panel {
  display: none;
  animation: fadeSlide 200ms var(--ease-snappy);
}

.view-panel.is-active {
  display: block;
}

@keyframes fadeSlide {
  from {
    opacity: 0;
    transform: translateY(4px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

/* Telemetry Strip */
.telemetry-strip {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  background: var(--bg-elevated);
  border: 1px solid var(--border-hairline);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-surface);
  margin-bottom: 24px;
  overflow: hidden;
}

.metric-cell {
  padding: 18px 20px;
  border-right: 1px solid var(--border-hairline);
}

.metric-cell:last-child {
  border-right: 0;
}

.metric-label {
  display: block;
  font-size: 0.76rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--text-muted);
  margin-bottom: 6px;
}

.metric-value {
  font-family: var(--font-mono);
  font-size: 1.45rem;
  font-weight: 600;
  letter-spacing: -0.02em;
  color: var(--text-primary);
}

.metric-sub {
  display: block;
  margin-top: 3px;
  font-size: 0.78rem;
  color: var(--text-secondary);
}

/* Panels & Sections */
.split-layout {
  display: grid;
  grid-template-columns: 1.2fr 1fr;
  gap: 20px;
  align-items: start;
}

.surface-block {
  background: var(--bg-elevated);
  border: 1px solid var(--border-hairline);
  border-radius: var(--radius-lg);
  padding: 24px;
  box-shadow: var(--shadow-surface);
  margin-bottom: 20px;
}

.section-head {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 16px;
  margin-bottom: 18px;
  flex-wrap: wrap;
}

.section-head h2 {
  margin: 0 0 4px;
  font-family: var(--font-display);
  font-size: 1.15rem;
  font-weight: 600;
  letter-spacing: -0.02em;
}

.section-head p {
  margin: 0;
  color: var(--text-secondary);
  font-size: 0.87rem;
}

/* Forms, Inputs & Buttons */
.input-row {
  display: flex;
  gap: 10px;
  flex-wrap: wrap;
}

.text-input,
.select-input {
  flex: 1 1 240px;
  min-width: 0;
  background: var(--bg-well);
  border: 1px solid var(--border-hairline);
  border-radius: var(--radius-sm);
  color: var(--text-primary);
  font-family: var(--font-mono);
  font-size: 0.86rem;
  padding: 11px 14px;
  transition: border-color 150ms var(--ease-snappy);
}

.text-input::placeholder {
  color: var(--text-muted);
}

.text-input:focus,
.select-input:focus {
  outline: none;
  border-color: var(--text-secondary);
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  appearance: none;
  border: 1px solid var(--border-hairline);
  background: var(--bg-elevated-hover);
  color: var(--text-primary);
  font-family: var(--font-sans);
  font-size: 0.86rem;
  font-weight: 600;
  padding: 10px 16px;
  border-radius: var(--radius-sm);
  cursor: pointer;
  text-decoration: none;
  white-space: nowrap;
  transition: transform 120ms var(--ease-snappy), background-color 150ms var(--ease-snappy), border-color 150ms var(--ease-snappy);
}

.btn:hover {
  background: hsl(216 18% 16%);
  border-color: var(--border-strong);
}

.btn:active {
  transform: translateY(1px);
}

.btn-primary {
  background: var(--accent);
  border-color: transparent;
  color: var(--accent-ink);
}

.btn-primary:hover {
  background: var(--accent-hover);
  border-color: transparent;
}

.btn-subtle {
  padding: 7px 11px;
  font-size: 0.79rem;
}

.btn-danger {
  color: var(--crimson);
}

/* Filter Category Rows (Flat Divided List — No Nested Cards) */
.rule-list {
  list-style: none;
  margin: 0;
  padding: 0;
  border-top: 1px solid var(--border-hairline);
}

.rule-item {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  padding: 15px 0;
  border-bottom: 1px solid var(--border-hairline);
}

.rule-item-title {
  display: block;
  font-weight: 600;
  font-size: 0.93rem;
  margin-bottom: 2px;
}

.rule-item-desc {
  display: block;
  font-size: 0.82rem;
  color: var(--text-secondary);
}

/* Accessible Toggle Switch */
.switch {
  position: relative;
  display: inline-block;
  width: 44px;
  height: 24px;
  flex-shrink: 0;
}

.switch input {
  opacity: 0;
  width: 0;
  height: 0;
}

.switch-track {
  position: absolute;
  inset: 0;
  background: var(--bg-well);
  border: 1px solid var(--border-strong);
  border-radius: 999px;
  cursor: pointer;
  transition: background-color 160ms var(--ease-snappy), border-color 160ms var(--ease-snappy);
}

.switch-track::before {
  content: '';
  position: absolute;
  width: 18px;
  height: 18px;
  left: 2px;
  top: 2px;
  border-radius: 50%;
  background: var(--text-secondary);
  transition: transform 160ms var(--ease-snappy), background-color 160ms var(--ease-snappy);
}

.switch input:checked + .switch-track {
  background: var(--accent-soft);
  border-color: var(--accent);
}

.switch input:checked + .switch-track::before {
  transform: translateX(20px);
  background: var(--accent);
}

/* Result Readouts & Code Copy Blocks */
.result-well {
  margin-top: 16px;
  padding: 16px;
  background: var(--bg-well);
  border: 1px solid var(--border-hairline);
  border-radius: var(--radius-md);
}

.result-well[hidden] {
  display: none;
}

.verdict-tag {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-family: var(--font-mono);
  font-size: 0.76rem;
  font-weight: 600;
  padding: 4px 9px;
  border-radius: 6px;
  text-transform: uppercase;
  letter-spacing: 0.04em;
}

.verdict-safe {
  background: var(--accent-soft);
  color: var(--accent);
}

.verdict-blocked {
  background: var(--crimson-soft);
  color: var(--crimson);
}

.verdict-warn {
  background: var(--amber-soft);
  color: var(--amber);
}

.mono-box {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  background: var(--bg-well);
  border: 1px solid var(--border-hairline);
  border-radius: var(--radius-sm);
  padding: 11px 14px;
  margin-top: 10px;
  overflow-x: auto;
}

.mono-box code {
  font-family: var(--font-mono);
  font-size: 0.82rem;
  color: var(--text-primary);
  word-break: break-all;
}

.chip-group {
  display: flex;
  flex-wrap: wrap;
  gap: 7px;
  margin-top: 10px;
}

.chip {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 4px 10px;
  border-radius: 6px;
  background: var(--bg-elevated);
  border: 1px solid var(--border-hairline);
  font-family: var(--font-mono);
  font-size: 0.77rem;
  color: var(--text-secondary);
}

.chip button {
  background: none;
  border: 0;
  color: var(--text-muted);
  cursor: pointer;
  padding: 0 2px;
  font-size: 0.9rem;
}

.chip button:hover {
  color: var(--crimson);
}

/* Device Provisioning Sections */
.device-step-list {
  margin: 12px 0 16px;
  padding-left: 20px;
  color: var(--text-secondary);
  font-size: 0.88rem;
}

.device-step-list li {
  margin-bottom: 6px;
}

/* Live DNS Query Table */
.table-wrap {
  overflow-x: auto;
  border-top: 1px solid var(--border-hairline);
}

.log-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.84rem;
}

.log-table th {
  text-align: left;
  padding: 11px 12px;
  color: var(--text-muted);
  font-weight: 600;
  font-size: 0.75rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  border-bottom: 1px solid var(--border-hairline);
}

.log-table td {
  padding: 11px 12px;
  border-bottom: 1px solid var(--border-hairline);
  vertical-align: middle;
}

.log-domain {
  font-family: var(--font-mono);
  font-size: 0.83rem;
  word-break: break-all;
}

/* Modal Dialog */
.modal-backdrop {
  position: fixed;
  inset: 0;
  background: hsl(220 40% 3% / 0.78);
  backdrop-filter: blur(6px);
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 20px;
  z-index: 100;
}

.modal-backdrop[hidden] {
  display: none;
}

.modal-dialog {
  width: 100%;
  max-width: 480px;
  background: var(--bg-elevated);
  border: 1px solid var(--border-strong);
  border-radius: var(--radius-lg);
  padding: 24px;
  box-shadow: var(--shadow-surface);
}

.modal-dialog h2 {
  margin: 0 0 6px;
  font-family: var(--font-display);
  font-size: 1.2rem;
}

.field-label {
  display: block;
  font-size: 0.8rem;
  font-weight: 600;
  color: var(--text-secondary);
  margin: 14px 0 6px;
}

/* Toast Notification */
.toast {
  position: fixed;
  bottom: 22px;
  right: 22px;
  background: var(--bg-elevated);
  border: 1px solid var(--border-strong);
  color: var(--text-primary);
  padding: 11px 16px;
  border-radius: var(--radius-sm);
  font-size: 0.85rem;
  font-weight: 500;
  box-shadow: var(--shadow-surface);
  z-index: 120;
  transition: opacity 160ms var(--ease-snappy), transform 160ms var(--ease-snappy);
}

.toast[hidden] {
  display: none;
}

/* Responsive Breakpoints */
@media (max-width: 860px) {
  .telemetry-strip {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
  .metric-cell:nth-child(2) {
    border-right: 0;
  }
  .metric-cell:nth-child(1),
  .metric-cell:nth-child(2) {
    border-bottom: 1px solid var(--border-hairline);
  }
  .split-layout {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 520px) {
  .app-shell {
    padding: 16px 14px 56px;
  }
  .surface-block {
    padding: 18px;
  }
  .input-row .btn {
    width: 100%;
  }
}