:root {
  --bg-main: #0b1120;
  --bg-card: #131c31;
  --bg-elevated: #1e293b;
  --bg-input: #0f172a;
  --border-color: #293548;
  --text-main: #f8fafc;
  --text-muted: #94a3b8;
  --primary: #38bdf8;
  --primary-hover: #0284c7;
  --accent: #10b981;
  --accent-hover: #059669;
  --warning: #f59e0b;
  --danger: #ef4444;
  --radius-md: 10px;
  --radius-lg: 14px;
}

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

body {
  margin: 0;
  font-family: system-ui, -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  background-color: var(--bg-main);
  color: var(--text-main);
  line-height: 1.5;
  min-height: 100vh;
}

.hidden {
  display: none !important;
}

.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  border: 0;
}

/* TOPBAR */
.topbar {
  position: sticky;
  inset-block-start: 0;
  z-index: 50;
  background: rgba(15, 23, 42, 0.92);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--border-color);
}

.topbar-inner {
  max-width: 1360px;
  margin: 0 auto;
  padding: 0.85rem 1.5rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  flex-wrap: wrap;
}

.brand {
  display: flex;
  align-items: center;
  gap: 0.75rem;
}

.brand-logo {
  width: 40px;
  height: 40px;
  border-radius: 10px;
  background: linear-gradient(135deg, #0284c7, #10b981);
  display: grid;
  place-items: center;
  font-weight: 800;
  font-size: 1.05rem;
  color: #fff;
}

.brand-title {
  display: block;
  font-weight: 800;
  font-size: 1.2rem;
  letter-spacing: -0.02em;
}

.brand-sub {
  display: block;
  font-size: 0.78rem;
  color: var(--text-muted);
}

.topbar-actions {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  flex-wrap: wrap;
}

.status-pill {
  display: inline-flex;
  align-items: center;
  gap: 0.45rem;
  padding: 0.3rem 0.75rem;
  border-radius: 999px;
  font-size: 0.78rem;
  font-weight: 600;
  background: var(--bg-elevated);
  border: 1px solid var(--border-color);
}

.status-pill .dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--warning);
}

.status-pill.status-ok .dot {
  background: var(--accent);
  box-shadow: 0 0 8px var(--accent);
}

.lang-switch {
  display: inline-flex;
  background: var(--bg-input);
  border: 1px solid var(--border-color);
  border-radius: 8px;
  overflow: hidden;
}

.lang-btn {
  background: transparent;
  color: var(--text-muted);
  border: none;
  padding: 0.35rem 0.65rem;
  font-size: 0.78rem;
  font-weight: 700;
  cursor: pointer;
}

.lang-btn.active {
  background: var(--primary);
  color: #0b1120;
}

.user-toolbar {
  display: flex;
  align-items: center;
  gap: 0.65rem;
}

.user-chip {
  font-size: 0.84rem;
  color: var(--text-main);
  padding: 0.3rem 0.65rem;
  background: var(--bg-elevated);
  border-radius: 6px;
}

.main-container {
  max-width: 1360px;
  margin: 0 auto;
  padding: 1.5rem;
}

/* AUTHENTICATION CARD & FORM VALIDATION (validate-input-after-interaction) */
.auth-wrapper {
  display: flex;
  justify-content: center;
  padding-block: 2rem;
}

.auth-card {
  width: 100%;
  max-width: 440px;
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 1.75rem;
  box-shadow: 0 18px 40px rgba(0, 0, 0, 0.45);
}

.auth-tabs {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 0.5rem;
  margin-bottom: 1.25rem;
  background: var(--bg-input);
  padding: 0.3rem;
  border-radius: 8px;
}

.auth-tab {
  background: transparent;
  color: var(--text-muted);
  border: none;
  padding: 0.55rem;
  border-radius: 6px;
  font-weight: 600;
  cursor: pointer;
}

.auth-tab.active {
  background: var(--bg-elevated);
  color: var(--text-main);
}

.auth-title {
  margin: 0 0 0.35rem;
  font-size: 1.35rem;
}

.auth-subtitle {
  margin: 0 0 1.25rem;
  font-size: 0.88rem;
  color: var(--text-muted);
}

.field {
  margin-bottom: 1rem;
}

.field label {
  display: block;
  font-weight: 600;
  font-size: 0.88rem;
  margin-bottom: 0.2rem;
}

.hint {
  display: block;
  color: var(--text-muted);
  font-size: 0.78rem;
  margin-bottom: 0.3rem;
}

.field input,
.select-input,
.search-input {
  width: 100%;
  padding: 0.65rem 0.8rem;
  border-radius: 8px;
  border: 1px solid var(--border-color);
  background: var(--bg-input);
  color: var(--text-main);
  font-size: 0.94rem;
}

.field input:focus,
.select-input:focus,
.search-input:focus {
  outline: 2px solid var(--primary);
  border-color: transparent;
}

.password-input-group {
  display: flex;
  gap: 0.4rem;
}

.btn-pwd-toggle {
  background: var(--bg-elevated);
  color: var(--text-main);
  border: 1px solid var(--border-color);
  border-radius: 8px;
  padding: 0 0.8rem;
  font-size: 0.8rem;
  cursor: pointer;
  white-space: nowrap;
}

.error-msg {
  display: none;
  color: #f87171;
  font-size: 0.82rem;
  margin-top: 0.3rem;
}

/* validate-input-after-interaction (:user-invalid & :user-valid + fallback) */
input:user-invalid,
input.user-invalid-fallback {
  border-color: #ef4444;
  background-color: rgba(239, 68, 68, 0.1);
}

input:user-invalid + .error-msg,
input.user-invalid-fallback + .error-msg,
.password-input-group:has(input:user-invalid) + .error-msg,
.password-input-group:has(input.user-invalid-fallback) + .error-msg {
  display: block;
}

input:user-valid,
input.user-valid-fallback {
  border-color: #10b981;
}

.form-alert {
  padding: 0.65rem 0.85rem;
  border-radius: 8px;
  font-size: 0.85rem;
  margin-bottom: 1rem;
  background: rgba(239, 68, 68, 0.15);
  border: 1px solid var(--danger);
  color: #fca5a5;
}

.form-alert.success {
  background: rgba(16, 185, 129, 0.15);
  border-color: var(--accent);
  color: #6ee7b7;
}

/* BUTTONS */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.4rem;
  padding: 0.6rem 1.1rem;
  border-radius: 8px;
  border: none;
  font-weight: 600;
  font-size: 0.9rem;
  cursor: pointer;
  transition: background-color 0.15s ease, transform 0.1s ease;
}

.btn:active {
  transform: scale(0.98);
}

.btn-primary {
  background: var(--primary);
  color: #0b1120;
}

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

.btn-accent {
  background: var(--accent);
  color: #06281e;
}

.btn-accent:hover {
  background: var(--accent-hover);
  color: #fff;
}

.btn-danger {
  background: rgba(239, 68, 68, 0.18);
  color: #fca5a5;
  border: 1px solid rgba(239, 68, 68, 0.4);
}

.btn-ghost {
  background: var(--bg-elevated);
  color: var(--text-main);
  border: 1px solid var(--border-color);
}

.btn-sm {
  padding: 0.35rem 0.7rem;
  font-size: 0.8rem;
}

.btn-block {
  width: 100%;
}

/* SUBNAV TABS */
.subnav {
  display: flex;
  gap: 0.5rem;
  flex-wrap: wrap;
  margin-bottom: 1.5rem;
  border-bottom: 1px solid var(--border-color);
  padding-bottom: 0.75rem;
}

.subnav-btn {
  background: var(--bg-card);
  color: var(--text-muted);
  border: 1px solid var(--border-color);
  padding: 0.55rem 1rem;
  border-radius: 8px;
  font-weight: 600;
  font-size: 0.88rem;
  cursor: pointer;
}

.subnav-btn.active {
  background: var(--primary);
  color: #0b1120;
  border-color: var(--primary);
}

.section-header {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  gap: 1rem;
  flex-wrap: wrap;
  margin-bottom: 1.25rem;
}

.section-title {
  margin: 0 0 0.25rem;
  font-size: 1.4rem;
}

.section-desc {
  margin: 0;
  color: var(--text-muted);
  font-size: 0.9rem;
}

.filter-bar {
  display: grid;
  grid-template-columns: 1fr 240px;
  gap: 0.75rem;
  margin-bottom: 1.25rem;
}

@media (max-width: 640px) {
  .filter-bar {
    grid-template-columns: 1fr;
  }
}

/* DEVICES & CATALOG GRIDS */
.devices-grid,
.catalog-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(360px, 1fr));
  gap: 1.25rem;
}

.device-card,
.catalog-card,
.panel-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 1.25rem;
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

.device-card-header {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  gap: 0.75rem;
}

.device-title {
  margin: 0;
  font-size: 1.12rem;
  font-weight: 700;
}

.device-subtitle {
  font-size: 0.8rem;
  color: var(--text-muted);
}

.badge {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  padding: 0.22rem 0.6rem;
  border-radius: 999px;
  font-size: 0.74rem;
  font-weight: 700;
}

.badge-online {
  background: rgba(16, 185, 129, 0.18);
  color: #34d399;
  border: 1px solid rgba(16, 185, 129, 0.4);
}

.badge-offline {
  background: rgba(148, 163, 184, 0.15);
  color: #cbd5e1;
  border: 1px solid rgba(148, 163, 184, 0.3);
}

.badge-heat {
  background: rgba(249, 115, 22, 0.2);
  color: #fb923c;
  border: 1px solid rgba(249, 115, 22, 0.45);
}

.metrics-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 0.65rem;
}

.metric-box {
  background: var(--bg-input);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 0.75rem;
}

.metric-label {
  display: block;
  font-size: 0.75rem;
  color: var(--text-muted);
}

.metric-value {
  display: block;
  font-size: 1.35rem;
  font-weight: 800;
  color: var(--primary);
  margin-top: 0.15rem;
}

.controls-box {
  background: rgba(15, 23, 42, 0.65);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 0.85rem;
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
}

.control-row {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 0.5rem;
  flex-wrap: wrap;
}

.control-label {
  font-size: 0.84rem;
  font-weight: 600;
}

.stepper-group {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
}

.stepper-val {
  min-width: 64px;
  text-align: center;
  font-weight: 700;
  font-size: 0.95rem;
}

.action-chips {
  display: flex;
  flex-wrap: wrap;
  gap: 0.45rem;
}

/* OTA PROGRESS BAR */
.ota-bar-box {
  background: var(--bg-input);
  border: 1px solid var(--border-color);
  border-radius: 8px;
  padding: 0.65rem 0.8rem;
  font-size: 0.8rem;
}

.ota-header-row {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 0.5rem;
  flex-wrap: wrap;
}

.progress-track {
  width: 100%;
  height: 8px;
  background: var(--bg-elevated);
  border-radius: 999px;
  overflow: hidden;
  margin-top: 0.45rem;
}

.progress-fill {
  height: 100%;
  background: linear-gradient(90deg, var(--primary), var(--accent));
  transition: width 0.3s ease;
}

/* RESPONSIVE TABLE (modern-web-guidance: responsive-table) */
.table-wrapper {
  overflow: auto;
  max-inline-size: 100%;
  max-block-size: min(560px, 80vh);
  container-type: inline-size;
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
}

table {
  width: 100%;
  border-collapse: separate;
  border-spacing: 0;
  font-size: 0.88rem;
}

thead {
  position: sticky;
  inset-block-start: 0;
  z-index: 2;
  background: var(--bg-elevated);
}

th,
td {
  padding: 0.75rem 1rem;
  text-align: left;
  border-bottom: 1px solid var(--border-color);
}

tbody th {
  position: sticky;
  inset-inline-start: 0;
  background: var(--bg-card);
  font-weight: 600;
  z-index: 1;
}

@container (width < 600px) {
  table,
  thead,
  tbody,
  tr,
  th,
  td {
    display: block;
  }

  thead {
    /* MANDATORY: Hide column header from layout and screen readers. */
    display: none;
  }

  tr {
    margin-block-end: 1rem;
    border: 1px solid var(--border-color);
  }

  tbody th {
    position: sticky;
    inset-block-start: 0;
    z-index: 2;
    background: var(--bg-elevated);
  }

  td:nth-child(2)::before {
    content: var(--label-2, "") ": ";
    font-weight: 700;
    color: var(--text-muted);
  }

  td:nth-child(3)::before {
    content: var(--label-3, "") ": ";
    font-weight: 700;
    color: var(--text-muted);
  }

  td:nth-child(4)::before {
    content: var(--label-4, "") ": ";
    font-weight: 700;
    color: var(--text-muted);
  }

  td:nth-child(5)::before {
    content: var(--label-5, "") ": ";
    font-weight: 700;
    color: var(--text-muted);
  }

  td:nth-child(6)::before {
    content: var(--label-6, "") ": ";
    font-weight: 700;
    color: var(--text-muted);
  }

  td:nth-child(7)::before {
    content: var(--label-7, "") ": ";
    font-weight: 700;
    color: var(--text-muted);
  }
}

/* ADMIN TWO COLUMN LAYOUT */
.admin-two-col {
  display: grid;
  grid-template-columns: 1.2fr 1fr;
  gap: 1.5rem;
}

@media (max-width: 920px) {
  .admin-two-col {
    grid-template-columns: 1fr;
  }
}

.form-row-2 {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 0.75rem;
}

.migration-box {
  background: var(--bg-input);
  border: 1px solid var(--border-color);
  border-radius: 8px;
  padding: 0.85rem;
  font-size: 0.85rem;
}

.migration-list {
  list-style: none;
  padding: 0;
  margin: 0;
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}

.migration-list li {
  background: var(--bg-input);
  padding: 0.55rem 0.75rem;
  border-radius: 6px;
  border: 1px solid var(--border-color);
  font-size: 0.82rem;
}

/* LIGHT DISMISS DIALOGS (modern-web-guidance: light-dismiss-a-dialog) */
dialog.modal-dialog {
  background: var(--bg-card);
  color: var(--text-main);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 0;
  width: min(92vw, 500px);
  box-shadow: 0 24px 50px rgba(0, 0, 0, 0.65);
}

dialog::backdrop {
  background-color: rgba(0, 0, 0, 0.55);
  backdrop-filter: blur(2px);
}

.modal-content {
  padding: 1.5rem;
}

.modal-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 1rem;
}

.modal-header h3 {
  margin: 0;
}

.btn-close {
  background: transparent;
  color: var(--text-muted);
  border: none;
  font-size: 1.15rem;
  cursor: pointer;
}

.modal-footer {
  display: flex;
  justify-content: flex-end;
  gap: 0.6rem;
  margin-top: 1.25rem;
}

.token-banner {
  background: var(--bg-input);
  border: 1px dashed var(--primary);
  border-radius: 10px;
  padding: 1rem;
  text-align: center;
  margin-bottom: 1rem;
}

.token-label {
  display: block;
  font-size: 0.78rem;
  color: var(--text-muted);
  margin-bottom: 0.35rem;
}

.token-value-row {
  display: flex;
  justify-content: center;
  align-items: center;
  gap: 0.65rem;
}

.token-code {
  font-size: 1.35rem;
  font-weight: 800;
  color: var(--primary);
  letter-spacing: 0.04em;
}

.onboarding-steps {
  padding-left: 1.25rem;
  font-size: 0.88rem;
  color: var(--text-main);
  line-height: 1.65;
}

.waiting-indicator {
  display: flex;
  align-items: center;
  gap: 0.65rem;
  padding: 0.75rem;
  background: rgba(56, 189, 248, 0.1);
  border-radius: 8px;
  font-size: 0.85rem;
  color: var(--primary);
  margin-top: 1rem;
}

.spinner {
  width: 16px;
  height: 16px;
  border: 2px solid var(--primary);
  border-top-color: transparent;
  border-radius: 50%;
  animation: spin 0.8s linear infinite;
}

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