.app-shell {
  position: relative;
  min-height: 100vh;
}

.app-background {
  position: fixed;
  inset: 0;
  z-index: -2;
  pointer-events: none;
  background: linear-gradient(180deg, var(--bg-canvas), var(--bg));
}

.app-background::before,
.app-background::after {
  content: "";
  position: absolute;
  inset: 0;
}

.app-background::before {
  background-image:
    linear-gradient(var(--grid-line) 1px, transparent 1px),
    linear-gradient(90deg, var(--grid-line) 1px, transparent 1px);
  background-size: 42px 42px;
  mask-image: linear-gradient(180deg, black, transparent 92%);
}

.app-background::after {
  display: none;
}

.page-shell {
  width: 100%;
  max-width: calc(var(--page-width) + (var(--page-gutter) * 2));
  margin: 0 auto;
  padding: 1rem var(--page-gutter) 3rem;
  display: grid;
  gap: 1rem;
}

.page-shell > * {
  animation: fade-up 0.55s cubic-bezier(0.22, 1, 0.36, 1) both;
}

.page-shell > *:nth-child(2) {
  animation-delay: 0.04s;
}

.page-shell > *:nth-child(3) {
  animation-delay: 0.08s;
}

.page-shell > *:nth-child(4) {
  animation-delay: 0.12s;
}

.page-shell > *:nth-child(5) {
  animation-delay: 0.16s;
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 40;
  padding: 0.55rem 0 0;
}

.site-header__inner,
.site-footer__inner {
  width: 100%;
  max-width: calc(var(--page-width) + (var(--page-gutter) * 2));
  margin: 0 auto;
  padding-left: var(--page-gutter);
  padding-right: var(--page-gutter);
  box-sizing: border-box;
}

.site-header__inner {
  position: relative;
  display: grid;
  grid-template-columns: auto minmax(0, 1fr) auto;
  align-items: center;
  gap: 0.75rem 1rem;
  padding: 0.55rem 0.7rem;
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  background: var(--surface-overlay);
  backdrop-filter: blur(14px);
  box-shadow: var(--header-shadow);
}

.site-header__inner::before {
  display: none;
}

.site-header__actions,
.site-nav,
.summary-meta,
.inline-meta {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  flex-wrap: wrap;
}

.site-footer {
  padding: 0 0 1.6rem;
}

.site-footer__inner {
  display: flex;
  justify-content: space-between;
  gap: 1rem;
  align-items: center;
  padding-top: 1rem;
  border-top: 1px solid var(--line-subtle);
  color: var(--text-muted);
  font-size: 0.92rem;
}

.site-footer__links {
  display: flex;
  gap: 1rem;
  flex-wrap: wrap;
}

.single-column {
  width: min(760px, 100%);
  margin: 0 auto;
}

.section-card {
  position: relative;
  overflow: hidden;
  border: 1px solid var(--border);
  border-radius: var(--radius-xl);
  background: var(--surface-card);
  box-shadow: var(--shadow-sm);
  isolation: isolate;
}

.section-card::before,
.section-card::after {
  content: "";
  position: absolute;
  pointer-events: none;
}

.section-card::before {
  inset: 0 auto 0 0;
  width: 2px;
  height: auto;
  background: var(--primary);
  opacity: 0.65;
}

.section-card::after {
  display: none;
}

.section-card__header,
.section-card__body {
  position: relative;
  z-index: 1;
}

.section-card__header {
  display: flex;
  justify-content: space-between;
  gap: 0.8rem 1.25rem;
  align-items: flex-start;
  padding: 1rem 1.1rem 0;
}

.section-card__header h2 {
  margin-bottom: 0.25rem;
}

.section-card__eyebrow {
  margin-bottom: 0.38rem;
  color: var(--primary);
  font-size: 0.74rem;
  font-weight: 700;
  letter-spacing: 0.16em;
  text-transform: uppercase;
}

.section-card__subtitle {
  max-width: 62rem;
  color: var(--text-muted);
}

.section-card__actions {
  display: flex;
  gap: 0.75rem;
  flex-wrap: wrap;
}

.section-card__body {
  padding: 0.95rem 1.1rem 1.1rem;
}

.metrics-grid {
  display: grid;
  gap: 0.75rem;
  grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
}

.metrics-grid--compact {
  grid-template-columns: repeat(auto-fit, minmax(160px, 1fr));
}

.technical-grid,
.timeline-list,
.recommendation-list {
  display: grid;
  gap: 0.75rem;
}

.findings-grid,
.feature-grid,
.trust-grid,
.change-list {
  display: grid;
  gap: 0.75rem;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
}

.page-auth .single-column .section-card,
.page-monitoring .page-shell > .section-card:first-child,
.page-monitoring_plus .page-shell > .section-card:first-child,
.page-discovery .page-shell > .section-card:first-child,
.page-history .page-shell > .section-card:first-child {
  border-color: var(--border-accent);
  background: var(--highlight-panel);
}

@keyframes fade-up {
  from {
    opacity: 0;
    transform: translateY(14px);
  }

  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@media (max-width: 1120px) {
  .site-header__inner {
    grid-template-columns: 1fr;
  }

  .site-nav {
    justify-content: flex-start;
  }

  .site-header__actions {
    justify-content: flex-start;
  }
}

@media (max-width: 820px) {
  .site-header {
    position: static;
  }

  .site-header__inner,
  .site-footer__inner,
  .section-card__header {
    grid-template-columns: 1fr;
    flex-direction: column;
    align-items: stretch;
  }

  .section-card__header,
  .section-card__body {
    padding-left: 1.2rem;
    padding-right: 1.2rem;
  }
}

@media (max-width: 640px) {
  .page-shell {
    padding-top: 0.75rem;
    padding-bottom: 4rem;
  }

  .site-header__inner {
    gap: 0.6rem;
  }

  .site-nav {
    display: grid;
    width: 100%;
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 0.45rem;
  }

  .site-header__actions {
    display: grid;
    width: 100%;
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 0.45rem;
  }

  .site-nav a,
  .site-header__actions .button,
  .site-header__actions .inline-form,
  .site-header__actions .theme-toggle {
    width: 100%;
    min-height: 2.2rem;
  }

  .site-header__actions .button,
  .site-header__actions .inline-form .button {
    justify-content: center;
  }

  .site-footer__inner,
  .summary-meta,
  .inline-meta {
    flex-direction: column;
    align-items: flex-start;
  }
}

@media (min-width: 520px) and (max-width: 640px) {
  .site-nav {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
}