:root {
  color-scheme: light dark;
  --bg: #f8fafc;
  --surface: #ffffff;
  --surface-muted: #f1f5f9;
  --text: #0f172a;
  --muted: #475569;
  --muted-strong: #1e293b;
  --border: rgba(148, 163, 184, 0.35);
  --accent: #2563eb;
  --accent-strong: #1d4ed8;
  --accent-soft: rgba(37, 99, 235, 0.14);
  --shadow: 0 18px 35px rgba(15, 23, 42, 0.15);
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #020817;
    --surface: #0f172a;
    --surface-muted: #111c2f;
    --text: #e2e8f0;
    --muted: #cbd5f5;
    --muted-strong: #f8fafc;
    --border: rgba(148, 163, 184, 0.18);
    --accent: #60a5fa;
    --accent-strong: #3b82f6;
    --accent-soft: rgba(96, 165, 250, 0.22);
    --shadow: 0 14px 28px rgba(3, 14, 37, 0.55);
  }
}

:root[data-theme='light'] {
  color-scheme: light;
  --bg: #f8fafc;
  --surface: #ffffff;
  --surface-muted: #f1f5f9;
  --text: #0f172a;
  --muted: #475569;
  --muted-strong: #1e293b;
  --border: rgba(148, 163, 184, 0.35);
  --accent: #2563eb;
  --accent-strong: #1d4ed8;
  --accent-soft: rgba(37, 99, 235, 0.14);
  --shadow: 0 18px 35px rgba(15, 23, 42, 0.15);
}

:root[data-theme='dark'] {
  color-scheme: dark;
  --bg: #020817;
  --surface: #0f172a;
  --surface-muted: #111c2f;
  --text: #e2e8f0;
  --muted: #cbd5f5;
  --muted-strong: #f8fafc;
  --border: rgba(148, 163, 184, 0.18);
  --accent: #60a5fa;
  --accent-strong: #3b82f6;
  --accent-soft: rgba(96, 165, 250, 0.22);
  --shadow: 0 14px 28px rgba(3, 14, 37, 0.55);
}

body.nav-open {
  overflow: hidden;
}

.page-shell {
  display: grid;
  grid-template-columns: 260px 1fr;
  min-height: 100vh;
}

.brand {
  font-weight: 700;
  font-size: 1.2rem;
  letter-spacing: 0.02em;
  color: var(--muted-strong);
}

.sidebar {
  position: sticky;
  top: 0;
  height: 100vh;
  background: var(--surface);
  border-right: 1px solid var(--border);
  padding: 32px 24px;
  display: flex;
  flex-direction: column;
  overflow-y: auto;
}

.sidebar-inner {
  display: flex;
  flex-direction: column;
  gap: 32px;
  flex: 1;
}

.sidebar-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
}

.side-nav {
  display: grid;
  gap: 16px;
  font-size: 0.95rem;
}

.side-nav-group {
  display: grid;
  gap: 6px;
}

.side-nav-label {
  font-size: 0.7rem;
  font-weight: 700;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--muted);
  padding: 0;
}

.side-nav a {
  color: var(--muted);
  font-weight: 600;
  padding: 10px 12px;
  border-radius: 12px;
  transition: background-color 0.2s ease, color 0.2s ease;
}

.side-nav a:hover {
  color: var(--accent);
  background: var(--accent-soft);
}

.side-nav a[aria-current="page"] {
  color: var(--accent-strong);
  background: var(--accent-soft);
}

.sidebar-footer {
  margin-top: auto;
  padding-top: 16px;
  border-top: 1px solid var(--border);
  display: grid;
  gap: 8px;
}

.theme-select-label {
  font-size: 0.7rem;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--muted);
}

.theme-select {
  appearance: none;
  background: var(--surface-muted);
  border: 1px solid var(--border);
  color: var(--muted-strong);
  border-radius: 12px;
  padding: 10px 12px;
  font-weight: 600;
  font-size: 0.95rem;
  cursor: pointer;
  transition: border-color 0.2s ease, box-shadow 0.2s ease;
}

.theme-select:hover {
  border-color: var(--accent);
}

.theme-select:focus-visible {
  outline: none;
  border-color: var(--accent);
  box-shadow: 0 0 0 3px var(--accent-soft);
}

.page-content {
  display: flex;
  flex-direction: column;
  min-height: 100vh;
}

.mobile-header {
  display: none;
}

.menu-toggle,
.close-nav {
  background: var(--surface-muted);
  border: 1px solid var(--border);
  color: var(--muted-strong);
  border-radius: 999px;
  padding: 8px 18px;
  font-weight: 600;
  cursor: pointer;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  transition: border-color 0.2s ease, color 0.2s ease, background-color 0.2s ease;
}

.menu-toggle:hover,
.close-nav:hover {
  border-color: var(--accent);
  color: var(--accent);
}

.close-nav {
  display: none;
  margin-left: auto;
}

.nav-overlay {
  position: fixed;
  inset: 0;
  background: rgba(15, 23, 42, 0.45);
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.3s ease;
  z-index: 20;
}

body.nav-open .nav-overlay {
  opacity: 1;
  pointer-events: auto;
}

@media (max-width: 960px) {
  .page-shell {
    grid-template-columns: 1fr;
  }

  .sidebar {
    position: fixed;
    inset: 0 auto 0 0;
    width: min(320px, 84vw);
    max-width: 320px;
    border-right: none;
    border-bottom-right-radius: 24px;
    transform: translateX(-100%);
    transition: transform 0.3s ease;
    box-shadow: var(--shadow);
    z-index: 30;
  }

  body.nav-open .sidebar {
    transform: translateX(0);
  }

  .sidebar-inner {
    gap: 24px;
  }

  .close-nav {
    display: inline-flex;
  }

  .mobile-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 16px 24px;
    background: var(--surface);
    border-bottom: 1px solid var(--border);
    position: sticky;
    top: 0;
    z-index: 10;
  }
}

@media (min-width: 961px) {
  .nav-overlay {
    display: none;
  }
}