/* AI Ops Assistant v2.0 - Layout */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

html, body {
  height: 100%;
  font-family: var(--font-family);
  font-size: 14px;
  color: var(--text-primary);
  background: var(--bg-secondary);
  -webkit-font-smoothing: antialiased;
}

a { color: var(--text-link); text-decoration: none; }
a:hover { text-decoration: underline; }

/* ── App Shell ─────────────────────────── */
.app-shell {
  display: flex;
  height: 100vh;
  overflow: hidden;
}

/* ── Sidebar ───────────────────────────── */
.sidebar {
  width: var(--sidebar-width);
  min-width: var(--sidebar-width);
  background: var(--bg-sidebar);
  color: var(--text-inverse);
  display: flex;
  flex-direction: column;
  overflow-y: auto;
  overflow-x: hidden;
  transition: width var(--transition-normal);
  z-index: 100;
}

.sidebar-header {
  padding: var(--space-lg) var(--space-lg);
  border-bottom: 1px solid rgba(255, 255, 255, 0.08);
}

.sidebar-logo {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
}

.logo-icon {
  width: 32px;
  height: 32px;
  border-radius: var(--radius-md);
  background: var(--brand-primary);
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  font-size: 13px;
  flex-shrink: 0;
}

.logo-text {
  font-weight: 600;
  font-size: 15px;
  line-height: 1.3;
  opacity: 0.95;
}

/* Nav */
.nav {
  flex: 1;
  padding: var(--space-sm) 0;
  list-style: none;
}

.nav-section {
  padding: var(--space-sm) var(--space-lg) var(--space-xs);
  font-size: 11px;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: rgba(255, 255, 255, 0.4);
}

/* ── Collapsible Nav Group ─────────────────── */
.nav-group {
  margin-bottom: 2px;
}
.nav-group-header {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  padding: var(--space-sm) var(--space-lg);
  color: rgba(255, 255, 255, 0.7);
  cursor: pointer;
  border: none;
  background: none;
  width: 100%;
  text-align: left;
  font-size: 13px;
  font-weight: 600;
  transition: all var(--transition-fast);
  position: relative;
}
.nav-group-header:hover {
  color: var(--text-inverse);
  background: rgba(255, 255, 255, 0.06);
}
.nav-group-header .nav-group-icon {
  width: 18px;
  height: 18px;
  flex-shrink: 0;
}
.nav-group-header .nav-group-label {
  flex: 1;
}
.nav-group-header .nav-group-zh {
  font-size: 11px;
  color: rgba(255, 255, 255, 0.35);
  font-weight: 400;
  margin-left: auto;
}
.nav-group-header .nav-chevron {
  width: 14px;
  height: 14px;
  flex-shrink: 0;
  transition: transform var(--transition-fast);
  opacity: 0.5;
}
.nav-group.expanded .nav-chevron {
  transform: rotate(90deg);
}
.nav-group.expanded .nav-group-header {
  color: var(--text-inverse);
}
.nav-children {
  display: none;
  overflow: hidden;
}
.nav-group.expanded .nav-children {
  display: block;
}

.nav-item {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  padding: var(--space-xs) var(--space-lg) var(--space-xs) calc(var(--space-lg) + 24px);
  color: rgba(255, 255, 255, 0.6);
  cursor: pointer;
  border: none;
  background: none;
  width: 100%;
  text-align: left;
  font-size: 13px;
  font-weight: 500;
  transition: all var(--transition-fast);
  position: relative;
}

.nav-item:hover {
  color: var(--text-inverse);
  background: rgba(255, 255, 255, 0.06);
}

.nav-item.active {
  color: var(--text-inverse);
  background: rgba(255, 255, 255, 0.1);
}

.nav-item.active::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0;
  bottom: 0;
  width: 3px;
  background: var(--brand-primary);
  border-radius: 0 2px 2px 0;
}

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

.nav-label-en {
  font-size: 11px;
  color: rgba(255, 255, 255, 0.35);
  font-weight: 400;
  margin-left: auto;
  letter-spacing: 0.02em;
}

/* Sidebar Footer */
.sidebar-footer {
  padding: var(--space-md) var(--space-lg);
  border-top: 1px solid rgba(255, 255, 255, 0.08);
  font-size: 12px;
  color: rgba(255, 255, 255, 0.5);
}

.user-row {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  margin-bottom: var(--space-xs);
}

.username { color: rgba(255, 255, 255, 0.8); font-weight: 500; }
.btn-logout {
  background: none;
  border: 1px solid rgba(255, 255, 255, 0.2);
  color: rgba(255, 255, 255, 0.6);
  padding: 2px 8px;
  border-radius: var(--radius-sm);
  font-size: 11px;
  cursor: pointer;
  transition: all var(--transition-fast);
}
.btn-logout:hover {
  color: var(--text-inverse);
  border-color: rgba(255, 255, 255, 0.4);
}

/* ── Main Content ──────────────────────── */
.main {
  flex: 1;
  display: flex;
  flex-direction: column;
  overflow: hidden;
}

.topbar {
  height: var(--topbar-height);
  background: var(--bg-primary);
  border-bottom: 1px solid var(--border-color);
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 var(--space-xl);
  flex-shrink: 0;
}

.topbar h2 {
  font-size: 18px;
  font-weight: 600;
}

.content {
  flex: 1;
  overflow-y: auto;
  padding: var(--space-xl);
  background: var(--bg-secondary);
}

/* ── Page Container ────────────────────── */
.page { display: none; }
.page.active { display: block; }

/* ── Login Overlay ─────────────────────── */
.login-overlay {
  position: fixed;
  inset: 0;
  background: var(--bg-sidebar);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 1000;
}

.login-overlay.hidden { display: none; }

.login-box {
  background: var(--bg-primary);
  border-radius: var(--radius-lg);
  padding: var(--space-3xl);
  width: 380px;
  box-shadow: var(--shadow-xl);
}

.login-box h2 {
  text-align: center;
  margin-bottom: var(--space-xl);
  font-size: 20px;
}

.form-group {
  margin-bottom: var(--space-lg);
}

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

.form-input, .form-select, .form-textarea {
  width: 100%;
  padding: var(--space-sm) var(--space-md);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  font-size: 14px;
  font-family: inherit;
  transition: border-color var(--transition-fast);
  background: var(--bg-primary);
}

.form-input:focus, .form-select:focus, .form-textarea:focus {
  outline: none;
  border-color: var(--brand-primary);
  box-shadow: 0 0 0 3px var(--brand-primary-light);
}

.form-textarea { resize: vertical; min-height: 80px; }
.form-check { display: flex; align-items: center; gap: var(--space-sm); }

/* ── Utility ───────────────────────────── */
.hidden { display: none !important; }
.mt-4 { margin-top: var(--space-md); }
.mt-8 { margin-top: var(--space-lg); }
.mb-4 { margin-bottom: var(--space-md); }
.mb-8 { margin-bottom: var(--space-lg); }
.text-sm { font-size: 13px; }
.text-muted { color: var(--text-tertiary); }
.text-danger { color: var(--brand-danger); }
.text-success { color: var(--brand-success); }
.font-mono { font-family: var(--font-mono); font-size: 12px; }