/* layout.css - Navigation, Footer, Grid System for AI Ethics Registry */

/* ========================================
   CONTAINER
   ======================================== */

.container {
  width: 100%;
  max-width: 80rem;
  margin: 0 auto;
  padding: 0 var(--spacing-4);
}

@media (min-width: 640px) {
  .container { padding: 0 var(--spacing-6); }
}

@media (min-width: 1024px) {
  .container { padding: 0 var(--spacing-8); }
}

/* ========================================
   NAVIGATION
   ======================================== */

.nav {
  position: sticky;
  top: 0;
  z-index: var(--z-fixed);
  background: var(--color-white);
  border-bottom: 1px solid var(--color-border);
}

.nav-inner {
  display: flex;
  justify-content: space-between;
  align-items: center;
  height: 64px;
  max-width: 80rem;
  margin: 0 auto;
  padding: 0 var(--spacing-4);
}

@media (min-width: 640px) {
  .nav-inner { padding: 0 var(--spacing-6); }
}

@media (min-width: 1024px) {
  .nav-inner { padding: 0 var(--spacing-8); }
}

.nav-logo {
  display: flex;
  align-items: center;
  gap: var(--spacing-3);
}

.nav-logo-icon {
  width: 32px;
  height: 32px;
  background: var(--color-slate-900);
  border-radius: var(--radius-sm);
  display: flex;
  align-items: center;
  justify-content: center;
  color: white;
  font-family: var(--font-serif);
  font-weight: var(--font-bold);
  font-size: var(--text-sm);
}

.nav-logo-text {
  font-weight: var(--font-semibold);
  font-size: var(--text-base);
  color: var(--color-text-primary);
}

.nav-logo-text .accent {
  color: var(--color-accent);
}

.nav-links {
  display: none;
  gap: var(--spacing-6);
}

@media (min-width: 768px) {
  .nav-links { display: flex; }
}

.nav-link {
  font-size: var(--text-sm);
  font-weight: var(--font-medium);
  color: var(--color-text-muted);
  transition: color var(--transition-base);
}

.nav-link:hover,
.nav-link.active {
  color: var(--color-text-primary);
}

.nav-actions {
  display: flex;
  align-items: center;
  gap: var(--spacing-4);
}

.nav-mobile-toggle {
  display: flex;
  padding: var(--spacing-2);
  background: transparent;
  border: none;
  color: var(--color-text-secondary);
  cursor: pointer;
}

@media (min-width: 768px) {
  .nav-mobile-toggle { display: none; }
}

.nav-mobile-toggle svg {
  width: 24px;
  height: 24px;
}

.nav-mobile {
  display: none;
  position: fixed;
  top: 64px;
  left: 0;
  right: 0;
  background: var(--color-white);
  border-bottom: 1px solid var(--color-border);
  padding: var(--spacing-4);
  z-index: var(--z-fixed);
}

.nav-mobile.active {
  display: block;
}

.nav-mobile .nav-link {
  display: block;
  padding: var(--spacing-3) 0;
  font-size: var(--text-base);
  border-bottom: 1px solid var(--color-border);
}

/* ========================================
   PAGE LAYOUTS
   ======================================== */

.page {
  min-height: 100vh;
}

.page-header {
  padding: var(--spacing-12) 0;
  border-bottom: 1px solid var(--color-border);
  background: var(--color-white);
}

.page-header h1 {
  margin-bottom: var(--spacing-4);
}

.page-header p {
  max-width: 36rem;
}

.page-content {
  padding: var(--spacing-12) 0;
}

/* ========================================
   HERO SECTION
   ======================================== */

.hero {
  padding: var(--spacing-16) 0;
  background: var(--color-white);
  border-bottom: 1px solid var(--color-border);
}

@media (min-width: 1024px) {
  .hero { padding: var(--spacing-24) 0; }
}

.hero-content {
  max-width: 48rem;
}

.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: var(--spacing-2);
  padding: var(--spacing-1) var(--spacing-3);
  border-radius: var(--radius-full);
  background: var(--color-slate-100);
  color: var(--color-slate-600);
  font-size: var(--text-xs);
  font-weight: var(--font-semibold);
  text-transform: uppercase;
  letter-spacing: 0.05em;
  margin-bottom: var(--spacing-6);
}

.hero-title {
  font-size: clamp(2rem, 5vw, 3.5rem);
  font-weight: var(--font-bold);
  line-height: 1.1;
  margin-bottom: var(--spacing-6);
  font-family: var(--font-serif);
}

.hero-subtitle {
  font-size: var(--text-xl);
  color: var(--color-text-muted);
  line-height: 1.6;
  margin-bottom: var(--spacing-8);
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: var(--spacing-4);
}

/* ========================================
   SECTIONS
   ======================================== */

.section {
  padding: var(--spacing-16) 0;
}

.section-alt {
  background: var(--color-white);
  border-top: 1px solid var(--color-border);
  border-bottom: 1px solid var(--color-border);
}

.section-header {
  margin-bottom: var(--spacing-12);
}

.section-header h2 {
  margin-bottom: var(--spacing-4);
}

.section-header-flex {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-4);
  margin-bottom: var(--spacing-8);
}

@media (min-width: 768px) {
  .section-header-flex {
    flex-direction: row;
    justify-content: space-between;
    align-items: center;
  }
}

/* ========================================
   GRID SYSTEM
   ======================================== */

.grid-2 {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--spacing-6);
}

@media (min-width: 768px) {
  .grid-2 { grid-template-columns: repeat(2, 1fr); }
}

.grid-3 {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--spacing-6);
}

@media (min-width: 768px) {
  .grid-3 { grid-template-columns: repeat(2, 1fr); }
}

@media (min-width: 1024px) {
  .grid-3 { grid-template-columns: repeat(3, 1fr); }
}

.grid-4 {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: var(--spacing-4);
}

@media (min-width: 768px) {
  .grid-4 { grid-template-columns: repeat(4, 1fr); }
}

/* ========================================
   SIDEBAR LAYOUT
   ======================================== */

.layout-sidebar {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--spacing-8);
}

@media (min-width: 1024px) {
  .layout-sidebar {
    grid-template-columns: 280px 1fr;
  }
}

.sidebar {
  position: sticky;
  top: 80px;
  height: fit-content;
}

.sidebar-nav {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-1);
}

.sidebar-link {
  padding: var(--spacing-3) var(--spacing-4);
  font-size: var(--text-sm);
  color: var(--color-text-muted);
  border-radius: var(--radius-md);
  transition: all var(--transition-base);
}

.sidebar-link:hover {
  color: var(--color-text-secondary);
  background: var(--color-slate-100);
}

.sidebar-link.active {
  color: var(--color-text-primary);
  background: var(--color-slate-100);
}

/* ========================================
   FOOTER
   ======================================== */

.footer {
  padding: var(--spacing-12) 0 var(--spacing-8);
  border-top: 1px solid var(--color-border);
  background: var(--color-white);
}

.footer-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--spacing-8);
  margin-bottom: var(--spacing-8);
}

@media (min-width: 768px) {
  .footer-grid {
    grid-template-columns: 2fr repeat(3, 1fr);
  }
}

.footer-brand {
  max-width: 280px;
}

.footer-brand .nav-logo {
  margin-bottom: var(--spacing-4);
}

.footer-brand p {
  font-size: var(--text-sm);
}

.footer-heading {
  font-size: var(--text-sm);
  font-weight: var(--font-semibold);
  color: var(--color-text-primary);
  margin-bottom: var(--spacing-4);
}

.footer-links {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-3);
}

.footer-link {
  font-size: var(--text-sm);
  color: var(--color-text-muted);
  transition: color var(--transition-base);
}

.footer-link:hover {
  color: var(--color-text-primary);
}

.footer-bottom {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-4);
  padding-top: var(--spacing-8);
  border-top: 1px solid var(--color-border);
}

@media (min-width: 768px) {
  .footer-bottom {
    flex-direction: row;
    justify-content: space-between;
    align-items: center;
  }
}

.footer-copyright {
  font-size: var(--text-sm);
  color: var(--color-text-muted);
}

/* ========================================
   LEDGER-SPECIFIC STYLES
   ======================================== */

.ledger-entry {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--spacing-4);
  padding: var(--spacing-6);
  border-bottom: 1px solid var(--color-border);
}

@media (min-width: 768px) {
  .ledger-entry {
    grid-template-columns: 2fr 1fr 1fr auto;
    align-items: center;
  }
}

.ledger-entry:last-child {
  border-bottom: none;
}

.ledger-entry:hover {
  background: var(--color-slate-50);
}

.ledger-id {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  color: var(--color-text-muted);
}

/* ========================================
   TABS
   ======================================== */

.tabs {
  display: flex;
  gap: var(--spacing-1);
  border-bottom: 1px solid var(--color-border);
  margin-bottom: var(--spacing-8);
  overflow-x: auto;
}

.tab {
  padding: var(--spacing-3) var(--spacing-4);
  font-size: var(--text-sm);
  font-weight: var(--font-medium);
  color: var(--color-text-muted);
  background: transparent;
  border: none;
  border-bottom: 2px solid transparent;
  cursor: pointer;
  transition: all var(--transition-base);
  white-space: nowrap;
}

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

.tab.active {
  color: var(--color-text-primary);
  border-bottom-color: var(--color-slate-900);
}

.tab-panel {
  display: none;
}

.tab-panel.active {
  display: block;
  animation: fadeIn 0.3s ease;
}

/* ========================================
   PAGINATION
   ======================================== */

.pagination {
  display: flex;
  justify-content: center;
  gap: var(--spacing-2);
  margin-top: var(--spacing-12);
}

.pagination-btn {
  width: 40px;
  height: 40px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: var(--text-sm);
  color: var(--color-text-muted);
  background: var(--color-white);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  cursor: pointer;
  transition: all var(--transition-base);
}

.pagination-btn:hover:not(:disabled) {
  color: var(--color-text-primary);
  border-color: var(--color-slate-300);
}

.pagination-btn.active {
  color: white;
  background: var(--color-slate-900);
  border-color: var(--color-slate-900);
}