/* ============================================================
   CHINA COMPASS — Layout
   Container · Grid · Navigation · Footer · Responsive
   ============================================================ */

/* ---------- Container ---------- */
.container {
  width: 100%;
  max-width: var(--container-xl);
  margin: 0 auto;
  padding: 0 var(--space-5);
}

.container-narrow {
  max-width: var(--container-lg);
}

.container-wide {
  max-width: var(--container-2xl);
}

/* ---------- Grid System ---------- */
.grid {
  display: grid;
  gap: var(--space-5);
}

.grid-2 { grid-template-columns: repeat(2, 1fr); }
.grid-3 { grid-template-columns: repeat(3, 1fr); }
.grid-4 { grid-template-columns: repeat(4, 1fr); }

.grid-sidebar {
  grid-template-columns: 1fr 320px;
  gap: var(--space-8);
}

.grid-sidebar-left {
  grid-template-columns: 260px 1fr;
  gap: var(--space-8);
}

/* ---------- Flex Utilities ---------- */
.flex {
  display: flex;
}

.flex-col {
  flex-direction: column;
}

.flex-wrap {
  flex-wrap: wrap;
}

.items-center {
  align-items: center;
}

.justify-between {
  justify-content: space-between;
}

.gap-2 { gap: var(--space-2); }
.gap-3 { gap: var(--space-3); }
.gap-4 { gap: var(--space-4); }
.gap-5 { gap: var(--space-5); }
.gap-6 { gap: var(--space-6); }

/* ---------- Section Spacing ---------- */
.section {
  padding: var(--space-10) 0;
}

.section + .section {
  border-top: 1px solid var(--border-light);
}

/* ---------- Navigation ---------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: var(--nav-bg);
  border-bottom: 1px solid var(--nav-border);
  transition: background-color var(--transition-normal);
}

.site-header__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 56px;
  max-width: var(--container-xl);
  margin: 0 auto;
  padding: 0 var(--space-5);
}

.site-logo {
  font-size: var(--text-lg);
  font-weight: var(--weight-bold);
  color: var(--text-primary);
  text-decoration: none;
  white-space: nowrap;
  display: flex;
  align-items: center;
  gap: var(--space-2);
}

.site-logo:hover {
  text-decoration: none;
  color: var(--accent);
}

.site-logo__mark {
  color: var(--accent);
}

/* Main nav */
.main-nav {
  display: flex;
  align-items: center;
  gap: var(--space-1);
}

.main-nav__link {
  padding: var(--space-2) var(--space-3);
  font-size: var(--text-sm);
  font-weight: var(--weight-medium);
  color: var(--text-secondary);
  text-decoration: none;
  border-radius: var(--radius-sm);
  transition: color var(--transition-fast), background var(--transition-fast);
  white-space: nowrap;
}

.main-nav__link:hover {
  color: var(--text-primary);
  background: var(--bg-secondary);
  text-decoration: none;
}

.main-nav__link[aria-current="page"],
.main-nav__link.active {
  color: var(--accent);
  font-weight: var(--weight-semibold);
}

/* Header actions (lang + theme toggle) */
.header-actions {
  display: flex;
  align-items: center;
  gap: var(--space-3);
}

.lang-toggle {
  font-size: var(--text-sm);
  font-weight: var(--weight-medium);
  color: var(--text-muted);
  text-decoration: none;
  padding: var(--space-1) var(--space-2);
  border: 1px solid var(--border-medium);
  border-radius: var(--radius-sm);
  transition: all var(--transition-fast);
}

.lang-toggle:hover {
  color: var(--accent);
  border-color: var(--accent);
  text-decoration: none;
}

.theme-toggle {
  background: none;
  border: 1px solid var(--border-medium);
  border-radius: var(--radius-sm);
  padding: var(--space-1) var(--space-2);
  cursor: pointer;
  color: var(--text-muted);
  font-size: var(--text-lg);
  display: flex;
  align-items: center;
  justify-content: center;
  width: 34px;
  height: 34px;
  transition: all var(--transition-fast);
}

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

/* Sun/moon icons via CSS */
.theme-toggle .icon-sun,
.theme-toggle .icon-moon {
  display: none;
}

[data-theme="light"] .theme-toggle .icon-sun { display: block; }
[data-theme="light"] .theme-toggle .icon-moon { display: none; }
[data-theme="dark"] .theme-toggle .icon-sun { display: none; }
[data-theme="dark"] .theme-toggle .icon-moon { display: block; }

/* ---------- Mobile Hamburger (CSS-only, checkbox hack) ---------- */
.hamburger-toggle {
  display: none;
}

.hamburger-label {
  display: none;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  width: 34px;
  height: 34px;
  cursor: pointer;
  border: 1px solid var(--border-medium);
  border-radius: var(--radius-sm);
}

.hamburger-label span,
.hamburger-label span::before,
.hamburger-label span::after {
  display: block;
  width: 18px;
  height: 2px;
  background: var(--text-secondary);
  position: relative;
  transition: all var(--transition-fast);
}

.hamburger-label span::before,
.hamburger-label span::after {
  content: '';
  position: absolute;
}

.hamburger-label span::before { top: -6px; }
.hamburger-label span::after  { top: 6px; }

.hamburger-toggle:checked + .hamburger-label span {
  background: transparent;
}

.hamburger-toggle:checked + .hamburger-label span::before {
  top: 0;
  transform: rotate(45deg);
}

.hamburger-toggle:checked + .hamburger-label span::after {
  top: 0;
  transform: rotate(-45deg);
}

/* ---------- Footer ---------- */
.site-footer {
  background: var(--bg-secondary);
  border-top: 1px solid var(--border-light);
  padding: var(--space-8) 0;
  margin-top: var(--space-12);
}

.site-footer__inner {
  max-width: var(--container-xl);
  margin: 0 auto;
  padding: 0 var(--space-5);
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  flex-wrap: wrap;
  gap: var(--space-8);
}

.footer-section {
  flex: 1;
  min-width: 180px;
}

.footer-section__title {
  font-size: var(--text-sm);
  font-weight: var(--weight-bold);
  color: var(--text-primary);
  text-transform: uppercase;
  letter-spacing: 0.05em;
  margin-bottom: var(--space-3);
}

.footer-section__list {
  list-style: none;
  padding: 0;
  margin: 0;
}

.footer-section__list li {
  margin-bottom: var(--space-2);
}

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

.footer-section__list a:hover {
  color: var(--accent);
}

.footer-powered {
  width: 100%;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-3);
  padding-top: var(--space-5);
  margin-top: var(--space-5);
  border-top: 1px solid var(--border-light);
}

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

.footer-powered__logo {
  height: 48px;
  width: auto;
}

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

.site-footer__bottom {
  width: 100%;
  padding-top: var(--space-3);
  text-align: center;
  font-size: var(--text-sm);
  color: var(--text-muted);
}

/* ---------- Main Content Area ---------- */
.main-content {
  min-height: calc(100vh - 56px - 200px);
}

/* ---------- Responsive Breakpoints ---------- */

/* Tablet: 768px and below */
@media (max-width: 768px) {
  .container {
    padding: 0 var(--space-4);
  }

  .grid-2 { grid-template-columns: 1fr; }
  .grid-3 { grid-template-columns: 1fr; }
  .grid-4 { grid-template-columns: repeat(2, 1fr); }
  .grid-sidebar { grid-template-columns: 1fr; }
  .grid-sidebar-left { grid-template-columns: 1fr; }

  h1 { font-size: var(--text-3xl); }
  h2 { font-size: var(--text-2xl); }
  h3 { font-size: var(--text-xl); }

  .section {
    padding: var(--space-6) 0;
  }

  /* Show hamburger, hide nav */
  .hamburger-label {
    display: flex;
  }

  .main-nav {
    display: none;
    position: absolute;
    top: 56px;
    left: 0;
    right: 0;
    background: var(--nav-bg);
    border-bottom: 1px solid var(--nav-border);
    flex-direction: column;
    padding: var(--space-4);
    box-shadow: var(--shadow-lg);
    z-index: 99;
  }

  .hamburger-toggle:checked ~ .main-nav {
    display: flex;
  }

  .main-nav__link {
    padding: var(--space-3) var(--space-4);
    width: 100%;
  }

  .hero-strip {
    padding: var(--space-6) 0;
  }

  .hero-strip__title {
    font-size: var(--text-2xl);
  }

  .site-footer__inner {
    flex-direction: column;
    gap: var(--space-5);
  }

  .footer-section {
    min-width: 0;
    width: 100%;
  }

  /* Standalone grid classes (used without .grid parent) */
  .grid-2,
  .grid-3,
  .grid-4 {
    display: grid;
  }

  .main-nav {
    max-height: calc(100vh - 56px);
    overflow-y: auto;
  }

  .main-nav__link {
    min-height: 44px;
    display: flex;
    align-items: center;
  }

  .grid {
    gap: var(--space-4);
  }

  .site-footer__inner {
    gap: var(--space-4);
  }

  .container-narrow {
    padding: 0 var(--space-4);
  }
}

/* Small mobile: 375px and below */
@media (max-width: 480px) {
  .grid-4 { grid-template-columns: 1fr; }

  .container {
    padding: 0 var(--space-4);
  }

  h1 { font-size: var(--text-2xl); }

  .stat-card__value {
    font-size: var(--text-2xl);
  }

  .tension-display__score {
    font-size: 3rem;
  }

  .site-header__inner {
    height: 48px;
  }

  .grid {
    gap: var(--space-3);
  }

  .section {
    padding: var(--space-4) 0;
  }

  .site-footer {
    padding: var(--space-5) 0;
    margin-top: var(--space-8);
  }

  .main-nav {
    max-height: calc(100vh - 48px);
    top: 48px;
  }
}

/* Desktop: 1024px+ tweaks */
@media (min-width: 1024px) {
  .grid-3-tablet {
    grid-template-columns: repeat(3, 1fr);
  }
}

/* Large desktop: 1440px+ */
@media (min-width: 1440px) {
  .container {
    padding: 0 var(--space-8);
  }
}

/* ---------- Print ---------- */
@media print {
  .site-header,
  .site-footer,
  .theme-toggle,
  .lang-toggle,
  .hamburger-label,
  .filter-bar {
    display: none !important;
  }

  body {
    background: white;
    color: black;
  }

  .card, .signal-card, .stat-card {
    box-shadow: none;
    border: 1px solid #ccc;
  }
}