/* ==========================================================================
   LAYOUT — Header, Footer, Container, Grid
   ========================================================================== */

/* ---------- SITE HEADER ---------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: var(--bg);
  border-bottom: 1px solid var(--border);
  transition: box-shadow var(--transition);
}

.site-header.scrolled {
  box-shadow: var(--shadow);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-md);
  height: var(--header-height);
}

/* ---------- LOGO ---------- */
.logo {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  font-size: var(--fs-base);
  font-weight: var(--fw-bold);
  color: var(--text);
  white-space: nowrap;
}

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

.logo svg {
  width: 20px;
  height: 20px;
  color: var(--primary);
  flex-shrink: 0;
}

/* ---------- NAV DESKTOP ---------- */
.nav-desktop {
  display: none;
  align-items: center;
  gap: var(--space-lg);
  margin-left: auto;
}

.nav-desktop a {
  font-size: var(--fs-sm);
  color: var(--text-muted);
  transition: color var(--transition);
}

.nav-desktop a:hover {
  color: var(--primary);
  text-decoration: none;
}

.nav-desktop a.active {
  color: var(--text);
  font-weight: var(--fw-medium);
}

/* ---------- HEADER ACTIONS ---------- */
.header-actions {
  display: flex;
  align-items: center;
  gap: var(--space-xs);
}

.icon-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 40px;
  height: 40px;
  border-radius: var(--radius-sm);
  color: var(--text-muted);
  transition: background var(--transition), color var(--transition);
}

.icon-btn:hover {
  background: var(--surface);
  color: var(--text);
}

.icon-btn svg {
  width: 20px;
  height: 20px;
}

/* ---------- LANGUAGE SWITCHER ---------- */
.lang-switch {
  position: relative;
}

.lang-toggle {
  display: inline-flex;
  align-items: center;
  gap: 4px;
  padding: 6px 10px;
  font-size: var(--fs-sm);
  font-weight: var(--fw-medium);
  color: var(--text);
  background: var(--surface);
  border-radius: var(--radius-sm);
  transition: background var(--transition), color var(--transition);
}

.lang-toggle:hover {
  background: var(--border);
}

.lang-toggle svg {
  width: 16px;
  height: 16px;
  flex-shrink: 0;
}

.lang-toggle .lang-current {
  font-weight: var(--fw-bold);
  color: var(--primary);
}

.lang-toggle .lang-chevron {
  width: 14px;
  height: 14px;
  color: var(--text-muted);
  transition: transform var(--transition);
}

.lang-switch.open .lang-toggle .lang-chevron {
  transform: rotate(180deg);
}

.lang-menu {
  position: absolute;
  top: calc(100% + 6px);
  right: 0;
  z-index: 200;
  min-width: 180px;
  padding: 4px;
  margin: 0;
  list-style: none;
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.12);
  opacity: 0;
  visibility: hidden;
  transform: translateY(-4px);
  transition: opacity var(--transition), visibility var(--transition), transform var(--transition);
}

.lang-switch.open .lang-menu {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
}

.lang-menu li {
  list-style: none;
  margin: 0;
}

.lang-menu button {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  width: 100%;
  padding: 8px 10px;
  font-size: var(--fs-sm);
  color: var(--text);
  background: transparent;
  border-radius: var(--radius-sm);
  text-align: left;
  transition: background var(--transition), color var(--transition);
}

.lang-menu button:hover {
  background: var(--surface);
}

.lang-menu button .lang-code {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 28px;
  height: 20px;
  font-size: 11px;
  font-weight: var(--fw-bold);
  font-family: var(--font-mono);
  color: var(--text-muted);
  background: var(--surface);
  border-radius: 3px;
  flex-shrink: 0;
}

.lang-menu button .lang-name {
  flex: 1;
  color: var(--text-muted);
}

.lang-menu button.active {
  color: var(--primary);
}

.lang-menu button.active .lang-code {
  background: var(--primary);
  color: #FFFFFF;
}

.lang-menu button.active .lang-name {
  color: var(--primary);
  font-weight: var(--fw-medium);
}

[data-theme="dark"] .lang-menu {
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.5);
}

/* ---------- MOBILE MENU ---------- */
.mobile-menu {
  position: fixed;
  inset: 0;
  z-index: 200;
  display: none;
}

.mobile-menu.open {
  display: block;
}

.mobile-menu-overlay {
  position: absolute;
  inset: 0;
  background: rgba(0, 0, 0, 0.4);
}

.mobile-menu-drawer {
  position: absolute;
  top: 0;
  left: 0;
  bottom: 0;
  width: min(320px, 85vw);
  background: var(--bg);
  padding: var(--space-lg);
  overflow-y: auto;
  display: flex;
  flex-direction: column;
  gap: var(--space-lg);
}

.mobile-menu-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding-bottom: var(--space-md);
  border-bottom: 1px solid var(--border);
}

.mobile-menu-nav {
  display: flex;
  flex-direction: column;
  gap: var(--space-xs);
}

.mobile-menu-nav a {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  padding: var(--space-sm) var(--space-md);
  font-size: var(--fs-base);
  color: var(--text);
  border-radius: var(--radius-sm);
  transition: background var(--transition);
}

.mobile-menu-nav a:hover {
  background: var(--surface);
  text-decoration: none;
}

.mobile-menu-nav svg {
  width: 20px;
  height: 20px;
  color: var(--text-muted);
  flex-shrink: 0;
}

/* ---------- MAIN ---------- */
main {
  min-height: calc(100vh - var(--header-height) - 200px);
}

/* ---------- SECTIONS ---------- */
.section {
  padding: var(--space-2xl) 0;
  border-bottom: 1px solid var(--border);
}

.section:last-of-type {
  border-bottom: none;
}

.section-header {
  margin-bottom: var(--space-lg);
}

.section-header h2 {
  margin-bottom: var(--space-xs);
}

.section-header p {
  color: var(--text-muted);
  font-size: var(--fs-base);
  margin-bottom: 0;
}

/* ---------- HERO ---------- */
.hero {
  padding: var(--space-2xl) 0;
  border-bottom: 1px solid var(--border);
}

.hero-inner {
  max-width: 640px;
}

.hero-label {
  display: inline-block;
  font-size: var(--fs-sm);
  font-weight: var(--fw-medium);
  color: var(--primary);
  margin-bottom: var(--space-sm);
}

.hero h1 {
  font-size: clamp(1.75rem, 5vw, 2.5rem);
  margin-bottom: var(--space-md);
}

.hero p {
  font-size: var(--fs-lg);
  color: var(--text-muted);
  margin-bottom: var(--space-lg);
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-sm);
}

/* ---------- GRID SYSTEMS ---------- */
.grid-2 {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-md);
}

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

.grid-4 {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-md);
}

/* ---------- SITE FOOTER ---------- */
.site-footer {
  padding: var(--space-xl) 0;
  background: var(--surface);
  font-size: var(--fs-sm);
  color: var(--text-muted);
}

.footer-inner {
  display: flex;
  flex-direction: column;
  gap: var(--space-md);
}

.footer-disclaimer {
  padding: var(--space-md);
  background: var(--bg);
  border-radius: var(--radius-md);
  font-size: var(--fs-sm);
  color: var(--text-muted);
  line-height: 1.6;
}

.footer-disclaimer strong {
  color: var(--text);
  font-weight: var(--fw-medium);
}

.footer-bottom {
  display: flex;
  flex-direction: column;
  gap: var(--space-sm);
  font-size: var(--fs-sm);
  color: var(--text-muted);
}

/* ---------- RESPONSIVE ---------- */
@media (min-width: 640px) {
  :root {
    --header-height: 64px;
  }

  .nav-desktop {
    display: flex;
  }

  .menu-toggle {
    display: none;
  }

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

  .footer-bottom {
    flex-direction: row;
    justify-content: space-between;
    align-items: center;
  }
}

@media (min-width: 1024px) {
  .grid-3 { grid-template-columns: repeat(3, 1fr); }
  .grid-4 { grid-template-columns: repeat(4, 1fr); }

  .hero {
    padding: 64px 0;
  }

  .section {
    padding: 64px 0;
  }
}