/* ========================================
   Common Styles
   ======================================== */

body {
  font-family: var(--font-sans);
  background-color: var(--color-bg);
  color: var(--color-text);
}

.container {
  width: 100%;
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 var(--space-md);
}

/* ----------------------------------------
   Header
   ---------------------------------------- */

.site-header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 100;
  padding: var(--space-md) var(--space-lg);
  display: flex;
  align-items: center;
  justify-content: space-between;
  transition: background-color var(--transition-base), box-shadow var(--transition-base), padding var(--transition-base);
}

.site-header.scrolled {
  background-color: rgba(255, 255, 255, 0.95);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  box-shadow: var(--shadow-sm);
  padding: var(--space-sm) var(--space-lg);
}

.logo {
  font-family: var(--font-serif);
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--color-text);
  transition: color var(--transition-fast);
}

.logo:hover {
  color: var(--color-eng-primary);
}

.header-nav {
  display: flex;
  align-items: center;
  gap: var(--space-lg);
}

.header-nav a {
  font-size: 0.9375rem;
  font-weight: 500;
  color: var(--color-text-muted);
  transition: color var(--transition-fast);
  position: relative;
}

.header-nav a::after {
  content: '';
  position: absolute;
  bottom: -4px;
  left: 0;
  width: 0;
  height: 2px;
  background: var(--color-eng-gradient);
  transition: width var(--transition-base);
}

.header-nav a:hover {
  color: var(--color-text);
}

.header-nav a:hover::after {
  width: 100%;
}

/* Language toggle */

.lang-toggle {
  display: inline-flex;
  background: var(--color-bg-alt);
  border-radius: var(--radius-full);
  padding: 0.1875rem;
  border: 1px solid var(--color-border);
  cursor: pointer;
}

.lang-toggle:focus-visible {
  outline: 2px solid var(--color-eng-primary);
  outline-offset: 2px;
}

.lang-option {
  padding: 0.3125rem 0.625rem;
  border-radius: var(--radius-full);
  font-size: 0.8125rem;
  font-weight: 600;
  color: var(--color-text-muted);
  transition: all var(--transition-fast);
  border: none;
  background: transparent;
  cursor: pointer;
  line-height: 1;
}

.lang-option.active {
  background: var(--color-text);
  color: var(--color-surface);
}

/* Hamburger menu (mobile) */

.hamburger {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
  padding: var(--space-xs);
}

.hamburger span {
  display: block;
  width: 24px;
  height: 2px;
  background: var(--color-text);
  transition: all var(--transition-base);
}

.hamburger.active span:nth-child(1) {
  transform: rotate(45deg) translate(5px, 5px);
}

.hamburger.active span:nth-child(2) {
  opacity: 0;
}

.hamburger.active span:nth-child(3) {
  transform: rotate(-45deg) translate(5px, -5px);
}

@media (max-width: 768px) {
  .hamburger {
    display: flex;
  }

  .header-nav {
    position: fixed;
    top: 0;
    right: -100%;
    width: 280px;
    height: 100vh;
    background: var(--color-surface);
    flex-direction: column;
    justify-content: center;
    gap: var(--space-xl);
    box-shadow: var(--shadow-lg);
    transition: right var(--transition-base);
    z-index: 99;
  }

  .header-nav.open {
    right: 0;
  }

  .header-nav a {
    font-size: 1.25rem;
  }
}

/* ----------------------------------------
   Sections
   ---------------------------------------- */

.section {
  padding: var(--space-2xl) 0;
}

.section-title {
  font-family: var(--font-serif);
  font-size: 2rem;
  font-weight: 700;
  margin-bottom: var(--space-xl);
  text-align: center;
}

.section-subtitle {
  font-size: 1.125rem;
  color: var(--color-text-muted);
  text-align: center;
  margin-top: calc(-1 * var(--space-lg));
  margin-bottom: var(--space-xl);
}

/* ----------------------------------------
   Footer
   ---------------------------------------- */

.site-footer {
  padding: var(--space-xl) 0;
  text-align: center;
  color: var(--color-text-muted);
  font-size: 0.875rem;
  border-top: 1px solid var(--color-border);
}

.site-footer a {
  color: var(--color-eng-primary);
  transition: color var(--transition-fast);
}

.site-footer a:hover {
  color: var(--color-eng-secondary);
}

/* ----------------------------------------
   Scroll Animation
   ---------------------------------------- */

.animate-on-scroll {
  opacity: 0;
  transform: translateY(20px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}

.animate-on-scroll.is-visible {
  opacity: 1;
  transform: translateY(0);
}

@media (prefers-reduced-motion: reduce) {
  .animate-on-scroll {
    opacity: 1;
    transform: none;
    transition: none;
  }
}

/* ----------------------------------------
   Link Cards (shared)
   ---------------------------------------- */

.links-grid {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: var(--space-md);
}

.link-card {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  padding: var(--space-md) var(--space-lg);
  background: var(--color-surface);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-sm);
  font-weight: 500;
  transition: transform var(--transition-fast), box-shadow var(--transition-fast);
}

.link-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-md);
}

.link-card svg {
  width: 24px;
  height: 24px;
  flex-shrink: 0;
}

/* ----------------------------------------
   Utility
   ---------------------------------------- */

.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  border: 0;
}