/* ===== Global Styles ===== */

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

.container {
  max-width: var(--container-max);
  margin: 0 auto;
  padding: 0 var(--container-padding);
}

/* ===== Typography ===== */

h1, h2, h3, h4 {
  font-family: var(--font-serif);
  font-weight: 600;
  line-height: 1.3;
  color: var(--color-primary);
}

h1 { font-size: var(--text-4xl); }
h2 { font-size: var(--text-3xl); }
h3 { font-size: var(--text-2xl); }
h4 { font-size: var(--text-xl); }

p {
  line-height: 1.8;
  color: var(--color-text-secondary);
}

/* Section Title */
.section-title {
  text-align: center;
  margin-bottom: var(--space-3xl);
}

.section-title h2 {
  margin-bottom: var(--space-md);
  position: relative;
  display: inline-block;
}

.section-title h2::after {
  content: '';
  display: block;
  width: 60px;
  height: 3px;
  background: var(--color-accent);
  margin: var(--space-md) auto 0;
}

.section-title p {
  font-size: var(--text-lg);
  max-width: 700px;
  margin: 0 auto;
}

/* ===== Buttons ===== */

.btn {
  display: inline-flex;
  align-items: center;
  gap: var(--space-sm);
  padding: 0.75rem 2rem;
  font-size: var(--text-base);
  font-weight: 500;
  border-radius: var(--radius-sm);
  transition: all var(--transition-base);
  cursor: pointer;
  border: 2px solid transparent;
}

.btn-primary {
  background: var(--color-accent);
  color: var(--color-bg);
}

.btn-primary:hover {
  background: var(--color-accent-dark);
  transform: translateY(-1px);
}

.btn-outline {
  background: transparent;
  color: var(--color-accent);
  border-color: var(--color-accent);
}

.btn-outline:hover {
  background: var(--color-accent);
  color: var(--color-bg);
}

.btn-white {
  background: rgba(255, 255, 255, 0.15);
  color: #fff;
  border-color: rgba(255, 255, 255, 0.4);
  backdrop-filter: blur(4px);
}

.btn-white:hover {
  background: var(--color-accent);
  border-color: var(--color-accent);
}

/* ===== Header / Navigation ===== */

.header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: var(--nav-height);
  background: var(--color-bg);
  border-bottom: 1px solid var(--color-border);
  z-index: 1000;
  transition: box-shadow var(--transition-base);
}

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

.header .container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 100%;
}

.header-logo {
  flex-shrink: 0;
}

.header-logo img {
  height: 60px;
  width: auto;
}

/* Main Nav */
.main-nav {
  display: flex;
  align-items: center;
  gap: 0;
  height: 100%;
}

.nav-item {
  position: relative;
  height: 100%;
  display: flex;
  align-items: center;
}

.nav-link {
  display: flex;
  align-items: center;
  gap: 4px;
  padding: 0 1rem;
  height: 100%;
  font-size: var(--text-sm);
  font-weight: 500;
  color: var(--color-text);
  transition: color var(--transition-fast);
  white-space: nowrap;
}

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

.nav-link .arrow {
  font-size: 10px;
  transition: transform var(--transition-fast);
}

/* Dropdown */
.dropdown {
  position: absolute;
  top: 100%;
  left: 50%;
  transform: translateX(-50%);
  min-width: 180px;
  background: var(--color-bg);
  border-radius: 0 0 var(--radius-md) var(--radius-md);
  box-shadow: var(--shadow-lg);
  opacity: 0;
  visibility: hidden;
  transform: translateX(-50%) translateY(-8px);
  transition: all var(--transition-base);
  padding: var(--space-sm) 0;
  border-top: 3px solid var(--color-accent);
}

.nav-item:hover .dropdown {
  opacity: 1;
  visibility: visible;
  transform: translateX(-50%) translateY(0);
}

.nav-item:hover .nav-link .arrow {
  transform: rotate(180deg);
}

.dropdown-link {
  display: block;
  padding: 0.6rem 1.5rem;
  font-size: var(--text-sm);
  color: var(--color-text-secondary);
  transition: all var(--transition-fast);
}

.dropdown-link:hover {
  color: var(--color-primary);
  background: var(--color-bg-alt);
  padding-left: 1.8rem;
}

.dropdown-link.external::after {
  content: ' \2197';
  font-size: 12px;
}

/* Search */
.nav-search {
  display: flex;
  align-items: center;
  margin-left: var(--space-md);
}

.lang-toggle-btn {
  min-width: 42px;
  height: 34px;
  padding: 0 10px;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  background: var(--color-bg);
  color: var(--color-text);
  font-size: var(--text-xs);
  font-weight: 700;
  line-height: 1;
  cursor: pointer;
  transition: all var(--transition-fast);
  white-space: nowrap;
}

.lang-toggle-btn:hover {
  border-color: var(--color-primary);
  color: var(--color-primary);
  background: var(--color-bg-alt);
}

.search-toggle {
  width: 40px;
  height: 40px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 50%;
  color: var(--color-text-secondary);
  transition: all var(--transition-fast);
}

.search-toggle:hover {
  background: var(--color-bg-alt);
  color: var(--color-primary);
}

.search-toggle svg {
  width: 18px;
  height: 18px;
}

/* Search Overlay */
.search-overlay {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: rgba(0, 0, 0, 0.6);
  z-index: 2000;
  display: flex;
  align-items: flex-start;
  justify-content: center;
  padding-top: 120px;
  opacity: 0;
  visibility: hidden;
  transition: all var(--transition-base);
}

.search-overlay.active {
  opacity: 1;
  visibility: visible;
}

.search-box {
  width: 90%;
  max-width: 600px;
  background: var(--color-bg);
  border-radius: var(--radius-lg);
  padding: var(--space-lg);
  transform: translateY(-20px);
  transition: transform var(--transition-base);
}

.search-overlay.active .search-box {
  transform: translateY(0);
}

.search-input-wrap {
  display: flex;
  align-items: center;
  gap: var(--space-md);
  border-bottom: 2px solid var(--color-primary);
  padding-bottom: var(--space-sm);
}

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

.search-input-wrap input {
  flex: 1;
  border: none;
  outline: none;
  font-size: var(--text-lg);
  color: var(--color-text);
  background: transparent;
}

.search-input-wrap input::placeholder {
  color: var(--color-text-light);
}

.search-hint {
  margin-top: var(--space-md);
  font-size: var(--text-sm);
  color: var(--color-text-light);
}

/* Language visibility helpers for CMS fields that provide explicit bilingual markup. */
.lang-en {
  display: none;
}

html.en .lang-zh {
  display: none !important;
}

html.en p.lang-en,
html.en div.lang-en,
html.en li.lang-en,
html.en h1.lang-en,
html.en h2.lang-en,
html.en h3.lang-en,
html.en h4.lang-en,
html.en td.lang-en,
html.en th.lang-en,
html.en label.lang-en {
  display: block !important;
}

html.en span.lang-en,
html.en a.lang-en,
html.en strong.lang-en,
html.en em.lang-en,
html.en i.lang-en {
  display: inline !important;
}

/* Mobile Nav */
.mobile-toggle {
  display: none;
  width: 40px;
  height: 40px;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 5px;
}

.mobile-toggle span {
  display: block;
  width: 22px;
  height: 2px;
  background: var(--color-text);
  transition: all var(--transition-base);
}

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

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

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

/* ===== Footer ===== */

.footer {
  background: var(--color-bg-dark);
  color: rgba(255, 255, 255, 0.8);
  padding: 0;
}

/* Footer Top: Brand bar */
.footer-top {
  padding: var(--space-3xl) 0;
  border-bottom: 1px solid rgba(255, 255, 255, 0.1);
}

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

.footer-brand .footer-logo {
  height: 68px;
  width: auto;
  flex-shrink: 0;
}

.footer-brand-text {
  display: flex;
  flex-direction: column;
}

.footer-brand-name {
  font-family: var(--font-serif);
  font-size: var(--text-xl);
  font-weight: 600;
  color: #fff;
  letter-spacing: 0.05em;
}

.footer-brand-en {
  font-size: var(--text-sm);
  color: rgba(255, 255, 255, 0.45);
  margin-top: 2px;
  letter-spacing: 0.03em;
}

.footer-desc {
  color: rgba(255, 255, 255, 0.55);
  font-size: var(--text-sm);
  line-height: 1.8;
  max-width: 700px;
}

/* Footer Grid: 4 columns */
.footer-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: var(--space-2xl);
  padding: var(--space-2xl) 0;
  border-bottom: 1px solid rgba(255, 255, 255, 0.1);
}

.footer-links h4 {
  color: var(--color-accent);
  font-size: var(--text-base);
  font-family: var(--font-sans);
  font-weight: 600;
  margin-bottom: var(--space-lg);
}

.footer-links ul {
  display: flex;
  flex-direction: column;
  gap: var(--space-sm);
}

.footer-links a {
  font-size: var(--text-sm);
  color: rgba(255, 255, 255, 0.55);
  transition: all var(--transition-fast);
}

.footer-links a:hover {
  color: var(--color-accent);
  padding-left: 4px;
}

.footer-contact-item {
  display: flex;
  align-items: flex-start;
  gap: var(--space-sm);
  margin-bottom: var(--space-md);
  font-size: var(--text-sm);
  color: rgba(255, 255, 255, 0.55);
}

.footer-contact-item svg {
  width: 16px;
  height: 16px;
  flex-shrink: 0;
  margin-top: 3px;
  color: var(--color-accent);
}

/* Footer Bottom */
.footer-bottom {
  padding: var(--space-lg) 0;
  text-align: center;
  font-size: var(--text-xs);
  color: rgba(255, 255, 255, 0.35);
}

/* ===== Back to Top ===== */

.back-to-top {
  position: fixed;
  bottom: 2rem;
  right: 2rem;
  width: 44px;
  height: 44px;
  background: var(--color-primary);
  color: #fff;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  box-shadow: var(--shadow-md);
  opacity: 0;
  visibility: hidden;
  transition: all var(--transition-base);
  z-index: 900;
}

.back-to-top.visible {
  opacity: 1;
  visibility: visible;
}

.back-to-top:hover {
  background: var(--color-primary-light);
  transform: translateY(-2px);
}

.back-to-top svg {
  width: 20px;
  height: 20px;
}

/* ===== Scroll Animation ===== */

.fade-in {
  opacity: 0;
  transform: translateY(30px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}

.fade-in.visible {
  opacity: 1;
  transform: translateY(0);
}

/* ===== Page content offset for fixed nav ===== */

main {
  padding-top: var(--nav-height);
}