/* ===== China World Travel — Design System ===== */
/* Dark, sophisticated, premium travel agency aesthetic */

:root,
[data-theme='light'] {
  /* Type Scale */
  --text-xs: clamp(0.75rem, 0.7rem + 0.25vw, 0.875rem);
  --text-sm: clamp(0.875rem, 0.8rem + 0.35vw, 1rem);
  --text-base: clamp(1rem, 0.95rem + 0.25vw, 1.125rem);
  --text-lg: clamp(1.125rem, 1rem + 0.75vw, 1.5rem);
  --text-xl: clamp(1.5rem, 1.2rem + 1.25vw, 2.25rem);
  --text-2xl: clamp(2rem, 1.2rem + 2.5vw, 3.5rem);
  --text-3xl: clamp(2.5rem, 1rem + 4vw, 5rem);
  --text-hero: clamp(3rem, 0.5rem + 7vw, 8rem);

  /* Spacing */
  --space-1: 0.25rem; --space-2: 0.5rem; --space-3: 0.75rem;
  --space-4: 1rem; --space-5: 1.25rem; --space-6: 1.5rem;
  --space-8: 2rem; --space-10: 2.5rem; --space-12: 3rem;
  --space-16: 4rem; --space-20: 5rem; --space-24: 6rem;
  --space-32: 8rem;

  /* Surfaces — dark charcoal/slate */
  --color-bg: #0d1117;
  --color-surface: #131820;
  --color-surface-2: #1a2029;
  --color-surface-offset: #161b24;
  --color-surface-offset-2: #1c2230;
  --color-surface-dynamic: #232b38;
  --color-divider: #2a3441;
  --color-border: #303a48;

  /* Text — warm gray on dark */
  --color-text: #e4e6eb;
  --color-text-muted: #8b95a7;
  --color-text-faint: #5a6577;
  --color-text-inverse: #0d1117;

  /* Primary — vivid blue */
  --color-primary: #2B8AE5;
  --color-primary-hover: #1A6FC4;
  --color-primary-active: #0D4378;
  --color-primary-highlight: #1a2a38;

  /* Accent — deep teal for secondary */
  --color-accent: #2d7a7a;
  --color-accent-hover: #236161;

  /* Radius */
  --radius-sm: 0.375rem; --radius-md: 0.5rem;
  --radius-lg: 0.75rem; --radius-xl: 1rem; --radius-full: 9999px;

  --transition-interactive: 180ms cubic-bezier(0.16, 1, 0.3, 1);

  --shadow-sm: 0 1px 2px rgba(0,0,0,0.3);
  --shadow-md: 0 4px 12px rgba(0,0,0,0.35);
  --shadow-lg: 0 12px 32px rgba(0,0,0,0.45);

  --content-narrow: 640px;
  --content-default: 960px;
  --content-wide: 1200px;
  --content-full: 100%;

  /* Fonts */
  --font-display: 'Cormorant Garamond', Georgia, serif;
  --font-body: 'Inter', 'Helvetica Neue', sans-serif;
}

/* Light mode override */
[data-theme='light'] {
  --color-bg: #f7f5f0;
  --color-surface: #fbf9f5;
  --color-surface-2: #ffffff;
  --color-surface-offset: #f1eee6;
  --color-surface-offset-2: #ebe7dc;
  --color-surface-dynamic: #e4dfd1;
  --color-divider: #ded8c8;
  --color-border: #d0c9b5;
  --color-text: #211f19;
  --color-text-muted: #5c5748;
  --color-text-faint: #948d78;
  --color-text-inverse: #f7f5f0;
  --color-primary: #2B8AE5;
  --color-primary-hover: #1A6FC4;
  --color-primary-active: #0D4378;
  --color-primary-highlight: #d0e8f7;
  --shadow-sm: 0 1px 2px rgba(0,0,0,0.06);
  --shadow-md: 0 4px 12px rgba(0,0,0,0.08);
  --shadow-lg: 0 12px 32px rgba(0,0,0,0.12);
}
[data-theme='light'] .hero-bg::after {
  background: linear-gradient(180deg, rgba(247,245,240,0.35) 0%, rgba(247,245,240,0.55) 50%, rgba(247,245,240,0.75) 100%);
}
[data-theme='light'] .whatsapp-card-icon { background: #1a5c3a; }

/* ===== Base Layout ===== */
.container {
  max-width: var(--content-default);
  margin-inline: auto;
  padding-inline: var(--space-4);
}
.container-wide {
  max-width: var(--content-wide);
  margin-inline: auto;
  padding-inline: var(--space-4);
}

/* ===== Header ===== */
.header {
  position: sticky;
  top: 0;
  z-index: 50;
  background: oklch(from var(--color-bg) l c h / 0.85);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--color-divider);
  transition: transform 0.3s cubic-bezier(0.16,1,0.3,1);
}
.header--hidden { transform: translateY(-100%); }
.header-inner {
  max-width: var(--content-wide);
  margin-inline: auto;
  padding: var(--space-3) var(--space-4);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-4);
}
.logo {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  text-decoration: none;
  color: var(--color-text);
}
.logo-mark {
  width: 52px;
  height: auto;
  flex-shrink: 0;
  border-radius: var(--radius-sm);
}
.logo-text {
  font-family: var(--font-display);
  font-size: var(--text-xl);
  font-weight: 600;
  letter-spacing: 0.02em;
  line-height: 1.2;
}
.logo-text span {
  display: block;
  font-family: var(--font-body);
  font-size: 0.55rem;
  font-weight: 400;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--color-text-muted);
  margin-top: 2px;
  opacity: 0.6;
}
.nav {
  display: none;
  align-items: center;
  gap: var(--space-6);
}
.nav a {
  font-size: var(--text-sm);
  color: var(--color-text-muted);
  text-decoration: none;
  font-weight: 500;
}
.nav a:hover { color: var(--color-primary); }
.header-actions {
  display: flex;
  align-items: center;
  gap: var(--space-3);
}
.lang-toggle {
  display: flex;
  align-items: center;
  gap: 2px;
  font-size: var(--text-sm);
  color: var(--color-text-muted);
  cursor: pointer;
  background: none;
  border: none;
  font-weight: 500;
}
.lang-toggle .active { color: var(--color-primary); }
.lang-toggle span { padding: 2px 4px; }
.menu-btn {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 44px;
  height: 44px;
  color: var(--color-text);
  background: none;
  border: none;
}

@media (min-width: 768px) {
  .nav { display: flex; }
  .menu-btn { display: none; }
}

/* Mobile menu */
.mobile-menu {
  display: none;
  position: fixed;
  top: 0;
  right: 0;
  width: 100%;
  max-width: 360px;
  height: 100dvh;
  background: var(--color-surface);
  border-left: 1px solid var(--color-divider);
  padding: var(--space-12) var(--space-6);
  z-index: 100;
  flex-direction: column;
  gap: var(--space-4);
  transform: translateX(100%);
  transition: transform 0.3s cubic-bezier(0.16,1,0.3,1);
}
.mobile-menu.open {
  display: flex;
  transform: translateX(0);
}
.mobile-menu a {
  font-size: var(--text-lg);
  color: var(--color-text);
  text-decoration: none;
  padding: var(--space-2) 0;
  border-bottom: 1px solid var(--color-divider);
}
.mobile-menu a:hover { color: var(--color-primary); }
.mobile-menu-close {
  position: absolute;
  top: var(--space-4);
  right: var(--space-4);
  width: 44px;
  height: 44px;
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--color-text);
  background: none;
  border: none;
}
.overlay {
  display: none;
  position: fixed;
  inset: 0;
  background: rgba(0,0,0,0.6);
  z-index: 99;
}
.overlay.show { display: block; }

/* ===== Hero ===== */
.hero {
  position: relative;
  min-height: 90vh;
  display: flex;
  align-items: center;
  overflow: hidden;
}
.hero-bg {
  position: absolute;
  inset: 0;
  z-index: 0;
}
.hero-bg img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}
.hero-bg::after {
  content: '';
  position: absolute;
  inset: 0;
  background: linear-gradient(180deg,
    rgba(13,17,23,0.6) 0%,
    rgba(13,17,23,0.75) 50%,
    rgba(13,17,23,0.9) 100%
  );
}
.hero-content {
  position: relative;
  z-index: 1;
  max-width: var(--content-wide);
  margin-inline: auto;
  padding: var(--space-20) var(--space-4);
  width: 100%;
}
.hero-eyebrow {
  font-size: var(--text-xs);
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--color-primary);
  font-weight: 600;
  margin-bottom: var(--space-4);
}
.hero-title {
  font-family: var(--font-display);
  font-size: var(--text-hero);
  font-weight: 500;
  line-height: 1.05;
  color: var(--color-text);
  max-width: 14ch;
  margin-bottom: var(--space-6);
}
.hero-subtitle {
  font-size: var(--text-base);
  color: var(--color-text-muted);
  max-width: 52ch;
  line-height: 1.7;
  margin-bottom: var(--space-8);
}
.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-3);
}
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-2);
  padding: var(--space-3) var(--space-6);
  font-size: var(--text-sm);
  font-weight: 600;
  text-decoration: none;
  border-radius: var(--radius-full);
  transition: all var(--transition-interactive);
  min-height: 44px;
}
.btn-primary {
  background: var(--color-primary);
  color: var(--color-text-inverse);
}
.btn-primary:hover {
  background: var(--color-primary-hover);
}
.btn-outline {
  background: transparent;
  color: var(--color-text);
  border: 1px solid var(--color-border);
}
.btn-outline:hover {
  border-color: var(--color-primary);
  color: var(--color-primary);
}

/* ===== Section Base ===== */
.section {
  padding-block: clamp(var(--space-12), 6vw, var(--space-24));
}
.section-dark {
  background: var(--color-surface);
}
.section-eyebrow {
  font-size: var(--text-xs);
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--color-primary);
  font-weight: 600;
  margin-bottom: var(--space-3);
}
.section-title {
  font-family: var(--font-display);
  font-size: var(--text-2xl);
  font-weight: 500;
  line-height: 1.1;
  color: var(--color-text);
  margin-bottom: var(--space-4);
}
.section-intro {
  font-size: var(--text-base);
  color: var(--color-text-muted);
  max-width: 60ch;
  line-height: 1.7;
  margin-bottom: var(--space-12);
}

/* ===== Services Grid ===== */
.services-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-4);
}
@media (min-width: 640px) {
  .services-grid { grid-template-columns: repeat(2, 1fr); }
}
@media (min-width: 1024px) {
  .services-grid { grid-template-columns: repeat(3, 1fr); }
}
.service-card {
  background: var(--color-surface-2);
  border: 1px solid var(--color-divider);
  border-radius: var(--radius-lg);
  overflow: hidden;
  transition: border-color var(--transition-interactive), transform var(--transition-interactive);
  display: flex;
  flex-direction: column;
}
.service-card:hover {
  border-color: var(--color-primary);
  transform: translateY(-2px);
}
.service-card-img {
  width: 100%;
  aspect-ratio: 3/2;
  overflow: hidden;
}
.service-card-img img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform 0.6s cubic-bezier(0.16,1,0.3,1);
}
.service-card:hover .service-card-img img {
  transform: scale(1.05);
}
.service-card h3 {
  font-size: var(--text-lg);
  font-weight: 600;
  color: var(--color-text);
  margin-bottom: var(--space-2);
  padding: 0 var(--space-6);
}
.service-card p {
  font-size: var(--text-sm);
  color: var(--color-text-muted);
  line-height: 1.6;
  padding: 0 var(--space-6);
  margin-bottom: var(--space-6);
}
.service-number {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 32px;
  height: 32px;
  border-radius: var(--radius-full);
  background: var(--color-primary-highlight);
  color: var(--color-primary);
  font-size: var(--text-sm);
  font-weight: 700;
  margin: var(--space-4) var(--space-6) var(--space-2);
  font-family: var(--font-body);
}

/* ===== About / Highlight ===== */
.about {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-8);
  align-items: center;
}
@media (min-width: 768px) {
  .about { grid-template-columns: 1fr 1fr; gap: var(--space-12); }
}
.about-image {
  border-radius: var(--radius-xl);
  overflow: hidden;
  aspect-ratio: 4/3;
}
.about-image img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}
.about-content h2 {
  font-family: var(--font-display);
  font-size: var(--text-2xl);
  font-weight: 500;
  line-height: 1.1;
  margin-bottom: var(--space-4);
}
.about-content p {
  font-size: var(--text-base);
  color: var(--color-text-muted);
  line-height: 1.7;
  margin-bottom: var(--space-4);
}
.about-features {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-6);
  margin-top: var(--space-6);
}
.about-feature {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  font-size: var(--text-sm);
  color: var(--color-text);
}
.about-feature svg {
  width: 20px;
  height: 20px;
  color: var(--color-primary);
  flex-shrink: 0;
}

/* ===== Clients ===== */
.clients-marquee {
  overflow: hidden;
  position: relative;
  padding-block: var(--space-8);
}
.clients-marquee::before,
.clients-marquee::after {
  content: '';
  position: absolute;
  top: 0;
  bottom: 0;
  width: 80px;
  z-index: 2;
  pointer-events: none;
}
.clients-marquee::before {
  left: 0;
  background: linear-gradient(90deg, var(--color-bg), transparent);
}
.clients-marquee::after {
  right: 0;
  background: linear-gradient(270deg, var(--color-bg), transparent);
}
.clients-track {
  display: flex;
  gap: var(--space-12);
  width: max-content;
  animation: scroll 40s linear infinite;
}
@keyframes scroll {
  to { transform: translateX(-50%); }
}
.client-logo {
  font-size: var(--text-lg);
  font-weight: 600;
  color: var(--color-text-muted);
  white-space: nowrap;
  font-family: var(--font-display);
  letter-spacing: 0.02em;
  opacity: 0.7;
  transition: opacity var(--transition-interactive);
}
.client-logo:hover { opacity: 1; color: var(--color-primary); }

.clients-section-label {
  text-align: center;
  font-size: var(--text-xs);
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--color-text-faint);
  font-weight: 600;
  margin-bottom: var(--space-4);
}

/* ===== Gallery ===== */
.gallery-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: var(--space-3);
}
@media (min-width: 768px) {
  .gallery-grid {
    grid-template-columns: repeat(3, 1fr);
    gap: var(--space-4);
  }
}
.gallery-item {
  position: relative;
  overflow: hidden;
  border-radius: var(--radius-lg);
  aspect-ratio: 1/1;
}
.gallery-item.gallery-large {
  grid-column: span 2;
  aspect-ratio: 16/9;
}
@media (min-width: 768px) {
  .gallery-item.gallery-large {
    grid-column: span 2;
    grid-row: span 2;
    aspect-ratio: 1/1;
  }
}
.gallery-item.gallery-wide {
  grid-column: span 2;
  aspect-ratio: 16/9;
}
.gallery-item img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform 0.6s cubic-bezier(0.16,1,0.3,1);
}
.gallery-item:hover img {
  transform: scale(1.05);
}
.gallery-caption {
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  padding: var(--space-6) var(--space-4) var(--space-3);
  background: linear-gradient(180deg, transparent, rgba(13,17,23,0.85));
  display: flex;
  flex-direction: column;
  gap: 2px;
}
.caption-zh {
  font-size: var(--text-base);
  font-weight: 600;
  color: #fff;
}
.caption-en {
  font-size: var(--text-xs);
  color: var(--color-text-muted);
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

/* ===== Contact ===== */
.contact {
  background: var(--color-surface);
}
.contact-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-8);
}
@media (min-width: 768px) {
  .contact-grid { grid-template-columns: 1fr 1fr; }
}
.contact-info h2 {
  font-family: var(--font-display);
  font-size: var(--text-2xl);
  font-weight: 500;
  line-height: 1.1;
  margin-bottom: var(--space-4);
}
.contact-info p {
  color: var(--color-text-muted);
  line-height: 1.7;
  margin-bottom: var(--space-6);
}
.contact-methods {
  display: flex;
  flex-direction: column;
  gap: var(--space-4);
}
.contact-method {
  display: flex;
  align-items: center;
  gap: var(--space-4);
  text-decoration: none;
  color: var(--color-text);
}
.contact-method-icon {
  width: 48px;
  height: 48px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: var(--radius-full);
  background: var(--color-surface-offset);
  border: 1px solid var(--color-divider);
  flex-shrink: 0;
}
.contact-method-icon svg {
  width: 22px;
  height: 22px;
  color: var(--color-primary);
}
.contact-method-label {
  font-size: var(--text-xs);
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--color-text-faint);
  font-weight: 600;
}
.contact-method-value {
  font-size: var(--text-base);
  color: var(--color-text);
  font-weight: 500;
}
.contact-method:hover .contact-method-value { color: var(--color-primary); }

/* WhatsApp highlight card */
.whatsapp-card {
  background: var(--color-surface-2);
  border: 1px solid var(--color-divider);
  border-radius: var(--radius-lg);
  padding: var(--space-6);
  display: flex;
  align-items: center;
  gap: var(--space-4);
}
.whatsapp-card-icon {
  width: 56px;
  height: 56px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: var(--radius-full);
  background: #1a5c3a;
  flex-shrink: 0;
}
.whatsapp-card-icon svg {
  width: 28px;
  height: 28px;
  color: #fff;
}
.whatsapp-card-title {
  font-size: var(--text-base);
  font-weight: 600;
  color: var(--color-text);
}
.whatsapp-card-sub {
  font-size: var(--text-sm);
  color: var(--color-text-muted);
}

/* ===== Footer ===== */
.footer {
  background: var(--color-surface-offset);
  border-top: 1px solid var(--color-divider);
  padding-block: var(--space-12) var(--space-8);
}
.footer-inner {
  max-width: var(--content-wide);
  margin-inline: auto;
  padding-inline: var(--space-4);
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-8);
}
@media (min-width: 768px) {
  .footer-inner { grid-template-columns: 2fr 1fr 1fr; }
}
.footer-logo {
  width: 120px;
  height: auto;
  margin-bottom: var(--space-4);
  border-radius: var(--radius-sm);
}
.footer-brand h3 {
  font-family: var(--font-display);
  font-size: var(--text-lg);
  font-weight: 600;
  margin-bottom: var(--space-2);
}
.footer-brand p {
  font-size: var(--text-sm);
  color: var(--color-text-muted);
  max-width: 40ch;
  line-height: 1.6;
}
.footer-col h4 {
  font-size: var(--text-xs);
  letter-spacing: 0.15em;
  text-transform: uppercase;
  color: var(--color-text-faint);
  font-weight: 600;
  margin-bottom: var(--space-3);
}
.footer-col ul {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: var(--space-2);
}
.footer-col a {
  font-size: var(--text-sm);
  color: var(--color-text-muted);
  text-decoration: none;
}
.footer-col a:hover { color: var(--color-primary); }
.footer-bottom {
  max-width: var(--content-wide);
  margin-inline: auto;
  padding: var(--space-6) var(--space-4) 0;
  border-top: 1px solid var(--color-divider);
  margin-top: var(--space-8);
  text-align: center;
  font-size: var(--text-xs);
  color: var(--color-text-faint);
}

/* ===== Language Toggle (i18n) ===== */
[data-lang="en"] [data-i18n-zh] { display: none; }
[data-lang="zh"] [data-i18n-en] { display: none; }

/* ===== Theme Toggle ===== */
.theme-toggle {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 40px;
  height: 40px;
  color: var(--color-text-muted);
  background: none;
  border: none;
  border-radius: var(--radius-full);
  transition: color var(--transition-interactive), background var(--transition-interactive);
}
.theme-toggle:hover {
  color: var(--color-primary);
  background: var(--color-surface-offset);
}

/* ===== Scroll Reveal ===== */
.reveal {
  opacity: 0;
  transform: translateY(24px);
  transition: opacity 0.6s cubic-bezier(0.16,1,0.3,1), transform 0.6s cubic-bezier(0.16,1,0.3,1);
}
.reveal.visible {
  opacity: 1;
  transform: translateY(0);
}
/* Fallback: if JS fails, content still visible after 2s */
@keyframes reveal-fallback {
  to { opacity: 1; transform: translateY(0); }
}
.reveal {
  animation: reveal-fallback 0.01ms 2s forwards;
}

/* ===== Floating WhatsApp Button ===== */
.float-wa {
  position: fixed;
  bottom: var(--space-4);
  right: var(--space-4);
  z-index: 60;
  width: 56px;
  height: 56px;
  border-radius: var(--radius-full);
  background: #1a5c3a;
  display: flex;
  align-items: center;
  justify-content: center;
  box-shadow: var(--shadow-lg);
  color: #fff;
  transition: transform var(--transition-interactive), background var(--transition-interactive);
}
.float-wa:hover {
  transform: scale(1.08);
  background: #237a4e;
}
.float-wa svg { width: 28px; height: 28px; }