/* ==========================================================================
   VietLegacy - Main Stylesheet
   ========================================================================== */

/* ==========================================================================
   Base Styles
   ========================================================================== */

html {
  scroll-behavior: smooth;
}

body {
  font-family: var(--font-body);
  font-size: var(--text-base);
  color: var(--color-gray-700);
  background-color: var(--color-white);
  overflow-x: hidden;
}

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

.header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: var(--z-sticky);
  transition: all var(--transition-base);
  height: var(--header-height-mobile);
}

.header--transparent {
  background-color: transparent;
}

.header--solid {
  background-color: var(--color-white);
  box-shadow: var(--shadow-md);
}

.header__container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 100%;
  padding: 0 var(--space-4);
  max-width: var(--container-xl);
  margin: 0 auto;
}

@media (min-width: 768px) {
  .header {
    height: var(--header-height);
  }

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

/* Navigation */
.nav {
  display: none;
}

.nav--active {
  display: flex;
  flex-direction: column;
  position: fixed;
  top: var(--header-height-mobile);
  left: 0;
  right: 0;
  bottom: 0;
  background-color: var(--color-white);
  padding: var(--space-6);
  z-index: var(--z-modal);
  overflow-y: auto;
}

.nav__list {
  display: flex;
  flex-direction: column;
  gap: var(--space-1);
  list-style: none;
}

.nav__item {
  position: relative;
}

.nav__link {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: var(--space-3) var(--space-4);
  font-size: var(--text-base);
  font-weight: var(--font-medium);
  color: var(--color-gray-700);
  text-decoration: none;
  border-radius: var(--radius-md);
  transition: all var(--transition-fast);
}

.nav__link:hover,
.nav__link--active {
  color: var(--color-primary);
  background-color: var(--color-gray-50);
}

.nav__arrow {
  width: 1rem;
  height: 1rem;
  transition: transform var(--transition-fast);
}

.nav__item--open .nav__arrow {
  transform: rotate(180deg);
}

/* Dropdown */
.nav__dropdown {
  display: none;
  list-style: none;
  padding-left: var(--space-4);
}

.nav__item--open .nav__dropdown {
  display: block;
}

.nav__dropdown-link {
  display: block;
  padding: var(--space-2) var(--space-4);
  font-size: var(--text-sm);
  color: var(--color-gray-600);
  text-decoration: none;
  border-radius: var(--radius-md);
  transition: all var(--transition-fast);
}

.nav__dropdown-link:hover {
  color: var(--color-primary);
  background-color: var(--color-gray-50);
}

/* Mobile Menu Toggle */
.nav-toggle {
  display: flex;
  flex-direction: column;
  justify-content: center;
  gap: 5px;
  width: 32px;
  height: 32px;
  padding: 4px;
  cursor: pointer;
}

.nav-toggle__bar {
  width: 100%;
  height: 2px;
  background-color: var(--color-gray-700);
  border-radius: 2px;
  transition: all var(--transition-fast);
}

.header--transparent .nav-toggle__bar {
  background-color: var(--color-white);
}

.header--solid .nav-toggle__bar {
  background-color: var(--color-gray-700);
}

.nav-toggle--active .nav-toggle__bar:nth-child(1) {
  transform: translateY(7px) rotate(45deg);
}

.nav-toggle--active .nav-toggle__bar:nth-child(2) {
  opacity: 0;
}

.nav-toggle--active .nav-toggle__bar:nth-child(3) {
  transform: translateY(-7px) rotate(-45deg);
}

/* Header Actions */
.header__actions {
  display: flex;
  align-items: center;
  gap: var(--space-4);
}

/* Language Toggle */
.lang-toggle {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  font-size: var(--text-sm);
  font-weight: var(--font-medium);
}

.lang-toggle__link {
  color: var(--color-gray-500);
  text-decoration: none;
  padding: var(--space-1) var(--space-2);
  border-radius: var(--radius-sm);
  transition: all var(--transition-fast);
}

.lang-toggle__link:hover,
.lang-toggle__link--active {
  color: var(--color-primary);
}

.header--transparent .lang-toggle__link {
  color: rgba(255, 255, 255, 0.7);
}

.header--transparent .lang-toggle__link:hover,
.header--transparent .lang-toggle__link--active {
  color: var(--color-white);
}

.lang-toggle__divider {
  color: var(--color-gray-300);
}

.header--transparent .lang-toggle__divider {
  color: rgba(255, 255, 255, 0.5);
}

/* Desktop Navigation */
@media (min-width: 1024px) {
  .nav {
    display: flex;
    align-items: center;
  }

  .nav__list {
    flex-direction: row;
    gap: var(--space-1);
  }

  .nav__link {
    padding: var(--space-2) var(--space-4);
  }

  .header--transparent .nav__link {
    color: var(--color-white);
  }

  .header--transparent .nav__link:hover {
    color: var(--color-white);
    background-color: rgba(255, 255, 255, 0.1);
  }

  .header--solid .nav__link {
    color: var(--color-gray-700);
  }

  .header--solid .nav__link:hover {
    color: var(--color-primary);
    background-color: var(--color-gray-50);
  }

  /* Desktop Dropdown */
  .nav__item--has-dropdown {
    position: relative;
  }

  .nav__dropdown {
    display: none;
    position: absolute;
    top: 100%;
    left: 0;
    min-width: 220px;
    padding: var(--space-2);
    background-color: var(--color-white);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-xl);
    z-index: var(--z-dropdown);
  }

  .nav__item--has-dropdown:hover .nav__dropdown {
    display: block;
  }

  .nav__dropdown-link {
    padding: var(--space-3) var(--space-4);
    font-size: var(--text-base);
    color: var(--color-gray-700);
  }

  .nav-toggle {
    display: none;
  }
}

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

.footer {
  background-color: var(--color-gray-900);
  color: var(--color-white);
  padding: var(--space-16) 0 var(--space-8);
}

.footer__grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-10);
  margin-bottom: var(--space-12);
}

.footer__brand {
  max-width: 300px;
}

.footer__logo {
  margin-bottom: var(--space-4);
}

.footer__description {
  font-size: var(--text-sm);
  color: var(--color-gray-400);
  margin-bottom: var(--space-6);
  line-height: var(--leading-relaxed);
}

.footer__social {
  display: flex;
  gap: var(--space-4);
}

.footer__social-link {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 40px;
  height: 40px;
  border-radius: var(--radius-full);
  background-color: rgba(255, 255, 255, 0.1);
  color: var(--color-white);
  transition: all var(--transition-fast);
}

.footer__social-link:hover {
  background-color: var(--color-primary);
  transform: translateY(-2px);
}

.footer__social-icon {
  width: 20px;
  height: 20px;
}

/* Footer Columns */
.footer__column-title {
  font-family: var(--font-heading);
  font-size: var(--text-lg);
  font-weight: var(--font-semibold);
  color: var(--color-white);
  margin-bottom: var(--space-4);
}

.footer__links {
  list-style: none;
}

.footer__link-item {
  margin-bottom: var(--space-3);
}

.footer__link {
  font-size: var(--text-sm);
  color: var(--color-gray-400);
  text-decoration: none;
  transition: color var(--transition-fast);
}

.footer__link:hover {
  color: var(--color-white);
}

/* Footer Contact */
.footer__contact-item {
  display: flex;
  align-items: flex-start;
  gap: var(--space-3);
  margin-bottom: var(--space-4);
  font-size: var(--text-sm);
  color: var(--color-gray-400);
}

.footer__contact-icon {
  width: 20px;
  height: 20px;
  flex-shrink: 0;
  color: var(--color-primary);
  margin-top: 2px;
}

.footer__contact-text a {
  color: var(--color-gray-400);
  text-decoration: none;
  transition: color var(--transition-fast);
}

.footer__contact-text a:hover {
  color: var(--color-white);
}

/* Footer CTA */
.footer__cta {
  margin-top: var(--space-6);
}

/* Footer Bottom */
.footer__bottom {
  display: flex;
  flex-direction: column;
  gap: var(--space-4);
  padding-top: var(--space-8);
  border-top: 1px solid rgba(255, 255, 255, 0.1);
}

.footer__copyright {
  font-size: var(--text-sm);
  color: var(--color-gray-500);
}

.footer__legal {
  display: flex;
  gap: var(--space-6);
  list-style: none;
}

.footer__legal-link {
  font-size: var(--text-sm);
  color: var(--color-gray-500);
  text-decoration: none;
  transition: color var(--transition-fast);
}

.footer__legal-link:hover {
  color: var(--color-white);
}

@media (min-width: 768px) {
  .footer__grid {
    grid-template-columns: repeat(2, 1fr);
  }

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

@media (min-width: 1024px) {
  .footer__grid {
    grid-template-columns: 1.5fr 1fr 1fr 1fr;
  }
}

/* ==========================================================================
   Hero Section
   ========================================================================== */

.hero {
  position: relative;
  min-height: 100vh;
  display: flex;
  align-items: center;
  padding-top: var(--header-height-mobile);
  background: linear-gradient(135deg, var(--color-primary) 0%, var(--color-primary-dark) 50%, #6B1425 100%);
  overflow: hidden;
}

.hero::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background-image: url("data:image/svg+xml,%3Csvg width='60' height='60' viewBox='0 0 60 60' xmlns='http://www.w3.org/2000/svg'%3E%3Cg fill='none' fill-rule='evenodd'%3E%3Cg fill='%23ffffff' fill-opacity='0.03'%3E%3Cpath d='M36 34v-4h-2v4h-4v2h4v4h2v-4h4v-2h-4zm0-30V0h-2v4h-4v2h4v4h2V6h4V4h-4zM6 34v-4H4v4H0v2h4v4h2v-4h4v-2H6zM6 4V0H4v4H0v2h4v4h2V6h4V4H6z'/%3E%3C/g%3E%3C/g%3E%3C/svg%3E");
  opacity: 0.5;
}

.hero__container {
  position: relative;
  z-index: 1;
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-10);
  align-items: center;
}

.hero__content {
  text-align: center;
  color: var(--color-white);
}

.hero__badge {
  display: inline-block;
  padding: var(--space-2) var(--space-4);
  background-color: rgba(255, 215, 0, 0.2);
  color: var(--color-gold);
  font-size: var(--text-sm);
  font-weight: var(--font-medium);
  border-radius: var(--radius-full);
  margin-bottom: var(--space-6);
}

.hero__title {
  font-family: var(--font-heading);
  font-size: var(--text-4xl);
  font-weight: var(--font-bold);
  line-height: var(--leading-tight);
  margin-bottom: var(--space-6);
}

.hero__title-highlight {
  color: var(--color-gold);
}

.hero__subtitle {
  font-size: var(--text-lg);
  opacity: 0.9;
  margin-bottom: var(--space-8);
  max-width: 540px;
  margin-left: auto;
  margin-right: auto;
}

.hero__cta {
  display: flex;
  flex-direction: column;
  gap: var(--space-4);
}

.hero__visual {
  display: none;
}

.hero__image {
  max-width: 100%;
  height: auto;
  border-radius: var(--radius-xl);
  box-shadow: var(--shadow-2xl);
}

@media (min-width: 768px) {
  .hero {
    padding-top: var(--header-height);
  }

  .hero__title {
    font-size: var(--text-5xl);
  }

  .hero__cta {
    flex-direction: row;
    justify-content: center;
  }
}

@media (min-width: 1024px) {
  .hero__container {
    grid-template-columns: 1fr 1fr;
    gap: var(--space-16);
  }

  .hero__content {
    text-align: left;
  }

  .hero__subtitle {
    margin-left: 0;
    margin-right: 0;
  }

  .hero__cta {
    justify-content: flex-start;
  }

  .hero__visual {
    display: block;
  }

  .hero__title {
    font-size: var(--text-6xl);
  }
}

/* ==========================================================================
   Value Props Section
   ========================================================================== */

.value-props {
  background-color: var(--color-gray-50);
}

.value-props__grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-6);
}

.value-card {
  background-color: var(--color-white);
  padding: var(--space-8);
  border-radius: var(--radius-lg);
  text-align: center;
  box-shadow: var(--shadow-md);
  transition: all var(--transition-base);
}

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

.value-card__icon {
  width: 64px;
  height: 64px;
  margin: 0 auto var(--space-4);
  color: var(--color-primary);
}

.value-card__title {
  font-family: var(--font-heading);
  font-size: var(--text-xl);
  font-weight: var(--font-semibold);
  color: var(--color-gray-900);
  margin-bottom: var(--space-3);
}

.value-card__description {
  font-size: var(--text-base);
  color: var(--color-gray-600);
  line-height: var(--leading-relaxed);
}

@media (min-width: 640px) {
  .value-props__grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

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

/* ==========================================================================
   Products Section
   ========================================================================== */

.products__grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-6);
}

.product-card {
  background-color: var(--color-white);
  border-radius: var(--radius-xl);
  padding: var(--space-8);
  box-shadow: var(--shadow-md);
  text-align: center;
  transition: all var(--transition-base);
  border: 2px solid transparent;
}

.product-card:hover {
  transform: translateY(-6px);
  box-shadow: var(--shadow-xl);
  border-color: var(--color-primary-light);
}

.product-card__icon {
  width: 80px;
  height: 80px;
  margin: 0 auto var(--space-5);
  color: var(--color-primary);
}

.product-card__name {
  font-family: var(--font-heading);
  font-size: var(--text-xl);
  font-weight: var(--font-bold);
  color: var(--color-gray-900);
  margin-bottom: var(--space-2);
}

.product-card__tagline {
  font-size: var(--text-sm);
  color: var(--color-gray-500);
  margin-bottom: var(--space-4);
}

.product-card__price {
  font-size: var(--text-2xl);
  font-weight: var(--font-bold);
  color: var(--color-primary);
  margin-bottom: var(--space-1);
}

.product-card__timeline {
  font-size: var(--text-sm);
  color: var(--color-gray-500);
  margin-bottom: var(--space-6);
}

.product-card__features {
  list-style: none;
  text-align: left;
  margin-bottom: var(--space-6);
}

.product-card__feature {
  display: flex;
  align-items: flex-start;
  gap: var(--space-3);
  padding: var(--space-2) 0;
  font-size: var(--text-sm);
  color: var(--color-gray-600);
}

.product-card__feature-icon {
  width: 20px;
  height: 20px;
  flex-shrink: 0;
  color: var(--color-success);
}

@media (min-width: 640px) {
  .products__grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

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

/* ==========================================================================
   Case Studies Section
   ========================================================================== */

.case-studies__grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-8);
}

.case-card {
  background-color: var(--color-white);
  border-radius: var(--radius-xl);
  overflow: hidden;
  box-shadow: var(--shadow-md);
  transition: all var(--transition-base);
}

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

.case-card__image {
  width: 100%;
  aspect-ratio: 16 / 9;
  object-fit: cover;
}

.case-card__content {
  padding: var(--space-6);
}

.case-card__logo {
  height: 32px;
  width: auto;
  margin-bottom: var(--space-4);
}

.case-card__title {
  font-family: var(--font-heading);
  font-size: var(--text-xl);
  font-weight: var(--font-semibold);
  color: var(--color-gray-900);
  margin-bottom: var(--space-3);
}

.case-card__quote {
  font-size: var(--text-base);
  font-style: italic;
  color: var(--color-gray-600);
  margin-bottom: var(--space-4);
  line-height: var(--leading-relaxed);
}

.case-card__stats {
  display: flex;
  gap: var(--space-6);
  margin-bottom: var(--space-4);
}

.case-card__stat {
  text-align: center;
}

.case-card__stat-value {
  font-size: var(--text-xl);
  font-weight: var(--font-bold);
  color: var(--color-primary);
}

.case-card__stat-label {
  font-size: var(--text-xs);
  color: var(--color-gray-500);
  text-transform: uppercase;
}

@media (min-width: 768px) {
  .case-studies__grid {
    grid-template-columns: repeat(3, 1fr);
  }
}

/* ==========================================================================
   Stats Section
   ========================================================================== */

.stats {
  background-color: var(--color-gray-50);
}

.stats__grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: var(--space-8);
}

.stats__item {
  text-align: center;
}

.stats__value {
  font-family: var(--font-heading);
  font-size: var(--text-4xl);
  font-weight: var(--font-bold);
  color: var(--color-primary);
  line-height: var(--leading-none);
  margin-bottom: var(--space-2);
}

.stats__label {
  font-size: var(--text-sm);
  color: var(--color-gray-600);
}

.stats__logos {
  margin-top: var(--space-12);
  padding-top: var(--space-12);
  border-top: 1px solid var(--color-gray-200);
}

@media (min-width: 768px) {
  .stats__grid {
    grid-template-columns: repeat(4, 1fr);
  }

  .stats__value {
    font-size: var(--text-5xl);
  }
}

/* ==========================================================================
   CTA Section
   ========================================================================== */

.cta-section {
  background: linear-gradient(135deg, var(--color-primary) 0%, var(--color-primary-dark) 100%);
  color: var(--color-white);
  text-align: center;
}

.cta-section__title {
  font-family: var(--font-heading);
  font-size: var(--text-3xl);
  font-weight: var(--font-bold);
  margin-bottom: var(--space-4);
}

.cta-section__subtitle {
  font-size: var(--text-lg);
  opacity: 0.9;
  margin-bottom: var(--space-8);
  max-width: 600px;
  margin-left: auto;
  margin-right: auto;
}

@media (min-width: 1024px) {
  .cta-section__title {
    font-size: var(--text-4xl);
  }
}

/* ==========================================================================
   Breadcrumb
   ========================================================================== */

.breadcrumb {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: var(--space-2);
  font-size: var(--text-sm);
  margin-bottom: var(--space-4);
}

.breadcrumb__link {
  color: var(--color-gray-500);
  text-decoration: none;
  transition: color var(--transition-fast);
}

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

.breadcrumb__separator {
  color: var(--color-gray-400);
}

.breadcrumb__current {
  color: var(--color-gray-900);
  font-weight: var(--font-medium);
}

/* Hero breadcrumb (white text) */
.hero .breadcrumb__link {
  color: rgba(255, 255, 255, 0.7);
}

.hero .breadcrumb__link:hover {
  color: var(--color-white);
}

.hero .breadcrumb__separator {
  color: rgba(255, 255, 255, 0.5);
}

.hero .breadcrumb__current {
  color: var(--color-white);
}

/* ==========================================================================
   Page Hero (Inner Pages)
   ========================================================================== */

.page-hero {
  padding-top: calc(var(--header-height-mobile) + var(--space-12));
  padding-bottom: var(--space-12);
  background: linear-gradient(135deg, var(--color-primary) 0%, var(--color-primary-dark) 100%);
  color: var(--color-white);
}

.page-hero__title {
  font-family: var(--font-heading);
  font-size: var(--text-4xl);
  font-weight: var(--font-bold);
  margin-bottom: var(--space-4);
}

.page-hero__subtitle {
  font-size: var(--text-lg);
  opacity: 0.9;
  max-width: 600px;
}

.page-hero__meta {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-4);
  margin-top: var(--space-6);
}

.page-hero__meta-item {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  font-size: var(--text-sm);
  opacity: 0.9;
}

@media (min-width: 768px) {
  .page-hero {
    padding-top: calc(var(--header-height) + var(--space-16));
    padding-bottom: var(--space-16);
  }

  .page-hero__title {
    font-size: var(--text-5xl);
  }
}

/* ==========================================================================
   Main Content Area
   ========================================================================== */

main {
  min-height: 50vh;
}

/* Skip link for accessibility */
.skip-link {
  position: absolute;
  top: -100%;
  left: 50%;
  transform: translateX(-50%);
  padding: var(--space-3) var(--space-6);
  background-color: var(--color-primary);
  color: var(--color-white);
  text-decoration: none;
  font-weight: var(--font-medium);
  border-radius: var(--radius-md);
  z-index: 9999;
  transition: top var(--transition-fast);
}

.skip-link:focus {
  top: var(--space-4);
}