.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--spacing-sm);
  min-height: 44px;
  min-width: 44px;
  padding: var(--spacing-sm) var(--spacing-lg);
  font-size: var(--font-size-base);
  font-weight: var(--font-weight-semibold);
  border-radius: var(--radius-md);
  transition: all var(--transition-normal);
  cursor: pointer;
  text-decoration: none;
  line-height: 1;
}

.btn-primary {
  background-color: var(--color-accent);
  color: var(--color-text-white);
  border: 2px solid var(--color-accent);
}

.btn-primary:hover {
  background-color: var(--color-accent-hover);
  border-color: var(--color-accent-hover);
  color: var(--color-text-white);
  transform: translateY(-1px);
  box-shadow: var(--shadow-md);
}

.btn-primary:active {
  transform: translateY(0) scale(0.96);
}

.btn-secondary {
  background-color: transparent;
  color: var(--color-accent);
  border: 2px solid var(--color-accent);
}

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

.btn-secondary:active {
  transform: translateY(0) scale(0.96);
}

.btn-lg {
  padding: var(--spacing-md) var(--spacing-xl);
  font-size: var(--font-size-lg);
  min-height: 52px;
}

.nav-bar {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  height: var(--nav-height);
  background-color: transparent;
  transition: background-color var(--transition-normal), box-shadow var(--transition-normal);
}

.nav-bar.is-scrolled {
  background-color: rgba(26, 26, 46, 0.92);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  box-shadow: 0 2px 20px rgba(0, 0, 0, 0.15);
}

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

.nav-logo {
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
  color: var(--color-text-white);
  font-size: var(--font-size-xl);
  font-weight: var(--font-weight-bold);
  text-decoration: none;
}

.nav-logo svg,
.nav-logo-img {
  width: 32px;
  height: 32px;
}

.nav-links {
  display: none;
  gap: var(--spacing-lg);
}

@media (min-width: 768px) {
  .nav-links {
    display: flex;
  }
}

.nav-link {
  color: var(--color-text-white-light);
  font-size: var(--font-size-sm);
  font-weight: var(--font-weight-medium);
  transition: color var(--transition-fast);
  text-decoration: none;
}

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

.hamburger-btn {
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  width: 44px;
  height: 44px;
  gap: 5px;
  cursor: pointer;
}

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

.hamburger-line {
  width: 22px;
  height: 2px;
  background-color: var(--color-text-white);
  border-radius: 2px;
  transition: all var(--transition-normal);
  transform-origin: center;
}

.hamburger-btn[aria-expanded="true"] .hamburger-line:nth-child(1) {
  transform: translateY(7px) rotate(45deg);
}

.hamburger-btn[aria-expanded="true"] .hamburger-line:nth-child(2) {
  opacity: 0;
}

.hamburger-btn[aria-expanded="true"] .hamburger-line:nth-child(3) {
  transform: translateY(-7px) rotate(-45deg);
}

.mobile-menu-overlay {
  position: fixed;
  inset: 0;
  background-color: rgba(0, 0, 0, 0.5);
  z-index: 1001;
  opacity: 0;
  visibility: hidden;
  transition: opacity var(--transition-normal), visibility var(--transition-normal);
}

.mobile-menu-overlay.is-visible {
  opacity: 1;
  visibility: visible;
}

.mobile-menu {
  position: fixed;
  top: 0;
  right: 0;
  bottom: 0;
  width: 280px;
  max-width: 80vw;
  background-color: var(--color-bg-dark);
  z-index: 1002;
  transform: translateX(100%);
  transition: transform var(--transition-normal);
  padding: var(--spacing-3xl) var(--spacing-xl);
  display: flex;
  flex-direction: column;
  gap: var(--spacing-lg);
}

.mobile-menu.is-open {
  transform: translateX(0);
}

.mobile-menu-link {
  color: var(--color-text-white-light);
  font-size: var(--font-size-lg);
  font-weight: var(--font-weight-medium);
  padding: var(--spacing-md) 0;
  border-bottom: 1px solid var(--color-primary-light);
  transition: color var(--transition-fast);
  text-decoration: none;
  display: block;
}

.mobile-menu-link:hover {
  color: var(--color-text-white);
}

.section-hero {
  min-height: 80vh;
  background-color: var(--color-bg-dark);
  background-image: linear-gradient(135deg, var(--color-bg-dark) 0%, var(--color-secondary) 100%);
  display: flex;
  align-items: center;
  justify-content: center;
  text-align: center;
  padding-top: var(--nav-height);
  position: relative;
  overflow: hidden;
}

.hero-content {
  position: relative;
  z-index: 1;
}

.hero-logo {
  width: 80px;
  height: 80px;
  margin: 0 auto var(--spacing-lg);
}

.hero-logo img {
  width: 100%;
  height: 100%;
  object-fit: contain;
}

@media (min-width: 768px) {
  .hero-logo {
    width: 100px;
    height: 100px;
  }
}

.hero-title {
  font-size: var(--font-size-4xl);
  font-weight: var(--font-weight-bold);
  color: var(--color-text-white);
  margin-bottom: var(--spacing-md);
  line-height: var(--line-height-tight);
}

@media (min-width: 768px) {
  .hero-title {
    font-size: var(--font-size-5xl);
  }
}

.hero-slogan {
  font-size: var(--font-size-lg);
  color: var(--color-text-white-light);
  margin-bottom: var(--spacing-2xl);
  line-height: var(--line-height-relaxed);
  max-width: 500px;
  margin-left: auto;
  margin-right: auto;
}

@media (min-width: 768px) {
  .hero-slogan {
    font-size: var(--font-size-xl);
  }
}

.hero-buttons {
  display: flex;
  gap: var(--spacing-md);
  justify-content: center;
  flex-wrap: wrap;
}

.section-product {
  background-color: var(--color-bg);
}

.product-text h2 {
  font-size: var(--font-size-2xl);
  font-weight: var(--font-weight-bold);
  margin-bottom: var(--spacing-md);
}

@media (min-width: 768px) {
  .product-text h2 {
    font-size: var(--font-size-3xl);
  }
}

.product-text p {
  color: var(--color-text-light);
  margin-bottom: var(--spacing-lg);
  line-height: var(--line-height-relaxed);
}

.product-highlights {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-sm);
}

.product-highlight-item {
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
  color: var(--color-text);
  font-weight: var(--font-weight-medium);
}

.product-highlight-item svg {
  width: 20px;
  height: 20px;
  color: var(--color-accent);
  flex-shrink: 0;
}

.product-screenshot {
  border-radius: var(--radius-lg);
  overflow: hidden;
  box-shadow: var(--shadow-lg);
}

.product-screenshot img {
  width: 100%;
  height: auto;
}

.section-features {
  background-color: var(--color-bg-light);
}

.feature-card {
  background-color: var(--color-bg);
  border-radius: var(--radius-lg);
  padding: var(--spacing-xl);
  box-shadow: var(--shadow-sm);
  transition: transform var(--transition-normal), box-shadow var(--transition-normal);
  text-align: center;
}

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

.feature-icon {
  width: 56px;
  height: 56px;
  margin: 0 auto var(--spacing-md);
  background-color: var(--color-accent-light);
  border-radius: var(--radius-full);
  display: flex;
  align-items: center;
  justify-content: center;
}

.feature-icon svg {
  width: 28px;
  height: 28px;
  color: var(--color-accent);
}

.feature-title {
  font-size: var(--font-size-lg);
  font-weight: var(--font-weight-semibold);
  margin-bottom: var(--spacing-sm);
}

.feature-desc {
  font-size: var(--font-size-sm);
  color: var(--color-text-light);
  line-height: var(--line-height-relaxed);
}

.section-download {
  background-color: var(--color-bg-dark);
  background-image: linear-gradient(135deg, var(--color-secondary) 0%, var(--color-bg-dark) 100%);
  text-align: center;
}

.section-download .section-title {
  color: var(--color-text-white);
}

.section-download .section-subtitle {
  color: var(--color-text-white-light);
}

.download-buttons {
  display: flex;
  gap: var(--spacing-md);
  justify-content: center;
  flex-wrap: wrap;
  margin-bottom: var(--spacing-xl);
}

.download-btn {
  display: inline-flex;
  align-items: center;
  gap: var(--spacing-sm);
  padding: var(--spacing-md) var(--spacing-xl);
  background-color: var(--color-text-white);
  color: var(--color-bg-dark);
  font-size: var(--font-size-base);
  font-weight: var(--font-weight-semibold);
  border-radius: var(--radius-md);
  transition: all var(--transition-normal);
  text-decoration: none;
  min-height: 52px;
}

.download-btn:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
  color: var(--color-bg-dark);
}

.download-btn:active {
  transform: translateY(0) scale(0.96);
}

.download-btn svg {
  width: 24px;
  height: 24px;
}

.download-qr {
  display: none;
  flex-direction: column;
  align-items: center;
  gap: var(--spacing-sm);
}

@media (min-width: 768px) {
  .download-qr {
    display: flex;
  }
}

.download-qr img {
  width: 160px;
  height: 160px;
  border-radius: var(--radius-sm);
  background-color: var(--color-text-white);
  padding: var(--spacing-sm);
}

.download-qr span {
  color: var(--color-text-white-light);
  font-size: var(--font-size-sm);
}

.download-version {
  color: var(--color-text-white-light);
  font-size: var(--font-size-sm);
  margin-top: var(--spacing-md);
}

.section-company {
  background-color: var(--color-bg);
  text-align: center;
}

.company-name {
  font-size: var(--font-size-xl);
  font-weight: var(--font-weight-semibold);
  margin-bottom: var(--spacing-md);
}

.company-desc {
  color: var(--color-text-light);
  max-width: 600px;
  margin: 0 auto var(--spacing-lg);
  line-height: var(--line-height-relaxed);
}

.company-email {
  display: inline-flex;
  align-items: center;
  gap: var(--spacing-sm);
  color: var(--color-accent);
  font-weight: var(--font-weight-medium);
}

.company-email svg {
  width: 18px;
  height: 18px;
}

.section-footer {
  background-color: var(--color-bg-light);
  text-align: center;
  padding: var(--spacing-xl) 0;
}

.footer-copyright {
  font-size: var(--font-size-sm);
  color: var(--color-text-light);
  margin-bottom: var(--spacing-sm);
}

.footer-icp {
  font-size: var(--font-size-sm);
  color: var(--color-text-light);
}

.footer-icp a {
  color: var(--color-text-light);
  text-decoration: none;
}

.footer-icp a:hover {
  color: var(--color-accent);
}

.back-to-top {
  position: fixed;
  right: 24px;
  bottom: 24px;
  width: 44px;
  height: 44px;
  border-radius: var(--radius-full);
  background-color: var(--color-accent);
  color: var(--color-text-white);
  display: flex;
  align-items: center;
  justify-content: center;
  box-shadow: var(--shadow-md);
  transition: opacity var(--transition-normal), transform var(--transition-normal);
  z-index: 900;
  opacity: 0;
  transform: translateY(10px);
  pointer-events: none;
}

@media (min-width: 768px) {
  .back-to-top {
    width: 48px;
    height: 48px;
  }
}

.back-to-top.is-visible {
  opacity: 1;
  transform: translateY(0);
  pointer-events: auto;
}

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

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