/* 导航 */
.nav {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 100;
  background: var(--nav-bg);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border-color);
  transition: background 0.35s ease, border-color 0.35s ease, box-shadow 0.35s ease;
}

.nav.is-scrolled {
  background: var(--nav-bg-scrolled);
  box-shadow: 0 4px 24px rgba(0, 0, 0, 0.06);
}

body[data-theme="dark"] .nav.is-scrolled {
  box-shadow: 0 4px 24px rgba(0, 0, 0, 0.35);
}

.nav__inner {
  max-width: 80rem;
  margin: 0 auto;
  padding: 1rem 1.5rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
}

.nav__brand {
  display: flex;
  align-items: center;
  gap: 0.625rem;
  transition: transform 0.2s;
  flex-shrink: 0;
}

.nav__brand:hover {
  transform: scale(1.03);
}

.nav__brand-logo {
  width: 2.5rem;
  height: 2.5rem;
  border-radius: 0.625rem;
  object-fit: cover;
}

.nav__brand-name {
  font-size: 1.25rem;
  font-weight: 900;
  letter-spacing: -0.03em;
  color: var(--text-primary);
}

.nav__brand-accent {
  color: var(--brand);
}

.nav__brand--footer .nav__brand-name {
  color: var(--text-primary);
}

.nav__links {
  display: none;
  align-items: center;
  gap: 1.25rem;
}

@media (min-width: 1024px) {
  .nav__links {
    display: flex;
  }
}

.nav__link {
  font-size: 0.8125rem;
  font-weight: 500;
  letter-spacing: 0.02em;
  position: relative;
  transition: color 0.3s;
  color: var(--nav-text);
  white-space: nowrap;
}

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

.nav__link::after {
  content: "";
  position: absolute;
  bottom: -0.25rem;
  left: 0;
  width: 100%;
  height: 2px;
  background: var(--brand);
  transform: scaleX(0);
  transform-origin: left;
  transition: transform 0.3s var(--transition-spring);
}

.nav__link:hover::after {
  transform: scaleX(1);
}

.nav__right {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  flex-shrink: 0;
}

.theme-toggle {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 2.5rem;
  height: 2.5rem;
  border: 1px solid var(--border-color);
  border-radius: var(--radius-full);
  background: var(--card-bg);
  color: var(--text-primary);
  position: relative;
  z-index: 2;
  touch-action: manipulation;
  -webkit-tap-highlight-color: transparent;
  transition: background-color 0.3s, border-color 0.3s, transform 0.2s, color 0.3s;
}

.theme-toggle:hover {
  transform: scale(1.05);
  border-color: var(--brand);
  color: var(--brand);
}

body[data-theme="light"] .theme-icon-sun {
  display: none;
}

body[data-theme="light"] .theme-icon-moon {
  display: block;
}

body[data-theme="dark"] .theme-icon-moon {
  display: none;
}

body[data-theme="dark"] .theme-icon-sun {
  display: block;
}

.nav__cta {
  display: none;
  align-items: center;
  background: var(--brand);
  color: var(--white);
  padding: 0.625rem 1.25rem;
  border-radius: var(--radius-full);
  font-weight: 700;
  font-size: 0.8125rem;
  letter-spacing: 0.025em;
  position: relative;
  overflow: hidden;
  transition: transform 0.2s;
}

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

.nav__cta:hover {
  transform: scale(1.05);
}

.nav__cta-shimmer {
  position: absolute;
  inset: 0;
  background: linear-gradient(90deg, transparent, rgba(255, 255, 255, 0.25), transparent);
  animation: shimmer 3s infinite;
  animation-delay: 1s;
}

.nav__menu-toggle {
  display: block;
  padding: 0.5rem;
  color: var(--text-primary);
}

@media (min-width: 1024px) {
  .nav__menu-toggle {
    display: none;
  }
}

.nav__menu-toggle svg {
  width: 1.5rem;
  height: 1.5rem;
}

#nav-icon-close {
  display: none;
}

.nav__mobile-menu {
  display: none;
  background: var(--mobile-menu-bg);
  backdrop-filter: blur(12px);
  border-top: 1px solid var(--border-color);
  overflow: hidden;
}

.nav__mobile-menu.is-open {
  display: block;
}

.nav__mobile-menu-inner {
  padding: 1rem 1.5rem;
}

.nav__mobile-link {
  display: block;
  width: 100%;
  text-align: left;
  color: var(--mobile-menu-text);
  font-size: 1rem;
  font-weight: 500;
  padding: 0.5rem 0;
  transition: color 0.3s;
}

.nav__mobile-link:hover {
  color: var(--brand);
}

.nav__mobile-cta {
  display: block;
  width: 100%;
  text-align: center;
  background: var(--brand);
  color: var(--white);
  padding: 0.75rem 1.5rem;
  border-radius: var(--radius-full);
  font-weight: 700;
  font-size: 0.875rem;
  margin-top: 1rem;
}

/* Hero 徽章与标题 */
.badge {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  background: var(--badge-bg);
  color: var(--badge-text);
  padding: 0.375rem 0.875rem;
  border-radius: var(--radius-full);
  font-size: 0.75rem;
  letter-spacing: 0.05em;
  border: 1px solid var(--border-color);
}

.badge__dot {
  width: 0.5rem;
  height: 0.5rem;
  background: var(--brand);
  border-radius: 50%;
  animation: pulse-dot 2s ease-in-out infinite;
}

.hero-title {
  font-size: clamp(2.5rem, 7vw, 4rem);
  font-weight: 900;
  letter-spacing: -0.05em;
  line-height: 0.95;
  color: var(--text-primary);
}

.hero-title__accent {
  color: var(--brand);
}

.hero-desc {
  font-size: clamp(0.9375rem, 2vw, 1.125rem);
  color: var(--text-secondary);
  max-width: 32rem;
  padding-top: 0.75rem;
  line-height: 1.7;
}

/* 按钮 */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.75rem 1.5rem;
  border-radius: var(--radius-full);
  font-weight: 700;
  font-size: 0.875rem;
  letter-spacing: 0.025em;
  transition: transform 0.2s, background 0.3s, color 0.3s, border-color 0.3s;
  position: relative;
  overflow: hidden;
}

.btn:hover {
  transform: scale(1.02);
}

.btn:active {
  transform: scale(0.98);
}

.btn-primary {
  background: var(--brand);
  color: var(--white);
}

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

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

.btn-group {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
  padding-top: 1rem;
}

.feature-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
  padding-top: 1.25rem;
}

.feature-tag {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  font-size: 0.75rem;
  color: var(--text-secondary);
  padding: 0.375rem 0.75rem;
  border-radius: var(--radius-full);
  border: 1px solid var(--border-color);
  background: var(--card-bg);
}

.feature-tag__dot {
  width: 0.375rem;
  height: 0.375rem;
  background: var(--brand);
  border-radius: 50%;
}

.selling-points {
  margin: 0;
  padding: 0;
}

/* Hero 产品图 */
.hero-product {
  position: relative;
  display: flex;
  justify-content: center;
}

.hero-product__glow {
  position: absolute;
  inset: 0;
  background: var(--brand-glow);
  filter: blur(80px);
  border-radius: 50%;
  transform: scale(0.75);
  animation: pulse-glow 4s ease-in-out infinite;
}

.hero-product__img {
  position: relative;
  z-index: 10;
  max-width: 280px;
  border-radius: var(--radius-3xl);
  filter: drop-shadow(0 25px 25px rgba(0, 0, 0, 0.15));
}

/* 应用下载卡片 */
.app-download-card {
  display: flex;
  gap: 1.5rem;
  align-items: center;
  border: 2px solid var(--border-color);
  border-radius: var(--radius-3xl);
  padding: 2rem;
  background: var(--card-bg);
  box-shadow: var(--shadow-xl);
  max-width: 42rem;
  margin: 0 auto;
  transition: transform 0.3s;
}

.app-download-card:hover {
  transform: translateY(-4px);
}

.app-icon {
  width: 4.5rem;
  height: 4.5rem;
  object-fit: cover;
  border-radius: var(--radius-xl);
  border: 1px solid var(--border-color);
  flex-shrink: 0;
}

.app-download-info h3 {
  font-size: 1.5rem;
  font-weight: 900;
  letter-spacing: -0.03em;
  margin-bottom: 0.375rem;
  color: var(--text-primary);
}

.app-download-desc {
  font-size: 0.8125rem;
  color: var(--text-secondary);
  margin-bottom: 1rem;
}

.download-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
}

.download-btn {
  min-width: 8rem;
}

/* 截图展示卡片 */
.image-card {
  margin: 0;
  transition: transform 0.3s;
}

.image-card:hover {
  transform: translateY(-6px);
}

.image-card__inner {
  border-radius: var(--radius-2xl);
  padding: 1rem;
  border: 2px solid var(--border-color);
  background: var(--card-bg);
  box-shadow: var(--shadow-xl);
  overflow: hidden;
}

.image-card img {
  width: 100%;
  max-height: 560px;
  object-fit: contain;
  border-radius: var(--radius-xl);
  background: var(--bg-color);
}

.image-card figcaption {
  margin-top: 0.75rem;
  color: var(--text-muted);
  font-size: 0.8125rem;
  text-align: center;
}

/* 页脚 */
.footer-cta-title {
  font-size: clamp(2rem, 5vw, 3.25rem);
  font-weight: 900;
  color: var(--text-primary);
  letter-spacing: -0.05em;
  line-height: 0.95;
  text-align: center;
  margin-bottom: 1.5rem;
}

.footer-cta-title__accent {
  color: var(--brand);
}

.footer-desc {
  text-align: center;
  color: var(--text-secondary);
  font-size: 0.8125rem;
  max-width: 40rem;
  margin: 0 auto 2.5rem;
  line-height: 1.7;
}

.footer-bottom {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.75rem;
  padding-top: 1.5rem;
  border-top: 1px solid var(--border-color);
}

@media (min-width: 768px) {
  .footer-bottom {
    flex-direction: row;
    justify-content: space-between;
  }
}

.footer-bottom__copy {
  color: var(--text-muted);
  font-size: 0.75rem;
}

@media (max-width: 760px) {
  .app-download-card {
    flex-direction: column;
    align-items: flex-start;
  }
}

@media (max-width: 980px) {
  .nav__inner {
    flex-wrap: nowrap;
  }
}