:root {
  --apple-blue: #007aff;
  --apple-blue-dark: #0056cc;
  --apple-gray: #86868b;
  --apple-gray-light: #f5f5f7;
  --apple-black: #1d1d1f;
  --apple-white: #ffffff;
  --apple-bg: #fbfbfd;
  --apple-bg-secondary: #f5f5f7;
  --border-light: rgba(0, 0, 0, 0.04);
  --border-medium: rgba(0, 0, 0, 0.08);
  --shadow-subtle: 0 4px 24px rgba(0, 0, 0, 0.06);
  --shadow-card: 0 2px 8px rgba(0, 0, 0, 0.04);
  --shadow-elevated: 0 8px 32px rgba(0, 0, 0, 0.08);
  --radius-small: 8px;
  --radius-medium: 12px;
  --radius-large: 18px;
  --radius-xl: 24px;
  --transition-fast: 0.2s cubic-bezier(0.65, 0, 0.35, 1);
  --transition-smooth: 0.4s cubic-bezier(0.65, 0, 0.35, 1);
  --font-stack:
    -apple-system, BlinkMacSystemFont, 'SF Pro Display', 'SF Pro Text',
    'Helvetica Neue', 'PingFang SC', 'Microsoft YaHei', sans-serif;
}

* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  font-family: var(--font-stack);
  font-size: 17px;
  line-height: 1.47059;
  letter-spacing: -0.022em;
  color: var(--apple-black);
  background: var(--apple-bg);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  overflow-x: hidden;
}

a {
  color: inherit;
  text-decoration: none;
}

img {
  max-width: 100%;
  height: auto;
}

.navbar {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: 48px;
  background: rgba(251, 251, 253, 0.8);
  backdrop-filter: saturate(180%) blur(20px);
  -webkit-backdrop-filter: saturate(180%) blur(20px);
  z-index: 9999;
  transition: all var(--transition-fast);
}

.navbar.scrolled {
  background: rgba(251, 251, 253, 0.95);
  box-shadow: 0 1px 0 rgba(0, 0, 0, 0.05);
}

.nav-container {
  max-width: 980px;
  margin: 0 auto;
  padding: 0 20px;
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.nav-logo {
  font-size: 21px;
  font-weight: 600;
  color: var(--apple-black);
  transition: opacity var(--transition-fast);
}

.nav-logo:hover {
  opacity: 0.65;
}

.nav-menu {
  display: flex;
  gap: 28px;
}

.nav-link {
  font-size: 12px;
  font-weight: 400;
  color: var(--apple-black);
  opacity: 0.8;
  transition: all var(--transition-fast);
}

.nav-link:hover {
  opacity: 0.45;
}

.hero-banner {
  position: relative;
  width: 100%;
  height: 100vh;
  overflow: hidden;
  background: var(--apple-black);
}

.hero-banner-image {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.hero-banner-overlay {
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: linear-gradient(
    to bottom,
    rgba(0, 0, 0, 0.5) 0%,
    rgba(0, 0, 0, 0.3) 50%,
    rgba(0, 0, 0, 0.6) 100%
  );
  display: flex;
  align-items: center;
  justify-content: center;
  padding-top: 48px;
}

.hero-banner-content {
  text-align: center;
  color: white;
  max-width: 700px;
  padding: 0 20px;
}

.hero-badge {
  display: inline-block;
  padding: 6px 16px;
  background: rgba(255, 255, 255, 0.15);
  backdrop-filter: blur(10px);
  border-radius: 980px;
  font-size: 13px;
  font-weight: 600;
  letter-spacing: 0.08em;
  color: #fff;
  margin-bottom: 32px;
  text-transform: uppercase;
  border: 1px solid rgba(255, 255, 255, 0.2);
}

.hero-stat {
  gap: 12px;
  margin-bottom: 16px;
}

.hero-stat-number {
  font-weight: 700;
  line-height: 1;
  color: #409cff;
  text-shadow: 0 2px 20px rgba(0, 0, 0, 0.3);
  font-size: 24px;
}

.hero-stat-label {
  font-size: 24px;
  font-weight: 500;
  color: rgba(255, 255, 255, 0.9);
  text-shadow: 0 1px 10px rgba(0, 0, 0, 0.3);
  background: gray;
}

.hero-title {
  font-size: clamp(42px, 6vw, 56px);
  font-weight: 700;
  line-height: 1.07143;
  letter-spacing: -0.005em;
  color: white;
  margin-bottom: 24px;
  text-shadow: 0 2px 20px rgba(0, 0, 0, 0.3);
}

.hero-subtitle {
  font-size: 21px;
  line-height: 1.33341;
  font-weight: 400;
  letter-spacing: 0.009em;
  color: rgba(255, 255, 255, 0.85);
  margin-bottom: 56px;
  text-shadow: 0 1px 10px rgba(0, 0, 0, 0.3);
}

.hero-actions {
  display: flex;
  gap: 14px;
  justify-content: center;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 14px 28px;
  border-radius: 980px;
  font-size: 15px;
  font-weight: 600;
  letter-spacing: 0.016em;
  transition: all var(--transition-fast);
}

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

.btn-primary:hover {
  background: var(--apple-blue-dark);
  transform: scale(1.02);
}

.btn-secondary {
  background: white;
  color: var(--apple-black);
}

.btn-secondary:hover {
  background: #f5f5f5;
  transform: scale(1.02);
}

.features {
  padding: 100px 20px;
  background: var(--apple-bg-secondary);
}

.features-container {
  max-width: 980px;
  margin: 0 auto;
}

.feature-header {
  text-align: center;
  margin-bottom: 60px;
}

.feature-header h2 {
  font-size: clamp(32px, 5vw, 40px);
  font-weight: 700;
  color: var(--apple-black);
  margin-bottom: 8px;
}

.feature-header p {
  font-size: 19px;
  color: var(--apple-gray);
}

.feature-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 20px;
}

.feature-card {
  padding: 32px 24px;
  background: white;
  border-radius: var(--radius-large);
  box-shadow: var(--shadow-card);
  transition: all var(--transition-smooth);
  opacity: 0;
  transform: translateY(20px);
}

.feature-card.visible {
  opacity: 1;
  transform: translateY(0);
}

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

.feature-icon {
  font-size: 32px;
  margin-bottom: 16px;
  color: var(--apple-blue);
}

.feature-card h3 {
  font-size: 17px;
  font-weight: 600;
  color: var(--apple-black);
  margin-bottom: 8px;
}

.feature-card p {
  font-size: 14px;
  line-height: 1.5;
  color: var(--apple-gray);
}

.showcase {
  padding: 100px 20px;
  background: white;
}

.showcase-container {
  max-width: 980px;
  margin: 0 auto;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 80px;
  align-items: center;
}

.showcase-image img {
  width: 100%;
  border-radius: var(--radius-large);
  box-shadow: var(--shadow-subtle);
}

.showcase-content h2 {
  font-size: clamp(28px, 4vw, 36px);
  font-weight: 700;
  color: var(--apple-black);
  margin-bottom: 24px;
}

.feature-list {
  list-style: none;
}

.feature-list li {
  position: relative;
  padding-left: 28px;
  margin-bottom: 14px;
  font-size: 17px;
  color: var(--apple-gray);
}

.feature-list li::before {
  content: '✓';
  position: absolute;
  left: 0;
  color: var(--apple-blue);
  font-weight: 600;
}

.download-section {
  padding: 100px 20px;
  background: var(--apple-bg-secondary);
}

.download-container {
  max-width: 980px;
  margin: 0 auto;
  text-align: center;
}

.download-container h2 {
  font-size: clamp(32px, 5vw, 40px);
  font-weight: 700;
  color: var(--apple-black);
  margin-bottom: 8px;
}

.download-container > p {
  font-size: 19px;
  color: var(--apple-gray);
  margin-bottom: 50px;
}

.download-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
}

.download-card {
  padding: 40px 24px;
  background: white;
  border-radius: var(--radius-large);
  box-shadow: var(--shadow-card);
  transition: all var(--transition-smooth);
}

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

.browser-icon {
  width: 64px;
  height: 64px;
  margin: 0 auto 20px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 36px;
  font-weight: 300;
  background: var(--apple-bg-secondary);
  border-radius: 14px;
  color: var(--apple-blue);
}

.download-card h3 {
  font-size: 19px;
  font-weight: 600;
  margin-bottom: 6px;
}

.download-card p {
  font-size: 14px;
  color: var(--apple-gray);
  margin-bottom: 20px;
}

.btn-download {
  display: inline-block;
  padding: 10px 20px;
  background: var(--apple-blue);
  color: white;
  border-radius: 980px;
  font-size: 14px;
  font-weight: 500;
  transition: all var(--transition-fast);
}

.btn-download:hover {
  background: var(--apple-blue-dark);
}

.install-guide {
  padding: 100px 20px;
  background: white;
}

.install-container {
  max-width: 980px;
  margin: 0 auto;
  text-align: center;
}

.install-container h2 {
  font-size: clamp(32px, 5vw, 40px);
  font-weight: 700;
  color: var(--apple-black);
  margin-bottom: 8px;
}

.install-container > p {
  font-size: 19px;
  color: var(--apple-gray);
  margin-bottom: 50px;
}

.install-steps {
  max-width: 800px;
  margin: 0 auto;
  border-radius: var(--radius-large);
  overflow: hidden;
  box-shadow: var(--shadow-subtle);
}

.install-image {
  width: 100%;
  display: block;
}

.faq {
  padding: 100px 20px;
  background: var(--apple-bg-secondary);
}

.faq-container {
  max-width: 680px;
  margin: 0 auto;
}

.faq-container h2 {
  font-size: clamp(32px, 5vw, 40px);
  font-weight: 700;
  color: var(--apple-black);
  text-align: center;
  margin-bottom: 50px;
}

.faq-list {
  display: flex;
  flex-direction: column;
  gap: 1px;
  background: var(--border-medium);
  border-radius: var(--radius-large);
  overflow: hidden;
}

.faq-item {
  background: white;
  padding: 20px 24px;
}

.faq-item summary {
  font-size: 17px;
  font-weight: 500;
  cursor: pointer;
  list-style: none;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.faq-item summary::-webkit-details-marker {
  display: none;
}

.faq-item summary::after {
  content: '+';
  font-size: 20px;
  color: var(--apple-gray);
  transition: transform var(--transition-fast);
}

.faq-item[open] summary::after {
  transform: rotate(45deg);
}

.faq-item p {
  font-size: 15px;
  color: var(--apple-gray);
  line-height: 1.5;
  margin-top: 12px;
}

.footer {
  padding: 60px 20px 40px;
  background: white;
}

.footer-container {
  max-width: 980px;
  margin: 0 auto;
}

.footer-top {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding-bottom: 30px;
  border-bottom: 1px solid var(--border-light);
}

.footer-logo {
  font-size: 21px;
  font-weight: 600;
  margin-bottom: 4px;
}

.footer-brand p {
  font-size: 14px;
  color: var(--apple-gray);
}

.footer-link {
  display: inline-flex;
  align-items: center;
  padding: 10px 18px;
  background: var(--apple-blue);
  color: white;
  border-radius: 980px;
  font-size: 14px;
  font-weight: 500;
  transition: all var(--transition-fast);
}

.footer-link:hover {
  background: var(--apple-blue-dark);
}

.footer-bottom {
  padding-top: 30px;
  display: flex;
  justify-content: space-between;
  font-size: 12px;
  color: var(--apple-gray);
}

.footer-bottom a {
  text-decoration: underline;
}

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

  .hero-banner {
    height: auto;
    min-height: 100vh;
    padding: 80px 20px 60px;
  }

  .hero-banner-image {
    object-fit: cover;
  }

  .hero-banner-overlay {
    align-items: flex-end;
    padding-bottom: 40px;
  }

  .hero-badge {
    font-size: 11px;
    padding: 4px 12px;
    margin-bottom: 16px;
  }

  .hero-stat {
    margin-bottom: 8px;
  }

  .hero-stat-number {
    font-size: 18px;
  }

  .hero-stat-label {
    font-size: 18px;
  }

  .hero-title {
    font-size: 32px;
    margin-bottom: 16px;
  }

  .hero-subtitle {
    font-size: 15px;
    margin-bottom: 24px;
  }

  .hero-actions {
    flex-direction: column;
    gap: 12px;
  }

  .btn {
    width: 100%;
    padding: 12px 20px;
    font-size: 15px;
  }

  .feature-grid {
    grid-template-columns: 1fr;
  }

  .showcase-container {
    grid-template-columns: 1fr;
    gap: 40px;
  }

  .download-grid {
    grid-template-columns: 1fr;
  }

  .footer-top {
    flex-direction: column;
    gap: 30px;
    text-align: center;
  }

  .footer-bottom {
    flex-direction: column;
    gap: 10px;
    text-align: center;
  }

  .logo::before {
    display: none;
  }
}