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

:root {
  --color-primary: #0071e3;
  --color-primary-hover: #0077ed;
  --color-text: #1d1d1f;
  --color-text-secondary: #6e6e73;
  --color-bg: #ffffff;
  --color-bg-alt: #f5f5f7;
  --color-border: #d2d2d7;
  --font-stack: -apple-system, BlinkMacSystemFont, "PingFang SC", "Helvetica Neue", "Microsoft YaHei", sans-serif;
  --max-width: 980px;
}

html {
  font-size: 16px;
  scroll-behavior: smooth;
}

body {
  font-family: var(--font-stack);
  color: var(--color-text);
  background: var(--color-bg);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

a {
  color: var(--color-primary);
  text-decoration: none;
}

a:hover {
  text-decoration: underline;
}

.container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 24px;
}

/* ── Header ── */

.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(255, 255, 255, 0.8);
  backdrop-filter: saturate(180%) blur(20px);
  -webkit-backdrop-filter: saturate(180%) blur(20px);
  border-bottom: 1px solid var(--color-border);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 52px;
}

.logo {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 1.125rem;
  font-weight: 600;
  color: var(--color-text);
  text-decoration: none;
}

.logo:hover {
  text-decoration: none;
}

.logo-icon {
  width: 28px;
  height: 28px;
  background: linear-gradient(135deg, var(--color-primary), #34c759);
  border-radius: 7px;
  display: flex;
  align-items: center;
  justify-content: center;
  color: #fff;
  font-size: 14px;
  font-weight: 700;
}

.header-nav {
  display: flex;
  align-items: center;
  gap: 24px;
}

.header-nav a {
  font-size: 0.875rem;
  color: var(--color-text-secondary);
}

.header-nav a:hover {
  color: var(--color-text);
  text-decoration: none;
}

.lang-switch {
  font-size: 0.8125rem;
  padding: 4px 12px;
  border: 1px solid var(--color-border);
  border-radius: 16px;
  color: var(--color-text-secondary);
}

.lang-switch:hover {
  background: var(--color-bg-alt);
  text-decoration: none;
  color: var(--color-text);
}

/* ── Hero ── */

.hero {
  text-align: center;
  padding: 100px 24px 80px;
}

.hero-badge {
  display: inline-block;
  font-size: 0.8125rem;
  font-weight: 500;
  color: var(--color-primary);
  background: rgba(0, 113, 227, 0.08);
  padding: 6px 16px;
  border-radius: 20px;
  margin-bottom: 24px;
}

.hero h1 {
  font-size: 3rem;
  font-weight: 700;
  line-height: 1.15;
  letter-spacing: -0.02em;
  margin-bottom: 20px;
}

.hero h1 span {
  background: linear-gradient(135deg, var(--color-primary), #34c759);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.hero-subtitle {
  font-size: 1.25rem;
  color: var(--color-text-secondary);
  max-width: 600px;
  margin: 0 auto 40px;
  line-height: 1.5;
}

.hero-actions {
  display: flex;
  gap: 16px;
  justify-content: center;
  flex-wrap: wrap;
}

.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 14px 28px;
  border-radius: 12px;
  font-size: 1rem;
  font-weight: 500;
  transition: all 0.2s ease;
  cursor: pointer;
  border: none;
}

.btn-primary {
  background: var(--color-primary);
  color: #fff;
}

.btn-primary:hover {
  background: var(--color-primary-hover);
  text-decoration: none;
  transform: scale(1.02);
}

.btn-secondary {
  background: var(--color-bg-alt);
  color: var(--color-text);
  border: 1px solid var(--color-border);
}

.btn-secondary:hover {
  background: #ebebed;
  text-decoration: none;
  transform: scale(1.02);
}

.btn-icon {
  font-size: 1.125rem;
}

/* ── Features ── */

.features {
  padding: 80px 0;
  background: var(--color-bg-alt);
}

.section-title {
  text-align: center;
  margin-bottom: 56px;
}

.section-title h2 {
  font-size: 2rem;
  font-weight: 700;
  letter-spacing: -0.01em;
  margin-bottom: 12px;
}

.section-title p {
  font-size: 1.0625rem;
  color: var(--color-text-secondary);
}

.features-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 20px;
}

.feature-card {
  background: var(--color-bg);
  border-radius: 20px;
  padding: 40px 32px;
  transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.feature-card:hover {
  transform: translateY(-4px);
  box-shadow: 0 8px 30px rgba(0, 0, 0, 0.08);
}

.feature-icon {
  width: 48px;
  height: 48px;
  border-radius: 12px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 24px;
  margin-bottom: 20px;
}

.feature-icon-voice {
  background: rgba(0, 113, 227, 0.1);
}

.feature-icon-ai {
  background: rgba(52, 199, 89, 0.1);
}

.feature-icon-edit {
  background: rgba(255, 149, 0, 0.1);
}

.feature-icon-memory {
  background: rgba(175, 82, 222, 0.1);
}

.feature-card h3 {
  font-size: 1.25rem;
  font-weight: 600;
  margin-bottom: 10px;
}

.feature-card p {
  font-size: 0.9375rem;
  color: var(--color-text-secondary);
  line-height: 1.6;
}

/* ── About ── */

.about {
  padding: 80px 0;
}

.about-content {
  display: grid;
  grid-template-columns: 2fr 1fr;
  gap: 48px;
  align-items: start;
}

.about-text p {
  font-size: 1rem;
  color: var(--color-text-secondary);
  line-height: 1.8;
  margin-bottom: 16px;
}

.about-text p:last-child {
  margin-bottom: 0;
}

.about-text strong {
  color: var(--color-text);
}

.about-highlights {
  display: flex;
  flex-direction: column;
  gap: 24px;
  padding-top: 4px;
}

.highlight-item {
  text-align: center;
  padding: 24px;
  background: var(--color-bg-alt);
  border-radius: 16px;
}

.highlight-number {
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--color-primary);
  margin-bottom: 4px;
}

.highlight-label {
  font-size: 0.8125rem;
  color: var(--color-text-secondary);
}

/* ── Product ── */

.product-intro {
  text-align: center;
  max-width: 700px;
  margin: -24px auto 48px;
}

.product-intro p {
  font-size: 1.0625rem;
  color: var(--color-text-secondary);
  line-height: 1.7;
}

.product-download {
  text-align: center;
  margin-top: 48px;
}

/* ── Contact ── */

.contact {
  padding: 80px 0;
}

.contact-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

.contact-card {
  text-align: center;
  padding: 40px 24px;
  background: var(--color-bg-alt);
  border-radius: 20px;
}

.contact-icon {
  font-size: 32px;
  margin-bottom: 16px;
}

.contact-card h3 {
  font-size: 1.0625rem;
  font-weight: 600;
  margin-bottom: 12px;
}

.contact-card p {
  font-size: 0.9375rem;
  color: var(--color-text-secondary);
  line-height: 1.7;
}

/* ── Download ── */

.download {
  padding: 100px 0;
  text-align: center;
}

.download h2 {
  font-size: 2.25rem;
  font-weight: 700;
  margin-bottom: 16px;
}

.download-desc {
  font-size: 1.0625rem;
  color: var(--color-text-secondary);
  margin-bottom: 40px;
}

.download-info {
  margin-top: 20px;
  font-size: 0.8125rem;
  color: var(--color-text-secondary);
}

/* ── Footer ── */

.site-footer {
  background: var(--color-text);
  color: rgba(255, 255, 255, 0.7);
  padding: 40px 0;
}

.footer-inner {
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 16px;
}

.footer-left {
  font-size: 0.8125rem;
  line-height: 1.8;
}

.footer-left a {
  color: rgba(255, 255, 255, 0.7);
}

.footer-left a:hover {
  color: #fff;
}

.footer-right {
  display: flex;
  gap: 24px;
  font-size: 0.8125rem;
}

.footer-right a {
  color: rgba(255, 255, 255, 0.5);
}

.footer-right a:hover {
  color: #fff;
}

/* ── Responsive ── */

@media (max-width: 768px) {
  .hero {
    padding: 64px 20px 56px;
  }

  .hero h1 {
    font-size: 2rem;
  }

  .hero-subtitle {
    font-size: 1.0625rem;
  }

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

  .about-content {
    grid-template-columns: 1fr;
    gap: 32px;
  }

  .about-highlights {
    flex-direction: row;
  }

  .highlight-item {
    flex: 1;
  }

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

  .feature-card {
    padding: 32px 24px;
  }

  .download h2 {
    font-size: 1.75rem;
  }

  .footer-inner {
    flex-direction: column;
    text-align: center;
  }

  .footer-right {
    justify-content: center;
  }
}

@media (max-width: 480px) {
  .header-nav {
    gap: 16px;
  }

  .hero h1 {
    font-size: 1.75rem;
  }

  .hero-actions {
    flex-direction: column;
    align-items: center;
  }

  .btn {
    width: 100%;
    max-width: 280px;
    justify-content: center;
  }
}