:root {
  --bg: #ffffff;
  --bg-soft: #f6faf8;
  --bg-accent: #eff8f4;
  --card: #ffffff;
  --text: #102331;
  --muted: #637381;
  --line: #e5edf0;
  --primary: #16b26b;
  --primary-dark: #11985b;
  --secondary: #eef7f2;
  --shadow: 0 16px 40px rgba(20, 53, 74, 0.08);
  --radius: 22px;
  --container: 1160px;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  font-family: "Segoe UI", "PingFang SC", "Microsoft YaHei", sans-serif;
  color: var(--text);
  background: linear-gradient(180deg, #ffffff 0%, #fbfefd 100%);
  line-height: 1.6;
}

img {
  display: block;
  max-width: 100%;
}

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

button {
  font: inherit;
}

.container {
  width: min(var(--container), calc(100% - 32px));
  margin: 0 auto;
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 20;
  background: rgba(255, 255, 255, 0.92);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--line);
}

.site-header.is-scrolled {
  background: rgba(255, 255, 255, 0.98);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  min-height: 76px;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  font-weight: 700;
  letter-spacing: 0.02em;
}

.brand span {
  white-space: nowrap;
}

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

.site-nav a,
.footer-links a {
  color: var(--muted);
  transition: color 0.2s ease;
}

.site-nav a:hover,
.footer-links a:hover {
  color: var(--text);
}

.menu-toggle {
  display: none;
  padding: 10px 14px;
  color: var(--text);
  border: 1px solid var(--line);
  border-radius: 12px;
  background: #ffffff;
}

.hero {
  padding: 56px 0 38px;
}

.hero-grid {
  display: grid;
  grid-template-columns: 0.95fr 1.05fr;
  gap: 56px;
  align-items: center;
}

.eyebrow,
.section-kicker {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  margin: 0 0 16px;
  padding: 8px 14px;
  color: var(--primary-dark);
  background: #edf9f2;
  border: 1px solid #d8f0e3;
  border-radius: 999px;
  font-size: 14px;
  font-weight: 600;
}

.hero h1,
.section h2,
.section-alt h2 {
  margin: 0;
  line-height: 1.15;
}

.hero h1 {
  font-size: clamp(34px, 4.6vw, 56px);
  max-width: 11ch;
  letter-spacing: -0.02em;
}

.lead {
  margin: 18px 0 0;
  font-size: 17px;
  color: var(--muted);
  max-width: 58ch;
}

.hero-actions,
.cta-strip {
  display: flex;
  flex-wrap: wrap;
  gap: 14px;
  margin-top: 28px;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 50px;
  padding: 0 24px;
  border-radius: 14px;
  font-weight: 700;
  transition: transform 0.2s ease, box-shadow 0.2s ease, border-color 0.2s ease;
}

.btn:hover {
  transform: translateY(-1px);
}

.btn-primary {
  color: #ffffff;
  background: linear-gradient(135deg, var(--primary), #24c97b);
  box-shadow: 0 14px 30px rgba(22, 178, 107, 0.22);
}

.btn-secondary {
  color: var(--primary-dark);
  background: var(--secondary);
  border: 1px solid #d9efe2;
}

.hero-stats {
  display: flex;
  flex-wrap: wrap;
  gap: 24px;
  margin-top: 28px;
}

.hero-stats div {
  min-width: 120px;
}

.hero-stats strong {
  display: block;
  font-size: 28px;
  line-height: 1.1;
}

.hero-stats span {
  display: block;
  margin-top: 6px;
  color: var(--muted);
  font-size: 14px;
}

.hero-media {
  position: relative;
  display: flex;
  align-items: center;
  justify-content: center;
}

.hero-media::before {
  content: "";
  position: absolute;
  inset: auto auto 8% -3%;
  width: 240px;
  height: 240px;
  background: radial-gradient(circle, rgba(22, 178, 107, 0.18), transparent 70%);
  filter: blur(18px);
  pointer-events: none;
}

.hero-media img {
  width: auto;
  max-width: 100%;
  height: auto;
  border-radius: 24px;
  border: 1px solid #edf2f4;
  box-shadow: var(--shadow);
  object-fit: contain;
  background: #ffffff;
}

.section,
.section-soft {
  padding: 56px 0;
}

.metrics-strip {
  padding-top: 8px;
}

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

.section-head {
  max-width: 760px;
  margin-bottom: 28px;
}

.section-head h2 {
  font-size: clamp(28px, 4vw, 42px);
}

.section-head p,
.guide-grid p,
.download-card p,
.faq-item p,
.site-footer p {
  color: var(--muted);
}

.summary-grid,
.feature-grid,
.download-grid,
.version-grid {
  display: grid;
  gap: 18px;
}

.summary-grid {
  grid-template-columns: repeat(3, minmax(0, 1fr));
}

.summary-item {
  padding: 22px 24px;
  border-radius: 18px;
  background: var(--bg-accent);
  border: 1px solid #e1f2e8;
  text-align: center;
}

.summary-item strong {
  display: block;
  font-size: clamp(26px, 4vw, 36px);
  line-height: 1.1;
}

.summary-item span {
  display: block;
  margin-top: 8px;
  color: var(--muted);
}

.feature-grid {
  grid-template-columns: repeat(4, minmax(0, 1fr));
}

.card,
.download-card,
.faq-item,
.code-line {
  border: 1px solid var(--line);
  background: var(--card);
  box-shadow: var(--shadow);
}

.card {
  padding: 24px;
  border-radius: var(--radius);
}

.icon,
.platform-icon {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-width: 56px;
  height: 56px;
  margin-bottom: 16px;
  border-radius: 16px;
  padding: 0 14px;
  background: #edf9f2;
  color: var(--primary-dark);
  font-size: 16px;
  font-weight: 700;
}

.card h3,
.download-card h3,
.steps h3 {
  margin: 0 0 10px;
  font-size: 20px;
}

.card p,
.download-card p,
.faq-item p,
.steps p {
  margin: 0;
}

.guide-grid,
.footer-grid {
  display: grid;
  gap: 28px;
}

.download-grid {
  grid-template-columns: repeat(3, minmax(0, 1fr));
}

.download-card {
  padding: 28px 24px;
  border-radius: 20px;
  transition: transform 0.2s ease, border-color 0.2s ease;
  text-align: left;
}

.download-card:hover {
  transform: translateY(-2px);
  border-color: #cfe8da;
}

.download-copy {
  margin-top: 20px;
  padding: 18px 20px;
  border: 1px solid var(--line);
  border-radius: 18px;
  background: #fbfdfc;
}

.download-copy p,
.seo-copy p {
  margin: 0;
  color: var(--muted);
}

.download-copy p + p,
.seo-copy p + p {
  margin-top: 14px;
}

.version-grid {
  grid-template-columns: repeat(3, minmax(0, 1fr));
}

.version-card {
  padding: 24px;
  border: 1px solid var(--line);
  border-radius: 20px;
  background: #ffffff;
  box-shadow: var(--shadow);
}

.version-card h3 {
  margin: 0 0 10px;
  font-size: 20px;
}

.version-card p {
  margin: 0;
  color: var(--muted);
}

.more-link {
  margin: 18px 0 0;
}

.more-link a {
  color: #7edfff;
}

.guide-grid {
  grid-template-columns: 1fr 1fr;
  align-items: start;
}

.code-line {
  display: inline-flex;
  align-items: center;
  min-height: 48px;
  padding: 0 16px;
  border-radius: 14px;
  background: #ffffff;
}

.steps {
  margin: 0;
  padding-left: 22px;
}

.steps li + li {
  margin-top: 18px;
}

.cta-strip {
  margin-top: 24px;
}

.seo-copy {
  max-width: 980px;
}

.faq-list {
  display: grid;
  gap: 16px;
}

.faq-item {
  padding: 0;
  border-radius: 20px;
  overflow: hidden;
  box-shadow: none;
}

.faq-item summary {
  position: relative;
  padding: 20px 56px 20px 22px;
  cursor: pointer;
  list-style: none;
  font-weight: 600;
}

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

.faq-item summary::after {
  content: "+";
  position: absolute;
  top: 50%;
  right: 20px;
  transform: translateY(-50%);
  color: var(--primary-dark);
  font-size: 24px;
}

.faq-item[open] summary::after {
  content: "−";
}

.faq-item p {
  margin: 0;
  padding: 0 22px 22px;
}

.site-footer {
  padding: 56px 0 18px;
  background: #fbfdfc;
  border-top: 1px solid var(--line);
}

.footer-grid {
  grid-template-columns: 1.4fr 0.6fr;
  padding-bottom: 20px;
  border-bottom: 1px solid var(--line);
}

.brand-footer {
  margin-bottom: 16px;
}

.footer-links {
  display: grid;
  gap: 12px;
  justify-items: start;
  align-content: start;
}

.footer-bottom {
  padding-top: 18px;
}

.footer-bottom p {
  margin: 0;
  font-size: 14px;
}

@media (max-width: 1100px) {
  .feature-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .download-grid,
  .version-grid {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }
}

@media (max-width: 860px) {
  .menu-toggle {
    display: inline-flex;
  }

  .site-nav {
    position: absolute;
    top: calc(100% + 10px);
    right: 16px;
    left: 16px;
    display: none;
    flex-direction: column;
    align-items: flex-start;
    padding: 16px;
    background: rgba(255, 255, 255, 0.98);
    border: 1px solid var(--line);
    border-radius: 18px;
    box-shadow: var(--shadow);
  }

  .site-nav.is-open {
    display: flex;
  }

  .hero-grid,
  .guide-grid,
  .footer-grid {
    grid-template-columns: 1fr;
  }

  .hero h1 {
    max-width: none;
  }

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

  .version-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

@media (max-width: 640px) {
  .container {
    width: min(var(--container), calc(100% - 24px));
  }

  .section,
  .section-soft {
    padding: 34px 0;
  }

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

  .header-inner {
    min-height: 68px;
  }

  .hero-actions,
  .cta-strip {
    flex-direction: column;
  }

  .hero-stats {
    gap: 16px;
  }

  .btn {
    width: 100%;
  }
}