/* YshopAdmin static landing ?? blue theme, mobile-first */
:root {
  --primary: #1677ff;
  --primary-dark: #0958d9;
  --primary-light: #e6f4ff;
  --primary-soft: #f0f5ff;
  --text: #1f1f1f;
  --text-secondary: #595959;
  --text-muted: #8c8c8c;
  --border: #e8e8e8;
  --bg: #ffffff;
  --bg-alt: #f7f9fc;
  --shadow: 0 4px 24px rgba(22, 119, 255, 0.08);
  --shadow-nav: 0 2px 12px rgba(0, 0, 0, 0.06);
  --radius: 12px;
  --radius-sm: 8px;
  --max: 1160px;
  --header-h: 64px;
  --font: "Segoe UI", "PingFang SC", "Microsoft YaHei", system-ui, sans-serif;
}

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

html {
  scroll-behavior: smooth;
  scroll-padding-top: calc(var(--header-h) + 12px);
}

body {
  margin: 0;
  font-family: var(--font);
  color: var(--text);
  background: var(--bg);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

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

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

a:hover {
  color: var(--primary-dark);
}

.container {
  width: 100%;
  max-width: var(--max);
  margin: 0 auto;
  padding: 0 20px;
}

/* ???? Header ???? */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  height: var(--header-h);
  background: rgba(255, 255, 255, 0.92);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid transparent;
  transition: box-shadow 0.25s, border-color 0.25s;
}

.site-header.is-scrolled {
  box-shadow: var(--shadow-nav);
  border-bottom-color: var(--border);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: var(--header-h);
  gap: 16px;
}

.brand {
  display: flex;
  align-items: center;
  gap: 10px;
  color: var(--text);
  font-weight: 700;
  font-size: 1.15rem;
  flex-shrink: 0;
}

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

.brand img {
  width: 32px;
  height: 32px;
}

.nav-desktop {
  display: none;
  align-items: center;
  gap: 4px;
  list-style: none;
  margin: 0;
  padding: 0;
}

.nav-desktop a {
  display: block;
  padding: 8px 14px;
  color: var(--text-secondary);
  font-size: 0.95rem;
  border-radius: 6px;
  transition: color 0.2s, background 0.2s;
}

.nav-desktop a:hover,
.nav-desktop a.is-active {
  color: var(--primary);
  background: var(--primary-light);
}

.header-actions {
  display: none;
  align-items: center;
  gap: 10px;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 6px;
  padding: 10px 20px;
  font-size: 0.95rem;
  font-weight: 500;
  border-radius: var(--radius-sm);
  border: 1px solid transparent;
  cursor: pointer;
  transition: background 0.2s, color 0.2s, border-color 0.2s, box-shadow 0.2s;
  font-family: inherit;
  white-space: nowrap;
}

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

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

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

.btn-outline:hover {
  background: var(--primary-light);
  color: var(--primary-dark);
}

.btn-ghost {
  background: rgba(255, 255, 255, 0.15);
  color: #fff;
  border-color: rgba(255, 255, 255, 0.45);
}

.btn-ghost:hover {
  background: rgba(255, 255, 255, 0.28);
  color: #fff;
}

.btn-lg {
  padding: 12px 28px;
  font-size: 1rem;
}

.menu-toggle {
  display: flex;
  flex-direction: column;
  justify-content: center;
  gap: 5px;
  width: 40px;
  height: 40px;
  padding: 8px;
  border: none;
  background: transparent;
  cursor: pointer;
  border-radius: 6px;
}

.menu-toggle span {
  display: block;
  height: 2px;
  background: var(--text);
  border-radius: 1px;
  transition: transform 0.25s, opacity 0.25s;
}

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

.menu-toggle[aria-expanded="true"] span:nth-child(2) {
  opacity: 0;
}

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

.nav-mobile {
  display: none;
  position: absolute;
  top: var(--header-h);
  left: 0;
  right: 0;
  background: #fff;
  border-bottom: 1px solid var(--border);
  box-shadow: var(--shadow-nav);
  padding: 12px 20px 20px;
}

.nav-mobile.is-open {
  display: block;
}

.nav-mobile ul {
  list-style: none;
  margin: 0 0 16px;
  padding: 0;
}

.nav-mobile a {
  display: block;
  padding: 12px 8px;
  color: var(--text);
  border-bottom: 1px solid var(--border);
}

.nav-mobile .mobile-actions {
  display: flex;
  flex-direction: column;
  gap: 10px;
}

/* ???? Hero ???? */
.hero {
  position: relative;
  padding: 56px 0 48px;
  background:
    radial-gradient(ellipse 80% 60% at 70% 20%, rgba(22, 119, 255, 0.12), transparent 60%),
    linear-gradient(165deg, #0a1f44 0%, #1677ff 55%, #69b1ff 100%);
  color: #fff;
  overflow: hidden;
}

.hero::after {
  content: "";
  position: absolute;
  inset: 0;
  background:
    linear-gradient(90deg, transparent 0%, rgba(255, 255, 255, 0.03) 50%, transparent 100%);
  pointer-events: none;
}

.hero-inner {
  position: relative;
  z-index: 1;
  text-align: center;
  max-width: 820px;
  margin: 0 auto;
}

.hero-badge {
  display: inline-block;
  padding: 4px 14px;
  margin-bottom: 20px;
  font-size: 0.8rem;
  letter-spacing: 0.04em;
  border-radius: 999px;
  background: rgba(255, 255, 255, 0.15);
  border: 1px solid rgba(255, 255, 255, 0.25);
}

.hero h1 {
  margin: 0 0 16px;
  font-size: clamp(2rem, 6vw, 3.25rem);
  font-weight: 800;
  letter-spacing: -0.02em;
  line-height: 1.2;
}

.hero-lead {
  margin: 0 auto 32px;
  font-size: clamp(1rem, 2.5vw, 1.2rem);
  opacity: 0.92;
  max-width: 560px;
  line-height: 1.7;
}

.hero-ctas {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 12px;
  margin-bottom: 40px;
}

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

.hero .hero-ctas .btn-primary:hover {
  background: var(--primary-light);
  color: var(--primary-dark);
}

.tech-strip {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 20px 28px;
  padding-top: 28px;
  border-top: 1px solid rgba(255, 255, 255, 0.2);
}

.tech-strip figure {
  margin: 0;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 8px;
  font-size: 0.75rem;
  opacity: 0.9;
}

.tech-strip img {
  width: 40px;
  height: 40px;
  border-radius: 8px;
  background: rgba(255, 255, 255, 0.12);
  padding: 4px;
}

/* ???? Sections common ???? */
.section {
  padding: 64px 0;
}

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

.section-head {
  text-align: center;
  margin-bottom: 40px;
}

.section-head h2 {
  margin: 0 0 12px;
  font-size: clamp(1.5rem, 3.5vw, 2rem);
  font-weight: 700;
  color: var(--text);
}

.section-head p {
  margin: 0 auto;
  max-width: 560px;
  color: var(--text-secondary);
  font-size: 1rem;
}

/* ???? Feature strip (5) ???? */
.feature-strip {
  display: grid;
  grid-template-columns: 1fr;
  gap: 16px;
  margin-top: -36px;
  position: relative;
  z-index: 2;
}

.feature-chip {
  display: flex;
  align-items: center;
  gap: 14px;
  padding: 18px 20px;
  background: #fff;
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  border: 1px solid var(--border);
}

.feature-chip .icon {
  flex-shrink: 0;
  width: 44px;
  height: 44px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 10px;
  background: var(--primary-light);
  color: var(--primary);
}

.feature-chip .icon svg {
  width: 22px;
  height: 22px;
}

.feature-chip strong {
  display: block;
  font-size: 0.95rem;
  margin-bottom: 2px;
}

.feature-chip span {
  font-size: 0.8rem;
  color: var(--text-muted);
}

/* ???? Pillars (3) ???? */
.pillars {
  display: grid;
  grid-template-columns: 1fr;
  gap: 20px;
}

.pillar {
  padding: 28px 24px;
  background: #fff;
  border-radius: var(--radius);
  border: 1px solid var(--border);
  transition: box-shadow 0.25s, border-color 0.25s;
}

.pillar:hover {
  box-shadow: var(--shadow);
  border-color: #91caff;
}

.pillar-num {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 36px;
  height: 36px;
  margin-bottom: 14px;
  border-radius: 50%;
  background: var(--primary);
  color: #fff;
  font-weight: 700;
  font-size: 0.9rem;
}

.pillar h3 {
  margin: 0 0 10px;
  font-size: 1.15rem;
}

.pillar p {
  margin: 0 0 14px;
  color: var(--text-secondary);
  font-size: 0.92rem;
}

.pillar ul {
  margin: 0;
  padding: 0;
  list-style: none;
}

.pillar li {
  position: relative;
  padding: 6px 0 6px 18px;
  font-size: 0.88rem;
  color: var(--text-secondary);
}

.pillar li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 14px;
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--primary);
}

/* ???? Module grid ???? */
.module-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 16px;
}

.module-card {
  padding: 22px 18px;
  text-align: center;
  background: #fff;
  border-radius: var(--radius);
  border: 1px solid var(--border);
  transition: transform 0.2s, box-shadow 0.2s, border-color 0.2s;
}

.module-card:hover {
  transform: translateY(-3px);
  box-shadow: var(--shadow);
  border-color: #91caff;
}

.module-card .icon {
  width: 48px;
  height: 48px;
  margin: 0 auto 12px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 12px;
  background: var(--primary-soft);
  color: var(--primary);
}

.module-card .icon svg {
  width: 24px;
  height: 24px;
}

.module-card h3 {
  margin: 0 0 6px;
  font-size: 0.98rem;
}

.module-card p {
  margin: 0;
  font-size: 0.82rem;
  color: var(--text-muted);
  line-height: 1.5;
}

/* ???? Advantages ???? */
.adv-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 16px;
}

.adv-card {
  display: flex;
  gap: 16px;
  padding: 24px;
  background: #fff;
  border-radius: var(--radius);
  border: 1px solid var(--border);
}

.adv-card .adv-icon {
  flex-shrink: 0;
  width: 40px;
  height: 40px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 10px;
  background: var(--primary);
  color: #fff;
  font-weight: 700;
  font-size: 0.85rem;
}

.adv-card h3 {
  margin: 0 0 6px;
  font-size: 1rem;
}

.adv-card p {
  margin: 0;
  font-size: 0.88rem;
  color: var(--text-secondary);
}

/* ???? Tech composition rings ???? */
.tech-compose {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 36px;
}

.ring-chart {
  position: relative;
  width: min(260px, 80vw);
  height: min(260px, 80vw);
}

.ring-chart svg {
  width: 100%;
  height: 100%;
  transform: rotate(-90deg);
}

.ring-center {
  position: absolute;
  inset: 28%;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  text-align: center;
  background: #fff;
  border-radius: 50%;
  box-shadow: var(--shadow);
}

.ring-center strong {
  font-size: 1.1rem;
  color: var(--primary);
}

.ring-center span {
  font-size: 0.75rem;
  color: var(--text-muted);
}

.ring-legend {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 12px 20px;
  width: 100%;
  max-width: 420px;
}

.ring-legend li {
  display: flex;
  align-items: center;
  gap: 8px;
  list-style: none;
  font-size: 0.88rem;
  color: var(--text-secondary);
}

.ring-legend {
  margin: 0;
  padding: 0;
}

.dot {
  width: 10px;
  height: 10px;
  border-radius: 50%;
  flex-shrink: 0;
}

/* ???? Ideas (4) ???? */
.ideas {
  display: grid;
  grid-template-columns: 1fr;
  gap: 16px;
}

.idea-card {
  padding: 28px 22px;
  text-align: center;
  background: linear-gradient(160deg, #fff 0%, var(--primary-soft) 100%);
  border-radius: var(--radius);
  border: 1px solid #d6e4ff;
}

.idea-card .idea-icon {
  width: 52px;
  height: 52px;
  margin: 0 auto 14px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 50%;
  background: #fff;
  color: var(--primary);
  box-shadow: 0 2px 8px rgba(22, 119, 255, 0.15);
}

.idea-card .idea-icon svg {
  width: 26px;
  height: 26px;
}

.idea-card h3 {
  margin: 0 0 8px;
  font-size: 1.05rem;
}

.idea-card p {
  margin: 0;
  font-size: 0.88rem;
  color: var(--text-secondary);
}

/* ???? Devices ???? */
.device-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 24px;
}

.device-card {
  background: #fff;
  border-radius: var(--radius);
  border: 1px solid var(--border);
  overflow: hidden;
  transition: box-shadow 0.25s;
}

.device-card:hover {
  box-shadow: var(--shadow);
}

.device-card .preview {
  padding: 16px;
  background: var(--bg-alt);
}

.device-card .preview img {
  width: 100%;
  border-radius: 6px;
}

.device-card .meta {
  padding: 18px 20px 22px;
}

.device-card h3 {
  margin: 0 0 6px;
  font-size: 1.05rem;
}

.device-card p {
  margin: 0 0 12px;
  font-size: 0.88rem;
  color: var(--text-secondary);
}

.device-card .path {
  display: inline-block;
  padding: 2px 10px;
  font-size: 0.78rem;
  font-family: Consolas, "Courier New", monospace;
  background: var(--primary-light);
  color: var(--primary-dark);
  border-radius: 4px;
}

/* ???? Ecosystem ???? */
.eco-list {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 12px;
  margin: 0;
  padding: 0;
  list-style: none;
}

.eco-list a {
  display: inline-flex;
  align-items: center;
  padding: 10px 18px;
  background: #fff;
  border: 1px solid var(--border);
  border-radius: 999px;
  color: var(--text-secondary);
  font-size: 0.9rem;
  transition: border-color 0.2s, color 0.2s, background 0.2s;
}

.eco-list a:hover {
  border-color: var(--primary);
  color: var(--primary);
  background: var(--primary-light);
}

/* ???? Footer ???? */
.site-footer {
  background: #0a1f44;
  color: rgba(255, 255, 255, 0.75);
  padding: 48px 0 28px;
}

.footer-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 28px;
  margin-bottom: 36px;
}

.footer-brand {
  display: flex;
  align-items: center;
  gap: 10px;
  margin-bottom: 12px;
  color: #fff;
  font-weight: 700;
  font-size: 1.1rem;
}

.footer-brand img {
  width: 28px;
  height: 28px;
}

.footer-desc {
  margin: 0;
  font-size: 0.88rem;
  line-height: 1.7;
  max-width: 320px;
}

.footer-col h4 {
  margin: 0 0 14px;
  color: #fff;
  font-size: 0.95rem;
}

.footer-col ul {
  margin: 0;
  padding: 0;
  list-style: none;
}

.footer-col a {
  display: block;
  padding: 5px 0;
  color: rgba(255, 255, 255, 0.7);
  font-size: 0.88rem;
}

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

.footer-bottom {
  padding-top: 20px;
  border-top: 1px solid rgba(255, 255, 255, 0.12);
  text-align: center;
  font-size: 0.82rem;
  color: rgba(255, 255, 255, 0.5);
}

/* ???? Back to top ???? */
.back-top {
  position: fixed;
  right: 20px;
  bottom: 24px;
  z-index: 90;
  width: 44px;
  height: 44px;
  display: flex;
  align-items: center;
  justify-content: center;
  border: none;
  border-radius: 50%;
  background: var(--primary);
  color: #fff;
  cursor: pointer;
  box-shadow: 0 4px 16px rgba(22, 119, 255, 0.35);
  opacity: 0;
  visibility: hidden;
  transform: translateY(12px);
  transition: opacity 0.25s, visibility 0.25s, transform 0.25s, background 0.2s;
}

.back-top.is-visible {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
}

.back-top:hover {
  background: var(--primary-dark);
}

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

/* ???? Fade-in ???? */
.reveal {
  opacity: 0;
  transform: translateY(16px);
  transition: opacity 0.5s ease, transform 0.5s ease;
}

.reveal.is-in {
  opacity: 1;
  transform: translateY(0);
}

/* ???? Responsive ???? */
@media (min-width: 480px) {
  .feature-strip {
    grid-template-columns: 1fr 1fr;
  }

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

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

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

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

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

  .header-actions {
    display: flex;
  }

  .menu-toggle {
    display: none;
  }

  .nav-mobile {
    display: none !important;
  }

  .feature-strip {
    grid-template-columns: repeat(3, 1fr);
  }

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

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

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

  .tech-compose {
    flex-direction: row;
    justify-content: center;
    gap: 56px;
  }

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

  .footer-grid {
    grid-template-columns: 2fr 1fr 1fr 1fr;
  }
}

@media (min-width: 1024px) {
  .section {
    padding: 80px 0;
  }

  .feature-strip {
    grid-template-columns: repeat(5, 1fr);
  }

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

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

  .hero {
    padding: 80px 0 64px;
  }
}