:root {
  --black: #080808;
  --surface: #121212;
  --surface-2: #1a1a1a;
  --line: rgba(255, 255, 255, 0.08);
  --text: #f5f5f5;
  --muted: #9a9a9a;
  --orange: #ff6600;
  --orange-dark: #e55a00;
  --orange-glow: rgba(255, 102, 0, 0.25);
  --purple: #7c3aed;
  --nav-h: 58px;
  --sticky-ads-h: 0px;
  --radius: 14px;
  --font: "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
}

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

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

body {
  font-family: var(--font);
  background: var(--black);
  color: var(--text);
  line-height: 1.8;
  min-height: 100vh;
  padding-bottom: calc(var(--sticky-ads-h) + env(safe-area-inset-bottom, 0px));
}

body::after {
  content: "";
  position: fixed;
  inset: 0;
  background-image:
    linear-gradient(rgba(255, 255, 255, 0.02) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255, 255, 255, 0.02) 1px, transparent 1px);
  background-size: 48px 48px;
  pointer-events: none;
  z-index: 0;
  opacity: 0.35;
}

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

a { color: var(--orange); text-decoration: none; transition: color 0.2s, opacity 0.2s; }
a:hover { color: #ff8533; }

.container {
  width: min(1140px, 92vw);
  margin: 0 auto;
  position: relative;
  z-index: 1;
}

/* Header */
.topbar {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: var(--nav-h);
  z-index: 1100;
  background: rgba(8, 8, 8, 0.72);
  backdrop-filter: blur(16px);
  border-bottom: 1px solid var(--line);
  transition: background 0.3s;
}

.topbar.scrolled { background: rgba(8, 8, 8, 0.96); }

.topbar-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 100%;
}

.logo-link {
  display: flex;
  align-items: center;
  gap: 10px;
  color: var(--text);
  font-weight: 800;
  font-size: 1.05rem;
  letter-spacing: 0.04em;
}

.logo-link img {
  width: 36px;
  height: 36px;
  border-radius: 9px;
}

.nav-toggle {
  display: none;
  background: none;
  border: 1px solid var(--line);
  color: var(--text);
  width: 40px;
  height: 40px;
  border-radius: 10px;
  font-size: 1.2rem;
  cursor: pointer;
}

.main-nav ul {
  display: flex;
  gap: 6px;
  list-style: none;
}

.main-nav a {
  display: block;
  padding: 8px 14px;
  color: var(--muted);
  font-size: 0.9rem;
  border-radius: 999px;
  transition: background 0.2s, color 0.2s;
}

.main-nav a:hover,
.main-nav a.active {
  color: var(--text);
  background: rgba(255, 102, 0, 0.12);
}

/* Ads */
.ads-section {
  padding-top: calc(var(--nav-h) + 12px);
  background: linear-gradient(180deg, rgba(255, 102, 0, 0.06), transparent);
}

#ads {
  display: flex;
  justify-content: center;
  align-items: flex-start;
  flex-wrap: wrap;
  gap: 8px;
  background: transparent;
  margin: 8px 0 14px;
}

#ads > div {
  display: flex;
  flex-direction: column;
  align-items: center;
  width: 70px;
}

#ads img {
  width: 65px;
  height: 65px;
  object-fit: cover;
  border-radius: 16px;
  box-shadow: 0 8px 20px rgba(0, 0, 0, 0.35);
  transition: transform 0.18s ease;
  border: 1px solid var(--line);
}

#ads a:hover img { transform: translateY(-3px) scale(1.03); }

#ads .caption {
  height: 15px;
  font-size: 11px;
  color: var(--muted);
  text-align: center;
  max-width: 72px;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
  margin-top: 4px;
}

.sticky-download {
  position: fixed;
  left: 0;
  right: 0;
  top: var(--nav-h);
  z-index: 1050;
  background: rgba(12, 12, 12, 0.96);
  border-bottom: 1px solid var(--line);
  padding: 4px 0 5px;
  transform: translateY(-110%);
  opacity: 0;
  transition: transform 0.28s ease, opacity 0.28s ease;
  pointer-events: none;
}

.sticky-download.visible {
  transform: translateY(0);
  opacity: 1;
  pointer-events: auto;
}

#sticky-ads {
  display: flex;
  justify-content: center;
  flex-wrap: wrap;
  gap: 4px 6px;
  max-width: 720px;
  margin: 0 auto;
  padding: 0 12px;
}

#sticky-ads > div {
  display: flex;
  flex-direction: column;
  align-items: center;
  width: calc(12.5% - 6px);
  min-width: 0;
  max-width: 56px;
}

#sticky-ads img {
  width: 44px;
  height: 44px;
  border-radius: 10px;
  object-fit: cover;
  border: 1px solid var(--line);
}

#sticky-ads .caption {
  font-size: 9px;
  color: var(--muted);
  text-align: center;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
  max-width: 52px;
  margin-top: 2px;
  line-height: 1.2;
}

/* Hero */
.hero-banner {
  padding: 36px 0 56px;
  overflow: hidden;
}

.hero-wrap {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 40px;
  align-items: center;
}

.hero-tag {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 6px 14px;
  border: 1px solid rgba(255, 102, 0, 0.35);
  border-radius: 999px;
  font-size: 0.78rem;
  color: var(--orange);
  margin-bottom: 18px;
  background: rgba(255, 102, 0, 0.08);
}

.hero-tag::before {
  content: "";
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--orange);
  box-shadow: 0 0 8px var(--orange);
}

.hero-banner h1 {
  font-size: clamp(1.75rem, 5vw, 2.65rem);
  line-height: 1.25;
  font-weight: 900;
  letter-spacing: -0.02em;
  margin-bottom: 16px;
}

.hero-banner h1 span { color: var(--orange); }

.hero-intro {
  color: var(--muted);
  font-size: 1rem;
  margin-bottom: 24px;
  max-width: 520px;
}

.hero-metrics {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 12px;
  margin-bottom: 28px;
}

.metric-box {
  padding: 14px;
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  text-align: center;
}

.metric-box strong {
  display: block;
  font-size: 1.1rem;
  color: var(--orange);
  margin-bottom: 2px;
}

.metric-box span { font-size: 0.75rem; color: var(--muted); }

.btn-primary {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 14px 28px;
  background: linear-gradient(135deg, var(--orange), var(--orange-dark));
  color: #fff;
  font-weight: 700;
  border-radius: 999px;
  border: none;
  cursor: pointer;
  font-size: 0.95rem;
  box-shadow: 0 12px 32px var(--orange-glow);
  transition: transform 0.2s, box-shadow 0.2s;
}

.btn-primary:hover {
  color: #fff;
  transform: translateY(-2px);
  box-shadow: 0 16px 40px var(--orange-glow);
}

.btn-outline {
  display: inline-flex;
  padding: 12px 22px;
  border: 1px solid var(--line);
  border-radius: 999px;
  color: var(--text);
  font-size: 0.9rem;
  margin-left: 10px;
}

.btn-outline:hover { border-color: var(--orange); color: var(--orange); }

.hero-visual {
  position: relative;
  height: 420px;
  display: flex;
  justify-content: center;
  align-items: center;
}

.phone-layer {
  position: absolute;
  width: 168px;
  border-radius: 22px;
  overflow: hidden;
  border: 2px solid rgba(255, 255, 255, 0.12);
  box-shadow: 0 24px 60px rgba(0, 0, 0, 0.55);
  transition: transform 0.4s ease;
}

.phone-layer:nth-child(1) { transform: rotate(-8deg) translateX(-90px) translateY(-10px); z-index: 1; }
.phone-layer:nth-child(2) { transform: rotate(4deg) translateX(20px) translateY(-30px); z-index: 3; }
.phone-layer:nth-child(3) { transform: rotate(-3deg) translateX(100px) translateY(20px); z-index: 2; }
.phone-layer:nth-child(4) { transform: rotate(10deg) translateX(-10px) translateY(40px); z-index: 4; width: 155px; opacity: 0.92; }

.hero-visual:hover .phone-layer:nth-child(1) { transform: rotate(-10deg) translateX(-95px) translateY(-16px); }
.hero-visual:hover .phone-layer:nth-child(3) { transform: rotate(-5deg) translateX(105px) translateY(14px); }

/* Sections */
.section-block { padding: 64px 0; }

.section-head {
  margin-bottom: 36px;
  max-width: 680px;
}

.section-num {
  font-size: 0.75rem;
  font-weight: 700;
  letter-spacing: 0.2em;
  color: var(--orange);
  margin-bottom: 8px;
}

.section-head h2 {
  font-size: clamp(1.4rem, 4vw, 2rem);
  font-weight: 800;
  line-height: 1.35;
  margin-bottom: 12px;
}

.section-head p { color: var(--muted); }

/* 3:7 layout */
.split-row {
  display: grid;
  grid-template-columns: 3fr 7fr;
  gap: 32px;
  align-items: start;
  margin-bottom: 48px;
}

.split-row.reverse { direction: rtl; }
.split-row.reverse > * { direction: ltr; }

.split-media {
  position: relative;
}

.split-media img {
  border-radius: 18px;
  border: 1px solid var(--line);
  box-shadow: 0 20px 50px rgba(0, 0, 0, 0.4);
}

.split-media figcaption {
  margin-top: 10px;
  font-size: 0.78rem;
  color: var(--muted);
  text-align: center;
}

.split-body h3 {
  font-size: 1.25rem;
  margin-bottom: 12px;
  color: var(--text);
}

.split-body p {
  color: #c8c8c8;
  margin-bottom: 14px;
  font-size: 0.95rem;
}

.split-body ul {
  margin: 12px 0 16px 20px;
  color: var(--muted);
}

.split-body li { margin-bottom: 8px; }

/* Feature bento */
.bento-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 16px;
}

.bento-item {
  padding: 24px;
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  transition: border-color 0.25s, transform 0.25s;
}

.bento-item:hover {
  border-color: rgba(255, 102, 0, 0.4);
  transform: translateY(-3px);
}

.bento-icon {
  width: 44px;
  height: 44px;
  border-radius: 12px;
  background: rgba(255, 102, 0, 0.12);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.3rem;
  margin-bottom: 14px;
}

.bento-item h3 { font-size: 1rem; margin-bottom: 8px; }
.bento-item p { font-size: 0.88rem; color: var(--muted); line-height: 1.65; }

/* Preview strip */
.preview-strip {
  display: flex;
  gap: 14px;
  overflow-x: auto;
  scroll-snap-type: x mandatory;
  padding-bottom: 8px;
  -webkit-overflow-scrolling: touch;
}

.preview-strip::-webkit-scrollbar { height: 4px; }
.preview-strip::-webkit-scrollbar-thumb { background: var(--orange); border-radius: 4px; }

.preview-card {
  flex: 0 0 220px;
  scroll-snap-align: start;
  background: var(--surface);
  border-radius: var(--radius);
  overflow: hidden;
  border: 1px solid var(--line);
}

.preview-card img { aspect-ratio: 9/16; object-fit: cover; width: 100%; }
.preview-card .cap { padding: 12px; font-size: 0.82rem; color: var(--muted); }

/* Prose / SEO blocks */
.prose-block {
  max-width: 900px;
  margin: 0 auto 40px;
}

.prose-block h3 {
  font-size: 1.15rem;
  margin: 24px 0 12px;
  color: var(--text);
}

.prose-block p {
  color: #c4c4c4;
  font-size: 0.94rem;
  margin-bottom: 14px;
}

.prose-columns {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 28px 36px;
  margin-top: 20px;
}

.prose-columns h4 {
  font-size: 0.95rem;
  color: var(--orange);
  margin-bottom: 8px;
}

.prose-columns p { font-size: 0.9rem; color: var(--muted); }

.feature-gallery {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 16px;
  margin-top: 32px;
}

.gallery-card {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  overflow: hidden;
}

.gallery-card img {
  width: 100%;
  aspect-ratio: 9/14;
  object-fit: cover;
}

.gallery-card .gallery-body {
  padding: 14px;
}

.gallery-card h4 { font-size: 0.9rem; margin-bottom: 6px; }
.gallery-card p { font-size: 0.82rem; color: var(--muted); line-height: 1.6; }

/* FAQ */
.faq-list { max-width: 820px; }

.faq-item {
  border-bottom: 1px solid var(--line);
  padding: 20px 0;
}

.faq-item h3 { font-size: 1rem; margin-bottom: 8px; }
.faq-item p { color: var(--muted); font-size: 0.92rem; }

/* CTA band */
.cta-band {
  margin: 48px 0 0;
  padding: 48px 32px;
  text-align: center;
  background: linear-gradient(135deg, rgba(255, 102, 0, 0.15), rgba(124, 58, 237, 0.1));
  border: 1px solid rgba(255, 102, 0, 0.25);
  border-radius: 24px;
}

.cta-band h2 { font-size: 1.5rem; margin-bottom: 10px; }
.cta-band p { color: var(--muted); margin-bottom: 22px; }

/* Sub pages */
.page-hero {
  padding: calc(var(--nav-h) + 40px) 0 32px;
  border-bottom: 1px solid var(--line);
}

.page-hero h1 { font-size: clamp(1.5rem, 4vw, 2.2rem); margin-bottom: 10px; }
.page-hero p { color: var(--muted); }

.breadcrumb {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  font-size: 0.82rem;
  color: var(--muted);
  margin-bottom: 16px;
}

.breadcrumb a { color: var(--muted); }
.breadcrumb a:hover { color: var(--orange); }
.breadcrumb span { color: var(--text); }

.legal-content {
  padding: 40px 0 64px;
  max-width: 820px;
}

.legal-content h2 {
  font-size: 1.15rem;
  margin: 28px 0 12px;
  color: var(--orange);
}

.legal-content p,
.legal-content li {
  color: #bdbdbd;
  font-size: 0.92rem;
  margin-bottom: 12px;
}

.legal-content ul { margin-left: 20px; }

/* Error pages */
.error-page {
  min-height: 70vh;
  display: flex;
  align-items: center;
  justify-content: center;
  text-align: center;
  padding: calc(var(--nav-h) + 40px) 20px 60px;
}

.error-code {
  font-size: clamp(4rem, 15vw, 7rem);
  font-weight: 900;
  color: var(--orange);
  line-height: 1;
  margin-bottom: 12px;
}

.error-page h1 { font-size: 1.4rem; margin-bottom: 10px; }
.error-page p { color: var(--muted); margin-bottom: 24px; }

/* Footer */
.site-footer {
  border-top: 1px solid var(--line);
  padding: 40px 0 32px;
  background: var(--surface);
}

.footer-grid {
  display: grid;
  grid-template-columns: 1.2fr 1fr 1fr;
  gap: 32px;
  margin-bottom: 28px;
}

.footer-brand img { width: 44px; border-radius: 10px; margin-bottom: 12px; }
.footer-brand p { font-size: 0.85rem; color: var(--muted); max-width: 280px; }

.footer-col h4 {
  font-size: 0.85rem;
  margin-bottom: 14px;
  color: var(--text);
}

.footer-col ul { list-style: none; }
.footer-col li { margin-bottom: 8px; }
.footer-col a { color: var(--muted); font-size: 0.85rem; }
.footer-col a:hover { color: var(--orange); }

.footer-bottom {
  padding-top: 20px;
  border-top: 1px solid var(--line);
  font-size: 0.78rem;
  color: #666;
  text-align: center;
}

/* Responsive */
@media (max-width: 900px) {
  .hero-wrap { grid-template-columns: 1fr; }
  .hero-visual { height: 340px; margin-top: 10px; }
  .phone-layer { width: 140px; }
  .phone-layer:nth-child(1) { transform: rotate(-8deg) translateX(-70px); }
  .phone-layer:nth-child(2) { transform: rotate(4deg) translateX(10px) translateY(-20px); }
  .phone-layer:nth-child(3) { transform: rotate(-3deg) translateX(75px) translateY(10px); }
  .phone-layer:nth-child(4) { transform: rotate(8deg) translateX(-5px) translateY(30px); width: 130px; }
  .split-row { grid-template-columns: 1fr; }
  .split-row.reverse { direction: ltr; }
  .bento-grid { grid-template-columns: 1fr 1fr; }
  .footer-grid { grid-template-columns: 1fr; }
  .btn-outline { margin: 12px 0 0; display: inline-flex; }
}

@media (max-width: 768px) {
  .nav-toggle { display: block; }

  .main-nav {
    position: fixed;
    top: var(--nav-h);
    left: 0;
    right: 0;
    background: rgba(8, 8, 8, 0.98);
    border-bottom: 1px solid var(--line);
    padding: 12px;
    transform: translateY(-120%);
    opacity: 0;
    pointer-events: none;
    transition: transform 0.25s, opacity 0.25s;
  }

  .main-nav.open {
    transform: translateY(0);
    opacity: 1;
    pointer-events: auto;
  }

  .main-nav ul { flex-direction: column; }
  .main-nav a { padding: 12px 16px; }

  .hero-metrics { grid-template-columns: 1fr; }
  .bento-grid { grid-template-columns: 1fr; }

  .sticky-download {
    top: auto;
    bottom: 0;
    border-top: 1px solid var(--line);
    border-bottom: none;
    padding: 10px 0 calc(10px + env(safe-area-inset-bottom, 0px));
  }

  #sticky-ads > div { width: calc(25% - 6px); max-width: 52px; }
  #sticky-ads img { width: 40px; height: 40px; border-radius: 9px; }
  #sticky-ads .caption { font-size: 8px; max-width: 48px; }

  body.has-sticky-ads { padding-bottom: calc(68px + env(safe-area-inset-bottom, 0px)); }

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

@media (min-width: 769px) {
  #sticky-ads > div { width: calc(12.5% - 6px); max-width: 56px; }
  body.has-sticky-ads { padding-top: 0; }
  body.has-sticky-ads .sticky-download.visible ~ main,
  body.has-sticky-ads .sticky-download.visible ~ .page-hero { margin-top: 0; }
}