/* 91PO Official Site — Original Design System */
:root {
  --bg-deep: #08080b;
  --bg-card: #12121a;
  --bg-elevated: #1a1a24;
  --orange: #ff7a00;
  --orange-light: #ff9a3d;
  --orange-glow: rgba(255, 122, 0, 0.35);
  --purple: #a855f7;
  --gold: #d4a843;
  --text-primary: #f4f4f5;
  --text-secondary: #a1a1aa;
  --text-muted: #71717a;
  --border: rgba(255, 122, 0, 0.15);
  --radius: 14px;
  --radius-lg: 22px;
  --nav-h: 60px;
  --sticky-ads-h: 0px;
  --font: "PingFang SC", "Microsoft YaHei", "Helvetica Neue", 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(--bg-deep);
  color: var(--text-primary);
  line-height: 1.75;
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
}
body.has-sticky-ads .site-header { box-shadow: 0 2px 12px rgba(0,0,0,0.3); }

img { max-width: 100%; height: auto; display: block; }
a { color: var(--orange-light); text-decoration: none; transition: color 0.2s; }
a:hover { color: var(--orange); }

.container { width: min(1140px, 92vw); margin: 0 auto; }

/* ── Header ── */
.site-header {
  position: fixed;
  top: 0; left: 0; right: 0;
  z-index: 1000;
  height: var(--nav-h);
  background: rgba(8, 8, 11, 0.92);
  backdrop-filter: blur(16px);
  border-bottom: 1px solid var(--border);
}

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

.brand {
  display: flex;
  align-items: center;
  gap: 10px;
  color: var(--text-primary);
  font-weight: 700;
  font-size: 1.05rem;
  letter-spacing: 0.02em;
}

.brand img { width: 38px; height: 38px; border-radius: 10px; }

.nav-desktop { display: none; gap: 28px; list-style: none; }
.nav-desktop a { color: var(--text-secondary); font-size: 0.92rem; font-weight: 500; }
.nav-desktop a:hover, .nav-desktop a.active { color: var(--orange); }

.nav-toggle {
  display: flex;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 6px;
}
.nav-toggle span {
  display: block;
  width: 22px;
  height: 2px;
  background: var(--text-primary);
  border-radius: 2px;
  transition: 0.3s;
}

.nav-mobile {
  display: none;
  position: fixed;
  top: var(--nav-h);
  left: 0; right: 0;
  background: rgba(8, 8, 11, 0.98);
  border-bottom: 1px solid var(--border);
  padding: 16px 0;
  z-index: 999;
}
.nav-mobile.open { display: block; }
.nav-mobile ul { list-style: none; }
.nav-mobile li a {
  display: block;
  padding: 14px 5vw;
  color: var(--text-secondary);
  font-size: 1rem;
  border-bottom: 1px solid rgba(255,255,255,0.04);
}
.nav-mobile li a:hover { color: var(--orange); background: rgba(255,122,0,0.05); }

/* ── Sticky Ads Bar ── */
.sticky-ads-bar {
  position: fixed;
  top: var(--nav-h);
  left: 0; right: 0;
  z-index: 998;
  background: rgba(12, 12, 18, 0.97);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border);
  padding: 8px 0;
  transform: translateY(-100%);
  opacity: 0;
  pointer-events: none;
  transition: transform 0.35s ease, opacity 0.35s ease;
}
.sticky-ads-bar.visible {
  transform: translateY(0);
  opacity: 1;
  pointer-events: auto;
}

/* ── Ads Block ── */
#ads, #sticky-ads {
  display: flex;
  justify-content: center;
  align-items: flex-start;
  flex-wrap: wrap;
  background: transparent;
  margin: 10px 0;
  gap: 6px;
}
#ads > div, #sticky-ads > div {
  display: flex;
  flex-direction: column;
  align-items: center;
  width: calc(25% - 6px);
  box-sizing: border-box;
}
#ads img, #sticky-ads img {
  width: 65px;
  height: 65px;
  object-fit: cover;
  border-radius: 16px;
  box-shadow: 0 4px 16px rgba(0,0,0,0.4);
  transition: transform 0.18s ease;
  border: 1px solid rgba(255,122,0,0.2);
}
#ads a, #sticky-ads a { display: inline-block; border-radius: 16px; }
#ads img:hover, #sticky-ads img:hover { transform: translateY(-3px) scale(1.04); }
#ads figcaption, #ads .caption,
#sticky-ads figcaption, #sticky-ads .caption {
  height: 15px;
  font-size: 11px;
  color: var(--text-muted);
  text-align: center;
  max-width: 72px;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
  margin-top: 4px;
}

.ads-section { padding-top: calc(var(--nav-h) + 8px); }

/* ── Hero ── */
.hero {
  position: relative;
  padding: 48px 0 64px;
  overflow: hidden;
}
.hero::before {
  content: "";
  position: absolute;
  inset: 0;
  background:
    radial-gradient(ellipse 60% 50% at 80% 20%, rgba(255,122,0,0.12) 0%, transparent 70%),
    radial-gradient(ellipse 40% 40% at 10% 80%, rgba(168,85,247,0.08) 0%, transparent 60%);
  pointer-events: none;
}
.hero-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 40px;
  align-items: center;
  position: relative;
}
.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 6px 14px;
  background: rgba(255,122,0,0.1);
  border: 1px solid rgba(255,122,0,0.25);
  border-radius: 100px;
  font-size: 0.82rem;
  color: var(--orange-light);
  margin-bottom: 18px;
}
.hero-badge::before {
  content: "";
  width: 7px; height: 7px;
  background: var(--orange);
  border-radius: 50%;
  animation: pulse 2s infinite;
}
@keyframes pulse {
  0%, 100% { opacity: 1; }
  50% { opacity: 0.4; }
}
.hero h1 {
  font-size: clamp(1.75rem, 5vw, 2.6rem);
  font-weight: 800;
  line-height: 1.25;
  margin-bottom: 16px;
  background: linear-gradient(135deg, #fff 30%, var(--orange-light));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}
.hero-desc {
  font-size: 1rem;
  color: var(--text-secondary);
  margin-bottom: 28px;
  max-width: 520px;
}
.hero-tags { display: flex; flex-wrap: wrap; gap: 10px; }
.hero-tag {
  padding: 6px 14px;
  background: var(--bg-elevated);
  border: 1px solid var(--border);
  border-radius: 8px;
  font-size: 0.82rem;
  color: var(--text-secondary);
}

/* Hero Phone Stack */
.hero-phones {
  position: relative;
  height: 380px;
  margin: 0 auto;
  max-width: 340px;
}
.phone-card {
  position: absolute;
  width: 175px;
  border-radius: 20px;
  overflow: hidden;
  box-shadow: 0 20px 60px rgba(0,0,0,0.55), 0 0 0 1px rgba(255,122,0,0.15);
  transition: transform 0.4s ease;
}
.phone-card img { width: 100%; aspect-ratio: 9/19; object-fit: cover; }
.phone-card:nth-child(1) { top: 20px; left: 0; transform: rotate(-8deg); z-index: 1; }
.phone-card:nth-child(2) { top: 0; left: 50%; transform: translateX(-50%) rotate(2deg); z-index: 3; width: 195px; }
.phone-card:nth-child(3) { top: 30px; right: 0; transform: rotate(7deg); z-index: 2; }
.phone-card:nth-child(4) { bottom: 0; left: 50%; transform: translateX(-50%) rotate(-3deg); z-index: 4; width: 160px; opacity: 0.85; }

/* ── Section Common ── */
section { padding: 64px 0; }
.section-label {
  display: inline-block;
  font-size: 0.78rem;
  font-weight: 600;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--orange);
  margin-bottom: 10px;
}
.section-title {
  font-size: clamp(1.4rem, 3.5vw, 2rem);
  font-weight: 700;
  margin-bottom: 12px;
  line-height: 1.3;
}
.section-desc {
  color: var(--text-secondary);
  font-size: 0.95rem;
  max-width: 640px;
  margin-bottom: 40px;
}

/* ── Stats Row ── */
.stats-row {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 16px;
  margin-top: 48px;
}
.stat-item {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 20px 16px;
  text-align: center;
}
.stat-num {
  font-size: 1.6rem;
  font-weight: 800;
  color: var(--orange);
  line-height: 1.2;
}
.stat-label { font-size: 0.82rem; color: var(--text-muted); margin-top: 4px; }

/* ── Feature Bento ── */
.features-bento {
  display: grid;
  grid-template-columns: 1fr;
  gap: 16px;
}
.feature-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 28px 24px;
  position: relative;
  overflow: hidden;
  transition: border-color 0.3s, transform 0.3s;
}
.feature-card:hover {
  border-color: rgba(255,122,0,0.4);
  transform: translateY(-2px);
}
.feature-card::after {
  content: "";
  position: absolute;
  top: -40px; right: -40px;
  width: 100px; height: 100px;
  background: radial-gradient(circle, var(--orange-glow), transparent 70%);
  pointer-events: none;
}
.feature-icon {
  width: 44px; height: 44px;
  background: rgba(255,122,0,0.12);
  border-radius: 12px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.3rem;
  margin-bottom: 16px;
}
.feature-card h3 { font-size: 1.05rem; font-weight: 700; margin-bottom: 8px; }
.feature-card p { font-size: 0.88rem; color: var(--text-secondary); line-height: 1.65; }

/* ── Content Block 3:7 Ratio ── */
.content-block {
  display: grid;
  grid-template-columns: 1fr;
  gap: 28px;
  align-items: center;
  margin-bottom: 56px;
}
.content-block.reverse .content-text { order: 2; }
.content-block.reverse .content-visual { order: 1; }
.content-text h3 {
  font-size: 1.2rem;
  font-weight: 700;
  margin-bottom: 12px;
  color: var(--text-primary);
}
.content-text p {
  font-size: 0.92rem;
  color: var(--text-secondary);
  margin-bottom: 12px;
}
.content-text ul {
  list-style: none;
  margin-top: 12px;
}
.content-text li {
  font-size: 0.88rem;
  color: var(--text-secondary);
  padding: 6px 0 6px 20px;
  position: relative;
}
.content-text li::before {
  content: "";
  position: absolute;
  left: 0; top: 14px;
  width: 8px; height: 8px;
  background: var(--orange);
  border-radius: 2px;
  transform: rotate(45deg);
}
.content-visual {
  position: relative;
  border-radius: var(--radius-lg);
  overflow: hidden;
  border: 1px solid var(--border);
  box-shadow: 0 16px 48px rgba(0,0,0,0.4);
}
.content-visual img { width: 100%; aspect-ratio: 9/16; object-fit: cover; max-height: 520px; }
.content-visual .visual-tag {
  position: absolute;
  bottom: 12px; left: 12px;
  padding: 4px 12px;
  background: rgba(0,0,0,0.75);
  border: 1px solid var(--border);
  border-radius: 6px;
  font-size: 0.75rem;
  color: var(--orange-light);
}

/* ── Download CTA ── */
.download-cta {
  background: linear-gradient(135deg, rgba(255,122,0,0.08) 0%, rgba(168,85,247,0.06) 100%);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 48px 28px;
  text-align: center;
  margin: 48px 0;
}
.download-cta h2 { font-size: 1.5rem; margin-bottom: 12px; }
.download-cta p { color: var(--text-secondary); margin-bottom: 24px; font-size: 0.95rem; }
.btn-primary {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 14px 32px;
  background: linear-gradient(135deg, var(--orange) 0%, #e86500 100%);
  color: #fff;
  font-weight: 600;
  font-size: 1rem;
  border: none;
  border-radius: 12px;
  cursor: pointer;
  transition: transform 0.2s, box-shadow 0.2s;
  box-shadow: 0 4px 20px var(--orange-glow);
}
.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 28px var(--orange-glow);
  color: #fff;
}
.btn-outline {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 12px 24px;
  background: transparent;
  color: var(--orange-light);
  font-weight: 600;
  font-size: 0.92rem;
  border: 1px solid rgba(255,122,0,0.4);
  border-radius: 10px;
  cursor: pointer;
  transition: background 0.2s;
}
.btn-outline:hover { background: rgba(255,122,0,0.08); color: var(--orange); }

/* ── FAQ ── */
.faq-list { display: flex; flex-direction: column; gap: 12px; }
.faq-item {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  overflow: hidden;
}
.faq-q {
  width: 100%;
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 18px 20px;
  background: none;
  border: none;
  color: var(--text-primary);
  font-size: 0.95rem;
  font-weight: 600;
  cursor: pointer;
  text-align: left;
  font-family: var(--font);
}
.faq-q::after {
  content: "+";
  font-size: 1.2rem;
  color: var(--orange);
  flex-shrink: 0;
  margin-left: 12px;
  transition: transform 0.3s;
}
.faq-item.open .faq-q::after { transform: rotate(45deg); }
.faq-a {
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.35s ease;
}
.faq-a-inner {
  padding: 0 20px 18px;
  font-size: 0.88rem;
  color: var(--text-secondary);
  line-height: 1.7;
}

/* ── SEO Text Block ── */
.seo-block {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 36px 28px;
}
.seo-block h2 { font-size: 1.3rem; margin-bottom: 16px; }
.seo-block h3 { font-size: 1.05rem; margin: 24px 0 10px; color: var(--orange-light); }
.seo-block p { font-size: 0.9rem; color: var(--text-secondary); margin-bottom: 12px; }

/* ── Text Columns Module ── */
.text-columns {
  display: grid;
  grid-template-columns: 1fr;
  gap: 20px;
  margin-top: 8px;
}
.text-column-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 28px 24px;
}
.text-column-card h3 {
  font-size: 1.05rem;
  font-weight: 700;
  margin-bottom: 12px;
  color: var(--orange-light);
}
.text-column-card p {
  font-size: 0.88rem;
  color: var(--text-secondary);
  margin-bottom: 10px;
  line-height: 1.7;
}

/* ── Image Showcase Grid ── */
.image-showcase {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 16px;
}
.showcase-item {
  border-radius: var(--radius);
  overflow: hidden;
  border: 1px solid var(--border);
  background: var(--bg-card);
}
.showcase-item img {
  width: 100%;
  aspect-ratio: 9/16;
  object-fit: cover;
  max-height: 280px;
}
.showcase-caption {
  padding: 12px 14px;
  font-size: 0.82rem;
  color: var(--text-secondary);
  line-height: 1.55;
}
.showcase-caption strong {
  display: block;
  color: var(--text-primary);
  font-size: 0.88rem;
  margin-bottom: 4px;
}

/* ── SEO Text Grid ── */
.seo-text-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 20px;
}
.seo-text-card {
  background: var(--bg-elevated);
  border-left: 3px solid var(--orange);
  padding: 20px 24px;
  border-radius: 0 var(--radius) var(--radius) 0;
}
.seo-text-card h3 {
  font-size: 1rem;
  font-weight: 700;
  margin-bottom: 10px;
}
.seo-text-card p {
  font-size: 0.88rem;
  color: var(--text-secondary);
  line-height: 1.7;
}

/* ── Advantage List ── */
.advantage-list {
  counter-reset: adv;
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 16px;
}
.advantage-list li {
  counter-increment: adv;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 20px 20px 20px 56px;
  position: relative;
  font-size: 0.9rem;
  color: var(--text-secondary);
  line-height: 1.65;
}
.advantage-list li::before {
  content: counter(adv);
  position: absolute;
  left: 16px; top: 18px;
  width: 28px; height: 28px;
  background: rgba(255,122,0,0.15);
  color: var(--orange);
  font-weight: 800;
  font-size: 0.85rem;
  border-radius: 8px;
  display: flex;
  align-items: center;
  justify-content: center;
}
.advantage-list li strong {
  display: block;
  color: var(--text-primary);
  font-size: 0.95rem;
  margin-bottom: 6px;
}

/* ── Footer ── */
.site-footer {
  background: var(--bg-card);
  border-top: 1px solid var(--border);
  padding: 48px 0 28px;
  margin-top: 32px;
}
.footer-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 32px;
  margin-bottom: 36px;
}
.footer-brand p { font-size: 0.85rem; color: var(--text-muted); margin-top: 12px; line-height: 1.6; }
.footer-links h4 { font-size: 0.88rem; font-weight: 700; margin-bottom: 14px; color: var(--text-primary); }
.footer-links ul { list-style: none; }
.footer-links li { margin-bottom: 8px; }
.footer-links a { font-size: 0.85rem; color: var(--text-muted); }
.footer-links a:hover { color: var(--orange); }
.footer-bottom {
  border-top: 1px solid rgba(255,255,255,0.06);
  padding-top: 20px;
  text-align: center;
  font-size: 0.8rem;
  color: var(--text-muted);
}

/* ── Sub Pages ── */
.page-hero {
  padding: calc(var(--nav-h) + 40px) 0 32px;
  background: linear-gradient(180deg, rgba(255,122,0,0.06) 0%, transparent 100%);
}
.page-hero h1 { font-size: clamp(1.5rem, 4vw, 2rem); font-weight: 800; margin-bottom: 8px; }
.page-hero p { color: var(--text-secondary); font-size: 0.92rem; }

.breadcrumb {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
  align-items: center;
  font-size: 0.82rem;
  color: var(--text-muted);
  margin-bottom: 16px;
}
.breadcrumb a { color: var(--text-muted); }
.breadcrumb a:hover { color: var(--orange); }
.breadcrumb span { color: var(--text-muted); }

.page-content {
  padding: 40px 0 64px;
}
.legal-content {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 36px 28px;
}
.legal-content h2 { font-size: 1.15rem; margin: 28px 0 12px; color: var(--orange-light); }
.legal-content h2:first-child { margin-top: 0; }
.legal-content p, .legal-content li { font-size: 0.9rem; color: var(--text-secondary); margin-bottom: 10px; }
.legal-content ul, .legal-content ol { padding-left: 20px; margin-bottom: 16px; }

/* ── Error Pages ── */
.error-page {
  min-height: 70vh;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  text-align: center;
  padding: calc(var(--nav-h) + 40px) 5vw 60px;
}
.error-code {
  font-size: clamp(4rem, 15vw, 7rem);
  font-weight: 900;
  background: linear-gradient(135deg, var(--orange), var(--purple));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  line-height: 1;
}
.error-page h1 { font-size: 1.4rem; margin: 16px 0 8px; }
.error-page p { color: var(--text-secondary); font-size: 0.92rem; margin-bottom: 28px; }

/* ── Divider ── */
.section-divider {
  height: 1px;
  background: linear-gradient(90deg, transparent, var(--border), transparent);
  margin: 0;
}

/* ── Desktop ── */
@media (min-width: 768px) {
  .nav-desktop { display: flex; }
  .nav-toggle { display: none; }

  #ads > div, #sticky-ads > div {
    width: calc(12.5% - 8px);
  }

  .hero-grid {
    grid-template-columns: 1fr 1fr;
    gap: 48px;
  }
  .hero-phones { height: 420px; max-width: 100%; }

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

  .features-bento {
    grid-template-columns: repeat(3, 1fr);
  }
  .feature-card.span-2 { grid-column: span 2; }

  .content-block {
    grid-template-columns: 3fr 7fr;
    gap: 40px;
  }
  .content-block.reverse {
    grid-template-columns: 7fr 3fr;
  }
  .content-block.reverse .content-text { order: 1; }
  .content-block.reverse .content-visual { order: 2; }

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

  .legal-content { padding: 48px 56px; }
  .seo-block { padding: 48px 56px; }

  .text-columns { grid-template-columns: repeat(3, 1fr); }
  .image-showcase { grid-template-columns: repeat(4, 1fr); }
  .seo-text-grid { grid-template-columns: repeat(2, 1fr); }
}

@media (min-width: 1024px) {
  .hero { padding: 64px 0 80px; }
  section { padding: 80px 0; }
}