/* 91PO Official Site - Original Design */
:root {
  --bg-deep: #0a0a12;
  --bg-card: #12121f;
  --bg-elevated: #1a1a2e;
  --orange: #ff9900;
  --orange-dark: #e68a00;
  --purple: #7c3aed;
  --blue: #3b82f6;
  --gradient-cta: linear-gradient(135deg, #7c3aed 0%, #3b82f6 50%, #ff9900 100%);
  --gradient-subtle: linear-gradient(180deg, rgba(124,58,237,.08) 0%, transparent 100%);
  --text-primary: #f0f0f5;
  --text-secondary: #9ca3b8;
  --text-muted: #6b7280;
  --border: rgba(255,255,255,.06);
  --radius: 14px;
  --radius-sm: 8px;
  --shadow: 0 8px 32px rgba(0,0,0,.45);
  --header-h: 60px;
  --max-w: 1100px;
  --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;
  -webkit-text-size-adjust: 100%;
}

body {
  font-family: var(--font);
  background: var(--bg-deep);
  color: var(--text-primary);
  line-height: 1.75;
  overflow-x: hidden;
}

a { color: var(--orange); text-decoration: none; transition: color .2s; }
a:hover { color: #ffb84d; }

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

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

/* Header */
.site-header {
  position: fixed;
  top: 0; left: 0; right: 0;
  z-index: 1000;
  height: var(--header-h);
  background: rgba(10,10,18,.92);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border-bottom: 1px solid var(--border);
}

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

.brand {
  display: flex;
  align-items: center;
  gap: 10px;
  color: var(--text-primary);
  font-weight: 700;
  font-size: 1.1rem;
}

.brand img { width: 36px; height: 36px; border-radius: 8px; }

.nav-toggle {
  display: flex;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 8px;
}

.nav-toggle span {
  display: block;
  width: 22px;
  height: 2px;
  background: var(--text-primary);
  border-radius: 2px;
  transition: .3s;
}

.nav-toggle.active span:nth-child(1) { transform: rotate(45deg) translate(5px, 5px); }
.nav-toggle.active span:nth-child(2) { opacity: 0; }
.nav-toggle.active span:nth-child(3) { transform: rotate(-45deg) translate(5px, -5px); }

.main-nav {
  position: fixed;
  top: var(--header-h);
  left: 0; right: 0;
  background: rgba(10,10,18,.98);
  padding: 16px 20px 24px;
  transform: translateY(-120%);
  opacity: 0;
  transition: .35s ease;
  border-bottom: 1px solid var(--border);
}

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

.main-nav ul { list-style: none; }
.main-nav li { border-bottom: 1px solid var(--border); }
.main-nav a {
  display: block;
  padding: 14px 0;
  color: var(--text-secondary);
  font-size: .95rem;
}
.main-nav a:hover, .main-nav a.active { color: var(--orange); }

.btn-download-header {
  display: none;
  padding: 8px 20px;
  background: var(--gradient-cta);
  color: #fff !important;
  border-radius: 20px;
  font-size: .85rem;
  font-weight: 600;
}

/* Hero */
.hero {
  padding: 40px 0 56px;
  background: var(--gradient-subtle);
  position: relative;
  overflow: hidden;
}

.hero::before {
  content: "";
  position: absolute;
  top: -40%;
  right: -30%;
  width: 70%;
  height: 120%;
  background: radial-gradient(ellipse, rgba(255,153,0,.12) 0%, transparent 70%);
  pointer-events: none;
}

.hero-grid {
  display: flex;
  flex-direction: column;
  gap: 32px;
  position: relative;
}

.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 6px 14px;
  background: rgba(255,153,0,.12);
  border: 1px solid rgba(255,153,0,.25);
  border-radius: 20px;
  font-size: .8rem;
  color: var(--orange);
  margin-bottom: 16px;
}

.hero h1 {
  font-size: 1.75rem;
  line-height: 1.35;
  font-weight: 800;
  letter-spacing: -.02em;
}

.hero h1 em {
  font-style: normal;
  background: var(--gradient-cta);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.hero-desc {
  color: var(--text-secondary);
  font-size: .95rem;
  margin: 16px 0 24px;
  max-width: 540px;
}

.hero-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-bottom: 28px;
}

.hero-tags span {
  padding: 5px 12px;
  background: var(--bg-elevated);
  border-radius: 6px;
  font-size: .78rem;
  color: var(--text-secondary);
  border: 1px solid var(--border);
}

.hero-cta-group {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.btn-primary {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 15px 32px;
  background: var(--gradient-cta);
  color: #fff;
  border: none;
  border-radius: var(--radius);
  font-size: 1rem;
  font-weight: 700;
  cursor: pointer;
  transition: transform .2s, box-shadow .2s;
  text-align: center;
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 12px 40px rgba(124,58,237,.35);
  color: #fff;
}

.btn-secondary {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 13px 28px;
  background: transparent;
  color: var(--text-primary);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  font-size: .9rem;
  transition: border-color .2s;
}

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

.hero-visual {
  display: flex;
  justify-content: center;
}

.phone-mockup {
  width: 240px;
  border-radius: 28px;
  border: 3px solid rgba(255,255,255,.08);
  box-shadow: var(--shadow), 0 0 60px rgba(124,58,237,.15);
  overflow: hidden;
  background: #000;
}

/* Stats */
.stats-bar {
  padding: 32px 0;
  border-top: 1px solid var(--border);
  border-bottom: 1px solid var(--border);
  background: var(--bg-card);
}

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

.stat-item strong {
  display: block;
  font-size: 1.5rem;
  font-weight: 800;
  color: var(--orange);
  line-height: 1.2;
}

.stat-item span {
  font-size: .78rem;
  color: var(--text-muted);
  margin-top: 4px;
  display: block;
}

/* Sections */
.section {
  padding: 56px 0;
}

.section-label {
  display: inline-block;
  font-size: .75rem;
  text-transform: uppercase;
  letter-spacing: .12em;
  color: var(--purple);
  margin-bottom: 10px;
  font-weight: 600;
}

.section-title {
  font-size: 1.5rem;
  font-weight: 800;
  margin-bottom: 12px;
  line-height: 1.3;
}

.section-desc {
  color: var(--text-secondary);
  font-size: .92rem;
  margin-bottom: 32px;
  max-width: 640px;
}

/* Content block 3:7 ratio */
.content-block {
  display: flex;
  flex-direction: column;
  gap: 24px;
  margin-bottom: 48px;
}

.content-block.reverse .content-media { order: -1; }

.content-media {
  flex: 0 0 30%;
  max-width: 100%;
}

.content-media img {
  border-radius: var(--radius);
  border: 1px solid var(--border);
  box-shadow: var(--shadow);
}

.content-text {
  flex: 1;
}

.content-text h3 {
  font-size: 1.15rem;
  margin-bottom: 12px;
  color: var(--text-primary);
}

.content-text p {
  color: var(--text-secondary);
  font-size: .9rem;
  margin-bottom: 12px;
}

.content-text ul {
  list-style: none;
  margin: 12px 0;
}

.content-text li {
  position: relative;
  padding-left: 18px;
  color: var(--text-secondary);
  font-size: .88rem;
  margin-bottom: 8px;
}

.content-text li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 10px;
  width: 6px;
  height: 6px;
  background: var(--orange);
  border-radius: 50%;
}

/* Features grid */
.features-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 16px;
}

.feature-card {
  padding: 24px;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  transition: border-color .3s, transform .3s;
}

.feature-card:hover {
  border-color: rgba(255,153,0,.2);
  transform: translateY(-3px);
}

.feature-icon {
  width: 44px;
  height: 44px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: rgba(124,58,237,.15);
  border-radius: 10px;
  font-size: 1.3rem;
  margin-bottom: 14px;
}

.feature-card h3 {
  font-size: 1rem;
  margin-bottom: 8px;
}

.feature-card p {
  font-size: .85rem;
  color: var(--text-secondary);
  line-height: 1.65;
}

/* Preview gallery */
.preview-tabs {
  display: flex;
  gap: 8px;
  overflow-x: auto;
  padding-bottom: 8px;
  margin-bottom: 20px;
  -webkit-overflow-scrolling: touch;
}

.preview-tab {
  flex-shrink: 0;
  padding: 8px 16px;
  background: var(--bg-elevated);
  border: 1px solid var(--border);
  border-radius: 20px;
  font-size: .8rem;
  color: var(--text-secondary);
  cursor: pointer;
  transition: .2s;
}

.preview-tab.active {
  background: rgba(255,153,0,.15);
  border-color: rgba(255,153,0,.4);
  color: var(--orange);
}

.preview-showcase {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 12px;
}

.preview-item {
  border-radius: var(--radius-sm);
  overflow: hidden;
  border: 1px solid var(--border);
  position: relative;
}

.preview-item img { width: 100%; aspect-ratio: 9/16; object-fit: cover; }

.preview-item span {
  position: absolute;
  bottom: 0; left: 0; right: 0;
  padding: 8px;
  background: linear-gradient(transparent, rgba(0,0,0,.8));
  font-size: .72rem;
  color: #fff;
}

/* 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%;
  padding: 18px 20px;
  background: none;
  border: none;
  color: var(--text-primary);
  font-size: .92rem;
  font-weight: 600;
  text-align: left;
  cursor: pointer;
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-family: var(--font);
}

.faq-q::after {
  content: "+";
  font-size: 1.2rem;
  color: var(--orange);
  transition: transform .3s;
}

.faq-item.open .faq-q::after { transform: rotate(45deg); }

.faq-a {
  max-height: 0;
  overflow: hidden;
  transition: max-height .35s ease;
}

.faq-a-inner {
  padding: 0 20px 18px;
  color: var(--text-secondary);
  font-size: .88rem;
}

.faq-item.open .faq-a { max-height: 500px; }

/* CTA Banner */
.cta-banner {
  padding: 48px 24px;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  text-align: center;
  margin: 0 0 56px;
}

.cta-banner h2 {
  font-size: 1.35rem;
  margin-bottom: 10px;
}

.cta-banner p {
  color: var(--text-secondary);
  font-size: .9rem;
  margin-bottom: 24px;
}

/* Footer */
.site-footer {
  padding: 40px 0 24px;
  background: var(--bg-card);
  border-top: 1px solid var(--border);
}

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

.footer-brand img { width: 40px; border-radius: 8px; margin-bottom: 12px; }

.footer-brand p {
  font-size: .82rem;
  color: var(--text-muted);
  line-height: 1.6;
}

.footer-links h4 {
  font-size: .85rem;
  margin-bottom: 12px;
  color: var(--text-primary);
}

.footer-links ul { list-style: none; }
.footer-links li { margin-bottom: 8px; }
.footer-links a {
  font-size: .82rem;
  color: var(--text-muted);
}
.footer-links a:hover { color: var(--orange); }

.footer-bottom {
  padding-top: 20px;
  border-top: 1px solid var(--border);
  text-align: center;
  font-size: .75rem;
  color: var(--text-muted);
}

/* Breadcrumb */
.breadcrumb {
  padding: 20px 0 0;
  font-size: .8rem;
  color: var(--text-muted);
}

.breadcrumb a { color: var(--text-secondary); }
.breadcrumb span { margin: 0 6px; }

/* Subpage */
.page-hero {
  padding: 24px 0 32px;
}

.page-hero h1 {
  font-size: 1.5rem;
  font-weight: 800;
}

.page-content {
  padding-bottom: 56px;
}

.page-content h2 {
  font-size: 1.1rem;
  margin: 28px 0 12px;
  color: var(--text-primary);
}

.page-content h3 {
  font-size: 1rem;
  margin: 20px 0 10px;
  color: var(--text-secondary);
}

.page-content p, .page-content li {
  color: var(--text-secondary);
  font-size: .9rem;
  margin-bottom: 12px;
}

.page-content ul, .page-content ol {
  padding-left: 20px;
  margin-bottom: 16px;
}

.page-content li { margin-bottom: 6px; }

/* Error pages */
.error-page {
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  text-align: center;
  padding: 40px 20px;
}

.error-code {
  font-size: 5rem;
  font-weight: 900;
  background: var(--gradient-cta);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  line-height: 1;
}

.error-page h1 { font-size: 1.3rem; margin: 16px 0 8px; }
.error-page p { color: var(--text-secondary); font-size: .9rem; margin-bottom: 24px; }

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

  .main-nav {
    position: static;
    transform: none;
    opacity: 1;
    background: none;
    padding: 0;
    border: none;
    display: flex;
    align-items: center;
    gap: 24px;
  }

  .main-nav ul { display: flex; gap: 4px; }
  .main-nav li { border: none; }
  .main-nav a { padding: 8px 14px; font-size: .85rem; }

  .btn-download-header { display: inline-flex; }

  .hero-grid {
    flex-direction: row;
    align-items: center;
  }

  .hero-content { flex: 1; }
  .hero-visual { flex: 0 0 auto; }

  .hero h1 { font-size: 2.4rem; }

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

  .content-block {
    flex-direction: row;
    align-items: flex-start;
    gap: 32px;
  }

  .content-block.reverse { flex-direction: row-reverse; }

  .content-media { flex: 0 0 30%; max-width: 30%; }

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

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

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

@media (min-width: 1024px) {
  .features-grid { grid-template-columns: repeat(3, 1fr); }
  .hero h1 { font-size: 2.8rem; }
  .phone-mockup { width: 280px; }
}

/* Ads download area */
.ads-top-section {
  padding: calc(var(--header-h) + 16px) 0 20px;
  background: var(--bg-card);
  border-bottom: 1px solid var(--border);
}

.ads-top-label {
  text-align: center;
  font-size: .82rem;
  color: var(--text-muted);
  margin-bottom: 14px;
  letter-spacing: .04em;
}

.ads-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 14px 10px;
  justify-items: center;
}

@media (min-width: 768px) {
  .ads-top-section .ads-grid {
    grid-template-columns: repeat(8, 1fr);
    gap: 14px 8px;
  }

  .ads-top-section .ads-item {
    max-width: 72px;
  }
}

.ads-item {
  display: flex;
  flex-direction: column;
  align-items: center;
  width: 100%;
  max-width: 80px;
}

.ads-item figure {
  margin: 0;
  display: flex;
  flex-direction: column;
  align-items: center;
  width: 100%;
}

.ads-item a {
  display: block;
  border-radius: 15px;
  line-height: 0;
}

.ads-item img {
  width: 65px;
  height: 65px;
  object-fit: cover;
  border-radius: 18px;
  box-shadow: 0 6px 18px rgba(0,0,0,.35);
  transition: transform .18s ease, box-shadow .18s ease;
  border: 1px solid var(--border);
  background: var(--bg-elevated);
}

.ads-item img:hover {
  transform: translateY(-4px) scale(1.04);
  box-shadow: 0 10px 24px rgba(124,58,237,.25);
}

.ads-caption {
  margin-top: 6px;
  font-size: 11px;
  color: var(--text-muted);
  text-align: center;
  max-width: 76px;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
  line-height: 1.3;
}

/* Sticky ads bar — mobile: fixed bottom; PC: fixed below header */
.ads-sticky-bar {
  position: fixed;
  left: 0;
  right: 0;
  bottom: 0;
  top: auto;
  z-index: 999;
  background: rgba(10,10,18,.97);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-top: 1px solid var(--border);
  padding: 10px 0;
  padding-bottom: max(10px, env(safe-area-inset-bottom));
  transform: translateY(110%);
  opacity: 0;
  pointer-events: none;
  transition: transform .3s ease, opacity .3s ease;
}

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

.ads-sticky-bar .ads-grid {
  grid-template-columns: repeat(4, 1fr);
  gap: 8px 6px;
}

.ads-sticky-bar .ads-item {
  max-width: 72px;
}

.ads-sticky-bar .ads-item img {
  width: 52px;
  height: 52px;
  border-radius: 14px;
}

.ads-sticky-bar .ads-caption {
  font-size: 10px;
  max-width: 64px;
}

body.has-sticky-ads {
  padding-bottom: 88px;
}

@media (min-width: 768px) {
  .ads-sticky-bar {
    top: var(--header-h);
    bottom: auto;
    border-top: none;
    border-bottom: 1px solid var(--border);
    padding-bottom: 10px;
    transform: translateY(-110%);
  }

  .ads-sticky-bar.visible {
    transform: translateY(0);
  }

  .ads-sticky-bar .ads-grid {
    grid-template-columns: repeat(8, 1fr);
    gap: 10px 6px;
  }

  .ads-sticky-bar .ads-item {
    max-width: 68px;
  }

  .ads-sticky-bar .ads-item img {
    width: 48px;
    height: 48px;
    border-radius: 12px;
  }

  .ads-sticky-bar .ads-caption {
    font-size: 10px;
    max-width: 56px;
  }

  body.has-sticky-ads {
    padding-bottom: 0;
  }
}

/* Text-only SEO blocks */
.seo-text-block {
  padding: 28px;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  margin-bottom: 32px;
}

.seo-text-block h3 {
  font-size: 1.1rem;
  margin-bottom: 14px;
  color: var(--text-primary);
}

.seo-text-block p {
  color: var(--text-secondary);
  font-size: .9rem;
  margin-bottom: 12px;
}

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

/* 404 with ads layout */
.error-page-wrap {
  padding: 40px 0 56px;
}

.error-page-wrap .error-page {
  min-height: auto;
  padding: 32px 0;
}