/* 91PO视频官网 — 绯夜绸缎视觉体系 */
:root {
  --ink: #060508;
  --velvet: #110a10;
  --velvet-mid: #1a1018;
  --velvet-card: #221420;
  --wine: #8b1a3a;
  --wine-deep: #5c0f28;
  --wine-glow: #c42d5a;
  --amber: #e8a317;
  --amber-soft: #f5c842;
  --blush: #d4899a;
  --blush-pale: #f0b8c8;
  --teal: #2dd4bf;
  --pearl: #f3ece8;
  --pearl-dim: #b8a8ae;
  --pearl-faint: #7a6b72;
  --border-wine: rgba(139, 26, 58, 0.35);
  --border-amber: rgba(232, 163, 23, 0.25);
  --grad-hero: linear-gradient(155deg, #1a0812 0%, #0a0608 50%, #120a14 100%);
  --grad-cta: linear-gradient(110deg, var(--wine) 0%, var(--wine-glow) 45%, var(--amber) 100%);
  --grad-sheen: linear-gradient(180deg, rgba(232,163,23,0.06) 0%, transparent 60%);
  --shadow-warm: 0 24px 80px rgba(139, 26, 58, 0.18);
  --radius: 16px;
  --nav-h: 56px;
  font-size: 16px;
}

*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; }

body {
  font-family: "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  background: var(--ink);
  color: var(--pearl);
  line-height: 1.9;
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
}

body::after {
  content: "";
  position: fixed;
  inset: 0;
  background:
    radial-gradient(ellipse 55% 45% at 10% 5%, rgba(139, 26, 58, 0.14), transparent),
    radial-gradient(ellipse 40% 35% at 95% 90%, rgba(232, 163, 23, 0.08), transparent),
    radial-gradient(ellipse 25% 20% at 60% 40%, rgba(45, 212, 191, 0.04), transparent);
  pointer-events: none;
  z-index: 0;
}

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

.wrap {
  width: min(1080px, 92vw);
  margin: 0 auto;
  position: relative;
  z-index: 1;
}

/* ===== 顶栏 ===== */
.site-header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: var(--nav-h);
  z-index: 300;
  background: rgba(6, 5, 8, 0.94);
  backdrop-filter: blur(18px);
  border-bottom: 1px solid var(--border-wine);
}

.header-row {
  width: min(1080px, 92vw);
  margin: 0 auto;
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
}

.logo-link {
  display: flex;
  align-items: center;
  gap: 9px;
  color: var(--pearl);
  font-weight: 700;
  font-size: 1.05rem;
  letter-spacing: 0.06em;
}

.logo-link img {
  width: 34px;
  height: 34px;
  border-radius: 9px;
}

.nav-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 6px;
}

.nav-toggle span {
  display: block;
  width: 22px;
  height: 2px;
  background: var(--pearl);
  border-radius: 2px;
  transition: transform 0.25s;
}

.main-nav {
  display: flex;
  gap: 6px;
  align-items: center;
}

.main-nav a {
  padding: 7px 14px;
  font-size: 0.88rem;
  color: var(--pearl-dim);
  border-radius: 8px;
  transition: background 0.2s, color 0.2s;
}

.main-nav a:hover,
.main-nav a.active {
  color: var(--pearl);
  background: rgba(139, 26, 58, 0.2);
}

.nav-dl-btn {
  padding: 8px 18px !important;
  background: var(--grad-cta) !important;
  color: #fff !important;
  font-weight: 600;
  border-radius: 20px !important;
}

.nav-dl-btn:hover { opacity: 0.9; color: #fff !important; }

/* ===== 粘性下载栏 ===== */
.pin-dl-strip {
  position: fixed;
  top: var(--nav-h);
  left: 0;
  right: 0;
  z-index: 250;
  background: rgba(17, 10, 16, 0.97);
  border-bottom: 1px solid var(--border-wine);
  padding: 8px 0;
  transform: translateY(-110%);
  opacity: 0;
  transition: transform 0.3s, opacity 0.3s;
  pointer-events: none;
}

.pin-dl-strip.visible {
  transform: translateY(0);
  opacity: 1;
  pointer-events: auto;
}

body.has-pin-ads { padding-top: calc(var(--nav-h) + var(--pin-h, 0px)); }
body.has-pin-ads .pin-dl-strip.visible ~ .page-body .site-header { }

/* ===== 广告位 ===== */
#ads,
#sticky-ads {
  display: flex;
  justify-content: center;
  align-items: flex-start;
  flex-wrap: wrap;
  background: transparent;
  gap: 8px 6px;
}

#ads > div,
#sticky-ads > div {
  display: flex;
  flex-direction: column;
  align-items: center;
  width: calc(12.5% - 6px);
  box-sizing: border-box;
}

#ads img,
#sticky-ads img {
  width: 58px;
  height: 58px;
  object-fit: cover;
  border-radius: 14px;
  box-shadow: 0 4px 16px rgba(0, 0, 0, 0.35);
  transition: transform 0.18s, box-shadow 0.18s;
  border: 1px solid var(--border-wine);
}

#ads a,
#sticky-ads a {
  display: inline-block;
  text-decoration: none;
  border-radius: 14px;
}

#ads img:hover,
#sticky-ads img:hover {
  transform: translateY(-3px) scale(1.05);
  box-shadow: 0 8px 22px rgba(139, 26, 58, 0.3);
}

#ads figcaption,
#ads .caption,
#sticky-ads figcaption,
#sticky-ads .caption {
  height: 15px;
  font-size: 10px;
  color: var(--pearl-faint);
  text-align: center;
  max-width: 72px;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
  margin-top: 3px;
}

@media (max-width: 768px) {
  #ads > div,
  #sticky-ads > div {
    width: calc(25% - 6px);
  }
  #ads img,
  #sticky-ads img {
    width: 52px;
    height: 52px;
  }
}

/* ===== 下载区 ===== */
.dl-hero-block {
  padding: calc(var(--nav-h) + 20px) 0 28px;
  background: var(--grad-hero);
  border-bottom: 1px solid var(--border-wine);
}

.dl-hero-block .dl-label {
  text-align: center;
  font-size: 0.78rem;
  letter-spacing: 0.2em;
  color: var(--amber);
  text-transform: uppercase;
  margin-bottom: 12px;
}

/* ===== 首屏 ===== */
.intro-banner {
  padding: 48px 0 56px;
  position: relative;
}

.intro-banner::before {
  content: "";
  position: absolute;
  top: 0;
  left: 50%;
  transform: translateX(-50%);
  width: 1px;
  height: 60px;
  background: linear-gradient(180deg, var(--wine-glow), transparent);
}

.intro-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 36px;
  align-items: center;
}

.intro-copy h1 {
  font-family: Georgia, "Noto Serif SC", serif;
  font-size: clamp(1.6rem, 5vw, 2.35rem);
  font-weight: 700;
  line-height: 1.35;
  color: var(--pearl);
  margin-bottom: 18px;
}

.intro-copy h1 em {
  display: block;
  font-style: normal;
  font-size: 0.55em;
  font-weight: 400;
  color: var(--blush);
  margin-top: 10px;
  letter-spacing: 0.04em;
}

.intro-lead {
  font-size: 1.02rem;
  color: var(--pearl-dim);
  margin-bottom: 22px;
}

.intro-badges {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.intro-badges span {
  padding: 5px 14px;
  font-size: 0.78rem;
  border: 1px solid var(--border-wine);
  border-radius: 20px;
  color: var(--blush-pale);
  background: rgba(139, 26, 58, 0.1);
}

.intro-cta-row {
  margin-top: 26px;
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}

.btn-primary {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 13px 28px;
  background: var(--grad-cta);
  color: #fff;
  font-weight: 600;
  font-size: 0.95rem;
  border-radius: 28px;
  border: none;
  cursor: pointer;
  transition: transform 0.2s, box-shadow 0.2s;
  box-shadow: var(--shadow-warm);
}

.btn-primary:hover {
  transform: translateY(-2px);
  color: #fff;
  box-shadow: 0 16px 40px rgba(139, 26, 58, 0.35);
}

.btn-outline {
  display: inline-flex;
  align-items: center;
  padding: 12px 24px;
  border: 1px solid var(--border-amber);
  color: var(--amber-soft);
  border-radius: 28px;
  font-size: 0.9rem;
  transition: background 0.2s;
}

.btn-outline:hover {
  background: rgba(232, 163, 23, 0.1);
  color: var(--amber-soft);
}

.intro-visual {
  display: flex;
  justify-content: center;
  gap: 14px;
  perspective: 800px;
}

.phone-frame {
  width: 148px;
  border-radius: 22px;
  overflow: hidden;
  border: 2px solid var(--border-wine);
  box-shadow: var(--shadow-warm);
  transition: transform 0.35s;
}

.phone-frame:nth-child(2) { transform: translateY(-16px) scale(1.05); }
.phone-frame:nth-child(1),
.phone-frame:nth-child(3) { opacity: 0.85; transform: scale(0.92); }

@media (min-width: 768px) {
  .intro-grid {
    grid-template-columns: 1.1fr 0.9fr;
  }
  .phone-frame { width: 168px; }
}

/* ===== 数据条 ===== */
.metric-strip {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 12px;
  margin-bottom: 52px;
}

@media (min-width: 600px) {
  .metric-strip { grid-template-columns: repeat(4, 1fr); }
}

.metric-item {
  text-align: center;
  padding: 20px 12px;
  background: var(--velvet-card);
  border-radius: var(--radius);
  border: 1px solid var(--border-wine);
}

.metric-item strong {
  display: block;
  font-size: 1.5rem;
  color: var(--amber);
  font-weight: 700;
  margin-bottom: 4px;
}

.metric-item span {
  font-size: 0.8rem;
  color: var(--pearl-faint);
}

/* ===== 内容区块 ===== */
.content-main { padding-bottom: 64px; }

.section-head {
  margin-bottom: 32px;
  padding-bottom: 16px;
  border-bottom: 1px solid var(--border-wine);
}

.section-head h2 {
  font-family: Georgia, "Noto Serif SC", serif;
  font-size: clamp(1.3rem, 3.5vw, 1.75rem);
  color: var(--pearl);
  margin-bottom: 8px;
}

.section-head p {
  color: var(--pearl-faint);
  font-size: 0.92rem;
}

/* 3:7 图文比例 */
.ratio-block {
  display: grid;
  grid-template-columns: 1fr;
  gap: 24px;
  margin-bottom: 48px;
  align-items: start;
}

.ratio-block .ratio-img {
  position: relative;
}

.ratio-block .ratio-img img {
  border-radius: var(--radius);
  border: 1px solid var(--border-wine);
  box-shadow: var(--shadow-warm);
  width: 100%;
  max-width: 280px;
  margin: 0 auto;
}

.ratio-block .ratio-img::after {
  content: "";
  position: absolute;
  bottom: -8px;
  right: -8px;
  width: 60%;
  height: 60%;
  border: 1px solid var(--border-amber);
  border-radius: var(--radius);
  z-index: -1;
}

.ratio-block .ratio-text h3 {
  font-size: 1.15rem;
  color: var(--blush-pale);
  margin-bottom: 12px;
}

.ratio-block .ratio-text p {
  color: var(--pearl-dim);
  font-size: 0.95rem;
  margin-bottom: 14px;
}

.ratio-block .ratio-text ul {
  list-style: none;
  padding: 0;
}

.ratio-block .ratio-text li {
  position: relative;
  padding-left: 18px;
  margin-bottom: 8px;
  font-size: 0.9rem;
  color: var(--pearl-dim);
}

.ratio-block .ratio-text li::before {
  content: "◆";
  position: absolute;
  left: 0;
  color: var(--wine-glow);
  font-size: 0.55rem;
  top: 6px;
}

@media (min-width: 768px) {
  .ratio-block {
    grid-template-columns: 3fr 7fr;
    gap: 32px;
  }
  .ratio-block.flip {
    grid-template-columns: 7fr 3fr;
  }
  .ratio-block.flip .ratio-img { order: 2; }
  .ratio-block.flip .ratio-text { order: 1; }
  .ratio-block .ratio-img img { max-width: 100%; }
}

/* 功能卡片 */
.feature-deck {
  display: grid;
  grid-template-columns: 1fr;
  gap: 16px;
  margin-bottom: 48px;
}

@media (min-width: 600px) {
  .feature-deck { grid-template-columns: repeat(2, 1fr); }
}

@media (min-width: 900px) {
  .feature-deck { grid-template-columns: repeat(3, 1fr); }
}

.feature-tile {
  padding: 24px 20px;
  background: var(--velvet-card);
  border-radius: var(--radius);
  border: 1px solid var(--border-wine);
  transition: border-color 0.25s, transform 0.25s;
}

.feature-tile:hover {
  border-color: var(--wine-glow);
  transform: translateY(-3px);
}

.feature-tile .tile-icon {
  font-size: 1.4rem;
  margin-bottom: 10px;
}

.feature-tile h4 {
  font-size: 1rem;
  color: var(--pearl);
  margin-bottom: 8px;
}

.feature-tile p {
  font-size: 0.86rem;
  color: var(--pearl-faint);
  line-height: 1.7;
}

/* FAQ */
.faq-list { margin-bottom: 48px; }

.faq-item {
  border-bottom: 1px solid var(--border-wine);
  padding: 18px 0;
}

.faq-item h4 {
  font-size: 0.98rem;
  color: var(--blush-pale);
  margin-bottom: 8px;
}

.faq-item p {
  font-size: 0.9rem;
  color: var(--pearl-dim);
}

/* 内链区 */
.link-hub {
  padding: 32px;
  background: var(--velvet-mid);
  border-radius: var(--radius);
  border: 1px solid var(--border-wine);
  margin-bottom: 40px;
}

.link-hub h3 {
  font-size: 1.05rem;
  margin-bottom: 14px;
  color: var(--amber);
}

.link-hub nav {
  display: flex;
  flex-wrap: wrap;
  gap: 10px 20px;
}

.link-hub nav a {
  font-size: 0.88rem;
  color: var(--pearl-dim);
}

/* ===== 页脚 ===== */
.site-footer {
  padding: 40px 0 32px;
  border-top: 1px solid var(--border-wine);
  background: var(--velvet);
  text-align: center;
}

.footer-brand {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  margin-bottom: 16px;
}

.footer-brand img { width: 32px; height: 32px; border-radius: 8px; }
.footer-brand span { font-weight: 600; color: var(--pearl); }

.footer-nav {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 8px 18px;
  margin-bottom: 16px;
}

.footer-nav a {
  font-size: 0.84rem;
  color: var(--pearl-faint);
}

.footer-copy {
  font-size: 0.78rem;
  color: var(--pearl-faint);
  opacity: 0.7;
}

/* ===== 子页面 ===== */
.page-body { padding-top: var(--nav-h); min-height: 100vh; }

.sub-hero {
  padding: 40px 0 28px;
  background: var(--grad-hero);
  border-bottom: 1px solid var(--border-wine);
}

.sub-hero h1 {
  font-family: Georgia, "Noto Serif SC", serif;
  font-size: clamp(1.4rem, 4vw, 2rem);
  color: var(--pearl);
  margin-bottom: 8px;
}

.breadcrumb {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
  font-size: 0.82rem;
  color: var(--pearl-faint);
  margin-bottom: 12px;
}

.breadcrumb a { color: var(--pearl-dim); }
.breadcrumb span.sep { opacity: 0.4; }

.sub-content {
  padding: 40px 0 64px;
}

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

.sub-content h2:first-child { margin-top: 0; }

.sub-content p,
.sub-content li {
  font-size: 0.92rem;
  color: var(--pearl-dim);
  margin-bottom: 12px;
}

.sub-content ul,
.sub-content ol {
  padding-left: 22px;
  margin-bottom: 16px;
}

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

/* ===== 错误页 ===== */
.error-page {
  min-height: calc(100vh - var(--nav-h));
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  text-align: center;
  padding: 40px 20px;
}

.error-code {
  font-size: clamp(4rem, 15vw, 7rem);
  font-weight: 700;
  background: var(--grad-cta);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  line-height: 1;
  margin-bottom: 16px;
}

.error-page h1 {
  font-size: 1.3rem;
  color: var(--pearl);
  margin-bottom: 12px;
}

.error-page p {
  color: var(--pearl-dim);
  margin-bottom: 24px;
  max-width: 420px;
}

.error-actions {
  display: flex;
  gap: 12px;
  flex-wrap: wrap;
  justify-content: center;
}

/* ===== 移动端导航 ===== */
@media (max-width: 768px) {
  .nav-toggle { display: flex; }

  .main-nav {
    position: fixed;
    top: var(--nav-h);
    left: 0;
    right: 0;
    background: rgba(17, 10, 16, 0.98);
    flex-direction: column;
    padding: 16px;
    gap: 4px;
    border-bottom: 1px solid var(--border-wine);
    transform: translateY(-120%);
    opacity: 0;
    transition: transform 0.3s, opacity 0.3s;
    z-index: 290;
  }

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

  .main-nav a {
    width: 100%;
    text-align: center;
    padding: 12px;
  }

  .intro-visual { gap: 8px; }
  .phone-frame { width: 100px; }
  .phone-frame:nth-child(3) { display: none; }

  .main-nav .nav-dl-btn { display: none !important; }
}

/* ===== 纯文案 SEO 模块 ===== */
.prose-block {
  margin-bottom: 48px;
  padding: 32px 28px;
  background: var(--velvet-mid);
  border-radius: var(--radius);
  border: 1px solid var(--border-wine);
}

.prose-block h2 {
  font-family: Georgia, "Noto Serif SC", serif;
  font-size: clamp(1.2rem, 3vw, 1.55rem);
  color: var(--pearl);
  margin-bottom: 16px;
}

.prose-block h3 {
  font-size: 1.02rem;
  color: var(--blush-pale);
  margin: 22px 0 10px;
}

.prose-block p {
  font-size: 0.94rem;
  color: var(--pearl-dim);
  margin-bottom: 14px;
}

.prose-block ul {
  list-style: none;
  padding: 0;
  margin-bottom: 14px;
}

.prose-block li {
  position: relative;
  padding-left: 18px;
  margin-bottom: 8px;
  font-size: 0.9rem;
  color: var(--pearl-dim);
}

.prose-block li::before {
  content: "—";
  position: absolute;
  left: 0;
  color: var(--amber);
}

.img-duo {
  display: grid;
  grid-template-columns: 1fr;
  gap: 16px;
  margin: 20px 0;
}

@media (min-width: 600px) {
  .img-duo { grid-template-columns: 1fr 1fr; }
}

.img-duo figure {
  border-radius: var(--radius);
  overflow: hidden;
  border: 1px solid var(--border-wine);
}

.img-duo figcaption {
  padding: 10px 12px;
  font-size: 0.78rem;
  color: var(--pearl-faint);
  background: var(--velvet-card);
  text-align: center;
}