/* 91PO官网 - 午夜紫韵风格 */
:root {
  --bg-deep: #06040c;
  --bg-card: #100c1a;
  --bg-elevated: #161024;
  --border: rgba(217, 70, 239, 0.15);
  --text: #ede8f5;
  --text-muted: #9b8fb8;
  --accent-orange: #ff7a18;
  --accent-magenta: #d946ef;
  --accent-indigo: #6366f1;
  --gradient-brand: linear-gradient(135deg, #ff7a18 0%, #d946ef 50%, #6366f1 100%);
  --gradient-glow: linear-gradient(180deg, rgba(217,70,239,0.12) 0%, transparent 70%);
  --radius: 14px;
  --header-h: 60px;
  --sticky-ads-h: 0px;
  --font-display: "Noto Serif SC", "Songti SC", serif;
  --font-body: "PingFang SC", "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-body);
  background: var(--bg-deep);
  color: var(--text);
  line-height: 1.75;
  overflow-x: hidden;
}

body::before {
  content: "";
  position: fixed;
  inset: 0;
  background:
    radial-gradient(ellipse 60% 40% at 80% 10%, rgba(217,70,239,0.08) 0%, transparent 60%),
    radial-gradient(ellipse 50% 35% at 10% 80%, rgba(255,122,24,0.06) 0%, transparent 55%);
  pointer-events: none;
  z-index: 0;
}

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

.container { width: min(1120px, 92vw); margin: 0 auto; position: relative; z-index: 1; }

/* Header */
.site-header {
  position: fixed;
  top: 0; left: 0; right: 0;
  height: var(--header-h);
  background: rgba(6, 4, 12, 0.88);
  backdrop-filter: blur(16px);
  border-bottom: 1px solid var(--border);
  z-index: 1000;
}

.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);
  font-family: var(--font-display);
  font-size: 1.15rem;
  font-weight: 700;
  letter-spacing: 0.04em;
}

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

.nav-main { display: flex; gap: 28px; }
.nav-main a {
  color: var(--text-muted);
  font-size: 0.92rem;
  position: relative;
  padding: 4px 0;
}
.nav-main a:hover, .nav-main a.active { color: var(--text); }
.nav-main a.active::after {
  content: "";
  position: absolute;
  bottom: -2px; left: 0; right: 0;
  height: 2px;
  background: var(--gradient-brand);
  border-radius: 2px;
}

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

.nav-drawer {
  display: none;
  position: fixed;
  top: var(--header-h);
  left: 0; right: 0;
  background: rgba(10, 7, 18, 0.97);
  backdrop-filter: blur(20px);
  border-bottom: 1px solid var(--border);
  padding: 16px 0;
  z-index: 999;
  flex-direction: column;
}
.nav-drawer.open { display: flex; }
.nav-drawer a {
  padding: 14px 24px;
  color: var(--text-muted);
  border-bottom: 1px solid rgba(255,255,255,0.04);
  font-size: 0.95rem;
}
.nav-drawer a:hover { color: var(--text); background: rgba(217,70,239,0.06); }

/* Sticky Ads Bar */
.ads-sticky-wrap {
  position: fixed;
  top: var(--header-h);
  left: 0; right: 0;
  background: rgba(8, 5, 15, 0.95);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border);
  z-index: 998;
  transform: translateY(-100%);
  opacity: 0;
  transition: transform 0.35s ease, opacity 0.35s ease;
  pointer-events: none;
}
.ads-sticky-wrap.visible {
  transform: translateY(0);
  opacity: 1;
  pointer-events: auto;
}

/* Ads Component */
#ads, #ads-sticky-inner {
  display: flex;
  justify-content: center;
  align-items: flex-start;
  flex-wrap: wrap;
  background: transparent;
  margin: 10px 0;
  gap: 8px;
}

#ads > div, #ads-sticky-inner > div {
  display: flex;
  flex-direction: column;
  align-items: center;
  width: calc(12.5% - 8px);
  min-width: 70px;
  box-sizing: border-box;
}

#ads img, #ads-sticky-inner img {
  width: 65px; height: 65px;
  object-fit: cover;
  border-radius: 18px;
  box-shadow: 0 6px 18px rgba(0,0,0,0.35);
  transition: transform 180ms ease, box-shadow 180ms ease;
  border: 1px solid rgba(217,70,239,0.2);
}

#ads a, #ads-sticky-inner a {
  display: inline-block;
  text-decoration: none;
  border-radius: 15px;
}

#ads img:hover, #ads-sticky-inner img:hover {
  transform: translateY(-4px) scale(1.04);
  box-shadow: 0 10px 24px rgba(217,70,239,0.25);
}

#ads figcaption, #ads .caption,
#ads-sticky-inner figcaption, #ads-sticky-inner .caption {
  height: 15px;
  font-size: 11px;
  color: var(--text-muted);
  text-align: center;
  max-width: 100px;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
  margin-top: 4px;
}

.ads-section {
  padding: calc(var(--header-h) + 16px) 0 8px;
}

.ads-section .ads-label {
  text-align: center;
  font-size: 0.78rem;
  color: var(--text-muted);
  letter-spacing: 0.12em;
  text-transform: uppercase;
  margin-bottom: 4px;
}

/* Hero */
.hero {
  padding: calc(var(--header-h) + 40px) 0 60px;
  position: relative;
  overflow: hidden;
}

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

.hero-text h1 {
  font-family: var(--font-display);
  font-size: clamp(1.8rem, 4.5vw, 2.6rem);
  line-height: 1.3;
  margin-bottom: 20px;
  background: var(--gradient-brand);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.hero-text .lead {
  font-size: 1.05rem;
  color: var(--text-muted);
  margin-bottom: 28px;
  line-height: 1.85;
}

.hero-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-bottom: 24px;
}

.hero-tags span {
  padding: 6px 14px;
  border-radius: 20px;
  font-size: 0.82rem;
  border: 1px solid var(--border);
  background: rgba(217,70,239,0.08);
  color: var(--text-muted);
}

.hero-cta-group { display: flex; gap: 14px; flex-wrap: wrap; }

.btn-primary {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 13px 28px;
  background: var(--gradient-brand);
  color: #fff;
  border: none;
  border-radius: 30px;
  font-size: 0.95rem;
  font-weight: 600;
  cursor: pointer;
  transition: transform 0.2s, box-shadow 0.2s;
  text-decoration: none;
}
.btn-primary:hover { transform: translateY(-2px); box-shadow: 0 8px 28px rgba(217,70,239,0.35); color: #fff; }

.btn-outline {
  display: inline-flex;
  align-items: center;
  padding: 13px 28px;
  border: 1px solid var(--border);
  border-radius: 30px;
  color: var(--text);
  font-size: 0.95rem;
  transition: border-color 0.2s, background 0.2s;
}
.btn-outline:hover { border-color: var(--accent-magenta); background: rgba(217,70,239,0.08); color: var(--text); }

/* Hero 3 overlapping images */
.hero-visual {
  position: relative;
  height: 480px;
  display: flex;
  align-items: center;
  justify-content: center;
}

.hero-stack {
  position: relative;
  width: 240px;
  height: 440px;
}

.hero-stack .stack-item {
  position: absolute;
  width: 200px;
  border-radius: 22px;
  overflow: hidden;
  box-shadow: 0 20px 50px rgba(0,0,0,0.5);
  border: 2px solid rgba(217,70,239,0.25);
  transition: transform 0.4s ease;
}

.hero-stack .stack-item img { width: 100%; height: auto; }

.hero-stack .stack-1 {
  top: 20px; left: 0;
  transform: rotate(-8deg);
  z-index: 1;
  animation: float1 6s ease-in-out infinite;
}

.hero-stack .stack-2 {
  top: 0; left: 50px;
  transform: rotate(3deg);
  z-index: 2;
  animation: float2 5s ease-in-out infinite;
}

.hero-stack .stack-3 {
  top: 40px; left: 100px;
  transform: rotate(10deg);
  z-index: 3;
  animation: float3 7s ease-in-out infinite;
}

@keyframes float1 { 0%,100%{transform:rotate(-8deg) translateY(0)} 50%{transform:rotate(-8deg) translateY(-10px)} }
@keyframes float2 { 0%,100%{transform:rotate(3deg) translateY(0)} 50%{transform:rotate(3deg) translateY(-14px)} }
@keyframes float3 { 0%,100%{transform:rotate(10deg) translateY(0)} 50%{transform:rotate(10deg) translateY(-8px)} }

.hero-glow {
  position: absolute;
  width: 300px; height: 300px;
  background: radial-gradient(circle, rgba(217,70,239,0.2) 0%, transparent 70%);
  border-radius: 50%;
  top: 50%; left: 50%;
  transform: translate(-50%, -50%);
  z-index: 0;
}

/* Sections */
.section { padding: 70px 0; position: relative; }
.section-header { text-align: center; margin-bottom: 48px; }
.section-header h2 {
  font-family: var(--font-display);
  font-size: clamp(1.5rem, 3.5vw, 2rem);
  margin-bottom: 12px;
}
.section-header p { color: var(--text-muted); max-width: 560px; margin: 0 auto; font-size: 0.95rem; }

.section-divider {
  height: 1px;
  background: linear-gradient(90deg, transparent, var(--border), transparent);
  margin: 0 auto 60px;
  max-width: 600px;
}

/* Feature Grid */
.features-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

.feature-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 28px 24px;
  position: relative;
  overflow: hidden;
  transition: transform 0.3s, border-color 0.3s;
}

.feature-card::before {
  content: "";
  position: absolute;
  top: 0; left: 0;
  width: 4px; height: 100%;
  background: var(--gradient-brand);
}

.feature-card:hover { transform: translateY(-4px); border-color: rgba(217,70,239,0.35); }

.feature-card .icon {
  width: 44px; height: 44px;
  border-radius: 12px;
  background: rgba(217,70,239,0.12);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.3rem;
  margin-bottom: 16px;
}

.feature-card h3 { font-size: 1.05rem; margin-bottom: 10px; font-family: var(--font-display); }
.feature-card p { color: var(--text-muted); font-size: 0.9rem; line-height: 1.7; }

/* Content blocks - 3:7 ratio */
.content-block {
  display: grid;
  grid-template-columns: 3fr 7fr;
  gap: 40px;
  align-items: start;
  margin-bottom: 56px;
}

.content-block.reverse { grid-template-columns: 7fr 3fr; }
.content-block.reverse .content-img { order: 2; }

.content-img {
  border-radius: var(--radius);
  overflow: hidden;
  border: 1px solid var(--border);
  box-shadow: 0 12px 40px rgba(0,0,0,0.35);
}

.content-img img { width: 100%; }

.content-text h3 {
  font-family: var(--font-display);
  font-size: 1.3rem;
  margin-bottom: 16px;
  color: var(--text);
}

.content-text p {
  color: var(--text-muted);
  margin-bottom: 14px;
  font-size: 0.93rem;
  text-align: justify;
}

.content-text ul {
  list-style: none;
  margin: 16px 0;
}

.content-text ul li {
  padding: 8px 0 8px 20px;
  position: relative;
  color: var(--text-muted);
  font-size: 0.9rem;
}

.content-text ul li::before {
  content: "◆";
  position: absolute;
  left: 0;
  color: var(--accent-magenta);
  font-size: 0.6rem;
  top: 12px;
}

/* Stats bar */
.stats-bar {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 20px;
  background: var(--bg-elevated);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 32px;
  margin: 48px 0;
}

.stat-item { text-align: center; }
.stat-item .num {
  font-family: var(--font-display);
  font-size: 1.8rem;
  background: var(--gradient-brand);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  font-weight: 700;
}
.stat-item .label { color: var(--text-muted); font-size: 0.85rem; margin-top: 4px; }

/* FAQ */
.faq-list { max-width: 760px; margin: 0 auto; }

.faq-item {
  border: 1px solid var(--border);
  border-radius: var(--radius);
  margin-bottom: 12px;
  background: var(--bg-card);
  overflow: hidden;
}

.faq-q {
  padding: 18px 24px;
  cursor: pointer;
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-weight: 600;
  font-size: 0.95rem;
  transition: background 0.2s;
}

.faq-q:hover { background: rgba(217,70,239,0.06); }
.faq-q::after { content: "+"; font-size: 1.2rem; color: var(--accent-magenta); 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, padding 0.35s ease;
  padding: 0 24px;
  color: var(--text-muted);
  font-size: 0.9rem;
  line-height: 1.75;
}

.faq-item.open .faq-a { max-height: 300px; padding: 0 24px 18px; }

/* Breadcrumb */
.breadcrumb {
  padding: calc(var(--header-h) + 20px) 0 0;
  font-size: 0.85rem;
  color: var(--text-muted);
}

.breadcrumb a { color: var(--text-muted); }
.breadcrumb a:hover { color: var(--accent-magenta); }
.breadcrumb span { margin: 0 8px; opacity: 0.5; }

/* Sub page */
.page-hero {
  padding: 24px 0 40px;
  border-bottom: 1px solid var(--border);
  margin-bottom: 40px;
}

.page-hero h1 {
  font-family: var(--font-display);
  font-size: clamp(1.5rem, 3vw, 2rem);
  margin-bottom: 10px;
}

.page-hero p { color: var(--text-muted); font-size: 0.93rem; }

.page-content {
  padding-bottom: 60px;
}

.page-content h2 {
  font-family: var(--font-display);
  font-size: 1.2rem;
  margin: 32px 0 14px;
  color: var(--text);
}

.page-content h3 { font-size: 1.05rem; margin: 24px 0 10px; }
.page-content p, .page-content li { color: var(--text-muted); font-size: 0.93rem; margin-bottom: 12px; }
.page-content ul, .page-content ol { padding-left: 24px; 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(--header-h) + 40px) 20px 60px;
}

.error-code {
  font-family: var(--font-display);
  font-size: clamp(4rem, 12vw, 7rem);
  background: var(--gradient-brand);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  line-height: 1;
  margin-bottom: 16px;
}

.error-page h1 { font-size: 1.4rem; margin-bottom: 12px; }
.error-page p { color: var(--text-muted); margin-bottom: 28px; max-width: 420px; }

/* Footer */
.site-footer {
  background: var(--bg-card);
  border-top: 1px solid var(--border);
  padding: 48px 0 28px;
  margin-top: 40px;
}

.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr;
  gap: 40px;
  margin-bottom: 36px;
}

.footer-brand p { color: var(--text-muted); font-size: 0.88rem; margin-top: 12px; line-height: 1.7; }

.footer-col h4 {
  font-size: 0.9rem;
  margin-bottom: 16px;
  color: var(--text);
  font-family: var(--font-display);
}

.footer-col a {
  display: block;
  color: var(--text-muted);
  font-size: 0.88rem;
  padding: 5px 0;
  transition: color 0.2s;
}
.footer-col a:hover { color: var(--accent-magenta); }

.footer-bottom {
  border-top: 1px solid var(--border);
  padding-top: 20px;
  text-align: center;
  color: var(--text-muted);
  font-size: 0.82rem;
}

/* Pure text SEO module */
.seo-text-block {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 36px;
  margin-bottom: 40px;
}

.seo-text-block h3 {
  font-family: var(--font-display);
  font-size: 1.15rem;
  margin-bottom: 16px;
}

.seo-text-block p {
  color: var(--text-muted);
  font-size: 0.92rem;
  margin-bottom: 12px;
  text-align: justify;
}

.seo-text-block h4 {
  font-size: 1rem;
  margin: 22px 0 10px;
  color: var(--text);
}

.seo-columns {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 28px;
  margin-bottom: 40px;
}

.seo-columns .seo-text-block { margin-bottom: 0; height: 100%; }

.topic-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
  margin-bottom: 48px;
}

.topic-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 24px 20px;
  transition: border-color 0.3s;
}

.topic-card:hover { border-color: rgba(217,70,239,0.35); }

.topic-card h4 {
  font-family: var(--font-display);
  font-size: 0.98rem;
  margin-bottom: 10px;
  color: var(--accent-orange);
}

.topic-card p {
  color: var(--text-muted);
  font-size: 0.88rem;
  line-height: 1.7;
  text-align: justify;
}

.keyword-bar {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin: 24px 0 40px;
  justify-content: center;
}

.keyword-bar span {
  padding: 8px 16px;
  border-radius: 20px;
  font-size: 0.82rem;
  border: 1px solid var(--border);
  background: rgba(99,102,241,0.08);
  color: var(--text-muted);
}

/* Responsive */
@media (max-width: 900px) {
  .hero-grid { grid-template-columns: 1fr; text-align: center; }
  .hero-visual { height: 380px; order: -1; }
  .hero-cta-group { justify-content: center; }
  .hero-tags { justify-content: center; }
  .features-grid { grid-template-columns: 1fr 1fr; }
  .content-block, .content-block.reverse { grid-template-columns: 1fr; }
  .content-block.reverse .content-img { order: 0; }
  .stats-bar { grid-template-columns: repeat(2, 1fr); }
  .footer-grid { grid-template-columns: 1fr; gap: 28px; }
  .seo-columns { grid-template-columns: 1fr; }
  .topic-grid { grid-template-columns: 1fr 1fr; }
}

@media (max-width: 768px) {
  .nav-main { display: none; }
  .menu-toggle { display: flex; }
  #ads > div, #ads-sticky-inner > div { width: calc(25% - 8px); }
  .features-grid { grid-template-columns: 1fr; }
  .topic-grid { grid-template-columns: 1fr; }
  .hero-stack { width: 200px; height: 360px; }
  .hero-stack .stack-item { width: 160px; }
  .hero-stack .stack-2 { left: 30px; }
  .hero-stack .stack-3 { left: 60px; }
}

@media (min-width: 769px) {
  #ads > div, #ads-sticky-inner > div { width: calc(12.5% - 8px); }
}