/* 91PO传媒官网 — Amber Noir 原创视觉体系 */
:root {
  --ink: #060608;
  --ink-soft: #0e0e12;
  --surface: #141418;
  --surface-2: #1c1c22;
  --amber: #ff8a00;
  --amber-bright: #ffb020;
  --amber-dim: rgba(255, 138, 0, 0.12);
  --gold: #ffd166;
  --text: #ececf0;
  --text-dim: #9898a8;
  --text-faint: #5c5c6e;
  --line: rgba(255, 255, 255, 0.07);
  --line-amber: rgba(255, 138, 0, 0.35);
  --header-h: 58px;
  --radius: 16px;
  --radius-sm: 10px;
  --max: 1080px;
  --font: "PingFang SC", "Microsoft YaHei", "Helvetica Neue", sans-serif;
  --font-display: "Segoe UI", "PingFang SC", sans-serif;
}

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

html { scroll-behavior: smooth; -webkit-text-size-adjust: 100%; }

body {
  font-family: var(--font);
  background: var(--ink);
  color: var(--text);
  line-height: 1.8;
  font-size: 15px;
  overflow-x: hidden;
}

body.has-sticky-ads { padding-bottom: 96px; }
body.has-sticky-ads-pc { padding-top: 0; }

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

a { color: var(--amber-bright); text-decoration: none; transition: color 0.2s; }
a:hover { color: var(--gold); }

.container { width: 100%; max-width: var(--max); margin: 0 auto; padding: 0 18px; }

/* ===== Header ===== */
.site-header {
  position: fixed;
  top: 0; left: 0; right: 0;
  z-index: 1000;
  height: var(--header-h);
  background: rgba(6, 6, 8, 0.88);
  backdrop-filter: blur(18px);
  -webkit-backdrop-filter: blur(18px);
  border-bottom: 1px solid var(--line);
}

.site-header.scrolled { box-shadow: 0 6px 32px rgba(0, 0, 0, 0.55); }

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: var(--header-h);
  max-width: var(--max);
  margin: 0 auto;
  padding: 0 18px;
}

.brand {
  display: flex;
  align-items: center;
  gap: 10px;
  color: var(--text);
  font-weight: 700;
  font-size: 16px;
  letter-spacing: 0.04em;
}

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

.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);
  border-radius: 2px;
  transition: transform 0.3s, opacity 0.3s;
}

.nav-toggle.active span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
.nav-toggle.active span:nth-child(2) { opacity: 0; }
.nav-toggle.active span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

.main-nav {
  position: fixed;
  top: var(--header-h);
  left: 0; right: 0;
  background: rgba(6, 6, 8, 0.97);
  border-bottom: 1px solid var(--line);
  padding: 16px 18px 24px;
  transform: translateY(-110%);
  opacity: 0;
  pointer-events: none;
  transition: transform 0.35s, opacity 0.35s;
  z-index: 999;
}

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

.main-nav a {
  display: block;
  padding: 12px 0;
  color: var(--text-dim);
  font-size: 15px;
  border-bottom: 1px solid var(--line);
}

.main-nav a:hover, .main-nav a.active { color: var(--amber); }

@media (min-width: 768px) {
  .nav-toggle { display: none; }
  .main-nav {
    position: static;
    display: flex;
    gap: 28px;
    padding: 0;
    background: none;
    border: none;
    transform: none;
    opacity: 1;
    pointer-events: auto;
  }
  .main-nav a { padding: 0; border: none; font-size: 14px; }
}

/* ===== Hero ===== */
.hero {
  padding: calc(var(--header-h) + 40px) 0 56px;
  background: var(--ink);
  background-image: radial-gradient(ellipse 55% 45% at 15% 40%, rgba(255, 138, 0, 0.07) 0%, transparent 65%);
}

.hero-inner {
  display: grid;
  grid-template-columns: 1fr;
  gap: 32px;
  align-items: center;
}

.hero-content { max-width: 560px; }

.hero-visual {
  width: 100%;
  max-width: 340px;
  margin: 0 auto;
  position: relative;
}

.hero-stack {
  position: relative;
  width: 100%;
  height: 420px;
}

.hero-stack figure {
  position: absolute;
  margin: 0;
  width: 52%;
}

.hero-stack img {
  width: 100%;
  aspect-ratio: 9/16;
  object-fit: cover;
  border-radius: 16px;
  border: 1px solid var(--line);
  box-shadow: 0 20px 50px rgba(0, 0, 0, 0.55);
}

.hero-stack figure:nth-child(1) { top: 0; right: 0; z-index: 4; transform: rotate(5deg); }
.hero-stack figure:nth-child(2) { top: 10%; right: 30%; z-index: 3; transform: rotate(-7deg); }
.hero-stack figure:nth-child(3) { top: 26%; right: 6%; z-index: 2; transform: rotate(8deg); opacity: 0.92; }
.hero-stack figure:nth-child(4) { top: 38%; right: 34%; z-index: 1; transform: rotate(-4deg); opacity: 0.82; }

.hero-stack figcaption { display: none; }

@media (min-width: 768px) {
  .hero-inner {
    grid-template-columns: 1fr 1fr;
    gap: 48px;
  }
  .hero-visual { max-width: 400px; margin: 0 0 0 auto; }
  .hero-stack { height: 480px; }
  .hero-stack figure { width: 54%; }
}

.hero-tag {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 6px 14px;
  background: var(--amber-dim);
  border: 1px solid var(--line-amber);
  border-radius: 999px;
  font-size: 12px;
  color: var(--amber-bright);
  letter-spacing: 0.06em;
  margin-bottom: 20px;
}

.hero-tag::before {
  content: "";
  width: 6px; height: 6px;
  background: var(--amber);
  border-radius: 50%;
  animation: pulse 2s infinite;
}

@keyframes pulse {
  0%, 100% { opacity: 1; }
  50% { opacity: 0.4; }
}

.hero h1 {
  font-family: var(--font-display);
  font-size: clamp(1.75rem, 5.5vw, 2.75rem);
  font-weight: 800;
  line-height: 1.25;
  margin-bottom: 18px;
  letter-spacing: -0.02em;
}

.hero h1 em {
  font-style: normal;
  background: linear-gradient(135deg, var(--amber) 0%, var(--gold) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.hero-lead {
  font-size: 15px;
  color: var(--text-dim);
  margin-bottom: 28px;
  max-width: 480px;
}

.hero-metrics {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 12px;
  margin-top: 32px;
}

.metric {
  padding: 14px 12px;
  background: rgba(255, 255, 255, 0.03);
  border: 1px solid var(--line);
  border-radius: var(--radius-sm);
  text-align: center;
}

.metric strong {
  display: block;
  font-size: 1.25rem;
  color: var(--amber);
  font-weight: 700;
}

.metric span { font-size: 11px; color: var(--text-faint); }

/* Showcase grid */
.showcase-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 14px;
  margin-top: 28px;
}

.showcase-item {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius-sm);
  overflow: hidden;
  transition: border-color 0.25s;
}

.showcase-item:hover { border-color: var(--line-amber); }

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

.showcase-item figcaption {
  padding: 10px 12px;
  font-size: 12px;
  color: var(--text-dim);
  line-height: 1.5;
}

@media (min-width: 640px) {
  .showcase-grid { grid-template-columns: repeat(3, 1fr); }
}

@media (min-width: 900px) {
  .showcase-grid { grid-template-columns: repeat(5, 1fr); }
}

/* Pure text SEO blocks */
.prose-section { padding: 48px 0; }
.prose-section-alt { background: var(--ink-soft); }

.prose-section h2 {
  font-family: var(--font-display);
  font-size: clamp(1.25rem, 3.5vw, 1.65rem);
  font-weight: 700;
  margin-bottom: 16px;
  line-height: 1.35;
}

.prose-section p {
  font-size: 14px;
  color: var(--text-dim);
  margin-bottom: 14px;
}

.text-columns {
  display: grid;
  grid-template-columns: 1fr;
  gap: 24px;
  margin-top: 20px;
}

.text-col h3 {
  font-size: 15px;
  font-weight: 700;
  margin-bottom: 10px;
  color: var(--text);
}

.text-col p { font-size: 14px; color: var(--text-dim); margin-bottom: 10px; }

@media (min-width: 768px) {
  .text-columns { grid-template-columns: repeat(2, 1fr); gap: 32px; }
}

.highlight-box {
  padding: 24px 20px;
  background: var(--surface);
  border-left: 3px solid var(--amber);
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
  margin: 24px 0;
}

.highlight-box p { margin-bottom: 0; }

/* ===== Download Zone & Ads ===== */
.download-zone {
  padding: 36px 0 48px;
  background: var(--ink-soft);
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
}

.download-zone-head {
  text-align: center;
  margin-bottom: 20px;
}

.download-zone-head h2 {
  font-size: 1.25rem;
  font-weight: 700;
  margin-bottom: 6px;
}

.download-zone-head p { font-size: 13px; color: var(--text-dim); }

#ads {
  display: flex;
  justify-content: center;
  align-items: flex-start;
  flex-wrap: wrap;
  gap: 8px;
  background: transparent;
  margin: 16px 0 8px;
}

#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 6px 20px rgba(0, 0, 0, 0.35);
  transition: transform 0.18s, box-shadow 0.18s;
  border: 1px solid var(--line);
}

#ads a { display: inline-block; border-radius: 16px; }

#ads img:hover {
  transform: translateY(-3px) scale(1.04);
  box-shadow: 0 12px 28px rgba(255, 138, 0, 0.2);
}

#ads .caption {
  height: 15px;
  font-size: 11px;
  color: var(--text-faint);
  text-align: center;
  max-width: 70px;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
  margin-top: 4px;
}

/* Sticky ads bar */
#ads-sticky-bar {
  position: fixed;
  left: 0; right: 0;
  z-index: 998;
  background: rgba(6, 6, 8, 0.96);
  backdrop-filter: blur(14px);
  border-top: 1px solid var(--line-amber);
  padding: 10px 12px;
  transform: translateY(110%);
  opacity: 0;
  pointer-events: none;
  transition: transform 0.35s, opacity 0.35s;
}

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

#ads-sticky-bar { bottom: 0; top: auto; }

@media (min-width: 768px) {
  #ads-sticky-bar {
    top: var(--header-h);
    bottom: auto;
    border-top: none;
    border-bottom: 1px solid var(--line-amber);
    padding: 8px 16px;
  }
  body.has-sticky-ads-pc { padding-top: 88px; }
  body.has-sticky-ads-pc { padding-bottom: 0; }
}

#ads-sticky-inner {
  display: flex;
  justify-content: center;
  flex-wrap: wrap;
  gap: 6px;
  max-width: var(--max);
  margin: 0 auto;
}

#ads-sticky-inner > div { width: calc(25% - 6px); max-width: 72px; }

@media (min-width: 768px) {
  #ads-sticky-inner > div { width: calc(12.5% - 8px); max-width: 72px; }
}

#ads-sticky-inner img {
  width: 100%;
  aspect-ratio: 1;
  object-fit: cover;
  border-radius: 14px;
  border: 1px solid var(--line);
}

#ads-sticky-inner .caption { display: none; }

/* ===== Sections ===== */
.section { padding: 56px 0; }
.section-alt { background: var(--ink-soft); }

.section-label {
  display: inline-block;
  font-size: 11px;
  font-weight: 600;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--amber);
  margin-bottom: 10px;
}

.section-title {
  font-family: var(--font-display);
  font-size: clamp(1.35rem, 4vw, 1.85rem);
  font-weight: 700;
  line-height: 1.35;
  margin-bottom: 14px;
}

.section-desc {
  color: var(--text-dim);
  font-size: 14px;
  max-width: 640px;
  margin-bottom: 32px;
}

/* Split block 3:7 ratio */
.split-block {
  display: grid;
  grid-template-columns: 1fr;
  gap: 24px;
  margin-bottom: 40px;
  align-items: center;
}

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

.split-media {
  position: relative;
  border-radius: var(--radius);
  overflow: hidden;
  border: 1px solid var(--line);
  box-shadow: 0 16px 48px rgba(0, 0, 0, 0.4);
}

.split-media img { width: 100%; aspect-ratio: 9/16; object-fit: cover; max-height: 480px; margin: 0 auto; }

.split-media::after {
  content: "";
  position: absolute;
  inset: 0;
  background: linear-gradient(180deg, transparent 60%, rgba(6, 6, 8, 0.5) 100%);
  pointer-events: none;
}

.split-body h3 {
  font-size: 1.15rem;
  font-weight: 700;
  margin-bottom: 12px;
  color: var(--text);
}

.split-body p {
  color: var(--text-dim);
  font-size: 14px;
  margin-bottom: 12px;
}

.split-body ul {
  list-style: none;
  margin: 16px 0;
}

.split-body li {
  position: relative;
  padding-left: 18px;
  margin-bottom: 8px;
  font-size: 14px;
  color: var(--text-dim);
}

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

@media (min-width: 768px) {
  .split-block {
    grid-template-columns: 3fr 7fr;
    gap: 36px;
  }
  .split-block.reverse { grid-template-columns: 7fr 3fr; }
  .split-block.reverse .split-media { order: 0; }
}

/* Bento grid */
.bento {
  display: grid;
  grid-template-columns: 1fr;
  gap: 14px;
}

.bento-card {
  padding: 24px 20px;
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  transition: border-color 0.25s;
}

.bento-card:hover { border-color: var(--line-amber); }

.bento-icon {
  width: 44px; height: 44px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--amber-dim);
  border-radius: 12px;
  font-size: 20px;
  margin-bottom: 14px;
}

.bento-card h3 { font-size: 15px; font-weight: 700; margin-bottom: 8px; }
.bento-card p { font-size: 13px; color: var(--text-dim); line-height: 1.7; }

@media (min-width: 640px) {
  .bento { grid-template-columns: repeat(2, 1fr); }
}

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

/* Steps */
.steps { counter-reset: step; }

.step-item {
  display: flex;
  gap: 18px;
  margin-bottom: 28px;
  padding-bottom: 28px;
  border-bottom: 1px solid var(--line);
}

.step-item:last-child { border-bottom: none; margin-bottom: 0; padding-bottom: 0; }

.step-num {
  flex-shrink: 0;
  width: 40px; height: 40px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: linear-gradient(135deg, var(--amber) 0%, #e07000 100%);
  color: var(--ink);
  font-weight: 800;
  font-size: 16px;
  border-radius: 12px;
}

.step-body h3 { font-size: 15px; font-weight: 700; margin-bottom: 8px; }
.step-body p { font-size: 14px; color: var(--text-dim); }

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

.faq-item {
  border: 1px solid var(--line);
  border-radius: var(--radius-sm);
  margin-bottom: 10px;
  overflow: hidden;
  background: var(--surface);
}

.faq-q {
  width: 100%;
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 16px 18px;
  background: none;
  border: none;
  color: var(--text);
  font-size: 14px;
  font-weight: 600;
  text-align: left;
  cursor: pointer;
  font-family: inherit;
}

.faq-q::after {
  content: "+";
  font-size: 18px;
  color: var(--amber);
  transition: transform 0.25s;
}

.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 18px 16px;
  font-size: 14px;
  color: var(--text-dim);
}

.faq-item.open .faq-a { max-height: 400px; }

/* CTA */
.cta-band {
  padding: 48px 0;
  text-align: center;
  background: linear-gradient(135deg, rgba(255, 138, 0, 0.08) 0%, rgba(255, 176, 32, 0.04) 100%);
  border-top: 1px solid var(--line-amber);
  border-bottom: 1px solid var(--line-amber);
}

.cta-band h2 { font-size: 1.35rem; margin-bottom: 10px; }
.cta-band p { color: var(--text-dim); font-size: 14px; margin-bottom: 20px; }

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 13px 28px;
  background: linear-gradient(135deg, var(--amber) 0%, #e07000 100%);
  color: var(--ink);
  font-weight: 700;
  font-size: 14px;
  border-radius: 999px;
  border: none;
  cursor: pointer;
  transition: transform 0.2s, box-shadow 0.2s;
  box-shadow: 0 8px 28px rgba(255, 138, 0, 0.3);
}

.btn:hover {
  transform: translateY(-2px);
  box-shadow: 0 12px 36px rgba(255, 138, 0, 0.4);
  color: var(--ink);
}

.btn-outline {
  background: transparent;
  color: var(--amber);
  border: 1px solid var(--line-amber);
  box-shadow: none;
}

.btn-outline:hover { background: var(--amber-dim); color: var(--amber-bright); }

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

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

.footer-brand p { font-size: 13px; color: var(--text-faint); margin-top: 10px; max-width: 280px; }

.footer-links h4 {
  font-size: 12px;
  letter-spacing: 0.1em;
  color: var(--text-dim);
  margin-bottom: 12px;
}

.footer-links a {
  display: block;
  font-size: 13px;
  color: var(--text-faint);
  padding: 4px 0;
}

.footer-links a:hover { color: var(--amber); }

.footer-bottom {
  padding-top: 20px;
  border-top: 1px solid var(--line);
  font-size: 12px;
  color: var(--text-faint);
  text-align: center;
}

@media (min-width: 640px) {
  .footer-grid { grid-template-columns: 2fr 1fr 1fr; }
}

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

.page-hero h1 { font-size: 1.5rem; font-weight: 700; margin-bottom: 8px; }
.page-hero p { font-size: 14px; color: var(--text-dim); }

.breadcrumb {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
  font-size: 12px;
  color: var(--text-faint);
  margin-bottom: 16px;
}

.breadcrumb a { color: var(--text-dim); }
.breadcrumb span { color: var(--text-faint); }

.page-content {
  padding: 40px 0 56px;
  max-width: 760px;
}

.page-content h2 {
  font-size: 1.15rem;
  font-weight: 700;
  margin: 28px 0 12px;
  color: var(--text);
}

.page-content h3 {
  font-size: 1rem;
  font-weight: 600;
  margin: 20px 0 10px;
}

.page-content p, .page-content li {
  font-size: 14px;
  color: var(--text-dim);
  margin-bottom: 12px;
}

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

/* Error pages */
.error-page {
  min-height: 80vh;
  display: flex;
  align-items: center;
  justify-content: center;
  text-align: center;
  padding: calc(var(--header-h) + 40px) 18px 60px;
}

.error-code {
  font-size: 5rem;
  font-weight: 800;
  background: linear-gradient(135deg, var(--amber) 0%, var(--gold) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  line-height: 1;
  margin-bottom: 12px;
}

.error-page h1 { font-size: 1.25rem; margin-bottom: 10px; }
.error-page p { color: var(--text-dim); font-size: 14px; margin-bottom: 24px; }

.prose-block {
  margin-bottom: 24px;
}

.prose-block p { margin-bottom: 14px; }

.link-grid {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-top: 16px;
}

.link-grid a {
  padding: 8px 16px;
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: 999px;
  font-size: 13px;
  color: var(--text-dim);
}

.link-grid a:hover { border-color: var(--line-amber); color: var(--amber); }