/* 91PO官方网站 — Midnight Ember 原创视觉体系 */
:root {
  --void: #07080d;
  --void-2: #0e1018;
  --void-3: #151822;
  --ember: #ff7a18;
  --ember-glow: #ff9a3c;
  --ember-dim: rgba(255, 122, 24, 0.14);
  --violet: #8b5cf6;
  --violet-dim: rgba(139, 92, 246, 0.12);
  --ice: #e8eaf2;
  --mist: #9aa0b8;
  --fog: #5c6278;
  --line: rgba(255, 255, 255, 0.06);
  --line-ember: rgba(255, 122, 24, 0.28);
  --header-h: 56px;
  --sticky-ads-h: 88px;
  --radius: 18px;
  --radius-sm: 10px;
  --max: 1100px;
  --font: "Noto Serif SC", "Source Han Serif SC", "Songti SC", serif;
  --font-display: "Lexend", "Noto Serif SC", 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(--void);
  color: var(--ice);
  line-height: 1.85;
  font-size: 15px;
  overflow-x: hidden;
}

body.has-sticky-ads { padding-bottom: calc(var(--sticky-ads-h) + 8px); }
body.has-sticky-ads-pc { padding-top: var(--sticky-ads-h); }

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

a { color: var(--ember-glow); text-decoration: none; transition: color 0.2s; }
a:hover { color: #ffc078; }

.container { width: 100%; max-width: var(--max); margin: 0 auto; padding: 0 16px; }

/* ===== Header ===== */
.site-header {
  position: fixed;
  top: 0; left: 0; right: 0;
  z-index: 1000;
  height: var(--header-h);
  background: rgba(7, 8, 13, 0.9);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border-bottom: 1px solid var(--line);
}

.site-header.scrolled { box-shadow: 0 8px 40px rgba(0, 0, 0, 0.5); }

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: var(--header-h);
  max-width: var(--max);
  margin: 0 auto;
  padding: 0 16px;
}

.brand {
  display: flex;
  align-items: center;
  gap: 10px;
  color: var(--ice);
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 15px;
  letter-spacing: 0.06em;
}

.brand img { width: 36px; height: 36px; border-radius: 10px; }

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

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

.main-nav {
  display: none;
  position: fixed;
  top: var(--header-h);
  left: 0; right: 0;
  background: rgba(7, 8, 13, 0.97);
  border-bottom: 1px solid var(--line);
  padding: 12px 16px 20px;
  flex-direction: column;
  gap: 4px;
}

.main-nav.open { display: flex; }

.main-nav a {
  color: var(--mist);
  font-size: 15px;
  padding: 10px 12px;
  border-radius: var(--radius-sm);
  transition: background 0.2s, color 0.2s;
}

.main-nav a:hover,
.main-nav a.active { color: var(--ice); background: var(--ember-dim); }

/* ===== Sticky Ads Bar ===== */
#ads-sticky-bar {
  position: fixed;
  left: 0; right: 0;
  z-index: 999;
  background: rgba(14, 16, 24, 0.96);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border-bottom: 1px solid var(--line);
  transform: translateY(-110%);
  opacity: 0;
  transition: transform 0.35s ease, opacity 0.35s ease;
  pointer-events: none;
}

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

body.has-sticky-ads-pc #ads-sticky-bar { top: var(--header-h); }
body.has-sticky-ads:not(.has-sticky-ads-pc) #ads-sticky-bar {
  top: auto;
  bottom: 0;
  border-bottom: none;
  border-top: 1px solid var(--line);
  box-shadow: 0 -6px 32px rgba(0, 0, 0, 0.45);
}

#ads-sticky-inner,
#ads {
  display: flex;
  justify-content: center;
  align-items: flex-start;
  flex-wrap: wrap;
  gap: 6px 4px;
  padding: 8px 10px;
}

#ads-sticky-inner > div,
#ads > div {
  display: flex;
  flex-direction: column;
  align-items: center;
  width: calc(25% - 4px);
  box-sizing: border-box;
}

#ads-sticky-inner img,
#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 ease;
  border: 1px solid var(--line);
}

#ads-sticky-inner a:hover img,
#ads a:hover img { transform: translateY(-3px) scale(1.03); }

#ads-sticky-inner .caption,
#ads .caption {
  height: 14px;
  font-size: 10px;
  color: var(--fog);
  text-align: center;
  max-width: 72px;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
  margin-top: 3px;
}

/* ===== Download Band ===== */
.download-band {
  padding: calc(var(--header-h) + 16px) 0 20px;
  background: linear-gradient(180deg, var(--void-2) 0%, var(--void) 100%);
  border-bottom: 1px solid var(--line);
}

.band-label {
  text-align: center;
  font-size: 12px;
  color: var(--fog);
  letter-spacing: 0.12em;
  text-transform: uppercase;
  margin-bottom: 10px;
}

/* ===== Hero ===== */
.hero-panel {
  position: relative;
  padding: 36px 0 56px;
  overflow: visible;
}

.hero-panel::before {
  content: "";
  position: absolute;
  inset: 0;
  background:
    radial-gradient(ellipse 60% 50% at 20% 40%, var(--ember-dim) 0%, transparent 70%),
    radial-gradient(ellipse 50% 40% at 80% 60%, var(--violet-dim) 0%, transparent 70%);
  pointer-events: none;
}

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

.hero-cascade {
  position: relative;
  width: 100%;
  max-width: 300px;
  height: 360px;
  margin: 0 auto;
  overflow: visible;
}

.hero-cascade img {
  position: absolute;
  width: 112px;
  max-width: none;
  height: auto;
  border-radius: 20px;
  box-shadow: 0 20px 60px rgba(0, 0, 0, 0.55);
  border: 2px solid rgba(255, 255, 255, 0.08);
  object-fit: cover;
}

.hero-cascade .hc-1 { left: 0; top: 28px; transform: rotate(-7deg); z-index: 1; }
.hero-cascade .hc-2 { left: 58px; top: 0; transform: rotate(5deg); z-index: 3; }
.hero-cascade .hc-3 { left: 118px; top: 22px; transform: rotate(-2deg); z-index: 2; }
.hero-cascade .hc-4 { left: 78px; top: 108px; transform: rotate(7deg); z-index: 4; }

.hero-text { text-align: center; }

.hero-eyebrow {
  display: inline-block;
  font-size: 11px;
  letter-spacing: 0.14em;
  color: var(--ember-glow);
  border: 1px solid var(--line-ember);
  padding: 5px 14px;
  border-radius: 100px;
  margin-bottom: 18px;
  background: var(--ember-dim);
}

.hero-text h1 {
  font-family: var(--font-display);
  font-size: clamp(26px, 6vw, 40px);
  font-weight: 800;
  line-height: 1.25;
  color: var(--ice);
  margin-bottom: 16px;
}

.hero-text h1 em {
  display: block;
  font-style: normal;
  font-size: 0.55em;
  font-weight: 500;
  color: var(--mist);
  margin-top: 10px;
  letter-spacing: 0.02em;
}

.hero-lead {
  color: var(--mist);
  font-size: 15px;
  max-width: 520px;
  margin: 0 auto 22px;
}

.hero-chips {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 8px;
  margin-bottom: 24px;
}

.hero-chips span {
  font-size: 12px;
  padding: 6px 14px;
  border-radius: 100px;
  background: var(--void-3);
  border: 1px solid var(--line);
  color: var(--mist);
}

.hero-chips strong { color: var(--ember-glow); font-weight: 600; }

.hero-scroll {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-size: 13px;
  color: var(--fog);
  padding: 10px 18px;
  border-radius: 100px;
  border: 1px solid var(--line);
  transition: border-color 0.2s, color 0.2s;
}

.hero-scroll:hover { color: var(--ice); border-color: var(--line-ember); }
.hero-scroll svg { width: 16px; height: 16px; }

/* ===== Sections ===== */
.section { padding: 52px 0; }
.section.alt { background: var(--void-2); }

.section-head { margin-bottom: 32px; }

.section-tag {
  font-size: 11px;
  letter-spacing: 0.12em;
  color: var(--violet);
  text-transform: uppercase;
  margin-bottom: 8px;
}

.section-head h2 {
  font-family: var(--font-display);
  font-size: clamp(22px, 4.5vw, 30px);
  font-weight: 700;
  line-height: 1.35;
  color: var(--ice);
}

.section-head p {
  color: var(--mist);
  margin-top: 10px;
  max-width: 640px;
}

/* ===== Split 3:7 ===== */
.split-37 {
  display: grid;
  grid-template-columns: 1fr;
  gap: 28px;
  align-items: start;
}

.split-37 .split-visual {
  position: relative;
}

.split-37 .split-visual img {
  border-radius: var(--radius);
  box-shadow: 0 16px 48px rgba(0, 0, 0, 0.4);
  border: 1px solid var(--line);
}

.split-37 .split-visual figcaption {
  font-size: 12px;
  color: var(--fog);
  margin-top: 10px;
  text-align: center;
}

.split-37 .split-body h3 {
  font-family: var(--font-display);
  font-size: 20px;
  color: var(--ice);
  margin-bottom: 12px;
}

.split-37 .split-body p {
  color: var(--mist);
  margin-bottom: 14px;
}

.split-37 .split-body ul {
  list-style: none;
  margin: 16px 0;
}

.split-37 .split-body li {
  position: relative;
  padding-left: 20px;
  margin-bottom: 10px;
  color: var(--mist);
  font-size: 14px;
}

.split-37 .split-body li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 10px;
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--ember);
}

/* ===== Feature Grid ===== */
.feat-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 14px;
}

.feat-card {
  background: var(--void-3);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 22px 20px;
  transition: border-color 0.25s;
}

.feat-card:hover { border-color: var(--line-ember); }

.feat-num {
  font-family: var(--font-display);
  font-size: 28px;
  font-weight: 800;
  color: var(--ember);
  opacity: 0.5;
  line-height: 1;
  margin-bottom: 10px;
}

.feat-card h3 {
  font-size: 16px;
  color: var(--ice);
  margin-bottom: 8px;
}

.feat-card p { font-size: 14px; color: var(--mist); line-height: 1.75; }

/* ===== Stats Row ===== */
.stats-row {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 12px;
  margin: 28px 0;
}

.stat-box {
  text-align: center;
  padding: 20px 12px;
  background: var(--void-3);
  border-radius: var(--radius);
  border: 1px solid var(--line);
}

.stat-box strong {
  display: block;
  font-family: var(--font-display);
  font-size: 26px;
  color: var(--ember-glow);
  line-height: 1.2;
}

.stat-box span { font-size: 12px; color: var(--fog); }

/* ===== FAQ ===== */
.faq-list { display: flex; flex-direction: column; gap: 10px; }

.faq-item {
  background: var(--void-3);
  border: 1px solid var(--line);
  border-radius: var(--radius-sm);
  overflow: hidden;
}

.faq-btn {
  width: 100%;
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 12px;
  padding: 16px 18px;
  background: none;
  border: none;
  color: var(--ice);
  font-size: 15px;
  text-align: left;
  cursor: pointer;
  font-family: var(--font);
}

.faq-btn svg {
  flex-shrink: 0;
  width: 18px;
  height: 18px;
  color: var(--fog);
  transition: transform 0.3s;
}

.faq-item.open .faq-btn svg { transform: rotate(180deg); }

.faq-body {
  display: none;
  padding: 0 18px 16px;
  color: var(--mist);
  font-size: 14px;
}

.faq-item.open .faq-body { display: block; }

/* ===== CTA Band ===== */
.cta-band {
  text-align: center;
  padding: 48px 20px;
  background: linear-gradient(135deg, var(--void-3) 0%, rgba(139, 92, 246, 0.08) 50%, var(--void-2) 100%);
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
}

.cta-band h2 {
  font-family: var(--font-display);
  font-size: 22px;
  margin-bottom: 10px;
}

.cta-band p { color: var(--mist); margin-bottom: 20px; font-size: 14px; }

.btn-ember {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 13px 28px;
  background: linear-gradient(135deg, var(--ember) 0%, #ff5722 100%);
  color: #fff;
  font-weight: 600;
  font-size: 14px;
  border-radius: 100px;
  border: none;
  cursor: pointer;
  transition: transform 0.2s, box-shadow 0.2s;
  box-shadow: 0 6px 24px rgba(255, 122, 24, 0.3);
}

.btn-ember:hover {
  color: #fff;
  transform: translateY(-2px);
  box-shadow: 0 10px 32px rgba(255, 122, 24, 0.4);
}

/* ===== Prose Block ===== */
.prose-block { max-width: 760px; }
.prose-block h3 {
  font-family: var(--font-display);
  font-size: 18px;
  color: var(--ice);
  margin: 28px 0 12px;
}
.prose-block p { color: var(--mist); margin-bottom: 14px; font-size: 14px; }
.prose-block ol { padding-left: 20px; color: var(--mist); font-size: 14px; }
.prose-block ol li { margin-bottom: 8px; }

/* ===== Breadcrumb ===== */
.breadcrumb {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 13px;
  color: var(--fog);
  padding: calc(var(--header-h) + 20px) 0 16px;
}

.breadcrumb a { color: var(--mist); }
.breadcrumb a:hover { color: var(--ember-glow); }
.breadcrumb span:last-child { color: var(--ice); }

/* ===== Page Banner ===== */
.page-banner {
  padding: 24px 0 40px;
  border-bottom: 1px solid var(--line);
  margin-bottom: 32px;
}

.page-banner h1 {
  font-family: var(--font-display);
  font-size: clamp(24px, 5vw, 34px);
  margin-bottom: 12px;
}

.page-banner p { color: var(--mist); max-width: 600px; }

/* ===== Legal Content ===== */
.legal-content {
  padding-bottom: 60px;
  max-width: 760px;
}

.legal-content h2 {
  font-family: var(--font-display);
  font-size: 18px;
  color: var(--ice);
  margin: 32px 0 12px;
}

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

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

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

/* ===== Error Pages ===== */
.error-page {
  min-height: 70vh;
  display: flex;
  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: 80px;
  font-weight: 800;
  color: var(--ember);
  opacity: 0.6;
  line-height: 1;
}

.error-page h1 { font-size: 22px; margin: 16px 0 10px; }
.error-page p { color: var(--mist); margin-bottom: 24px; font-size: 14px; }

/* ===== Footer ===== */
.site-footer {
  background: var(--void-2);
  border-top: 1px solid var(--line);
  padding: 40px 0 28px;
}

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

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

.footer-links h4 {
  font-size: 13px;
  color: var(--ice);
  margin-bottom: 12px;
  letter-spacing: 0.06em;
}

.footer-links ul { list-style: none; }

.footer-links li { margin-bottom: 8px; }

.footer-links a { font-size: 13px; color: var(--fog); }
.footer-links a:hover { color: var(--ember-glow); }

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

/* ===== Gallery Strip ===== */
.gallery-strip {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 12px;
  margin-top: 24px;
}

.gallery-card {
  background: var(--void-3);
  border: 1px solid var(--line);
  border-radius: var(--radius-sm);
  overflow: hidden;
  transition: border-color 0.25s;
}

.gallery-card:hover { border-color: var(--line-ember); }

.gallery-card img {
  width: 100%;
  aspect-ratio: 9/16;
  object-fit: cover;
  object-position: top;
}

.gallery-card figcaption {
  padding: 10px 12px;
  font-size: 12px;
  color: var(--mist);
  line-height: 1.5;
}

/* ===== SEO Article ===== */
.seo-article {
  max-width: 800px;
}

.seo-article h3 {
  font-family: var(--font-display);
  font-size: 18px;
  color: var(--ice);
  margin: 28px 0 12px;
}

.seo-article h3:first-child { margin-top: 0; }

.seo-article p {
  color: var(--mist);
  font-size: 14px;
  margin-bottom: 14px;
}

.seo-article ul,
.seo-article ol {
  padding-left: 22px;
  margin-bottom: 16px;
  color: var(--mist);
  font-size: 14px;
}

.seo-article li { margin-bottom: 8px; }

.compare-list {
  display: grid;
  gap: 12px;
  margin: 20px 0;
}

.compare-item {
  display: grid;
  grid-template-columns: 1fr;
  gap: 4px;
  padding: 16px 18px;
  background: var(--void-3);
  border: 1px solid var(--line);
  border-radius: var(--radius-sm);
}

.compare-item strong {
  color: var(--ember-glow);
  font-size: 14px;
}

.compare-item span {
  color: var(--mist);
  font-size: 13px;
}

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

  .main-nav {
    display: flex;
    position: static;
    flex-direction: row;
    background: none;
    border: none;
    padding: 0;
    gap: 4px;
  }

  .main-nav a { font-size: 13px; padding: 6px 12px; }

  .hero-grid {
    grid-template-columns: 42% 58%;
    gap: 40px;
  }

  .hero-text { text-align: left; }
  .hero-lead { margin-left: 0; }
  .hero-chips { justify-content: flex-start; }

  .hero-cascade {
    height: 420px;
    max-width: 100%;
    margin: 0;
  }

  .hero-cascade img { width: 168px; }

  .hero-cascade .hc-1 { left: 0; top: 20px; transform: rotate(-8deg); }
  .hero-cascade .hc-2 { left: 72px; top: 0; transform: rotate(4deg); }
  .hero-cascade .hc-3 { left: 148px; top: 36px; transform: rotate(-3deg); }
  .hero-cascade .hc-4 { left: 100px; top: 120px; transform: rotate(6deg); }

  .split-37 {
    grid-template-columns: 30% 70%;
    gap: 36px;
  }

  .split-37.reverse { direction: rtl; }
  .split-37.reverse > * { direction: ltr; }

  .feat-grid { grid-template-columns: repeat(3, 1fr); }

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

  .footer-grid { grid-template-columns: 1.4fr 1fr 1fr; }

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

  .compare-item { grid-template-columns: 140px 1fr; align-items: center; }

  #ads-sticky-inner > div,
  #ads > div { width: calc(12.5% - 4px); }

  #ads-sticky-inner img,
  #ads img { width: 65px; height: 65px; }
}

@media (min-width: 1024px) {
  .hero-cascade img { width: 185px; }
  .hero-cascade .hc-3 { left: 168px; }
  .hero-cascade .hc-4 { left: 118px; }
}