/* 91PO官网 — 91-s.forum 品牌站 */
:root {
  --ink: #0c0c10;
  --surface: #14141c;
  --surface-2: #1c1c28;
  --amber: #ff9900;
  --amber-soft: #ffb84d;
  --amber-dim: rgba(255, 153, 0, 0.14);
  --coral: #ff6b35;
  --gold: #e8b84a;
  --text: #ececf2;
  --text-dim: #9a9ab0;
  --text-faint: #636378;
  --line: rgba(255, 255, 255, 0.07);
  --radius: 16px;
  --radius-sm: 10px;
  --header-h: 58px;
  --sticky-ads-h: 0px;
  --serif: "Noto Serif SC", "Songti SC", "SimSun", serif;
  --sans: "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  --ease: 0.28s cubic-bezier(0.33, 1, 0.68, 1);
  --max: 1080px;
}

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

html {
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
  scroll-padding-top: calc(var(--header-h) + var(--sticky-ads-h) + 12px);
}

body {
  font-family: var(--sans);
  background: var(--ink);
  color: var(--text);
  line-height: 1.82;
  font-size: 15px;
  overflow-x: hidden;
}

body.ads-pinned { --sticky-ads-h: 88px; }

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

a {
  color: var(--amber-soft);
  text-decoration: none;
  transition: color var(--ease);
}
a:hover { color: var(--amber); }

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

/* ── Header ── */
.site-header {
  position: fixed;
  inset: 0 0 auto 0;
  z-index: 900;
  height: var(--header-h);
  background: rgba(12, 12, 16, 0.92);
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);
  border-bottom: 1px solid var(--line);
}

.header-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: var(--header-h);
  gap: 10px;
}

.brand {
  display: flex;
  align-items: center;
  gap: 10px;
  color: var(--text);
  font-weight: 700;
  font-size: 17px;
  letter-spacing: 0.02em;
}
.brand img { border-radius: 10px; width: 36px; height: 36px; }
.brand em { color: var(--amber); font-style: normal; }

.nav-main { display: none; gap: 6px; }
.nav-main a {
  padding: 7px 14px;
  border-radius: 999px;
  color: var(--text-dim);
  font-size: 14px;
}
.nav-main a:hover,
.nav-main a.active { color: var(--text); background: var(--amber-dim); }

.btn-cta {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 9px 18px;
  border-radius: 999px;
  background: var(--amber);
  color: #111;
  font-weight: 700;
  font-size: 13px;
  border: none;
  cursor: pointer;
  transition: transform var(--ease), box-shadow var(--ease);
  white-space: nowrap;
}
.btn-cta:hover {
  color: #111;
  transform: translateY(-1px);
  box-shadow: 0 8px 24px rgba(255, 153, 0, 0.35);
}

.btn-cta-nav { display: none; }
@media (min-width: 768px) {
  .btn-cta-nav { display: inline-flex; }
}

.menu-btn {
  display: flex;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 6px;
}
.menu-btn span {
  display: block;
  width: 22px;
  height: 2px;
  background: var(--text);
  border-radius: 2px;
  transition: var(--ease);
}
.menu-btn.open span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
.menu-btn.open span:nth-child(2) { opacity: 0; }
.menu-btn.open span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

.nav-drawer {
  display: none;
  position: fixed;
  top: var(--header-h);
  left: 0; right: 0;
  background: var(--surface);
  border-bottom: 1px solid var(--line);
  padding: 12px 16px 18px;
  z-index: 890;
}
.nav-drawer.show { display: block; }
.nav-drawer a {
  display: block;
  padding: 12px 0;
  color: var(--text-dim);
  border-bottom: 1px solid var(--line);
  font-size: 15px;
}
.nav-drawer a:last-child { border-bottom: none; }

/* ── Sticky Ads ── */
.sticky-ads-bar {
  position: fixed;
  top: var(--header-h);
  left: 0; right: 0;
  z-index: 880;
  background: rgba(20, 20, 28, 0.96);
  border-bottom: 1px solid var(--line);
  padding: 8px 0;
  transform: translateY(-110%);
  opacity: 0;
  pointer-events: none;
  transition: transform var(--ease), opacity var(--ease);
}
.sticky-ads-bar.visible {
  transform: translateY(0);
  opacity: 1;
  pointer-events: auto;
}

.ads-wrap {
  display: flex;
  justify-content: center;
  align-items: flex-start;
  flex-wrap: wrap;
  gap: 8px 12px;
  background: transparent;
}
.ads-wrap > div {
  display: flex;
  flex-direction: column;
  align-items: center;
  width: 70px;
}
.ads-wrap img {
  width: 58px;
  height: 58px;
  object-fit: cover;
  border-radius: 14px;
  box-shadow: 0 4px 14px rgba(0, 0, 0, 0.35);
  transition: transform var(--ease);
}
.ads-wrap a:hover img { transform: scale(1.05); }
.ads-wrap .caption {
  margin-top: 4px;
  font-size: 10px;
  color: var(--text-faint);
  text-align: center;
  max-width: 72px;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.ads-block {
  padding: 14px 0 6px;
  margin-top: var(--header-h);
}

/* ── Hero ── */
.hero {
  position: relative;
  padding: 36px 0 48px;
  overflow: hidden;
}
.hero::before {
  content: "";
  position: absolute;
  top: -40%;
  right: -20%;
  width: 70%;
  height: 140%;
  background: radial-gradient(ellipse, rgba(255, 153, 0, 0.12) 0%, transparent 65%);
  pointer-events: none;
}
.hero::after {
  content: "";
  position: absolute;
  bottom: 0; left: 0; right: 0;
  height: 1px;
  background: linear-gradient(90deg, transparent, var(--amber), transparent);
  opacity: 0.4;
}

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

.hero-tag {
  display: inline-block;
  padding: 5px 14px;
  border: 1px solid rgba(255, 153, 0, 0.35);
  border-radius: 999px;
  font-size: 12px;
  color: var(--amber-soft);
  letter-spacing: 0.06em;
  margin-bottom: 16px;
}

.hero h1 {
  font-family: var(--serif);
  font-size: clamp(26px, 6vw, 40px);
  font-weight: 700;
  line-height: 1.28;
  margin-bottom: 16px;
}
.hero h1 .accent { color: var(--amber); }

.hero-lead {
  color: var(--text-dim);
  font-size: 15px;
  margin-bottom: 22px;
  max-width: 540px;
}

.hero-chips {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-bottom: 24px;
}
.hero-chips span {
  padding: 6px 12px;
  background: var(--surface);
  border-radius: var(--radius-sm);
  font-size: 12px;
  color: var(--text-dim);
  border: 1px solid var(--line);
}

.hero-actions { display: flex; flex-wrap: wrap; gap: 12px; }

.btn-outline {
  display: inline-flex;
  align-items: center;
  padding: 10px 20px;
  border: 1px solid var(--line);
  border-radius: 999px;
  color: var(--text);
  font-size: 14px;
  transition: border-color var(--ease), background var(--ease);
}
.btn-outline:hover {
  border-color: var(--amber);
  background: var(--amber-dim);
  color: var(--text);
}

.hero-shot {
  position: relative;
  max-width: 300px;
  margin: 0 auto;
}
.hero-shot::before {
  content: "";
  position: absolute;
  inset: -8px;
  border-radius: 28px;
  border: 2px solid rgba(255, 153, 0, 0.25);
  pointer-events: none;
}
.hero-shot img {
  border-radius: 22px;
  box-shadow: 0 24px 60px rgba(0, 0, 0, 0.55);
}

/* ── Marquee ── */
.marquee {
  background: var(--surface);
  border-block: 1px solid var(--line);
  padding: 10px 0;
  overflow: hidden;
}
.marquee-track {
  display: flex;
  gap: 40px;
  animation: scroll-x 28s linear infinite;
  white-space: nowrap;
}
.marquee-track span {
  font-size: 13px;
  color: var(--text-faint);
  letter-spacing: 0.04em;
}
@keyframes scroll-x {
  0% { transform: translateX(0); }
  100% { transform: translateX(-50%); }
}

/* ── Sections ── */
.section { padding: 52px 0; }
.section-alt { background: var(--surface); }

.eyebrow {
  display: block;
  font-size: 12px;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--amber);
  margin-bottom: 10px;
}

.section h2 {
  font-family: var(--serif);
  font-size: clamp(22px, 4.5vw, 30px);
  font-weight: 700;
  margin-bottom: 14px;
  line-height: 1.35;
}

.section-intro {
  color: var(--text-dim);
  margin-bottom: 32px;
  max-width: 680px;
}

/* ── Bento Grid ── */
.bento {
  display: grid;
  gap: 14px;
  grid-template-columns: 1fr;
}
.bento-card {
  background: var(--surface-2);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 22px 20px;
  position: relative;
  overflow: hidden;
}
.bento-card::after {
  content: "";
  position: absolute;
  top: 0; left: 20px; right: 20px;
  height: 3px;
  background: linear-gradient(90deg, var(--amber), var(--coral));
  border-radius: 0 0 4px 4px;
}
.bento-icon {
  font-size: 26px;
  margin-bottom: 10px;
}
.bento-card h3 {
  font-size: 16px;
  font-weight: 700;
  margin-bottom: 8px;
}
.bento-card p {
  font-size: 14px;
  color: var(--text-dim);
  line-height: 1.7;
}

/* ── Feature Row (3:7 layout) ── */
.feature-row {
  display: grid;
  gap: 28px;
  align-items: center;
  margin-bottom: 48px;
}
.feature-row:last-child { margin-bottom: 0; }

.feature-media {
  position: relative;
}
.feature-media img {
  border-radius: var(--radius);
  border: 1px solid var(--line);
  box-shadow: 0 16px 40px rgba(0, 0, 0, 0.4);
}
.feature-media .label {
  position: absolute;
  bottom: 12px;
  left: 12px;
  padding: 4px 10px;
  background: rgba(12, 12, 16, 0.85);
  border-radius: 6px;
  font-size: 11px;
  color: var(--amber-soft);
}

.feature-copy h3 {
  font-family: var(--serif);
  font-size: 20px;
  margin-bottom: 12px;
}
.feature-copy p {
  color: var(--text-dim);
  font-size: 14px;
  margin-bottom: 12px;
}
.feature-copy ul {
  list-style: none;
  margin-top: 14px;
}
.feature-copy li {
  position: relative;
  padding-left: 18px;
  font-size: 14px;
  color: var(--text-dim);
  margin-bottom: 8px;
}
.feature-copy li::before {
  content: "▸";
  position: absolute;
  left: 0;
  color: var(--amber);
  font-size: 11px;
  top: 2px;
}

/* ── Metrics ── */
.metrics {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 12px;
}
.metric {
  background: var(--surface-2);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 20px 16px;
  text-align: center;
}
.metric strong {
  display: block;
  font-family: var(--serif);
  font-size: 26px;
  color: var(--amber);
  margin-bottom: 4px;
}
.metric span { font-size: 12px; color: var(--text-faint); }

/* ── Timeline Guide ── */
.timeline { position: relative; padding-left: 28px; }
.timeline::before {
  content: "";
  position: absolute;
  left: 8px;
  top: 8px;
  bottom: 8px;
  width: 2px;
  background: linear-gradient(180deg, var(--amber), transparent);
}
.timeline-item {
  position: relative;
  margin-bottom: 28px;
}
.timeline-item::before {
  content: "";
  position: absolute;
  left: -24px;
  top: 6px;
  width: 10px;
  height: 10px;
  border-radius: 50%;
  background: var(--amber);
  box-shadow: 0 0 0 4px var(--amber-dim);
}
.timeline-item h3 {
  font-size: 16px;
  margin-bottom: 8px;
}
.timeline-item p {
  font-size: 14px;
  color: var(--text-dim);
}

/* ── FAQ ── */
.faq-list { display: grid; gap: 12px; }
.faq-item {
  background: var(--surface-2);
  border: 1px solid var(--line);
  border-radius: var(--radius-sm);
  padding: 18px 20px;
}
.faq-item h3 {
  font-size: 15px;
  margin-bottom: 8px;
  color: var(--text);
}
.faq-item p {
  font-size: 14px;
  color: var(--text-dim);
}

/* ── Prose (subpages) ── */
.prose h2 {
  font-family: var(--serif);
  font-size: 22px;
  margin: 32px 0 14px;
}
.prose h3 {
  font-size: 17px;
  margin: 24px 0 10px;
}
.prose p, .prose li {
  color: var(--text-dim);
  font-size: 14px;
  margin-bottom: 12px;
}
.prose ul, .prose ol {
  padding-left: 20px;
  margin-bottom: 16px;
}
.prose li { margin-bottom: 6px; }

/* ── Breadcrumb ── */
.breadcrumb {
  padding: calc(var(--header-h) + 20px) 0 0;
  font-size: 13px;
  color: var(--text-faint);
}
.breadcrumb a { color: var(--text-dim); }
.breadcrumb span { margin: 0 6px; }

/* ── Page Hero (sub) ── */
.page-hero {
  padding: 24px 0 36px;
  border-bottom: 1px solid var(--line);
  margin-bottom: 32px;
}
.page-hero h1 {
  font-family: var(--serif);
  font-size: clamp(24px, 5vw, 32px);
}

/* ── CTA Band ── */
.cta-band {
  background: linear-gradient(135deg, rgba(255, 153, 0, 0.15), rgba(255, 107, 53, 0.08));
  border: 1px solid rgba(255, 153, 0, 0.2);
  border-radius: var(--radius);
  padding: 36px 24px;
  text-align: center;
  margin: 48px 0 0;
}
.cta-band h2 {
  font-family: var(--serif);
  font-size: 22px;
  margin-bottom: 10px;
}
.cta-band p {
  color: var(--text-dim);
  font-size: 14px;
  margin-bottom: 20px;
}

/* ── Footer ── */
.site-footer {
  background: var(--surface);
  border-top: 1px solid var(--line);
  padding: 40px 0 28px;
  margin-top: 60px;
}
.footer-grid {
  display: grid;
  gap: 28px;
  margin-bottom: 28px;
}
.footer-brand p {
  font-size: 13px;
  color: var(--text-faint);
  margin-top: 10px;
  max-width: 280px;
}
.footer-links h4 {
  font-size: 13px;
  color: var(--text);
  margin-bottom: 12px;
  letter-spacing: 0.04em;
}
.footer-links a {
  display: block;
  font-size: 13px;
  color: var(--text-faint);
  padding: 4px 0;
}
.footer-links a:hover { color: var(--amber-soft); }
.footer-bottom {
  padding-top: 20px;
  border-top: 1px solid var(--line);
  font-size: 12px;
  color: var(--text-faint);
  text-align: center;
}
.footer-partners {
  display: flex;
  flex-wrap: wrap;
  gap: 16px;
  margin-top: 12px;
  justify-content: center;
}
.footer-partners a { font-size: 12px; }

/* ── Error Pages ── */
.error-page {
  min-height: 60vh;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  text-align: center;
  padding: 40px 16px;
}
.error-code {
  font-family: var(--serif);
  font-size: 72px;
  color: var(--amber);
  line-height: 1;
  margin-bottom: 12px;
}
.error-page h1 { font-size: 22px; margin-bottom: 10px; }
.error-page p { color: var(--text-dim); font-size: 14px; margin-bottom: 24px; }

/* ── Channel Grid ── */
.channel-grid {
  display: grid;
  gap: 14px;
  grid-template-columns: 1fr;
}
.channel-card {
  background: var(--surface-2);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 22px 20px;
  border-left: 3px solid var(--amber);
}
.channel-card h3 {
  font-family: var(--serif);
  font-size: 17px;
  margin-bottom: 10px;
  color: var(--amber-soft);
}
.channel-card p {
  font-size: 14px;
  color: var(--text-dim);
  line-height: 1.78;
}

/* ── Gallery ── */
.gallery-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 14px;
}
.gallery-item {
  background: var(--surface-2);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  overflow: hidden;
}
.gallery-item img {
  width: 100%;
  aspect-ratio: 9/16;
  object-fit: cover;
  object-position: top;
}
.gallery-item figcaption {
  padding: 10px 12px;
  font-size: 12px;
  color: var(--text-dim);
  text-align: center;
  border-top: 1px solid var(--line);
}

/* ── Desktop ── */
@media (min-width: 768px) {
  .channel-grid { grid-template-columns: repeat(2, 1fr); }
  .gallery-grid { grid-template-columns: repeat(3, 1fr); }
  .nav-main { display: flex; }
  .menu-btn { display: none; }
  .nav-drawer { display: none !important; }

  .hero-inner {
    grid-template-columns: 1fr 280px;
    gap: 48px;
  }
  .hero-shot { margin: 0; }

  .bento {
    grid-template-columns: repeat(3, 1fr);
  }
  .bento-card.wide { grid-column: span 2; }

  .feature-row {
    grid-template-columns: 3fr 7fr;
    gap: 40px;
  }
  .feature-row.reverse { direction: rtl; }
  .feature-row.reverse > * { direction: ltr; }

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

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

@media (min-width: 1024px) {
  .feature-row { gap: 56px; }
}