/* ============================================================
   AcFun 流鼻血版官网样式
   配色取自 Logo：主橙 #FF9200 / 亮黄 #FFC53D / 深橙 #E8640C
   ============================================================ */

:root {
  --ac-orange: #ff9200;
  --ac-orange-deep: #e8640c;
  --ac-orange-dark: #c2530a;
  --ac-yellow: #ffc53d;
  --ac-ink: #2b2118;
  --ac-ink-soft: #6b5d4f;
  --ac-bg: #fff7ec;
  --ac-card: #ffffff;
  --radius-lg: 22px;
  --radius-md: 16px;
  --shadow-soft: 0 10px 30px rgba(232, 100, 12, .12);
  --shadow-pop: 0 20px 50px rgba(232, 100, 12, .22);
  --header-h: 68px;
}

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

html {
  scroll-behavior: smooth;
  scroll-padding-top: calc(var(--header-h) + 12px);
}

body {
  font-family: "PingFang SC", "Microsoft YaHei", "Helvetica Neue", Arial, sans-serif;
  color: var(--ac-ink);
  background: var(--ac-bg);
  line-height: 1.7;
  overflow-x: hidden;
}

img { display: block; max-width: 100%; }
a { text-decoration: none; color: inherit; }
ul { list-style: none; }

.container {
  width: min(1160px, 92%);
  margin: 0 auto;
}
.container-narrow { width: min(860px, 92%); }

/* ---------------- 顶部导航 ---------------- */
.site-header {
  position: fixed;
  inset: 0 0 auto 0;
  z-index: 100;
  height: var(--header-h);
  transition: background .3s ease, box-shadow .3s ease;
}
.site-header.is-scrolled {
  background: rgba(255, 247, 236, .92);
  backdrop-filter: blur(12px);
  box-shadow: 0 4px 20px rgba(232, 100, 12, .12);
}
.nav-wrap {
  height: var(--header-h);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
}
.brand {
  display: flex;
  align-items: center;
  gap: 10px;
  flex-shrink: 0;
}
.brand-logo {
  width: 42px;
  height: 42px;
  border-radius: 12px;
  object-fit: cover;
  background: linear-gradient(135deg, var(--ac-yellow), var(--ac-orange));
  box-shadow: 0 4px 12px rgba(232, 100, 12, .35);
}
.brand-text {
  font-size: 20px;
  font-weight: 800;
  letter-spacing: .5px;
  white-space: nowrap;
}
.brand-text em {
  font-style: normal;
  font-size: 13px;
  margin-left: 4px;
  padding: 2px 8px;
  border-radius: 999px;
  color: #fff;
  background: linear-gradient(135deg, var(--ac-orange), var(--ac-orange-deep));
  vertical-align: 3px;
}
.main-nav {
  display: flex;
  align-items: center;
  gap: 6px;
}
.nav-link {
  padding: 8px 16px;
  border-radius: 999px;
  font-size: 15px;
  font-weight: 600;
  color: var(--ac-ink-soft);
  transition: color .25s, background .25s;
}
.nav-link:hover { color: var(--ac-orange-deep); background: rgba(255, 146, 0, .1); }
.nav-link.is-current { color: var(--ac-orange-deep); }
.nav-cta {
  color: #fff !important;
  background: linear-gradient(135deg, var(--ac-orange), var(--ac-orange-deep));
  box-shadow: 0 6px 16px rgba(232, 100, 12, .35);
}
.nav-cta:hover { transform: translateY(-1px); box-shadow: 0 8px 20px rgba(232, 100, 12, .45); }

.nav-toggle {
  display: none;
  flex-direction: column;
  justify-content: center;
  gap: 5px;
  width: 42px;
  height: 42px;
  border: none;
  border-radius: 10px;
  background: rgba(255, 146, 0, .12);
  cursor: pointer;
}
.nav-toggle span {
  display: block;
  width: 20px;
  height: 2.5px;
  margin: 0 auto;
  border-radius: 2px;
  background: var(--ac-orange-deep);
  transition: transform .3s, opacity .3s;
}
.nav-toggle.is-open span:nth-child(1) { transform: translateY(7.5px) rotate(45deg); }
.nav-toggle.is-open span:nth-child(2) { opacity: 0; }
.nav-toggle.is-open span:nth-child(3) { transform: translateY(-7.5px) rotate(-45deg); }

/* ---------------- 首屏 Hero ---------------- */
.hero {
  position: relative;
  padding: calc(var(--header-h) + 60px) 0 90px;
  background: linear-gradient(160deg, #ffb52e 0%, var(--ac-orange) 45%, var(--ac-orange-deep) 100%);
  overflow: hidden;
}
/* 放射光芒，呼应 Logo 背景 */
.hero-rays {
  position: absolute;
  inset: -50%;
  background: repeating-conic-gradient(
    from 0deg at 50% 40%,
    rgba(255, 255, 255, .10) 0deg 8deg,
    transparent 8deg 20deg
  );
  animation: rays-spin 60s linear infinite;
  pointer-events: none;
}
@keyframes rays-spin { to { transform: rotate(360deg); } }

.hero-inner {
  position: relative;
  display: grid;
  grid-template-columns: 1.05fr .95fr;
  align-items: center;
  gap: 48px;
}
.hero-copy { color: #fff; }
.hero-tag {
  display: inline-block;
  padding: 6px 16px;
  border-radius: 999px;
  font-size: 14px;
  font-weight: 600;
  background: rgba(255, 255, 255, .18);
  border: 1px solid rgba(255, 255, 255, .35);
  backdrop-filter: blur(6px);
}
.hero-title {
  margin: 20px 0 16px;
  font-size: clamp(34px, 4.6vw, 56px);
  line-height: 1.2;
  font-weight: 900;
  text-shadow: 0 4px 18px rgba(194, 83, 10, .45);
}
.hero-title span { color: #fff3d6; }
.hero-desc {
  max-width: 34em;
  font-size: 16.5px;
  color: rgba(255, 255, 255, .92);
}
.hero-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 22px;
}
.meta-badge {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 8px 16px;
  border-radius: 999px;
  font-size: 14px;
  color: #fff;
  background: rgba(0, 0, 0, .18);
  border: 1px solid rgba(255, 255, 255, .25);
}
.meta-badge b { color: var(--ac-yellow); }
.meta-badge .dot {
  width: 8px; height: 8px;
  border-radius: 50%;
  background: var(--ac-yellow);
  box-shadow: 0 0 8px var(--ac-yellow);
  animation: pulse 1.8s ease-in-out infinite;
}
@keyframes pulse { 50% { opacity: .4; } }

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 14px;
  margin-top: 28px;
}
.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 14px 30px;
  border-radius: 999px;
  font-size: 16px;
  font-weight: 700;
  transition: transform .25s, box-shadow .25s, background .25s;
}
.btn-primary {
  color: var(--ac-orange-deep);
  background: #fff;
  box-shadow: 0 12px 28px rgba(120, 45, 0, .35);
}
.btn-primary:hover { transform: translateY(-3px); box-shadow: 0 16px 36px rgba(120, 45, 0, .45); }
.btn-ghost {
  color: #fff;
  border: 2px solid rgba(255, 255, 255, .7);
}
.btn-ghost:hover { background: rgba(255, 255, 255, .15); transform: translateY(-3px); }

.hero-points {
  display: flex;
  flex-wrap: wrap;
  gap: 10px 22px;
  margin-top: 26px;
  font-size: 14px;
  color: rgba(255, 255, 255, .9);
}
.hero-points li { position: relative; padding-left: 18px; }
.hero-points li::before {
  content: "";
  position: absolute;
  left: 0; top: .48em;
  width: 9px; height: 9px;
  border-radius: 3px;
  background: var(--ac-yellow);
}

/* ---- 截图展示（悬停切换） ---- */
.shots {
  position: relative;
  display: flex;
  justify-content: center;
  align-items: flex-end;
  padding-bottom: 44px;
}
.shot {
  position: relative;
  width: 32%;
  max-width: 200px;
  cursor: pointer;
  transition: transform .45s cubic-bezier(.22, 1, .36, 1), opacity .45s, filter .45s;
  transform: translateY(26px) scale(.88);
  opacity: .55;
  filter: saturate(.7);
  z-index: 1;
}
.shot + .shot { margin-left: -4%; }
.shot.is-active {
  transform: translateY(-8px) scale(1.06);
  opacity: 1;
  filter: none;
  z-index: 3;
}
.phone {
  position: relative;
  aspect-ratio: 9 / 18.5;
  border-radius: 26px;
  padding: 10px;
  background: #2b2118;
  box-shadow: 0 24px 50px rgba(90, 35, 0, .45), inset 0 0 0 2px rgba(255, 255, 255, .08);
}
/* 刘海 */
.phone::before {
  content: "";
  position: absolute;
  top: 16px; left: 50%;
  transform: translateX(-50%);
  width: 34%; height: 5px;
  border-radius: 3px;
  background: rgba(255, 255, 255, .22);
  z-index: 2;
}
.phone img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  border-radius: 18px;
  /* src 留空时的占位背景 */
  background:
    linear-gradient(160deg, rgba(255, 197, 61, .35), rgba(255, 146, 0, .12)),
    repeating-linear-gradient(45deg, rgba(255, 255, 255, .05) 0 12px, transparent 12px 24px),
    #3d2f22;
}
.shot figcaption {
  margin-top: 12px;
  text-align: center;
  font-size: 13.5px;
  font-weight: 600;
  color: rgba(255, 255, 255, .85);
  opacity: 0;
  transform: translateY(6px);
  transition: opacity .4s, transform .4s;
}
.shot.is-active figcaption { opacity: 1; transform: none; }
.shots-tip {
  position: absolute;
  bottom: 0; left: 50%;
  transform: translateX(-50%);
  font-size: 12.5px;
  letter-spacing: 1px;
  color: rgba(255, 255, 255, .65);
  white-space: nowrap;
}

/* ---------------- 通用区块 ---------------- */
.section { padding: 96px 0; }
.section-head { text-align: center; margin-bottom: 52px; }
.section-kicker {
  display: inline-block;
  font-size: 13px;
  font-weight: 800;
  letter-spacing: 3px;
  color: var(--ac-orange-deep);
  padding: 5px 16px;
  border-radius: 999px;
  background: rgba(255, 146, 0, .12);
}
.section-title {
  margin-top: 14px;
  font-size: clamp(28px, 3.4vw, 40px);
  font-weight: 900;
}
.section-sub { margin-top: 10px; color: var(--ac-ink-soft); }

/* ---------------- 功能特色 ---------------- */
.features { background: linear-gradient(180deg, var(--ac-bg), #fff 30%, #fff 70%, var(--ac-bg)); }
.feature-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}
.feature-card {
  padding: 34px 28px;
  border-radius: var(--radius-lg);
  background: var(--ac-card);
  border: 1px solid rgba(255, 146, 0, .15);
  box-shadow: var(--shadow-soft);
  transition: transform .35s, box-shadow .35s, border-color .35s;
}
.feature-card:hover {
  transform: translateY(-8px);
  box-shadow: var(--shadow-pop);
  border-color: rgba(255, 146, 0, .4);
}
.feature-icon {
  width: 56px; height: 56px;
  display: grid;
  place-items: center;
  border-radius: 16px;
  color: #fff;
  background: linear-gradient(135deg, var(--ac-yellow), var(--ac-orange-deep));
  box-shadow: 0 8px 18px rgba(232, 100, 12, .3);
}
.feature-icon svg { width: 30px; height: 30px; }
.feature-card h3 { margin: 18px 0 8px; font-size: 19px; }
.feature-card p { font-size: 14.5px; color: var(--ac-ink-soft); }

/* ---------------- 用户评价 ---------------- */
.review-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 24px;
}
.review-card {
  position: relative;
  padding: 30px 28px;
  border-radius: var(--radius-lg);
  background: var(--ac-card);
  border: 1px solid rgba(255, 146, 0, .15);
  box-shadow: var(--shadow-soft);
  transition: transform .35s, box-shadow .35s;
}
.review-card:hover { transform: translateY(-6px); box-shadow: var(--shadow-pop); }
.review-stars {
  color: var(--ac-yellow);
  font-size: 18px;
  letter-spacing: 3px;
  text-shadow: 0 2px 6px rgba(255, 197, 61, .5);
}
.review-text { margin: 14px 0 20px; color: var(--ac-ink); font-size: 15.5px; }
.review-user {
  display: flex;
  align-items: center;
  gap: 12px;
  padding-top: 16px;
  border-top: 1px dashed rgba(255, 146, 0, .25);
}
/* 汉字头像（不使用 img） */
.avatar {
  flex-shrink: 0;
  width: 46px; height: 46px;
  display: grid;
  place-items: center;
  border-radius: 50%;
  font-size: 20px;
  font-weight: 800;
  color: #fff;
  background: linear-gradient(135deg, var(--av, var(--ac-orange)), var(--ac-orange-deep));
  box-shadow: 0 6px 14px rgba(232, 100, 12, .3);
  user-select: none;
}
.review-user b { display: block; font-size: 15px; }
.review-user small { color: var(--ac-ink-soft); font-size: 12.5px; }

/* ---------------- 常见问题 ---------------- */
.faq { background: linear-gradient(180deg, var(--ac-bg), #fff 40%, var(--ac-bg)); }
.faq-item {
  margin-bottom: 14px;
  border-radius: var(--radius-md);
  background: var(--ac-card);
  border: 1px solid rgba(255, 146, 0, .18);
  box-shadow: var(--shadow-soft);
  overflow: hidden;
  transition: border-color .3s, box-shadow .3s;
}
.faq-item[open] {
  border-color: rgba(255, 146, 0, .45);
  box-shadow: var(--shadow-pop);
}
.faq-item summary {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  padding: 20px 24px;
  font-size: 16.5px;
  font-weight: 700;
  cursor: pointer;
  list-style: none;
  transition: color .25s;
}
.faq-item summary::-webkit-details-marker { display: none; }
.faq-item summary:hover { color: var(--ac-orange-deep); }
.faq-arrow {
  flex-shrink: 0;
  width: 26px; height: 26px;
  border-radius: 50%;
  background: rgba(255, 146, 0, .14);
  position: relative;
  transition: transform .35s, background .35s;
}
.faq-arrow::before {
  content: "";
  position: absolute;
  inset: 0;
  margin: auto;
  width: 8px; height: 8px;
  border-right: 2.4px solid var(--ac-orange-deep);
  border-bottom: 2.4px solid var(--ac-orange-deep);
  transform: translateY(-2px) rotate(45deg);
}
.faq-item[open] .faq-arrow { transform: rotate(180deg); background: rgba(255, 146, 0, .3); }
.faq-body {
  padding: 0 24px 22px;
  color: var(--ac-ink-soft);
  font-size: 15px;
}

/* ---------------- 下载区域（重点） ---------------- */
.download {
  position: relative;
  padding: 110px 0;
  text-align: center;
  color: #fff;
  background: linear-gradient(150deg, #ffb52e 0%, var(--ac-orange) 40%, var(--ac-orange-deep) 85%, var(--ac-orange-dark) 100%);
  overflow: hidden;
}
.dl-rays {
  position: absolute;
  inset: -50%;
  background: repeating-conic-gradient(
    from 0deg at 50% 50%,
    rgba(255, 255, 255, .12) 0deg 7deg,
    transparent 7deg 18deg
  );
  animation: rays-spin 50s linear infinite reverse;
  pointer-events: none;
}
.dl-inner { position: relative; }
.dl-logo {
  width: 96px; height: 96px;
  margin: 0 auto 22px;
  border-radius: 26px;
  object-fit: cover;
  background: linear-gradient(135deg, var(--ac-yellow), #fff);
  box-shadow: 0 16px 40px rgba(120, 45, 0, .4);
  animation: bob 3.2s ease-in-out infinite;
}
@keyframes bob { 50% { transform: translateY(-10px); } }
.dl-title {
  font-size: clamp(30px, 4vw, 46px);
  font-weight: 900;
  text-shadow: 0 4px 18px rgba(120, 45, 0, .4);
}
.dl-sub {
  margin-top: 12px;
  font-size: 17px;
  color: rgba(255, 255, 255, .92);
}
.dl-meta {
  display: inline-flex;
  flex-wrap: wrap;
  justify-content: center;
  align-items: center;
  gap: 14px;
  margin-top: 24px;
  padding: 10px 24px;
  border-radius: 999px;
  font-size: 14px;
  background: rgba(0, 0, 0, .18);
  border: 1px solid rgba(255, 255, 255, .25);
}
.dl-meta b { color: var(--ac-yellow); }
.dl-meta-divider { width: 1px; height: 14px; background: rgba(255, 255, 255, .35); }

.dl-buttons {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 20px;
  margin-top: 38px;
}
.dl-btn {
  display: inline-flex;
  align-items: center;
  gap: 14px;
  min-width: 250px;
  padding: 16px 30px;
  border-radius: 18px;
  color: var(--ac-orange-deep);
  background: #fff;
  box-shadow: 0 14px 34px rgba(120, 45, 0, .4);
  transition: transform .3s, box-shadow .3s;
}
.dl-btn:hover {
  transform: translateY(-5px) scale(1.03);
  box-shadow: 0 22px 46px rgba(120, 45, 0, .5);
}
.dl-btn svg { flex-shrink: 0; }
.dl-btn-text { text-align: left; }
.dl-btn-text small { display: block; font-size: 12.5px; color: var(--ac-ink-soft); }
.dl-btn-text b { display: block; font-size: 19px; letter-spacing: .5px; }
.dl-btn-ios { color: #1d1b16; }

.dl-note {
  margin-top: 26px;
  font-size: 13.5px;
  letter-spacing: 1px;
  color: rgba(255, 255, 255, .75);
}

/* ---------------- 页脚 ---------------- */
.site-footer {
  padding: 46px 0 34px;
  background: #241a10;
  color: rgba(255, 255, 255, .75);
}
.footer-inner {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 18px;
  text-align: center;
}
.footer-brand .brand-text { color: #fff; }
.footer-nav {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 6px 22px;
  font-size: 14.5px;
}
.footer-nav a { transition: color .25s; }
.footer-nav a:hover { color: var(--ac-yellow); }
.footer-copy { font-size: 13px; color: rgba(255, 255, 255, .45); }

/* ---------------- 滚动入场动画 ---------------- */
.reveal {
  opacity: 0;
  transform: translateY(34px);
  transition: opacity .7s ease, transform .7s cubic-bezier(.22, 1, .36, 1);
}
.reveal.in { opacity: 1; transform: none; }
.feature-grid .reveal:nth-child(2) { transition-delay: .08s; }
.feature-grid .reveal:nth-child(3) { transition-delay: .16s; }
.feature-grid .reveal:nth-child(5) { transition-delay: .08s; }
.feature-grid .reveal:nth-child(6) { transition-delay: .16s; }
.review-grid .reveal:nth-child(2) { transition-delay: .08s; }
.review-grid .reveal:nth-child(3) { transition-delay: .16s; }
.review-grid .reveal:nth-child(4) { transition-delay: .24s; }

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { animation: none !important; transition: none !important; }
  .reveal { opacity: 1; transform: none; }
}

/* ---------------- 响应式 ---------------- */
@media (max-width: 1024px) {
  .hero-inner { grid-template-columns: 1fr; gap: 64px; text-align: center; }
  .hero-copy { display: flex; flex-direction: column; align-items: center; }
  .hero-points { justify-content: center; }
  .feature-grid { grid-template-columns: repeat(2, 1fr); }
}

@media (max-width: 768px) {
  .section { padding: 72px 0; }
  .nav-toggle { display: flex; }
  .main-nav {
    position: fixed;
    top: var(--header-h);
    left: 0; right: 0;
    flex-direction: column;
    align-items: stretch;
    gap: 4px;
    padding: 16px 5%;
    background: rgba(255, 247, 236, .97);
    backdrop-filter: blur(12px);
    box-shadow: 0 14px 30px rgba(232, 100, 12, .18);
    transform: translateY(-12px);
    opacity: 0;
    pointer-events: none;
    transition: transform .3s, opacity .3s;
  }
  .main-nav.is-open { transform: none; opacity: 1; pointer-events: auto; }
  .nav-link { padding: 13px 18px; text-align: center; }
  .review-grid { grid-template-columns: 1fr; }
  .dl-btn { width: 100%; max-width: 340px; justify-content: center; }
}

@media (max-width: 560px) {
  .feature-grid { grid-template-columns: 1fr; }
  .hero { padding-bottom: 70px; }
  .shots { padding-bottom: 38px; }
  .shot { max-width: 150px; }
  .hero-actions .btn { width: 100%; justify-content: center; }
  .dl-meta { gap: 10px; padding: 10px 16px; }
}