/* ============================================================
   Acfan流鼻血版 · 单页官网样式
   主题：橙红热血（贴合 AcFan 品牌图标）
   ============================================================ */
:root {
  --brand: #ff5a2d;          /* 主橙红 */
  --brand-deep: #e8430f;
  --brand-soft: #fff1ea;
  --ink: #1f2230;
  --ink-soft: #5b6072;
  --line: #eceef3;
  --bg: #ffffff;
  --bg-alt: #fafbfd;
  --radius: 16px;
  --shadow: 0 10px 30px rgba(255, 90, 45, .12);
  --maxw: 1180px;
}

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

html { scroll-behavior: smooth; }

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC",
    "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  color: var(--ink);
  background: var(--bg);
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
}

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

.container {
  width: 100%;
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 0 24px;
}
.container-narrow { max-width: 860px; }

/* ---------- 按钮 ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 12px 26px;
  border-radius: 999px;
  font-weight: 600;
  font-size: 15px;
  border: none;
  cursor: pointer;
  transition: transform .15s ease, box-shadow .15s ease, background .15s ease;
  white-space: nowrap;
}
.btn:active { transform: scale(.97); }
.btn-primary {
  background: linear-gradient(135deg, var(--brand), var(--brand-deep));
  color: #fff;
  box-shadow: var(--shadow);
}
.btn-primary:hover { transform: translateY(-2px); box-shadow: 0 14px 34px rgba(255,90,45,.28); }
.btn-ghost {
  background: transparent;
  color: var(--ink);
  border: 1.5px solid var(--line);
}
.btn-ghost:hover { border-color: var(--brand); color: var(--brand); }
.btn-light {
  background: #fff;
  color: var(--brand-deep);
}
.btn-lg { padding: 15px 34px; font-size: 16px; }

/* ---------- 顶部导航 ---------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(255,255,255,.92);
  backdrop-filter: saturate(180%) blur(12px);
  border-bottom: 1px solid var(--line);
}
.nav-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 68px;
}
.brand { display: flex; align-items: center; gap: 10px; }
.brand-logo { width: 38px; height: 38px; border-radius: 10px; }
.brand-name { font-weight: 700; font-size: 18px; }
.nav-links { display: flex; gap: 28px; }
.nav-links a {
  font-size: 15px;
  color: var(--ink-soft);
  transition: color .15s;
}
.nav-links a:hover { color: var(--brand); }
.nav-download { padding: 9px 20px; font-size: 14px; }

.nav-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 8px;
}
.nav-toggle span {
  width: 22px; height: 2px; background: var(--ink); border-radius: 2px;
  transition: .2s;
}

/* ---------- Hero ---------- */
.hero {
  background:
    radial-gradient(1200px 500px at 85% -10%, var(--brand-soft), transparent 60%),
    linear-gradient(180deg, #fffdfb 0%, #fff 100%);
  overflow: hidden;
}
.hero-inner {
  display: grid;
  grid-template-columns: 1.05fr .95fr;
  align-items: center;
  gap: 40px;
  padding: 72px 24px 64px;
}
.hero-eyebrow {
  color: var(--brand);
  font-weight: 700;
  letter-spacing: 3px;
  font-size: 13px;
  margin-bottom: 14px;
}
.hero h1 {
  font-size: 44px;
  line-height: 1.25;
  font-weight: 800;
  letter-spacing: -.5px;
}
.hl {
  background: linear-gradient(120deg, var(--brand), #ff8a3d);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}
.hero-sub {
  margin-top: 18px;
  font-size: 17px;
  color: var(--ink-soft);
  max-width: 480px;
}
.hero-actions { margin-top: 30px; display: flex; gap: 14px; flex-wrap: wrap; }
.hero-meta {
  margin-top: 22px;
  list-style: none;
  display: flex;
  gap: 22px;
  color: var(--ink-soft);
  font-size: 14px;
}
.hero-meta li::before {
  content: "✓";
  color: var(--brand);
  font-weight: 700;
  margin-right: 6px;
}
.hero-visual { display: flex; justify-content: center; }
.hero-img {
  max-height: 540px;
  border-radius: 24px;
  box-shadow: 0 30px 60px rgba(31,34,48,.18);
}

/* ---------- 通用 section ---------- */
.section { padding: 80px 0; }
.section-alt { background: var(--bg-alt); }
.section-tag {
  color: var(--brand);
  font-weight: 700;
  letter-spacing: 2px;
  font-size: 13px;
  margin-bottom: 12px;
}
.section-title {
  font-size: 32px;
  font-weight: 800;
  letter-spacing: -.3px;
}
.section-desc {
  margin-top: 12px;
  color: var(--ink-soft);
  font-size: 16px;
  max-width: 640px;
}

/* ---------- 四宫格功能 ---------- */
.grid-4 {
  margin-top: 40px;
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 20px;
}
.feature-card {
  background: #fff;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 28px 24px;
  transition: transform .2s, box-shadow .2s, border-color .2s;
}
.feature-card:hover {
  transform: translateY(-6px);
  border-color: var(--brand);
  box-shadow: var(--shadow);
}
.feature-no {
  display: inline-block;
  font-size: 13px;
  font-weight: 700;
  color: var(--brand);
  background: var(--brand-soft);
  padding: 3px 10px;
  border-radius: 999px;
  margin-bottom: 16px;
}
.feature-card h3 { font-size: 19px; margin-bottom: 8px; }
.feature-card p { color: var(--ink-soft); font-size: 14.5px; }

/* ---------- 应用展示 ---------- */
.show-row {
  margin-top: 48px;
  display: grid;
  grid-template-columns: .8fr 1.2fr;
  gap: 40px;
  align-items: center;
}
.show-row.reverse { grid-template-columns: 1.2fr .8fr; }
.show-row.reverse .show-text { order: 2; }
.show-text h3 { font-size: 26px; font-weight: 800; margin-bottom: 12px; }
.show-text p { color: var(--ink-soft); font-size: 16px; }
.show-media img {
  border-radius: 20px;
  box-shadow: 0 20px 45px rgba(31,34,48,.16);
}

/* ---------- 追番看板 ---------- */
.board {
  margin-top: 36px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  overflow: hidden;
  background: #fff;
}
.board-item {
  display: grid;
  grid-template-columns: 130px 1fr auto;
  gap: 20px;
  align-items: center;
  padding: 22px 28px;
  border-bottom: 1px solid var(--line);
}
.board-item:last-child { border-bottom: none; }
.board-time { color: var(--ink-soft); font-size: 14px; }
.board-item h4 { font-size: 17px; }
.board-item p { color: var(--ink-soft); font-size: 14px; }
.board-tag {
  font-size: 12.5px;
  font-weight: 700;
  color: var(--brand);
  background: var(--brand-soft);
  padding: 4px 12px;
  border-radius: 999px;
}
.board-item.empty { background: var(--bg-alt); color: var(--ink-soft); }

/* ---------- FAQ ---------- */
.faq-list { margin-top: 32px; display: grid; gap: 14px; }
.faq-item {
  background: #fff;
  border: 1px solid var(--line);
  border-radius: 14px;
  padding: 0 22px;
}
.faq-item summary {
  cursor: pointer;
  list-style: none;
  font-weight: 600;
  font-size: 16.5px;
  padding: 18px 0;
  position: relative;
  padding-right: 30px;
}
.faq-item summary::-webkit-details-marker { display: none; }
.faq-item summary::after {
  content: "+";
  position: absolute;
  right: 0; top: 50%;
  transform: translateY(-50%);
  font-size: 22px;
  color: var(--brand);
  transition: transform .2s;
}
.faq-item[open] summary::after { transform: translateY(-50%) rotate(45deg); }
.faq-item p {
  padding: 0 0 18px;
  color: var(--ink-soft);
  font-size: 15px;
}

/* ---------- 用户评价 ---------- */
.grid-3 {
  margin-top: 36px;
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
}
.review-card {
  background: #fff;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 24px;
}
.review-card p { color: var(--ink); font-size: 15px; margin-bottom: 18px; }
.review-meta { display: flex; align-items: center; gap: 12px; }
.avatar {
  width: 38px; height: 38px;
  border-radius: 50%;
  background: var(--brand-soft);
  color: var(--brand);
  display: flex; align-items: center; justify-content: center;
  font-weight: 700;
}
.review-meta b { display: block; font-size: 14px; }
.review-meta small { color: var(--ink-soft); font-size: 12.5px; }

/* ---------- CTA ---------- */
.cta {
  background: linear-gradient(135deg, var(--brand) 0%, var(--brand-deep) 100%);
  color: #fff;
  padding: 72px 0;
}
.cta-inner { text-align: center; }
.cta h2 { font-size: 32px; font-weight: 800; }
.cta p { margin: 12px 0 28px; opacity: .92; font-size: 16px; }

/* ---------- 页脚 ---------- */
.site-footer {
  background: #16181f;
  color: #a9adbd;
  padding: 40px 0;
  font-size: 14px;
}
.footer-inner { text-align: center; }
.footer-brand {
  display: flex; align-items: center; justify-content: center;
  gap: 10px; margin-bottom: 14px; color: #fff; font-weight: 600;
}
.footer-copy { margin-top: 10px; opacity: .7; font-size: 12.5px; }

/* ---------- 悬浮下载 ---------- */
.float-download {
  position: fixed;
  right: 18px; bottom: 22px;
  z-index: 99;
  background: linear-gradient(135deg, var(--brand), var(--brand-deep));
  color: #fff;
  padding: 14px 26px;
  border-radius: 999px;
  font-weight: 700;
  box-shadow: 0 12px 30px rgba(255,90,45,.4);
  display: none;
}

/* ---------- 响应式 ---------- */
@media (max-width: 960px) {
  .hero-inner { grid-template-columns: 1fr; padding: 48px 24px; }
  .hero h1 { font-size: 32px; }
  .hero-img { max-height: 420px; margin: 0 auto; }
  .grid-4 { grid-template-columns: repeat(2, 1fr); }
  .grid-3 { grid-template-columns: 1fr 1fr; }
  .show-row, .show-row.reverse { grid-template-columns: 1fr; gap: 20px; }
  .show-row.reverse .show-text { order: 0; }
  .board-item { grid-template-columns: 1fr; gap: 6px; }
  .board-tag { justify-self: start; }
}

@media (max-width: 680px) {
  .nav-links {
    position: absolute;
    top: 68px; left: 0; right: 0;
    background: #fff;
    flex-direction: column;
    gap: 0;
    border-bottom: 1px solid var(--line);
    max-height: 0;
    overflow: hidden;
    transition: max-height .25s ease;
  }
  .nav-links.open { max-height: 320px; }
  .nav-links a { padding: 14px 24px; border-top: 1px solid var(--line); }
  .nav-toggle { display: flex; }
  .nav-download { display: none; }
  .grid-4, .grid-3 { grid-template-columns: 1fr; }
  .section { padding: 56px 0; }
  .section-title { font-size: 26px; }
  .float-download { display: inline-flex; }
}