/* ============================================================
   mufy - AI角色扮演聊天软件 单页样式
   移动端优先 · 清爽薄荷青主题（Fresh Mint-Teal）
   ============================================================ */

/* ---------- Reset & Base ---------- */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

:root {
  /* 主色：teal → cyan 渐变（清爽薄荷青） */
  --c-primary: #0d9488;
  --c-primary-dark: #0f766e;
  --c-primary-light: #06b6d4;
  --c-cyan: #22d3ee;
  --c-mint: #99f6e4;
  /* 强调色：coral 珊瑚红（CTA 按钮） */
  --c-accent: #f43f5e;
  /* 渐变 */
  --grad-main: linear-gradient(135deg, var(--c-primary) 0%, var(--c-primary-light) 100%);
  --grad-cta: linear-gradient(135deg, var(--c-accent) 0%, #fb7185 100%);
  /* 文本 */
  --c-text: #0f2a2e;
  --c-text-soft: #4b6b6f;
  --c-text-mute: #8aa5a8;
  /* 背景 */
  --c-bg: #f6fdfb;
  --c-bg-alt: #ecfdf7;
  --c-card: #ffffff;
  --c-border: #d6f0ea;
  /* 圆角与阴影 */
  --radius: 18px;
  --radius-sm: 12px;
  --shadow-sm: 0 2px 12px rgba(13, 148, 136, 0.06);
  --shadow: 0 10px 30px rgba(13, 148, 136, 0.10);
  --shadow-lg: 0 22px 60px rgba(13, 148, 136, 0.18);
  --maxw: 1180px;
  --header-h: 62px;
}

html { scroll-behavior: smooth; scroll-padding-top: var(--header-h); -webkit-text-size-adjust: 100%; }

body {
  font-family: -apple-system, BlinkMacSystemFont, "PingFang SC", "Microsoft YaHei", "Helvetica Neue", "Segoe UI", sans-serif;
  font-size: 16px;
  line-height: 1.65;
  color: var(--c-text);
  background: var(--c-bg);
  -webkit-font-smoothing: antialiased;
  -webkit-tap-highlight-color: transparent; /* 移除移动端点击高亮闪烁 */
  overflow-x: clip;
  word-break: break-word; /* 防止长 URL/英文串溢出 */
  padding-bottom: calc(80px + env(safe-area-inset-bottom)); /* 适配 iPhone 底部安全区 */
}

img { max-width: 100%; height: auto; display: block; }
a { color: var(--c-primary); text-decoration: none; -webkit-tap-highlight-color: transparent; }
a:hover { text-decoration: underline; }
ul, ol { list-style: none; }
button, .btn, .nav-toggle, .faq-item summary, .float-download { touch-action: manipulation; /* 消除移动端 300ms 点击延迟 */ }

/* ---------- Layout ---------- */
.container { width: 100%; max-width: var(--maxw); margin: 0 auto; padding: 0 18px; }
.container-narrow { max-width: 840px; }

.section { padding: 52px 0; }
.section-alt { background: var(--c-bg-alt); }

.section-head { text-align: center; max-width: 700px; margin: 0 auto 34px; }
.section-eyebrow {
  display: inline-block; font-size: 13px; font-weight: 600; letter-spacing: 0.08em;
  color: var(--c-primary); background: rgba(13, 148, 136, 0.10);
  padding: 6px 16px; border-radius: 999px; margin-bottom: 14px;
}
.section-head h2 { font-size: 26px; line-height: 1.32; margin-bottom: 12px; color: var(--c-text); }
.section-desc { color: var(--c-text-soft); font-size: 15px; }

/* ---------- Buttons ---------- */
.btn {
  display: inline-flex; align-items: center; justify-content: center;
  font-size: 15px; font-weight: 600; padding: 13px 26px; border-radius: 999px;
  border: none; cursor: pointer; white-space: nowrap;
  transition: transform 0.18s ease, box-shadow 0.18s ease, background 0.18s ease;
  text-decoration: none;
}
.btn:hover { text-decoration: none; transform: translateY(-2px); }
.btn:active { transform: translateY(0); }
.btn-primary { background: var(--grad-cta); color: #fff; box-shadow: 0 8px 22px rgba(244, 63, 94, 0.30); }
.btn-primary:hover { box-shadow: 0 12px 30px rgba(244, 63, 94, 0.42); }
.btn-ghost { background: rgba(255, 255, 255, 0.18); color: #fff; border: 1px solid rgba(255, 255, 255, 0.45); -webkit-backdrop-filter: blur(6px); backdrop-filter: blur(6px); }
.btn-ghost:hover { background: rgba(255, 255, 255, 0.28); }
.btn-sm { padding: 9px 18px; font-size: 14px; }
.btn-lg { padding: 16px 36px; font-size: 16px; }

/* ---------- Header ---------- */
.site-header {
  position: sticky; top: 0; z-index: 100;
  background: rgba(246, 253, 251, 0.86);
  -webkit-backdrop-filter: saturate(180%) blur(14px);
  backdrop-filter: saturate(180%) blur(14px);
  border-bottom: 1px solid var(--c-border);
  transition: box-shadow 0.25s ease;
}
.site-header.scrolled { box-shadow: 0 4px 18px rgba(13, 148, 136, 0.08); }
.header-inner { display: flex; align-items: center; justify-content: space-between; height: var(--header-h); }
.brand { display: flex; align-items: center; gap: 10px; color: var(--c-text); }
.brand:hover { text-decoration: none; }
.brand-logo { width: 34px; height: 34px; border-radius: 9px; object-fit: cover; box-shadow: var(--shadow-sm); }
.brand-name { font-size: 21px; font-weight: 800; letter-spacing: -0.02em; background: var(--grad-main); -webkit-background-clip: text; background-clip: text; -webkit-text-fill-color: transparent; }

.main-nav { display: none; gap: 28px; }
.main-nav a { color: var(--c-text-soft); font-size: 15px; font-weight: 500; position: relative; }
.main-nav a:hover { color: var(--c-primary); text-decoration: none; }
.main-nav a::after {
  content: ""; position: absolute; left: 0; bottom: -6px; width: 0; height: 2px;
  background: var(--grad-main); border-radius: 2px; transition: width 0.22s ease;
}
.main-nav a:hover::after { width: 100%; }
.nav-download { display: none; }

/* 移动端导航展开态（汉堡按钮触发 .open） */
@media (max-width: 959px) {
  .main-nav {
    position: absolute; top: var(--header-h); left: 0; right: 0;
    flex-direction: column; gap: 0;
    background: rgba(246, 253, 251, 0.98);
    -webkit-backdrop-filter: saturate(180%) blur(14px);
    backdrop-filter: saturate(180%) blur(14px);
    border-bottom: 1px solid var(--c-border);
    box-shadow: 0 12px 30px rgba(13, 148, 136, 0.10);
    padding: 8px 18px 14px;
    max-height: 0; overflow: hidden; opacity: 0;
    transition: max-height 0.28s ease, opacity 0.22s ease, padding 0.28s ease;
    pointer-events: none;
  }
  .main-nav.open { max-height: 420px; opacity: 1; pointer-events: auto; }
  .main-nav a {
    width: 100%; padding: 12px 4px; font-size: 16px;
    border-bottom: 1px solid var(--c-border);
    min-height: 44px; /* 移动端可点击区域 ≥ 44px */
  }
  .main-nav a:last-child { border-bottom: none; }
  .main-nav a::after { display: none; }
}

/* 汉堡按钮 */
.nav-toggle {
  display: inline-flex; flex-direction: column; gap: 5px;
  width: 40px; height: 40px; align-items: center; justify-content: center;
  cursor: pointer; background: none; border: none; padding: 0;
}
.nav-toggle span { display: block; width: 22px; height: 2px; background: var(--c-text); border-radius: 2px; transition: transform 0.25s ease, opacity 0.25s ease; }
.nav-toggle[aria-expanded="true"] span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
.nav-toggle[aria-expanded="true"] span:nth-child(2) { opacity: 0; }
.nav-toggle[aria-expanded="true"] span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

/* ---------- Hero ---------- */
.hero {
  position: relative;
  background:
    radial-gradient(1100px 560px at 85% -8%, rgba(34, 211, 238, 0.30), transparent),
    radial-gradient(900px 500px at 8% 8%, rgba(13, 148, 136, 0.32), transparent),
    linear-gradient(160deg, #042f2e 0%, #0d5c54 50%, #0e7490 100%);
  color: #fff; padding: 48px 0 60px; overflow: hidden;
}
/* 浮动光斑（薄荷青气泡） */
.hero::before, .hero::after {
  content: ""; position: absolute; border-radius: 50%; filter: blur(60px);
  opacity: 0.55; pointer-events: none; z-index: 0;
}
.hero::before { width: 280px; height: 280px; background: radial-gradient(circle, rgba(153, 246, 228, 0.7), transparent 70%); top: 8%; left: -8%; animation: floatOrb 9s ease-in-out infinite; }
.hero::after { width: 240px; height: 240px; background: radial-gradient(circle, rgba(34, 211, 238, 0.6), transparent 70%); bottom: 4%; right: -6%; animation: floatOrb 11s ease-in-out infinite 1.2s; }

.hero-inner { position: relative; z-index: 1; display: flex; flex-direction: column; gap: 30px; align-items: center; text-align: center; }
.hero-eyebrow {
  position: relative; overflow: hidden; font-size: 13px; letter-spacing: 0.06em; color: #e0fbf6;
  background: rgba(255, 255, 255, 0.10); border: 1px solid rgba(255, 255, 255, 0.20);
  padding: 7px 18px; border-radius: 999px; display: inline-block; margin-bottom: 18px;
  animation: fadeInUp 0.7s ease-out 0.10s both;
}
.hero-eyebrow::after {
  content: ""; position: absolute; top: 0; left: 0; bottom: 0; width: 40%;
  background: linear-gradient(100deg, transparent, rgba(255,255,255,0.55), transparent);
  animation: shimmer 4.5s ease-in-out infinite 1s;
}
.hero-text h1 { font-size: 30px; line-height: 1.3; font-weight: 800; letter-spacing: -0.01em; margin-bottom: 16px; animation: fadeInUp 0.7s ease-out 0.20s both; }
.hero-text h1 strong {
  background: linear-gradient(90deg, #99f6e4, #22d3ee, #99f6e4); background-size: 200% 100%;
  -webkit-background-clip: text; background-clip: text; -webkit-text-fill-color: transparent;
  animation: gradientShift 4s linear infinite;
}
.hero-sub { font-size: 15px; color: #c8ece4; max-width: 580px; margin: 0 auto; animation: fadeInUp 0.7s ease-out 0.30s both; }
.hero-sub strong { color: #fff; }
.hero-cta { display: flex; flex-wrap: wrap; gap: 12px; justify-content: center; margin-top: 26px; animation: fadeInUp 0.7s ease-out 0.40s both; }
.hero-cta .btn-primary { animation: ctaPulse 2.6s ease-in-out infinite 0.8s; }
.hero-stats { display: flex; gap: 22px; justify-content: center; margin-top: 34px; flex-wrap: wrap; animation: fadeInUp 0.7s ease-out 0.50s both; }
.hero-stats dt { font-size: 26px; font-weight: 800; background: linear-gradient(90deg, #fff, #99f6e4); -webkit-background-clip: text; background-clip: text; -webkit-text-fill-color: transparent; }
.hero-stats dd { font-size: 13px; color: #9fd8cd; }
.hero-stats > div { animation: popIn 0.6s cubic-bezier(.34,1.56,.64,1) both; }
.hero-stats > div:nth-child(1) { animation-delay: 0.50s; }
.hero-stats > div:nth-child(2) { animation-delay: 0.64s; }
.hero-stats > div:nth-child(3) { animation-delay: 0.78s; }
.hero-stats > div:nth-child(4) { animation-delay: 0.92s; }

.hero-visual { position: relative; width: 210px; margin: 14px auto 0; animation: fadeInUp 0.8s ease-out 0.35s both; }
.hero-visual::before {
  content: ""; position: absolute; inset: -8% -6%; z-index: 0;
  background: radial-gradient(circle at 50% 45%, rgba(153,246,228,0.55), rgba(34,211,238,0.25) 45%, transparent 70%);
  filter: blur(30px); border-radius: 40% 60% 55% 45% / 50% 45% 55% 50%;
  animation: pulseGlow 3.6s ease-in-out infinite;
}
.hero-visual > img:not(.hero-visual-sub) {
  position: relative; z-index: 2; display: block; width: 100%; height: auto;
  border-radius: 24px; box-shadow: var(--shadow-lg);
  animation: floatMain 5s ease-in-out infinite; will-change: transform;
}
.hero-visual .hero-visual-sub {
  position: absolute; top: 26px; width: 74%; border-radius: 22px; box-shadow: var(--shadow);
  opacity: 0.5; filter: blur(0.5px); z-index: 1; display: none;
}
.hero-visual .hero-visual-sub1 { left: -12%; animation: floatSubLeft 5s ease-in-out infinite; }
.hero-visual .hero-visual-sub2 { left: auto; right: -12%; animation: floatSubRight 5.5s ease-in-out infinite 0.6s; }

@keyframes floatMain { 0%,100%{transform:translateY(0) rotate(0)} 25%{transform:translateY(-12px) rotate(-1deg)} 50%{transform:translateY(-16px) rotate(0)} 75%{transform:translateY(-8px) rotate(1deg)} }
@keyframes floatSubLeft { 0%,100%{transform:translateY(0) rotate(-6deg)} 50%{transform:translateY(-10px) rotate(-6deg)} }
@keyframes floatSubRight { 0%,100%{transform:translateY(0) rotate(6deg)} 50%{transform:translateY(-12px) rotate(6deg)} }
@keyframes fadeInUp { from{opacity:0;transform:translateY(22px)} to{opacity:1;transform:translateY(0)} }
@keyframes popIn { 0%{opacity:0;transform:translateY(18px) scale(0.92)} 70%{opacity:1;transform:translateY(0) scale(1.04)} 100%{opacity:1;transform:translateY(0) scale(1)} }
@keyframes floatOrb { 0%,100%{transform:translate(0,0) scale(1)} 50%{transform:translate(20px,-26px) scale(1.08)} }
@keyframes pulseGlow { 0%,100%{opacity:0.45;transform:scale(1)} 50%{opacity:0.85;transform:scale(1.06)} }
@keyframes gradientShift { 0%{background-position:0% 50%} 100%{background-position:200% 50%} }
@keyframes shimmer { 0%{transform:translateX(-120%)} 100%{transform:translateX(220%)} }
@keyframes ctaPulse { 0%,100%{box-shadow:0 8px 24px rgba(244,63,94,0.45),0 0 0 0 rgba(244,63,94,0.5)} 50%{box-shadow:0 10px 30px rgba(244,63,94,0.6),0 0 0 10px rgba(244,63,94,0)} }

/* ---------- Features ---------- */
.feature-grid { display: grid; grid-template-columns: 1fr; gap: 16px; }
.feature-card {
  background: var(--c-card); border: 1px solid var(--c-border); border-radius: var(--radius);
  padding: 26px 22px; box-shadow: var(--shadow-sm);
  transition: transform 0.2s ease, box-shadow 0.2s ease, border-color 0.2s ease;
}
.feature-card:hover { transform: translateY(-4px); box-shadow: var(--shadow); border-color: var(--c-mint); }
.feature-icon {
  width: 52px; height: 52px; border-radius: 14px; background: var(--grad-main); color: #fff;
  display: flex; align-items: center; justify-content: center; margin-bottom: 16px;
  box-shadow: 0 6px 16px rgba(13, 148, 136, 0.25);
}
.feature-card h3 { font-size: 18px; margin-bottom: 8px; color: var(--c-text); }
.feature-card p { font-size: 14px; color: var(--c-text-soft); }

/* ---------- Characters ---------- */
.character-grid { display: grid; grid-template-columns: repeat(2, 1fr); gap: 14px; }
.character-card {
  background: var(--c-card); border: 1px solid var(--c-border); border-radius: var(--radius);
  overflow: hidden; box-shadow: var(--shadow-sm); padding: 18px 14px; text-align: center;
  transition: transform 0.2s ease, box-shadow 0.2s ease, border-color 0.2s ease;
}
.character-card:hover { transform: translateY(-4px); box-shadow: var(--shadow); border-color: var(--c-mint); }
.character-card img, .character-avatar-fallback {
  width: 88px; height: 88px; border-radius: 50%; margin: 0 auto 12px; object-fit: cover;
  border: 3px solid transparent; background-clip: padding-box;
}
.character-avatar-fallback {
  display: flex; align-items: center; justify-content: center;
  font-size: 32px; font-weight: 700; color: #fff;
  background: var(--grad-main);
}
.character-card h3 { font-size: 16px; margin-bottom: 4px; color: var(--c-text); }
.character-tag { display: inline-block; font-size: 12px; color: var(--c-primary); background: rgba(13,148,136,0.10); padding: 2px 10px; border-radius: 999px; margin-bottom: 8px; }
.character-card p { font-size: 13px; color: var(--c-text-soft); line-height: 1.5; }
.character-note { text-align: center; color: var(--c-text-mute); font-size: 14px; margin-top: 22px; }

/* ---------- Scenes ---------- */
.scene-list { display: grid; grid-template-columns: 1fr; gap: 20px; }
.scene-card {
  background: var(--c-card); border-radius: var(--radius); overflow: hidden;
  box-shadow: var(--shadow-sm); border: 1px solid var(--c-border);
  transition: transform 0.2s ease, box-shadow 0.2s ease, border-color 0.2s ease;
}
.scene-card:hover { transform: translateY(-4px); box-shadow: var(--shadow); border-color: var(--c-mint); }
.scene-card img { width: 100%; aspect-ratio: 16 / 9; object-fit: cover; }
.scene-body { padding: 22px; }
.scene-body h3 { font-size: 18px; margin-bottom: 8px; color: var(--c-text); }
.scene-body p { font-size: 14px; color: var(--c-text-soft); }

/* ---------- Demo ---------- */
.demo-inner { display: flex; flex-direction: column; gap: 32px; align-items: center; }
.demo-text { max-width: 640px; text-align: center; }
.demo-text .section-eyebrow { margin-bottom: 14px; }
.demo-text h2 { font-size: 24px; line-height: 1.35; margin-bottom: 12px; color: var(--c-text); }
.demo-desc { color: var(--c-text-soft); font-size: 15px; }
.chat-demo { display: flex; flex-direction: column; gap: 14px; width: 100%; max-width: 460px; }
.bubble { display: flex; gap: 10px; align-items: flex-start; max-width: 100%; }
.bubble-user { justify-content: flex-end; }
.bubble-text {
  padding: 12px 16px; border-radius: 18px; font-size: 14px; line-height: 1.55;
  max-width: 80%; word-break: break-word;
}
.bubble-user .bubble-text { background: var(--grad-main); color: #fff; border-bottom-right-radius: 6px; box-shadow: var(--shadow-sm); }
.bubble-ai .bubble-text { background: var(--c-card); color: var(--c-text); border: 1px solid var(--c-border); border-bottom-left-radius: 6px; box-shadow: var(--shadow-sm); }
.bubble-avatar {
  width: 36px; height: 36px; border-radius: 50%; flex-shrink: 0;
  display: flex; align-items: center; justify-content: center;
  font-size: 16px; font-weight: 700; color: #fff; background: var(--grad-cta);
}

/* ---------- Tutorial ---------- */
.tutorial-list { display: grid; grid-template-columns: 1fr; gap: 16px; counter-reset: step; }
.tutorial-step {
  background: var(--c-card); border: 1px solid var(--c-border); border-radius: var(--radius);
  padding: 24px 22px; box-shadow: var(--shadow-sm); position: relative;
  transition: transform 0.2s ease, box-shadow 0.2s ease;
}
.tutorial-step:hover { transform: translateY(-3px); box-shadow: var(--shadow); }
.tutorial-num {
  width: 40px; height: 40px; border-radius: 50%; background: var(--grad-main); color: #fff;
  display: flex; align-items: center; justify-content: center; font-weight: 800; font-size: 17px;
  margin-bottom: 14px; box-shadow: 0 4px 12px rgba(13, 148, 136, 0.3);
}
.tutorial-step h3 { font-size: 17px; margin-bottom: 6px; color: var(--c-text); }
.tutorial-step p { font-size: 14px; color: var(--c-text-soft); }

/* ---------- Compare ---------- */
.compare-table-wrap { overflow-x: auto; -webkit-overflow-scrolling: touch; border-radius: var(--radius); box-shadow: var(--shadow-sm); border: 1px solid var(--c-border); position: relative; }
.compare-table-wrap::after {
  /* 移动端横向可滚动提示渐变（右侧渐隐） */
  content: ""; position: absolute; top: 0; right: 0; bottom: 0; width: 28px;
  background: linear-gradient(to right, transparent, rgba(255,255,255,0.85));
  pointer-events: none; opacity: 0; transition: opacity 0.2s ease;
}
@media (max-width: 639px) { .compare-table-wrap::after { opacity: 1; } }
.compare-table { width: 100%; border-collapse: collapse; min-width: 560px; background: var(--c-card); }
.compare-table th, .compare-table td { padding: 14px 16px; text-align: left; font-size: 14px; border-bottom: 1px solid var(--c-border); }
.compare-table thead th { background: var(--grad-main); color: #fff; font-weight: 600; font-size: 15px; }
.compare-table thead th:first-child { border-top-left-radius: 0; }
.compare-table tbody tr:last-child td { border-bottom: none; }
.compare-table tbody tr:nth-child(even) { background: var(--c-bg-alt); }
.compare-table td:nth-child(2) { color: var(--c-primary-dark); font-weight: 600; }
.compare-table td:nth-child(3) { color: var(--c-text-mute); }

/* ---------- Reviews ---------- */
.review-summary {
  display: flex; flex-direction: column; align-items: center; gap: 6px;
  margin: 0 auto 30px; padding: 22px 28px; background: var(--c-card);
  border-radius: var(--radius); box-shadow: var(--shadow-sm); border: 1px solid var(--c-border);
  max-width: 360px; text-align: center;
}
.review-score { font-size: 40px; font-weight: 800; line-height: 1; background: var(--grad-cta); -webkit-background-clip: text; background-clip: text; -webkit-text-fill-color: transparent; }
.review-stars { color: #fbbf24; font-size: 18px; letter-spacing: 2px; }
.review-count { font-size: 13px; color: var(--c-text-mute); }
.review-grid { display: grid; grid-template-columns: 1fr; gap: 16px; }
.review-card {
  background: var(--c-card); border: 1px solid var(--c-border); border-radius: var(--radius);
  padding: 22px 20px; box-shadow: var(--shadow-sm);
  transition: transform 0.2s ease, box-shadow 0.2s ease;
}
.review-card:hover { transform: translateY(-3px); box-shadow: var(--shadow); }
.review-card .review-stars { margin-bottom: 10px; }
.review-card p { font-size: 14px; color: var(--c-text-soft); line-height: 1.6; margin-bottom: 12px; }
.review-card footer { font-size: 13px; color: var(--c-text-mute); font-weight: 600; }

/* ---------- Updates / Timeline ---------- */
.timeline { position: relative; padding-left: 24px; }
.timeline::before {
  content: ""; position: absolute; left: 7px; top: 6px; bottom: 6px; width: 2px;
  background: linear-gradient(to bottom, var(--c-primary), var(--c-primary-light)); border-radius: 2px;
}
.timeline-item { position: relative; margin-bottom: 24px; }
.timeline-item:last-child { margin-bottom: 0; }
.timeline-item::before {
  content: ""; position: absolute; left: -22px; top: 6px; width: 14px; height: 14px;
  border-radius: 50%; background: var(--c-card); border: 3px solid var(--c-primary); box-shadow: 0 0 0 4px rgba(13,148,136,0.12);
}
.timeline-date { font-size: 13px; color: var(--c-primary); font-weight: 700; margin-bottom: 6px; }
.timeline-item h3 { font-size: 17px; margin-bottom: 6px; color: var(--c-text); }
.timeline-item p { font-size: 14px; color: var(--c-text-soft); }

/* ---------- FAQ ---------- */
.faq-list { display: flex; flex-direction: column; gap: 12px; }
.faq-item {
  background: var(--c-card); border: 1px solid var(--c-border); border-radius: var(--radius-sm);
  box-shadow: var(--shadow-sm); overflow: hidden; transition: box-shadow 0.2s ease, border-color 0.2s ease;
}
.faq-item[open] { box-shadow: var(--shadow); border-color: var(--c-mint); }
.faq-item summary {
  cursor: pointer; padding: 16px 20px; font-size: 15px; font-weight: 600; color: var(--c-text);
  list-style: none; position: relative; padding-right: 44px;
}
.faq-item summary::-webkit-details-marker { display: none; }
.faq-item summary::after {
  content: ""; position: absolute; right: 20px; top: 50%; width: 10px; height: 10px;
  border-right: 2px solid var(--c-primary); border-bottom: 2px solid var(--c-primary);
  transform: translateY(-65%) rotate(45deg); transition: transform 0.25s ease;
}
.faq-item[open] summary::after { transform: translateY(-35%) rotate(-135deg); }
.faq-answer { padding: 0 20px 18px; }
.faq-answer p { font-size: 14px; color: var(--c-text-soft); line-height: 1.7; }

/* ---------- Download ---------- */
.download-section {
  background:
    radial-gradient(900px 480px at 90% 10%, rgba(34, 211, 238, 0.18), transparent),
    radial-gradient(700px 400px at 5% 90%, rgba(13, 148, 136, 0.20), transparent),
    linear-gradient(160deg, #042f2e 0%, #0d5c54 55%, #0e7490 100%);
  color: #fff; border-radius: 0; padding: 56px 0;
}
.download-inner { display: flex; flex-direction: column; gap: 28px; align-items: center; text-align: center; }
.download-text { max-width: 640px; }
.download-text .section-eyebrow { background: rgba(255,255,255,0.16); color: #e0fbf6; }
.download-text h2 { font-size: 26px; margin-bottom: 12px; color: #fff; }
.download-desc { font-size: 15px; color: #c8ece4; margin-bottom: 22px; }
.download-desc strong { color: #fff; }
.download-meta { text-align: left; background: rgba(255,255,255,0.08); border: 1px solid rgba(255,255,255,0.18); border-radius: var(--radius-sm); padding: 16px 20px; margin-bottom: 22px; -webkit-backdrop-filter: blur(6px); backdrop-filter: blur(6px); }
.download-meta ul { display: grid; grid-template-columns: 1fr; gap: 8px; }
.download-meta li { font-size: 14px; color: #d6f5ee; }
.download-meta li strong { color: #fff; }
.download-cta { display: flex; flex-direction: column; align-items: center; gap: 12px; }
.download-hint { font-size: 13px; color: #9fd8cd; max-width: 460px; line-height: 1.6; }
.download-visual { order: -1; }
.download-visual img { width: 110px; height: 110px; border-radius: 24px; box-shadow: var(--shadow-lg); object-fit: cover; }

/* ---------- Footer ---------- */
.site-footer { background: #06231f; color: #b6d3cd; padding: 40px 0 24px; }
.footer-grid { display: grid; grid-template-columns: 1fr; gap: 28px; margin-bottom: 28px; }
.footer-brand .brand { color: #fff; margin-bottom: 12px; }
.footer-brand .brand-logo { box-shadow: none; }
.footer-brand .brand-name { background: linear-gradient(90deg, #99f6e4, #22d3ee); -webkit-background-clip: text; background-clip: text; -webkit-text-fill-color: transparent; }
.footer-brand p { font-size: 14px; line-height: 1.7; color: #8fb8b1; }
.footer-logo { width: 32px; height: 32px; border-radius: 8px; object-fit: cover; }
.footer-nav h4 { font-size: 15px; color: #fff; margin-bottom: 12px; font-weight: 600; }
.footer-nav a { display: block; font-size: 14px; color: #8fb8b1; padding: 4px 0; }
.footer-nav a:hover { color: var(--c-mint); text-decoration: none; }
.footer-bottom { border-top: 1px solid rgba(255,255,255,0.08); padding-top: 18px; text-align: center; }
.footer-bottom p { font-size: 12px; color: #6fa098; line-height: 1.8; }
.footer-bottom p + p { margin-top: 6px; }

/* ---------- Float download ---------- */
.float-download {
  position: fixed; right: 16px; bottom: calc(16px + env(safe-area-inset-bottom));
  z-index: 90; padding: 12px 20px; font-size: 14px; font-weight: 600;
  background: var(--grad-cta); color: #fff; border-radius: 999px;
  box-shadow: 0 8px 24px rgba(244, 63, 94, 0.4);
  display: inline-flex; align-items: center; gap: 6px;
  transition: opacity 0.3s ease, transform 0.3s ease;
}
.float-download:hover { text-decoration: none; transform: translateY(-2px); }
.float-download.hidden { opacity: 0; transform: translateY(20px); pointer-events: none; }

/* ---------- 浮动下载按钮内的箭头小图标 ---------- */
.float-download::before { content: "↓"; font-size: 16px; line-height: 1; }

/* ============================================================
   响应式断点
   ============================================================ */

/* ---------- 平板 ≥ 640px ---------- */
@media (min-width: 640px) {
  :root { --header-h: 66px; }
  .section { padding: 64px 0; }
  .section-head h2 { font-size: 30px; }
  .section-desc { font-size: 16px; }
  .hero { padding: 64px 0 76px; }
  .hero-text h1 { font-size: 38px; }
  .hero-sub { font-size: 16px; }
  .hero-visual { width: 260px; }
  .hero-visual .hero-visual-sub { display: block; }
  .hero-stats dt { font-size: 30px; }
  .feature-grid { grid-template-columns: repeat(2, 1fr); gap: 18px; }
  .character-grid { grid-template-columns: repeat(3, 1fr); gap: 16px; }
  .scene-list { grid-template-columns: repeat(3, 1fr); gap: 22px; }
  .tutorial-list { grid-template-columns: repeat(2, 1fr); gap: 18px; }
  .review-grid { grid-template-columns: repeat(2, 1fr); gap: 18px; }
  .download-meta ul { grid-template-columns: 1fr 1fr; }
  .download-text h2 { font-size: 30px; }
  .footer-grid { grid-template-columns: 2fr 1fr 1fr; gap: 36px; }
}

/* ---------- 桌面 ≥ 960px ---------- */
@media (min-width: 960px) {
  :root { --header-h: 72px; }
  .section { padding: 76px 0; }
  .section-head { margin-bottom: 40px; }
  .section-head h2 { font-size: 34px; }
  .hero { padding: 80px 0 96px; }
  .hero-inner { flex-direction: row; text-align: left; gap: 48px; }
  .hero-text { flex: 1.1; }
  .hero-visual { flex: 0 0 280px; width: 280px; margin: 0; }
  .hero-cta { justify-content: flex-start; }
  .hero-stats { justify-content: flex-start; }
  .hero-text h1 { font-size: 44px; }
  .hero-sub { margin-left: 0; }
  .feature-grid { grid-template-columns: repeat(3, 1fr); gap: 22px; }
  .character-grid { grid-template-columns: repeat(3, 1fr); }
  .tutorial-list { grid-template-columns: repeat(4, 1fr); }
  .review-grid { grid-template-columns: repeat(4, 1fr); }
  .demo-inner { flex-direction: row; text-align: left; align-items: center; gap: 48px; }
  .demo-text { text-align: left; flex: 1; }
  .demo-visual { flex: 0 0 460px; }
  .download-inner { flex-direction: row; text-align: left; align-items: center; gap: 48px; }
  .download-text { flex: 1.2; }
  .download-visual { order: 0; flex: 0 0 160px; }
  .download-visual img { width: 160px; height: 160px; }
  .download-cta { align-items: flex-start; }
  .download-meta { max-width: 100%; }
  .download-hint { margin: 0; }
  /* 桌面端显示主导航与下载按钮 */
  .main-nav { display: flex; }
  .nav-download { display: inline-flex; }
  .nav-toggle { display: none; }
}

/* ---------- 超大桌面 ≥ 1100px ---------- */
@media (min-width: 1100px) {
  .hero-visual { flex: 0 0 320px; width: 320px; }
}

/* ---------- 小屏 ≤ 360px 优化 ---------- */
@media (max-width: 360px) {
  :root { --header-h: 56px; }
  body { font-size: 15px; }
  .container { padding: 0 14px; }
  .section { padding: 40px 0; } /* 小屏压缩垂直间距 */
  .hero { padding: 36px 0 44px; }
  .hero-text h1 { font-size: 24px; }
  .hero-eyebrow { font-size: 12px; padding: 6px 14px; }
  .hero-stats { gap: 16px; margin-top: 28px; }
  .hero-stats dt { font-size: 22px; }
  .hero-stats dd { font-size: 12px; }
  .hero-visual { width: 180px; }
  .section-head { margin-bottom: 26px; }
  .section-head h2 { font-size: 21px; }
  .section-desc { font-size: 14px; }
  /* 角色卡片保持 2 列，避免 9 张卡片单列过长 */
  .character-grid { grid-template-columns: repeat(2, 1fr); gap: 10px; }
  .character-card { padding: 14px 10px; }
  .character-card img, .character-avatar-fallback { width: 72px; height: 72px; }
  .character-avatar-fallback { font-size: 26px; }
  .character-card h3 { font-size: 15px; }
  .character-card p { font-size: 12px; }
  .character-tag { font-size: 11px; padding: 2px 8px; }
  .feature-card { padding: 20px 16px; }
  .feature-card h3 { font-size: 16px; }
  .feature-icon { width: 46px; height: 46px; }
  .review-score { font-size: 34px; }
  .download-section { padding: 40px 0; }
  .download-text h2 { font-size: 22px; }
  .float-download { font-size: 13px; padding: 10px 16px; right: 12px; bottom: 12px; }
}

/* ============================================================
   可访问性：用户偏好减少动效时
   仅禁用装饰性动画，保留核心 hero 动画（float / ctaPulse）以保证视觉重点
   ============================================================ */
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.001ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.001ms !important;
    scroll-behavior: auto !important;
  }
  /* 重新启用 hero 核心动画（图片浮动 + CTA 脉冲），保证首屏视觉重点 */
  .hero-visual > img:not(.hero-visual-sub) { animation: floatMain 5s ease-in-out infinite !important; }
  .hero-cta .btn-primary { animation: ctaPulse 2.6s ease-in-out infinite 0.8s !important; }
}