:root {
    --primary: #7c3aed;
    --primary-light: #9d5cf5;
    --primary-dark: #5b21b6;
    --accent: #f59e0b;
    --accent-light: #fbbf24;
    --bg-dark: #0f0e17;
    --bg-card: #1a1826;
    --bg-card2: #221f35;
    --text: #e2e0f0;
    --text-muted: #9490b5;
    --border: #2e2a45;
    --radius: 12px;
    --shadow: 0 8px 32px rgba(0,0,0,0.4);
  }
  *, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
  html { scroll-behavior: smooth; }
  body { font-family: 'PingFang SC','Microsoft YaHei',sans-serif; background: var(--bg-dark); color: var(--text); line-height: 1.6; font-size: 16px; }
  a { text-decoration: none; color: inherit; }
  img { max-width: 100%; }

  /* ── Navbar ── */
  .navbar {
    position: fixed; top: 0; left: 0; right: 0; z-index: 999;
    background: rgba(15,14,23,0.92); backdrop-filter: blur(12px);
    border-bottom: 1px solid var(--border);
    display: flex; align-items: center; justify-content: space-between;
    padding: 0 40px; height: 64px;
  }
  .nav-logo { display: flex; align-items: center; gap: 10px; font-size: 1.3rem; font-weight: 700; color: #fff; }
  .nav-logo span { color: var(--accent); }
  .nav-logo .logo-icon { width: 36px; height: 36px; background: linear-gradient(135deg,var(--primary),var(--accent)); border-radius: 8px; display: flex; align-items: center; justify-content: center; font-size: 1rem; }
  .nav-links { display: flex; align-items: center; gap: 4px; }
  .nav-item { position: relative; }
  .nav-item > a {
    display: flex; align-items: center; gap: 4px;
    padding: 8px 14px; border-radius: 6px;
    font-size: 1rem; color: var(--text-muted);
    transition: all .2s;
  }
  .nav-item > a:hover { background: var(--bg-card); color: #fff; }
  .nav-item .chevron { font-size: 0.7rem; transition: transform .2s; }
  .nav-item:hover .chevron { transform: rotate(180deg); }
  .dropdown {
    position: absolute; top: calc(100% + 8px); left: 0;
    background: var(--bg-card); border: 1px solid var(--border);
    border-radius: var(--radius); min-width: 160px;
    box-shadow: var(--shadow); opacity: 0; pointer-events: none;
    transform: translateY(-6px); transition: all .2s;
  }
  .nav-item:hover .dropdown { opacity: 1; pointer-events: auto; transform: translateY(0); }
  .dropdown a { display: block; padding: 10px 16px; font-size: 0.95rem; color: var(--text-muted); transition: all .15s; }
  .dropdown a:hover { background: var(--bg-card2); color: var(--accent); }
  .nav-cta {
    padding: 8px 20px; background: var(--accent); color: #000 !important;
    font-weight: 700; border-radius: 6px; font-size: 0.95rem;
    transition: background .2s;
  }
  .nav-cta:hover { background: var(--accent-light) !important; }

  /* ── Hero ── */
  .hero {
    min-height: 100vh; display: flex; align-items: center; justify-content: center;
    position: relative; overflow: hidden; text-align: center;
    padding: 100px 20px 60px;
  }
  .hero-bg {
    position: absolute; inset: 0;
    background:
      radial-gradient(ellipse 70% 60% at 20% 60%, rgba(124,58,237,0.4) 0%, transparent 65%),
      radial-gradient(ellipse 60% 70% at 80% 35%, rgba(245,158,11,0.18) 0%, transparent 55%),
      radial-gradient(ellipse 50% 50% at 50% 90%, rgba(91,33,182,0.25) 0%, transparent 60%),
      linear-gradient(160deg, #0d0b1e 0%, #12102a 40%, #0f0e17 100%);
  }
  .hero-bg::after {
    content: ''; position: absolute; inset: 0;
    background-image: radial-gradient(circle at 1px 1px, rgba(124,58,237,0.12) 1px, transparent 0);
    background-size: 44px 44px;
  }
  .hero-content { position: relative; z-index: 1; max-width: 800px; }
  .hero-badge {
    display: inline-flex; align-items: center; gap: 8px;
    background: rgba(245,158,11,0.15); border: 1px solid rgba(245,158,11,0.4);
    color: var(--accent); padding: 7px 18px; border-radius: 999px;
    font-size: 0.95rem; font-weight: 600; margin-bottom: 24px;
  }
  .hero h1 { font-size: clamp(2rem, 5vw, 3.5rem); font-weight: 800; color: #fff; line-height: 1.2; margin-bottom: 20px; }
  .hero h1 em { font-style: normal; color: var(--accent); }
  .hero h2 { font-size: clamp(1.3rem, 3vw, 2rem); font-weight: 600; color: rgba(255,255,255,0.7); margin-bottom: 20px; }
  .hero p { font-size: 1.15rem; color: var(--text-muted); margin-bottom: 36px; max-width: 600px; margin-left: auto; margin-right: auto; }
  .hero-btns { display: flex; gap: 16px; justify-content: center; flex-wrap: wrap; margin-bottom: 56px; }
  .btn-primary { padding: 14px 32px; background: var(--primary); color: #fff; font-weight: 700; border-radius: 8px; font-size: 1.05rem; transition: all .2s; }
  .btn-primary:hover { background: var(--primary-light); transform: translateY(-2px); box-shadow: 0 8px 24px rgba(124,58,237,0.5); }
  .btn-outline { padding: 14px 32px; border: 2px solid var(--accent); color: var(--accent); font-weight: 700; border-radius: 8px; font-size: 1.05rem; transition: all .2s; }
  .btn-outline:hover { background: rgba(245,158,11,0.1); transform: translateY(-2px); }
  .hero-stats { display: flex; gap: 40px; justify-content: center; flex-wrap: wrap; }
  .hero-stat h3 { font-size: 2.2rem; font-weight: 800; color: var(--accent); }
  .hero-stat p { font-size: 0.95rem; color: var(--text-muted); }

  /* ── Section common ── */
  section { padding: 80px 20px; }
  .container { max-width: 1200px; margin: 0 auto; }
  .section-label { font-size: 0.875rem; font-weight: 700; letter-spacing: .1em; text-transform: uppercase; color: var(--accent); margin-bottom: 12px; }
  .section-title { font-size: clamp(1.7rem, 3vw, 2.3rem); font-weight: 800; color: #fff; margin-bottom: 16px; }
  .section-sub { color: var(--text-muted); font-size: 1.05rem; max-width: 600px; }
  .section-header { margin-bottom: 48px; }
  .section-header.center { text-align: center; }
  .section-header.center .section-sub { margin: 0 auto; }

  /* ── Features ── */
  .features { background: var(--bg-card); }
  .features-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 20px; }
  @media (max-width: 1100px) { .features-grid { grid-template-columns: repeat(2, 1fr); } }
  @media (max-width: 600px)  { .features-grid { grid-template-columns: 1fr; } }
  .feature-card {
    background: var(--bg-dark); border: 1px solid var(--border);
    border-radius: var(--radius); padding: 28px 22px;
    transition: all .25s;
  }
  .feature-card:hover { border-color: var(--primary); transform: translateY(-4px); box-shadow: 0 12px 40px rgba(124,58,237,0.2); }
  .feature-icon { width: 52px; height: 52px; border-radius: 10px; display: flex; align-items: center; justify-content: center; font-size: 1.5rem; margin-bottom: 16px; }
  .feature-card h3 { font-size: 1.1rem; font-weight: 700; color: #fff; margin-bottom: 10px; }
  .feature-card p { font-size: 0.95rem; color: var(--text-muted); line-height: 1.75; }

  /* ── Pricing ── */
  .pricing { background: var(--bg-dark); }
  .pricing-tabs { display: flex; gap: 8px; flex-wrap: wrap; margin-bottom: 32px; justify-content: center; }
  .tab-btn {
    padding: 11px 24px; border-radius: 8px; border: 1px solid var(--border);
    background: var(--bg-card); color: var(--text-muted); font-size: 1rem;
    cursor: pointer; transition: all .2s; white-space: nowrap;
  }
  .tab-btn.active, .tab-btn:hover { background: var(--primary); color: #fff; border-color: var(--primary); }

  /* Slider */
  .pricing-slider-container { overflow: hidden; }
  .pricing-slider {
    display: flex;
    transition: transform 0.42s cubic-bezier(0.4, 0, 0.2, 1);
    will-change: transform;
    cursor: grab;
    user-select: none;
  }
  .pricing-slider:active { cursor: grabbing; }
  .pricing-panel { min-width: 100%; display: block; }

  .pricing-scroll { overflow-x: auto; padding-bottom: 16px; }
  .pricing-scroll::-webkit-scrollbar { height: 6px; }
  .pricing-scroll::-webkit-scrollbar-track { background: var(--bg-card); border-radius: 3px; }
  .pricing-scroll::-webkit-scrollbar-thumb { background: var(--primary); border-radius: 3px; }
  .pricing-cards { display: flex; gap: 20px; padding: 4px 2px 12px; justify-content: center; flex-wrap: wrap; }
  .price-card {
    width: 210px; flex-shrink: 0;
    background: var(--bg-card); border: 1px solid var(--border);
    border-radius: var(--radius); padding: 26px 20px; position: relative;
    transition: all .25s;
  }
  .price-card:hover { border-color: var(--primary); transform: translateY(-4px); box-shadow: 0 12px 40px rgba(124,58,237,0.25); }
  .price-card.featured { border-color: var(--accent); background: linear-gradient(145deg, var(--bg-card2), rgba(245,158,11,0.07)); }
  .price-badge { position: absolute; top: -12px; left: 50%; transform: translateX(-50%); background: var(--accent); color: #000; font-size: 0.85rem; font-weight: 700; padding: 3px 14px; border-radius: 999px; white-space: nowrap; }
  .price-name { font-size: 0.9rem; color: var(--text-muted); margin-bottom: 8px; }
  .price-amount { font-size: 2rem; font-weight: 800; color: #fff; margin-bottom: 4px; }
  .price-amount span { font-size: 1rem; color: var(--text-muted); font-weight: 400; }
  .price-divider { border: none; border-top: 1px solid var(--border); margin: 14px 0; }
  .price-specs { list-style: none; margin-bottom: 18px; }
  .price-specs li { font-size: 0.9rem; color: var(--text-muted); padding: 4px 0; display: flex; align-items: center; gap: 6px; }
  .price-specs li::before { content: '✓'; color: var(--primary-light); font-size: 0.85rem; }
  .price-card.featured .price-specs li::before { color: var(--accent); }
  .btn-buy {
    display: block; text-align: center; width: 100%;
    padding: 11px; background: var(--primary); color: #fff;
    font-weight: 700; font-size: 1rem; border-radius: 6px; transition: all .2s;
  }
  .btn-buy:hover { background: var(--primary-light); }
  .price-card.featured .btn-buy { background: var(--accent); color: #000; }
  .price-card.featured .btn-buy:hover { background: var(--accent-light); }

  /* Slider dots */
  .slider-dots { display: flex; justify-content: center; gap: 8px; margin-top: 20px; }
  .slider-dot {
    width: 28px; height: 6px; border-radius: 3px;
    background: var(--border); cursor: pointer; transition: all .25s;
  }
  .slider-dot.active { background: var(--primary); width: 44px; }

  /* ── About ── */
  .about { background: var(--bg-card); }
  .about-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 60px; align-items: center; }
  .about-img { border-radius: 16px; overflow: hidden; box-shadow: var(--shadow); }
  .about-img img { width: 100%; height: 400px; object-fit: cover; display: block; }
  .about-text p { color: var(--text-muted); margin-bottom: 24px; line-height: 1.85; font-size: 1rem; }
  .about-stats { display: grid; grid-template-columns: 1fr 1fr; gap: 16px; margin-top: 32px; }
  .about-stat { background: var(--bg-dark); border: 1px solid var(--border); border-radius: 10px; padding: 18px 20px; }
  .about-stat h4 { font-size: 1.7rem; font-weight: 800; color: var(--accent); }
  .about-stat p { font-size: 0.9rem; color: var(--text-muted); margin: 0; }

  /* ── Use Cases ── */
  .usecases { background: var(--bg-dark); }
  .usecases-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 20px; }
  @media (max-width: 1100px) { .usecases-grid { grid-template-columns: repeat(2, 1fr); } }
  @media (max-width: 600px)  { .usecases-grid { grid-template-columns: 1fr; } }
  .usecase-card {
    background: var(--bg-card); border: 1px solid var(--border);
    border-radius: var(--radius); padding: 28px 22px; transition: all .25s;
    display: flex; flex-direction: column; gap: 12px;
  }
  .usecase-card:hover { border-color: var(--accent); transform: translateY(-4px); }
  .usecase-icon { font-size: 2.2rem; }
  .usecase-card h3 { font-size: 1.1rem; font-weight: 700; color: #fff; }
  .usecase-card p { font-size: 0.95rem; color: var(--text-muted); line-height: 1.75; }

  /* ── Payment ── */
  .payment { background: var(--bg-card); }
  .payment-grid { display: flex; gap: 20px; flex-wrap: wrap; justify-content: center; }
  .payment-card {
    background: var(--bg-dark); border: 1px solid var(--border);
    border-radius: var(--radius); padding: 28px 32px; text-align: center;
    min-width: 160px; flex: 1; max-width: 200px; transition: all .25s;
  }
  .payment-card:hover { border-color: var(--primary); transform: translateY(-4px); }
  .payment-icon { font-size: 2.4rem; margin-bottom: 10px; }
  .payment-card h4 { font-size: 1rem; font-weight: 700; color: #fff; }
  .payment-card p { font-size: 0.875rem; color: var(--text-muted); margin-top: 4px; }

  /* ── FAQ ── */
  .faq { background: var(--bg-dark); }
  .faq-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 16px; }
  .faq-item {
    background: var(--bg-card); border: 1px solid var(--border);
    border-radius: var(--radius); overflow: hidden;
  }
  .faq-q {
    display: flex; justify-content: space-between; align-items: center;
    padding: 18px 22px; cursor: pointer; font-weight: 600; color: #fff; font-size: 1rem;
    transition: background .15s;
  }
  .faq-q:hover { background: var(--bg-card2); }
  .faq-q .arrow { font-size: 0.8rem; color: var(--accent); transition: transform .2s; flex-shrink: 0; margin-left: 12px; }
  .faq-item.open .faq-q .arrow { transform: rotate(180deg); }
  .faq-a { display: none; padding: 14px 22px 18px; font-size: 0.95rem; color: var(--text-muted); line-height: 1.85; border-top: 1px solid var(--border); }
  .faq-item.open .faq-a { display: block; }

  /* ── CTA Banner ── */
  .cta-banner {
    background: linear-gradient(135deg, var(--primary-dark), var(--primary), rgba(245,158,11,0.3));
    padding: 80px 20px; text-align: center;
  }
  .cta-banner h2 { font-size: clamp(1.7rem, 3vw, 2.5rem); font-weight: 800; color: #fff; margin-bottom: 16px; }
  .cta-banner p { color: rgba(255,255,255,0.78); margin-bottom: 36px; font-size: 1.05rem; }
  .cta-btns { display: flex; gap: 16px; justify-content: center; flex-wrap: wrap; }

  /* ── Footer ── */
  footer { background: #080710; border-top: 1px solid var(--border); padding: 60px 20px 30px; }
  .footer-grid { display: grid; grid-template-columns: 1.5fr repeat(4, 1fr); gap: 40px; margin-bottom: 48px; }
  .footer-brand .logo { display: flex; align-items: center; gap: 10px; font-size: 1.25rem; font-weight: 700; color: #fff; margin-bottom: 16px; }
  .footer-brand .logo span { color: var(--accent); }
  .footer-brand p { font-size: 0.95rem; color: var(--text-muted); line-height: 1.85; margin-bottom: 20px; }
  .footer-socials { display: flex; gap: 10px; }
  .social-btn {
    width: 38px; height: 38px; border-radius: 8px;
    background: var(--bg-card); border: 1px solid var(--border);
    display: flex; align-items: center; justify-content: center;
    font-size: 1.1rem; transition: all .2s;
  }
  .social-btn:hover { background: var(--primary); border-color: var(--primary); }
  .footer-col h4 { font-size: 0.95rem; font-weight: 700; color: #fff; margin-bottom: 16px; text-transform: uppercase; letter-spacing: .05em; }
  .footer-col a { display: block; font-size: 0.9rem; color: var(--text-muted); padding: 5px 0; transition: color .15s; }
  .footer-col a:hover { color: var(--accent); }
  .footer-bottom { border-top: 1px solid var(--border); padding-top: 24px; display: flex; justify-content: space-between; align-items: center; flex-wrap: wrap; gap: 8px; }
  .footer-bottom p { font-size: 0.9rem; color: var(--text-muted); }

  /* ── Floating Side Contact ── */
  .float-side {
    position: fixed;
    right: 0;
    top: 50%;
    transform: translateY(-50%);
    display: flex;
    flex-direction: column;
    gap: 6px;
    z-index: 998;
  }
  .float-side-btn {
    display: flex;
    align-items: center;
    gap: 10px;
    padding: 14px 18px 14px 16px;
    border-radius: 12px 0 0 12px;
    font-weight: 700;
    color: #fff;
    box-shadow: -4px 4px 20px rgba(0,0,0,0.5);
    transition: all .3s ease;
    white-space: nowrap;
    text-decoration: none;
    min-width: 148px;
    border: none;
    cursor: pointer;
  }
  .float-side-btn:hover {
    transform: translateX(-6px);
    box-shadow: -10px 4px 28px rgba(0,0,0,0.6);
    min-width: 160px;
  }
  .float-tg { background: linear-gradient(135deg, #26a5e4, #1b8fcf); }
  .float-kefu { background: linear-gradient(135deg, #12b7f5, #0a9fd9); }
  .float-side-icon { font-size: 1.5rem; flex-shrink: 0; }
  .float-side-text { display: flex; flex-direction: column; line-height: 1.3; }
  .float-side-text strong { font-size: 0.95rem; }
  .float-side-text span { font-size: 0.78rem; opacity: 0.85; }

  /* ── Responsive ── */
  @media (max-width: 900px) {
    .navbar { padding: 0 20px; }
    .nav-links { display: none; }
    .about-grid { grid-template-columns: 1fr; }
    .faq-grid { grid-template-columns: 1fr; }
    .footer-grid { grid-template-columns: 1fr 1fr; }
    .float-side-btn { min-width: 52px; padding: 14px 14px; }
    .float-side-btn:hover { min-width: 52px; transform: translateX(0); }
    .float-side-text { display: none; }
    .float-side-icon { font-size: 1.6rem; }
    .float-side { gap: 8px; }
  }
  @media (max-width: 600px) {
    .footer-grid { grid-template-columns: 1fr; }
    .hero-stats { gap: 24px; }
    .pricing-tabs { gap: 6px; }
    .tab-btn { padding: 9px 16px; font-size: 0.9rem; }
  }
/* piaohost-sidebar-fix */
.float-side,.floating-side{position:fixed;right:0;top:50%;transform:translateY(-50%);display:flex;flex-direction:column;gap:8px;z-index:998}
.float-side-btn,.fsb{width:166px;min-width:166px;min-height:58px;display:flex;align-items:center;gap:10px;padding:10px 14px;border-radius:14px 0 0 14px;font-weight:700;color:#fff;text-decoration:none;box-shadow:-6px 8px 24px rgba(0,0,0,.36);transition:all .25s ease;white-space:nowrap;overflow:hidden}
.float-side-btn:hover,.fsb:hover{transform:translateX(-8px);box-shadow:-10px 10px 30px rgba(0,0,0,.45)}
.float-tg,.fsb-tg{background:linear-gradient(135deg,#27a7e7,#147bd1)}
.float-kefu,.fsb-kefu{background:linear-gradient(135deg,#2563eb,#0ea5e9)}
.float-side-icon,.fsb-icon{width:34px;height:34px;border-radius:50%;background:rgba(255,255,255,.18);display:inline-flex;align-items:center;justify-content:center;flex:0 0 34px;font-size:14px;font-weight:800;color:#fff}
.float-side-text,.fsb-text{display:flex;flex-direction:column;align-items:flex-start;justify-content:center;line-height:1.25;min-width:0}
.float-side-text strong,.fsb-text strong{display:block;font-size:14px;color:#fff;letter-spacing:0}
.float-side-text span,.fsb-text span{display:block;font-size:12px;color:rgba(255,255,255,.86)}
@media(max-width:600px){.float-side-btn,.fsb{width:58px;min-width:58px;padding:12px}.float-side-text,.fsb-text{display:none}}