:root {
    --bg-deep: #070A14;
    --bg-card: rgba(255,255,255,0.06);
    --bg-card-hover: rgba(255,255,255,0.10);
    --glass-border: rgba(255,255,255,0.10);
    --primary: #7C5CFF;
    --accent: #69E7FF;
    --success: #62FAD3;
    --text-primary: #F7FAFF;
    --text-secondary: #9AA7C7;
    --text-muted: #6B7A99;
    --gradient-aurora: linear-gradient(135deg, #7C5CFF 0%, #69E7FF 50%, #62FAD3 100%);
    --gradient-bg: radial-gradient(ellipse at 20% 0%, rgba(124,92,255,0.15) 0%, transparent 50%),
                   radial-gradient(ellipse at 80% 20%, rgba(105,231,255,0.08) 0%, transparent 50%),
                   radial-gradient(ellipse at 50% 80%, rgba(98,250,211,0.06) 0%, transparent 50%);
    --font-stack: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Microsoft YaHei", "Helvetica Neue", Arial, sans-serif;
    --radius-sm: 8px;
    --radius-md: 16px;
    --radius-lg: 24px;
    --shadow-card: 0 8px 32px rgba(0,0,0,0.3);
    --shadow-glow: 0 0 40px rgba(124,92,255,0.15);
  }

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

  /* 关键修复：让 hidden 属性始终生效（否则被下方 display:flex 覆盖，弹窗关不掉） */
  [hidden] { display: none !important; }

  html { scroll-behavior: smooth; }

  body {
    font-family: var(--font-stack);
    background: var(--bg-deep);
    color: var(--text-primary);
    line-height: 1.6;
    min-height: 100vh;
    overflow-x: hidden;
  }

  body::before {
    content: '';
    position: fixed;
    top: 0; left: 0; right: 0; bottom: 0;
    background: var(--gradient-bg);
    pointer-events: none;
    z-index: 0;
  }

  .page-wrap { position: relative; z-index: 1; }

  /* ===== NAV ===== */
  .top-nav {
    position: sticky;
    top: 0;
    z-index: 100;
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    background: rgba(7,10,20,0.7);
    border-bottom: 1px solid var(--glass-border);
    padding: 0 24px;
  }
  .nav-inner {
    max-width: 1200px;
    margin: 0 auto;
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 60px;
  }
  .nav-brand {
    font-size: 16px;
    font-weight: 700;
    color: var(--text-primary);
    letter-spacing: 0.5px;
  }
  .nav-brand span {
    background: var(--gradient-aurora);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
  }
  .nav-links { display: flex; gap: 24px; list-style: none; }
  .nav-links a {
    color: var(--text-secondary);
    text-decoration: none;
    font-size: 14px;
    transition: color 0.2s;
  }
  .nav-links a:hover, .nav-links a:focus { color: var(--accent); }

  /* ===== HERO ===== */
  .hero {
    max-width: 1200px;
    margin: 0 auto;
    padding: 80px 24px 60px;
    text-align: center;
  }
  .hero-badge {
    display: inline-block;
    padding: 6px 16px;
    border-radius: 20px;
    background: rgba(124,92,255,0.15);
    border: 1px solid rgba(124,92,255,0.3);
    color: var(--accent);
    font-size: 13px;
    font-weight: 500;
    margin-bottom: 24px;
    letter-spacing: 1px;
  }
  .hero h1 {
    font-size: clamp(32px, 5vw, 56px);
    font-weight: 800;
    line-height: 1.2;
    margin-bottom: 20px;
    background: linear-gradient(135deg, #F7FAFF 0%, #9AA7C7 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
  }
  .hero-sub {
    font-size: clamp(16px, 2vw, 20px);
    color: var(--text-secondary);
    max-width: 640px;
    margin: 0 auto 40px;
    line-height: 1.7;
  }
  .hero-stats {
    display: flex;
    justify-content: center;
    gap: 48px;
    flex-wrap: wrap;
  }
  .hero-stat { text-align: center; }
  .hero-stat-value {
    font-size: 36px;
    font-weight: 800;
    background: var(--gradient-aurora);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
  }
  .hero-stat-label {
    font-size: 13px;
    color: var(--text-muted);
    margin-top: 4px;
    letter-spacing: 0.5px;
  }

  /* ===== SECTION ===== */
  .section {
    max-width: 1200px;
    margin: 0 auto;
    padding: 60px 24px;
  }
  .section-header {
    text-align: center;
    margin-bottom: 48px;
  }
  .section-header h2 {
    font-size: clamp(24px, 3vw, 36px);
    font-weight: 700;
    margin-bottom: 12px;
    color: var(--text-primary);
  }
  .section-header p {
    color: var(--text-secondary);
    font-size: 16px;
    max-width: 520px;
    margin: 0 auto;
  }
  .section-divider {
    width: 60px;
    height: 3px;
    background: var(--gradient-aurora);
    border-radius: 2px;
    margin: 16px auto 0;
  }

  /* ===== PRODUCT GRID ===== */
  .product-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
    gap: 24px;
  }
  .product-card {
    background: var(--bg-card);
    border: 1px solid var(--glass-border);
    border-radius: var(--radius-lg);
    padding: 32px 28px;
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    transition: background 0.3s, transform 0.3s, box-shadow 0.3s;
    display: flex;
    flex-direction: column;
    position: relative;
    overflow: hidden;
  }
  .product-card:hover {
    background: var(--bg-card-hover);
    transform: translateY(-4px);
    box-shadow: var(--shadow-glow);
  }
  .product-card::before {
    content: '';
    position: absolute;
    top: 0; left: 0; right: 0;
    height: 3px;
    background: var(--gradient-aurora);
    opacity: 0;
    transition: opacity 0.3s;
  }
  .product-card:hover::before { opacity: 1; }
  .product-icon {
    width: 80px;
    height: 80px;
    margin-bottom: 20px;
    background: rgba(124,92,255,0.1);
    border-radius: var(--radius-md);
    display: flex;
    align-items: center;
    justify-content: center;
  }
  .product-icon svg { width: 48px; height: 48px; }
  .product-name { font-size: 22px; font-weight: 700; margin-bottom: 6px; color: var(--text-primary); }
  .product-model { font-size: 13px; color: var(--text-muted); margin-bottom: 16px; letter-spacing: 0.5px; }
  .product-specs {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 12px;
    margin-bottom: 20px;
    flex-grow: 1;
  }
  .spec-item { display: flex; flex-direction: column; gap: 2px; }
  .spec-label { font-size: 11px; color: var(--text-muted); text-transform: uppercase; letter-spacing: 0.8px; }
  .spec-value { font-size: 15px; font-weight: 600; color: var(--text-primary); }
  .product-features { display: flex; flex-wrap: wrap; gap: 6px; margin-bottom: 20px; }
  .feature-tag {
    padding: 4px 10px;
    border-radius: 12px;
    background: rgba(105,231,255,0.08);
    border: 1px solid rgba(105,231,255,0.15);
    font-size: 12px;
    color: var(--accent);
    white-space: nowrap;
  }
  .product-price {
    display: flex;
    align-items: baseline;
    gap: 4px;
    padding-top: 16px;
    border-top: 1px solid var(--glass-border);
  }
  .price-currency { font-size: 16px; font-weight: 600; color: var(--success); }
  .price-amount { font-size: 32px; font-weight: 800; color: var(--success); line-height: 1; }
  .price-unit { font-size: 13px; color: var(--text-muted); margin-left: 4px; }

  /* ===== COMPARISON TABLE ===== */
  .table-wrap {
    overflow-x: auto;
    border-radius: var(--radius-lg);
    border: 1px solid var(--glass-border);
    background: var(--bg-card);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
  }
  .compare-table { width: 100%; border-collapse: collapse; min-width: 700px; font-size: 14px; }
  .compare-table thead th {
    padding: 16px 18px; text-align: left; font-weight: 600; font-size: 12px;
    text-transform: uppercase; letter-spacing: 0.8px; color: var(--text-muted);
    border-bottom: 1px solid var(--glass-border); background: rgba(255,255,255,0.02); white-space: nowrap;
  }
  .compare-table tbody td { padding: 14px 18px; border-bottom: 1px solid rgba(255,255,255,0.04); color: var(--text-primary); white-space: nowrap; }
  .compare-table tbody tr:last-child td { border-bottom: none; }
  .compare-table tbody tr:hover { background: rgba(255,255,255,0.03); }
  .compare-table .model-name { font-weight: 600; color: var(--accent); }
  .compare-table .price-cell { font-weight: 700; color: var(--success); font-size: 16px; }

  /* ===== BUSINESS INFO ===== */
  .biz-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(280px, 1fr)); gap: 20px; }
  .biz-card {
    background: var(--bg-card); border: 1px solid var(--glass-border); border-radius: var(--radius-md);
    padding: 24px; backdrop-filter: blur(12px); -webkit-backdrop-filter: blur(12px);
  }
  .biz-card h3 { font-size: 15px; font-weight: 600; color: var(--accent); margin-bottom: 8px; display: flex; align-items: center; gap: 8px; }
  .biz-card p { font-size: 14px; color: var(--text-secondary); line-height: 1.6; }

  /* ===== CTA ===== */
  .cta-section { text-align: center; padding: 80px 24px; max-width: 1200px; margin: 0 auto; }
  .cta-section h2 { font-size: clamp(24px, 3vw, 36px); font-weight: 700; margin-bottom: 16px; }
  .cta-section p { color: var(--text-secondary); font-size: 16px; margin-bottom: 32px; max-width: 480px; margin-left: auto; margin-right: auto; }
  .cta-btn {
    display: inline-block; padding: 14px 40px; background: var(--gradient-aurora); color: #070A14;
    font-size: 16px; font-weight: 700; border-radius: 12px; text-decoration: none;
    transition: transform 0.2s, box-shadow 0.2s; border: none; cursor: pointer;
  }
  .cta-btn:hover { transform: translateY(-2px); box-shadow: 0 8px 30px rgba(124,92,255,0.3); }

  /* ===== FOOTER ===== */
  .page-footer { border-top: 1px solid var(--glass-border); padding: 32px 24px; text-align: center; max-width: 1200px; margin: 0 auto; }
  .footer-company { font-size: 14px; color: var(--text-muted); margin-bottom: 8px; }
  .footer-note { font-size: 12px; color: var(--text-muted); }

  /* ===== ACCESSIBILITY ===== */
  a:focus-visible, button:focus-visible, .cta-btn:focus-visible { outline: 2px solid var(--accent); outline-offset: 2px; }
  @media (prefers-reduced-motion: reduce) {
    *, *::before, *::after { animation-duration: 0.01ms !important; transition-duration: 0.01ms !important; scroll-behavior: auto !important; }
  }

  /* ===== RESPONSIVE ===== */
  @media (max-width: 768px) {
    .nav-links { display: none; }
    .hero { padding: 48px 20px 40px; }
    .hero-stats { gap: 32px; }
    .hero-stat-value { font-size: 28px; }
    .section { padding: 40px 20px; }
    .product-grid { grid-template-columns: 1fr; }
    .product-card { padding: 24px 20px; }
    .biz-grid { grid-template-columns: 1fr; }
    .cta-section { padding: 48px 20px; }
  }
  @media (max-width: 480px) {
    .hero-stats { flex-direction: column; gap: 20px; }
    .product-specs { grid-template-columns: 1fr; }
  }

  /* ============================================================
     AI 咨询聊天组件
     ============================================================ */
  .chat-fab {
    position: fixed;
    right: 24px;
    bottom: 24px;
    width: 60px;
    height: 60px;
    border-radius: 50%;
    border: none;
    cursor: pointer;
    background: var(--gradient-aurora);
    color: #070A14;
    box-shadow: 0 8px 30px rgba(124,92,255,0.45);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 1000;
    transition: transform 0.2s, box-shadow 0.2s;
  }
  .chat-fab:hover { transform: translateY(-3px) scale(1.05); box-shadow: 0 12px 40px rgba(124,92,255,0.6); }
  .chat-fab svg { width: 30px; height: 30px; }

  .chat-panel {
    position: fixed;
    right: 24px;
    bottom: 96px;
    width: 380px;
    max-width: calc(100vw - 32px);
    height: 560px;
    max-height: calc(100vh - 130px);
    background: rgba(11,15,28,0.92);
    border: 1px solid var(--glass-border);
    border-radius: var(--radius-md);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    box-shadow: 0 20px 60px rgba(0,0,0,0.5);
    display: flex;
    flex-direction: column;
    overflow: hidden;
    z-index: 1000;
    animation: chatPop 0.18s ease-out;
  }
  @keyframes chatPop { from { opacity: 0; transform: translateY(12px) scale(0.98); } to { opacity: 1; transform: none; } }

  .chat-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 14px 16px;
    border-bottom: 1px solid var(--glass-border);
    background: rgba(124,92,255,0.08);
  }
  .chat-title { font-size: 15px; font-weight: 700; display: flex; align-items: center; gap: 8px; }
  .chat-title .dot { width: 8px; height: 8px; border-radius: 50%; background: var(--success); box-shadow: 0 0 8px var(--success); }
  .chat-actions { display: flex; gap: 4px; }
  .chat-actions button {
    background: transparent; border: none; color: var(--text-secondary); cursor: pointer;
    width: 30px; height: 30px; border-radius: 8px; font-size: 15px; display: flex; align-items: center; justify-content: center;
    transition: background 0.2s, color 0.2s;
  }
  .chat-actions button:hover { background: rgba(255,255,255,0.08); color: var(--text-primary); }

  .chat-messages {
    flex: 1;
    overflow-y: auto;
    padding: 16px;
    display: flex;
    flex-direction: column;
    gap: 12px;
  }
  .chat-messages::-webkit-scrollbar { width: 6px; }
  .chat-messages::-webkit-scrollbar-thumb { background: rgba(255,255,255,0.15); border-radius: 3px; }

  .msg { display: flex; gap: 8px; max-width: 92%; }
  .msg.user { align-self: flex-end; flex-direction: row-reverse; }
  .msg-avatar {
    width: 30px; height: 30px; border-radius: 50%; flex-shrink: 0;
    display: flex; align-items: center; justify-content: center; font-size: 14px;
  }
  .msg.bot .msg-avatar { background: var(--gradient-aurora); color: #070A14; font-weight: 700; }
  .msg.user .msg-avatar { background: rgba(255,255,255,0.1); color: var(--text-primary); }
  .msg-bubble {
    padding: 10px 14px; border-radius: 14px; font-size: 14px; line-height: 1.6;
    white-space: pre-wrap; word-break: break-word;
  }
  .msg.bot .msg-bubble { background: rgba(255,255,255,0.07); border: 1px solid var(--glass-border); border-top-left-radius: 4px; }
  .msg.user .msg-bubble { background: var(--gradient-aurora); color: #070A14; font-weight: 500; border-top-right-radius: 4px; }
  .msg-bubble.typing::after { content: '▋'; animation: blink 1s step-start infinite; }
  @keyframes blink { 50% { opacity: 0; } }

  .chat-suggestions { display: flex; flex-wrap: wrap; gap: 8px; padding: 0 16px 8px; }
  .suggestion-chip {
    padding: 6px 12px; border-radius: 14px; font-size: 12.5px; cursor: pointer;
    background: rgba(105,231,255,0.08); border: 1px solid rgba(105,231,255,0.2); color: var(--accent);
    transition: background 0.2s;
  }
  .suggestion-chip:hover { background: rgba(105,231,255,0.18); }

  .chat-input-row { display: flex; gap: 8px; padding: 12px 16px; border-top: 1px solid var(--glass-border); }
  .chat-input-row input {
    flex: 1; background: rgba(255,255,255,0.06); border: 1px solid var(--glass-border); border-radius: 12px;
    padding: 10px 14px; color: var(--text-primary); font-size: 14px; font-family: var(--font-stack); outline: none;
  }
  .chat-input-row input:focus { border-color: var(--accent); }
  .chat-input-row input::placeholder { color: var(--text-muted); }
  .chat-send {
    background: var(--gradient-aurora); color: #070A14; border: none; border-radius: 12px; padding: 0 18px;
    font-weight: 700; cursor: pointer; font-size: 14px; transition: transform 0.2s;
  }
  .chat-send:hover { transform: translateY(-1px); }
  .chat-send:disabled { opacity: 0.5; cursor: not-allowed; transform: none; }

  /* 设置面板 */
  .chat-settings {
    position: fixed; right: 24px; bottom: 96px; width: 380px; max-width: calc(100vw - 32px);
    background: rgba(11,15,28,0.96); border: 1px solid var(--glass-border); border-radius: var(--radius-md);
    backdrop-filter: blur(20px); -webkit-backdrop-filter: blur(20px); box-shadow: 0 20px 60px rgba(0,0,0,0.5);
    padding: 18px; z-index: 1001; display: flex; flex-direction: column; gap: 12px;
  }
  .chat-settings h4 { font-size: 15px; font-weight: 700; margin-bottom: 2px; }
  .chat-settings .hint { font-size: 12px; color: var(--text-muted); line-height: 1.5; }
  .chat-settings label { font-size: 12.5px; color: var(--text-secondary); display: flex; flex-direction: column; gap: 5px; }
  .chat-settings input, .chat-settings select {
    background: rgba(255,255,255,0.06); border: 1px solid var(--glass-border); border-radius: 8px;
    padding: 9px 12px; color: var(--text-primary); font-size: 13px; font-family: var(--font-stack); outline: none;
  }
  .chat-settings input:focus, .chat-settings select:focus { border-color: var(--accent); }
  .chat-settings .settings-actions { display: flex; gap: 8px; margin-top: 4px; }
  .chat-settings .btn-primary { flex: 1; background: var(--gradient-aurora); color: #070A14; border: none; border-radius: 10px; padding: 10px; font-weight: 700; cursor: pointer; font-size: 13px; }
  .chat-settings .btn-ghost { background: transparent; border: 1px solid var(--glass-border); color: var(--text-secondary); border-radius: 10px; padding: 10px; cursor: pointer; font-size: 13px; }

  .config-note {
    font-size: 12px; color: var(--text-muted); background: rgba(124,92,255,0.08);
    border: 1px solid rgba(124,92,255,0.2); border-radius: 10px; padding: 8px 10px; line-height: 1.5;
  }