/* roulang page: index */
/* ----- CSS 变量与全局重置 ----- */
    :root {
      --bg-deep: #0B0E2D;
      --bg-card: rgba(15, 20, 45, 0.6);
      --bg-footer: #080B20;
      --primary-cyan: #00E5FF;
      --primary-cyan-dark: #00B8D4;
      --accent-orange: #FF6D00;
      --text-white: rgba(255, 255, 255, 0.92);
      --text-light: rgba(255, 255, 255, 0.8);
      --text-muted: rgba(255, 255, 255, 0.5);
      --border-glow: rgba(0, 229, 255, 0.18);
      --radius-card: 16px;
      --radius-btn: 8px;
      --radius-pill: 24px;
      --shadow-card: 0 8px 32px rgba(0, 0, 0, 0.45), 0 0 1px rgba(0, 229, 255, 0.25);
      --font-sans: "PingFang SC", "Microsoft YaHei", "Hiragino Sans GB", system-ui, -apple-system, sans-serif;
      --font-number: "Inter", "SF Pro Display", "PingFang SC", "Microsoft YaHei", sans-serif;
      --max-width: 1200px;
      --nav-height: 72px;
    }

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

    html {
      scroll-behavior: smooth;
      font-size: 16px;
    }

    body {
      font-family: var(--font-sans);
      background-color: var(--bg-deep);
      color: var(--text-light);
      line-height: 1.7;
      -webkit-font-smoothing: antialiased;
      -moz-osx-font-smoothing: grayscale;
      background-image: 
        linear-gradient(rgba(0, 229, 255, 0.03) 1px, transparent 1px),
        linear-gradient(90deg, rgba(0, 229, 255, 0.03) 1px, transparent 1px);
      background-size: 60px 60px;
      background-position: center center;
    }

    a {
      text-decoration: none;
      color: inherit;
      transition: color 0.2s ease, opacity 0.2s ease;
    }

    img {
      max-width: 100%;
      height: auto;
      display: block;
    }

    button, .btn {
      cursor: pointer;
      font-family: inherit;
      border: none;
      background: none;
      transition: all 0.25s ease;
    }

    /* ----- 容器与布局工具 ----- */
    .container {
      max-width: var(--max-width);
      margin: 0 auto;
      padding: 0 20px;
    }

    section {
      padding: 100px 0;
    }

    @media (max-width: 768px) {
      section {
        padding: 60px 0;
      }
    }

    /* ----- 导航 (桌面端固定玻璃拟态) ----- */
    .site-header {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      z-index: 1000;
      height: var(--nav-height);
      display: flex;
      align-items: center;
      transition: background 0.3s ease, backdrop-filter 0.3s ease;
      background: transparent;
      backdrop-filter: blur(0px);
    }

    .site-header.scrolled {
      background: rgba(11, 14, 45, 0.78);
      backdrop-filter: blur(18px);
      box-shadow: 0 4px 20px rgba(0,0,0,0.3);
    }

    .header-inner {
      display: flex;
      align-items: center;
      justify-content: space-between;
      width: 100%;
    }

    .logo {
      font-size: 1.8rem;
      font-weight: 700;
      letter-spacing: 1px;
      color: white;
      display: flex;
      align-items: baseline;
      gap: 4px;
    }
    .logo span {
      color: var(--primary-cyan);
      font-weight: 700;
    }
    .nav-links {
      display: flex;
      align-items: center;
      gap: 32px;
    }
    .nav-links a {
      color: rgba(255,255,255,0.85);
      font-weight: 500;
      font-size: 0.95rem;
      position: relative;
      padding: 6px 0;
    }
    .nav-links a::after {
      content: '';
      position: absolute;
      bottom: 0;
      left: 0;
      width: 0%;
      height: 2px;
      background: var(--primary-cyan);
      transition: width 0.25s ease;
    }
    .nav-links a:hover {
      color: white;
    }
    .nav-links a:hover::after {
      width: 100%;
    }
    .btn-nav-cta {
      background: var(--accent-orange);
      color: white !important;
      padding: 10px 22px !important;
      border-radius: var(--radius-btn);
      font-weight: 600;
      box-shadow: 0 4px 14px rgba(255, 109, 0, 0.3);
    }
    .btn-nav-cta:hover {
      background: #ff7b1c;
      box-shadow: 0 0 20px rgba(255, 109, 0, 0.7);
      transform: scale(1.02);
    }

    .mobile-menu-toggle {
      display: none;
      flex-direction: column;
      gap: 5px;
      background: transparent;
      border: none;
      width: 32px;
      height: 24px;
      cursor: pointer;
    }
    .mobile-menu-toggle span {
      display: block;
      width: 100%;
      height: 2.5px;
      background: white;
      border-radius: 2px;
      transition: 0.2s;
    }

    @media (max-width: 768px) {
      .nav-links {
        display: none;
      }
      .mobile-menu-toggle {
        display: flex;
      }
      .mobile-menu {
        position: fixed;
        top: 0;
        left: 0;
        width: 100%;
        height: 100vh;
        background: rgba(8, 11, 32, 0.95);
        backdrop-filter: blur(25px);
        display: flex;
        flex-direction: column;
        align-items: center;
        justify-content: center;
        gap: 32px;
        z-index: 999;
        transform: translateX(100%);
        transition: transform 0.3s ease;
      }
      .mobile-menu.active {
        transform: translateX(0);
      }
      .mobile-menu a {
        font-size: 1.6rem;
        font-weight: 500;
        color: white;
      }
      .close-menu {
        position: absolute;
        top: 24px;
        right: 24px;
        font-size: 2rem;
        color: white;
        background: none;
        border: none;
      }
    }

    /* ----- 按钮体系 ----- */
    .btn-primary {
      background: var(--accent-orange);
      color: white;
      font-weight: 600;
      padding: 14px 32px;
      border-radius: var(--radius-btn);
      font-size: 1rem;
      display: inline-block;
      box-shadow: 0 4px 16px rgba(255, 109, 0, 0.3);
      letter-spacing: 0.3px;
    }
    .btn-primary:hover {
      transform: scale(1.04);
      box-shadow: 0 0 28px rgba(255, 109, 0, 0.7);
    }
    .btn-outline {
      background: transparent;
      border: 1.5px solid var(--primary-cyan);
      color: var(--primary-cyan);
      font-weight: 600;
      padding: 14px 32px;
      border-radius: var(--radius-btn);
      font-size: 1rem;
      display: inline-block;
    }
    .btn-outline:hover {
      background: rgba(0, 229, 255, 0.07);
      box-shadow: 0 0 14px rgba(0, 229, 255, 0.4);
    }

    /* ----- Hero 首屏 ----- */
    .hero {
      height: 100vh;
      display: flex;
      align-items: center;
      position: relative;
      overflow: hidden;
    }
    .hero-bg {
      position: absolute;
      inset: 0;
      background: radial-gradient(circle at 30% 40%, rgba(0,229,255,0.12) 0%, transparent 50%);
      z-index: 0;
    }
    .hero-content {
      position: relative;
      z-index: 2;
      max-width: 700px;
    }
    .hero h1 {
      font-size: 3.2rem;
      font-weight: 700;
      line-height: 1.2;
      background: linear-gradient(to right, #00E5FF, #00B8D4);
      -webkit-background-clip: text;
      -webkit-text-fill-color: transparent;
      background-clip: text;
      margin-bottom: 1.2rem;
    }
    .hero-sub {
      font-size: 1.3rem;
      color: rgba(255,255,255,0.7);
      margin-bottom: 2.2rem;
    }
    .hero-buttons {
      display: flex;
      gap: 18px;
      flex-wrap: wrap;
    }

    @media (max-width: 768px) {
      .hero h1 {
        font-size: 2.3rem;
      }
      .hero-sub {
        font-size: 1.1rem;
      }
    }

    /* ----- 玻璃拟态卡片 ----- */
    .glass-card {
      background: var(--bg-card);
      backdrop-filter: blur(18px);
      -webkit-backdrop-filter: blur(18px);
      border: 1px solid var(--border-glow);
      border-radius: var(--radius-card);
      box-shadow: var(--shadow-card);
    }

    /* ----- 痛点区不对称网格 ----- */
    .pain-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr;
      gap: 24px;
    }
    .pain-large {
      border-left: 4px solid var(--primary-cyan);
    }
    @media (max-width: 768px) {
      .pain-grid {
        grid-template-columns: 1fr;
      }
    }

    /* ----- 解决方案交替图文 ----- */
    .solution-row {
      display: flex;
      align-items: center;
      gap: 60px;
      margin-bottom: 80px;
    }
    .solution-row.reverse {
      flex-direction: row-reverse;
    }
    .solution-text {
      flex: 1;
    }
    .solution-img {
      flex: 1;
      background: rgba(0,229,255,0.05);
      border-radius: 12px;
      padding: 16px;
    }

    /* ----- 成果数字 ----- */
    .stats-grid {
      display: flex;
      justify-content: space-around;
      text-align: center;
    }
    .stat-number {
      font-size: 3rem;
      font-weight: 700;
      color: var(--primary-cyan);
      text-shadow: 0 0 22px rgba(0,229,255,0.55);
    }

    /* ----- 证言轮播 ----- */
    .testimonial-carousel {
      display: flex;
      overflow-x: auto;
      gap: 24px;
      padding: 10px 0;
      scroll-snap-type: x mandatory;
    }
    .testimonial-card {
      min-width: 300px;
      scroll-snap-align: start;
    }

    /* ----- FAQ 手风琴 ----- */
    .faq-item {
      border-bottom: 1px solid rgba(255,255,255,0.06);
    }
    .faq-question {
      width: 100%;
      text-align: left;
      padding: 20px 0;
      font-size: 1.1rem;
      font-weight: 600;
      color: white;
      display: flex;
      justify-content: space-between;
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.3s ease;
      color: var(--text-light);
    }

    /* ----- 最终 CTA ----- */
    .cta-final {
      background: linear-gradient(180deg, #0B0E2D 0%, #0A1A3A 100%);
      text-align: center;
    }

    /* ----- 页脚 ----- */
    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1fr;
      gap: 30px;
    }
    @media (max-width: 768px) {
      .footer-grid {
        grid-template-columns: 1fr;
      }
    }