/* roulang page: index */
/* ----- CSS 自定义属性 (设计变量) ----- */
    :root {
      --primary-red: #D32F2F;
      --primary-dark: #B71C1C;
      --deep-charcoal: #1B1B1B;
      --electric-yellow: #FFC107;
      --yellow-light: #FFD54F;
      --bg-light: #FAFAFA;
      --bg-gray: #F5F5F5;
      --white: #FFFFFF;
      --card-bg: #FFFFFF;
      --dark-card-bg: #2A2A2A;
      --text-body: #555555;
      --text-muted: #888888;
      --border-light: #EEEEEE;
      --radius-card: 16px;
      --radius-btn: 50px;
      --radius-badge: 8px;
      --shadow-card: 0 4px 20px rgba(0,0,0,0.06);
      --shadow-hover: 0 8px 30px rgba(0,0,0,0.12);
      --font-sans: "PingFang SC", "Microsoft YaHei", "Helvetica Neue", sans-serif;
      --transition-base: 0.25s ease;
      --max-width: 1200px;
      --header-height: 72px;
    }

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

    html {
      scroll-behavior: smooth;
    }

    body {
      font-family: var(--font-sans);
      font-size: 16px;
      line-height: 1.7;
      font-weight: 400;
      color: var(--text-body);
      background-color: var(--bg-light);
      -webkit-font-smoothing: antialiased;
      overflow-x: hidden;
    }

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

    a {
      text-decoration: none;
      color: inherit;
      transition: var(--transition-base);
    }

    button, .btn {
      cursor: pointer;
      font-family: inherit;
      border: none;
      background: none;
      display: inline-flex;
      align-items: center;
      justify-content: center;
      transition: var(--transition-base);
    }

    ul {
      list-style: none;
    }

    /* ----- 容器 & 通用布局 ----- */
    .container {
      max-width: var(--max-width);
      margin: 0 auto;
      padding: 0 24px;
    }

    section {
      padding: 100px 0;
    }

    @media (max-width: 768px) {
      section {
        padding: 64px 0;
      }
    }

    /* 通用标题 */
    .section-title {
      font-size: 32px;
      line-height: 1.3;
      font-weight: 700;
      color: var(--deep-charcoal);
      margin-bottom: 16px;
    }

    .section-subtitle {
      font-size: 18px;
      color: var(--text-body);
      max-width: 600px;
      margin-bottom: 48px;
    }

    /* ----- 导航 Header ----- */
    #header {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      height: var(--header-height);
      background: var(--white);
      border-bottom: 1px solid var(--border-light);
      z-index: 100;
      display: flex;
      align-items: center;
      transition: box-shadow 0.3s ease;
    }

    #header.scrolled {
      box-shadow: 0 4px 12px rgba(0,0,0,0.05);
    }

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

    .logo {
      font-size: 24px;
      font-weight: 800;
      color: var(--primary-red);
      letter-spacing: 1px;
      display: flex;
      align-items: center;
      gap: 8px;
    }

    .logo-icon {
      width: 28px;
      height: 28px;
      background: var(--primary-red);
      mask: url('data:image/svg+xml;utf8,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24" fill="white"><path d="M12 2L15 9H22L16 14L18 21L12 16.5L6 21L8 14L2 9H9L12 2Z"/></svg>') center/cover;
      background-color: var(--primary-red);
    }

    .nav-links {
      display: flex;
      gap: 32px;
      align-items: center;
    }

    .nav-links a {
      font-size: 16px;
      font-weight: 500;
      color: var(--deep-charcoal);
      position: relative;
      padding: 4px 0;
    }

    .nav-links a::after {
      content: '';
      position: absolute;
      bottom: -2px;
      left: 0;
      width: 0;
      height: 2px;
      background: var(--primary-red);
      transition: width 0.2s ease;
    }

    .nav-links a:hover::after,
    .nav-links a.active::after {
      width: 100%;
    }

    .btn-primary {
      background: var(--primary-red);
      color: var(--white);
      border-radius: var(--radius-btn);
      padding: 12px 32px;
      font-weight: 600;
      font-size: 16px;
      box-shadow: 0 4px 12px rgba(211,47,47,0.25);
    }

    .btn-primary:hover {
      background: var(--primary-dark);
      box-shadow: 0 0 12px rgba(211,47,47,0.4);
    }

    .hamburger {
      display: none;
      flex-direction: column;
      gap: 5px;
      cursor: pointer;
    }

    .hamburger span {
      width: 24px;
      height: 2px;
      background: var(--deep-charcoal);
      border-radius: 2px;
      transition: 0.3s;
    }

    @media (max-width: 768px) {
      .nav-links {
        position: fixed;
        top: 0;
        right: -100%;
        width: 70%;
        height: 100vh;
        background: var(--white);
        flex-direction: column;
        justify-content: center;
        gap: 32px;
        box-shadow: -4px 0 20px rgba(0,0,0,0.1);
        transition: right 0.3s ease;
        z-index: 99;
      }
      .nav-links.active {
        right: 0;
      }
      .hamburger {
        display: flex;
        z-index: 101;
      }
      .nav-container .btn-primary {
        display: none;
      }
    }

    /* ----- Hero 首屏 ----- */
    #hero {
      background: linear-gradient(135deg, #D32F2F 0%, #1B1B1B 100%);
      position: relative;
      overflow: hidden;
      padding: 140px 0 100px;
      color: var(--white);
    }

    #hero::before {
      content: "";
      position: absolute;
      top: 0;
      left: 0;
      width: 100%;
      height: 100%;
      background-image: url('data:image/svg+xml;utf8,<svg xmlns="http://www.w3.org/2000/svg" width="100" height="100" viewBox="0 0 100 100"><filter id="noise"><feTurbulence type="fractalNoise" baseFrequency="0.8" numOctaves="3" stitchTiles="stitch"/></filter><rect width="100" height="100" filter="url(/%23noise)" opacity="0.15"/></svg>');
      pointer-events: none;
    }

    .hero-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 48px;
      align-items: center;
      position: relative;
      z-index: 2;
    }

    .hero-content h1 {
      font-size: 42px;
      line-height: 1.2;
      font-weight: 800;
      margin-bottom: 20px;
    }

    .hero-subtitle {
      font-size: 18px;
      opacity: 0.8;
      margin-bottom: 32px;
    }

    .hero-buttons {
      display: flex;
      gap: 16px;
      flex-wrap: wrap;
      margin-bottom: 40px;
    }

    .btn-secondary {
      background: transparent;
      border: 2px solid var(--white);
      color: var(--white);
      border-radius: var(--radius-btn);
      padding: 12px 32px;
      font-weight: 600;
    }

    .btn-secondary:hover {
      background: var(--white);
      color: var(--primary-red);
    }

    .hero-stats {
      display: flex;
      gap: 24px;
      flex-wrap: wrap;
    }

    .badge-stat {
      background: rgba(255,255,255,0.15);
      backdrop-filter: blur(10px);
      border-radius: var(--radius-badge);
      padding: 8px 20px;
      font-weight: 700;
      display: flex;
      align-items: center;
      gap: 6px;
      font-size: 15px;
      color: var(--electric-yellow);
    }

    .hero-image img {
      border-radius: 24px;
      box-shadow: 0 20px 40px rgba(0,0,0,0.3);
    }

    @media (max-width: 768px) {
      .hero-grid {
        grid-template-columns: 1fr;
      }
      .hero-image {
        order: -1;
      }
      .hero-content h1 {
        font-size: 32px;
      }
    }

    /* ----- 痛点区块 ----- */
    #pain-points {
      background: var(--bg-gray);
    }
    .pain-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 48px;
      align-items: center;
    }
    .pain-list {
      display: flex;
      flex-direction: column;
      gap: 32px;
    }
    .pain-item {
      display: flex;
      gap: 16px;
      font-size: 18px;
      font-weight: 500;
      color: var(--deep-charcoal);
    }
    .pain-icon {
      color: var(--primary-red);
      font-size: 24px;
      flex-shrink: 0;
    }
    @media (max-width: 768px) {
      .pain-grid {
        grid-template-columns: 1fr;
      }
    }

    /* ----- 解决方案卡片 ----- */
    .solution-cards {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
    }
    .card {
      background: var(--card-bg);
      border-radius: var(--radius-card);
      padding: 32px;
      box-shadow: var(--shadow-card);
      transition: var(--transition-base);
      position: relative;
    }
    .card:hover {
      transform: translateY(-4px);
      box-shadow: var(--shadow-hover);
    }
    .card-img {
      width: 64px;
      height: 64px;
      border-radius: 12px;
      margin-bottom: 20px;
      object-fit: cover;
    }
    .card h3 {
      font-size: 20px;
      font-weight: 600;
      color: var(--deep-charcoal);
      margin-bottom: 12px;
    }
    .card p {
      color: var(--text-body);
      margin-bottom: 16px;
    }
    .card-link {
      color: var(--primary-red);
      font-weight: 600;
    }
    .badge-float {
      position: absolute;
      top: 16px;
      right: 16px;
      background: var(--electric-yellow);
      color: var(--deep-charcoal);
      font-weight: 700;
      padding: 6px 14px;
      border-radius: 20px;
      font-size: 14px;
    }
    @media (max-width: 1024px) {
      .solution-cards {
        grid-template-columns: repeat(2, 1fr);
      }
    }
    @media (max-width: 768px) {
      .solution-cards {
        grid-template-columns: 1fr;
      }
    }

    /* ----- 成果展示 ----- */
    #results {
      background: var(--deep-charcoal);
      color: var(--white);
    }
    .results-stats {
      display: flex;
      justify-content: center;
      gap: 48px;
      flex-wrap: wrap;
      margin-bottom: 48px;
    }
    .stat-item {
      text-align: center;
    }
    .stat-number {
      font-size: 48px;
      font-weight: 800;
      color: var(--electric-yellow);
    }
    .compare-bar {
      display: flex;
      align-items: center;
      gap: 24px;
      background: rgba(255,255,255,0.1);
      border-radius: 16px;
      padding: 24px;
    }

    /* ----- 证言网格 ----- */
    .testimonial-grid {
      display: grid;
      grid-template-columns: repeat(2, 1fr);
      gap: 24px;
    }
    .testimonial-card {
      background: var(--bg-gray);
      border-radius: var(--radius-card);
      padding: 24px;
      display: flex;
      gap: 16px;
      border-left: 4px solid var(--primary-red);
    }
    .avatar {
      width: 48px;
      height: 48px;
      border-radius: 50%;
      background: #ccc;
      flex-shrink: 0;
    }
    @media (max-width: 768px) {
      .testimonial-grid {
        grid-template-columns: 1fr;
      }
    }

    /* ----- FAQ 手风琴 ----- */
    .faq-item {
      border-bottom: 1px solid var(--border-light);
    }
    .faq-question {
      width: 100%;
      padding: 20px 0;
      display: flex;
      align-items: center;
      gap: 12px;
      font-weight: 600;
      font-size: 18px;
      text-align: left;
      background: transparent;
      border: none;
      cursor: pointer;
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.3s ease;
      background: #f9f9f9;
      padding: 0 16px;
    }
    .faq-item.active .faq-answer {
      max-height: 200px;
      padding: 16px;
    }

    /* ----- CTA 区块 ----- */
    #cta {
      background: linear-gradient(135deg, #D32F2F, #1B1B1B);
      text-align: center;
      color: white;
    }
    .btn-cta {
      background: var(--electric-yellow);
      color: var(--deep-charcoal);
      font-size: 18px;
      padding: 18px 48px;
      border-radius: var(--radius-btn);
      font-weight: 700;
    }
    .btn-cta:hover {
      background: var(--yellow-light);
    }

    /* ----- Footer ----- */
    #footer {
      background: var(--deep-charcoal);
      color: #ccc;
      padding: 48px 0 24px;
    }
    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1fr;
      gap: 32px;
    }
    @media (max-width: 768px) {
      .footer-grid {
        grid-template-columns: 1fr;
      }
    }