/* roulang page: index */
/* ----- 全局设计变量 ----- */
    :root {
      --primary-black: #0B0C10;
      --accent-red: #E63946;
      --accent-red-dark: #C1121F;
      --gray-light: #F1F2F6;
      --gray-dark: #2B2D31;
      --text-body: #3A3C42;
      --text-heading: #0B0C10;
      --text-light: #FFFFFF;
      --border-light: #E9ECEF;
      --shadow-card: 0 4px 20px rgba(0,0,0,0.04);
      --shadow-hover: 0 12px 32px rgba(0,0,0,0.08);
      --radius-card: 12px;
      --radius-btn: 8px;
      --radius-img: 12px;
      --font-sans: "PingFang SC", "Microsoft YaHei", "Helvetica Neue", Helvetica, Arial, sans-serif;
      --transition-smooth: 0.3s ease;
    }

    /* ----- 全局重置 ----- */
    *, *::before, *::after {
      box-sizing: border-box;
      margin: 0;
      padding: 0;
    }

    html {
      scroll-behavior: smooth;
    }

    body {
      font-family: var(--font-sans);
      background-color: #fff;
      color: var(--text-body);
      line-height: 1.8;
      font-size: 1rem;
      -webkit-font-smoothing: antialiased;
    }

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

    a {
      text-decoration: none;
      color: inherit;
    }

    /* ----- 容器 ----- */
    .container {
      max-width: 1280px;
      margin: 0 auto;
      padding: 0 1.5rem;
    }

    /* ----- 按钮系统 ----- */
    .btn {
      display: inline-block;
      font-weight: 700;
      letter-spacing: 0.05em;
      text-transform: uppercase;
      padding: 1rem 2.5rem;
      border-radius: var(--radius-btn);
      transition: background 0.3s, transform 0.2s, box-shadow 0.3s;
      cursor: pointer;
      border: none;
      text-align: center;
      line-height: 1.2;
    }

    .btn-primary {
      background: var(--accent-red);
      color: white;
      box-shadow: 0 4px 12px rgba(230,57,70,0.2);
    }

    .btn-primary:hover {
      background: var(--accent-red-dark);
      box-shadow: 0 0 20px rgba(230,57,70,0.4);
      transform: translateY(-2px);
    }

    .btn-primary:active {
      transform: scale(0.97);
    }

    .btn-ghost {
      background: transparent;
      border: 2px solid var(--primary-black);
      color: var(--primary-black);
    }

    .btn-ghost:hover {
      background: var(--primary-black);
      color: white;
    }

    /* 链接样式 */
    .text-link {
      color: var(--accent-red);
      font-weight: 600;
      transition: color 0.2s;
    }

    .text-link:hover {
      color: var(--accent-red-dark);
      text-decoration: underline;
    }

    /* ----- 导航 ----- */
    .navbar {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      z-index: 1000;
      background: rgba(11,12,16,0.85);
      backdrop-filter: blur(10px);
      transition: background 0.3s;
      border-bottom: 1px solid rgba(255,255,255,0.05);
    }

    .navbar.scrolled {
      background: rgba(11,12,16,0.98);
    }

    .nav-container {
      display: flex;
      align-items: center;
      justify-content: space-between;
      height: 70px;
    }

    .logo {
      font-size: 1.8rem;
      font-weight: 800;
      letter-spacing: 0.1em;
      color: white;
      white-space: nowrap;
    }
    .logo span {
      color: var(--accent-red);
    }

    .nav-links {
      display: flex;
      gap: 1.8rem;
    }

    .nav-links a {
      color: rgba(255,255,255,0.85);
      font-weight: 500;
      font-size: 0.95rem;
      transition: color 0.2s;
      position: relative;
    }

    .nav-links a:hover {
      color: var(--accent-red);
    }

    /* 汉堡菜单 */
    .menu-toggle {
      display: none;
      flex-direction: column;
      justify-content: space-between;
      width: 28px;
      height: 20px;
      background: transparent;
      border: none;
      cursor: pointer;
    }
    .menu-toggle span {
      width: 100%;
      height: 2px;
      background: white;
      border-radius: 2px;
      transition: 0.3s;
    }

    /* 移动端全屏导航 */
    .mobile-nav {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      height: 100%;
      background: var(--primary-black);
      display: flex;
      flex-direction: column;
      align-items: center;
      justify-content: center;
      gap: 2.5rem;
      transform: translateX(100%);
      transition: transform 0.3s ease;
      z-index: 999;
    }
    .mobile-nav.active {
      transform: translateX(0);
    }
    .mobile-nav a {
      color: white;
      font-size: 1.8rem;
      font-weight: 600;
    }
    .mobile-nav a:hover {
      color: var(--accent-red);
    }

    /* ----- 板块通用 ----- */
    .section {
      padding: 6rem 0;
    }

    .section-dark {
      background-color: var(--gray-light);
    }

    .section-title {
      font-size: clamp(2rem, 5vw, 3.2rem);
      font-weight: 700;
      letter-spacing: -0.01em;
      color: var(--primary-black);
      margin-bottom: 0.5rem;
    }

    .section-subtitle {
      font-size: 1.1rem;
      color: #6B6D76;
      margin-bottom: 3rem;
      max-width: 600px;
    }

    /* ----- Hero ----- */
    .hero {
      background: var(--primary-black);
      color: white;
      min-height: 100vh;
      display: flex;
      align-items: center;
      position: relative;
      overflow: hidden;
      padding-top: 70px;
    }

    .hero-bg-glow {
      position: absolute;
      width: 60vw;
      height: 60vw;
      background: radial-gradient(circle, rgba(230,57,70,0.15) 0%, transparent 70%);
      top: -10%;
      right: -15%;
      animation: slowMove 20s infinite alternate ease-in-out;
    }

    @keyframes slowMove {
      0% { transform: translate(0,0) scale(1); }
      100% { transform: translate(-5%,5%) scale(1.05); }
    }

    .hero-content {
      position: relative;
      z-index: 2;
      max-width: 800px;
    }

    .hero h1 {
      font-size: clamp(3rem, 8vw, 5.5rem);
      font-weight: 900;
      letter-spacing: -0.02em;
      line-height: 1.1;
      margin-bottom: 1.5rem;
      color: white;
    }
    .hero h1 .highlight {
      color: var(--accent-red);
    }

    .hero p {
      font-size: 1.25rem;
      color: rgba(255,255,255,0.8);
      margin-bottom: 2.5rem;
      max-width: 550px;
    }

    /* ----- 痛点卡片（非对称网格） ----- */
    .grid-pain {
      display: grid;
      grid-template-columns: 1fr 1.5fr;
      gap: 2rem;
      margin-top: 2rem;
    }

    .card {
      background: white;
      border-radius: var(--radius-card);
      padding: 2rem;
      box-shadow: var(--shadow-card);
      transition: var(--transition-smooth);
    }

    .card:hover {
      box-shadow: var(--shadow-hover);
      transform: translateY(-4px);
    }

    .card-icon {
      width: 48px;
      height: 48px;
      color: var(--accent-red);
      margin-bottom: 1.2rem;
    }

    .card h4 {
      font-size: 1.3rem;
      font-weight: 700;
      color: var(--primary-black);
      margin-bottom: 0.5rem;
    }

    /* ----- 解决方案交错 ----- */
    .grid-solution {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 3rem;
      align-items: center;
      margin-top: 3rem;
    }

    .solution-text h3 {
      font-size: 1.8rem;
      font-weight: 700;
      margin-bottom: 1rem;
    }

    .img-placeholder {
      background: #e9ecef;
      border-radius: var(--radius-img);
      overflow: hidden;
      position: relative;
      aspect-ratio: 4/3;
      display: flex;
      align-items: center;
      justify-content: center;
      color: #adb5bd;
      font-weight: 600;
    }
    .img-placeholder img {
      width: 100%;
      height: 100%;
      object-fit: cover;
    }

    /* ----- 数据展示 ----- */
    .stats-grid {
      display: flex;
      flex-wrap: wrap;
      justify-content: space-around;
      gap: 2rem;
      margin-top: 2.5rem;
    }
    .stat-item {
      text-align: center;
    }
    .stat-number {
      font-size: 5rem;
      font-weight: 900;
      color: var(--accent-red);
      line-height: 1;
    }

    /* ----- 证言非对称 ----- */
    .grid-testimonials {
      display: grid;
      grid-template-columns: 1fr 1.5fr;
      gap: 2rem;
      margin-top: 2rem;
    }

    .testimonial-left {
      background: white;
      padding: 2rem;
      border-radius: var(--radius-card);
    }

    .testimonial-right {
      background: #dee2e6;
      border-radius: var(--radius-card);
      aspect-ratio: 4/3;
      display: flex;
      align-items: center;
      justify-content: center;
    }

    /* ----- FAQ手风琴 ----- */
    .faq-list {
      margin-top: 2rem;
    }
    .faq-item {
      border-bottom: 1px solid var(--border-light);
      background: white;
    }
    .faq-question {
      padding: 1.2rem 0;
      display: flex;
      justify-content: space-between;
      align-items: center;
      font-weight: 700;
      font-size: 1.1rem;
      cursor: pointer;
      color: var(--primary-black);
    }
    .faq-icon {
      transition: transform 0.3s;
      font-size: 1.5rem;
      color: var(--accent-red);
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.4s ease, padding 0.3s;
      color: var(--text-body);
    }
    .faq-item.active .faq-answer {
      max-height: 200px;
      padding-bottom: 1.2rem;
    }
    .faq-item.active .faq-icon {
      transform: rotate(45deg);
    }

    /* ----- CTA 终极区 ----- */
    .cta-full {
      background: var(--gray-dark);
      color: white;
      text-align: center;
      padding: 5rem 0;
    }

    /* ----- 页脚 ----- */
    .footer {
      background: var(--gray-dark);
      color: #F1F2F6;
      padding: 3rem 0 1.5rem;
    }
    .footer-grid {
      display: grid;
      grid-template-columns: 1fr 1fr 1fr;
      gap: 2rem;
    }
    .social-icons {
      display: flex;
      gap: 1rem;
      margin-top: 1rem;
    }
    .social-circle {
      width: 36px;
      height: 36px;
      background: #4a4d54;
      border-radius: 50%;
      transition: 0.2s;
    }
    .social-circle:hover {
      background: var(--accent-red);
    }
    .copyright {
      border-top: 1px solid rgba(255,255,255,0.1);
      margin-top: 2rem;
      padding-top: 1.5rem;
      font-size: 0.85rem;
      color: #8E9198;
      text-align: center;
    }

    /* ----- 响应式 ----- */
    @media (max-width: 1024px) {
      .grid-solution, .grid-testimonials, .grid-pain {
        grid-template-columns: 1fr;
      }
    }

    @media (max-width: 768px) {
      .nav-links { display: none; }
      .menu-toggle { display: flex; }
      .section { padding: 3rem 0; }
      .hero { text-align: center; }
      .hero p { margin-left: auto; margin-right: auto; }
      .footer-grid { grid-template-columns: 1fr; text-align: center; }
      .social-icons { justify-content: center; }
      .stats-grid { flex-direction: column; align-items: center; }
    }