/* roulang page: index */
:root {
      --panda-black: #1A1A1A;
      --bamboo-cream: #F5F5F0;
      --vivid-green: #00C853;
      --deep-green: #2C3E2D;
      --race-red: #FF3D00;
      --light-gray-green: #E0E0D8;
      --white: #FFFFFF;
      --soft-shadow: 0 4px 20px rgba(0,0,0,0.04), 0 1px 3px rgba(0,0,0,0.06);
      --hover-shadow: 0 12px 32px rgba(0,0,0,0.08);
      --border-radius-card: 12px;
      --border-radius-btn: 8px;
      --font-sans: "PingFang SC", "Microsoft YaHei", "Noto Sans SC", sans-serif;
      --font-number: "Inter", "Roboto", sans-serif;
      --transition-smooth: 0.25s ease;
    }
    * {
      margin: 0;
      padding: 0;
      box-sizing: border-box;
    }
    body {
      font-family: var(--font-sans);
      background-color: var(--bamboo-cream);
      color: var(--panda-black);
      line-height: 1.6;
      -webkit-font-smoothing: antialiased;
    }
    .container {
      max-width: 1200px;
      margin: 0 auto;
      padding: 0 24px;
    }
    h1, h2, h3 {
      font-weight: 700;
      letter-spacing: -0.2px;
    }
    a {
      text-decoration: none;
      color: inherit;
    }
    img {
      max-width: 100%;
      height: auto;
      display: block;
    }
    /* 导航 */
    .main-header {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      background-color: rgba(26,26,26,0.92);
      backdrop-filter: blur(10px);
      z-index: 1000;
      transition: background-color 0.3s;
      border-bottom: 1px solid rgba(255,255,255,0.05);
    }
    .nav-container {
      display: flex;
      align-items: center;
      justify-content: space-between;
      height: 72px;
      max-width: 1200px;
      margin: 0 auto;
      padding: 0 24px;
    }
    .logo {
      font-size: 1.7rem;
      font-weight: 700;
      color: white;
      letter-spacing: 1px;
      display: flex;
      align-items: center;
      gap: 6px;
    }
    .logo span {
      color: var(--vivid-green);
    }
    .nav-links {
      display: flex;
      gap: 32px;
      align-items: center;
    }
    .nav-links a {
      color: rgba(255,255,255,0.85);
      font-weight: 500;
      font-size: 0.95rem;
      transition: color 0.2s;
      position: relative;
      padding: 8px 0;
    }
    .nav-links a:hover,
    .nav-links a.active {
      color: var(--vivid-green);
    }
    .nav-links a.active::after {
      content: '';
      position: absolute;
      bottom: -2px;
      left: 0;
      width: 100%;
      height: 2px;
      background-color: var(--vivid-green);
    }
    .hamburger {
      display: none;
      flex-direction: column;
      gap: 5px;
      cursor: pointer;
      background: transparent;
      border: none;
      padding: 8px;
    }
    .hamburger span {
      width: 25px;
      height: 2px;
      background: white;
      transition: 0.3s;
    }
    /* 区块间距 */
    section {
      padding: 100px 0;
    }
    @media (max-width: 768px) {
      section {
        padding: 70px 0;
      }
      .nav-links {
        position: fixed;
        top: 72px;
        left: 0;
        width: 100%;
        height: calc(100vh - 72px);
        background: rgba(26,26,26,0.98);
        backdrop-filter: blur(15px);
        flex-direction: column;
        align-items: center;
        justify-content: center;
        gap: 40px;
        transform: translateX(100%);
        transition: transform 0.35s ease;
      }
      .nav-links.open {
        transform: translateX(0);
      }
      .hamburger {
        display: flex;
      }
    }
    /* Hero */
    .hero {
      background-color: var(--panda-black);
      min-height: 100vh;
      display: flex;
      align-items: center;
      position: relative;
      overflow: hidden;
      padding-top: 72px;
    }
    .hero-content {
      display: flex;
      align-items: center;
      justify-content: space-between;
      width: 100%;
      gap: 40px;
    }
    .hero-text {
      flex: 1;
      color: white;
    }
    .hero-text h1 {
      font-size: clamp(2.4rem, 5vw, 3.5rem);
      font-weight: 700;
      line-height: 1.2;
      margin-bottom: 20px;
    }
    .hero-text p {
      font-size: 1.2rem;
      opacity: 0.85;
      margin-bottom: 32px;
      max-width: 500px;
    }
    .hero-buttons {
      display: flex;
      gap: 16px;
      flex-wrap: wrap;
    }
    .btn {
      display: inline-block;
      padding: 14px 32px;
      border-radius: var(--border-radius-btn);
      font-weight: 600;
      transition: all 0.25s ease;
      text-align: center;
      font-size: 1rem;
    }
    .btn-primary {
      background: var(--vivid-green);
      color: white;
    }
    .btn-primary:hover {
      background: #00B248;
    }
    .btn-outline {
      border: 2px solid white;
      color: white;
      background: transparent;
    }
    .btn-outline:hover {
      background: white;
      color: var(--panda-black);
    }
    .btn-danger {
      background: var(--race-red);
      color: white;
    }
    .btn-danger:hover {
      background: #D32F2F;
      transform: scale(1.03);
    }
    .hero-image {
      flex: 1;
      position: relative;
      border-radius: 24px;
      overflow: hidden;
      box-shadow: 0 20px 40px rgba(0,0,0,0.5);
    }
    .hero-image img {
      object-fit: cover;
      width: 100%;
      height: 400px;
    }
    @media (max-width: 768px) {
      .hero-content {
        flex-direction: column;
        text-align: center;
      }
      .hero-text p {
        margin-left: auto;
        margin-right: auto;
      }
      .hero-buttons {
        justify-content: center;
      }
    }
    /* 核心优势 非对称 */
    .features-grid {
      display: grid;
      grid-template-columns: 1.5fr 1fr;
      gap: 24px;
    }
    .feature-large {
      background: var(--white);
      border-radius: var(--border-radius-card);
      padding: 40px;
      box-shadow: var(--soft-shadow);
    }
    .feature-small-group {
      display: flex;
      flex-direction: column;
      gap: 24px;
    }
    .feature-item {
      background: var(--white);
      border-radius: var(--border-radius-card);
      padding: 28px;
      box-shadow: var(--soft-shadow);
      transition: var(--transition-smooth);
    }
    .feature-item:hover, .feature-large:hover {
      transform: translateY(-4px);
      box-shadow: var(--hover-shadow);
    }
    .icon-placeholder {
      font-size: 2.5rem;
      color: var(--vivid-green);
      margin-bottom: 16px;
    }
    @media (max-width: 768px) {
      .features-grid {
        grid-template-columns: 1fr;
      }
    }
    /* 产品卡片 */
    .products-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
    }
    .product-card {
      background: var(--white);
      border-radius: var(--border-radius-card);
      overflow: hidden;
      box-shadow: var(--soft-shadow);
      transition: var(--transition-smooth);
    }
    .product-card:hover {
      transform: translateY(-4px);
      box-shadow: var(--hover-shadow);
    }
    .product-card img {
      height: 200px;
      object-fit: cover;
      width: 100%;
    }
    .product-info {
      padding: 24px;
    }
    .product-info h3 {
      margin-bottom: 12px;
    }
    .product-info ul {
      list-style: none;
      margin: 16px 0;
    }
    .product-info li::before {
      content: "●";
      color: var(--vivid-green);
      margin-right: 8px;
    }
    .text-link {
      color: var(--vivid-green);
      font-weight: 600;
    }
    @media (max-width: 1024px) {
      .products-grid {
        grid-template-columns: repeat(2, 1fr);
      }
    }
    @media (max-width: 520px) {
      .products-grid {
        grid-template-columns: 1fr;
      }
    }
    /* 场景交替 */
    .scenario-row {
      display: flex;
      align-items: center;
      gap: 60px;
      margin-bottom: 80px;
    }
    .scenario-row.reverse {
      flex-direction: row-reverse;
    }
    .scenario-img {
      flex: 1;
      border-radius: 16px;
      overflow: hidden;
    }
    .scenario-text {
      flex: 1;
    }
    @media (max-width: 768px) {
      .scenario-row, .scenario-row.reverse {
        flex-direction: column;
      }
    }
    /* 案例墙 */
    .cases-mix {
      display: grid;
      grid-template-columns: 1fr 1fr 0.8fr;
      gap: 24px;
    }
    .case-card {
      background: var(--white);
      padding: 28px;
      border-radius: var(--border-radius-card);
      box-shadow: var(--soft-shadow);
    }
    .big-number {
      font-size: 3.5rem;
      font-weight: 700;
      color: var(--vivid-green);
      font-family: var(--font-number);
    }
    @media (max-width: 768px) {
      .cases-mix {
        grid-template-columns: 1fr;
      }
    }
    /* FAQ */
    .faq-item {
      border-bottom: 1px solid var(--light-gray-green);
    }
    .faq-question {
      padding: 18px 0;
      font-weight: 700;
      cursor: pointer;
      display: flex;
      justify-content: space-between;
      align-items: center;
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.4s ease;
    }
    .faq-answer p {
      padding-bottom: 18px;
      opacity: 0.85;
    }
    /* CTA */
    .cta-section {
      background: var(--panda-black);
      text-align: center;
      color: white;
    }
    /* 页脚 */
    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1fr;
      gap: 30px;
      color: #B0B0B0;
    }
    .footer-grid h4 {
      color: white;
      margin-bottom: 16px;
    }
    @media (max-width: 768px) {
      .footer-grid {
        grid-template-columns: 1fr 1fr;
      }
    }