/* roulang page: index */
:root {
      --color-primary: #C41E3A;
      --color-primary-dark: #A01830;
      --color-dark: #1A1A1A;
      --color-accent: #C8A96E;
      --color-bg: #F5F5F0;
      --color-white: #FFFFFF;
      --color-light-gray: #EAEAE3;
      --color-border: #E0E0D8;
      --color-text: #2C2C2C;
      --color-text-muted: #6B6B6B;
      --font-sans: "PingFang SC", "Microsoft YaHei", "Hiragino Sans GB", "Noto Sans SC", sans-serif;
      --font-number: "Inter", "Helvetica Neue", sans-serif;
      --radius-card: 12px;
      --radius-btn: 8px;
      --shadow-card: 0 2px 12px rgba(0,0,0,0.04);
      --shadow-card-hover: 0 8px 30px rgba(0,0,0,0.08);
      --shadow-nav: 0 2px 20px rgba(0,0,0,0.04);
      --transition-base: 0.3s ease;
      --max-width: 1280px;
      --header-height: 72px;
    }

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

    body {
      font-family: var(--font-sans);
      background-color: var(--color-bg);
      color: var(--color-text);
      line-height: 1.75;
      font-size: 16px;
      -webkit-font-smoothing: antialiased;
      -moz-osx-font-smoothing: grayscale;
    }

    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;
      gap: 8px;
      transition: var(--transition-base);
      font-weight: 600;
      font-size: 1rem;
      border-radius: var(--radius-btn);
      white-space: nowrap;
    }

    .container {
      max-width: var(--max-width);
      margin: 0 auto;
      padding: 0 32px;
    }

    @media (max-width: 640px) {
      .container {
        padding: 0 20px;
      }
    }

    /* 导航 */
    .header {
      position: sticky;
      top: 0;
      z-index: 100;
      background: rgba(255,255,255,0.92);
      backdrop-filter: blur(12px);
      height: var(--header-height);
      display: flex;
      align-items: center;
      border-bottom: 1px solid transparent;
      transition: box-shadow 0.3s, border-color 0.3s;
    }

    .header.scrolled {
      box-shadow: var(--shadow-nav);
      border-bottom-color: rgba(0,0,0,0.04);
    }

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

    .logo {
      font-size: 1.6rem;
      font-weight: 800;
      letter-spacing: -0.02em;
      color: var(--color-dark);
      display: flex;
      align-items: center;
      gap: 6px;
    }

    .logo i {
      color: var(--color-primary);
      font-style: normal;
      font-size: 1.8rem;
      line-height: 1;
      margin-right: 2px;
    }

    .logo span {
      color: var(--color-primary);
    }

    .nav-menu {
      display: flex;
      align-items: center;
      gap: 32px;
      list-style: none;
    }

    .nav-menu a {
      font-weight: 500;
      color: var(--color-text);
      position: relative;
      padding: 8px 0;
      font-size: 0.95rem;
    }

    .nav-menu a::after {
      content: '';
      position: absolute;
      bottom: 0;
      left: 0;
      width: 0;
      height: 2px;
      background: var(--color-primary);
      transition: width 0.3s;
    }

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

    .btn-primary {
      background: var(--color-primary);
      color: white;
      padding: 12px 28px;
      box-shadow: 0 4px 12px rgba(196, 30, 58, 0.2);
    }

    .btn-primary:hover {
      background: var(--color-primary-dark);
      transform: translateY(-2px);
      box-shadow: 0 8px 20px rgba(196, 30, 58, 0.3);
    }

    .btn-outline {
      border: 2px solid var(--color-primary);
      color: var(--color-primary);
      background: transparent;
      padding: 10px 26px;
    }

    .btn-outline:hover {
      background: var(--color-primary);
      color: white;
      transform: translateY(-2px);
    }

    .hamburger {
      display: none;
      flex-direction: column;
      gap: 6px;
      background: none;
      border: none;
      cursor: pointer;
      padding: 4px;
    }

    .hamburger span {
      display: block;
      width: 26px;
      height: 2.5px;
      background: var(--color-dark);
      border-radius: 2px;
      transition: 0.3s;
    }

    @media (max-width: 1024px) {
      .nav-menu {
        gap: 20px;
      }
    }

    @media (max-width: 768px) {
      .hamburger {
        display: flex;
      }

      .nav-menu {
        position: fixed;
        top: var(--header-height);
        left: 0;
        width: 100%;
        background: white;
        flex-direction: column;
        gap: 0;
        box-shadow: 0 20px 30px rgba(0,0,0,0.08);
        transform: translateY(-120%);
        opacity: 0;
        transition: transform 0.4s ease, opacity 0.3s;
        padding: 16px 0;
        z-index: 99;
      }

      .nav-menu.active {
        transform: translateY(0);
        opacity: 1;
      }

      .nav-menu li {
        width: 100%;
        text-align: center;
      }

      .nav-menu a {
        display: block;
        padding: 14px 20px;
        font-size: 1.1rem;
      }
      
      .header .btn-primary {
        display: none;
      }
      
      .mobile-cta {
        display: block;
        margin: 8px 20px;
        text-align: center;
      }
    }

    /* Hero */
    .hero {
      background: linear-gradient(135deg, rgba(26,26,26,0.82) 0%, rgba(26,26,26,0.55) 100%), url('/assets/images/backpic/back-1.webp') center/cover no-repeat;
      min-height: 92vh;
      display: flex;
      align-items: center;
      color: white;
      position: relative;
    }

    .hero-content {
      max-width: 720px;
      animation: fadeUp 0.8s ease;
    }

    .hero h1 {
      font-size: clamp(2.5rem, 6vw, 4rem);
      font-weight: 800;
      letter-spacing: -0.02em;
      line-height: 1.2;
      margin-bottom: 24px;
    }

    .hero h1 span {
      color: var(--color-primary);
      background: rgba(255,255,255,0.1);
      padding: 0 12px;
      border-radius: 8px;
    }

    .hero p {
      font-size: 1.25rem;
      opacity: 0.9;
      margin-bottom: 40px;
      max-width: 560px;
    }

    .hero-buttons {
      display: flex;
      gap: 20px;
      flex-wrap: wrap;
    }

    .text-link {
      color: white;
      border-bottom: 1px solid rgba(255,255,255,0.5);
      padding-bottom: 2px;
      font-weight: 500;
      transition: 0.2s;
    }

    .text-link:hover {
      border-bottom-color: white;
    }

    @keyframes fadeUp {
      0% { opacity: 0; transform: translateY(20px); }
      100% { opacity: 1; transform: translateY(0); }
    }

    /* 通用板块 */
    section {
      padding: 100px 0;
    }

    @media (max-width: 768px) {
      section {
        padding: 70px 0;
      }
    }

    .section-title {
      text-align: center;
      margin-bottom: 60px;
    }

    .section-title h2 {
      font-size: 2.2rem;
      font-weight: 700;
      color: var(--color-dark);
      margin-bottom: 12px;
    }

    .section-title p {
      color: var(--color-text-muted);
      font-size: 1.1rem;
    }

    /* 服务卡片 */
    .grid-3 {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 28px;
    }

    .service-card {
      background: var(--color-white);
      border-radius: var(--radius-card);
      padding: 32px 24px;
      box-shadow: var(--shadow-card);
      transition: var(--transition-base);
    }

    .service-card:hover {
      transform: translateY(-6px);
      box-shadow: var(--shadow-card-hover);
    }

    .service-icon {
      width: 64px;
      height: 64px;
      background: rgba(196,30,58,0.08);
      border-radius: 16px;
      display: flex;
      align-items: center;
      justify-content: center;
      margin-bottom: 24px;
      font-size: 2rem;
      color: var(--color-primary);
    }

    .service-card h3 {
      font-size: 1.4rem;
      margin-bottom: 12px;
    }

    /* 优势数据 */
    .stats-grid {
      display: flex;
      justify-content: space-around;
      text-align: center;
      flex-wrap: wrap;
      gap: 32px;
    }

    .stat-item {
      flex: 1;
      min-width: 160px;
    }

    .stat-number {
      font-family: var(--font-number);
      font-size: 3.5rem;
      font-weight: 800;
      color: var(--color-primary);
      line-height: 1.1;
    }

    .stat-label {
      color: var(--color-dark);
      font-weight: 500;
      margin-top: 8px;
      font-size: 1rem;
    }

    /* 案例卡片 */
    .cases-scroll {
      display: flex;
      gap: 24px;
      overflow-x: auto;
      padding-bottom: 16px;
      scroll-snap-type: x mandatory;
    }

    .case-card {
      flex: 0 0 calc(33.333% - 16px);
      min-width: 280px;
      background: white;
      border-radius: var(--radius-card);
      overflow: hidden;
      box-shadow: var(--shadow-card);
      scroll-snap-align: start;
    }

    .case-img {
      height: 200px;
      background-size: cover;
      background-position: center;
    }

    .case-info {
      padding: 20px;
    }

    .badge {
      background: rgba(196,30,58,0.1);
      color: var(--color-primary);
      font-size: 0.8rem;
      font-weight: 700;
      padding: 4px 12px;
      border-radius: 20px;
      display: inline-block;
      margin-bottom: 8px;
    }

    /* 解决方案 */
    .solution-row {
      display: flex;
      align-items: center;
      gap: 60px;
      margin-bottom: 80px;
    }

    .solution-row.reverse {
      flex-direction: row-reverse;
    }

    .solution-img {
      flex: 1;
      height: 320px;
      background-size: cover;
      background-position: center;
      border-radius: var(--radius-card);
    }

    .solution-text {
      flex: 1;
    }

    .solution-text ul {
      list-style: none;
      margin-top: 20px;
    }

    .solution-text li {
      display: flex;
      align-items: center;
      gap: 12px;
      margin-bottom: 12px;
    }

    .solution-text li::before {
      content: "●";
      color: var(--color-primary);
      font-size: 1.2rem;
    }

    /* FAQ */
    .faq-item {
      border-bottom: 1px solid var(--color-border);
      padding: 20px 0;
    }

    .faq-question {
      font-weight: 700;
      font-size: 1.2rem;
      display: flex;
      justify-content: space-between;
      align-items: center;
      cursor: pointer;
      color: var(--color-dark);
    }

    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.4s ease;
      color: var(--color-text-muted);
    }

    .faq-item.open .faq-answer {
      max-height: 200px;
      margin-top: 12px;
    }

    /* CTA */
    .cta-band {
      background: var(--color-dark);
      color: white;
      text-align: center;
      padding: 80px 0;
    }

    .footer {
      background: #1E1E1E;
      color: #B0B0B0;
      padding: 50px 0 30px;
      font-size: 0.95rem;
    }

    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1fr;
      gap: 40px;
    }

    .footer a {
      color: #CCC;
    }

    .footer a:hover {
      color: white;
    }

    @media (max-width: 768px) {
      .grid-3, .footer-grid {
        grid-template-columns: 1fr;
      }
      .solution-row {
        flex-direction: column;
      }
      .solution-row.reverse {
        flex-direction: column;
      }
      .cases-scroll {
        flex-wrap: nowrap;
      }
      .case-card {
        flex: 0 0 80%;
      }
    }