/* roulang page: index */
:root {
      --primary: #FF4C00;
      --primary-hover: #E04400;
      --primary-soft: rgba(255, 76, 0, 0.08);
      --secondary: #0D0D0D;
      --bg: #F5F3F0;
      --white: #FFFFFF;
      --text-primary: #1A1A1A;
      --text-secondary: #5C5C5C;
      --text-muted: #8A8A8A;
      --border-light: #E8E5E1;
      --success: #0F7B4E;
      --radius-sm: 8px;
      --radius-md: 12px;
      --radius-lg: 16px;
      --radius-pill: 50px;
      --shadow-card: 0 2px 8px rgba(0,0,0,0.04);
      --shadow-hover: 0 8px 24px rgba(255,76,0,0.12);
      --transition: 0.25s ease;
      --max-width: 1280px;
      --header-height: 72px;
    }

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

    body {
      font-family: "PingFang SC", "Microsoft YaHei", "Helvetica Neue", "Inter", sans-serif;
      background-color: var(--bg);
      color: var(--text-primary);
      line-height: 1.5;
      -webkit-font-smoothing: antialiased;
      -moz-osx-font-smoothing: grayscale;
      overflow-x: hidden;
    }

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

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

    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);
      font-weight: 600;
      white-space: nowrap;
    }

    .container {
      max-width: var(--max-width);
      margin: 0 auto;
      padding: 0 24px;
    }

    /* 导航 */
    #header {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      z-index: 1000;
      height: var(--header-height);
      display: flex;
      align-items: center;
      background: transparent;
      transition: background 0.3s ease, backdrop-filter 0.3s ease;
    }

    #header.scrolled {
      background: rgba(13, 13, 13, 0.92);
      backdrop-filter: blur(8px);
      box-shadow: 0 4px 20px rgba(0,0,0,0.15);
    }

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

    .logo {
      display: flex;
      align-items: center;
      gap: 8px;
      font-size: 1.5rem;
      font-weight: 700;
      color: var(--white);
      letter-spacing: -0.3px;
    }

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

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

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

    .nav-menu a:hover {
      color: var(--primary);
    }

    .nav-cta {
      background: var(--primary);
      color: white !important;
      padding: 10px 24px;
      border-radius: var(--radius-pill);
      font-weight: 600;
      transition: background 0.2s, transform 0.2s;
    }

    .nav-cta:hover {
      background: var(--primary-hover);
      transform: translateY(-1px);
    }

    .hamburger {
      display: none;
      flex-direction: column;
      gap: 5px;
      background: none;
      border: none;
      cursor: pointer;
      padding: 8px;
      z-index: 1001;
    }

    .hamburger span {
      width: 24px;
      height: 2px;
      background: white;
      transition: 0.3s;
      display: block;
    }

    .mobile-menu {
      display: none;
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      height: 100vh;
      background: var(--secondary);
      flex-direction: column;
      align-items: center;
      justify-content: center;
      gap: 40px;
      z-index: 999;
      transform: translateX(100%);
      transition: transform 0.4s ease;
    }

    .mobile-menu.active {
      transform: translateX(0);
      display: flex;
    }

    .mobile-menu a {
      color: white;
      font-size: 1.8rem;
      font-weight: 500;
    }

    /* Hero */
    #hero {
      display: flex;
      min-height: 100vh;
      align-items: center;
      background: var(--secondary);
      position: relative;
      overflow: hidden;
    }

    .hero-content {
      display: grid;
      grid-template-columns: 1fr 1fr;
      align-items: center;
      gap: 60px;
      width: 100%;
      position: relative;
      z-index: 2;
      padding-top: var(--header-height);
    }

    .hero-text h1 {
      font-size: clamp(2.4rem, 5vw, 3.2rem);
      font-weight: 800;
      line-height: 1.15;
      color: white;
      letter-spacing: -0.5px;
      margin-bottom: 1.5rem;
    }

    .hero-text h1 span {
      color: var(--primary);
    }

    .hero-sub {
      font-size: 1.2rem;
      color: rgba(255,255,255,0.8);
      margin-bottom: 2.5rem;
      line-height: 1.6;
    }

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

    .btn-primary {
      background: var(--primary);
      color: white;
      padding: 14px 32px;
      border-radius: var(--radius-sm);
      font-size: 1rem;
      box-shadow: 0 4px 12px rgba(255,76,0,0.25);
    }

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

    .btn-secondary {
      border: 1.5px solid var(--primary);
      color: var(--primary);
      padding: 14px 32px;
      border-radius: var(--radius-sm);
      background: transparent;
    }

    .btn-secondary:hover {
      background: var(--primary-soft);
    }

    .hero-visual {
      position: relative;
      border-radius: var(--radius-lg);
      overflow: hidden;
      aspect-ratio: 4/5;
      max-height: 500px;
      box-shadow: 0 20px 40px rgba(0,0,0,0.4);
    }

    .hero-visual img {
      width: 100%;
      height: 100%;
      object-fit: cover;
    }

    .hero-visual::after {
      content: "";
      position: absolute;
      inset: 0;
      background: linear-gradient(135deg, rgba(255,76,0,0.5) 0%, rgba(13,13,13,0.2) 100%);
    }

    /* 亮点网格 */
    #highlights {
      padding: 100px 0;
    }

    .section-title {
      font-size: 2rem;
      font-weight: 700;
      margin-bottom: 48px;
      text-align: center;
    }

    .grid-3 {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 28px;
      align-items: start;
    }

    .highlight-card {
      background: var(--white);
      padding: 32px 24px;
      border-radius: var(--radius-md);
      box-shadow: var(--shadow-card);
      text-align: center;
    }

    .highlight-card:nth-child(2) {
      transform: translateY(-8px);
    }

    .highlight-number {
      font-size: 2.8rem;
      font-weight: 800;
      color: var(--primary);
      line-height: 1.2;
    }

    .highlight-desc {
      color: var(--text-secondary);
      margin-top: 8px;
    }

    /* 服务卡片 */
    #services {
      padding: 100px 0;
      background: var(--white);
    }

    .grid-2x3 {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
    }

    .service-card {
      background: var(--bg);
      border-radius: var(--radius-md);
      overflow: hidden;
      transition: var(--transition);
      box-shadow: var(--shadow-card);
    }

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

    .service-img {
      height: 160px;
      background-size: cover;
      background-position: center;
    }

    .service-body {
      padding: 20px;
    }

    .service-body h3 {
      font-size: 1.25rem;
      margin-bottom: 8px;
    }

    .text-link {
      color: var(--primary);
      font-weight: 600;
      margin-top: 12px;
      display: inline-flex;
      align-items: center;
      gap: 4px;
    }

    /* 案例瀑布 */
    #showcase {
      padding: 100px 0;
    }

    .masonry-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 20px;
    }

    .showcase-card {
      border-radius: var(--radius-lg);
      overflow: hidden;
      position: relative;
      background: var(--secondary);
      box-shadow: var(--shadow-card);
      transition: 0.3s;
    }

    .showcase-card img {
      transition: 0.4s ease;
    }

    .showcase-card:hover img {
      transform: scale(1.04);
    }

    .showcase-info {
      position: absolute;
      bottom: 0;
      left: 0;
      right: 0;
      padding: 20px;
      background: linear-gradient(transparent, rgba(0,0,0,0.8));
      color: white;
    }

    /* 对比表 */
    #comparison {
      padding: 100px 0;
      background: var(--white);
    }

    .compare-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 32px;
    }

    .compare-col {
      padding: 40px;
      border-radius: var(--radius-lg);
    }

    .compare-left {
      background: #f0f0f0;
      color: var(--text-secondary);
    }

    .compare-right {
      background: var(--secondary);
      color: white;
    }

    .compare-item {
      display: flex;
      align-items: center;
      gap: 12px;
      margin: 20px 0;
    }

    /* FAQ */
    #faq {
      padding: 100px 0;
    }

    .faq-item {
      border-bottom: 1px solid var(--border-light);
      padding: 20px 0;
    }

    .faq-question {
      font-weight: 700;
      display: flex;
      justify-content: space-between;
      cursor: pointer;
    }

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

    /* Footer */
    #footer {
      background: #0A0A0A;
      color: #aaa;
      padding: 60px 0 20px;
    }

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

    @media (max-width: 1024px) {
      .grid-2x3, .masonry-grid { grid-template-columns: repeat(2, 1fr); }
      .compare-grid { grid-template-columns: 1fr; }
      .hero-content { grid-template-columns: 1fr; }
    }

    @media (max-width: 768px) {
      .nav-menu { display: none; }
      .hamburger { display: flex; }
      .grid-3, .grid-2x3, .masonry-grid { grid-template-columns: 1fr; }
      .footer-grid { grid-template-columns: 1fr; }
    }