/* roulang page: index */
:root {
      --green: #0A8F3C;
      --orange: #F15A24;
      --dark: #1A1D20;
      --warm-light: #F5F3EF;
      --charcoal: #2C2C2C;
      --mid-gray: #6B6B6B;
      --white: #FFFFFF;
      --radius-card: 12px;
      --radius-btn: 8px;
      --radius-tag: 6px;
      --shadow-sm: 0 2px 12px rgba(0,0,0,0.06);
      --shadow-hover: 0 6px 20px rgba(10,143,60,0.12);
      --transition: 0.2s ease;
    }
    * {
      margin: 0;
      padding: 0;
      box-sizing: border-box;
    }
    body {
      font-family: "PingFang SC", "Microsoft YaHei", "Noto Sans SC", system-ui, sans-serif;
      background-color: var(--warm-light);
      color: var(--charcoal);
      line-height: 1.7;
      font-size: 16px;
      -webkit-font-smoothing: antialiased;
    }
    .container {
      max-width: 1200px;
      margin: 0 auto;
      padding: 0 24px;
    }
    h1, h2, h3 {
      font-weight: 600;
    }
    a {
      text-decoration: none;
      color: inherit;
    }
    img {
      max-width: 100%;
      display: block;
    }
    button, input, textarea {
      font-family: inherit;
      outline: none;
      border: none;
    }
    /* 导航 */
    #nav {
      position: fixed;
      top: 0;
      left: 0;
      right: 0;
      background: rgba(255,255,255,0.94);
      backdrop-filter: blur(10px);
      box-shadow: 0 1px 8px rgba(0,0,0,0.04);
      z-index: 1000;
      transition: var(--transition);
    }
    .nav-container {
      display: flex;
      align-items: center;
      justify-content: space-between;
      max-width: 1200px;
      margin: 0 auto;
      padding: 12px 24px;
    }
    .logo {
      display: flex;
      align-items: center;
      gap: 8px;
      font-weight: 700;
      font-size: 1.4rem;
      letter-spacing: -0.3px;
    }
    .logo-icon {
      width: 28px;
      height: 28px;
      background: var(--green);
      border-radius: 6px;
      display: flex;
      align-items: center;
      justify-content: center;
      color: white;
      font-size: 16px;
    }
    .nav-links {
      display: flex;
      gap: 32px;
      align-items: center;
      font-weight: 500;
      color: #444;
    }
    .nav-links a {
      padding: 4px 0;
      transition: color 0.2s;
      font-size: 15px;
    }
    .nav-links a:hover {
      color: var(--green);
    }
    .btn-primary {
      background: var(--orange);
      color: white;
      padding: 10px 22px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      letter-spacing: 0.5px;
      transition: background 0.25s, transform 0.1s;
      display: inline-block;
      cursor: pointer;
    }
    .btn-primary:hover {
      background: #E04A1A;
    }
    .btn-primary:active {
      transform: scale(0.97);
    }
    .btn-outline {
      border: 2px solid var(--green);
      color: var(--green);
      background: transparent;
      padding: 10px 22px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      transition: 0.25s;
      display: inline-block;
    }
    .btn-outline:hover {
      background: var(--green);
      color: white;
    }
    .btn-ghost {
      border: 2px solid white;
      color: white;
      background: transparent;
      padding: 10px 28px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      transition: 0.25s;
      display: inline-block;
    }
    .btn-ghost:hover {
      background: white;
      color: var(--green);
    }
    .hamburger {
      display: none;
      flex-direction: column;
      gap: 5px;
      cursor: pointer;
      padding: 8px;
    }
    .hamburger span {
      width: 25px;
      height: 2.2px;
      background: #2c2c2c;
      border-radius: 2px;
    }
    .mobile-menu {
      display: none;
      position: fixed;
      top: 68px;
      left: 0;
      width: 100%;
      background: white;
      box-shadow: 0 8px 24px rgba(0,0,0,0.1);
      padding: 24px;
      flex-direction: column;
      gap: 20px;
      z-index: 999;
    }
    .mobile-menu a {
      font-size: 18px;
      font-weight: 500;
      display: block;
    }
    /* Hero */
    #hero {
      padding-top: 90px;
      display: flex;
      align-items: center;
      min-height: 600px;
      background: var(--warm-light);
    }
    .hero-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      align-items: center;
      gap: 40px;
    }
    .hero-left {
      padding-right: 20px;
    }
    .hero-left h1 {
      font-size: 2.8rem;
      font-weight: 700;
      line-height: 1.2;
      letter-spacing: -0.5px;
      color: var(--charcoal);
      margin-bottom: 18px;
    }
    .hero-sub {
      font-size: 18px;
      color: var(--mid-gray);
      margin-bottom: 28px;
      line-height: 1.6;
    }
    .trust-data {
      display: flex;
      gap: 32px;
      margin-top: 26px;
    }
    .trust-item {
      font-weight: 700;
      color: var(--dark);
      font-size: 15px;
    }
    .trust-item span {
      color: var(--green);
      font-size: 1.5rem;
      margin-right: 4px;
    }
    .hero-right {
      position: relative;
      border-radius: 24px;
      overflow: hidden;
      clip-path: polygon(12% 0, 100% 0, 100% 88%, 88% 100%, 0 100%, 0 12%);
      background: var(--dark);
    }
    .hero-right img {
      width: 100%;
      height: 420px;
      object-fit: cover;
      opacity: 0.9;
    }
    .floating-tag {
      position: absolute;
      bottom: 24px;
      right: 24px;
      background: white;
      padding: 12px 20px;
      border-radius: var(--radius-card);
      font-weight: 600;
      font-size: 14px;
      color: var(--green);
      box-shadow: var(--shadow-sm);
    }
    .btn-group {
      display: flex;
      gap: 16px;
    }
    /* Sections */
    section {
      padding: 80px 0;
    }
    .section-title {
      text-align: center;
      margin-bottom: 16px;
      font-size: 2rem;
      font-weight: 600;
    }
    .section-sub {
      text-align: center;
      color: var(--mid-gray);
      margin-bottom: 48px;
    }
    .grid-3 {
      display: grid;
      grid-template-columns: repeat(3,1fr);
      gap: 27px;
    }
    .grid-4 {
      display: grid;
      grid-template-columns: repeat(4,1fr);
      gap: 24px;
    }
    .advantage-card {
      background: var(--white);
      padding: 32px 22px;
      border-radius: var(--radius-card);
      text-align: center;
      box-shadow: var(--shadow-sm);
      transition: 0.25s;
    }
    .advantage-card:hover {
      transform: translateY(-5px);
      box-shadow: var(--shadow-hover);
    }
    .advantage-icon {
      font-size: 2.5rem;
      margin-bottom: 18px;
      color: var(--green);
    }
    .service-card {
      background: white;
      border-radius: var(--radius-card);
      overflow: hidden;
      box-shadow: var(--shadow-sm);
      transition: 0.3s;
    }
    .service-card:hover {
      transform: translateY(-6px);
      box-shadow: var(--shadow-hover);
    }
    .service-img {
      height: 160px;
      background-size: cover;
      background-position: center;
    }
    .service-body {
      padding: 20px;
    }
    .cases-masonry {
      display: grid;
      grid-template-columns: repeat(3,1fr);
      gap: 24px;
    }
    .case-card {
      position: relative;
      border-radius: var(--radius-card);
      overflow: hidden;
      min-height: 260px;
      background: #2c2c2c;
    }
    .case-card img {
      width: 100%;
      height: auto;
      display: block;
    }
    .case-overlay {
      position: absolute;
      bottom: 0;
      left: 0;
      right: 0;
      background: linear-gradient(transparent, rgba(0,0,0,0.7));
      color: white;
      padding: 28px 20px 16px;
    }
    .compare-table {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 28px;
    }
    .compare-col {
      background: white;
      border-radius: var(--radius-card);
      padding: 32px;
      box-shadow: var(--shadow-sm);
    }
    .compare-col.right {
      border: 2px solid var(--green);
      background: #f8fdf9;
    }
    .compare-item {
      display: flex;
      justify-content: space-between;
      margin: 20px 0;
      font-weight: 500;
    }
    .faq-list {
      max-width: 800px;
      margin: 0 auto;
    }
    .faq-item {
      border-bottom: 1px solid #e0e0e0;
      padding: 18px 0;
    }
    .faq-question {
      font-weight: 600;
      font-size: 1.1rem;
      display: flex;
      justify-content: space-between;
      cursor: pointer;
      align-items: center;
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.3s ease;
      color: #4b4b4b;
      margin-top: 8px;
    }
    .faq-item.open .faq-answer {
      max-height: 200px;
    }
    #contact {
      background: var(--dark);
      color: white;
    }
    .contact-form {
      display: flex;
      gap: 16px;
      flex-wrap: wrap;
      justify-content: center;
      margin-top: 28px;
    }
    .contact-form input {
      padding: 14px 18px;
      border-radius: 6px;
      flex: 1 1 200px;
    }
    footer {
      background: #15171a;
      color: #ccc;
      padding: 50px 0 20px;
    }
    .footer-grid {
      display: grid;
      grid-template-columns: repeat(4,1fr);
      gap: 30px;
    }
    @media (max-width: 1024px) {
      .hero-grid { grid-template-columns: 1fr; }
      .grid-4 { grid-template-columns: repeat(2,1fr); }
    }
    @media (max-width: 768px) {
      .nav-links { display: none; }
      .hamburger { display: flex; }
      .grid-3, .grid-4, .compare-table, .cases-masonry { grid-template-columns: 1fr; }
      .hero-left h1 { font-size: 2rem; }
      .btn-group { flex-direction: column; }
      .footer-grid { grid-template-columns: 1fr 1fr; }
    }