/* roulang page: index */
:root {
      --color-primary: #1E2A2B;
      --color-accent: #C5A46B;
      --color-accent-hover: #B08D4A;
      --color-bg: #F8F9FA;
      --color-white: #FFFFFF;
      --color-text: #4A5568;
      --color-heading: #1E2A2B;
      --color-muted: #718096;
      --color-light-gray: #E2E8F0;
      --color-faq-bg: #F1F3F5;
      --color-footer-bg: #1E2A2B;
      --border-radius-card: 16px;
      --border-radius-btn: 8px;
      --shadow-card: 0 10px 25px -5px rgba(0,0,0,0.03), 0 4px 10px -6px rgba(0,0,0,0.02);
      --shadow-card-hover: 0 20px 35px -10px rgba(0,0,0,0.08), 0 8px 14px -6px rgba(30,42,43,0.05);
      --font-sans: -apple-system, BlinkMacSystemFont, "PingFang SC", "Microsoft YaHei", "Helvetica Neue", sans-serif;
    }
    * {
      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: 1.7;
      font-size: 16px;
      -webkit-font-smoothing: antialiased;
    }
    .container {
      max-width: 1280px;
      margin: 0 auto;
      padding: 0 32px;
    }
   h1, h2, h3, h4 {
      color: var(--color-heading);
      font-weight: 700;
      line-height: 1.25;
    }
    a {
      color: inherit;
      text-decoration: none;
    }
    img {
      max-width: 100%;
      height: auto;
      display: block;
    }

    /* 导航栏 */
    .header {
      position: fixed;
      top:0;
      left:0;
      width:100%;
      background: rgba(255,255,255,0.92);
      backdrop-filter: blur(12px);
      z-index:100;
      border-bottom: 1px solid rgba(0,0,0,0.02);
    }
    .header .container {
      display:flex;
      align-items:center;
      justify-content:space-between;
      height:70px;
    }
    .logo {
      font-size:24px;
      font-weight:800;
      letter-spacing:-0.3px;
      color:var(--color-primary);
    }
    .nav-links {
      display:flex;
      gap:32px;
      align-items:center;
    }
    .nav-links a {
      position:relative;
      font-weight:500;
      font-size:15px;
      color:var(--color-primary);
      transition: color 0.2s;
      padding:4px 0;
    }
    .nav-links a:after {
      content:'';
      position:absolute;
      bottom:0;
      left:0;
      width:0;
      height:2px;
      background:var(--color-accent);
      transition: width 0.25s ease;
    }
    .nav-links a:hover:after,
    .nav-links a.active:after {
      width:100%;
    }
    .nav-links a.active {
      color:var(--color-accent);
      font-weight:600;
    }
    .menu-toggle {
      display:none;
      background:none;
      border:none;
      font-size:24px;
      color:var(--color-primary);
      cursor:pointer;
    }
    @media(max-width:768px){
      .menu-toggle {
        display:block;
      }
      .nav-links {
        position:fixed;
        top:70px;
        left:0;
        width:100%;
        height:calc(100vh - 70px);
        background:rgba(255,255,255,0.98);
        backdrop-filter:blur(20px);
        flex-direction:column;
        justify-content:center;
        gap:40px;
        transform:translateX(100%);
        transition:transform 0.4s cubic-bezier(0.4,0,0.2,1);
      }
      .nav-links.active{
        transform:translateX(0);
      }
      .nav-links a {
        font-size:22px;
        font-weight:500;
      }
    }

    section {
      padding: 100px 0;
    }
    @media(max-width:768px){
      section {
        padding:70px 0;
      }
      .container {
        padding:0 20px;
      }
    }

    /* 首屏 */
    .hero {
      padding:140px 0 100px;
      background-color: var(--color-bg);
    }
    .hero-grid {
      display:flex;
      align-items:center;
      gap:48px;
    }
    .hero-left {
      flex:1;
    }
    .hero-right {
      flex:1.2;
      border-radius:28px;
      overflow:hidden;
      box-shadow: var(--shadow-card-hover);
    }
    .hero-right img {
      width:100%;
      height:auto;
      aspect-ratio: 4/3;
      object-fit:cover;
      border-radius:28px;
    }
    .hero h1 {
      font-size:clamp(40px,5vw,56px);
      font-weight:800;
      letter-spacing:-1px;
      margin-bottom:20px;
    }
    .hero .subtitle {
      font-size:18px;
      color:var(--color-text);
      max-width:480px;
      margin-bottom:32px;
      line-height:1.7;
    }
    .btn-group {
      display:flex;
      flex-wrap:wrap;
      gap:16px;
    }
    .btn {
      padding:12px 30px;
      font-weight:600;
      border-radius: var(--border-radius-btn);
      transition: all 0.25s;
      font-size:16px;
      cursor:pointer;
      display:inline-block;
      border:none;
    }
    .btn-primary {
       background: var(--color-accent);
       color: var(--color-primary);
    }
    .btn-primary:hover {
       background: var(--color-accent-hover);
    }
    .btn-outline {
       background: transparent;
       color: var(--color-primary);
       border: 1.5px solid var(--color-primary);
    }
    .btn-outline:hover {
       background: var(--color-primary);
       color:#fff;
    }
    @media(max-width:768px){
      .hero-grid {
        flex-direction:column-reverse;
      }
      .hero-right {
        width:100%;
        margin-bottom:20px;
      }
    }

    /* section标题 */
    .section-title {
      text-align:center;
      margin-bottom:64px;
    }
    .section-title h2 {
      font-size:36px;
      font-weight:700;
      position:relative;
      display:inline-block;
    }
    .section-title h2:after {
      content:'';
      position:absolute;
      bottom:-12px;
      left:50%;
      transform:translateX(-50%);
      width:45px;
      height:3px;
      background:var(--color-accent);
      border-radius:3px;
    }

    /* 核心亮点 3x2 */
    .features-grid {
      display:grid;
      grid-template-columns: repeat(3,1fr);
      gap:24px;
    }
    .feature-card {
      background:var(--color-white);
      padding:34px 28px;
      border-radius: var(--border-radius-card);
      box-shadow: var(--shadow-card);
      transition: box-shadow 0.3s;
    }
    .feature-card:hover {
       box-shadow: var(--shadow-card-hover);
    }
    .feature-icon {
      font-size:32px;
      color:var(--color-accent);
      margin-bottom:16px;
      display:inline-block;
    }
    .feature-card h3 {
      font-size:20px;
      font-weight:600;
      margin-bottom:8px;
    }
    .feature-card p {
      color:var(--color-muted);
      font-size:15px;
    }
    @media(max-width:768px){
      .features-grid {
        grid-template-columns: 1fr;
      }
    }

    /* 瀑布流案例 */
    .cases-masonry {
      columns:3;
      column-gap:24px;
    }
    .case-card {
      break-inside:avoid;
      background:var(--color-white);
      border-radius: var(--border-radius-card);
      overflow:hidden;
      margin-bottom:24px;
      box-shadow: var(--shadow-card);
      transition: box-shadow 0.25s;
    }
    .case-card:hover {
       box-shadow: var(--shadow-card-hover);
    }
    .case-img {
      width:100%;
      aspect-ratio: 4/3;
      object-fit:cover;
      transition: transform 0.4s;
    }
    .case-card:hover .case-img {
       transform:scale(1.03);
    }
    .case-content {
      padding:20px;
    }
    .case-tag {
      color:var(--color-accent);
      font-size:13px;
      font-weight:600;
      letter-spacing: 0.3px;
    }
    .case-title {
      font-size:18px;
      font-weight:650;
      margin:8px 0 6px;
    }
    .case-desc {
      color:var(--color-text);
      font-size:15px;
    }
    @media(max-width:768px){
      .cases-masonry {
        columns:1;
      }
    }

    /* 方案对比 */
    .comparison-container {
      display:flex;
      gap:30px;
      max-width:960px;
      margin:0 auto;
      background:var(--color-white);
      padding:30px;
      border-radius: var(--border-radius-card);
      box-shadow: var(--shadow-card);
    }
    .compare-col {
      flex:1;
    }
    .compare-col h3 {
      font-size:22px;
      margin-bottom:16px;
      border-bottom:1px solid var(--color-light-gray);
      padding-bottom:8px;
    }
    .compare-item {
      display:flex;
      align-items:center;
      gap:12px;
      margin:18px 0;
    }
    .old .compare-item {
      color: #A0AEC0;
    }
    .new .compare-item {
      color: var(--color-primary);
      font-weight:500;
    }
    .check-icon {
      background: var(--color-accent);
      color:var(--color-primary);
      border-radius:50%;
      font-size:14px;
      width:22px;height:22px;
      display:inline-flex; align-items:center; justify-content:center;
    }
    .cross-icon {
      background: #FED7D7;
      color:#C53030;
      border-radius:50%;
      font-size:14px;
      width:22px;height:22px;
      display:inline-flex; align-items:center; justify-content:center;
    }
    @media(max-width:768px){
      .comparison-container {
        flex-direction:column;
      }
    }

    /* FAQ */
    .faq-list {
      max-width:780px;
      margin:0 auto;
    }
    .faq-item {
      background:var(--color-white);
      border-radius:12px;
      margin-bottom:14px;
      box-shadow:0 2px 8px rgba(0,0,0,0.02);
      overflow:hidden;
      transition:all 0.2s;
    }
    .faq-question {
      padding:20px 24px;
      font-weight:650;
      font-size:17px;
      cursor:pointer;
      display:flex;
      justify-content:space-between;
      align-items:center;
      color:var(--color-heading);
    }
    .faq-toggle {
      font-size:20px;
      transition: transform 0.3s;
    }
    .faq-answer {
      max-height:0;
      opacity:0;
      overflow:hidden;
      background:var(--color-faq-bg);
      padding:0 24px;
      transition: all 0.35s ease;
      color:var(--color-text);
    }
    .faq-item.open .faq-answer {
      max-height:300px;
      opacity:1;
      padding:20px 24px;
    }
    .faq-item.open .faq-toggle {
       transform: rotate(45deg);
    }

    /* CTA深色 */
    .cta-dark {
      background:var(--color-primary);
      color:white;
      text-align:center;
      padding:80px 20px;
      border-radius:32px 32px 0 0;
      margin-top:40px;
    }
    .cta-dark h2 {
      color:white;
      font-size:36px;
      margin-bottom:16px;
    }
    .cta-dark p {
      opacity:0.85;
      margin-bottom:32px;
    }

    footer {
      background:var(--color-primary);
      color:#A0AEC0;
      padding:60px 0 20px;
      border-top:1px solid rgba(181, 147, 106, 0.3);
    }
    .footer-grid {
      display:grid;
      grid-template-columns:2fr 1fr 1fr 1.5fr;
      gap:30px;
    }
    .footer-col h4 {
      color:white;
      margin-bottom:16px;
      font-weight:600;
    }
    .footer-links a {
       display:block;
       margin:10px 0;
       color:#A0AEC0;
       transition: color 0.2s;
    }
    .footer-links a:hover {color:var(--color-accent);}
    .footer-bottom {
      border-top:1px solid rgba(255,255,255,0.08);
      margin-top:40px;
      padding-top:20px;
      text-align:center;
      font-size:14px;
    }
    .social-icons i {
      font-size:20px;
      margin-right:16px;
      color:#A0AEC0;
      transition: 0.2s;
    }
    .social-icons i:hover {color:var(--color-accent);}
    @media(max-width:768px){
      .footer-grid{
        grid-template-columns:1fr;
      }
    }