/* roulang page: index */
:root {
      --primary: #1A1A2E;
      --primary-hover: #14142A;
      --accent: #E2B97B;
      --accent-hover: #c9a05e;
      --highlight: #C45C3A;
      --bg: #FAFAF8;
      --text: #2D2D2D;
      --muted: #6B6B6B;
      --border: #E5E5E0;
      --card-bg: #FFFFFF;
      --shadow-sm: 0 2px 8px rgba(0,0,0,0.04);
      --shadow-md: 0 8px 24px rgba(0,0,0,0.08);
      --radius: 12px;
      --radius-sm: 8px;
      --font-serif: "DM Serif Display", "Noto Serif SC", serif;
      --font-sans: "Inter", "Noto Sans SC", sans-serif;
      --max-width: 1280px;
      --header-height: 72px;
      --section-gap: 120px;
    }

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

    body {
      font-family: var(--font-sans);
      background-color: var(--bg);
      color: var(--text);
      line-height: 1.6;
      font-size: 16px;
      -webkit-font-smoothing: antialiased;
    }

    .container {
      max-width: var(--max-width);
      margin: 0 auto;
      padding: 0 40px;
    }

    h1, h2, h3 {
      font-family: var(--font-serif);
      font-weight: 600;
      color: var(--primary);
    }

    h2 {
      font-size: 2.5rem;
      letter-spacing: -0.02em;
      margin-bottom: 1rem;
    }

    h3 {
      font-size: 1.5rem;
      margin-bottom: 0.5rem;
    }

    p {
      color: var(--muted);
    }

    a {
      text-decoration: none;
      color: inherit;
      transition: color 0.25s ease;
    }

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

    button, .btn {
      font-family: var(--font-sans);
      cursor: pointer;
      border: none;
      background: none;
      transition: all 0.25s ease;
      display: inline-flex;
      align-items: center;
      justify-content: center;
      border-radius: var(--radius-sm);
      font-weight: 500;
      font-size: 0.95rem;
      padding: 0.75rem 1.8rem;
      letter-spacing: 0.02em;
    }

    .btn-primary {
      background: var(--primary);
      color: white;
    }
    .btn-primary:hover {
      background: var(--primary-hover);
      transform: scale(1.02);
    }

    .btn-outline {
      background: transparent;
      border: 1.5px solid var(--primary);
      color: var(--primary);
    }
    .btn-outline:hover {
      background: var(--primary);
      color: white;
    }

    .btn-accent {
      background: var(--accent);
      color: var(--primary);
      font-weight: 600;
    }
    .btn-accent:hover {
      background: var(--highlight);
      color: white;
    }

    /* Header & Navigation */
    .site-header {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      height: var(--header-height);
      background: rgba(250,250,248,0.92);
      backdrop-filter: blur(12px);
      -webkit-backdrop-filter: blur(12px);
      border-bottom: 1px solid var(--border);
      z-index: 100;
      display: flex;
      align-items: center;
    }

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

    .logo {
      font-family: var(--font-serif);
      font-size: 1.8rem;
      font-weight: 700;
      color: var(--primary);
      letter-spacing: -0.02em;
    }
    .logo span {
      color: var(--accent);
      margin-left: 0.2rem;
    }

    .nav-menu {
      display: flex;
      align-items: center;
      gap: 2.5rem;
    }

    .nav-link {
      font-size: 0.9rem;
      font-weight: 500;
      color: var(--text);
      transition: color 0.2s;
      position: relative;
    }
    .nav-link:hover {
      color: var(--primary);
    }
    .nav-link::after {
      content: '';
      position: absolute;
      bottom: -4px;
      left: 0;
      width: 0%;
      height: 2px;
      background: var(--accent);
      transition: width 0.25s ease;
    }
    .nav-link:hover::after {
      width: 100%;
    }

    .hamburger {
      display: none;
      font-size: 1.8rem;
      color: var(--primary);
      cursor: pointer;
    }

    /* Hero */
    .hero {
      min-height: 100vh;
      display: flex;
      align-items: center;
      padding-top: var(--header-height);
      background-image: url('/assets/images/backpic/back-1.webp');
      background-size: cover;
      background-position: center;
      position: relative;
    }
    .hero::before {
      content: '';
      position: absolute;
      top:0; left:0; right:0; bottom:0;
      background: rgba(250,250,248,0.85);
      backdrop-filter: blur(2px);
    }
    .hero .container {
      display: flex;
      align-items: center;
      gap: 3rem;
      position: relative;
      z-index: 2;
    }
    .hero-left {
      flex: 0 0 55%;
    }
    .hero-right {
      flex: 1;
      display: flex;
      justify-content: center;
      align-items: center;
    }
    .hero h1 {
      font-size: 4rem;
      line-height: 1.15;
      margin-bottom: 1.5rem;
      color: var(--primary);
    }
    .hero-subtitle {
      font-size: 1.25rem;
      color: var(--muted);
      margin-bottom: 2.5rem;
      max-width: 480px;
    }
    .hero-buttons {
      display: flex;
      gap: 1.2rem;
      flex-wrap: wrap;
    }
    .abstract-graphic {
      width: 320px;
      height: 320px;
      background: radial-gradient(circle at 30% 30%, var(--accent), transparent 50%);
      border-radius: 50%;
      filter: blur(60px);
      opacity: 0.7;
      animation: float 8s infinite alternate ease-in-out;
      position: relative;
    }
    @keyframes float {
      0% { transform: translateY(0px) rotate(0deg); }
      100% { transform: translateY(-20px) rotate(8deg); }
    }

    /* Sections */
    section {
      padding: var(--section-gap) 0;
    }

    .section-title {
      text-align: center;
      margin-bottom: 3rem;
    }
    .section-title h2 {
      margin-bottom: 0.75rem;
    }
    .section-title p {
      font-size: 1.1rem;
    }

    /* Advantages */
    .advantages-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 2.5rem;
      margin-top: 2rem;
    }
    .advantage-item {
      text-align: center;
      padding: 2rem 1.5rem;
      background: var(--card-bg);
      border: 1px solid var(--border);
      border-radius: var(--radius);
      box-shadow: var(--shadow-sm);
      transition: 0.3s ease;
    }
    .advantage-item:hover {
      box-shadow: var(--shadow-md);
      transform: translateY(-4px);
    }
    .advantage-icon {
      font-size: 2.5rem;
      color: var(--accent);
      margin-bottom: 1.2rem;
    }

    /* Services 2x3 asymmetric */
    .services-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 1.8rem;
    }
    .service-card {
      background: var(--card-bg);
      border: 1px solid var(--border);
      border-radius: var(--radius);
      padding: 2rem;
      box-shadow: var(--shadow-sm);
      transition: 0.3s ease;
      display: flex;
      flex-direction: column;
    }
    .service-card:hover {
      box-shadow: var(--shadow-md);
      transform: translateY(-4px);
    }
    .service-card.wide {
      grid-column: span 1;
    }
    .service-img {
      height: 160px;
      background: #F0F0EB;
      border-radius: 8px;
      margin-bottom: 1.5rem;
      display: flex;
      align-items: center;
      justify-content: center;
      overflow: hidden;
    }
    .service-img img {
      width: 100%;
      height: 100%;
      object-fit: cover;
    }
    .service-tags {
      display: flex;
      gap: 0.5rem;
      flex-wrap: wrap;
      margin-top: 1rem;
    }
    .tag {
      background: #F0F0EB;
      color: var(--text);
      padding: 0.25rem 0.9rem;
      border-radius: 20px;
      font-size: 0.75rem;
      font-weight: 500;
    }

    .second-row {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 1.8rem;
      margin-top: 1.8rem;
    }
    .second-row .service-card {
      padding: 1.8rem;
    }

    /* Process */
    .process-steps {
      display: flex;
      justify-content: space-between;
      gap: 2rem;
      margin-top: 2rem;
    }
    .step {
      flex: 1;
      text-align: center;
      position: relative;
    }
    .step-num {
      width: 56px;
      height: 56px;
      background: var(--primary);
      color: white;
      border-radius: 50%;
      display: flex;
      align-items: center;
      justify-content: center;
      font-family: var(--font-serif);
      font-size: 1.8rem;
      margin: 0 auto 1rem;
    }
    .step h3 {
      font-size: 1.3rem;
    }

    /* Cases交错布局 */
    .case-row {
      display: flex;
      align-items: center;
      gap: 3rem;
      margin-bottom: 3rem;
      background: var(--card-bg);
      border: 1px solid var(--border);
      border-radius: var(--radius);
      overflow: hidden;
      box-shadow: var(--shadow-sm);
      transition: 0.3s;
    }
    .case-row:hover {
      box-shadow: var(--shadow-md);
    }
    .case-img {
      flex: 0 0 45%;
      height: 280px;
      background: #F0F0EB;
    }
    .case-img img {
      width: 100%;
      height: 100%;
      object-fit: cover;
    }
    .case-content {
      padding: 2rem;
      flex:1;
    }
    .case-tags {
      margin: 1rem 0;
    }
    .reverse {
      flex-direction: row-reverse;
    }

    /* Stats */
    .stats-grid {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 2rem;
      text-align: center;
    }
    .stat-number {
      font-family: var(--font-serif);
      font-size: 3.2rem;
      color: var(--primary);
      font-weight: 700;
    }
    .stat-label {
      color: var(--muted);
      margin-top: 0.3rem;
    }

    /* FAQ */
    .faq-list {
      max-width: 800px;
      margin: 0 auto;
    }
    .faq-item {
      border-bottom: 1px solid var(--border);
    }
    .faq-question {
      width: 100%;
      padding: 1.2rem 0;
      display: flex;
      justify-content: space-between;
      align-items: center;
      font-weight: 600;
      font-size: 1.1rem;
      color: var(--text);
      background: transparent;
      border: none;
      cursor: pointer;
      transition: color 0.2s;
    }
    .faq-question i {
      transition: transform 0.3s;
      color: var(--muted);
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.35s ease;
      color: var(--muted);
    }
    .faq-answer p {
      padding-bottom: 1.2rem;
    }
    .faq-item.active .faq-question {
      color: var(--primary);
    }
    .faq-item.active .faq-question i {
      transform: rotate(45deg);
      color: var(--accent);
    }
    .faq-item.active .faq-answer {
      max-height: 200px;
    }

    /* CTA Banner */
    .cta-banner {
      background: var(--primary);
      color: white;
      padding: 5rem 0;
      text-align: center;
      border-radius: 0;
    }
    .cta-banner h2 {
      color: white;
    }
    .cta-banner p {
      color: rgba(255,255,255,0.7);
      margin: 1rem 0 2rem;
    }

    /* Footer */
    .site-footer {
      background: var(--primary);
      color: rgba(255,255,255,0.7);
      padding: 4rem 0 2rem;
      font-size: 0.95rem;
    }
    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1fr;
      gap: 2.5rem;
    }
    .footer-col h4 {
      color: white;
      font-family: var(--font-serif);
      margin-bottom: 1.2rem;
      font-size: 1.2rem;
    }
    .footer-col a {
      display: block;
      margin-bottom: 0.6rem;
      color: rgba(255,255,255,0.65);
    }
    .footer-col a:hover {
      color: var(--accent);
    }
    .copyright {
      margin-top: 3rem;
      padding-top: 1.5rem;
      border-top: 1px solid rgba(255,255,255,0.1);
      display: flex;
      justify-content: space-between;
    }

    @media (max-width: 1024px) {
      .hero h1 { font-size: 3.2rem; }
    }

    @media (max-width: 768px) {
      .container { padding: 0 20px; }
      :root { --section-gap: 80px; }
      .hamburger { display: block; }
      .nav-menu {
        position: fixed; top: var(--header-height); left:0; right:0; bottom:0;
        background: rgba(250,250,248,0.98);
        flex-direction: column;
        justify-content: center;
        gap: 2rem;
        transform: translateX(100%);
        transition: 0.3s;
      }
      .nav-menu.active { transform: translateX(0); }
      .hero .container { flex-direction: column; text-align: center; }
      .hero-left { flex:auto; }
      .hero-right { display: none; }
      .advantages-grid { grid-template-columns: 1fr; }
      .services-grid, .second-row { grid-template-columns: 1fr; }
      .process-steps { flex-direction: column; }
      .stats-grid { grid-template-columns: 1fr 1fr; }
      .case-row, .case-row.reverse { flex-direction: column; }
      .footer-grid { grid-template-columns: 1fr 1fr; }
    }