/* roulang page: index */
:root {
      --primary: #C83C2B;
      --primary-deep: #A83223;
      --primary-glow: rgba(200,60,43,0.12);
      --dark: #1E1E1E;
      --paper: #FAFAF7;
      --card-bg: #FFFFFF;
      --border-light: #E8E5DF;
      --text-main: #2C2C2C;
      --text-muted: #5C5C5C;
      --gold: #D4A853;
      --gold-soft: rgba(212,168,83,0.2);
      --white: #FFFFFF;
      --shadow-sm: 0 2px 12px rgba(0,0,0,0.04);
      --shadow-md: 0 8px 24px rgba(0,0,0,0.08);
      --radius-card: 12px;
      --radius-btn: 8px;
      --radius-tag: 6px;
      --font-title: "PingFang SC", "Microsoft YaHei", "Noto Sans SC", sans-serif;
      --font-body: "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
      --font-number: "DIN Alternate", "PingFang SC", sans-serif;
      --max-width: 1200px;
      --transition: 0.3s ease;
    }
    * {
      margin: 0;
      padding: 0;
      box-sizing: border-box;
    }
    html {
      scroll-behavior: smooth;
    }
    body {
      font-family: var(--font-body);
      background-color: var(--paper);
      color: var(--text-main);
      line-height: 1.7;
      font-size: 16px;
      -webkit-font-smoothing: antialiased;
    }
    .container {
      width: 100%;
      max-width: var(--max-width);
      margin: 0 auto;
      padding: 0 24px;
    }
    img {
      display: block;
      max-width: 100%;
      height: auto;
    }
    a {
      text-decoration: none;
      color: inherit;
      transition: var(--transition);
    }
    button, input, textarea {
      font-family: inherit;
    }

    /* ---------- NAVIGATION ---------- */
    .header {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      z-index: 1000;
      background: rgba(255,255,255,0.92);
      backdrop-filter: blur(8px);
      box-shadow: 0 1px 0 0 transparent;
      transition: background 0.3s, box-shadow 0.3s;
    }
    .header.scrolled {
      background: rgba(255,255,255,0.97);
      box-shadow: 0 1px 8px rgba(0,0,0,0.06);
    }
    .nav-bar {
      display: flex;
      align-items: center;
      justify-content: space-between;
      height: 70px;
    }
    .logo {
      display: flex;
      align-items: baseline;
      gap: 6px;
    }
    .logo-text {
      font-family: var(--font-title);
      font-weight: 700;
      font-size: 24px;
      color: var(--primary);
      letter-spacing: 1px;
    }
    .logo-domain {
      font-size: 12px;
      color: var(--text-muted);
      font-weight: 400;
      margin-left: 2px;
    }
    .nav-links {
      display: flex;
      gap: 28px;
      list-style: none;
    }
    .nav-links a {
      font-size: 15px;
      font-weight: 500;
      color: var(--text-main);
      position: relative;
      padding: 6px 0;
    }
    .nav-links a::after {
      content: '';
      position: absolute;
      left: 0;
      bottom: 0;
      width: 0;
      height: 2px;
      background: var(--primary);
      transition: width 0.25s ease;
    }
    .nav-links a:hover::after,
    .nav-links a.active::after {
      width: 100%;
    }
    .hamburger {
      display: none;
      flex-direction: column;
      gap: 4px;
      cursor: pointer;
      background: none;
      border: none;
      padding: 8px;
    }
    .hamburger span {
      width: 24px;
      height: 2px;
      background: var(--text-main);
      border-radius: 2px;
      transition: 0.3s;
    }
    .mobile-menu {
      display: none;
      position: fixed;
      top: 0;
      right: 0;
      width: 280px;
      height: 100vh;
      background: var(--paper);
      box-shadow: -4px 0 20px rgba(0,0,0,0.1);
      flex-direction: column;
      padding: 80px 32px 32px;
      gap: 24px;
      z-index: 999;
      transform: translateX(100%);
      transition: transform 0.35s ease;
    }
    .mobile-menu.open {
      transform: translateX(0);
    }
    .mobile-menu a {
      font-size: 18px;
      font-weight: 600;
      color: var(--text-main);
      border-bottom: 1px solid var(--border-light);
      padding-bottom: 12px;
    }
    .close-mobile {
      position: absolute;
      top: 24px;
      right: 24px;
      background: none;
      border: none;
      font-size: 28px;
      cursor: pointer;
      color: var(--text-main);
    }

    /* ---------- BUTTONS ---------- */
    .btn {
      display: inline-block;
      font-weight: 600;
      border-radius: var(--radius-btn);
      transition: all 0.25s ease;
      cursor: pointer;
      text-align: center;
    }
    .btn-primary {
      background: var(--primary);
      color: var(--white);
      padding: 14px 32px;
      border: none;
      box-shadow: 0 4px 10px rgba(200,60,43,0.25);
    }
    .btn-primary:hover {
      background: var(--primary-deep);
      transform: translateY(-2px);
      box-shadow: 0 8px 18px rgba(200,60,43,0.35);
    }
    .btn-outline {
      background: transparent;
      border: 2px solid var(--primary);
      color: var(--primary);
      padding: 12px 28px;
    }
    .btn-outline:hover {
      background: var(--primary);
      color: var(--white);
    }

    /* ---------- HERO ---------- */
    .hero {
      padding: 160px 0 100px;
      background: var(--paper);
    }
    .hero-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 48px;
      align-items: center;
    }
    .hero-content h1 {
      font-family: var(--font-title);
      font-size: 48px;
      font-weight: 700;
      line-height: 1.2;
      color: var(--dark);
      margin-bottom: 20px;
    }
    .hero-content .sub {
      font-size: 16px;
      color: var(--text-muted);
      margin-bottom: 32px;
      max-width: 480px;
    }
    .hero-trust {
      margin-top: 16px;
      font-size: 14px;
      color: var(--text-muted);
    }
    .hero-image {
      position: relative;
      border-radius: 16px;
      overflow: hidden;
      box-shadow: var(--shadow-md);
      background: #ddd;
    }
    .hero-image img {
      width: 100%;
      height: auto;
      object-fit: cover;
      aspect-ratio: 4/3;
    }
    .hero-badge {
      position: absolute;
      top: 16px;
      left: 16px;
      background: rgba(200,60,43,0.9);
      color: white;
      padding: 6px 16px;
      border-radius: 20px;
      font-size: 14px;
      font-weight: 600;
      letter-spacing: 1px;
    }
    @media (max-width: 768px) {
      .hero-grid {
        grid-template-columns: 1fr;
        gap: 32px;
      }
      .hero-content h1 {
        font-size: 32px;
      }
      .hero {
        padding: 120px 0 60px;
      }
    }

    /* ---------- SECTIONS ---------- */
    section {
      padding: 100px 0;
    }
    @media (max-width: 768px) {
      section {
        padding: 60px 0;
      }
    }
    .section-title {
      font-family: var(--font-title);
      font-size: 36px;
      font-weight: 700;
      color: var(--dark);
      margin-bottom: 48px;
      text-align: center;
    }
    @media (max-width: 768px) {
      .section-title {
        font-size: 26px;
      }
    }

    /* ABOUT */
    .about-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 48px;
      align-items: center;
    }
    .about-img {
      border-radius: var(--radius-card);
      overflow: hidden;
      box-shadow: var(--shadow-sm);
    }
    .about-stats {
      display: flex;
      gap: 24px;
      margin-top: 24px;
      flex-wrap: wrap;
    }
    .stat-item {
      text-align: center;
    }
    .stat-number {
      font-family: var(--font-number);
      font-size: 36px;
      font-weight: 700;
      color: var(--primary);
    }

    /* SERVICES */
    .cards-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
    }
    .service-card {
      background: var(--card-bg);
      border: 1px solid var(--border-light);
      border-radius: var(--radius-card);
      padding: 32px;
      box-shadow: var(--shadow-sm);
      transition: var(--transition);
    }
    .service-card:hover {
      transform: translateY(-4px);
      box-shadow: var(--shadow-md);
    }
    .service-icon {
      width: 48px;
      height: 48px;
      color: var(--gold);
      margin-bottom: 16px;
    }
    .service-card h3 {
      font-size: 22px;
      margin-bottom: 12px;
    }

    /* ADVANTAGES DARK */
    .dark-bg {
      background: var(--dark);
      color: white;
    }
    .dark-bg .section-title {
      color: white;
    }
    .adv-grid {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 24px;
      text-align: center;
    }
    .adv-number {
      font-family: var(--font-number);
      font-size: 56px;
      font-weight: 700;
      color: var(--gold);
    }

    /* CASES */
    .case-card {
      background: var(--card-bg);
      border-radius: var(--radius-card);
      overflow: hidden;
      box-shadow: var(--shadow-sm);
      transition: var(--transition);
    }
    .case-card:hover {
      transform: translateY(-4px);
      box-shadow: var(--shadow-md);
    }
    .case-img img {
      width: 100%;
      aspect-ratio: 16/10;
      object-fit: cover;
    }

    /* PROCESS */
    .process-steps {
      display: flex;
      justify-content: space-between;
      align-items: center;
      text-align: center;
      flex-wrap: wrap;
      gap: 16px;
    }
    .step-circle {
      width: 56px;
      height: 56px;
      border: 2px solid var(--gold);
      border-radius: 50%;
      display: flex;
      align-items: center;
      justify-content: center;
      font-weight: 700;
      color: var(--primary);
      margin: 0 auto 12px;
      font-size: 20px;
    }

    /* FAQ */
    .faq-list {
      max-width: 800px;
      margin: 0 auto;
    }
    .faq-item {
      border-bottom: 1px solid var(--border-light);
      padding: 16px 0;
    }
    .faq-question {
      display: flex;
      justify-content: space-between;
      font-weight: 600;
      cursor: pointer;
      font-size: 18px;
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.35s ease;
      color: var(--text-muted);
    }

    /* CONTACT */
    .contact-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 48px;
    }
    .form-control {
      width: 100%;
      padding: 14px;
      border: 1px solid var(--border-light);
      border-radius: var(--radius-btn);
      margin-bottom: 16px;
    }
    .form-control:focus {
      outline: none;
      border-color: var(--primary);
      box-shadow: 0 0 0 3px var(--primary-glow);
    }

    /* FOOTER */
    .footer {
      background: var(--dark);
      color: #AAAAAA;
      padding: 48px 0 24px;
    }
    .footer-grid {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 32px;
    }
    @media (max-width: 1024px) {
      .cards-grid, .adv-grid { grid-template-columns: repeat(2, 1fr); }
      .footer-grid { grid-template-columns: repeat(2, 1fr); }
    }
    @media (max-width: 768px) {
      .cards-grid, .adv-grid, .about-grid, .contact-grid, .footer-grid {
        grid-template-columns: 1fr;
      }
      .nav-links { display: none; }
      .hamburger { display: flex; }
    }