/* roulang page: index */
:root {
      --primary: #C84B31;
      --primary-hover: #A83D28;
      --secondary: #2B2D42;
      --bg-warm: #FAF7F2;
      --accent: #D9A066;
      --card-bg: rgba(255,255,255,0.92);
      --border-light: #EDE8E0;
      --text-body: #2B2D42;
      --text-muted: #6C6E7A;
      --white: #FFFFFF;
      --shadow-sm: 0 4px 20px rgba(200,75,49,0.08);
      --shadow-hover: 0 12px 32px rgba(200,75,49,0.15);
      --radius-card: 12px;
      --radius-btn: 8px;
      --radius-tag: 6px;
      --font-heading: "PingFang SC", "Microsoft YaHei", "Helvetica Neue", sans-serif;
      --font-number: "Inter", "PingFang SC", sans-serif;
    }
    * {
      box-sizing: border-box;
      margin: 0;
      padding: 0;
    }
    body {
      font-family: var(--font-heading);
      background-color: var(--bg-warm);
      color: var(--text-body);
      line-height: 1.7;
      font-size: 16px;
      -webkit-font-smoothing: antialiased;
    }
    img {
      max-width: 100%;
      height: auto;
      display: block;
    }
    a {
      text-decoration: none;
      color: inherit;
      transition: color 0.2s ease;
    }
    button, .btn {
      cursor: pointer;
      font-family: inherit;
      border: none;
      background: none;
    }
    input {
      font-family: inherit;
      outline: none;
    }
    .container {
      max-width: 1200px;
      margin: 0 auto;
      padding: 0 5%;
    }
    @media (max-width: 1024px) {
      .container {
        padding: 0 4%;
      }
    }
    @media (max-width: 640px) {
      .container {
        padding: 0 20px;
      }
    }

    /* Header & Navigation */
    .site-header {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      height: 72px;
      background: rgba(250,247,242,0.95);
      backdrop-filter: blur(12px);
      z-index: 50;
      display: flex;
      align-items: center;
      box-shadow: 0 1px 8px rgba(0,0,0,0.02);
    }
    .header-inner {
      display: flex;
      justify-content: space-between;
      align-items: center;
      width: 100%;
      max-width: 1200px;
      margin: 0 auto;
      padding: 0 5%;
    }
    .logo-area {
      display: flex;
      flex-direction: column;
      line-height: 1.2;
    }
    .logo-text {
      font-size: 1.8rem;
      font-weight: 700;
      color: var(--secondary);
      letter-spacing: 1px;
    }
    .logo-domain {
      font-size: 0.75rem;
      color: var(--text-muted);
      font-weight: 400;
      letter-spacing: 0.3px;
    }
    .desktop-nav {
      display: flex;
      gap: 2rem;
      align-items: center;
    }
    .desktop-nav a {
      font-size: 0.95rem;
      font-weight: 500;
      color: var(--secondary);
      position: relative;
      padding: 0.3rem 0;
      transition: color 0.2s;
    }
    .desktop-nav a::after {
      content: '';
      position: absolute;
      bottom: -4px;
      left: 0;
      width: 0;
      height: 3px;
      background: var(--primary);
      transition: width 0.2s ease;
      border-radius: 2px;
    }
    .desktop-nav a:hover,
    .desktop-nav a.active {
      color: var(--primary);
    }
    .desktop-nav a:hover::after,
    .desktop-nav a.active::after {
      width: 100%;
    }
    .mobile-menu-toggle {
      display: none;
      background: none;
      border: none;
      font-size: 1.8rem;
      color: var(--secondary);
    }
    @media (max-width: 1024px) {
      .desktop-nav {
        display: none;
      }
      .mobile-menu-toggle {
        display: block;
      }
    }
    .mobile-overlay {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      height: 100%;
      background: rgba(250,247,242,0.98);
      backdrop-filter: blur(8px);
      z-index: 60;
      display: flex;
      flex-direction: column;
      align-items: center;
      justify-content: center;
      gap: 2.5rem;
      transform: translateY(-100%);
      transition: transform 0.35s ease;
    }
    .mobile-overlay.open {
      transform: translateY(0);
    }
    .mobile-overlay a {
      font-size: 1.8rem;
      font-weight: 600;
      color: var(--secondary);
    }
    .close-overlay {
      position: absolute;
      top: 20px;
      right: 25px;
      font-size: 2.2rem;
      background: none;
      border: none;
      color: var(--secondary);
    }

    /* Bottom Tab (mobile) */
    .bottom-tab-bar {
      display: none;
      position: fixed;
      bottom: 0;
      left: 0;
      width: 100%;
      height: 64px;
      background: #FFFFFF;
      box-shadow: 0 -2px 10px rgba(0,0,0,0.04);
      z-index: 55;
      justify-content: space-around;
      align-items: center;
      border-top: 1px solid var(--border-light);
    }
    .tab-item {
      display: flex;
      flex-direction: column;
      align-items: center;
      font-size: 0.7rem;
      color: var(--text-muted);
      gap: 4px;
      transition: color 0.2s;
    }
    .tab-item i {
      font-size: 1.3rem;
    }
    .tab-item.active {
      color: var(--primary);
    }
    @media (max-width: 640px) {
      .bottom-tab-bar {
        display: flex;
      }
      body {
        padding-bottom: 70px;
      }
      .site-header {
        height: 64px;
      }
    }

    /* Hero */
    #hero {
      background: linear-gradient(135deg, rgba(200,75,49,0.25) 0%, rgba(250,247,242,0.1) 70%), url('/assets/images/backpic/back-1.webp') center/cover no-repeat;
      min-height: 90vh;
      display: flex;
      align-items: center;
      margin-top: 72px;
      position: relative;
    }
    .hero-content {
      display: flex;
      align-items: center;
      gap: 3rem;
      width: 100%;
    }
    .hero-text {
      flex: 1;
    }
    .hero-text h1 {
      font-size: 42px;
      font-weight: 700;
      color: var(--secondary);
      line-height: 1.3;
      margin-bottom: 1rem;
    }
    .hero-sub {
      font-size: 1.1rem;
      color: var(--text-body);
      margin-bottom: 2rem;
      max-width: 450px;
    }
    .btn-group {
      display: flex;
      gap: 1rem;
      flex-wrap: wrap;
    }
    .btn-primary {
      background: var(--primary);
      color: white;
      padding: 0.8rem 2rem;
      border-radius: var(--radius-btn);
      font-weight: 600;
      transition: background 0.2s, transform 0.1s;
    }
    .btn-primary:hover {
      background: var(--primary-hover);
    }
    .btn-outline {
      border: 1.5px solid var(--secondary);
      color: var(--secondary);
      padding: 0.8rem 2rem;
      border-radius: var(--radius-btn);
      font-weight: 600;
      background: transparent;
      transition: 0.2s;
    }
    .btn-outline:hover {
      background: var(--secondary);
      color: white;
    }
    @media (max-width: 640px) {
      .hero-content {
        flex-direction: column-reverse;
        text-align: center;
      }
      .hero-text h1 {
        font-size: 30px;
      }
      .hero-sub {
        margin-left: auto;
        margin-right: auto;
      }
      .btn-group {
        justify-content: center;
      }
    }

    /* Sections */
    section {
      padding: 100px 0;
    }
    @media (max-width: 1024px) {
      section {
        padding: 70px 0;
      }
    }
    @media (max-width: 640px) {
      section {
        padding: 50px 0;
      }
    }
    .section-title {
      font-size: 32px;
      font-weight: 700;
      color: var(--secondary);
      margin-bottom: 0.75rem;
    }
    .section-sub {
      color: var(--text-muted);
      margin-bottom: 3rem;
      font-size: 1rem;
    }
    @media (max-width: 640px) {
      .section-title {
        font-size: 24px;
      }
    }

    /* Cards grid */
    .grid-3, .grid-4 {
      display: grid;
      gap: 30px;
    }
    .grid-3 {
      grid-template-columns: repeat(3,1fr);
    }
    .grid-4 {
      grid-template-columns: repeat(4,1fr);
    }
    @media (max-width: 1024px) {
      .grid-3, .grid-4 {
        grid-template-columns: repeat(2,1fr);
      }
    }
    @media (max-width: 640px) {
      .grid-3, .grid-4 {
        grid-template-columns: 1fr;
        gap: 20px;
      }
    }

    .service-card {
      background: var(--card-bg);
      border-radius: var(--radius-card);
      padding: 2rem 1.5rem;
      box-shadow: var(--shadow-sm);
      transition: all 0.25s ease;
      border: 1px solid var(--border-light);
    }
    .service-card:hover {
      transform: translateY(-6px);
      box-shadow: var(--shadow-hover);
      border-color: var(--primary);
    }
    .service-icon {
      font-size: 2rem;
      color: var(--accent);
      margin-bottom: 1.2rem;
    }
    .service-card h3 {
      font-size: 1.3rem;
      font-weight: 650;
      margin-bottom: 0.5rem;
    }
    .stat-number {
      font-family: var(--font-number);
      font-size: 48px;
      font-weight: 700;
      color: var(--primary);
      line-height: 1.1;
    }
    .advantage-card {
      background: var(--card-bg);
      border-radius: var(--radius-card);
      padding: 1.8rem;
      text-align: center;
      box-shadow: var(--shadow-sm);
    }

    .showcase-card {
      background: white;
      border-radius: var(--radius-card);
      overflow: hidden;
      box-shadow: var(--shadow-sm);
      transition: 0.2s;
    }
    .showcase-card:hover {
      transform: translateY(-4px);
      box-shadow: var(--shadow-hover);
    }
    .showcase-img {
      height: 200px;
      background-size: cover;
      background-position: center;
      transition: transform 0.3s;
    }
    .showcase-card:hover .showcase-img {
      transform: scale(1.03);
    }

    .faq-item {
      background: white;
      margin-bottom: 12px;
      border-radius: var(--radius-card);
      border-left: 4px solid var(--primary);
    }
    .faq-question {
      padding: 1.2rem 1.5rem;
      font-weight: 600;
      display: flex;
      justify-content: space-between;
      align-items: center;
      background: white;
    }
    .faq-answer {
      background: #F5F0EA;
      padding: 0 1.5rem 1.2rem;
      font-size: 0.95rem;
      display: none;
    }
    .faq-item.active .faq-answer {
      display: block;
    }
    .faq-item.active {
      border-left-color: var(--accent);
    }

    #contact-cta {
      background: linear-gradient(135deg, var(--primary) 0%, var(--secondary) 100%);
      color: white;
      text-align: center;
    }
    .contact-form {
      display: flex;
      max-width: 500px;
      margin: 2rem auto 0;
      gap: 1rem;
    }
    .contact-form input {
      flex:1;
      padding: 0.9rem;
      border-radius: var(--radius-btn);
      border: none;
      background: rgba(255,255,255,0.9);
    }
    @media(max-width:640px){
      .contact-form{
        flex-direction: column;
      }
    }

    footer {
      background: var(--secondary);
      color: #ccc;
      padding: 3rem 0 1.5rem;
    }
    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr;
      gap: 2rem;
    }
    @media(max-width:640px){
      .footer-grid{
        grid-template-columns:1fr;
      }
    }