/* roulang page: index */
:root {
      --red-ant: #E43D2A;
      --red-ant-hover: #C53020;
      --black-earth: #1B1B1F;
      --yellow-signal: #FFB800;
      --yellow-signal-hover: #E6A500;
      --white-sand: #F7F4F0;
      --white-card: #FFFFFF;
      --text-heading: #1B1B1F;
      --text-body: #3D3D42;
      --text-muted: #6B6B70;
      --border-light: #D1D1D6;
      --shadow-card: 0 4px 20px rgba(0,0,0,0.06);
      --shadow-card-hover: 0 12px 32px rgba(0,0,0,0.1);
      --shadow-red: 0 8px 30px rgba(228,61,42,0.15);
      --radius-card: 20px;
      --radius-btn: 12px;
      --radius-input: 10px;
      --radius-tag: 50px;
      --nav-width: 88px;
      --container-max: 1200px;
      --transition-speed: 0.25s;
    }

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

    html {
      scroll-behavior: smooth;
      -webkit-font-smoothing: antialiased;
      -moz-osx-font-smoothing: grayscale;
    }

    body {
      font-family: 'Noto Sans SC', 'Inter', 'PingFang SC', sans-serif;
      font-size: 16px;
      line-height: 1.7;
      color: var(--text-body);
      background-color: var(--white-sand);
      overflow-x: hidden;
    }

    /* Layout: Desktop App Shell */
    .app-shell {
      display: flex;
      min-height: 100vh;
    }

    /* Left Navigation */
    .side-nav {
      position: fixed;
      left: 0;
      top: 0;
      width: var(--nav-width);
      height: 100vh;
      background-color: var(--black-earth);
      display: flex;
      flex-direction: column;
      align-items: center;
      justify-content: space-between;
      padding: 32px 0;
      z-index: 1000;
      box-shadow: 2px 0 20px rgba(0,0,0,0.1);
    }

    .nav-logo {
      display: flex;
      flex-direction: column;
      align-items: center;
      text-decoration: none;
    }

    .nav-logo .logo-icon {
      width: 44px;
      height: 44px;
      background-color: var(--red-ant);
      border-radius: 14px;
      display: flex;
      align-items: center;
      justify-content: center;
      color: white;
      font-weight: 700;
      font-size: 20px;
      font-family: 'Oswald', sans-serif;
      margin-bottom: 8px;
      transition: background var(--transition-speed);
    }

    .nav-logo:hover .logo-icon {
      background-color: var(--red-ant-hover);
    }

    .nav-logo .logo-text {
      color: white;
      font-size: 13px;
      font-weight: 500;
      writing-mode: vertical-rl;
      letter-spacing: 2px;
      font-family: 'Noto Sans SC', sans-serif;
    }

    .nav-links {
      list-style: none;
      display: flex;
      flex-direction: column;
      gap: 24px;
      flex: 1;
      justify-content: center;
      margin: 20px 0;
    }

    .nav-links li {
      position: relative;
      display: flex;
      justify-content: center;
    }

    .nav-links a {
      color: rgba(255,255,255,0.65);
      text-decoration: none;
      font-size: 14px;
      font-weight: 500;
      writing-mode: vertical-rl;
      letter-spacing: 2px;
      transition: color var(--transition-speed), transform var(--transition-speed);
      position: relative;
      padding: 8px 4px;
      display: flex;
      align-items: center;
      gap: 6px;
    }

    .nav-links a i {
      font-size: 16px;
      writing-mode: horizontal-tb;
    }

    .nav-links a:hover {
      color: var(--red-ant);
    }

    .nav-links a.active {
      color: white;
    }

    .nav-links a.active::before {
      content: '';
      position: absolute;
      left: -12px;
      top: 50%;
      transform: translateY(-50%);
      width: 3px;
      height: 24px;
      background-color: var(--yellow-signal);
      border-radius: 2px;
    }

    .nav-contact {
      display: flex;
      flex-direction: column;
      gap: 16px;
      color: rgba(255,255,255,0.5);
      font-size: 18px;
      position: relative;
    }

    .nav-contact a {
      color: rgba(255,255,255,0.5);
      transition: color var(--transition-speed);
      text-decoration: none;
    }

    .nav-contact a:hover {
      color: var(--yellow-signal);
    }

    /* Tooltip */
    .nav-contact .tooltip {
      visibility: hidden;
      opacity: 0;
      position: absolute;
      left: calc(100% + 20px);
      top: 50%;
      transform: translateY(-50%);
      background: var(--black-earth);
      color: white;
      padding: 8px 16px;
      border-radius: 6px;
      white-space: nowrap;
      font-size: 13px;
      font-weight: 500;
      transition: opacity 0.2s, visibility 0.2s;
      box-shadow: 0 4px 12px rgba(0,0,0,0.3);
      pointer-events: none;
      z-index: 10;
    }

    .nav-contact a:hover .tooltip {
      visibility: visible;
      opacity: 1;
    }

    /* Main Content */
    .main-content {
      margin-left: var(--nav-width);
      width: calc(100% - var(--nav-width));
      background: var(--white-sand);
    }

    /* Mobile Nav Toggle */
    .mobile-nav-toggle {
      display: none;
      background: none;
      border: none;
      cursor: pointer;
      padding: 8px;
      flex-direction: column;
      gap: 5px;
    }
    .mobile-nav-toggle span {
      display: block;
      width: 24px;
      height: 2px;
      background: var(--yellow-signal);
      border-radius: 2px;
      transition: 0.2s;
    }

    .mobile-top-bar {
      display: none;
    }

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

    /* Section Spacing */
    section {
      padding: 100px 0;
    }

    /* Buttons */
    .btn {
      display: inline-block;
      font-weight: 600;
      text-decoration: none;
      cursor: pointer;
      font-size: 16px;
      transition: all var(--transition-speed);
      border-radius: var(--radius-btn);
      border: 2px solid transparent;
      font-family: inherit;
    }

    .btn-primary {
      background: var(--red-ant);
      color: white;
      padding: 14px 32px;
    }
    .btn-primary:hover {
      background: var(--red-ant-hover);
      transform: translateY(-1px);
      box-shadow: 0 6px 20px rgba(228,61,42,0.3);
    }

    .btn-outline {
      background: transparent;
      border-color: var(--black-earth);
      color: var(--black-earth);
      padding: 14px 32px;
    }
    .btn-outline:hover {
      background: var(--black-earth);
      color: white;
      transform: translateY(-1px);
    }

    .btn-cta {
      background: var(--yellow-signal);
      color: var(--black-earth);
      padding: 16px 36px;
      font-weight: 700;
      border-radius: var(--radius-btn);
      font-size: 17px;
    }
    .btn-cta:hover {
      background: var(--yellow-signal-hover);
      transform: translateY(-2px);
      box-shadow: 0 10px 24px rgba(255,184,0,0.4);
    }

    .btn-tag {
      background: var(--yellow-signal);
      color: var(--black-earth);
      padding: 6px 16px;
      border-radius: var(--radius-tag);
      font-size: 13px;
      font-weight: 600;
      display: inline-block;
      letter-spacing: 0.5px;
      border: none;
    }

    /* Headings */
    h1 {
      font-family: 'Oswald', 'PingFang SC Heavy', 'Impact', sans-serif;
      font-weight: 700;
      line-height: 1.1;
    }
    h2 {
      font-family: 'Oswald', 'PingFang SC Heavy', sans-serif;
      font-weight: 600;
      line-height: 1.2;
      color: var(--text-heading);
    }
    h3 {
      font-weight: 600;
      line-height: 1.3;
      color: var(--text-heading);
    }

    /* Section Titles */
    .section-title-wrapper {
      display: flex;
      align-items: center;
      gap: 16px;
      margin-bottom: 48px;
    }
    .accent-bar {
      width: 4px;
      height: 40px;
      background: var(--yellow-signal);
      border-radius: 2px;
      flex-shrink: 0;
    }

    /* Hero Section */
    .hero-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 60px;
      align-items: center;
      min-height: 85vh;
    }
    .hero-text {
      padding-right: 20px;
    }
    .hero-tag {
      margin-bottom: 20px;
    }
    .hero-title {
      font-size: 56px;
      margin-bottom: 20px;
    }
    .hero-title .line1 { color: var(--red-ant); display: block; }
    .hero-title .line2 { color: var(--black-earth); display: block; }
    .hero-subtitle {
      font-size: 18px;
      color: rgba(27,27,31,0.7);
      max-width: 480px;
      margin-bottom: 32px;
    }
    .hero-buttons {
      display: flex;
      gap: 16px;
      flex-wrap: wrap;
    }
    .hero-image-container {
      position: relative;
      display: flex;
      justify-content: center;
      align-items: center;
    }
    .hero-img {
      width: 100%;
      border-radius: 24px;
      box-shadow: var(--shadow-red);
      object-fit: cover;
      aspect-ratio: 4/3;
    }
    .hero-badge {
      position: absolute;
      bottom: -20px;
      right: -10px;
      background: var(--yellow-signal);
      color: var(--black-earth);
      border-radius: 50%;
      width: 100px;
      height: 100px;
      display: flex;
      flex-direction: column;
      align-items: center;
      justify-content: center;
      font-family: 'Oswald', sans-serif;
      font-weight: 700;
      box-shadow: 0 10px 20px rgba(255,184,0,0.4);
    }
    .hero-badge .big-num {
      font-size: 32px;
      line-height: 1;
    }
    .hero-badge .badge-label {
      font-size: 13px;
      font-weight: 500;
    }

    /* Features - 1 Big + 2 Small */
    .features-grid {
      display: grid;
      grid-template-columns: 1.5fr 0.75fr 0.75fr;
      gap: 24px;
    }
    .feature-card {
      border-radius: var(--radius-card);
      padding: 36px 32px;
      transition: all var(--transition-speed);
      height: 100%;
    }
    .feature-card-large {
      background: linear-gradient(135deg, #E43D2A 0%, #B91C1C 100%);
      color: white;
      box-shadow: var(--shadow-red);
    }
    .feature-card-large h3 {
      color: white;
      font-size: 24px;
      margin: 16px 0 12px;
    }
    .feature-card-large .big-index {
      font-size: 48px;
      font-family: 'Oswald', sans-serif;
      font-weight: 700;
      color: var(--yellow-signal);
    }
    .feature-card-small {
      background: var(--white-card);
      box-shadow: var(--shadow-card);
    }
    .feature-card-small:hover {
      transform: translateY(-4px);
      box-shadow: var(--shadow-card-hover);
    }
    .feature-icon-circle {
      width: 40px;
      height: 40px;
      background: var(--yellow-signal);
      border-radius: 50%;
      display: flex;
      align-items: center;
      justify-content: center;
      color: var(--black-earth);
      font-size: 18px;
      margin-bottom: 16px;
    }

    /* Stats */
    .stats-section {
      background: var(--black-earth);
      padding: 80px 0;
    }
    .stats-grid {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 40px;
      text-align: center;
    }
    .stat-item .stat-number {
      font-family: 'Oswald', sans-serif;
      font-size: 52px;
      font-weight: 700;
      color: var(--yellow-signal);
      line-height: 1.2;
    }
    .stat-item .stat-label {
      color: var(--white-sand);
      font-size: 15px;
      margin-top: 8px;
      opacity: 0.9;
    }

    /* Services - Alternating */
    .service-row {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 60px;
      align-items: center;
      margin-bottom: 80px;
    }
    .service-row.reverse {
      direction: rtl;
    }
    .service-row.reverse .service-text {
      direction: ltr;
    }
    .service-img {
      width: 100%;
      border-radius: 24px;
      box-shadow: var(--shadow-card);
      object-fit: cover;
      aspect-ratio: 4/3;
    }
    .service-tag {
      margin-bottom: 12px;
    }
    .service-list {
      list-style: none;
      margin-top: 16px;
    }
    .service-list li {
      padding-left: 20px;
      position: relative;
      margin-bottom: 8px;
      color: var(--text-body);
    }
    .service-list li::before {
      content: '';
      position: absolute;
      left: 0;
      top: 8px;
      width: 8px;
      height: 8px;
      background: var(--red-ant);
      border-radius: 50%;
    }

    /* Cases Horizontal Scroll */
    .cases-scroll {
      display: flex;
      gap: 24px;
      overflow-x: auto;
      padding-bottom: 20px;
      scroll-snap-type: x mandatory;
      -webkit-overflow-scrolling: touch;
    }
    .cases-scroll::-webkit-scrollbar {
      height: 6px;
    }
    .cases-scroll::-webkit-scrollbar-thumb {
      background: rgba(27,27,31,0.2);
      border-radius: 10px;
    }
    .case-card {
      min-width: 360px;
      max-width: 380px;
      background: white;
      border-radius: var(--radius-card);
      box-shadow: var(--shadow-card);
      scroll-snap-align: start;
      transition: var(--transition-speed);
      flex-shrink: 0;
    }
    .case-card:hover {
      transform: translateY(-4px);
      box-shadow: var(--shadow-card-hover);
    }
    .case-img-wrap {
      position: relative;
      height: 200px;
      overflow: hidden;
      border-radius: 20px 20px 0 0;
    }
    .case-img {
      width: 100%;
      height: 100%;
      object-fit: cover;
    }
    .case-badge {
      position: absolute;
      bottom: 12px;
      left: 16px;
      background: var(--yellow-signal);
      color: var(--black-earth);
      padding: 4px 12px;
      border-radius: 20px;
      font-weight: 700;
      font-size: 14px;
      font-family: 'Oswald', sans-serif;
    }
    .case-info {
      padding: 20px 24px;
    }
    .case-tags {
      display: flex;
      gap: 8px;
      flex-wrap: wrap;
      margin-top: 12px;
    }
    .case-tag {
      border: 1px solid var(--red-ant);
      color: var(--red-ant);
      padding: 2px 10px;
      border-radius: 20px;
      font-size: 12px;
      font-weight: 600;
    }

    /* FAQ */
    .faq-section {
      background: var(--white-sand);
    }
    .faq-list {
      max-width: 720px;
      margin: 0 auto;
    }
    .faq-item {
      background: white;
      border-radius: 14px;
      margin-bottom: 12px;
      box-shadow: 0 2px 8px rgba(0,0,0,0.04);
      overflow: hidden;
    }
    .faq-question {
      padding: 20px 24px;
      font-size: 18px;
      font-weight: 600;
      color: var(--text-heading);
      cursor: pointer;
      display: flex;
      align-items: center;
      gap: 12px;
      transition: color 0.2s;
      user-select: none;
    }
    .faq-dot {
      width: 8px;
      height: 8px;
      background: var(--yellow-signal);
      border-radius: 50%;
      flex-shrink: 0;
      transition: transform 0.2s;
    }
    .faq-item.open .faq-dot {
      transform: scale(1.8);
      background: var(--red-ant);
    }
    .faq-item.open .faq-question {
      color: var(--red-ant);
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.35s ease, padding 0.35s ease;
      padding: 0 24px;
      color: var(--text-body);
      border-top: 1px solid transparent;
    }
    .faq-item.open .faq-answer {
      max-height: 200px;
      padding: 20px 24px;
      border-top-color: rgba(27,27,31,0.1);
    }

    /* CTA */
    .cta-section {
      background: linear-gradient(135deg, #E43D2A 0%, #A61B1B 100%);
      padding: 80px 0;
      text-align: center;
      position: relative;
      overflow: hidden;
    }
    .cta-section::before {
      content: '';
      position: absolute;
      inset: 0;
      background-image: radial-gradient(circle at 20% 30%, rgba(255,255,255,0.03) 1px, transparent 1px);
      background-size: 30px 30px;
      opacity: 0.4;
    }
    .cta-title {
      color: white;
      font-size: 38px;
      margin-bottom: 12px;
      position: relative;
    }
    .cta-sub {
      color: rgba(255,255,255,0.8);
      margin-bottom: 32px;
      position: relative;
    }
    .cta-form {
      display: flex;
      gap: 12px;
      max-width: 600px;
      margin: 0 auto;
      position: relative;
      flex-wrap: wrap;
      justify-content: center;
    }
    .cta-input {
      flex: 1;
      min-width: 160px;
      padding: 14px 18px;
      border-radius: var(--radius-input);
      border: 1px solid transparent;
      background: white;
      font-size: 16px;
      outline: none;
      transition: box-shadow 0.2s;
    }
    .cta-input:focus {
      border-color: var(--yellow-signal);
      box-shadow: 0 0 0 3px rgba(255,184,0,0.3);
    }

    /* Footer */
    .footer {
      background: var(--black-earth);
      color: var(--white-sand);
      padding: 60px 0 30px;
    }
    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1.5fr 1fr;
      gap: 40px;
    }
    .footer-logo {
      font-size: 24px;
      font-weight: 700;
      color: white;
      margin-bottom: 12px;
      font-family: 'Oswald', sans-serif;
    }
    .footer-logo span { color: var(--red-ant); }
    .footer a {
      color: var(--white-sand);
      text-decoration: none;
      transition: color 0.2s;
      font-size: 14px;
    }
    .footer a:hover { color: var(--yellow-signal); }
    .footer-links {
      list-style: none;
      display: flex;
      flex-direction: column;
      gap: 10px;
    }
    .footer-bottom {
      border-top: 1px solid rgba(255,184,0,0.3);
      margin-top: 40px;
      padding-top: 20px;
      text-align: center;
      font-size: 13px;
      color: rgba(255,255,255,0.5);
    }

    /* Responsive */
    @media (max-width: 1024px) {
      .side-nav { display: none; }
      .main-content { margin-left: 0; width: 100%; }
      .mobile-top-bar {
        display: flex;
        position: fixed;
        top: 0;
        left: 0;
        right: 0;
        height: 56px;
        background: var(--black-earth);
        align-items: center;
        justify-content: space-between;
        padding: 0 20px;
        z-index: 1000;
      }
      .mobile-logo {
        color: white;
        font-weight: 700;
        font-size: 18px;
        text-decoration: none;
        display: flex;
        align-items: center;
        gap: 8px;
      }
      .mobile-nav-toggle { display: flex; }
      .mobile-drawer {
        position: fixed;
        top: 0;
        right: -100%;
        width: 80%;
        max-width: 320px;
        height: 100vh;
        background: var(--black-earth);
        z-index: 1100;
        transition: right 0.3s;
        padding: 24px;
        display: flex;
        flex-direction: column;
      }
      .mobile-drawer.open { right: 0; }
      .drawer-close {
        align-self: flex-end;
        background: none;
        border: none;
        color: white;
        font-size: 24px;
        cursor: pointer;
      }
      .drawer-nav {
        list-style: none;
        margin-top: 40px;
        display: flex;
        flex-direction: column;
        gap: 20px;
      }
      .drawer-nav a {
        color: rgba(255,255,255,0.8);
        font-size: 20px;
        text-decoration: none;
        font-weight: 500;
      }
      .drawer-nav a:hover { color: var(--red-ant); }
      .container { padding: 0 24px; }
      section { padding: 60px 0; }
      .hero-grid { grid-template-columns: 1fr; gap: 40px; }
      .hero-image-container { order: -1; }
      .features-grid { grid-template-columns: 1fr; }
      .stats-grid { grid-template-columns: 1fr 1fr; }
      .service-row { grid-template-columns: 1fr; gap: 30px; }
      .service-row.reverse { direction: ltr; }
      .case-card { min-width: 280px; }
      .footer-grid { grid-template-columns: 1fr 1fr; }
      .cta-form { flex-direction: column; align-items: center; }
      .cta-input { width: 100%; }
    }

    @media (max-width: 768px) {
      .hero-title { font-size: 40px; }
      .stats-grid { grid-template-columns: 1fr 1fr; gap: 24px; }
      .stat-number { font-size: 36px; }
      .footer-grid { grid-template-columns: 1fr; }
      .cta-title { font-size: 28px; }
    }