/* roulang page: index */
* {
      margin: 0;
      padding: 0;
      box-sizing: border-box;
    }

    :root {
      --color-primary: #B31B1B;
      --color-primary-dark: #8A1010;
      --color-secondary: #2C3E50;
      --color-accent: #D4AF37;
      --color-bg-primary: #FFFFFF;
      --color-bg-secondary: #F8F9FA;
      --color-bg-dark: #1A1A1A;
      --color-text-primary: #1A1A1A;
      --color-text-secondary: #6C757D;
      --color-text-on-dark: #FFFFFF;
      --color-border: #E9ECEF;
      --font-display: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
      --font-body: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
      --font-mono: 'JetBrains Mono', 'Courier New', monospace;
      --spacing-unit: 8px;
      --container-max-width: 1280px;
      --grid-gap: 32px;
      --border-radius-sm: 2px;
      --border-radius-md: 4px;
      --border-radius-lg: 0px;
      --box-shadow-card: 0 4px 20px rgba(0,0,0,0.03);
      --box-shadow-card-hover: 0 20px 40px rgba(178, 27, 27, 0.08);
      --transition-base: 0.3s cubic-bezier(0.25, 0.8, 0.25, 1.2);
    }

    html {
      scroll-behavior: smooth;
    }

    body {
      font-family: var(--font-body);
      font-size: 1rem;
      line-height: 1.7;
      color: var(--color-text-primary);
      background-color: var(--color-bg-primary);
      -webkit-font-smoothing: antialiased;
      -moz-osx-font-smoothing: grayscale;
    }

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

    a {
      text-decoration: none;
      color: inherit;
    }

    button, input {
      font-family: inherit;
      outline: none;
      border: none;
      background: none;
    }

    .container {
      max-width: var(--container-max-width);
      margin: 0 auto;
      padding: 0 24px;
    }

    /* 导航栏 */
    .navbar {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      height: 80px;
      display: flex;
      align-items: center;
      justify-content: space-between;
      padding: 0 48px;
      z-index: 1000;
      transition: background-color 0.3s ease, box-shadow 0.3s ease;
      background-color: rgba(0,0,0,0.25);
      backdrop-filter: blur(8px);
    }

    .navbar.scrolled {
      background-color: rgba(26,26,26,0.98);
      box-shadow: 0 1px 0 var(--color-border);
    }

    .logo {
      font-family: var(--font-display);
      font-weight: 700;
      font-size: 1.8rem;
      letter-spacing: -0.02em;
      color: white;
      transition: color 0.3s ease;
      z-index: 1001;
    }

    .nav-links {
      display: flex;
      gap: 40px;
      align-items: center;
    }

    .nav-links a {
      font-family: var(--font-body);
      font-weight: 500;
      font-size: 0.9rem;
      text-transform: uppercase;
      letter-spacing: 0.12em;
      color: rgba(255,255,255,0.85);
      position: relative;
      padding: 8px 0;
      transition: color 0.3s ease;
    }

    .nav-links a::after {
      content: '';
      position: absolute;
      bottom: 0;
      left: 50%;
      transform: translateX(-50%);
      width: 0;
      height: 2px;
      background-color: var(--color-primary);
      transition: width 0.3s ease;
    }

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

    .nav-links a:hover::after {
      width: 100%;
    }

    .hamburger {
      display: none;
      flex-direction: column;
      justify-content: center;
      align-items: center;
      width: 32px;
      height: 32px;
      cursor: pointer;
      z-index: 1001;
      gap: 8px;
    }

    .hamburger .line {
      width: 28px;
      height: 2px;
      background-color: white;
      transition: transform 0.3s ease, opacity 0.3s ease;
    }

    .hamburger .line:first-child {
      width: 20px;
      align-self: flex-end;
    }

    .hamburger.active .line:first-child {
      transform: rotate(45deg) translate(3px, 3px);
      width: 28px;
    }

    .hamburger.active .line:last-child {
      transform: rotate(-45deg) translate(3px, -3px);
    }

    .mobile-menu {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      height: 100vh;
      background-color: var(--color-bg-dark);
      display: flex;
      flex-direction: column;
      justify-content: center;
      align-items: flex-end;
      padding: 48px;
      z-index: 999;
      opacity: 0;
      pointer-events: none;
      transition: opacity 0.4s ease;
    }

    .mobile-menu.active {
      opacity: 1;
      pointer-events: auto;
    }

    .mobile-menu a {
      font-family: var(--font-display);
      font-size: 2.5rem;
      font-weight: 700;
      color: white;
      margin-bottom: 32px;
      text-transform: uppercase;
      letter-spacing: 0.1em;
    }

    /* Hero */
    .hero {
      min-height: 100vh;
      display: flex;
      align-items: center;
      background-color: #0D0D0D;
      background-image: url('/assets/images/backpic/back-1.webp');
      background-size: cover;
      background-position: center 30%;
      position: relative;
      padding: 120px 0 80px;
    }

    .hero::before {
      content: '';
      position: absolute;
      top: 0;
      left: 0;
      width: 100%;
      height: 100%;
      background: linear-gradient(90deg, rgba(0,0,0,0.75) 0%, rgba(0,0,0,0.2) 70%);
    }

    .hero .container {
      display: flex;
      align-items: center;
      gap: 64px;
      position: relative;
      z-index: 2;
      width: 100%;
    }

    .hero-content {
      flex: 0 0 60%;
    }

    .hero-visual {
      flex: 0 0 35%;
      display: flex;
      justify-content: flex-end;
    }

    .hero-image {
      width: 100%;
      max-width: 480px;
      aspect-ratio: 3/4;
      object-fit: cover;
      border-left: 4px solid var(--color-primary);
      filter: grayscale(30%) contrast(1.1);
      box-shadow: 20px 20px 0 rgba(178,27,27,0.15);
    }

    .hero h1 {
      font-family: var(--font-display);
      font-size: clamp(3.5rem, 8vw, 6rem);
      font-weight: 900;
      line-height: 0.9;
      letter-spacing: -0.03em;
      color: white;
      margin-bottom: 24px;
      text-transform: uppercase;
    }

    .hero-subtitle {
      font-family: var(--font-body);
      font-size: 1.2rem;
      letter-spacing: 0.25em;
      color: rgba(255,255,255,0.7);
      margin-bottom: 48px;
    }

    .hero-buttons {
      display: flex;
      gap: 32px;
      align-items: center;
      flex-wrap: wrap;
    }

    .btn-primary {
      background-color: var(--color-primary);
      color: white;
      font-family: var(--font-mono);
      font-weight: 500;
      font-size: 0.9rem;
      letter-spacing: 0.15em;
      text-transform: uppercase;
      padding: 18px 48px;
      border: 2px solid transparent;
      cursor: pointer;
      transition: background-color 0.3s ease, color 0.3s ease;
      display: inline-block;
    }

    .btn-primary:hover {
      background-color: var(--color-text-primary);
      color: white;
    }

    .btn-ghost {
      background: transparent;
      color: white;
      font-family: var(--font-mono);
      font-weight: 500;
      font-size: 0.9rem;
      letter-spacing: 0.15em;
      text-transform: uppercase;
      padding: 18px 0;
      border-bottom: 2px solid rgba(255,255,255,0.8);
      cursor: pointer;
      transition: border-color 0.3s ease, color 0.3s ease;
      display: inline-block;
    }

    .btn-ghost:hover {
      border-bottom-color: var(--color-primary);
      color: var(--color-primary);
    }

    /* 通用区块 */
    section {
      padding: 120px 0;
    }

    .bg-secondary {
      background-color: var(--color-bg-secondary);
    }

    .section-label {
      font-family: var(--font-mono);
      font-size: 0.8rem;
      font-weight: 500;
      letter-spacing: 0.1em;
      text-transform: uppercase;
      color: var(--color-primary);
      margin-bottom: 16px;
    }

    h2 {
      font-family: var(--font-display);
      font-size: clamp(2.5rem, 5vw, 3.5rem);
      font-weight: 700;
      line-height: 1.1;
      letter-spacing: -0.02em;
      margin-bottom: 24px;
      color: var(--color-text-primary);
    }

    /* 亮点网格 */
    .highlights-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 0;
      margin-top: 48px;
      border-top: 1px solid var(--color-border);
    }

    .highlight-card {
      padding: 48px 32px;
      border-bottom: 1px solid var(--color-border);
      border-right: 1px solid var(--color-border);
      transition: background-color 0.2s ease;
    }

    .highlight-card:nth-child(3n) {
      border-right: none;
    }

    .highlight-icon {
      width: 40px;
      height: 40px;
      color: var(--color-secondary);
      margin-bottom: 24px;
      transition: color 0.3s ease;
    }

    .highlight-card h4 {
      font-family: var(--font-body);
      font-size: 1rem;
      font-weight: 600;
      letter-spacing: 0.1em;
      text-transform: uppercase;
      margin-bottom: 12px;
      transition: color 0.3s ease;
    }

    .highlight-card p {
      color: var(--color-text-secondary);
      font-size: 0.95rem;
    }

    .highlight-card:hover .highlight-icon,
    .highlight-card:hover h4 {
      color: var(--color-primary);
    }

    /* 案例瀑布流 */
    .cases-masonry {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
      margin-top: 48px;
    }

    .case-card {
      background: white;
      border: 1px solid var(--color-border);
      transition: transform 0.4s ease, box-shadow 0.4s ease;
    }

    .case-image {
      aspect-ratio: 4/3;
      overflow: hidden;
    }

    .case-image img {
      width: 100%;
      height: 100%;
      object-fit: cover;
      filter: grayscale(100%);
      transition: filter 0.4s ease, transform 0.4s ease;
    }

    .case-card:hover {
      transform: translateY(-8px);
      box-shadow: var(--box-shadow-card-hover);
    }

    .case-card:hover .case-image img {
      filter: grayscale(0%);
      transform: scale(1.03);
    }

    .case-info {
      padding: 24px;
    }

    .case-info h3 {
      font-family: var(--font-display);
      font-weight: 600;
      font-size: 1.3rem;
      margin-bottom: 8px;
    }

    .case-tag {
      font-family: var(--font-mono);
      font-size: 0.7rem;
      text-transform: uppercase;
      letter-spacing: 0.1em;
      color: var(--color-primary);
    }

    /* 对比表 */
    .compare-wrapper {
      display: flex;
      margin-top: 48px;
      border: 1px solid var(--color-border);
    }

    .compare-col {
      flex: 1;
      padding: 48px;
    }

    .compare-col.featured {
      background-color: rgba(178,27,27,0.02);
    }

    .compare-divider {
      width: 1px;
      background: linear-gradient(to bottom, transparent, var(--color-accent), transparent);
    }

    .compare-title {
      font-family: var(--font-display);
      font-weight: 700;
      font-size: 1.8rem;
      margin-bottom: 32px;
    }

    .compare-item {
      display: flex;
      justify-content: space-between;
      padding: 20px 0;
      border-bottom: 1px solid var(--color-border);
      font-size: 0.95rem;
    }

    /* FAQ */
    .faq-list {
      max-width: 800px;
      margin: 48px auto 0;
    }

    .faq-item {
      border-bottom: 1px solid var(--color-border);
    }

    .faq-question {
      display: flex;
      justify-content: space-between;
      align-items: center;
      padding: 28px 0;
      cursor: pointer;
      font-weight: 600;
      font-size: 1.1rem;
    }

    .faq-icon {
      font-size: 1.8rem;
      font-weight: 300;
      transition: transform 0.3s ease;
    }

    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.4s ease, padding 0.4s ease;
      color: var(--color-text-secondary);
    }

    .faq-item.active .faq-answer {
      max-height: 200px;
      padding-bottom: 24px;
    }

    .faq-item.active .faq-icon {
      transform: rotate(45deg);
    }

    /* CTA */
    .cta-section {
      background-color: var(--color-bg-dark);
      padding: 100px 0;
    }

    .cta-content {
      text-align: center;
      color: white;
    }

    .cta-content h2 {
      color: white;
    }

    .cta-form {
      display: flex;
      max-width: 560px;
      margin: 48px auto 0;
    }

    .cta-input {
      flex: 1;
      height: 60px;
      background: transparent;
      border-bottom: 1px solid rgba(255,255,255,0.4);
      color: white;
      padding: 0 16px;
      font-size: 1rem;
      transition: border-color 0.3s ease;
    }

    .cta-input:focus {
      border-bottom: 2px solid var(--color-primary);
    }

    .cta-submit {
      height: 60px;
      padding: 0 40px;
      background: var(--color-primary);
      color: white;
      font-family: var(--font-mono);
      text-transform: uppercase;
      letter-spacing: 0.1em;
      cursor: pointer;
      border: none;
      transition: background 0.3s;
    }

    .cta-submit:hover {
      background: var(--color-text-primary);
    }

    /* Footer */
    .footer {
      background-color: #0F0F0F;
      padding: 80px 0 40px;
    }

    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1fr;
      gap: 48px;
    }

    .footer-brand p {
      color: #AAA;
      margin-top: 16px;
      max-width: 280px;
    }

    .footer-col h4 {
      color: white;
      font-weight: 600;
      margin-bottom: 24px;
      text-transform: uppercase;
    }

    .footer-col a {
      display: block;
      color: #AAA;
      margin-bottom: 12px;
      transition: color 0.3s;
    }

    .footer-col a:hover {
      color: var(--color-primary);
    }

    .footer-bottom {
      margin-top: 64px;
      padding-top: 32px;
      border-top: 1px solid #333;
      font-family: var(--font-mono);
      font-size: 0.8rem;
      color: #666;
      letter-spacing: 0.1em;
      display: flex;
      justify-content: space-between;
    }

    /* 响应式 */
    @media (max-width: 992px) {
      .hero .container {
        flex-direction: column;
      }
      .hero-visual {
        justify-content: center;
        margin-top: 40px;
      }
      .highlights-grid {
        grid-template-columns: 1fr 1fr;
      }
      .cases-masonry {
        grid-template-columns: 1fr 1fr;
      }
      .compare-wrapper {
        flex-direction: column;
      }
      .compare-divider {
        width: 100%;
        height: 1px;
      }
      .footer-grid {
        grid-template-columns: 1fr 1fr;
      }
    }

    @media (max-width: 768px) {
      .nav-links {
        display: none;
      }
      .hamburger {
        display: flex;
      }
      .navbar {
        padding: 0 24px;
      }
      .highlights-grid {
        grid-template-columns: 1fr;
      }
      .highlight-card {
        border-right: none;
      }
      .cases-masonry {
        grid-template-columns: 1fr;
      }
      .hero h1 {
        font-size: 3rem;
      }
      section {
        padding: 80px 0;
      }
      .cta-form {
        flex-direction: column;
      }
      .cta-submit {
        width: 100%;
        margin-top: 16px;
      }
    }