/* roulang page: index */
/* ----- 设计变量 ----- */
    :root {
      --primary: #E9402B;
      --primary-dark: #C5301F;
      --secondary-bg: #1A1A2E;
      --accent: #F5A623;
      --accent-hover: #E0940F;
      --success: #10B981;
      --warning: #EF4444;
      --bg-light: #FAFAFA;
      --text-dark: #1A1A2E;
      --text-secondary: #6B7280;
      --text-on-dark: #FFFFFF;
      --border-light: rgba(0,0,0,0.06);
      --border-strong: rgba(0,0,0,0.1);
      --radius-card: 12px;
      --radius-btn: 8px;
      --radius-tag: 6px;
      --shadow-card: 0 4px 20px rgba(0,0,0,0.06);
      --shadow-hover: 0 12px 32px rgba(0,0,0,0.12);
      --font-title: 'Noto Sans SC', sans-serif;
      --font-body: 'Noto Sans SC', sans-serif;
      --font-number: 'Inter', sans-serif;
      --font-mono: 'Space Mono', monospace;
      --container-max: 1280px;
      --header-height: 72px;
    }

    /* ----- 基础重置 ----- */
    *, *::before, *::after {
      box-sizing: border-box;
      margin: 0;
      padding: 0;
    }
    html {
      scroll-behavior: smooth;
      scroll-padding-top: var(--header-height);
    }
    body {
      font-family: var(--font-body);
      background-color: var(--bg-light);
      color: var(--text-dark);
      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, background 0.2s ease;
    }
    button, .btn {
      cursor: pointer;
      font-family: var(--font-body);
      border: none;
      background: transparent;
    }
    ul, ol {
      list-style: none;
    }
    .container {
      max-width: var(--container-max);
      margin: 0 auto;
      padding: 0 24px;
      width: 100%;
    }

    /* ----- 导航 (极简高端文字导航) ----- */
    .site-header {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      height: var(--header-height);
      background: rgba(255,255,255,0.85);
      backdrop-filter: blur(12px);
      -webkit-backdrop-filter: blur(12px);
      border-bottom: 1px solid var(--border-light);
      z-index: 1000;
      display: flex;
      align-items: center;
    }
    .header-inner {
      display: flex;
      justify-content: space-between;
      align-items: center;
      width: 100%;
    }
    .logo {
      font-family: var(--font-title);
      font-weight: 900;
      font-size: 1.5rem;
      letter-spacing: 0.5px;
      color: var(--text-dark);
      display: flex;
      align-items: center;
      gap: 6px;
    }
    .logo span {
      color: var(--primary);
    }
    .nav-menu {
      display: flex;
      gap: 2rem;
      align-items: center;
      font-weight: 500;
      font-size: 0.95rem;
      color: var(--text-dark);
    }
    .nav-menu a {
      position: relative;
      padding: 4px 0;
      transition: color 0.2s;
    }
    .nav-menu a:hover,
    .nav-menu a.active {
      color: var(--primary);
    }
    .nav-menu a::after {
      content: '';
      position: absolute;
      bottom: -6px;
      left: 0;
      width: 100%;
      height: 2px;
      background: var(--primary);
      transform: scaleX(0);
      transition: transform 0.2s ease;
      border-radius: 2px;
    }
    .nav-menu a:hover::after,
    .nav-menu a.active::after {
      transform: scaleX(1);
    }
    .hamburger {
      display: none;
      flex-direction: column;
      gap: 5px;
      cursor: pointer;
      background: transparent;
      border: none;
    }
    .hamburger span {
      display: block;
      width: 24px;
      height: 2px;
      background: var(--text-dark);
      transition: 0.2s;
    }
    .hamburger span:nth-child(2) {
      width: 16px;
      align-self: flex-end;
    }
    @media (max-width: 768px) {
      .nav-menu {
        display: none;
      }
      .hamburger {
        display: flex;
      }
      .mobile-nav {
        position: fixed;
        top: var(--header-height);
        left: 0;
        width: 100%;
        background: rgba(26,26,46,0.97);
        backdrop-filter: blur(10px);
        flex-direction: column;
        padding: 2rem;
        gap: 1.5rem;
        display: none;
        z-index: 999;
      }
      .mobile-nav.active {
        display: flex;
      }
      .mobile-nav a {
        color: white;
        font-size: 1.2rem;
        font-weight: 600;
        border-bottom: 1px solid rgba(255,255,255,0.15);
        padding-bottom: 0.5rem;
      }
    }

    /* ----- 按钮系统 ----- */
    .btn-primary {
      background: var(--primary);
      color: white;
      border-radius: var(--radius-btn);
      padding: 14px 32px;
      font-weight: 600;
      font-size: 1rem;
      display: inline-flex;
      align-items: center;
      justify-content: center;
      gap: 8px;
      transition: background 0.2s, transform 0.2s, box-shadow 0.2s;
      box-shadow: 0 4px 10px rgba(233,64,43,0.2);
    }
    .btn-primary:hover {
      background: var(--primary-dark);
      transform: scale(1.03);
      box-shadow: 0 8px 18px rgba(233,64,43,0.3);
    }
    .btn-outline {
      background: transparent;
      border: 2px solid var(--primary);
      color: var(--primary);
      border-radius: var(--radius-btn);
      padding: 12px 30px;
      font-weight: 600;
      transition: 0.2s;
    }
    .btn-outline:hover {
      background: var(--primary);
      color: white;
    }
    .btn-ghost {
      background: transparent;
      border: 2px solid white;
      color: white;
      border-radius: var(--radius-btn);
      padding: 12px 30px;
      font-weight: 600;
      transition: 0.2s;
    }
    .btn-ghost:hover {
      background: white;
      color: var(--text-dark);
    }
    .btn-accent {
      background: var(--accent);
      color: var(--text-dark);
      font-weight: 700;
      padding: 16px 40px;
      border-radius: var(--radius-btn);
      transition: 0.2s;
    }
    .btn-accent:hover {
      background: var(--accent-hover);
      transform: scale(1.02);
    }

    /* ----- Hero 双栏 ----- */
    .hero {
      padding: calc(var(--header-height) + 40px) 0 60px;
      background: linear-gradient(105deg, #FAFAFA 60%, #1A1A2E 60%);
      min-height: 90vh;
      display: flex;
      align-items: center;
    }
    .hero-grid {
      display: grid;
      grid-template-columns: 1.2fr 0.8fr;
      gap: 3rem;
      align-items: center;
    }
    .hero-left h1 {
      font-family: var(--font-title);
      font-size: 3rem;
      font-weight: 900;
      line-height: 1.2;
      color: var(--text-dark);
      margin-bottom: 1.5rem;
    }
    .hero-left .badge {
      background: var(--primary);
      color: white;
      display: inline-block;
      padding: 6px 14px;
      border-radius: 20px;
      font-size: 0.8rem;
      font-weight: 700;
      margin-bottom: 1.2rem;
    }
    .hero-sub {
      font-size: 1.2rem;
      color: var(--text-secondary);
      margin-bottom: 2rem;
      max-width: 500px;
    }
    .hero-buttons {
      display: flex;
      gap: 1rem;
      flex-wrap: wrap;
    }
    .hero-right {
      background: url('/assets/images/backpic/back-1.webp') center/cover no-repeat;
      border-radius: 24px;
      min-height: 400px;
      box-shadow: 0 20px 35px rgba(0,0,0,0.3);
    }
    @media (max-width: 1024px) {
      .hero {
        background: #FAFAFA;
      }
      .hero-grid {
        grid-template-columns: 1fr;
        text-align: center;
      }
      .hero-right {
        height: 300px;
      }
      .hero-sub {
        margin: 0 auto 1.5rem;
      }
      .hero-buttons {
        justify-content: center;
      }
    }

    /* ----- 亮点卡片网格 ----- */
    .features {
      padding: 80px 0;
    }
    .section-title {
      font-family: var(--font-title);
      font-size: 2.25rem;
      font-weight: 800;
      margin-bottom: 1rem;
      text-align: center;
    }
    .features-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
      margin-top: 3rem;
    }
    .feature-card {
      background: white;
      border-radius: var(--radius-card);
      padding: 32px 24px;
      box-shadow: var(--shadow-card);
      transition: 0.3s ease;
      border: 1px solid transparent;
    }
    .feature-card:hover {
      transform: translateY(-4px);
      box-shadow: var(--shadow-hover);
      border-color: var(--primary);
    }
    .feature-icon {
      width: 48px;
      height: 48px;
      background: rgba(233,64,43,0.1);
      border-radius: 12px;
      display: flex;
      align-items: center;
      justify-content: center;
      font-size: 24px;
      color: var(--primary);
      margin-bottom: 1.5rem;
    }
    .feature-card h3 {
      font-size: 1.5rem;
      font-weight: 700;
      margin-bottom: 0.5rem;
    }
    .feature-stat {
      font-family: var(--font-number);
      font-weight: 800;
      font-size: 2rem;
      color: var(--primary);
    }
    @media (max-width: 768px) {
      .features-grid {
        grid-template-columns: 1fr;
      }
    }

    /* 案例瀑布流 */
    .cases {
      padding: 80px 0;
      background: white;
    }
    .masonry {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
      margin-top: 3rem;
    }
    .case-card {
      border-radius: var(--radius-card);
      overflow: hidden;
      background: white;
      box-shadow: var(--shadow-card);
      transition: 0.3s;
    }
    .case-card:hover {
      transform: translateY(-5px);
    }
    .case-img {
      height: 200px;
      background-size: cover;
      background-position: center;
      transition: 0.4s;
    }
    .case-card:hover .case-img {
      transform: scale(1.05);
    }
    .case-tag {
      background: var(--accent);
      color: #1A1A2E;
      font-size: 0.75rem;
      font-weight: 700;
      padding: 4px 10px;
      border-radius: 4px;
    }
    @media (max-width: 1024px) {
      .masonry {
        grid-template-columns: repeat(2, 1fr);
      }
    }
    @media (max-width: 640px) {
      .masonry {
        grid-template-columns: 1fr;
      }
    }

    /* 方案对比 */
    .pricing {
      padding: 80px 0;
    }
    .pricing-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
      margin-top: 3rem;
    }
    .plan-card {
      background: white;
      border-radius: var(--radius-card);
      padding: 2rem;
      box-shadow: var(--shadow-card);
      border: 2px solid transparent;
    }
    .plan-card.featured {
      border-color: var(--primary);
      position: relative;
    }
    .popular-tag {
      background: var(--accent);
      color: #1A1A2E;
      font-weight: 700;
      font-size: 0.8rem;
      padding: 4px 12px;
      border-radius: 20px;
      position: absolute;
      top: -12px;
      right: 20px;
    }
    @media (max-width: 768px) {
      .pricing-grid {
        grid-template-columns: 1fr;
      }
    }

    /* FAQ */
    .faq {
      padding: 80px 0;
      background: white;
    }
    .faq-item {
      border-bottom: 1px solid var(--border-light);
      padding: 20px 0;
    }
    .faq-question {
      font-weight: 700;
      font-size: 1.1rem;
      cursor: pointer;
      display: flex;
      justify-content: space-between;
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: 0.3s;
      color: var(--text-secondary);
    }
    .faq-item.active .faq-answer {
      max-height: 200px;
      margin-top: 12px;
    }

    /* CTA 横幅 */
    .cta-banner {
      background: var(--secondary-bg);
      padding: 80px 0;
      text-align: center;
      color: white;
      position: relative;
      overflow: hidden;
    }
    .cta-banner::before {
      content: '';
      position: absolute;
      width: 300px;
      height: 300px;
      background: radial-gradient(circle, rgba(233,64,43,0.4) 0%, transparent 70%);
      top: -50px;
      right: -50px;
    }

    /* 页脚 */
    .footer {
      background: #111827;
      color: #D1D5DB;
      padding: 60px 0 30px;
    }
    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1fr;
      gap: 2rem;
    }
    @media (max-width: 768px) {
      .footer-grid {
        grid-template-columns: 1fr;
      }
    }

    /* 其他工具 */
    .text-accent { color: var(--accent); }