/* roulang page: index */
:root {
      --color-bg-dark: #0A0E17;
      --color-bg-light: #F5F7FA;
      --color-accent: #E63946;
      --color-accent-hover: #C1121F;
      --color-text-white: #FFFFFF;
      --color-text-dark: #0A0E17;
      --color-text-gray: #8A8F98;
      --color-text-light-gray: #5A5F66;
      --color-text-muted-dark: #4B5059;
      --color-text-muted-light: #8A8F98;
      --color-border-dark: rgba(255,255,255,0.06);
      --color-border-light: #E5E7EB;
      --color-data-green: #2EC4B6;
      --color-card-dark-hover-bg: #141A24;
      --shadow-dark-card: 0 4px 24px rgba(0,0,0,0.4);
      --shadow-dark-card-hover: 0 8px 40px rgba(0,0,0,0.6);
      --shadow-light-card: 0 2px 16px rgba(0,0,0,0.04);
      --shadow-light-card-hover: 0 8px 30px rgba(0,0,0,0.08);
      --radius-card: 12px;
      --radius-btn: 8px;
      --radius-container: 16px;
      --font-sans: "PingFang SC", "Microsoft YaHei", "Helvetica Neue", system-ui, sans-serif;
      --font-mono: "SF Mono", "Menlo", "Monaco", monospace;
      --transition-smooth: all 0.25s cubic-bezier(0.4, 0, 0.2, 1);
      --container-max: 1280px;
      --spacing-section-desktop: 120px;
      --spacing-section-tablet: 80px;
      --spacing-section-mobile: 60px;
    }

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

    html {
      scroll-behavior: smooth;
      -webkit-tap-highlight-color: transparent;
    }

    body {
      font-family: var(--font-sans);
      line-height: 1.7;
      background-color: var(--color-bg-dark);
      color: var(--color-text-white);
      -webkit-font-smoothing: antialiased;
      text-rendering: optimizeLegibility;
      overflow-x: hidden;
    }

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

    a {
      text-decoration: none;
      color: inherit;
      transition: var(--transition-smooth);
    }

    button, input, textarea {
      font-family: inherit;
    }

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

    /* 导航 PC */
    .nav-pc {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      height: 72px;
      background: rgba(255,255,255,0.98);
      backdrop-filter: blur(12px);
      display: flex;
      align-items: center;
      justify-content: space-between;
      padding: 0 32px;
      z-index: 1000;
      border-bottom: 1px solid rgba(0,0,0,0.04);
      box-shadow: 0 1px 0 rgba(0,0,0,0.04);
      transition: box-shadow 0.25s ease;
    }
    .nav-pc.scrolled {
      box-shadow: 0 4px 20px rgba(0,0,0,0.06);
    }
    .logo {
      font-weight: 700;
      font-size: 1.6rem;
      letter-spacing: -0.05em;
      color: var(--color-text-dark);
    }
    .logo span {
      color: var(--color-accent);
    }
    .logo small {
      font-size: 0.7rem;
      font-weight: 400;
      color: var(--color-text-light-gray);
      margin-left: 4px;
      letter-spacing: 0;
    }
    .nav-links {
      display: flex;
      gap: 32px;
      align-items: center;
    }
    .nav-links a {
      font-weight: 500;
      font-size: 0.95rem;
      color: var(--color-text-dark);
      transition: color 0.2s;
      position: relative;
    }
    .nav-links a:hover {
      color: var(--color-accent);
    }
    .nav-links a::after {
      content: '';
      position: absolute;
      bottom: -4px;
      left: 0;
      width: 0;
      height: 2px;
      background: var(--color-accent);
      transition: width 0.2s ease;
    }
    .nav-links a:hover::after {
      width: 100%;
    }
    .btn-nav-cta {
      background: var(--color-accent);
      color: white;
      padding: 10px 24px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      font-size: 0.9rem;
      transition: var(--transition-smooth);
      border: none;
      cursor: pointer;
      white-space: nowrap;
    }
    .btn-nav-cta:hover {
      background: var(--color-accent-hover);
      transform: scale(1.03);
    }

    /* 移动端底部导航 */
    .nav-mobile-bottom {
      position: fixed;
      bottom: 0;
      left: 0;
      width: 100%;
      height: 56px;
      background: var(--color-bg-dark);
      display: none;
      justify-content: space-around;
      align-items: center;
      z-index: 1001;
      border-top: 1px solid var(--color-border-dark);
      padding: 0 16px;
      box-shadow: 0 -4px 20px rgba(0,0,0,0.4);
    }
    .nav-mobile-item {
      display: flex;
      flex-direction: column;
      align-items: center;
      justify-content: center;
      color: var(--color-text-muted-dark);
      font-size: 0.7rem;
      font-weight: 500;
      gap: 4px;
      transition: color 0.2s;
      cursor: pointer;
    }
    .nav-mobile-item.active {
      color: var(--color-accent);
    }
    .nav-mobile-item i {
      font-size: 1.3rem;
      width: 24px;
      text-align: center;
    }

    /* 通用板块样式 */
    section {
      padding-top: var(--spacing-section-desktop);
      padding-bottom: var(--spacing-section-desktop);
    }

    .section-title {
      font-size: 2.5rem;
      line-height: 3rem;
      font-weight: 600;
      letter-spacing: -0.02em;
      margin-bottom: 1.5rem;
      text-align: center;
    }

    .btn {
      display: inline-flex;
      align-items: center;
      justify-content: center;
      padding: 14px 32px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      font-size: 1rem;
      transition: var(--transition-smooth);
      cursor: pointer;
      border: none;
      line-height: 1.2;
    }
    .btn-primary {
      background: var(--color-accent);
      color: white;
      box-shadow: 0 4px 14px rgba(230,57,70,0.3);
    }
    .btn-primary:hover {
      background: var(--color-accent-hover);
      transform: scale(1.03);
    }
    .btn-outline {
      background: transparent;
      border: 2px solid white;
      color: white;
    }
    .btn-outline:hover {
      background: white;
      color: var(--color-bg-dark);
    }

    /* Hero板块 */
    .hero {
      padding-top: 140px;
      padding-bottom: 80px;
      background: var(--color-bg-dark);
      position: relative;
      overflow: hidden;
      background-image: radial-gradient(circle at 20% 40%, rgba(230,57,70,0.08) 0%, transparent 45%);
    }
    .hero-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 48px;
      align-items: center;
    }
    .hero-left h1 {
      font-size: 3.5rem;
      line-height: 4rem;
      font-weight: 700;
      letter-spacing: -0.03em;
      margin-bottom: 1.5rem;
      color: white;
    }
    .hero-left .subtitle {
      font-size: 1.25rem;
      color: var(--color-text-gray);
      margin-bottom: 2rem;
      max-width: 85%;
    }
    .hero-cta-group {
      display: flex;
      gap: 16px;
      margin-bottom: 2rem;
      flex-wrap: wrap;
    }
    .hero-stats {
      font-size: 0.95rem;
      color: var(--color-text-muted-dark);
    }
    .hero-stats strong {
      font-family: var(--font-mono);
      color: var(--color-accent);
      font-size: 1.2rem;
    }
    .hero-right {
      position: relative;
      display: flex;
      justify-content: center;
      align-items: center;
    }
    .hero-mockup {
      max-width: 320px;
      transform: rotate(-2deg);
      border-radius: 24px;
      box-shadow: 0 25px 50px -12px rgba(0,0,0,0.8);
      background: #1A1F2B;
      transition: transform 0.3s ease;
    }
    .hero-mockup:hover {
      transform: rotate(0deg) scale(1.02);
    }

    /* 优势网格 */
    .features-section {
      background: var(--color-bg-dark);
    }
    .features-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
      margin-top: 48px;
    }
    .feature-card {
      background: transparent;
      border: 1px solid var(--color-border-dark);
      padding: 32px;
      border-radius: var(--radius-card);
      transition: var(--transition-smooth);
      position: relative;
      color: white;
    }
    .feature-card:hover {
      border-color: rgba(230,57,70,0.3);
      box-shadow: var(--shadow-dark-card-hover);
      transform: translateY(-4px);
    }
    .feature-icon {
      color: var(--color-accent);
      font-size: 1.8rem;
      margin-bottom: 1.2rem;
    }
    .feature-card h3 {
      font-size: 1.25rem;
      font-weight: 600;
      margin-bottom: 0.8rem;
    }
    .feature-card p {
      color: var(--color-text-gray);
      font-size: 0.95rem;
      line-height: 1.6;
    }
    .feature-line {
      width: 24px;
      height: 2px;
      background: var(--color-accent);
      margin-top: 1.5rem;
      transition: width 0.2s ease;
    }
    .feature-card:hover .feature-line {
      width: 100%;
    }

    /* 案例瀑布 */
    .cases-section {
      background: var(--color-bg-light);
      color: var(--color-text-dark);
    }
    .cases-section .section-title {
      color: var(--color-text-dark);
    }
    .waterfall {
      columns: 2;
      column-gap: 24px;
      margin-top: 48px;
    }
    .case-card {
      break-inside: avoid;
      background: white;
      border-radius: var(--radius-card);
      box-shadow: var(--shadow-light-card);
      margin-bottom: 24px;
      overflow: hidden;
      transition: var(--transition-smooth);
    }
    .case-card:hover {
      box-shadow: var(--shadow-light-card-hover);
      transform: translateY(-4px);
    }
    .case-card img {
      width: 100%;
      display: block;
      background: #E5E7EB;
    }
    .case-body {
      padding: 20px;
    }
    .case-tag {
      font-size: 0.8rem;
      font-weight: 500;
      text-transform: uppercase;
      color: var(--color-accent);
      margin-bottom: 0.5rem;
      letter-spacing: 0.5px;
    }
    .case-body h3 {
      font-size: 1.25rem;
      font-weight: 600;
      margin-bottom: 0.5rem;
    }
    .case-body p {
      color: var(--color-text-light-gray);
      font-size: 0.9rem;
      margin-bottom: 1rem;
    }
    .case-meta {
      display: flex;
      gap: 16px;
      font-size: 0.8rem;
      color: var(--color-text-muted-light);
    }

    /* 对比表 */
    .comparison-section {
      background: var(--color-bg-dark);
    }
    .comparison-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 0;
      margin-top: 48px;
      border: 1px solid var(--color-border-dark);
      border-radius: var(--radius-container);
      overflow: hidden;
    }
    .plan {
      padding: 48px;
      display: flex;
      flex-direction: column;
    }
    .plan-free {
      background: #0F131C;
    }
    .plan-pro {
      background: #141A24;
      border-left: 1px solid var(--color-border-dark);
      box-shadow: inset 0 0 0 1px rgba(230,57,70,0.15);
    }
    .plan h3 {
      font-size: 1.5rem;
      margin-bottom: 1.5rem;
    }
    .plan ul {
      list-style: none;
      margin-bottom: 2rem;
      flex: 1;
    }
    .plan li {
      margin-bottom: 1rem;
      display: flex;
      align-items: center;
      gap: 12px;
      color: var(--color-text-gray);
    }
    .plan li i {
      color: var(--color-data-green);
      font-size: 1.1rem;
    }
    .plan-pro li i {
      color: var(--color-accent);
    }
    .btn-block {
      width: 100%;
      margin-top: auto;
    }

    /* FAQ */
    .faq-section {
      background: var(--color-bg-light);
      color: var(--color-text-dark);
    }
    .faq-list {
      max-width: 800px;
      margin: 48px auto 0;
      display: flex;
      flex-direction: column;
      gap: 16px;
    }
    .faq-item {
      background: white;
      border: 1px solid var(--color-border-light);
      border-radius: var(--radius-card);
      padding: 20px 24px;
      cursor: pointer;
      transition: var(--transition-smooth);
    }
    .faq-item.active {
      border-left: 4px solid var(--color-accent);
    }
    .faq-question {
      display: flex;
      justify-content: space-between;
      align-items: center;
      font-weight: 600;
      font-size: 1.05rem;
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.3s ease;
      color: var(--color-text-light-gray);
      margin-top: 0;
    }
    .faq-item.active .faq-answer {
      max-height: 150px;
      margin-top: 12px;
    }

    /* CTA 横幅 */
    .cta-banner {
      background: var(--color-bg-dark);
      text-align: center;
      padding: 80px 24px;
    }

    /* 页脚 */
    .footer {
      background: #05070A;
      padding: 60px 0 100px;
      border-top: 1px solid var(--color-border-dark);
    }
    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1fr;
      gap: 32px;
    }
    .footer-col p {
      color: var(--color-text-gray);
      font-size: 0.9rem;
      margin-top: 12px;
    }
    .footer-col h4 {
      margin-bottom: 16px;
      color: white;
    }
    .footer-col a {
      display: block;
      color: var(--color-text-gray);
      margin-bottom: 10px;
      font-size: 0.9rem;
    }
    .copyright {
      margin-top: 48px;
      text-align: center;
      color: var(--color-text-muted-dark);
      font-size: 0.8rem;
    }

    /* 响应式 */
    @media (max-width: 1023px) {
      .nav-links { display: none; }
      .nav-mobile-bottom { display: flex; }
      .nav-pc { justify-content: center; height: 64px; }
      .hero-grid { grid-template-columns: 1fr; }
      .hero-right { order: -1; }
      .hero-left h1 { font-size: 2.6rem; line-height: 3rem; }
      .features-grid { grid-template-columns: 1fr 1fr; }
      .waterfall { columns: 1; }
      .comparison-grid { grid-template-columns: 1fr; }
      .plan-pro { border-left: none; border-top: 1px solid var(--color-border-dark); }
    }

    @media (max-width: 767px) {
      .container { padding: 0 20px; }
      section { padding-top: var(--spacing-section-mobile); padding-bottom: var(--spacing-section-mobile); }
      .section-title { font-size: 2rem; }
      .features-grid { grid-template-columns: 1fr; }
      .hero-left h1 { font-size: 2.2rem; line-height: 2.6rem; }
      .footer-grid { grid-template-columns: 1fr 1fr; }
      .btn { padding: 14px 28px; }
      .hero-cta-group { flex-direction: column; align-items: flex-start; }
    }