/* roulang page: index */
:root {
      --primary-dark: #0A0E17;
      --accent-red: #E63946;
      --accent-red-hover: #C1121F;
      --accent-orange: #F4A261;
      --bg-light: #F8F9FA;
      --white: #FFFFFF;
      --text-primary: #1A1A1A;
      --text-secondary: #6B7280;
      --text-light: #E5E7EB;
      --border-light: #E5E7EB;
      --shadow-card: 0 1px 3px rgba(0,0,0,0.04), 0 1px 2px rgba(0,0,0,0.06);
      --shadow-card-hover: 0 10px 25px rgba(0,0,0,0.08);
      --shadow-button-glow: 0 0 0 4px rgba(230,57,70,0.2);
      --radius-card: 12px;
      --radius-button: 8px;
      --radius-tag: 6px;
      --font-title: 'DM Sans', 'Inter', sans-serif;
      --font-body: 'Noto Sans SC', 'Inter', sans-serif;
      --font-mono: 'DM Mono', monospace;
      --container-max: 1280px;
      --section-gap-desktop: 120px;
      --section-gap-tablet: 80px;
      --section-gap-mobile: 60px;
      --transition-smooth: 0.3s ease;
    }
    * {
      margin: 0;
      padding: 0;
      box-sizing: border-box;
    }
    html {
      scroll-behavior: smooth;
    }
    body {
      font-family: var(--font-body);
      background-color: var(--bg-light);
      color: var(--text-primary);
      line-height: 1.7;
      font-size: 16px;
      -webkit-font-smoothing: antialiased;
      overflow-x: hidden;
    }
    .container {
      max-width: var(--container-max);
      margin: 0 auto;
      padding: 0 32px;
    }
    @media (max-width: 1024px) {
      .container {
        padding: 0 24px;
      }
    }
    @media (max-width: 640px) {
      .container {
        padding: 0 20px;
      }
    }
    h1, h2, h3, h4 {
      font-family: var(--font-title);
      font-weight: 700;
    }
    h1 {
      font-size: 56px;
      line-height: 1.1;
      font-weight: 900;
      letter-spacing: -0.02em;
    }
    h2 {
      font-size: 40px;
      line-height: 1.2;
      font-weight: 700;
    }
    h3 {
      font-size: 24px;
      line-height: 1.3;
      font-weight: 600;
    }
    p {
      color: var(--text-secondary);
    }
    a {
      text-decoration: none;
      color: inherit;
    }
    img {
      max-width: 100%;
      display: block;
    }
    button, .btn {
      cursor: pointer;
      font-family: var(--font-title);
      font-weight: 700;
      display: inline-flex;
      align-items: center;
      justify-content: center;
      border: none;
      transition: var(--transition-smooth);
    }
    /* 导航 */
    .navbar {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      z-index: 1000;
      padding: 16px 0;
      transition: background 0.3s, box-shadow 0.3s, backdrop-filter 0.3s;
      background: transparent;
    }
    .navbar.scrolled {
      background: rgba(255,255,255,0.95);
      backdrop-filter: blur(12px);
      box-shadow: 0 1px 4px rgba(0,0,0,0.04);
      border-bottom: 1px solid var(--border-light);
    }
    .navbar .container {
      display: flex;
      align-items: center;
      justify-content: space-between;
    }
    .logo {
      font-family: var(--font-title);
      font-weight: 900;
      font-size: 24px;
      letter-spacing: -0.5px;
      color: white;
      transition: color 0.3s;
    }
    .navbar.scrolled .logo {
      color: var(--primary-dark);
    }
    .nav-links {
      display: flex;
      align-items: center;
      gap: 32px;
      list-style: none;
    }
    .nav-links a {
      font-weight: 600;
      font-size: 16px;
      color: rgba(255,255,255,0.9);
      transition: color 0.3s;
    }
    .navbar.scrolled .nav-links a {
      color: var(--text-primary);
    }
    .nav-links a:hover {
      color: var(--accent-red);
    }
    .nav-cta {
      background: var(--accent-red);
      color: white !important;
      padding: 12px 24px;
      border-radius: var(--radius-button);
      font-weight: 700;
      transition: background 0.3s, box-shadow 0.3s;
    }
    .nav-cta:hover {
      background: var(--accent-red-hover);
      box-shadow: var(--shadow-button-glow);
    }
    .hamburger {
      display: none;
      flex-direction: column;
      gap: 5px;
      background: transparent;
      border: none;
      cursor: pointer;
    }
    .hamburger span {
      width: 24px;
      height: 2px;
      background: white;
      transition: 0.3s;
    }
    .navbar.scrolled .hamburger span {
      background: var(--primary-dark);
    }
    .mobile-menu {
      display: none;
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      height: 100vh;
      background: rgba(10,14,23,0.98);
      backdrop-filter: blur(20px);
      flex-direction: column;
      align-items: center;
      justify-content: center;
      gap: 40px;
      z-index: 999;
      opacity: 0;
      pointer-events: none;
      transition: opacity 0.3s;
    }
    .mobile-menu.active {
      opacity: 1;
      pointer-events: auto;
    }
    .mobile-menu a {
      font-size: 28px;
      color: white;
      font-weight: 600;
    }
    @media (max-width: 768px) {
      .nav-links {
        display: none;
      }
      .hamburger {
        display: flex;
      }
      .mobile-menu {
        display: flex;
      }
    }
    /* 按钮全局 */
    .btn-primary {
      background: var(--accent-red);
      color: white;
      border-radius: var(--radius-button);
      padding: 16px 32px;
      font-weight: 700;
      font-size: 16px;
    }
    .btn-primary:hover {
      background: var(--accent-red-hover);
      box-shadow: var(--shadow-button-glow);
    }
    .btn-secondary {
      background: transparent;
      color: var(--primary-dark);
      border: 2px solid var(--primary-dark);
      border-radius: var(--radius-button);
      padding: 16px 32px;
      font-weight: 700;
    }
    .btn-secondary:hover {
      background: var(--primary-dark);
      color: white;
    }
    .btn-large {
      padding: 20px 40px;
      font-size: 18px;
    }
    /* 区块动画 */
    .fade-up {
      opacity: 0;
      transform: translateY(30px);
      transition: opacity 0.6s ease-out, transform 0.6s ease-out;
    }
    .fade-up.visible {
      opacity: 1;
      transform: translateY(0);
    }
    /* Hero */
    .hero {
      background: linear-gradient(135deg, #0A0E17 0%, #141B26 100%);
      min-height: 100vh;
      display: flex;
      align-items: center;
      color: white;
      position: relative;
      overflow: hidden;
    }
    .hero .container {
      display: flex;
      align-items: center;
      gap: 60px;
      width: 100%;
      padding-top: 80px;
    }
    .hero-left {
      flex: 1;
    }
    .hero-left h1 {
      color: white;
      margin-bottom: 24px;
    }
    .hero-left p {
      color: var(--text-light);
      font-size: 18px;
      margin-bottom: 40px;
    }
    .hero-buttons {
      display: flex;
      gap: 16px;
      flex-wrap: wrap;
    }
    .hero-right {
      flex: 1;
      display: flex;
      justify-content: center;
    }
    .hero-right img {
      max-height: 500px;
      border-radius: 24px;
      transform: rotate(1deg);
      box-shadow: 0 20px 40px rgba(0,0,0,0.5);
    }
    @media (max-width: 1024px) {
      .hero .container {
        flex-direction: column;
        text-align: center;
        padding-top: 100px;
        gap: 40px;
      }
      .hero-buttons {
        justify-content: center;
      }
      h1 {
        font-size: 48px;
      }
    }
    @media (max-width: 640px) {
      h1 {
        font-size: 36px;
      }
      .hero-right img {
        max-height: 300px;
      }
    }
    /* 通用区块 */
    section {
      padding: var(--section-gap-desktop) 0;
    }
    @media (max-width: 1024px) {
      section {
        padding: var(--section-gap-tablet) 0;
      }
    }
    @media (max-width: 640px) {
      section {
        padding: var(--section-gap-mobile) 0;
      }
    }
    .section-title {
      margin-bottom: 48px;
    }
    .section-title h2 {
      margin-bottom: 12px;
    }
    /* 痛点 */
    .pain-grid {
      display: grid;
      grid-template-columns: 1.2fr 0.8fr;
      gap: 32px;
    }
    .pain-card {
      background: white;
      border-radius: var(--radius-card);
      padding: 32px;
      box-shadow: var(--shadow-card);
    }
    .pain-card.large img {
      width: 100%;
      border-radius: 8px;
      margin-top: 20px;
    }
    .pain-card h3 {
      margin-bottom: 12px;
    }
    .pain-stack {
      display: flex;
      flex-direction: column;
      gap: 24px;
    }
    .pain-item {
      background: white;
      padding: 24px;
      border-radius: var(--radius-card);
      box-shadow: var(--shadow-card);
    }
    @media (max-width: 768px) {
      .pain-grid {
        grid-template-columns: 1fr;
      }
    }
    /* 解决方案 1+2 */
    .solutions-layout {
      display: flex;
      flex-direction: column;
      gap: 32px;
    }
    .solution-wide {
      background: white;
      border-radius: var(--radius-card);
      padding: 40px;
      border-top: 4px solid var(--accent-red);
      box-shadow: var(--shadow-card);
    }
    .solution-cards {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 32px;
    }
    .solution-card {
      background: white;
      border-radius: var(--radius-card);
      padding: 32px;
      box-shadow: var(--shadow-card);
      position: relative;
    }
    .solution-card img {
      width: 80px;
      height: 80px;
      border-radius: 50%;
      object-fit: cover;
      margin-bottom: 20px;
    }
    @media (max-width: 640px) {
      .solution-cards {
        grid-template-columns: 1fr;
      }
    }
    /* 成果深色区 */
    .results {
      background: var(--primary-dark);
      color: white;
    }
    .stats-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 48px;
      text-align: center;
    }
    .stat-number {
      font-family: var(--font-mono);
      font-size: 64px;
      color: var(--accent-red);
      font-weight: 500;
    }
    @media (max-width: 640px) {
      .stats-grid {
        grid-template-columns: 1fr;
      }
    }
    /* 证言错落 */
    .testimonials-masonry {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 32px;
    }
    .testimonial-card {
      background: white;
      padding: 32px;
      border-radius: var(--radius-card);
      border-left: 4px solid var(--accent-orange);
      box-shadow: var(--shadow-card);
    }
    .testimonial-card:nth-child(2) {
      margin-top: 40px;
    }
    .testimonial-card:nth-child(3) {
      margin-top: 20px;
    }
    @media (max-width: 1024px) {
      .testimonials-masonry {
        grid-template-columns: 1fr 1fr;
      }
    }
    @media (max-width: 640px) {
      .testimonials-masonry {
        grid-template-columns: 1fr;
      }
    }
    /* FAQ */
    .faq-item {
      border-bottom: 1px solid var(--border-light);
    }
    .faq-question {
      width: 100%;
      background: transparent;
      border: none;
      padding: 24px 0;
      display: flex;
      justify-content: space-between;
      align-items: center;
      font-size: 20px;
      font-weight: 600;
      text-align: left;
      cursor: pointer;
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.3s ease;
      color: var(--text-secondary);
    }
    /* CTA */
    .cta-dark {
      background: var(--primary-dark);
      text-align: center;
      color: white;
    }
    .pulse {
      animation: pulse 2s infinite;
    }
    @keyframes pulse {
      0% { box-shadow: 0 0 0 0 rgba(230,57,70,0.5); }
      70% { box-shadow: 0 0 0 20px rgba(230,57,70,0); }
      100% { box-shadow: 0 0 0 0 rgba(230,57,70,0); }
    }
    footer {
      background: var(--bg-light);
      padding: 40px 0;
      border-top: 1px solid var(--border-light);
    }
    .footer-content {
      display: flex;
      justify-content: space-between;
      align-items: center;
      flex-wrap: wrap;
    }