/* roulang page: index */
:root {
      --primary: #0A2E1F;
      --accent: #00E5A1;
      --gold: #F5B642;
      --bg-light: #F7F9F8;
      --text-dark: #1A1A1A;
      --text-muted: #5A5A5A;
      --white: #FFFFFF;
      --card-bg: rgba(255,255,255,0.75);
      --card-border: rgba(255,255,255,0.4);
      --shadow-card: 0 8px 32px rgba(0,0,0,0.06);
      --radius-lg: 20px;
      --radius-sm: 12px;
      --radius-pill: 50px;
      --font-sans: "PingFang SC", "Microsoft YaHei", "Helvetica Neue", system-ui, -apple-system, sans-serif;
      --transition: all 0.25s ease;
    }

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

    html {
      scroll-behavior: smooth;
      scroll-padding-top: 80px;
    }

    body {
      font-family: var(--font-sans);
      background-color: var(--bg-light);
      color: var(--text-dark);
      line-height: 1.75;
      font-size: 1rem;
      -webkit-font-smoothing: antialiased;
      overflow-x: hidden;
    }

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

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

    button, .btn {
      cursor: pointer;
      font-family: inherit;
      border: none;
      outline: none;
      transition: var(--transition);
      display: inline-flex;
      align-items: center;
      justify-content: center;
      gap: 0.5rem;
      font-weight: 700;
    }

    .container {
      max-width: 1280px;
      margin-left: auto;
      margin-right: auto;
      padding-left: 2rem;
      padding-right: 2rem;
    }

    /* 导航 */
    .nav {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      z-index: 1000;
      height: 72px;
      display: flex;
      align-items: center;
      background: transparent;
      transition: background 0.3s ease, backdrop-filter 0.3s ease;
    }

    .nav.scrolled {
      background: rgba(10,46,31,0.88);
      backdrop-filter: blur(16px);
      box-shadow: 0 4px 20px rgba(0,0,0,0.15);
    }

    .nav-container {
      display: flex;
      align-items: center;
      justify-content: space-between;
      width: 100%;
    }

    .logo {
      display: flex;
      align-items: center;
      gap: 0.5rem;
      font-weight: 800;
      font-size: 1.5rem;
      color: var(--white);
      letter-spacing: -0.02em;
    }

    .logo-icon {
      width: 32px;
      height: 32px;
      background: var(--accent);
      border-radius: 50%;
      display: flex;
      align-items: center;
      justify-content: center;
      color: var(--primary);
      font-weight: 700;
      font-size: 1.2rem;
    }

    .nav-links {
      display: flex;
      align-items: center;
      gap: 2rem;
    }

    .nav-links a {
      color: rgba(255,255,255,0.85);
      font-weight: 500;
      font-size: 0.95rem;
      position: relative;
      padding-bottom: 4px;
    }

    .nav-links a:hover,
    .nav-links a.active {
      color: var(--accent);
    }

    .nav-links a::after {
      content: '';
      position: absolute;
      bottom: 0;
      left: 0;
      width: 0%;
      height: 2px;
      background: var(--accent);
      transition: 0.25s;
    }

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

    .btn-nav {
      background: var(--accent);
      color: var(--primary);
      padding: 10px 24px;
      border-radius: var(--radius-pill);
      font-weight: 700;
      font-size: 0.9rem;
      box-shadow: 0 4px 12px rgba(0,229,161,0.3);
    }

    .btn-nav:hover {
      background: #00C98A;
      box-shadow: 0 0 20px rgba(0,229,161,0.6);
      transform: translateY(-2px);
    }

    .hamburger {
      display: none;
      flex-direction: column;
      gap: 5px;
      cursor: pointer;
      background: none;
      border: none;
    }

    .hamburger span {
      width: 26px;
      height: 3px;
      background: var(--white);
      border-radius: 3px;
      transition: var(--transition);
    }

    .mobile-menu {
      position: fixed;
      top: 0;
      right: 0;
      width: 80%;
      max-width: 320px;
      height: 100vh;
      background: rgba(10,46,31,0.95);
      backdrop-filter: blur(20px);
      flex-direction: column;
      padding: 2rem;
      gap: 2rem;
      transform: translateX(100%);
      transition: transform 0.3s ease;
      z-index: 999;
      display: flex;
      align-items: flex-start;
      justify-content: center;
    }

    .mobile-menu.active {
      transform: translateX(0);
    }

    .mobile-menu a {
      color: var(--white);
      font-size: 1.3rem;
      font-weight: 600;
      border-bottom: 1px solid rgba(255,255,255,0.2);
      width: 100%;
      padding-bottom: 1rem;
    }

    /* 板块通用 */
    section {
      padding: 5rem 0;
    }

    .section-title {
      text-align: center;
      margin-bottom: 3rem;
    }

    .section-title h2 {
      font-size: clamp(2rem, 4vw, 2.8rem);
      font-weight: 700;
      color: var(--primary);
      margin-bottom: 1rem;
    }

    .section-title p {
      color: var(--text-muted);
      max-width: 600px;
      margin: 0 auto;
    }

    /* Hero */
    .hero {
      padding: 140px 0 100px;
      background: linear-gradient(135deg, #0A2E1F 0%, #0D3B2A 100%);
      position: relative;
      overflow: hidden;
      color: var(--white);
    }

    .hero::before {
      content: '';
      position: absolute;
      width: 500px;
      height: 500px;
      background: radial-gradient(circle, rgba(0,229,161,0.25) 0%, transparent 70%);
      top: -100px;
      right: -100px;
      border-radius: 50%;
      filter: blur(80px);
    }

    .hero-watermark {
      position: absolute;
      right: 5%;
      top: 20%;
      width: 300px;
      height: 300px;
      background: url('data:image/svg+xml;utf8,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 100 100"><path d="M50 20 C35 20 25 35 25 50 C25 70 40 80 50 80 C60 80 75 70 75 50 C75 35 65 20 50 20z" fill="white" opacity="0.08"/><circle cx="40" cy="45" r="8" fill="white" opacity="0.08"/><circle cx="60" cy="45" r="8" fill="white" opacity="0.08"/></svg>') no-repeat center;
      background-size: contain;
      opacity: 0.08;
      pointer-events: none;
    }

    .hero-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 3rem;
      align-items: center;
      position: relative;
      z-index: 2;
    }

    .hero-content h1 {
      font-size: clamp(2.5rem, 6vw, 4rem);
      font-weight: 800;
      letter-spacing: -0.02em;
      line-height: 1.2;
      margin-bottom: 1.5rem;
    }

    .hero-content .highlight {
      color: var(--accent);
    }

    .hero-content p {
      font-size: 1.15rem;
      opacity: 0.9;
      margin-bottom: 2rem;
      max-width: 500px;
    }

    .hero-buttons {
      display: flex;
      gap: 1rem;
      flex-wrap: wrap;
    }

    .btn-primary {
      background: var(--accent);
      color: var(--primary);
      padding: 14px 36px;
      border-radius: var(--radius-pill);
      font-weight: 700;
      box-shadow: 0 4px 14px rgba(0,229,161,0.3);
    }

    .btn-primary:hover {
      background: #00C98A;
      box-shadow: 0 0 24px rgba(0,229,161,0.6);
      transform: translateY(-2px);
    }

    .btn-outline {
      background: transparent;
      border: 2px solid var(--accent);
      color: var(--accent);
      padding: 14px 36px;
      border-radius: var(--radius-pill);
      font-weight: 700;
    }

    .btn-outline:hover {
      background: var(--accent);
      color: var(--primary);
    }

    .hero-image {
      background: rgba(255,255,255,0.05);
      border-radius: 24px;
      overflow: hidden;
      border: 1px solid rgba(255,255,255,0.15);
      backdrop-filter: blur(4px);
      animation: float 6s infinite ease-in-out;
    }

    @keyframes float {
      0% { transform: translateY(0px); }
      50% { transform: translateY(-12px); }
      100% { transform: translateY(0px); }
    }

    /* 核心优势 */
    .features-grid {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 24px;
    }

    .feature-card {
      background: var(--card-bg);
      backdrop-filter: blur(12px);
      border: 1px solid var(--card-border);
      border-radius: var(--radius-lg);
      padding: 2rem 1.5rem;
      box-shadow: var(--shadow-card);
      transition: var(--transition);
      text-align: center;
    }

    .feature-card:hover {
      transform: translateY(-8px);
      box-shadow: 0 16px 40px rgba(0,0,0,0.1);
      border-color: var(--accent);
    }

    .feature-icon {
      width: 60px;
      height: 60px;
      background: var(--accent);
      border-radius: 50%;
      display: flex;
      align-items: center;
      justify-content: center;
      margin: 0 auto 1.25rem;
      font-size: 1.8rem;
      color: var(--primary);
    }

    .feature-card h3 {
      font-size: 1.4rem;
      margin-bottom: 0.75rem;
      color: var(--primary);
    }

    /* 数据背书 */
    .stats {
      background: var(--primary);
      color: var(--white);
    }

    .stats-grid {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 2rem;
      text-align: center;
    }

    .stat-number {
      font-size: 3rem;
      font-weight: 800;
      color: var(--accent);
      font-feature-settings: "tnum";
    }

    .stat-label {
      color: rgba(255,255,255,0.7);
      margin-top: 0.5rem;
    }

    /* 案例 */
    .cases-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
    }

    .case-card {
      background: var(--white);
      border-radius: var(--radius-lg);
      overflow: hidden;
      box-shadow: var(--shadow-card);
      transition: var(--transition);
    }

    .case-card:hover {
      transform: translateY(-6px);
      box-shadow: 0 20px 30px rgba(0,0,0,0.08);
    }

    .case-img {
      height: 200px;
      background: #e0e8e4;
      overflow: hidden;
    }

    .case-img img {
      width: 100%;
      height: 100%;
      object-fit: cover;
      transition: 0.4s;
    }

    .case-card:hover .case-img img {
      transform: scale(1.05);
    }

    .case-content {
      padding: 1.5rem;
    }

    .case-tag {
      background: var(--gold);
      color: #1A1A1A;
      padding: 4px 14px;
      border-radius: 20px;
      font-size: 0.75rem;
      font-weight: 700;
      display: inline-block;
      margin-bottom: 0.75rem;
    }

    /* 解决方案 */
    .solution-row {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 3rem;
      align-items: center;
    }

    .solution-list {
      list-style: none;
      display: flex;
      flex-direction: column;
      gap: 2rem;
    }

    .solution-item {
      display: flex;
      gap: 1rem;
    }

    .solution-icon {
      font-size: 1.8rem;
      color: var(--accent);
    }

    /* FAQ */
    .faq-grid {
      display: grid;
      grid-template-columns: 1fr 2fr;
      gap: 3rem;
    }

    .accordion-item {
      border-bottom: 1px solid #ddd;
      padding: 1.25rem 0;
      cursor: pointer;
    }

    .accordion-title {
      font-weight: 700;
      display: flex;
      justify-content: space-between;
      align-items: center;
      color: var(--primary);
    }

    .accordion-content {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.3s ease;
      color: var(--text-muted);
    }

    .accordion-item.active .accordion-content {
      max-height: 200px;
      margin-top: 1rem;
    }

    /* CTA */
    .cta {
      background: var(--primary);
      text-align: center;
      color: white;
      padding: 5rem 0;
    }

    .cta h2 {
      font-size: 2.5rem;
      margin-bottom: 1rem;
    }

    .footer-bottom {
      text-align: center;
      padding: 2rem;
      color: rgba(255,255,255,0.6);
      font-size: 0.9rem;
    }

    @media (max-width: 1024px) {
      .features-grid { grid-template-columns: repeat(2,1fr); }
      .cases-grid { grid-template-columns: 1fr 1fr; }
    }

    @media (max-width: 768px) {
      .nav-links { display: none; }
      .hamburger { display: flex; }
      .hero-grid, .solution-row, .faq-grid { grid-template-columns: 1fr; }
      .features-grid, .stats-grid { grid-template-columns: 1fr; }
      .cases-grid { grid-template-columns: 1fr; }
      section { padding: 3rem 0; }
      .container { padding: 0 1.25rem; }
    }