/* roulang page: index */
:root {
      --primary: #FF4D00;
      --primary-dark: #E04400;
      --secondary-bg: #0A0E17;
      --card-bg: #1F2836;
      --accent-gold: #FFD700;
      --light-gray: #F2F4F8;
      --text-gray: #8A94A6;
      --text-dark: #4A5568;
      --white: #FFFFFF;
      --border-radius-card: 20px;
      --border-radius-btn: 50px;
      --shadow-card: 0 10px 30px -10px rgba(0,0,0,0.5);
      --shadow-hover: 0 20px 35px -10px rgba(255,77,0,0.3);
      --transition-smooth: all 0.3s cubic-bezier(0.25, 0.8, 0.25, 1);
      --font-inter: 'Inter', sans-serif;
      --font-noto: 'Noto Sans SC', sans-serif;
    }

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

    html {
      scroll-behavior: smooth;
    }

    body {
      font-family: var(--font-noto);
      background-color: var(--secondary-bg);
      color: var(--white);
      line-height: 1.6;
      -webkit-font-smoothing: antialiased;
      overflow-x: hidden;
    }

    .container {
      max-width: 1280px;
      margin: 0 auto;
      padding: 0 24px;
    }

    /* 导航 */
    .header {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      z-index: 1000;
      background: rgba(10, 14, 23, 0.85);
      backdrop-filter: blur(15px);
      -webkit-backdrop-filter: blur(15px);
      border-bottom: 1px solid rgba(255,255,255,0.05);
      transition: background 0.3s ease;
    }
    .nav {
      display: flex;
      justify-content: space-between;
      align-items: center;
      padding: 16px 24px;
      max-width: 1280px;
      margin: 0 auto;
    }
    .logo {
      font-size: 1.8rem;
      font-weight: 700;
      color: var(--white);
      letter-spacing: -0.5px;
      text-decoration: none;
      display: flex;
      align-items: center;
      gap: 8px;
    }
    .logo span {
      color: var(--primary);
    }
    .nav-links {
      display: flex;
      gap: 32px;
      align-items: center;
    }
    .nav-links a {
      color: var(--text-gray);
      text-decoration: none;
      font-weight: 500;
      font-size: 1rem;
      transition: color 0.2s;
      position: relative;
      padding-bottom: 6px;
    }
    .nav-links a:hover,
    .nav-links a.active {
      color: var(--primary);
    }
    .nav-links a::after {
      content: '';
      position: absolute;
      bottom: 0;
      left: 0;
      width: 0;
      height: 2px;
      background: var(--primary);
      transition: width 0.3s ease;
    }
    .nav-links a:hover::after,
    .nav-links a.active::after {
      width: 100%;
    }
    .hamburger {
      display: none;
      flex-direction: column;
      cursor: pointer;
      gap: 6px;
      background: transparent;
      border: none;
      padding: 8px;
      z-index: 1001;
    }
    .hamburger span {
      width: 28px;
      height: 3px;
      background: var(--white);
      border-radius: 4px;
      transition: 0.3s;
      display: block;
    }
    .mobile-menu {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      height: 100vh;
      background: var(--secondary-bg);
      display: flex;
      flex-direction: column;
      justify-content: center;
      align-items: center;
      gap: 40px;
      font-size: 1.8rem;
      transform: translateY(-100%);
      opacity: 0;
      transition: 0.4s ease;
      z-index: 999;
      backdrop-filter: blur(20px);
    }
    .mobile-menu.active {
      transform: translateY(0);
      opacity: 1;
    }
    .mobile-menu a {
      color: var(--white);
      text-decoration: none;
      font-weight: 600;
    }
    /* 板块通用 */
    section {
      padding: 80px 0;
      position: relative;
    }
    .section-title {
      font-size: 2.5rem;
      font-weight: 700;
      margin-bottom: 16px;
      display: inline-block;
      position: relative;
    }
    .section-title::after {
      content: '';
      display: block;
      width: 50px;
      height: 4px;
      background: var(--primary);
      margin-top: 12px;
      border-radius: 2px;
    }
    .dark-bg {
      background-color: var(--secondary-bg);
    }
    .light-bg {
      background-color: var(--light-gray);
      color: var(--secondary-bg);
    }
    .light-bg .section-title {
      color: var(--secondary-bg);
    }
    .light-bg .section-title::after {
      background: var(--primary);
    }
    .grid-3 {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
      margin-top: 40px;
    }
    .card {
      background: var(--card-bg);
      border-radius: var(--border-radius-card);
      padding: 32px;
      transition: var(--transition-smooth);
      border: 2px solid transparent;
      box-shadow: var(--shadow-card);
      backdrop-filter: blur(10px);
      position: relative;
      overflow: hidden;
    }
    .card:hover {
      transform: translateY(-6px);
      box-shadow: var(--shadow-hover);
      border-top: 2px solid var(--primary);
    }
    .light-bg .card {
      background: var(--white);
      color: var(--secondary-bg);
      box-shadow: 0 10px 25px -8px rgba(0,0,0,0.1);
    }
    .badge-gold {
      background: var(--accent-gold);
      color: var(--secondary-bg);
      font-weight: 700;
      font-size: 0.8rem;
      padding: 6px 14px;
      border-radius: 30px;
      display: inline-block;
      letter-spacing: 0.3px;
    }
    .btn {
      display: inline-block;
      padding: 14px 32px;
      border-radius: var(--border-radius-btn);
      font-weight: 600;
      text-decoration: none;
      transition: var(--transition-smooth);
      cursor: pointer;
      border: none;
      font-family: var(--font-noto);
    }
    .btn-primary {
      background: var(--primary);
      color: white;
      box-shadow: 0 6px 18px rgba(255,77,0,0.3);
    }
    .btn-primary:hover {
      background: var(--primary-dark);
      box-shadow: 0 10px 25px rgba(255,77,0,0.5);
      transform: translateY(-2px);
    }
    .btn-outline {
      background: transparent;
      border: 2px solid var(--white);
      color: var(--white);
    }
    .btn-outline:hover {
      background: var(--white);
      color: var(--secondary-bg);
    }
    .light-bg .btn-outline {
      border-color: var(--primary);
      color: var(--primary);
    }
    .light-bg .btn-outline:hover {
      background: var(--primary);
      color: white;
    }
    /* Hero */
    .hero {
      min-height: 100vh;
      display: flex;
      align-items: center;
      background-image: url('/assets/images/backpic/back-1.webp');
      background-size: cover;
      background-position: center;
      position: relative;
      padding-top: 80px;
    }
    .hero-overlay {
      position: absolute;
      top:0;left:0;width:100%;height:100%;
      background: radial-gradient(circle at 20% 50%, rgba(10,14,23,0.7) 0%, #0A0E17 90%);
    }
    .hero-content {
      display: flex;
      align-items: center;
      gap: 40px;
      position: relative;
      z-index: 2;
    }
    .hero-left {
      flex: 1.2;
    }
    .hero-right {
      flex: 1;
      display: flex;
      justify-content: center;
    }
    .hero h1 {
      font-size: 3.8rem;
      font-weight: 800;
      line-height: 1.2;
      margin-bottom: 24px;
    }
    .hero .subtitle {
      font-size: 1.4rem;
      color: var(--text-gray);
      margin-bottom: 36px;
    }
    .floating-badge {
      background: var(--accent-gold);
      color: #000;
      font-weight: 700;
      padding: 8px 20px;
      border-radius: 40px;
    }
    /* 痛点 */
    .pain-icon {
      color: #c0392b;
      font-size: 2rem;
      margin-bottom: 12px;
    }
    /* 解决方案数据徽章 */
    .metric-badge {
      position: absolute;
      top: 16px;
      right: 16px;
    }
    /* 成果数字 */
    .stat-number {
      font-size: 3rem;
      font-weight: 800;
      color: var(--accent-gold);
      font-family: var(--font-inter);
    }
    /* 客户证言 */
    .testimonial-card {
      background: var(--card-bg);
      border-radius: 20px;
      padding: 28px;
      border-left: 4px solid;
      border-image: linear-gradient(to bottom, var(--primary), var(--accent-gold)) 1;
    }
    /* FAQ */
    .faq-item {
      background: var(--card-bg);
      border-radius: 16px;
      margin-bottom: 16px;
      padding: 18px 24px;
      cursor: pointer;
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.4s ease;
    }
    /* 页脚 */
    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1.5fr;
      gap: 30px;
    }
    @media (max-width: 768px) {
      .nav-links { display: none; }
      .hamburger { display: flex; }
      .grid-3, .footer-grid { grid-template-columns: 1fr; }
      .hero-content { flex-direction: column; text-align: center; }
      .hero h1 { font-size: 2.4rem; }
      .section-title { font-size: 2rem; }
    }