/* roulang page: index */
/* ----- 全局设计变量与重置 ----- */
    :root {
      --bg-deep: #0A0E1A;
      --bg-deeper: #060910;
      --accent-cyan: #00E5FF;
      --accent-purple: #B44DFF;
      --success-green: #00FFAA;
      --card-bg: rgba(15, 25, 45, 0.55);
      --card-border: rgba(0, 229, 255, 0.15);
      --card-hover-border: rgba(0, 229, 255, 0.6);
      --text-primary: #FFFFFF;
      --text-body: #B0C4DE;
      --text-muted: #6A7B98;
      --glass-blur: blur(12px);
      --border-radius-lg: 16px;
      --border-radius-sm: 12px;
      --shadow-card: 0 8px 32px rgba(0, 0, 0, 0.45);
      --shadow-glow: 0 0 20px rgba(0, 229, 255, 0.25);
      --font-heading: "Inter", "PingFang SC", "Microsoft YaHei", "Helvetica Neue", sans-serif;
      --font-body: "Inter", "PingFang SC", "Microsoft YaHei", sans-serif;
      --transition-soft: all 0.3s ease;
    }

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

    html {
      scroll-behavior: smooth;
      background-color: var(--bg-deep);
    }

    body {
      font-family: var(--font-body);
      background-color: var(--bg-deep);
      color: var(--text-body);
      line-height: 1.7;
      font-weight: 400;
      overflow-x: hidden;
      position: relative;
      /* 深色网格背景纹理 (CSS生成) */
      background-image: 
        linear-gradient(rgba(0, 229, 255, 0.03) 1px, transparent 1px),
        linear-gradient(90deg, rgba(0, 229, 255, 0.02) 1px, transparent 1px);
      background-size: 40px 40px;
    }

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

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

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

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

    /* 发光装饰点与分隔线全局使用 */
    .accent-line {
      height: 2px;
      background: linear-gradient(90deg, transparent, var(--accent-cyan), var(--accent-purple), transparent);
      width: 80px;
      margin: 16px 0 24px;
    }

    .section-title {
      font-family: var(--font-heading);
      font-weight: 800;
      font-size: clamp(2rem, 5vw, 2.8rem);
      letter-spacing: -0.02em;
      color: var(--text-primary);
      margin-bottom: 12px;
    }

    .section-subtitle {
      color: var(--text-body);
      font-size: 1.125rem;
      margin-bottom: 24px;
      max-width: 700px;
    }

    /* ----- 沉浸式导航 ----- */
    .nav-container {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      background: rgba(10, 14, 26, 0.8);
      backdrop-filter: var(--glass-blur);
      -webkit-backdrop-filter: var(--glass-blur);
      border-bottom: 1px solid rgba(0, 229, 255, 0.2);
      z-index: 999;
      padding: 0 24px;
    }

    .nav-inner {
      max-width: 1280px;
      margin: 0 auto;
      display: flex;
      align-items: center;
      justify-content: space-between;
      height: 64px;
    }

    .logo {
      font-family: var(--font-heading);
      font-weight: 800;
      font-size: 1.8rem;
      letter-spacing: -0.5px;
      background: linear-gradient(135deg, #FFFFFF 0%, #00E5FF 80%);
      -webkit-background-clip: text;
      -webkit-text-fill-color: transparent;
      background-clip: text;
      display: flex;
      align-items: center;
      gap: 6px;
    }
    .logo i {
      background: none;
      -webkit-text-fill-color: var(--accent-cyan);
      font-size: 1.9rem;
    }

    .nav-links {
      display: flex;
      gap: 32px;
      align-items: center;
      list-style: none;
    }

    .nav-links a {
      color: #B0C4DE;
      font-weight: 500;
      font-size: 0.95rem;
      position: relative;
      padding: 8px 0;
    }

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

    .nav-links a::after {
      content: '';
      position: absolute;
      bottom: 0;
      left: 0;
      width: 0;
      height: 2px;
      background: var(--accent-cyan);
      box-shadow: 0 0 8px var(--accent-cyan);
      transition: width 0.25s ease;
    }

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

    .hamburger {
      display: none;
      background: transparent;
      border: none;
      color: var(--accent-cyan);
      font-size: 1.8rem;
      cursor: pointer;
    }

    @media (max-width: 768px) {
      .nav-links {
        display: none;
        position: absolute;
        top: 64px;
        left: 0;
        width: 100%;
        background: rgba(6, 9, 16, 0.96);
        backdrop-filter: blur(20px);
        flex-direction: column;
        padding: 28px;
        gap: 24px;
        border-bottom: 1px solid var(--accent-cyan);
      }
      .nav-links.open {
        display: flex;
      }
      .hamburger {
        display: block;
      }
      .nav-inner {
        height: 56px;
      }
    }

    /* ----- 首屏 Hero ----- */
    #hero {
      padding: 110px 0 80px;
      position: relative;
      background-image: url('/assets/images/backpic/back-1.webp');
      background-size: cover;
      background-position: center 30%;
      background-repeat: no-repeat;
      isolation: isolate;
    }
    #hero::before {
      content: '';
      position: absolute;
      inset: 0;
      background: radial-gradient(circle at 30% 40%, rgba(0, 229, 255, 0.15) 0%, rgba(10, 14, 26, 0.85) 70%);
      z-index: 0;
    }
    #hero .container {
      position: relative;
      z-index: 2;
      display: flex;
      align-items: center;
      gap: 48px;
      flex-wrap: wrap;
    }
    .hero-left {
      flex: 1 1 500px;
    }
    .hero-right {
      flex: 1 1 400px;
      display: flex;
      justify-content: center;
      align-items: center;
      min-height: 280px;
    }

    h1 {
      font-family: var(--font-heading);
      font-weight: 800;
      font-size: clamp(2.6rem, 6vw, 3.8rem);
      letter-spacing: -0.03em;
      line-height: 1.2;
      color: white;
      margin-bottom: 20px;
    }
    .hero-sub {
      font-size: 1.2rem;
      color: #B0C4DE;
      margin-bottom: 32px;
    }
    .btn-primary {
      background: var(--accent-cyan);
      color: #0A0E1A;
      font-weight: 700;
      padding: 14px 38px;
      border-radius: 30px;
      border: none;
      font-size: 1rem;
      letter-spacing: 0.03em;
      box-shadow: 0 0 15px rgba(0, 229, 255, 0.4);
      transition: var(--transition-soft);
      display: inline-block;
      cursor: pointer;
      text-align: center;
    }
    .btn-primary:hover {
      box-shadow: 0 0 28px rgba(0, 229, 255, 0.8);
      transform: scale(1.02);
    }
    .btn-secondary {
      background: transparent;
      border: 1px solid var(--accent-cyan);
      color: var(--accent-cyan);
      padding: 12px 34px;
      border-radius: 30px;
      font-weight: 600;
      margin-left: 16px;
      transition: var(--transition-soft);
      display: inline-block;
    }
    .btn-secondary:hover {
      background: rgba(0,229,255,0.1);
      border-color: white;
    }

    .glass-stack {
      display: flex;
      flex-direction: column;
      gap: 16px;
      transform: perspective(800px) rotateY(-4deg) rotateX(2deg);
    }
    .glass-card-sm {
      background: rgba(15, 25, 45, 0.7);
      backdrop-filter: blur(12px);
      border: 1px solid rgba(0, 229, 255, 0.3);
      border-radius: 14px;
      padding: 18px 24px;
      color: white;
      font-weight: 600;
    }

    @media (max-width: 768px) {
      #hero .container {
        flex-direction: column;
      }
      .hero-right {
        order: -1;
      }
    }

    /* 优势网格 */
    #advantages {
      padding: 80px 0;
    }
    .grid-3x2 {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 28px;
    }
    .adv-card {
      background: var(--card-bg);
      backdrop-filter: var(--glass-blur);
      border: 1px solid var(--card-border);
      border-radius: var(--border-radius-lg);
      padding: 29px 22px;
      transition: var(--transition-soft);
      box-shadow: var(--shadow-card);
    }
    .adv-card:hover {
      border-color: var(--card-hover-border);
      box-shadow: var(--shadow-glow);
      transform: translateY(-6px);
    }
    @media (max-width: 1024px) {
      .grid-3x2 { grid-template-columns: repeat(2, 1fr); }
    }
    @media (max-width: 640px) {
      .grid-3x2 { grid-template-columns: 1fr; }
    }

    /* 产品非对称瀑布 */
    #products { padding: 70px 0; }
    .product-grid {
      display: grid;
      grid-template-columns: 1.4fr 0.9fr 1.2fr;
      gap: 24px;
    }
    .prod-card {
      background: var(--card-bg);
      backdrop-filter: var(--glass-blur);
      border: 1px solid var(--card-border);
      border-radius: var(--border-radius-lg);
      overflow: hidden;
      transition: var(--transition-soft);
    }
    .prod-card:hover {
      border-color: var(--accent-cyan);
      box-shadow: var(--shadow-glow);
    }
    .prod-img { height: 180px; overflow: hidden; }
    .prod-img img { width: 100%; height: 100%; object-fit: cover; transition: transform 0.4s; }
    .prod-card:hover .prod-img img { transform: scale(1.06); }

    @media (max-width: 768px) {
      .product-grid { grid-template-columns: 1fr; }
    }

    /* 流程时间轴 */
    #process { padding: 70px 0; }
    .steps {
      display: flex;
      flex-direction: column;
      gap: 28px;
      margin-top: 30px;
    }
    .step-item {
      display: flex;
      gap: 24px;
      align-items: flex-start;
    }
    .step-num {
      font-family: 'Inter', sans-serif;
      font-weight: 800;
      font-size: 2.5rem;
      background: linear-gradient(135deg, var(--accent-cyan), var(--accent-purple));
      -webkit-background-clip: text;
      -webkit-text-fill-color: transparent;
    }

    /* 案例对比表格 */
    #cases { padding: 70px 0; }
    .compare-table {
      display: flex;
      background: rgba(10,14,26,0.7);
      backdrop-filter: blur(8px);
      border-radius: 16px;
      overflow: hidden;
      border: 1px solid rgba(0,229,255,0.2);
    }
    .col {
      flex: 1;
      padding: 28px;
    }
    .col.od {
      background: linear-gradient(145deg, rgba(0,229,255,0.12) 0%, rgba(180,77,255,0.08) 100%);
      border-left: 1px solid #00E5FF;
    }
    @media (max-width: 700px) {
      .compare-table { flex-direction: column; }
    }

    /* FAQ */
    .faq-item {
      border-bottom: 1px solid rgba(0,229,255,0.2);
      padding: 20px 0;
    }
    .faq-question {
      font-weight: 700;
      font-size: 1.1rem;
      color: white;
      cursor: pointer;
    }

    /* CTA 表单 */
    #contact {
      background: rgba(8, 12, 24, 0.9);
      backdrop-filter: blur(8px);
      padding: 64px 0;
    }
    .form-row {
      display: flex;
      gap: 20px;
      margin-bottom: 18px;
    }
    .form-row input {
      flex: 1;
      background: rgba(255,255,255,0.05);
      border: 1px solid rgba(0,229,255,0.3);
      border-radius: 8px;
      padding: 14px;
    }

    footer { padding: 48px 0 24px; border-top: 1px solid var(--accent-cyan); }