/* roulang page: index */
/* ----- 设计变量与基础重置 ----- */
    :root {
      --primary-deep: #0A0E27;
      --accent-cyan: #00F0FF;
      --secondary-gray: #1A1F3A;
      --neutral-light: #F4F6F9;
      --mid-gray: #8E94A4;
      --white: #FFFFFF;
      --signal-green: #00E676;
      --alert-red: #FF1744;
      --border-light: rgba(255,255,255,0.08);
      --radius-card: 12px;
      --radius-btn: 8px;
      --radius-input: 6px;
      --shadow-card: 0 4px 20px rgba(0,0,0,0.08);
      --shadow-glow: 0 0 20px rgba(0,240,255,0.4);
      --font-sans: "PingFang SC", "Microsoft YaHei", "Hiragino Sans GB", sans-serif;
      --font-mono: "Inter", "SF Pro Display", sans-serif;
      --transition-smooth: all 0.3s cubic-bezier(0.25, 0.46, 0.45, 0.94);
    }

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

    html {
      scroll-behavior: smooth;
      font-size: 16px;
    }

    body {
      font-family: var(--font-sans);
      background-color: var(--primary-deep);
      color: var(--mid-gray);
      line-height: 1.8;
      overflow-x: hidden;
      font-weight: 400;
    }

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

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

    button, input {
      font-family: inherit;
      outline: none;
      border: none;
      background: transparent;
    }

    .container {
      max-width: 1320px;
      margin: 0 auto;
      padding: 0 24px;
    }

    /* 标题层级 */
    h1 {
      font-size: 56px;
      line-height: 1.2;
      font-weight: 800;
      letter-spacing: -0.02em;
      color: var(--white);
    }
    h2 {
      font-size: 40px;
      line-height: 1.3;
      font-weight: 700;
      color: var(--white);
    }
    h3 {
      font-size: 24px;
      line-height: 1.4;
      font-weight: 600;
      color: var(--white);
    }

    /* 沉浸式导航 */
    .header {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      z-index: 1000;
      background: rgba(10, 14, 39, 0.85);
      backdrop-filter: blur(12px);
      -webkit-backdrop-filter: blur(12px);
      border-bottom: 1px solid var(--border-light);
    }
    .nav-container {
      display: flex;
      align-items: center;
      justify-content: space-between;
      height: 72px;
    }
    .logo {
      font-family: var(--font-mono);
      font-size: 1.6rem;
      font-weight: 700;
      color: var(--white);
      letter-spacing: 1px;
      display: flex;
      align-items: center;
      gap: 8px;
    }
    .logo .signal-wave {
      display: inline-block;
      width: 8px;
      height: 18px;
      background: var(--accent-cyan);
      border-radius: 4px;
      margin-right: 2px;
      animation: pulseWave 1.4s infinite ease-in-out;
    }
    .logo .signal-wave:nth-child(2) { height: 26px; animation-delay: 0.2s; }
    .logo .signal-wave:nth-child(3) { height: 34px; animation-delay: 0.4s; }

    @keyframes pulseWave {
      0%, 100% { opacity: 0.6; transform: scaleY(0.9); }
      50% { opacity: 1; transform: scaleY(1.1); }
    }

    .nav-links {
      display: flex;
      gap: 2.2rem;
      align-items: center;
    }
    .nav-links a {
      color: var(--white);
      font-weight: 500;
      font-size: 0.95rem;
      position: relative;
      padding: 4px 0;
    }
    .nav-links a::after {
      content: '';
      position: absolute;
      bottom: -4px;
      left: 0;
      width: 0;
      height: 2px;
      background: var(--accent-cyan);
      transition: width 0.25s ease;
    }
    .nav-links a:hover::after,
    .nav-links a.active::after {
      width: 100%;
    }

    .hamburger {
      display: none;
      flex-direction: column;
      gap: 5px;
      cursor: pointer;
      background: transparent;
    }
    .hamburger span {
      width: 26px;
      height: 2px;
      background: var(--white);
      transition: var(--transition-smooth);
    }

    /* 移动端导航遮罩 */
    .mobile-menu {
      display: none;
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      height: 100vh;
      background: rgba(10, 14, 39, 0.98);
      backdrop-filter: blur(30px);
      flex-direction: column;
      justify-content: center;
      align-items: center;
      gap: 2.5rem;
      z-index: 999;
      opacity: 0;
      pointer-events: none;
      transition: opacity 0.4s ease;
    }
    .mobile-menu.active {
      display: flex;
      opacity: 1;
      pointer-events: auto;
    }
    .mobile-menu a {
      font-size: 2rem;
      font-weight: 600;
      color: var(--white);
    }

    /* 按钮系统 */
    .btn {
      display: inline-flex;
      align-items: center;
      justify-content: center;
      padding: 14px 36px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      font-size: 1rem;
      cursor: pointer;
      transition: var(--transition-smooth);
      gap: 8px;
    }
    .btn-primary {
      background: var(--accent-cyan);
      color: var(--primary-deep);
      border: 2px solid var(--accent-cyan);
    }
    .btn-primary:hover {
      background: #33f5ff;
      box-shadow: var(--shadow-glow);
      transform: translateY(-2px);
    }
    .btn-outline {
      background: transparent;
      color: var(--accent-cyan);
      border: 2px solid var(--accent-cyan);
    }
    .btn-outline:hover {
      background: rgba(0, 240, 255, 0.1);
      box-shadow: 0 0 18px rgba(0,240,255,0.3);
    }

    /* Hero 双栏杂志布局 */
    .hero-section {
      padding: 140px 0 100px;
      display: flex;
      align-items: center;
      gap: 48px;
    }
    .hero-left {
      flex: 1;
      animation: slideInLeft 0.8s ease;
    }
    .hero-right {
      flex: 1.2;
      animation: fadeInScale 0.9s ease;
    }
    @keyframes slideInLeft {
      from { opacity: 0; transform: translateX(-40px); }
      to { opacity: 1; transform: translateX(0); }
    }
    @keyframes fadeInScale {
      from { opacity: 0; transform: scale(0.92); }
      to { opacity: 1; transform: scale(1); }
    }
    .hero-img {
      border-radius: 24px;
      box-shadow: 0 0 40px rgba(0,240,255,0.2);
      border: 1px solid rgba(0,240,255,0.25);
      width: 100%;
    }
    .hero-sub {
      font-size: 1.15rem;
      color: #B0B8C5;
      margin: 20px 0 32px;
      max-width: 480px;
    }
    .hero-buttons {
      display: flex;
      gap: 20px;
      flex-wrap: wrap;
    }

    /* 板块通用 */
    .section {
      padding: 120px 0;
    }
    .section-title {
      margin-bottom: 24px;
      position: relative;
    }
    .section-title::after {
      content: '';
      display: block;
      width: 48px;
      height: 3px;
      background: var(--accent-cyan);
      margin-top: 12px;
    }

    /* 核心优势非对称网格 */
    .advantages-grid {
      display: grid;
      grid-template-columns: 1.3fr 0.7fr;
      gap: 24px;
      margin-top: 48px;
    }
    .adv-card {
      background: var(--secondary-gray);
      border-radius: var(--radius-card);
      padding: 40px;
      transition: var(--transition-smooth);
    }
    .adv-card:hover {
      border: 1px solid var(--accent-cyan);
      transform: translateY(-4px);
      box-shadow: 0 12px 32px rgba(0,240,255,0.15);
    }
    .adv-card.large {
      grid-row: span 2;
    }
    .adv-stat {
      font-family: var(--font-mono);
      font-size: 3.5rem;
      font-weight: 700;
      color: var(--accent-cyan);
      line-height: 1.1;
    }
    .second-row {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
      margin-top: 24px;
    }

    /* 解决方案瀑布流 */
    .solutions-masonry {
      display: grid;
      grid-template-columns: repeat(2, 1fr);
      gap: 32px;
      margin-top: 48px;
    }
    .sol-card {
      background: var(--secondary-gray);
      border-radius: var(--radius-card);
      overflow: hidden;
    }
    .sol-card img {
      transition: transform 0.4s ease;
      width: 100%;
      height: 220px;
      object-fit: cover;
    }
    .sol-card:hover img {
      transform: scale(1.03);
    }
    .sol-text {
      padding: 28px;
    }

    /* 对比表 */
    .comparison-wrapper {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 32px;
      margin-top: 56px;
    }
    .compare-col {
      background: #1E2338;
      border-radius: 20px;
      padding: 42px;
    }
    .compare-col.highlight {
      border-left: 4px solid var(--accent-cyan);
      background: linear-gradient(145deg, #141a30, #0f1328);
    }
    .compare-item {
      display: flex;
      align-items: center;
      gap: 16px;
      margin: 24px 0;
    }

    /* FAQ */
    .faq-list {
      max-width: 800px;
      margin: 48px auto 0;
    }
    .faq-item {
      background: #1E2338;
      border-left: 4px solid var(--accent-cyan);
      margin-bottom: 16px;
      border-radius: 0 12px 12px 0;
    }
    .faq-question {
      padding: 24px;
      font-weight: 600;
      cursor: pointer;
      display: flex;
      justify-content: space-between;
    }
    .faq-answer {
      padding: 0 24px 24px;
      display: none;
    }
    .faq-item.active .faq-answer {
      display: block;
    }

    /* CTA */
    .cta-card {
      background: var(--secondary-gray);
      border-radius: 28px;
      padding: 64px;
      text-align: center;
      max-width: 720px;
      margin: 0 auto;
    }
    .input-field {
      width: 100%;
      padding: 14px;
      background: #10152b;
      border: 1px solid #2f3855;
      border-radius: var(--radius-input);
      color: white;
      margin: 14px 0;
    }
    .input-field:focus {
      border-color: var(--accent-cyan);
    }

    .footer {
      background: #060918;
      padding: 70px 0 30px;
    }
    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1fr;
      gap: 40px;
    }

    @media (max-width: 1024px) {
      h1 { font-size: 44px; }
      .hero-section { flex-direction: column; }
      .advantages-grid, .second-row { grid-template-columns: 1fr; }
      .solutions-masonry { grid-template-columns: 1fr; }
      .comparison-wrapper { grid-template-columns: 1fr; }
    }
    @media (max-width: 768px) {
      .nav-links { display: none; }
      .hamburger { display: flex; }
      h1 { font-size: 36px; }
      .footer-grid { grid-template-columns: 1fr; }
    }