/* roulang page: index */
:root {
      --deep-space: #0A0E27;
      --cyan: #00F0FF;
      --orange: #FF6B35;
      --white: #FFFFFF;
      --text-soft: rgba(255,255,255,0.75);
      --text-muted: rgba(255,255,255,0.5);
      --glass-bg: rgba(255,255,255,0.03);
      --glass-border: rgba(0,240,255,0.15);
      --border-light: rgba(255,255,255,0.05);
      --radius-card: 16px;
      --radius-btn: 12px;
      --shadow-card: 0 8px 32px rgba(0,0,0,0.4);
      --shadow-glow: 0 0 20px rgba(0,240,255,0.4);
      --font-sans: "PingFang SC", "Microsoft YaHei", "Helvetica Neue", sans-serif;
    }
    * {
      margin: 0;
      padding: 0;
      box-sizing: border-box;
    }
    body {
      font-family: var(--font-sans);
      background-color: var(--deep-space);
      color: var(--white);
      line-height: 1.5;
      -webkit-font-smoothing: antialiased;
      overflow-x: hidden;
    }
    .container {
      max-width: 1200px;
      margin: 0 auto;
      padding: 0 24px;
    }
    /* 背景网格与粒子 */
    body::before {
      content: "";
      position: fixed;
      top: 0; left: 0; width: 100%; height: 100%;
      background-image: 
        linear-gradient(rgba(0,240,255,0.03) 1px, transparent 1px),
        linear-gradient(90deg, rgba(0,240,255,0.03) 1px, transparent 1px);
      background-size: 40px 40px;
      pointer-events: none;
      z-index: -1;
    }
    /* 导航 */
    .nav {
      position: fixed;
      top: 0; left: 0; width: 100%;
      height: 72px;
      background: rgba(10,14,39,0.8);
      backdrop-filter: blur(20px);
      -webkit-backdrop-filter: blur(20px);
      border-bottom: 1px solid rgba(0,240,255,0.1);
      z-index: 1000;
      display: flex;
      align-items: center;
      transition: background 0.3s, border-color 0.3s;
    }
    .nav.scrolled {
      background: rgba(10,14,39,0.96);
      border-bottom: 1px solid rgba(0,240,255,0.25);
    }
    .nav-inner {
      display: flex;
      justify-content: space-between;
      align-items: center;
      width: 100%;
    }
    .logo {
      font-size: 1.8rem;
      font-weight: 700;
      background: linear-gradient(135deg, #00F0FF, #5B8DEF);
      -webkit-background-clip: text;
      -webkit-text-fill-color: transparent;
      background-clip: text;
      letter-spacing: 1px;
    }
    .nav-links {
      display: flex;
      gap: 2rem;
      list-style: none;
    }
    .nav-links a {
      color: rgba(255,255,255,0.8);
      text-decoration: none;
      font-weight: 500;
      font-size: 1rem;
      transition: color 0.2s;
      position: relative;
    }
    .nav-links a:hover {
      color: var(--cyan);
    }
    .nav-cta {
      background: linear-gradient(135deg, #00F0FF, #0088CC);
      border: none;
      color: #0A0E27;
      font-weight: 700;
      padding: 10px 24px;
      border-radius: var(--radius-btn);
      cursor: pointer;
      font-size: 0.95rem;
      transition: all 0.3s;
      box-shadow: 0 0 15px rgba(0,240,255,0.3);
      white-space: nowrap;
    }
    .nav-cta:hover {
      filter: brightness(1.15);
      box-shadow: var(--shadow-glow);
    }
    .hamburger {
      display: none;
      flex-direction: column;
      gap: 6px;
      background: none;
      border: none;
      cursor: pointer;
      padding: 8px;
    }
    .hamburger span {
      display: block;
      width: 28px;
      height: 2px;
      background: var(--cyan);
      transition: 0.3s;
    }
    /* 区块通用 */
    section {
      padding: 100px 0;
      position: relative;
    }
    h2 {
      font-size: 2.25rem;
      font-weight: 600;
      margin-bottom: 0.5rem;
      position: relative;
      display: inline-block;
    }
    h2::after {
      content: '';
      position: absolute;
      left: 0; bottom: -8px;
      width: 48px;
      height: 4px;
      background: var(--cyan);
      border-radius: 4px;
    }
    /* 按钮 */
    .btn-primary {
      background: linear-gradient(135deg, #00F0FF, #0088CC);
      color: #0A0E27;
      font-weight: 700;
      padding: 14px 32px;
      border-radius: var(--radius-btn);
      border: none;
      cursor: pointer;
      transition: 0.3s;
      box-shadow: 0 0 18px rgba(0,240,255,0.25);
      display: inline-block;
      text-decoration: none;
    }
    .btn-primary:hover {
      filter: brightness(1.15);
      box-shadow: var(--shadow-glow);
    }
    .btn-ghost {
      background: transparent;
      border: 1.5px solid var(--cyan);
      color: var(--cyan);
      padding: 14px 32px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      cursor: pointer;
      transition: 0.3s;
      text-decoration: none;
    }
    .btn-ghost:hover {
      background: rgba(0,240,255,0.08);
      box-shadow: 0 0 15px rgba(0,240,255,0.5);
    }
    /* Hero */
    #hero {
      min-height: 100vh;
      display: flex;
      align-items: center;
      background: linear-gradient(180deg, rgba(10,14,39,0.65) 0%, #0A0E27 95%), url('/assets/images/backpic/back-1.webp') center/cover no-repeat;
      background-blend-mode: overlay;
      padding-top: 72px;
    }
    .hero-grid {
      display: flex;
      align-items: center;
      gap: 3rem;
    }
    .hero-text {
      flex: 1;
    }
    .hero-text h1 {
      font-size: 3rem;
      font-weight: 700;
      line-height: 1.2;
      margin-bottom: 1.5rem;
      color: #FFFFFF;
    }
    .hero-text h1 span {
      color: var(--orange);
    }
    .hero-sub {
      font-size: 1.2rem;
      color: rgba(255,255,255,0.8);
      margin-bottom: 2.5rem;
    }
    .hero-buttons {
      display: flex;
      gap: 1rem;
      flex-wrap: wrap;
    }
    .hero-visual {
      flex: 1;
      display: flex;
      justify-content: center;
    }
    /* 卡片 */
    .card {
      background: var(--glass-bg);
      backdrop-filter: blur(20px);
      -webkit-backdrop-filter: blur(20px);
      border: 1px solid var(--glass-border);
      border-radius: var(--radius-card);
      padding: 2rem;
      box-shadow: var(--shadow-card);
      transition: transform 0.3s, box-shadow 0.3s;
    }
    .card:hover {
      transform: translateY(-6px);
      box-shadow: 0 12px 40px rgba(0,240,255,0.2);
    }
    .grid-3 {
      display: grid;
      grid-template-columns: repeat(3,1fr);
      gap: 24px;
      margin-top: 2.5rem;
    }
    .grid-4 {
      display: grid;
      grid-template-columns: repeat(4,1fr);
      gap: 1.5rem;
      margin-top: 2rem;
    }
    .service-row {
      display: flex;
      gap: 3rem;
      align-items: center;
      margin-top: 2rem;
    }
    .process-steps {
      display: flex;
      gap: 2rem;
      margin-top: 2.5rem;
    }
    .step-card {
      background: rgba(255,255,255,0.04);
      border-radius: 20px;
      padding: 2rem;
      flex: 1;
      position: relative;
    }
    .step-number {
      font-size: 3rem;
      font-weight: 800;
      background: linear-gradient(180deg, #00F0FF, transparent);
      -webkit-background-clip: text;
      -webkit-text-fill-color: transparent;
      background-clip: text;
    }
    .faq-item {
      background: rgba(255,255,255,0.02);
      border-bottom: 1px solid rgba(255,255,255,0.05);
      padding: 1rem 0;
      cursor: pointer;
    }
    .faq-question {
      display: flex;
      justify-content: space-between;
      font-weight: 600;
      font-size: 1.1rem;
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.4s ease;
      color: var(--text-soft);
    }
    .footer {
      background: #0C1230;
      border-top: 2px solid var(--cyan);
      padding: 3rem 0 1.5rem;
    }
    @media (max-width: 1024px) {
      .grid-3 { grid-template-columns: repeat(2,1fr); }
      .grid-4 { grid-template-columns: repeat(2,1fr); }
    }
    @media (max-width: 768px) {
      .nav-links, .nav-cta { display: none; }
      .hamburger { display: flex; }
      .hero-grid { flex-direction: column; text-align: center; }
      .hero-text h1 { font-size: 2.2rem; }
      .grid-3, .grid-4 { grid-template-columns: 1fr; }
      .service-row { flex-direction: column; }
      .process-steps { flex-direction: column; }
      section { padding: 70px 0; }
    }
    .modal {
      display: none;
      position: fixed;
      top:0;left:0;width:100%;height:100%;
      background: rgba(0,0,0,0.7);
      backdrop-filter: blur(8px);
      align-items: center;
      justify-content: center;
      z-index: 2000;
    }
    .modal.active { display: flex; }
    .modal-card {
      background: rgba(20,25,45,0.9);
      backdrop-filter: blur(30px);
      border:1px solid var(--glass-border);
      border-radius: 24px;
      padding: 2rem;
      max-width: 420px;
      width: 90%;
    }
    input {
      width: 100%;
      padding: 12px;
      background: rgba(0,0,0,0.4);
      border:1px solid rgba(255,255,255,0.2);
      border-radius: 10px;
      color:white;
      margin: 10px 0;
    }
    input:focus { border-color: var(--cyan); outline: none; }