/* roulang page: index */
:root {
      --deep-purple-black: #120524;
      --dark-gradient-start: #1a0a2e;
      --dark-gradient-end: #0d0d1a;
      --vivid-purple: #b347ea;
      --energy-gold: #f0a500;
      --white: #ffffff;
      --light-gray: #f5f3f7;
      --off-white: #eae6f0;
      --text-dark: #1a1a2e;
      --text-mid: #4a4a5e;
      --text-light: #cccccc;
      --radius-card: 12px;
      --radius-btn: 8px;
      --radius-input: 6px;
      --shadow-card: 0 8px 30px rgba(0, 0, 0, 0.06);
      --shadow-card-hover: 0 18px 40px rgba(179, 71, 234, 0.15);
      --transition-default: all 0.3s ease;
    }

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

    body {
      font-family: "PingFang SC", "Microsoft YaHei", "Noto Sans SC", system-ui, -apple-system, sans-serif;
      background-color: var(--white);
      color: var(--text-dark);
      line-height: 1.75;
      font-size: 16px;
      -webkit-font-smoothing: antialiased;
    }

    .container {
      max-width: 1200px;
      margin: 0 auto;
      padding: 0 24px;
    }

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

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

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

    h1, h2, h3, h4 {
      font-weight: 700;
      line-height: 1.3;
    }

    h1 {
      font-size: clamp(36px, 8vw, 52px);
      letter-spacing: 2px;
      color: var(--white);
      text-shadow: 0 0 50px rgba(179, 71, 234, 0.5);
    }

    h2 {
      font-size: 36px;
      text-align: center;
      margin-bottom: 1.5rem;
    }

    .text-gradient {
      background: linear-gradient(135deg, var(--vivid-purple) 0%, var(--energy-gold) 100%);
      -webkit-background-clip: text;
      -webkit-text-fill-color: transparent;
      background-clip: text;
    }

    /* 导航栏沉浸式 */
    .header {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      background: rgba(13, 13, 26, 0.88);
      backdrop-filter: blur(12px);
      border-bottom: 1px solid rgba(179, 71, 234, 0.3);
      z-index: 1000;
      padding: 15px 0;
      transition: var(--transition-default);
    }

    .header-inner {
      display: flex;
      align-items: center;
      justify-content: space-between;
      max-width: 1200px;
      margin: 0 auto;
      padding: 0 24px;
    }

    .logo {
      font-size: 26px;
      font-weight: 700;
      background: linear-gradient(135deg, #c476ff 0%, var(--energy-gold) 100%);
      -webkit-background-clip: text;
      -webkit-text-fill-color: transparent;
      background-clip: text;
      letter-spacing: 1px;
    }

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

    .nav-link {
      color: var(--white);
      font-weight: 500;
      position: relative;
      padding: 5px 0;
    }

    .nav-link::after {
      content: "";
      position: absolute;
      bottom: 0;
      left: 50%;
      transform: translateX(-50%);
      width: 0;
      height: 2px;
      background: var(--energy-gold);
      transition: width 0.3s ease;
    }

    .nav-link:hover {
      color: var(--energy-gold);
    }

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

    .btn-primary {
      background: linear-gradient(135deg, var(--vivid-purple), var(--energy-gold));
      color: var(--white);
      font-weight: 600;
      padding: 12px 28px;
      border-radius: var(--radius-btn);
      border: none;
      cursor: pointer;
      transition: var(--transition-default);
      box-shadow: 0 4px 15px rgba(179, 71, 234, 0.4);
      display: inline-block;
      text-align: center;
    }

    .btn-primary:hover {
      filter: brightness(1.15);
      box-shadow: 0 8px 25px rgba(179, 71, 234, 0.7);
      transform: translateY(-1px);
    }

    .btn-outline {
      background: transparent;
      border: 2px solid var(--white);
      color: var(--white);
      font-weight: 600;
      padding: 12px 28px;
      border-radius: var(--radius-btn);
      cursor: pointer;
      transition: var(--transition-default);
    }

    .btn-outline:hover {
      background: rgba(179, 71, 234, 0.2);
      border-color: var(--vivid-purple);
      box-shadow: 0 0 20px rgba(179, 71, 234, 0.5);
    }

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

    .hamburger span {
      width: 25px;
      height: 3px;
      background: var(--white);
      border-radius: 3px;
      transition: var(--transition-default);
    }

    /* 移动端菜单 */
    @media (max-width: 1024px) {
      .nav-menu {
        position: fixed;
        top: 0;
        right: -100%;
        width: 75%;
        max-width: 320px;
        height: 100vh;
        background: rgba(8, 4, 18, 0.97);
        backdrop-filter: blur(20px);
        flex-direction: column;
        justify-content: center;
        align-items: center;
        transition: right 0.4s ease;
        gap: 2rem;
        box-shadow: -5px 0 25px rgba(0,0,0,0.5);
      }
      .nav-menu.active {
        right: 0;
      }
      .hamburger {
        display: flex;
        z-index: 1100;
      }
    }

    @media (max-width: 768px) {
      .container {
        padding: 0 16px;
      }
      h1 {
        font-size: 36px;
      }
      h2 {
        font-size: 28px;
      }
    }

    /* Hero 全屏 */
    .hero {
      height: 100vh;
      background: linear-gradient(135deg, rgba(26,10,46,0.82) 0%, rgba(13,13,26,0.92) 100%), url('/assets/images/backpic/back-1.webp') center/cover no-repeat;
      display: flex;
      align-items: center;
      justify-content: center;
      text-align: center;
      position: relative;
      overflow: hidden;
    }
    .hero::after {
      content: "";
      position: absolute;
      width: 100%;
      height: 100%;
      background: radial-gradient(circle at 30% 40%, rgba(179,71,234,0.12) 0%, transparent 60%);
      pointer-events: none;
    }
    .hero-content {
      position: relative;
      z-index: 2;
      max-width: 700px;
    }
    .hero-sub {
      font-size: 20px;
      color: var(--text-light);
      margin: 20px 0 32px;
    }

    .section {
      padding: 80px 0;
    }

    .bg-light {
      background-color: var(--light-gray);
    }

    .bg-dark {
      background: linear-gradient(135deg, #140430, #0d0d1a);
    }

    /* 卡片网格 */
    .grid-4 {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 24px;
      margin-top: 2.5rem;
    }
    @media (max-width: 1024px) { .grid-4 { grid-template-columns: repeat(2, 1fr); } }
    @media (max-width: 640px) { .grid-4 { grid-template-columns: 1fr; } }

    .service-card {
      background: var(--white);
      border-radius: var(--radius-card);
      box-shadow: var(--shadow-card);
      overflow: hidden;
      transition: var(--transition-default);
    }
    .service-card:hover {
      transform: translateY(-10px);
      box-shadow: var(--shadow-card-hover);
    }
    .card-img {
      width: 100%;
      height: 200px;
      object-fit: cover;
    }
    .card-body {
      padding: 24px;
    }
    .card-icon {
      font-size: 2rem;
      color: var(--vivid-purple);
      margin-bottom: 12px;
    }
    .card-title {
      font-size: 22px;
      font-weight: 700;
      margin-bottom: 10px;
    }
    .card-desc {
      color: var(--text-mid);
      font-size: 15px;
    }

    .adv-row {
      display: flex;
      justify-content: space-around;
      text-align: center;
    }
    .adv-item {
      flex: 1;
      padding: 20px;
    }
    .adv-number {
      font-size: 48px;
      font-weight: 800;
      color: var(--energy-gold);
    }
    .adv-label {
      color: var(--white);
      font-size: 18px;
      margin: 8px 0;
    }
    .adv-desc {
      color: var(--text-light);
    }

    .cases-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
      margin-top: 2rem;
    }
    @media (max-width: 1024px) { .cases-grid { grid-template-columns: repeat(2, 1fr); } }
    @media (max-width: 640px) { .cases-grid { grid-template-columns: 1fr; } }

    .case-card {
      background: white;
      border-radius: var(--radius-card);
      overflow: hidden;
      box-shadow: var(--shadow-card);
      transition: var(--transition-default);
    }
    .case-card:hover {
      box-shadow: var(--shadow-card-hover);
    }
    .case-img-wrap {
      overflow: hidden;
      height: 200px;
    }
    .case-img {
      width: 100%;
      height: 100%;
      object-fit: cover;
      transition: transform 0.4s ease;
    }
    .case-card:hover .case-img {
      transform: scale(1.05);
    }
    .case-text {
      padding: 16px;
    }

    .solution-block {
      display: flex;
      align-items: center;
      gap: 40px;
      margin-bottom: 60px;
    }
    .solution-img {
      width: 50%;
      border-radius: var(--radius-card);
      object-fit: cover;
    }
    @media (max-width: 768px) {
      .solution-block { flex-direction: column; }
      .solution-img { width: 100%; }
    }

    .accordion-item {
      background: var(--white);
      margin-bottom: 12px;
      border-radius: var(--radius-card);
      box-shadow: 0 4px 15px rgba(0,0,0,0.04);
    }
    .accordion-header {
      padding: 18px 24px;
      display: flex;
      justify-content: space-between;
      align-items: center;
      cursor: pointer;
      font-weight: 600;
    }
    .accordion-content {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.4s ease;
      padding: 0 24px;
    }
    .accordion-content.open {
      max-height: 300px;
      padding-bottom: 20px;
    }

    .footer {
      background: #0c041a;
      color: var(--text-light);
      padding: 50px 0 20px;
    }
    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr;
      gap: 30px;
      margin-bottom: 30px;
    }
    @media (max-width: 768px) { .footer-grid { grid-template-columns: 1fr; } }

    .social-icons span {
      display: inline-block;
      width: 36px;
      height: 36px;
      border: 1px solid #555;
      border-radius: 50%;
      line-height: 36px;
      text-align: center;
      margin-right: 8px;
      background: transparent;
      color: white;
    }
    input, textarea {
      width: 100%;
      padding: 12px;
      border: 1px solid #e0dce4;
      border-radius: var(--radius-input);
      margin-bottom: 16px;
      outline: none;
      transition: 0.2s;
    }
    input:focus, textarea:focus {
      border-color: var(--vivid-purple);
      box-shadow: 0 0 0 3px rgba(179,71,234,0.15);
    }