/* CSS Variables & Reset */
    :root {
      --primary-color: #ffd700; /* 涂鸦亮黄 */
      --secondary-color: #ff1493; /* 涂鸦粉红 */
      --accent-color: #00bfff; /* 涂鸦天蓝 */
      --success-color: #adff2f; /* 荧光绿 */
      --bg-color: #fcfcf9; /* 浅暖色基底 */
      --text-color: #111111;
      --text-muted: #555555;
      --border-width: 3px;
      --border-color: #111111;
      --shadow-offset: 5px;
    }

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

    body {
      font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
      background-color: var(--bg-color);
      color: var(--text-color);
      line-height: 1.6;
      overflow-x: hidden;
    }

    /* Common Layout & Container */
    .ai-container {
      width: 100%;
      max-width: 1200px;
      margin: 0 auto;
      padding: 0 20px;
    }

    section {
      padding: 80px 0;
      border-bottom: var(--border-width) solid var(--border-color);
    }

    /* Graffiti Decorative Classes */
    .graffiti-box {
      background: #ffffff;
      border: var(--border-width) solid var(--border-color);
      border-radius: 12px 4px 12px 4px / 4px 12px 4px 12px;
      box-shadow: var(--shadow-offset) var(--shadow-offset) 0px var(--border-color);
      padding: 30px;
      transition: all 0.2s ease-in-out;
    }

    .graffiti-box:hover {
      transform: translate(-3px, -3px);
      box-shadow: 8px 8px 0px var(--border-color);
    }

    .graffiti-btn {
      display: inline-block;
      text-decoration: none;
      color: var(--text-color);
      font-weight: bold;
      padding: 12px 28px;
      background-color: var(--primary-color);
      border: var(--border-width) solid var(--border-color);
      border-radius: 6px;
      box-shadow: 4px 4px 0px var(--border-color);
      cursor: pointer;
      transition: all 0.15s ease;
      text-align: center;
    }

    .graffiti-btn:hover {
      transform: translate(-2px, -2px);
      box-shadow: 6px 6px 0px var(--border-color);
    }

    .graffiti-btn:active {
      transform: translate(2px, 2px);
      box-shadow: 0px 0px 0px var(--border-color);
    }

    .graffiti-btn.secondary {
      background-color: var(--accent-color);
    }

    .graffiti-btn.success {
      background-color: var(--success-color);
    }

    .section-title {
      font-size: 2.2rem;
      font-weight: 900;
      text-align: center;
      margin-bottom: 50px;
      position: relative;
      display: inline-block;
      left: 50%;
      transform: translateX(-50%);
      padding: 5px 15px;
      background: var(--success-color);
      border: var(--border-width) solid var(--border-color);
      border-radius: 4px;
      box-shadow: 4px 4px 0px var(--border-color);
    }

    /* Header & Navigation */
    header {
      position: sticky;
      top: 0;
      z-index: 1000;
      background-color: #ffffff;
      border-bottom: var(--border-width) solid var(--border-color);
      padding: 15px 0;
    }

    .nav-wrapper {
      display: flex;
      justify-content: space-between;
      align-items: center;
    }

    .logo-area {
      display: flex;
      align-items: center;
      gap: 10px;
    }

    .ai-page-logo {
      height: 45px;
      width: auto;
    }

    .nav-menu {
      display: flex;
      list-style: none;
    }

    .nav-menu a {
      text-decoration: none;
      color: var(--text-color);
      font-weight: bold;
      font-size: 0.95rem;
      padding: 6px 12px;
      border-radius: 4px;
      transition: all 0.2s;
    }

    .nav-menu a:hover {
      background-color: var(--primary-color);
      outline: 2px solid var(--border-color);
    }

    .mobile-menu-toggle {
      display: none;
      font-size: 1.5rem;
      background: none;
      border: none;
      cursor: pointer;
    }

    /* Hero Section (No Image Allowed) */
    .hero-section {
      background: linear-gradient(135deg, #fff7c2 0%, #ffe3e3 100%);
      text-align: center;
      padding: 100px 0;
    }

    .hero-title {
      font-size: 3rem;
      font-weight: 900;
      line-height: 1.2;
      margin-bottom: 25px;
      color: var(--text-color);
    }

    .hero-title span {
      background-color: var(--secondary-color);
      color: #fff;
      padding: 2px 10px;
      border-radius: 4px;
      display: inline-block;
      transform: rotate(-1deg);
      border: 2px solid #000;
    }

    .hero-subtitle {
      font-size: 1.25rem;
      margin-bottom: 40px;
      color: var(--text-muted);
      max-width: 800px;
      margin-left: auto;
      margin-right: auto;
    }

    .hero-buttons {
      display: flex;
      justify-content: center;
      gap: 20px;
      flex-wrap: wrap;
      margin-bottom: 40px;
    }

    .hero-features {
      display: grid;
      grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
      gap: 20px;
      margin-top: 50px;
    }

    .hero-badge {
      background: #ffffff;
      border: 2px solid var(--border-color);
      padding: 15px;
      border-radius: 8px;
      font-weight: bold;
      box-shadow: 3px 3px 0 var(--border-color);
    }

    /* About Us */
    .about-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 50px;
      align-items: center;
    }

    .about-text h3 {
      font-size: 1.8rem;
      margin-bottom: 20px;
    }

    .about-text p {
      margin-bottom: 15px;
      color: var(--text-muted);
    }

    .about-image-wrapper {
      border: var(--border-width) solid var(--border-color);
      box-shadow: 8px 8px 0px var(--border-color);
      border-radius: 8px;
      overflow: hidden;
      background-color: #fff;
    }

    /* Service System */
    .services-grid {
      display: grid;
      grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
      gap: 30px;
    }

    .tag-cloud {
      display: flex;
      flex-wrap: wrap;
      gap: 10px;
      margin-top: 20px;
    }

    .tag-cloud span {
      background-color: #eee;
      border: 1px solid var(--border-color);
      padding: 5px 10px;
      border-radius: 20px;
      font-size: 0.85rem;
      font-weight: 500;
    }

    /* Process Section */
    .process-timeline {
      display: grid;
      grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
      gap: 30px;
      position: relative;
    }

    .process-step {
      position: relative;
    }

    .step-number {
      font-size: 3rem;
      font-weight: 900;
      color: var(--secondary-color);
      line-height: 1;
      margin-bottom: 10px;
    }

    /* Solutions */
    .solutions-grid {
      display: grid;
      grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
      gap: 30px;
    }

    /* Network */
    .network-container {
      text-align: center;
    }

    .network-list {
      display: flex;
      flex-wrap: wrap;
      justify-content: center;
      gap: 15px;
      margin-top: 30px;
    }

    .network-badge {
      background: var(--accent-color);
      padding: 10px 20px;
      border: 2px solid var(--border-color);
      font-weight: bold;
      border-radius: 4px;
      box-shadow: 3px 3px 0 var(--border-color);
    }

    /* Standards & Technical */
    .standards-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 40px;
    }

    /* Cases */
    .cases-grid {
      display: grid;
      grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
      gap: 30px;
    }

    .case-card {
      overflow: hidden;
      display: flex;
      flex-direction: column;
    }

    .case-img-container {
      width: 100%;
      height: 200px;
      overflow: hidden;
      border-bottom: var(--border-width) solid var(--border-color);
      background-color: #eee;
    }

    .case-img-container img {
      width: 100%;
      height: 100%;
      object-fit: cover;
    }

    .case-content {
      padding: 20px;
      flex-grow: 1;
    }

    /* Evaluation Table */
    .table-responsive {
      overflow-x: auto;
      border: var(--border-width) solid var(--border-color);
      border-radius: 8px;
      box-shadow: 6px 6px 0px var(--border-color);
      background: #fff;
    }

    .eval-table {
      width: 100%;
      border-collapse: collapse;
      text-align: left;
      min-width: 600px;
    }

    .eval-table th, .eval-table td {
      padding: 15px 20px;
      border-bottom: 2px solid var(--border-color);
    }

    .eval-table th {
      background-color: var(--primary-color);
      color: var(--text-color);
      font-weight: bold;
    }

    .eval-table tr:last-child td {
      border-bottom: none;
    }

    .rating-summary {
      background: var(--success-color);
      padding: 25px;
      border: var(--border-width) solid var(--border-color);
      border-radius: 8px;
      margin-top: 30px;
      display: flex;
      align-items: center;
      justify-content: space-between;
      flex-wrap: wrap;
      gap: 20px;
    }

    .rating-stars {
      font-size: 1.5rem;
      color: #ff4500;
    }

    /* Form & Matching */
    .form-wrapper {
      max-width: 700px;
      margin: 0 auto;
    }

    .form-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 20px;
      margin-bottom: 20px;
    }

    .form-group {
      display: flex;
      flex-direction: column;
      gap: 8px;
    }

    .form-group.full-width {
      grid-column: span 2;
    }

    .form-label {
      font-weight: bold;
      font-size: 0.9rem;
    }

    .form-control {
      padding: 12px;
      border: 2px solid var(--border-color);
      border-radius: 6px;
      font-size: 1rem;
      background-color: #fff;
      font-family: inherit;
    }

    .form-control:focus {
      outline: none;
      border-color: var(--secondary-color);
      box-shadow: 3px 3px 0 var(--border-color);
    }

    /* Token Price & Help */
    .token-grid {
      display: grid;
      grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
      gap: 25px;
    }

    /* Training Programs */
    .training-grid {
      display: grid;
      grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
      gap: 30px;
    }

    /* Testimonials (6 reviews) */
    .testimonials-grid {
      display: grid;
      grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
      gap: 35px;
    }

    .testimonial-card {
      display: flex;
      flex-direction: column;
      justify-content: space-between;
    }

    .user-info {
      display: flex;
      align-items: center;
      gap: 15px;
      margin-top: 20px;
      padding-top: 15px;
      border-top: 1px dashed var(--border-color);
    }

    .user-avatar {
      width: 45px;
      height: 45px;
      background-color: var(--accent-color);
      border-radius: 50%;
      display: flex;
      align-items: center;
      justify-content: center;
      font-weight: bold;
      border: 2px solid var(--border-color);
    }

    /* FAQ accordion */
    .faq-accordion {
      max-width: 900px;
      margin: 0 auto;
      display: flex;
      flex-direction: column;
      gap: 15px;
    }

    .faq-item {
      border: 2px solid var(--border-color);
      border-radius: 6px;
      background: #ffffff;
      overflow: hidden;
    }

    .faq-header {
      padding: 18px 24px;
      background-color: #ffffff;
      cursor: pointer;
      display: flex;
      justify-content: space-between;
      align-items: center;
      font-weight: bold;
      transition: background 0.2s;
    }

    .faq-header:hover {
      background-color: #fbfbfb;
    }

    .faq-icon {
      font-size: 1.2rem;
      transition: transform 0.2s;
    }

    .faq-content {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.2s ease-out;
      background-color: #fafaf5;
      border-top: 0px solid var(--border-color);
    }

    .faq-content-inner {
      padding: 20px 24px;
      color: var(--text-muted);
    }

    .faq-item.active .faq-content {
      border-top-width: 2px;
      max-height: 300px;
    }

    .faq-item.active .faq-icon {
      transform: rotate(45deg);
    }

    /* Article List */
    .article-section {
      background-color: #fff8f8;
    }
    
    .article-list {
      display: grid;
      grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
      gap: 25px;
      margin-top: 30px;
    }

    .article-item {
      display: flex;
      flex-direction: column;
      justify-content: space-between;
    }

    .article-item h4 {
      font-size: 1.1rem;
      margin-bottom: 15px;
    }

    /* Footer & Links */
    footer {
      background-color: #111111;
      color: #ffffff;
      padding: 60px 0 30px 0;
      border-top: var(--border-width) solid var(--border-color);
    }

    footer .ai-container {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1.5fr;
      gap: 40px;
    }

    .footer-col h4 {
      color: var(--primary-color);
      font-size: 1.1rem;
      margin-bottom: 20px;
      border-bottom: 2px solid var(--primary-color);
      display: inline-block;
      padding-bottom: 5px;
    }

    .footer-col p {
      color: #cccccc;
      margin-bottom: 10px;
      font-size: 0.9rem;
    }

    .footer-links {
      list-style: none;
    }

    .footer-links li {
      margin-bottom: 10px;
    }

    .footer-links a {
      color: #cccccc;
      text-decoration: none;
      font-size: 0.9rem;
      transition: color 0.2s;
    }

    .footer-links a:hover {
      color: var(--primary-color);
    }

    .friendship-links {
      margin-top: 40px;
      padding-top: 20px;
      border-top: 1px solid #333333;
      display: flex;
      flex-wrap: wrap;
      gap: 15px;
      align-items: center;
    }

    .friendship-links a {
      color: #aaaaaa;
      text-decoration: none;
      font-size: 0.85rem;
    }

    .friendship-links a:hover {
      color: var(--accent-color);
    }

    .copyright {
      margin-top: 30px;
      text-align: center;
      color: #777777;
      font-size: 0.85rem;
      border-top: 1px solid #333333;
      padding-top: 20px;
    }

    .copyright a {
      color: #999;
      text-decoration: none;
    }

    /* Float Service Panel */
    .float-panel {
      position: fixed;
      right: 20px;
      bottom: 20px;
      z-index: 1001;
      display: flex;
      flex-direction: column;
      gap: 10px;
    }

    .float-item {
      background-color: var(--success-color);
      border: 2px solid var(--border-color);
      padding: 12px;
      border-radius: 50%;
      cursor: pointer;
      box-shadow: 3px 3px 0 var(--border-color);
      display: flex;
      align-items: center;
      justify-content: center;
      position: relative;
      transition: all 0.2s;
    }

    .float-item:hover {
      transform: scale(1.1);
    }

    .float-qr {
      position: absolute;
      right: 60px;
      bottom: 0;
      background-color: #fff;
      border: 2px solid var(--border-color);
      padding: 10px;
      border-radius: 6px;
      box-shadow: 4px 4px 0 var(--border-color);
      display: none;
      width: 150px;
    }

    .float-qr img {
      width: 100%;
      height: auto;
    }

    .float-item:hover .float-qr {
      display: block;
    }

    /* Responsive */
    @media (max-width: 992px) {
      .about-grid, .standards-grid {
        grid-template-columns: 1fr;
      }
      footer .ai-container {
        grid-template-columns: 1fr 1fr;
      }
      .mobile-menu-toggle {
        display: block;
      }
      .nav-menu {
        display: none;
        flex-direction: column;
        position: absolute;
        top: 100%;
        left: 0;
        width: 100%;
        background-color: #ffffff;
        border-bottom: var(--border-width) solid var(--border-color);
        padding: 20px;
        box-shadow: 0 4px 10px rgba(0,0,0,0.1);
      }
      .nav-menu.active {
        display: flex;
      }
      .hero-title {
        font-size: 2.2rem;
      }
    }

    @media (max-width: 768px) {
      footer .ai-container {
        grid-template-columns: 1fr;
      }
      .form-grid {
        grid-template-columns: 1fr;
      }
      .form-group.full-width {
        grid-column: span 1;
      }
    }