body, html {
    margin: 0;
    padding: 0;
    font-family: 'Inter', 'Segoe UI', 'PingFang SC', 'Hiragino Sans', Arial, sans-serif;
    background: transparent;
    min-height: 100vh;
    color: #222;
    box-sizing: border-box;
    position: relative;
    overflow-x: hidden;
  }
  
  .bg-gradient {
    position: fixed;
    z-index: -2;
    width: 100vw;
    height: 100vh;
    background: linear-gradient(120deg, #6f9cf7 0%, #3a8dde 60%, #a7e8f7 100%);
    top: 0; left: 0;
  }
  
  .bg-blur {
    position: fixed;
    z-index: -1;
    width: 100vw;
    height: 100vh;
    pointer-events: none;
    top: 0; left: 0;
    background: radial-gradient(circle at 20% 30%, #fff6 0%, #fff0 60%),
                radial-gradient(circle at 80% 70%, #b6e0ff55 0%, #fff0 70%);
    filter: blur(60px);
  }
  
  header {
    padding: 0;
    background: transparent;
    width: 100%;
    margin-bottom: 0;
  }
  
  .header-inner {
    max-width: 820px;
    margin: 0 auto;
    padding: 48px 16px 0 16px;
    display: flex;
    flex-direction: column;
    align-items: center;
  }
  
  .logo {
    display: flex;
    align-items: center;
    font-size: 2.4rem;
    font-weight: bold;
    color: #fff;
    margin-bottom: 18px;
    letter-spacing: 2px;
    text-shadow: 0 2px 12px rgba(60,120,255,0.18);
    gap: 14px;
    user-select: none;
  }
  .logo-icon {
    display: flex;
    align-items: center;
    margin-right: 8px;
    filter: drop-shadow(0 2px 8px #6f9cf7aa);
  }
  .logo-text {
    font-family: 'Inter', 'Segoe UI', 'PingFang SC', 'Hiragino Sans', Arial, sans-serif;
    font-weight: 800;
    font-size: 2.1rem;
    letter-spacing: 2px;
    color: #fff;
    text-shadow: 0 2px 12px rgba(60,120,255,0.18);
  }
  
  .header-desc h1 {
    margin: 0 0 6px 0;
    color: #fff;
    font-size: 1.5rem;
    font-weight: 700;
    text-shadow: 0 2px 8px rgba(60,120,255,0.10);
    letter-spacing: 1px;
  }
  .header-desc p {
    margin: 0 0 18px 0;
    color: #eaf6ff;
    font-size: 1.08rem;
    font-weight: 400;
    letter-spacing: 0.5px;
  }
  
  .search-bar {
    width: 100%;
    max-width: 420px;
    margin: 0 0 8px 0;
    position: relative;
  }
  .search-bar input {
    width: 100%;
    padding: 12px 20px 12px 38px;
    border-radius: 28px;
    border: none;
    font-size: 1.08rem;
    background: rgba(255,255,255,0.92);
    box-shadow: 0 2px 16px rgba(60,120,255,0.10);
    outline: none;
    transition: box-shadow 0.2s, background 0.2s;
    color: #2a3a4a;
  }
  .search-bar input:focus {
    box-shadow: 0 4px 24px rgba(60,120,255,0.18);
    background: #fff;
  }
  .search-bar input::placeholder {
    color: #b0c8e8;
    font-size: 1.05rem;
  }
  
  .platform-info {
    background: rgba(255,255,255,0.75);
    border-radius: 22px;
    margin: 32px auto 18px auto;
    max-width: 700px;
    padding: 28px 36px;
    box-shadow: 0 2px 24px rgba(60,120,255,0.10);
    backdrop-filter: blur(8px);
    border: 1.5px solid #e3eefd;
  }
  .platform-info h2 {
    margin-top: 0;
    color: #3a8dde;
    font-size: 1.18rem;
    font-weight: 700;
  }
  .platform-info ul {
    margin: 0;
    padding-left: 20px;
    color: #444;
    font-size: 1.05rem;
    line-height: 1.8;
  }
  
  .filters {
    display: flex;
    justify-content: center;
    margin: 18px 0 10px 0;
  }
  #categoryFilters {
    display: flex;
    flex-wrap: wrap;
    gap: 12px;
  }
  .filter-btn {
    background: linear-gradient(90deg, #eaf6ff 60%, #f7faff 100%);
    color: #3a8dde;
    border: 2px solid #e3eefd;
    border-radius: 22px;
    padding: 7px 22px;
    font-size: 1.05rem;
    font-weight: 600;
    cursor: pointer;
    transition: background 0.18s, color 0.18s, box-shadow 0.18s, border 0.18s;
    margin-bottom: 4px;
    outline: none;
    box-shadow: 0 2px 8px rgba(60,120,255,0.06);
    letter-spacing: 1px;
    position: relative;
    overflow: hidden;
  }
  .filter-btn.active, .filter-btn:hover {
    background: linear-gradient(90deg, #3a8dde 60%, #6f9cf7 100%);
    color: #fff;
    box-shadow: 0 4px 16px rgba(60,120,255,0.13);
    border-color: #3a8dde;
  }
  .filter-btn:active {
    transform: scale(0.97);
  }
  
  .loading {
    text-align: center;
    color: #3a8dde;
    font-size: 1.2rem;
    margin: 40px 0;
    letter-spacing: 2px;
    opacity: 0.8;
    animation: fadein 1.2s infinite alternate;
  }
  @keyframes fadein {
    from { opacity: 0.5; }
    to { opacity: 1; }
  }
  
  .card-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(340px, 1fr));
    gap: 32px;
    max-width: 1200px;
    margin: 0 auto 48px auto;
    padding: 0 18px;
  }
  
  .card {
    background: rgba(255,255,255,0.82);
    border-radius: 22px;
    box-shadow: 0 4px 32px rgba(60,120,255,0.13);
    padding: 28px 24px 20px 24px;
    display: flex;
    flex-direction: column;
    transition: box-shadow 0.22s, transform 0.22s, background 0.22s;
    cursor: pointer;
    position: relative;
    min-height: 180px;
    border: 1.5px solid #e3eefd;
    backdrop-filter: blur(6px);
    overflow: hidden;
    animation: cardfadein 0.7s;
  }
  @keyframes cardfadein {
    from { opacity: 0; transform: translateY(30px) scale(0.98);}
    to { opacity: 1; transform: translateY(0) scale(1);}
  }
  .card:hover {
    box-shadow: 0 12px 48px rgba(60,120,255,0.18);
    transform: translateY(-6px) scale(1.025);
    background: rgba(255,255,255,0.95);
    border-color: #b6e0ff;
  }
  .card .card-title {
    font-size: 1.18rem;
    font-weight: 700;
    color: #3a8dde;
    margin-bottom: 6px;
    letter-spacing: 1px;
  }
  .card .card-author {
    font-size: 0.99rem;
    color: #6f9cf7;
    margin-bottom: 8px;
    font-weight: 600;
  }
  .card .card-desc {
    font-size: 1.01rem;
    color: #444;
    margin-bottom: 12px;
    min-height: 36px;
    line-height: 1.7;
  }
  .card .card-meta {
    display: flex;
    flex-wrap: wrap;
    gap: 14px;
    font-size: 0.97rem;
    color: #666;
    margin-bottom: 10px;
  }
  .card .card-meta span {
    background: #f2f7ff;
    border-radius: 12px;
    padding: 2px 12px;
    font-weight: 500;
  }
  .card .card-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 10px;
    margin-bottom: 0;
  }
  .card .card-tag {
    background: linear-gradient(90deg, #3a8dde 60%, #6f9cf7 100%);
    color: #fff;
    border-radius: 10px;
    padding: 2px 12px;
    font-size: 0.91rem;
    margin-bottom: 2px;
    font-weight: 500;
    letter-spacing: 0.5px;
    box-shadow: 0 1px 4px #6f9cf733;
  }
  
  footer {
    background: rgba(255,255,255,0.85);
    border-top-left-radius: 18px;
    border-top-right-radius: 18px;
    box-shadow: 0 -2px 12px rgba(60,120,255,0.08);
    padding: 28px 0 14px 0;
    text-align: center;
    margin-top: 36px;
    backdrop-filter: blur(4px);
  }
  footer .links {
    margin-bottom: 8px;
  }
  footer .links a {
    color: #3a8dde;
    margin: 0 12px;
    text-decoration: none;
    font-weight: 600;
    transition: color 0.2s;
    font-size: 1.08rem;
  }
  footer .links a:hover {
    color: #6f9cf7;
  }
  footer .copyright {
    color: #888;
    font-size: 1.01rem;
    letter-spacing: 1px;
  }
  
  @media (max-width: 900px) {
    .header-inner { padding-top: 32px; }
    .platform-info { padding: 18px 8px; }
    .card-grid { gap: 18px; padding: 0 4px; }
    .card { padding: 16px 10px 12px 10px; }
  }
  @media (max-width: 600px) {
    .header-inner { padding-top: 18px; }
    .logo-text { font-size: 1.3rem; }
    .platform-info { margin: 18px auto 10px auto; }
    .card-grid { grid-template-columns: 1fr; }
  }

  .qrcode-fab {
    position: fixed;
    right: 28px;
    bottom: 32px;
    z-index: 99;
    width: 56px;
    height: 56px;
    background: linear-gradient(135deg, #3a8dde 60%, #6f9cf7 100%);
    border-radius: 50%;
    box-shadow: 0 4px 24px #3a8dde44;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    transition: box-shadow 0.18s, transform 0.18s;
    animation: fabin 0.7s;
  }
  .qrcode-fab:hover {
    box-shadow: 0 8px 32px #3a8dde66;
    transform: scale(1.08);
  }
  @keyframes fabin {
    from { opacity: 0; transform: scale(0.7);}
    to { opacity: 1; transform: scale(1);}
  }

  .qrcode-fab svg {
    width: 28px;
    height: 28px;
  }

  .qrcode-modal {
    display: none;
    position: fixed;
    z-index: 100;
    left: 0; top: 0; width: 100vw; height: 100vh;
    background: rgba(30,40,60,0.18);
    align-items: center;
    justify-content: center;
    animation: fadein 0.3s;
  }
  .qrcode-modal.active {
    display: flex;
  }
  .qrcode-card {
    background: rgba(255,255,255,0.98);
    border-radius: 22px;
    box-shadow: 0 8px 48px #3a8dde33;
    padding: 32px 28px 24px 28px;
    max-width: 98vw;
    text-align: center;
    position: relative;
    animation: cardfadein 0.5s;
  }
  .qrcode-close {
    position: absolute;
    right: 18px; top: 12px;
    background: none;
    border: none;
    font-size: 2rem;
    color: #3a8dde;
    cursor: pointer;
    font-weight: bold;
    transition: color 0.18s;
  }
  .qrcode-close:hover { color: #f55; }
  .qrcode-img {
    width: 320px;
    height: auto;
    max-width: 90vw;
    border-radius: 16px;
    margin-bottom: 18px;
    box-shadow: 0 2px 16px #3a8dde22;
    background: #fff;
  }
  .qrcode-desc {
    color: #3a8dde;
    font-size: 1.08rem;
    margin-bottom: 8px;
    line-height: 1.7;
  }
  @media (max-width: 600px) {
    .qrcode-card { padding: 10px 2px 8px 2px; }
    .qrcode-img { width: 220px; max-width: 98vw; }
    .qrcode-fab { right: 16px; bottom: 16px; width: 48px; height: 48px; }
  }

  .footer-contact {
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: 10px;
    gap: 10px;
  }
  .footer-qrcode {
    width: 64px;
    height: 64px;
    border-radius: 12px;
    box-shadow: 0 2px 8px #3a8dde22;
    cursor: pointer;
    transition: box-shadow 0.18s, transform 0.18s;
    background: #fff;
  }
  .footer-qrcode:hover {
    box-shadow: 0 4px 16px #3a8dde44;
    transform: scale(1.08);
  }
  .footer-contact-text {
    color: #3a8dde;
    font-size: 1.08rem;
    font-weight: 600;
    cursor: pointer;
    transition: color 0.18s;
  }
  .footer-contact-text:hover { color: #6f9cf7; }