body {
      font-family: 'Noto Sans TC', Arial, sans-serif;
      margin: 2em;
      background-color: #f8f9fa;
      color: #000000;
      line-height: 1.6;
        background: linear-gradient(135deg, #fffcf7, #d9d9d9);
        background-attachment: fixed;
    }
	header {
      background: linear-gradient(25deg, #4e54c8, #db8ffb);
      color: white;
      padding: 1.5em 1em;
      text-align: center;
      border-radius: 8px;
      margin-bottom: 2em;
      box-shadow: 0 2px 4px rgba(0,0,0,0.1);
    }
    .header-buttons {
    margin-top: 1em;
    display: flex;
    justify-content: center;
    gap: 1em;
    flex-wrap: wrap;
    }

    .header-btn {
    display: inline-block;
    padding: 0.5em 1.2em;
    background: rgba(255, 255, 255, 0.2);
    color: white;
    font-weight: bold;
    border: 1px solid rgba(255, 255, 255, 0.3);
    border-radius: 8px;
    text-decoration: none;
    backdrop-filter: blur(10px) saturate(180%);
    -webkit-backdrop-filter: blur(10px) saturate(180%);
    transition: background 0.3s, transform 0.2s, box-shadow 0.3s;
    }

    .header-btn:hover {
    background: rgba(255, 255, 255, 0.3);
    transform: scale(1.05);
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.2);
    }

    .filters {
      margin-bottom: 1.5em;
    }
    .filter-group {
      margin-bottom: 0.5em;
    }
    .filter-btn {
    margin: 0.3em;
    padding: 0.5em 1.2em;
    border: 1px solid rgba(255, 255, 255, 0.25);
    background: rgba(255, 255, 255, 0.58);
    backdrop-filter: blur(10px) saturate(180%);
    -webkit-backdrop-filter: blur(10px) saturate(180%);
    color: #000000;
    font-weight: 500;
    font-size: 16px;
    border-radius: 12px;
    cursor: pointer;
    transition: all 0.3s ease;
    box-shadow: 0 4px 16px rgba(0, 0, 0, 0.15);
    }
    .filter-btn:hover {
    background: rgba(255, 255, 255, 0.2);
    transform: scale(1.05);
    box-shadow: 0 6px 20px rgba(0, 0, 0, 0.25);
    }
    .filter-btn.active,
    .filter-btn:focus {
    background-image: linear-gradient(25deg, #4e54c8, #db8ffb);
    color: #fff;
    border-color: rgba(255, 255, 255, 0.4);
    transform: scale(1.07);
    box-shadow: 0 8px 24px rgba(0, 0, 0, 0.3);
    }
	#cards {
		display: flex;
		flex-wrap: wrap;
		gap: 1em;
	  }
    .card {
        background: rgba(255, 255, 255, 0.559); /* 半透明白 */
        backdrop-filter: blur(20px) saturate(180%);
        -webkit-backdrop-filter: blur(20px) saturate(180%);
        border-radius: 8px;
        border: 1px solid rgba(255, 255, 255, 0.881);
        box-shadow: 0 8px 32px rgba(0, 0, 0, 0.25);
        padding: 1.5em;
        color: #000000;
        transition: transform 0.3s ease, box-shadow 0.3s ease;
        flex: 1 1 100%;
        box-sizing: border-box;
    }
	  @media(min-width: 800px){
		  .card{
			  flex: 1 1 calc(50% - 1em);
		  }
	  }
    .hidden {
      display: none;
    }
    .card:hover {
        transform: scale(1.02);
        box-shadow: 0 12px 36px rgba(0,0,0,0.3);
    }
    .card h3.card-heading {
        position: relative;
        font-weight: bold;
        margin-bottom: 0.5em;
        padding-right: 5em; /* 給編號留空間 */
        word-wrap: break-word;
        word-break: break-word;
        line-height: 1.4;
    }
    .card h3.card-heading .card-id {
        position: absolute;
        right: 0.2em;
        top: 0.2em;
        font-size: 0.85em;
        color: #888;
        font-style: italic;
        font-weight: normal;
        white-space: nowrap;
    }
    @media (max-width: 480px) {
    .card h3.card-heading {
        font-size: 1em;
        line-height: 1.3;
        padding-right: 4em;
    }

    .card h3.card-heading .card-id {
        font-size: 0.8em;
        top: 0.1em;
        right: 0.1em;
    }
    }
    .exam-IELTS { color: #d63384; font-weight: bold; }
    .exam-TOEFL { color: #6610f2; font-weight: bold; }
    .exam-TOEIC { color: #20c997; font-weight: bold; }
    .exam-BESTEP { color: #fd7e14; font-weight: bold; }
    .exam-GEPT { color: #17a2b8; font-weight: bold; }
    .level-C2 { color: #4b0082; font-weight: bold; }
    .level-C1 { color: #1e90ff; font-weight: bold; }
    .level-B2 { color: #28a745; font-weight: bold; }
    .level-B1 { color: #ffc107; font-weight: bold; }
    .level-A2, .level-A1 { color: #dc3545; font-weight: bold; }

    #back-to-top {
        position: fixed;
        bottom: 30px;
        right: 30px;
        z-index: 99;
        width: 40px;
        height: 40px;
        font-size: 20px;
        font-weight: bold;
        color: #1f1f1f;
        background-color: rgba(208, 208, 208, 0.547);
        backdrop-filter: blur(10px) saturate(180%);
        -webkit-backdrop-filter: blur(10px) saturate(180%);
        border: none;
        border-radius: 50%;
        cursor: pointer;
        display: none;
        padding: 0;
        display: flex;
        align-items: center;
        justify-content: center;
        transition: opacity 0.3s, transform 0.3s;
        }

    #back-to-top:hover {
    transform: scale(1.1);
    background-color: rgba(208, 208, 208, 0.8);
    }
        @media screen and (max-width: 768px) {
        #back-to-top {
            width: 36px;
            height: 36px;
            font-size: 18px;
        }
        }
    #popup-overlay {
        position: fixed;
        top: 0;
        left: 0;
        width: 100%;
        height: 100%;
        background-color: rgba(0, 0, 0, 0.6);
        backdrop-filter: blur(5px);
        display: flex;
        align-items: center;
        justify-content: center;
        z-index: 9999;
        }

    #popup-content {
        position: relative;
        background-color: transparent;
        border-radius: 10px;
        overflow: hidden;
        max-width: 90%;
        max-height: 90%;
    }

    #popup-content img {
        display: block;
        max-width: 100%;
        height: auto;
        border-radius: 8px;
    }

    #popup-close {
        position: absolute;
        top: 10px;
        right: 10px;
        width: 32px;
        height: 32px;
        padding: 0;
        font-size: 18px;
        font-weight: bold;
        background-color: rgba(0, 0, 0, 0.7);
        color: white;
        border: none;
        border-radius: 50%;
        cursor: pointer;
        display: flex;
        align-items: center;
        justify-content: center;
        }
    #popup-content {
        opacity: 0;
        transform: scale(0.8);
        animation: popupIn 0.5s ease-out forwards;
    }

    @keyframes popupIn {
    to {
        opacity: 1;
        transform: scale(1);
    }
    }
        /* 預設情況：桌機顯示，手機隱藏 */
    .ad-desktop {
    display: block;
    }
    .ad-mobile {
    display: none;
    }

    /* 小螢幕情況下：手機顯示，桌機隱藏 */
    @media screen and (max-width: 768px) {
    .ad-desktop {
        display: none;
    }
    .ad-mobile {
        display: block;
    }
    }