/* RESET & GLOBAL */
    * {
        margin: 0;
        padding: 0;
        box-sizing: border-box;
    }

    body {
        background: #f5f7fa;
        font-family: system-ui, -apple-system, 'Segoe UI', Roboto, 'Helvetica Neue', sans-serif;
        line-height: 1.5;
        padding: 40px 20px;
    }

    .case-study {
        max-width: 1100px;
        margin: 0 auto;
        background: #ffffff;
        border-radius: 24px;
        box-shadow: 0 20px 35px -12px rgba(0,0,0,0.08);
        padding: 32px 28px;
    }

    .case-study h1 {
        font-size: 28px;
        font-weight: 700;
        letter-spacing: -0.01em;
        margin-bottom: 16px;
        color: #0a2540;
        border-left: 5px solid #0066cc;
        padding-left: 20px;
    }

    .case-study p,
    .case-study li,
    .case-study span {
        font-size: 16px;
        line-height: 1.6;
        color: #2c3e44;
    }

    .case-study .section {
        margin-bottom: 48px;
    }

    .case-study ul {
        margin: 16px 0 8px 28px;
    }

    .case-study li {
        margin: 8px 0;
    }

    /* 两张卡片并列布局 */
    .cards-row {
        display: flex;
        flex-wrap: wrap;
        gap: 30px;
        margin: 28px 0 24px 0;
    }

    .product-full-card {
        flex: 1;
        min-width: 280px;
        background: #ffffff;
        border-radius: 20px;
        box-shadow: 0 8px 20px rgba(0,0,0,0.05), 0 2px 4px rgba(0,0,0,0.02);
        border: 1px solid #eef2f8;
        transition: all 0.2s ease;
        overflow: hidden;
    }

    .product-image-box {
        width: 100%;
        height: 280px;
        background: #f8fafc;
        display: flex;
        align-items: center;
        justify-content: center;
        overflow: hidden;
        position: relative;
    }

    .product-image-box img {
        width: 100%;
        height: 100%;
        object-fit: cover;
        display: block;
        transition: transform 0.2s ease;
    }

    .zoom-btn {
        position: absolute;
        bottom: 12px;
        right: 12px;
        background: rgba(0,0,0,0.65);
        color: white;
        border: none;
        border-radius: 30px;
        width: 36px;
        height: 36px;
        font-size: 18px;
        cursor: pointer;
        display: flex;
        align-items: center;
        justify-content: center;
        transition: all 0.2s;
        backdrop-filter: blur(4px);
        z-index: 10;
    }
    .zoom-btn:hover {
        background: #0066cc;
        transform: scale(1.05);
    }

    .product-content {
        padding: 18px 20px;
    }

    .product-content strong {
        display: block;
        margin-bottom: 12px;
        font-size: 16px;
        font-weight: 600;
    }

    .product-content strong a {
        font-weight: 600;
        font-size: 16px;
        color: #0066cc;
        text-decoration: none;
    }

    .product-content strong a:hover {
        text-decoration: underline;
    }

    .product-content p {
        margin: 8px 0;
        line-height: 1.45;
    }

    .product-content a {
        color: #0066cc;
        text-decoration: none;
        transition: color 0.2s;
    }

    .product-content a:hover {
        text-decoration: underline;
        color: #004c99;
    }

    .product-full-card:hover {
        transform: translateY(-4px);
        box-shadow: 0 14px 28px rgba(0,0,0,0.08);
        border-color: #dce5ef;
    }

    @media (max-width: 700px) {
        .cards-row {
            flex-direction: column;
            gap: 20px;
        }
        .case-study {
            padding: 20px 18px;
        }
    }

    .cta {
        display: inline-block;
        margin-top: 24px;
        padding: 12px 28px;
        background: #0066cc;
        color: #fff;
        text-decoration: none;
        border-radius: 40px;
        font-weight: 500;
        font-size: 16px;
        transition: background 0.2s;
        box-shadow: 0 2px 6px rgba(0,102,204,0.2);
        border: none;
        cursor: pointer;
    }
    .cta:hover {
        background: #004d99;
        text-decoration: none;
    }

    /* Lightbox Modal */
    .image-modal {
        display: none;
        position: fixed;
        top: 0;
        left: 0;
        width: 100%;
        height: 100%;
        background-color: rgba(0, 0, 0, 0.92);
        z-index: 9999;
        justify-content: center;
        align-items: center;
        cursor: pointer;
        backdrop-filter: blur(6px);
    }

    .image-modal.active {
        display: flex;
        animation: fadeIn 0.2s ease;
    }

    .modal-img {
        max-width: 90%;
        max-height: 90%;
        object-fit: contain;
        border-radius: 12px;
        box-shadow: 0 20px 40px rgba(0,0,0,0.4);
    }

    .modal-close {
        position: absolute;
        top: 28px;
        right: 40px;
        font-size: 48px;
        font-weight: 300;
        color: white;
        cursor: pointer;
        background: transparent;
        border: none;
        line-height: 1;
    }
    .modal-close:hover {
        transform: scale(1.1);
        color: #ddd;
    }

    @keyframes fadeIn {
        from { opacity: 0; }
        to { opacity: 1; }
    }