.iso-section-container {
        position: relative;
        border-radius: 0 0 20px 20px;
        border-top-left-radius: 150px;
        overflow: hidden;
        background: #7d7b79;
    }

    .image-overlay {
        position: absolute;
        top: 0;
        left: 0;
        width: 100%;
        height: 100%;
        background: linear-gradient(to bottom, rgba(0, 0, 0, 0.2) 0%, rgba(0, 0, 0, 0.8) 100%);
        pointer-events: none;
        transition: opacity 0.4s ease-in-out;
        opacity: 1;
        z-index: 2;
    }

    .iso-section-container:hover .image-overlay {
        opacity: 0;
    }

    .iso-section-container img {
        transition: transform 0.4s ease;
        display: block;
        width: 100%;
    }

    .iso-section-container:hover img {
        transform: scale(1.05);
    }

    .section-title {
        font-family: 'Georgia', serif;
        font-weight: 900;
        font-size: 3.5rem;
        line-height: 1.1;
    }

    .orange-label {
        color: #ff5e14;
        letter-spacing: 3px;
        font-weight: bold;
        text-transform: uppercase;
    }

    .feature-card {
        background-color: #f8f9fa;
        border-radius: 15px;
        padding: 30px;
        height: 100%;
    }

    .icon-circle {
        width: 60px;
        height: 60px;
        background-color: #ff5e14;
        border-radius: 50%;
        display: flex;
        align-items: center;
        justify-content: center;
        margin-bottom: 20px;
        color: white;
        font-size: 1.5rem;
    }

    /* Certificate gallery — presentation only; Bootstrap tabs and PDF loading stay unchanged. */
    .certificate-section {
        position: relative;
        isolation: isolate;
        overflow: hidden;
        min-height: 700px;
        padding: 3rem 0;
        background: url('/assets/img/banner-1.png') center/cover no-repeat;
        color: #062b5d;
        text-align: left;
    }

    .certificate-section::before,
    .certificate-section::after {
        content: '';
        position: absolute;
        z-index: 0;
        width: 290px;
        height: 290px;
        border: 1px solid rgba(255, 255, 255, .65);
        border-radius: 50%;
        pointer-events: none;
    }

    .certificate-section::before {
        top: -145px;
        left: -95px;
        box-shadow: 0 0 0 38px rgba(255, 255, 255, .26), 0 0 0 77px rgba(255, 255, 255, .13);
    }

    .certificate-section::after {
        right: -160px;
        bottom: -170px;
        box-shadow: 0 0 0 42px rgba(255, 255, 255, .2), 0 0 0 84px rgba(255, 255, 255, .1);
    }

    .certificate-section .overlay {
        position: absolute;
        inset: 0;
        z-index: 1;
        background: linear-gradient(90deg, rgba(255, 255, 255, .92) 0%, rgba(255, 255, 255, .78) 44%, rgba(255, 255, 255, .2) 74%, rgba(255, 255, 255, .08) 100%);
        pointer-events: none;
    }

    .certificate-section .certificate-content {
        position: relative;
        z-index: 2;
    }

    .certificate-section .iso-header {
        max-width: 320px;
        margin-bottom: 2.25rem !important;
        color: #062b5d !important;
        font-weight: 900;
        letter-spacing: -.025em;
    }

    .certificate-section .iso-header::after {
        content: '';
        display: block;
        width: 58px;
        height: 4px;
        margin-top: 1rem;
        border-radius: 99px;
        background: linear-gradient(90deg, #ffbd6c, #ff650d);
    }

    .certificate-section .nav-pills .nav-link {
        display: flex;
        flex-direction: row;
        flex-wrap: nowrap;
        align-items: center;
        min-height: 74px;
        height: auto;
        padding: 1rem 2.75rem 1rem 1.25rem;
        background: rgba(255, 255, 255, .94);
        color: #0b3769;
        border: 1px solid rgba(223, 229, 235, .92);
        border-radius: 13px;
        margin-bottom: 14px;
        justify-content: flex-start;
        text-align: left;
        letter-spacing: .02em;
        text-transform: none;
        box-shadow: 0 10px 22px rgba(25, 61, 90, .14);
        transition: transform .25s ease, background .25s ease, border-color .25s ease, box-shadow .25s ease;
        overflow: hidden;
    }

    .certificate-section .certificate-tab-icon {
        display: grid;
        width: 48px;
        height: 48px;
        place-items: center;
        flex: 0 0 48px;
        margin-right: 1rem;
        background: #1264b5;
        color: #fff;
        border-radius: 50%;
        font-size: 1.2rem;
        box-shadow: 0 7px 14px rgba(18, 100, 181, .22);
    }

    .certificate-section .certificate-tab:nth-child(2) .certificate-tab-icon { background: #219653; }
    .certificate-section .certificate-tab:nth-child(3) .certificate-tab-icon { background: #f36a10; }

    .certificate-section .certificate-tab-title {
        flex: 1;
        min-width: 0;
        font-size: 1.03rem;
        font-weight: 800;
        line-height: 1.35;
    }

    .certificate-section .certificate-tab-arrow {
        flex: 0 0 auto;
        margin-left: .75rem;
        font-size: 1.15rem;
        transition: transform .25s ease;
    }

    .certificate-section .nav-pills .nav-link:hover {
        color: #062b5d;
        background: #fff;
        border-color: rgba(255, 143, 45, .45);
        transform: translateX(5px);
        filter: none;
    }

    .certificate-section .nav-pills .nav-link.active {
        background: linear-gradient(135deg, #ff650c, #ff8e1f) !important;
        color: #fff !important;
        border: 1px solid transparent;
        box-shadow: 0 13px 28px rgba(235, 94, 18, .35);
        transform: translateX(7px);
    }

    .certificate-section .nav-pills .nav-link.active .certificate-tab-icon {
        background: #fff;
        color: #f36a10;
        box-shadow: 0 7px 14px rgba(122, 53, 6, .2);
    }

    .certificate-section .nav-pills .nav-link:hover .certificate-tab-arrow,
    .certificate-section .nav-pills .nav-link.active .certificate-tab-arrow {
        transform: translateX(4px);
    }

    .certificate-section .nav-pills .nav-link:focus-visible {
        outline: 3px solid #f36a10;
        outline-offset: 3px;
    }

    .certificate-section .a4-container {
        position: relative;
        width: min(100%, 610px);
        margin: 0 0 0 auto;
        aspect-ratio: 1 / 1.414;
        padding: 8px;
        background: #fff;
        border: 3px solid rgba(255, 255, 255, .9);
        border-radius: 8px;
        box-shadow: 0 20px 42px rgba(11, 44, 74, .28), 0 0 0 2px rgba(6, 43, 93, .65);
        overflow: hidden;
    }

    .certificate-section .a4-container iframe {
        width: 100%;
        height: 100%;
        border: 0;
        border-radius: 2px;
    }

    @media (max-width: 767.98px) {
        .certificate-section { min-height: 0; padding: 2rem 0 3rem; }
        .certificate-section .iso-header { margin-bottom: 1.5rem !important; }
        .certificate-section .nav-pills { margin-bottom: 2rem; }
        .certificate-section .nav-pills .nav-link.active,
        .certificate-section .nav-pills .nav-link:hover { transform: none; }
        .certificate-section .a4-container { margin: 0 auto; }
        .certificate-section::after { width: 210px; height: 210px; }
    }