body.viewer-page {
    margin: 0;
    background: #0a0a0d;
    color: #ffffff;
    font-family:
        "Noto Sans JP",
        "Hiragino Kaku Gothic ProN",
        "Yu Gothic",
        "Meiryo",
        system-ui,
        sans-serif;
    overflow: hidden;
}

.viewer-back {
    position: fixed;
    top: 18px;
    left: 18px;
    z-index: 30;
    padding: 10px 16px;
    text-decoration: none;
    color: #ffffff;
    background: rgba(20, 20, 24, 0.55);
    border: 1px solid rgba(255,255,255,0.14);
    border-radius: 999px;
    backdrop-filter: blur(8px);
    transition: background 0.2s ease, transform 0.2s ease;
}

.viewer-back:hover {
    background: rgba(255,255,255,0.12);
    transform: translateY(-1px);
}

.viewer-shell {
    position: relative;
    width: 100vw;
    height: 100vh;
    overflow: hidden;
}

.viewer-image-wrap {
    width: 100%;
    height: 100%;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 70px 90px 90px;
    box-sizing: border-box;
    text-align: center;
}

.viewer-image {
    max-width: calc(100vw - 180px);
    max-height: calc(100vh - 160px);
    width: auto;
    height: auto;
    object-fit: contain;
    box-shadow: 0 18px 60px rgba(0,0,0,0.45);
    border-radius: 10px;
    cursor: zoom-in;
    display: block;
    margin: 0 auto;
}

.viewer-image.fullsize {
    max-width: none;
    max-height: none;
    cursor: zoom-out;
    display: block;
    margin: 0 auto;
}

/* Floating arrow buttons */
.viewer-nav {
    position: fixed;
    top: 50%;
    transform: translateY(-50%);
    z-index: 25;

    width: 56px;
    height: 56px;
    display: flex;
    align-items: center;
    justify-content: center;

    text-decoration: none;
    font-size: 30px;
    line-height: 1;
    color: #ffffff;

    background: rgba(20, 20, 24, 0.42);
    border: 1px solid rgba(255,255,255,0.12);
    border-radius: 999px;
    backdrop-filter: blur(10px);
    box-shadow: 0 8px 30px rgba(0,0,0,0.25);

    transition:
        background 0.2s ease,
        transform 0.2s ease,
        box-shadow 0.2s ease;
}

.viewer-nav:hover {
    background: rgba(255,255,255,0.14);
    box-shadow: 0 12px 36px rgba(0,0,0,0.35);
}

.viewer-prev {
    left: 18px;
}

.viewer-next {
    right: 18px;
}

.viewer-prev:hover {
    transform: translateY(-50%) scale(1.06);
}

.viewer-next:hover {
    transform: translateY(-50%) scale(1.06);
}

.viewer-filename {
    position: fixed !important;
    left: 50% !important;
    bottom: 18px !important;
    top: auto !important;
    right: auto !important;
    transform: translateX(-50%) !important;
    z-index: 9999 !important;

    display: inline-block !important;
    margin: 0 !important;
    padding: 8px 14px !important;
    max-width: calc(100vw - 40px) !important;

    background: rgba(20, 20, 24, 0.72) !important;
    border: 1px solid rgba(255,255,255,0.14) !important;
    border-radius: 999px !important;
    box-shadow: 0 8px 24px rgba(0,0,0,0.28) !important;

    color: #d8d8d8 !important;
    font-size: 13px !important;
    line-height: 1.2 !important;
    white-space: nowrap !important;
    overflow: hidden !important;
    text-overflow: ellipsis !important;

    backdrop-filter: blur(8px) !important;
}