.pdfmerge-tool {
    --pdfmerge-line: rgba(29, 29, 31, 0.09);
    --pdfmerge-soft: rgba(255, 255, 255, 0.78);
    --pdfmerge-danger: #c92a2a;
    --pdfmerge-ok: #0a7f55;
    padding-bottom: 5.5rem;
}

.pdfmerge-shell,
.pdfmerge-workspace,
.pdfmerge-files,
.pdfmerge-pages,
.pdfmerge-sidebar,
.pdfmerge-settings-card,
.pdfmerge-advanced {
    display: grid;
    gap: 1rem;
}

.pdfmerge-file-input {
    position: absolute;
    width: 1px;
    height: 1px;
    opacity: 0;
    pointer-events: none;
}

.pdfmerge-header {
    display: grid;
    gap: 1rem;
    padding: 1rem;
    border: 1px solid var(--pdfmerge-line);
    border-radius: var(--radius-lg);
    background: linear-gradient(135deg, rgba(255, 255, 255, 0.95), rgba(241, 247, 255, 0.78));
    box-shadow: var(--shadow-card);
}

.pdfmerge-kicker {
    margin: 0 0 0.4rem;
    color: var(--accent);
    font-size: 0.78rem;
    font-weight: 800;
    text-transform: uppercase;
}

.pdfmerge-header h2,
.pdfmerge-result h3,
.pdfmerge-section-head h3,
.pdfmerge-settings-card h3 {
    margin: 0;
    letter-spacing: 0;
}

.pdfmerge-header h2 {
    font-size: clamp(1.55rem, 7vw, 2.6rem);
    line-height: 1;
}

.pdfmerge-header p,
.pdfmerge-status,
.pdfmerge-section-head p,
.pdfmerge-setting-row,
.pdfmerge-toggle small,
.pdfmerge-page-meta,
.pdfmerge-file-meta,
.pdfmerge-action-bar span,
.pdfmerge-result p {
    margin: 0;
    color: var(--text-secondary);
}

.pdfmerge-trust {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
    padding: 0;
    margin: 0;
    list-style: none;
}

.pdfmerge-trust li {
    min-height: 2rem;
    padding: 0.45rem 0.7rem;
    border: 1px solid rgba(0, 122, 255, 0.14);
    border-radius: 999px;
    background: rgba(255, 255, 255, 0.76);
    color: var(--text-primary);
    font-size: 0.82rem;
    font-weight: 700;
}

.pdfmerge-layout {
    display: grid;
    gap: 1rem;
}

.pdfmerge-dropzone,
.pdfmerge-files,
.pdfmerge-pages,
.pdfmerge-result,
.pdfmerge-settings-card,
.pdfmerge-file-card,
.pdfmerge-page-card {
    border: 1px solid var(--pdfmerge-line);
    border-radius: var(--radius-lg);
    background: var(--pdfmerge-soft);
    box-shadow: var(--shadow-card);
}

.pdfmerge-dropzone {
    display: grid;
    justify-items: center;
    gap: 0.55rem;
    width: 100%;
    min-height: 15rem;
    padding: 1.4rem;
    text-align: center;
    color: var(--text-primary);
    transition: transform 0.2s ease, border-color 0.2s ease, background 0.2s ease, box-shadow 0.2s ease;
}

.pdfmerge-dropzone:hover,
.pdfmerge-dropzone.is-dragover {
    transform: translateY(-1px);
    border-color: rgba(0, 122, 255, 0.32);
    background: rgba(255, 255, 255, 0.95);
    box-shadow: var(--shadow-soft);
}

.pdfmerge-drop-icon {
    display: grid;
    place-items: center;
    width: 4.4rem;
    height: 5.3rem;
    border-radius: 0.9rem;
    background: linear-gradient(145deg, #ff5f57, #ffbd2e);
    color: #fff;
    font-weight: 900;
    box-shadow: 0 18px 34px rgba(255, 95, 87, 0.22);
}

.pdfmerge-dropzone strong {
    font-size: clamp(1.2rem, 5vw, 1.55rem);
}

.pdfmerge-dropzone small {
    color: var(--text-secondary);
}

.pdfmerge-status {
    min-height: 1.5rem;
    padding: 0 0.25rem;
}

.pdfmerge-files,
.pdfmerge-pages,
.pdfmerge-result,
.pdfmerge-settings-card {
    padding: 1rem;
}

.pdfmerge-section-head {
    display: flex;
    align-items: flex-start;
    justify-content: space-between;
    gap: 1rem;
}

.pdfmerge-file-list {
    display: grid;
    gap: 0.75rem;
}

.pdfmerge-file-card {
    display: grid;
    grid-template-columns: auto minmax(0, 1fr) auto;
    align-items: center;
    gap: 0.75rem;
    padding: 0.8rem;
    background: rgba(255, 255, 255, 0.86);
}

.pdfmerge-file-grip,
.pdfmerge-page-grip {
    display: grid;
    place-items: center;
    width: 2.4rem;
    height: 2.4rem;
    border-radius: 999px;
    color: var(--text-secondary);
    cursor: grab;
}

.pdfmerge-file-name,
.pdfmerge-page-title {
    overflow: hidden;
    margin: 0;
    text-overflow: ellipsis;
    white-space: nowrap;
    font-weight: 800;
}

.pdfmerge-icon-button,
.pdfmerge-toolbar button,
.pdfmerge-ghost-button {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    min-height: 2.55rem;
    padding: 0.55rem 0.75rem;
    border: 1px solid var(--pdfmerge-line);
    border-radius: 999px;
    background: rgba(255, 255, 255, 0.9);
    color: var(--text-primary);
    font-weight: 750;
    transition: transform 0.18s ease, background 0.18s ease, color 0.18s ease;
}

.pdfmerge-icon-button:hover,
.pdfmerge-toolbar button:hover,
.pdfmerge-ghost-button:hover {
    transform: translateY(-1px);
    background: #fff;
}

.pdfmerge-page-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(9.25rem, 1fr));
    gap: 0.8rem;
    contain: layout paint;
}

.pdfmerge-page-card {
    position: relative;
    display: grid;
    gap: 0.65rem;
    min-width: 0;
    padding: 0.7rem;
    background: rgba(255, 255, 255, 0.88);
    transition: transform 0.2s ease, border-color 0.2s ease, box-shadow 0.2s ease;
}

.pdfmerge-page-card.is-selected {
    border-color: rgba(0, 122, 255, 0.42);
    box-shadow: 0 0 0 4px rgba(0, 122, 255, 0.1);
}

.pdfmerge-page-card.is-dragging {
    opacity: 0.58;
}

.pdfmerge-page-preview {
    position: relative;
    display: grid;
    place-items: center;
    aspect-ratio: 0.72;
    overflow: hidden;
    border: 1px solid rgba(29, 29, 31, 0.08);
    border-radius: var(--radius-sm);
    background: linear-gradient(180deg, #fff, #f4f7fb);
}

.pdfmerge-page-preview canvas,
.pdfmerge-page-preview img {
    width: 100%;
    height: 100%;
    object-fit: contain;
    transform: rotate(var(--page-rotation, 0deg));
    transition: transform 0.18s ease;
}

.pdfmerge-page-skeleton {
    width: 64%;
    height: 78%;
    border-radius: 0.45rem;
    background: linear-gradient(90deg, #eef2f7, #ffffff, #eef2f7);
    background-size: 220% 100%;
    animation: pdfmerge-shimmer 1.5s infinite;
}

.pdfmerge-page-actions {
    display: grid;
    grid-template-columns: repeat(4, minmax(0, 1fr));
    gap: 0.4rem;
}

.pdfmerge-page-actions button {
    min-width: 0;
    min-height: 2.35rem;
    padding: 0.35rem;
    border: 1px solid var(--pdfmerge-line);
    border-radius: 0.75rem;
    background: rgba(255, 255, 255, 0.9);
    font-weight: 800;
}

.pdfmerge-page-actions button:hover {
    background: #fff;
}

.pdfmerge-page-select {
    position: absolute;
    top: 0.85rem;
    left: 0.85rem;
    z-index: 2;
    width: 1.2rem;
    height: 1.2rem;
    padding: 0;
    accent-color: var(--accent);
}

.pdfmerge-toolbar {
    display: flex;
    flex-wrap: wrap;
    gap: 0.45rem;
    justify-content: flex-end;
}

.pdfmerge-settings-card {
    align-self: start;
}

.pdfmerge-settings-card select {
    width: 100%;
    min-height: 3.1rem;
    border: 1px solid var(--border);
    border-radius: var(--radius-sm);
    padding: 0.85rem 1rem;
    background: rgba(255, 255, 255, 0.92);
    color: var(--text-primary);
    font: inherit;
}

.pdfmerge-setting-row {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 1rem;
    min-height: 3.1rem;
    padding: 0.75rem 0.9rem;
    border: 1px solid var(--pdfmerge-line);
    border-radius: var(--radius-sm);
    background: rgba(255, 255, 255, 0.78);
}

.pdfmerge-toggle {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 1rem;
    padding: 0.9rem;
    border: 1px solid var(--pdfmerge-line);
    border-radius: var(--radius-sm);
    background: rgba(255, 255, 255, 0.78);
    cursor: pointer;
}

.pdfmerge-toggle span:first-child {
    display: grid;
    gap: 0.2rem;
}

.pdfmerge-advanced-checkbox {
    position: absolute;
    opacity: 0;
    pointer-events: none;
}

.pdfmerge-switch {
    position: relative;
    width: 3.35rem;
    height: 1.95rem;
    flex: 0 0 auto;
    border-radius: 999px;
    background: rgba(120, 120, 128, 0.22);
    transition: background 0.2s ease;
}

.pdfmerge-switch span {
    position: absolute;
    top: 0.18rem;
    left: 0.18rem;
    width: 1.58rem;
    height: 1.58rem;
    border-radius: 50%;
    background: #fff;
    box-shadow: 0 6px 16px rgba(15, 23, 42, 0.18);
    transition: transform 0.2s ease;
}

.pdfmerge-advanced-checkbox:checked + .pdfmerge-toggle .pdfmerge-switch {
    background: var(--accent);
}

.pdfmerge-advanced-checkbox:checked + .pdfmerge-toggle .pdfmerge-switch span {
    transform: translateX(1.38rem);
}

.pdfmerge-advanced {
    max-height: 0;
    opacity: 0;
    overflow: hidden;
    visibility: hidden;
    transform: translateY(-0.4rem);
    transition: max-height 0.28s ease, opacity 0.2s ease, transform 0.2s ease, visibility 0.2s ease;
}

.pdfmerge-advanced[aria-hidden="false"] {
    max-height: 120rem;
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
}

.pdfmerge-check {
    display: flex;
    align-items: center;
    gap: 0.7rem;
    min-height: 3rem;
    padding: 0.75rem 0.9rem;
    border: 1px solid var(--pdfmerge-line);
    border-radius: var(--radius-sm);
    background: rgba(255, 255, 255, 0.78);
    font-weight: 750;
}

.pdfmerge-check input {
    width: 1.05rem;
    height: 1.05rem;
    margin: 0;
    accent-color: var(--accent);
}

.pdfmerge-result {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 1rem;
    background: linear-gradient(135deg, rgba(232, 250, 242, 0.95), rgba(255, 255, 255, 0.9));
}

.pdfmerge-result-actions {
    display: grid;
    gap: 0.6rem;
    width: 100%;
}

.pdfmerge-action-bar {
    position: fixed;
    right: 1rem;
    bottom: 1rem;
    left: 1rem;
    z-index: 15;
    display: grid;
    grid-template-columns: minmax(0, 1fr);
    gap: 0.85rem;
    padding: 0.9rem;
    border: 1px solid rgba(29, 29, 31, 0.1);
    border-radius: var(--radius-lg);
    background: rgba(255, 255, 255, 0.92);
    box-shadow: 0 18px 48px rgba(15, 23, 42, 0.16);
    backdrop-filter: blur(18px);
}

.pdfmerge-action-bar strong,
.pdfmerge-action-bar span {
    display: block;
}

.pdfmerge-progress {
    height: 0.42rem;
    margin-top: 0.55rem;
    overflow: hidden;
    border-radius: 999px;
    background: rgba(29, 29, 31, 0.08);
}

.pdfmerge-progress span {
    display: block;
    width: 0;
    height: 100%;
    border-radius: inherit;
    background: linear-gradient(90deg, var(--accent), #34c759);
    transition: width 0.2s ease;
}

.pdfmerge-action-bar .button {
    width: 100%;
}

.pdfmerge-action-bar .button:disabled {
    cursor: not-allowed;
    opacity: 0.52;
    transform: none;
}

@keyframes pdfmerge-shimmer {
    from { background-position: 180% 0; }
    to { background-position: -40% 0; }
}

@media (min-width: 740px) {
    .pdfmerge-header {
        grid-template-columns: minmax(0, 1fr) minmax(15rem, 0.42fr);
        align-items: center;
        padding: 1.2rem;
    }

    .pdfmerge-result-actions {
        width: auto;
        grid-template-columns: repeat(2, auto);
    }

    .pdfmerge-action-bar {
        grid-template-columns: minmax(0, 1fr) auto;
        align-items: center;
    }
}

@media (min-width: 1000px) {
    .pdfmerge-layout {
        grid-template-columns: minmax(0, 1fr) 320px;
        align-items: start;
    }

    .pdfmerge-sidebar {
        position: sticky;
        top: 6.8rem;
    }
}

@media (max-width: 560px) {
    .pdfmerge-page-grid {
        grid-template-columns: repeat(2, minmax(0, 1fr));
    }

    .pdfmerge-section-head,
    .pdfmerge-result {
        flex-direction: column;
        align-items: stretch;
    }

    .pdfmerge-toolbar {
        justify-content: flex-start;
    }
}

@media (prefers-color-scheme: dark) {
    .pdfmerge-header,
    .pdfmerge-dropzone,
    .pdfmerge-files,
    .pdfmerge-pages,
    .pdfmerge-result,
    .pdfmerge-settings-card,
    .pdfmerge-file-card,
    .pdfmerge-page-card,
    .pdfmerge-toggle,
    .pdfmerge-check,
    .pdfmerge-setting-row,
    .pdfmerge-action-bar {
        background: rgba(30, 32, 36, 0.82);
        border-color: rgba(255, 255, 255, 0.1);
    }
}

@media (prefers-reduced-motion: reduce) {
    .pdfmerge-tool *,
    .pdfmerge-tool *::before,
    .pdfmerge-tool *::after {
        animation-duration: 0.001ms !important;
        transition-duration: 0.001ms !important;
        scroll-behavior: auto !important;
    }
}