:root {
    --pdf-merge-text: var(--foreground, #0f172a);
    --pdf-merge-muted: var(--muted-foreground, #475569);
    --pdf-merge-surface: var(--card, #ffffff);
    --pdf-merge-border: var(--border, rgba(15, 23, 42, 0.12));
    --pdf-merge-card-bg: var(--card, #ffffff);
    --pdf-merge-card-border: var(--border, rgba(15, 23, 42, 0.08));
    --pdf-merge-dropzone-bg: rgba(248, 250, 252, 0.92);
    --pdf-merge-dropzone-border: rgba(15, 23, 42, 0.1);
    --pdf-merge-file-list-bg: rgba(248, 250, 252, 0.92);
    --pdf-merge-overlay-bg: rgba(15, 23, 42, 0.35);
    --pdf-merge-secondary-bg: rgba(15, 23, 42, 0.04);
    --pdf-merge-secondary-border: rgba(15, 23, 42, 0.08);
    --pdf-merge-primary: var(--primary, #6d28d9);
    --pdf-merge-primary-hover: var(--pdf-merge-primary);
    --pdf-merge-primary-foreground: var(--primary-foreground, #f8fafc);
    --pdf-merge-destructive: var(--destructive, #dc2626);
    --pdf-merge-destructive-hover: var(--pdf-merge-destructive);
    --pdf-merge-destructive-foreground: var(--destructive-foreground, #fef2f2);
}

html.dark {
    --pdf-merge-text: var(--foreground, #e2e8f0);
    --pdf-merge-muted: var(--muted-foreground, #94a3b8);
    --pdf-merge-surface: var(--card, rgba(15, 23, 42, 0.94));
    --pdf-merge-border: var(--border, rgba(148, 163, 184, 0.35));
    --pdf-merge-card-bg: rgba(15, 23, 42, 0.85);
    --pdf-merge-card-border: rgba(148, 163, 184, 0.35);
    --pdf-merge-dropzone-bg: rgba(2, 6, 23, 0.65);
    --pdf-merge-dropzone-border: rgba(148, 163, 184, 0.35);
    --pdf-merge-file-list-bg: rgba(8, 11, 25, 0.55);
    --pdf-merge-overlay-bg: rgba(2, 6, 23, 0.55);
    --pdf-merge-secondary-bg: rgba(148, 163, 184, 0.08);
    --pdf-merge-secondary-border: rgba(148, 163, 184, 0.3);
}

@supports (color: color-mix(in srgb, black 50%, white 50%)) {
    :root {
        --pdf-merge-primary-hover: color-mix(in srgb, var(--pdf-merge-primary) 90%, #000000);
        --pdf-merge-destructive-hover: color-mix(in srgb, var(--pdf-merge-destructive) 90%, #000000);
    }
}
* {
    box-sizing: border-box;
}
body.pdf-merge-no-scroll {
    overflow: hidden;
}
.demo-layout {
    max-width: 480px;
    text-align: center;
}
.demo-layout h1 {
    margin-bottom: 0.5rem;
    font-size: 2rem;
}
.demo-layout p {
    margin-bottom: 1.5rem;
    color: var(--pdf-merge-muted);
}
.demo-open-btn {
    border: none;
    border-radius: 999px;
    padding: 0.85rem 2rem;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    background: var(--pdf-merge-primary);
    color: #041220;
    box-shadow: 0 12px 32px rgba(56, 189, 248, 0.25);
    transition: transform 0.2s ease, box-shadow 0.2s ease;
}
.demo-open-btn:hover {
    transform: translateY(-1px) scale(1.01);
    box-shadow: 0 18px 36px rgba(56, 189, 248, 0.35);
}
.pdf-merge-overlay {
    position: fixed;
    inset: 0;
    background: var(--pdf-merge-overlay-bg);
    backdrop-filter: blur(14px);
    -webkit-backdrop-filter: blur(14px);
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 1.5rem;
    z-index: 9999;
    transition: opacity 0.2s ease;
    font-family: 'Inter', 'Segoe UI', system-ui, -apple-system, sans-serif;
    color: var(--pdf-merge-text);
    color-scheme: light dark;
}
.pdf-merge-overlay[aria-hidden="true"] {
    opacity: 0;
    pointer-events: none;
}
.pdf-merge-modal {
    width: min(640px, 100%);
    background: var(--pdf-merge-surface);
    border-radius: 1.25rem;
    border: 1px solid var(--pdf-merge-border);
    padding: 2rem;
    box-shadow: 0 25px 60px rgba(0, 0, 0, 0.25);
    outline: none;
    color: var(--pdf-merge-text);
}
.pdf-merge-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 1rem;
}
.pdf-merge-header h2 {
    margin: 0;
    font-size: 1.5rem;
}
.pdf-merge-close {
    background: transparent;
    border: 1px solid var(--pdf-merge-destructive);
    color: var(--pdf-merge-destructive);
    border-radius: 10px;
    padding: 0.35rem 1rem;
    cursor: pointer;
    font-size: 0.9rem;
}
.pdf-merge-close:hover {
    background: color-mix(in srgb, var(--pdf-merge-destructive) 12%, transparent);
    border-color: var(--pdf-merge-destructive-hover);
    color: var(--pdf-merge-destructive);
}
.pdf-merge-subtitle {
    margin: 0.75rem 0 1.5rem;
    color: var(--pdf-merge-muted);
    font-size: 0.95rem;
}
.pdf-merge-subtitle strong {
    font-weight: 600;
    color: var(--pdf-merge-text);
}
.pdf-merge-dropzone {
    border: 1.5px dashed var(--pdf-merge-dropzone-border);
    border-radius: 1rem;
    padding: 1.75rem;
    text-align: center;
    background: var(--pdf-merge-dropzone-bg);
    transition: border-color 0.2s ease, background 0.2s ease;
    cursor: pointer;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 0.35rem;
}
.pdf-merge-dropzone-title {
    margin: 0;
    font-weight: 600;
}
.pdf-merge-dropzone-hint {
    margin: 0.35rem 0 1rem;
    color: var(--pdf-merge-muted);
    font-size: 0.9rem;
}
.pdf-merge-dropzone-active {
    border-color: var(--pdf-merge-primary);
    background: color-mix(in srgb, var(--pdf-merge-primary) 8%, var(--pdf-merge-dropzone-bg));
}
.pdf-merge-upload-btn {
    width: auto;
}
.pdf-merge-list-label {
    margin: 1.5rem 0 0.35rem;
    font-size: 0.9rem;
    color: var(--pdf-merge-muted);
    text-transform: uppercase;
    letter-spacing: 0.06em;
}
.pdf-merge-file-list {
    border: 1px solid var(--pdf-merge-card-border);
    border-radius: 1rem;
    padding: 1rem;
    max-height: 220px;
    overflow-y: auto;
    display: flex;
    flex-direction: column;
    gap: 0.75rem;
    background: var(--pdf-merge-file-list-bg);
}
.pdf-merge-empty {
    margin: 0.5rem 0 0;
    color: var(--pdf-merge-muted);
    text-align: center;
}
.pdf-merge-card {
    display: flex;
    align-items: center;
    gap: 0.85rem;
    border: 1px solid var(--pdf-merge-card-border);
    border-radius: 0.9rem;
    padding: 0.75rem 1rem;
    background: var(--pdf-merge-card-bg);
}
.pdf-merge-card-index {
    width: 2rem;
    height: 2rem;
    border-radius: 999px;
    border: 2px solid var(--pdf-merge-primary);
    color: var(--pdf-merge-primary);
    background: transparent;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    font-weight: 600;
    font-size: 0.95rem;
}
.pdf-merge-card-name {
    flex: 1;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
}
.pdf-merge-card-remove {
    background: transparent;
    border: 1px solid var(--pdf-merge-destructive);
    color: var(--pdf-merge-destructive);
    border-radius: 10px;
    padding: 0.35rem 0.9rem;
    font-size: 0.85rem;
    cursor: pointer;
}
.pdf-merge-card-remove:hover {
    background: color-mix(in srgb, var(--pdf-merge-destructive) 12%, transparent);
    border-color: var(--pdf-merge-destructive);
}
.pdf-merge-card-dragging {
    opacity: 0.65;
}
.pdf-merge-buttons {
    display: flex;
    flex-wrap: wrap;
    gap: 0.75rem;
    margin-top: 1.5rem;
}
.pdf-merge-btn {
    flex: 1;
    border-radius: 10px;
    padding: 0.85rem 1.25rem;
    font-weight: 600;
    font-size: 1rem;
    cursor: pointer;
    border: none;
    transition: background 0.2s ease, color 0.2s ease, transform 0.2s ease;
}
.pdf-merge-btn-primary {
    background: var(--pdf-merge-primary);
    color: var(--pdf-merge-primary-foreground);
    box-shadow: 0 12px 24px rgba(0, 0, 0, 0.15);
    box-shadow: 0 12px 24px color-mix(in srgb, var(--pdf-merge-primary) 35%, transparent);
}
.pdf-merge-btn-primary:hover {
    transform: translateY(-1px);
    background: var(--pdf-merge-primary-hover);
}
.pdf-merge-btn-secondary {
    background: var(--pdf-merge-secondary-bg);
    border: 1px solid var(--pdf-merge-secondary-border);
    color: var(--pdf-merge-text);
}
.pdf-merge-btn-secondary:hover {
    border-color: var(--pdf-merge-primary);
    color: var(--pdf-merge-primary);
}
.pdf-merge-btn-destructive {
    background: transparent;
    border: 1px solid var(--pdf-merge-destructive);
    color: var(--pdf-merge-destructive);
}
.pdf-merge-btn-destructive:hover {
    background: color-mix(in srgb, var(--pdf-merge-destructive) 12%, transparent);
    border-color: var(--pdf-merge-destructive-hover);
    color: var(--pdf-merge-destructive);
}
.pdf-merge-btn:disabled {
    cursor: not-allowed;
    opacity: 0.55;
    transform: none;
    box-shadow: none;
}
@media (max-width: 640px) {
    .pdf-merge-modal {
        padding: 1.5rem;
    }
    .pdf-merge-buttons {
        flex-direction: column;
    }
    .pdf-merge-btn {
        width: 100%;
    }
}