:root {
    --cb-font: "Montserrat", "Inter", "Segoe UI", system-ui, sans-serif;
    --cb-radius: 1rem;
    --cb-shadow: 0 4px 12px rgba(0, 0, 0, .06);
    --cb-bg: #2456a0;
    --cb-link: #2563eb;
    --cb-link-hov: #1d4ed8;
    --cb-divider: rgba(0, 0, 0, .25);
}

/* front */
.nscb-breadcrumb {
    font-family: var(--cb-font);
    background: var(--cb-bg);
    padding: .75rem 1.25rem;
    border-radius: var(--cb-radius);
    box-shadow: var(--cb-shadow);
    overflow-x: auto;
    color: #fff;
}

.nscb-breadcrumb ol {
    margin: 0;
    padding: 0;
    list-style: none;
    display: flex;
    flex-wrap: wrap;
    gap: .5rem;
    align-items: center
}

.nscb-breadcrumb li {
    display: flex;
    align-items: center;
    font-size: .9rem;
    white-space: nowrap
}

.nscb-breadcrumb li+li::before {
    content: "/";
    margin-right: .5rem;
    color: var(--cb-divider)
}

.nscb-breadcrumb a {
    color: var(--cb-link);
    text-decoration: none;
    transition: color .2s
}

.nscb-breadcrumb a:hover {
    color: var(--cb-link-hov)
}

/* builder */
#nscb-wrapper {
    display: flex;
    gap: 1.5rem;
    flex-wrap: wrap;
    font-family: var(--cb-font)
}

#nscb-left {
    flex: 1 1 300px;
    max-height: 450px;
    overflow: auto;
    padding-right: 1rem;
    border-right: 1px solid #e5e7eb
}

#nscb-left details {
    margin-bottom: .5rem
}

#nscb-left summary {
    font-weight: 600;
    cursor: pointer;
    margin-bottom: .25rem
}

.nscb-item {
    display: block;
    padding: .15rem 0;
    font-size: .9rem;
    white-space: nowrap
}

#nscb-right {
    flex: 1 1 240px
}

#nscb-selected {
    margin: 0;
    padding: 0;
    list-style: none;
    counter-reset: cb
}

.nscb-sel {
    background: #fff;
    border: 1px solid #d1d5db;
    padding: .5rem .75rem;
    border-radius: .5rem;
    margin: .25rem 0;
    display: flex;
    align-items: center;
    cursor: move;
    box-shadow: var(--cb-shadow);
    transition: background .2s
}

.nscb-sel:hover {
    background: #f9fafb;
    color: #374151;
}

.nscb-sel::before {
    counter-increment: cb;
    content: counter(cb)".";
    font-weight: 600;
    color: #4b5563;
    margin-right: .5rem
}

.nscb-grip {
    margin-right: .5rem;
    cursor: move;
    color: #9ca3af;
    user-select: none
}

.nscb-sel:hover .nscb-grip {
    color: #6b7280
}

.nscb-remove {
    margin-left: auto;
    font-weight: 700;
    color: #ef4444;
    cursor: pointer
}

.nscb-current {
    margin-top: .5rem;
    padding: .5rem .75rem;
    border: 1px dashed #9ca3af;
    border-radius: .5rem;
    text-align: center;
    font-size: .85rem;
    color: #6b7280
}

.nscb-placeholder {
    background: #e5e7eb;
    border: 2px dashed #d1d5db;
    height: 2.5rem;
    margin: .25rem 0;
    border-radius: .5rem
}

/* dark mode */
@media(prefers-color-scheme:dark) {
    :root {
        --cb-bg: #2456a0;
        --cb-link: #fff;
        --cb-link-hov: #93c5fd;
        --cb-divider: rgba(255, 255, 255, .35)
    }

    .nscb-breadcrumb {
        box-shadow: none
    }

    .nscb-sel {
        background: #1f2937;
        border-color: #374151;
        color: #f3f4f6
    }

    .nscb-placeholder {
        background: #374151;
        border-color: #4b5563
    }

    .nscb-grip {
        color: #6b7280
    }

    .nscb-sel:hover .nscb-grip {
        color: #9ca3af
    }
}