/* ── Query String Builder Tool ──────────────────────────────────── */
.qsb-section {
    --tool-accent: #6366F1;
    --tool-accent-rgb: 99, 102, 241;
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
}

/* Field group */
.qsb-field-group {
    display: flex;
    flex-direction: column;
    gap: 0.6rem;
}

.qsb-label {
    font-size: 0.8125rem;
    font-weight: 600;
    color: var(--text-light, #64748B);
    text-transform: uppercase;
    letter-spacing: 0.06em;
}

.qsb-label-opt {
    font-size: 0.8125rem;
    font-weight: 400;
    text-transform: none;
    letter-spacing: 0;
    opacity: 0.8;
}

/* Base URL row */
.qsb-base-row {
    display: flex;
    gap: 0.625rem;
    flex-wrap: wrap;
}

/* Generic input */
.qsb-input {
    flex: 1 1 260px;
    padding: 0.625rem 0.875rem;
    background: var(--input-bg, #fff);
    border: 1px solid var(--border-color, #e2e8f0);
    border-radius: 8px;
    color: var(--text-primary, #0F172A);
    font-size: 0.9375rem;
    transition: border-color 0.2s, box-shadow 0.2s;
    box-sizing: border-box;
}

.qsb-input::placeholder {
    color: var(--text-light, #64748B);
    opacity: 0.7;
}

.qsb-input:focus {
    outline: none;
    border-color: var(--tool-accent);
    box-shadow: 0 0 0 3px rgba(99, 102, 241, 0.12);
}

/* Fragment row */
.qsb-fragment-row {
    display: flex;
    align-items: stretch;
    background: var(--input-bg, #fff);
    border: 1px solid var(--border-color, #e2e8f0);
    border-radius: 8px;
    overflow: hidden;
    transition: border-color 0.2s, box-shadow 0.2s;
    max-width: 480px;
}

.qsb-fragment-row:focus-within {
    border-color: var(--tool-accent);
    box-shadow: 0 0 0 3px rgba(99, 102, 241, 0.12);
}

.qsb-fragment-hash {
    padding: 0.625rem 0.8rem;
    font-size: 1rem;
    font-weight: 700;
    color: var(--tool-accent);
    background: var(--bg-muted, #f8fafc);
    border-right: 1px solid var(--border-color, #e2e8f0);
    user-select: none;
    display: flex;
    align-items: center;
    flex-shrink: 0;
}

.qsb-input.qsb-fragment-input {
    flex: 1 1 auto;
    min-width: 0;
    border: none;
    border-radius: 0;
    box-shadow: none;
}

.qsb-input.qsb-fragment-input:focus {
    border: none;
    box-shadow: none;
}

/* Buttons */
.qsb-btn {
    display: inline-flex;
    align-items: center;
    gap: 0.35rem;
    padding: 0.6rem 1rem;
    border-radius: 8px;
    font-size: 0.9375rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.2s;
    border: 1px solid transparent;
    white-space: nowrap;
}

.qsb-btn:disabled {
    opacity: 0.45;
    cursor: not-allowed;
}

.qsb-btn-primary {
    background: var(--tool-accent);
    color: #fff;
}

.qsb-btn-primary:hover:not(:disabled) {
    filter: brightness(1.1);
}

.qsb-btn-secondary {
    background: transparent;
    border-color: var(--tool-accent);
    color: var(--tool-accent);
}

.qsb-btn-secondary:hover:not(:disabled) {
    background: rgba(99, 102, 241, 0.08);
}

.qsb-btn-ghost {
    background: transparent;
    border-color: var(--border-color, #e2e8f0);
    color: var(--text-light, #64748B);
}

.qsb-btn-ghost:hover:not(:disabled) {
    border-color: var(--tool-accent);
    color: var(--tool-accent);
}

/* Params header */
.qsb-params-header {
    display: flex;
    align-items: center;
    flex-wrap: wrap;
    gap: 0.5rem;
}

#qsb-add-btn {
    margin-left: auto;
}

/* Active param count badge */
.qsb-param-count {
    font-size: 0.8125rem;
    font-weight: 600;
    color: var(--tool-accent);
    background: rgba(99, 102, 241, 0.09);
    padding: 0.2rem 0.6rem;
    border-radius: 20px;
    white-space: nowrap;
}

/* Parameter rows container */
.qsb-rows {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
    min-height: 2.75rem;
}

/* Row entry animation */
@keyframes qsbRowIn {
    from {
        opacity: 0;
        transform: translateY(-6px);
    }

    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* Single row */
.qsb-row {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    animation: qsbRowIn 0.18s ease;
    /* removal transition */
    transition: opacity 0.15s ease, transform 0.15s ease;
    overflow: hidden;
}

/* Row being removed */
.qsb-row--removing {
    opacity: 0 !important;
    transform: translateY(-4px);
}

/* Per-row enable/disable checkbox */
.qsb-check-wrap {
    display: flex;
    align-items: center;
    cursor: pointer;
    flex-shrink: 0;
    padding: 2px;
}

.qsb-check-wrap input[type="checkbox"] {
    display: none;
}

.qsb-check-box {
    width: 16px;
    height: 16px;
    border: 1.5px solid var(--border-color, #e2e8f0);
    border-radius: 4px;
    background: var(--input-bg, #fff);
    transition: background 0.15s, border-color 0.15s;
    position: relative;
    flex-shrink: 0;
}

.qsb-check-wrap:hover .qsb-check-box {
    border-color: var(--tool-accent);
}

.qsb-check-wrap input:checked+.qsb-check-box {
    background: var(--tool-accent);
    border-color: var(--tool-accent);
}

.qsb-check-box::after {
    content: '';
    position: absolute;
    display: none;
    left: 3px;
    top: 0px;
    width: 5px;
    height: 9px;
    border: 2px solid #fff;
    border-top: none;
    border-left: none;
    transform: rotate(43deg);
}

.qsb-check-wrap input:checked+.qsb-check-box::after {
    display: block;
}

/* Row number */
.qsb-row-num {
    font-size: 0.875rem;
    font-weight: 700;
    color: var(--tool-accent);
    min-width: 1.4rem;
    text-align: right;
    flex-shrink: 0;
    transition: opacity 0.2s;
}

/* Row inputs */
.qsb-row .qsb-input {
    flex: 1 1 120px;
    min-width: 70px;
}

.qsb-row-sep {
    color: var(--text-light, #64748B);
    font-size: 0.9375rem;
    font-weight: 600;
    flex-shrink: 0;
}

/* Disabled row */
.qsb-row--disabled .qsb-row-num {
    opacity: 0.35;
}

.qsb-row--disabled .qsb-key-input,
.qsb-row--disabled .qsb-val-input {
    opacity: 0.4;
    text-decoration: line-through;
    text-decoration-color: var(--text-light, #64748B);
}

/* Remove button */
.qsb-remove-btn {
    background: transparent;
    border: 1px solid var(--border-color, #e2e8f0);
    border-radius: 6px;
    padding: 0.35rem 0.55rem;
    color: var(--text-light, #64748B);
    cursor: pointer;
    font-size: 0.9375rem;
    display: flex;
    align-items: center;
    transition: all 0.2s;
    flex-shrink: 0;
}

.qsb-remove-btn:hover {
    border-color: #EF4444;
    color: #EF4444;
}

/* Empty hint */
.qsb-empty-hint {
    font-size: 0.875rem;
    color: var(--text-light, #64748B);
    margin: 0;
    padding: 0.5rem 0;
}

/* Preview box */
.qsb-preview-box {
    background: var(--bg-muted, #f8fafc);
    border: 1px solid var(--border-color, #e2e8f0);
    border-radius: 8px;
    padding: 1rem 1.1rem;
    word-break: break-all;
    min-height: 3.25rem;
    display: flex;
    align-items: flex-start;
}

.qsb-preview-code {
    font-family: 'JetBrains Mono', 'Fira Code', 'Cascadia Code', monospace;
    font-size: 0.9375rem;
    white-space: pre-wrap;
    line-height: 1.6;
}

.qsb-preview-code .qsb-p-base {
    color: var(--text-primary, #0F172A);
}

.qsb-preview-code .qsb-p-sep,
.qsb-preview-code .qsb-p-eq,
.qsb-preview-code .qsb-p-amp {
    color: var(--text-light, #64748B);
}

.qsb-preview-code .qsb-p-key {
    color: #6366F1;
}

.qsb-preview-code .qsb-p-val {
    color: #0369a1;
}

.qsb-preview-code .qsb-p-frag-sep,
.qsb-preview-code .qsb-p-frag {
    color: #0d9488;
}

/* Actions row */
.qsb-actions {
    display: flex;
    align-items: center;
    gap: 0.625rem;
    flex-wrap: wrap;
    margin-top: 0.25rem;
}

/* Encoding select */
.qsb-encode-wrap {
    display: flex;
    align-items: center;
    gap: 0.45rem;
    margin-left: auto;
}

.qsb-encode-icon {
    color: var(--text-light, #64748B);
    font-size: 0.9375rem;
}

.qsb-select {
    background: var(--input-bg, #fff);
    border: 1px solid var(--border-color, #e2e8f0);
    border-radius: 8px;
    color: var(--text-primary, #0F172A);
    font-size: 0.875rem;
    padding: 0.5rem 0.75rem;
    cursor: pointer;
    transition: border-color 0.2s, box-shadow 0.2s;
    font-family: inherit;
}

.qsb-select:focus {
    outline: none;
    border-color: var(--tool-accent);
    box-shadow: 0 0 0 3px rgba(99, 102, 241, 0.12);
}

/* Responsive */
@media (max-width: 640px) {
    .qsb-base-row {
        flex-direction: column;
    }

    .qsb-fragment-row {
        max-width: 100%;
    }

    .qsb-encode-wrap {
        margin-left: 0;
        width: 100%;
    }

    .qsb-select {
        flex: 1;
    }
}

@media (max-width: 480px) {
    .qsb-row .qsb-input {
        flex: 1 1 70px;
        min-width: 60px;
    }
}

.qsb-section>.container {
    width: 100%;
    box-sizing: border-box;
}