/* =========================================================================
   Ratio & Kitchen Formula Tools v1.0.0 — Front-end styles
   Front-end root: .rkf-root
   Admin wrapper:  .rkf-admin-wrap
   Family tokens:  --kk-* (KnifeKettle family DNA)
   PenNews sets html { font-size: 10px } — use absolute px for text.
   ========================================================================= */

/* -------- Family tokens (shared with the KnifeKettle family) -------- */
.rkf-root,
.rkf-admin-wrap {
    --kk-indigo:        #4f46e5;
    --kk-indigo-dark:   #4338ca;
    --kk-indigo-soft:   #eef2ff;
    --kk-text:          #111827;
    --kk-text-soft:     #4b5563;
    --kk-border:        #e5e7eb;
    --kk-bg:            #ffffff;
    --kk-bg-soft:       #f9fafb;
    --kk-error:         #b91c1c;
    --kk-error-soft:    #fef2f2;
    --kk-success:       #047857;
    --kk-radius:        12px;
    --kk-radius-sm:     8px;
    --kk-shadow:        0 1px 2px rgba(17,24,39,0.04), 0 1px 3px rgba(17,24,39,0.06);
    --kk-font:          -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
}

/* =========================================================================
   .rkf-root — front-end container
   ========================================================================= */
.rkf-root {
    box-sizing: border-box;
    font-family: var(--kk-font);
    color: var(--kk-text);
    background: var(--kk-bg);
    font-size: 16px;
    line-height: 1.5;
    max-width: 920px;
    margin: 1.25rem auto;
    padding: 0 1rem;
}
.rkf-root *,
.rkf-root *::before,
.rkf-root *::after { box-sizing: border-box; }

/* -------- Skip link -------- */
.rkf-root .rkf-skip {
    position: absolute;
    left: -9999px;
    top: 0;
    background: var(--kk-indigo);
    color: #fff;
    padding: 0.5rem 0.75rem;
    border-radius: var(--kk-radius-sm);
    font-size: 14px;
    font-weight: 600;
    z-index: 1000;
}
.rkf-root .rkf-skip:focus {
    left: 0.5rem;
    top: 0.5rem;
    outline: 2px solid var(--kk-indigo);
    outline-offset: 2px;
}

/* -------- Header -------- */
.rkf-root .rkf-header { padding: 0.5rem 0 1rem; }
.rkf-root .rkf-header h1 {
    font-size: 28px;
    font-weight: 700;
    color: var(--kk-indigo);
    letter-spacing: -0.01em;
    line-height: 1.2;
    margin: 0 0 0.25rem;
}
.rkf-root .rkf-header p {
    font-size: 16px;
    color: var(--kk-text-soft);
    margin: 0 0 0.25rem;
}
.rkf-root .rkf-header .rkf-tagline {
    font-size: 14px;
    color: var(--kk-text-soft);
    margin: 0;
}

/* -------- Tab strip -------- */
.rkf-root .rkf-tabs {
    display: flex;
    flex-wrap: nowrap;
    overflow-x: auto;
    scroll-snap-type: x proximity;
    gap: 0.5rem;
    padding: 0.5rem 0 0.75rem;
    margin: 0;
    border-bottom: 0;
}
.rkf-root .rkf-tab {
    flex: 0 0 auto;
    background: var(--kk-bg);
    border: 1px solid var(--kk-border);
    color: var(--kk-text);
    padding: 10px 14px;
    font-size: 15px;
    font-weight: 500;
    font-family: inherit;
    line-height: 1.2;
    min-height: 44px;
    white-space: nowrap;
    border-radius: var(--kk-radius-sm);
    cursor: pointer;
    transition: background 0.15s, color 0.15s, border-color 0.15s;
    scroll-snap-align: start;
}
.rkf-root .rkf-tab:hover {
    color: var(--kk-indigo);
    background: var(--kk-indigo-soft);
    border-color: var(--kk-indigo-soft);
}
.rkf-root .rkf-tab[aria-selected="true"] {
    background: var(--kk-indigo);
    border-color: var(--kk-indigo);
    color: #fff;
    font-weight: 600;
}
.rkf-root .rkf-tab:focus-visible {
    outline: 2px solid var(--kk-indigo);
    outline-offset: 2px;
}

/* -------- Panels -------- */
.rkf-root .rkf-panel {
    background: var(--kk-bg);
    border: 1px solid var(--kk-border);
    border-radius: var(--kk-radius);
    box-shadow: var(--kk-shadow);
    padding: 1rem 1.25rem 1.25rem;
    margin: 0 0 1rem;
}
.rkf-root .rkf-panel[hidden] { display: none; }
.rkf-root .rkf-panel-title {
    font-size: 20px;
    font-weight: 600;
    color: var(--kk-text);
    line-height: 1.3;
    margin: 0 0 0.25rem;
}
.rkf-root .rkf-panel-desc {
    font-size: 14px;
    color: var(--kk-text-soft);
    line-height: 1.5;
    margin: 0 0 1rem;
}

/* -------- Form -------- */
.rkf-root .rkf-form { margin: 0; }
.rkf-root .rkf-form-row {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 0.75rem 0.875rem;
    margin: 0 0 0.875rem;
}
.rkf-root .rkf-form-row .rkf-cell { display: flex; flex-direction: column; min-width: 0; }
.rkf-root .rkf-form-row .rkf-cell-wide { grid-column: 1 / -1; }
.rkf-root .rkf-cell label {
    font-size: 14px;
    font-weight: 500;
    color: var(--kk-text);
    margin-bottom: 0.25rem;
}
.rkf-root .rkf-cell input[type="number"],
.rkf-root .rkf-cell input[type="text"],
.rkf-root .rkf-cell select,
.rkf-root .rkf-cell textarea {
    font-size: 16px;       /* iOS zoom prevention */
    font-weight: normal;
    font-family: inherit;
    color: var(--kk-text);
    background: var(--kk-bg);
    border: 1px solid var(--kk-border);
    border-radius: var(--kk-radius-sm);
    padding: 10px 12px;
    line-height: 1.3;
    width: 100%;
    min-height: 44px;
}
.rkf-root .rkf-cell textarea { min-height: 80px; resize: vertical; }
.rkf-root .rkf-cell input:focus,
.rkf-root .rkf-cell select:focus,
.rkf-root .rkf-cell textarea:focus {
    outline: 2px solid var(--kk-indigo);
    outline-offset: 2px;
    border-color: var(--kk-indigo);
}
.rkf-root .rkf-cell input[aria-invalid="true"],
.rkf-root .rkf-cell select[aria-invalid="true"],
.rkf-root .rkf-cell textarea[aria-invalid="true"] {
    border-color: var(--kk-error);
    box-shadow: 0 0 0 2px var(--kk-error-soft);
}
.rkf-root .rkf-help {
    display: block;
    font-size: 13px;
    font-weight: normal;
    color: var(--kk-text-soft);
    line-height: 1.4;
    margin-top: 0.25rem;
}
.rkf-root .rkf-field-error {
    display: block;
    font-size: 13px;
    font-weight: 500;
    color: var(--kk-error);
    background: var(--kk-error-soft);
    border-radius: 6px;
    padding: 0.25rem 0.5rem;
    margin-top: 0.25rem;
    line-height: 1.4;
}
.rkf-root .rkf-field-error[hidden] { display: none; }

/* -------- Buttons -------- */
.rkf-root .rkf-btn-row {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
    margin: 0.5rem 0 0;
}
.rkf-root .rkf-btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    font-size: 16px;
    font-weight: 600;
    font-family: inherit;
    line-height: 1.2;
    padding: 10px 16px;
    min-height: 44px;
    min-width: 44px;
    border-radius: var(--kk-radius-sm);
    border: 1px solid var(--kk-indigo);
    background: var(--kk-indigo);
    color: #fff;
    cursor: pointer;
    transition: background 0.15s, border-color 0.15s, color 0.15s;
}
.rkf-root .rkf-btn:hover { background: var(--kk-indigo-dark); border-color: var(--kk-indigo-dark); }
.rkf-root .rkf-btn:focus-visible { outline: 2px solid var(--kk-indigo); outline-offset: 2px; }
.rkf-root .rkf-btn-secondary {
    background: transparent;
    color: var(--kk-indigo);
}
.rkf-root .rkf-btn-secondary:hover {
    background: var(--kk-indigo-soft);
    color: var(--kk-indigo-dark);
    border-color: var(--kk-indigo);
}
.rkf-root .rkf-btn-ghost {
    background: transparent;
    color: var(--kk-text);
    border: 1px solid var(--kk-border);
}
.rkf-root .rkf-btn-ghost:hover {
    background: var(--kk-bg-soft);
    border-color: var(--kk-text-soft);
}

/* -------- Result region -------- */
.rkf-root .rkf-result {
    margin-top: 1.25rem;
    border: 1px solid var(--kk-border);
    border-radius: var(--kk-radius);
    background: var(--kk-bg);
    box-shadow: var(--kk-shadow);
    overflow: hidden;
}
.rkf-root .rkf-result[hidden] { display: none; }
.rkf-root .rkf-result-title {
    background: var(--kk-indigo);
    color: #fff;
    padding: 0.875rem 1rem;
    font-size: 16px;
    font-weight: 600;
    line-height: 1.3;
}
.rkf-root .rkf-result-body {
    padding: 1rem;
    font-variant-numeric: tabular-nums;
}
.rkf-root .rkf-result-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 0.75rem;
}
.rkf-root .rkf-stat {
    background: var(--kk-bg-soft);
    border: 1px solid var(--kk-border);
    border-radius: var(--kk-radius-sm);
    padding: 0.75rem 0.875rem;
}
.rkf-root .rkf-stat-label {
    font-size: 13px;
    color: var(--kk-text-soft);
    font-weight: 500;
    line-height: 1.3;
    margin-bottom: 0.125rem;
}
.rkf-root .rkf-stat-value {
    font-size: 20px;
    font-weight: 700;
    color: var(--kk-text);
    line-height: 1.2;
    font-variant-numeric: tabular-nums;
}
.rkf-root .rkf-stat-pill {
    display: inline-block;
    margin-top: 0.25rem;
    font-size: 13px;
    font-weight: 600;
    color: var(--kk-indigo);
    background: var(--kk-indigo-soft);
    padding: 0.125rem 0.5rem;
    border-radius: 999px;
    line-height: 1.3;
}
.rkf-root .rkf-result-detail {
    list-style: disc;
    padding-left: 1.25rem;
    margin: 0.75rem 0 0;
    font-size: 14px;
    color: var(--kk-text);
    line-height: 1.5;
}
.rkf-root .rkf-result-detail li { margin: 0 0 0.125rem; }
.rkf-root .rkf-result-note {
    margin: 0.75rem 0 0;
    padding: 0.5rem 0.75rem;
    background: var(--kk-indigo-soft);
    border-left: 3px solid var(--kk-indigo);
    border-radius: 6px;
    font-size: 14px;
    color: var(--kk-text);
    line-height: 1.5;
}
.rkf-root .rkf-result-disclaimer {
    margin: 0.75rem 0 0;
    padding-top: 0.5rem;
    border-top: 1px solid var(--kk-border);
    font-size: 13px;
    font-style: italic;
    color: var(--kk-text-soft);
    line-height: 1.5;
}

/* -------- Footer -------- */
.rkf-root .rkf-footer {
    margin-top: 1.25rem;
    padding-top: 1rem;
    border-top: 1px solid var(--kk-border);
    font-size: 13px;
    color: var(--kk-text-soft);
    line-height: 1.5;
}
.rkf-root .rkf-footer p { margin: 0 0 0.25rem; }

/* =========================================================================
   .rkf-admin-wrap — admin help page
   ========================================================================= */
.rkf-admin-wrap {
    font-family: var(--kk-font);
    color: var(--kk-text);
}
.rkf-admin-wrap code {
    background: var(--kk-bg-soft);
    border: 1px solid var(--kk-border);
    border-radius: 6px;
    padding: 1px 6px;
    font-size: 14px;
}
.rkf-admin-wrap .button {
    background: var(--kk-indigo);
    color: #fff;
    border: 1px solid var(--kk-indigo);
    border-radius: var(--kk-radius-sm);
    padding: 4px 12px;
    font-size: 14px;
    font-weight: 600;
    cursor: pointer;
}
.rkf-admin-wrap .button:hover {
    background: var(--kk-indigo-dark);
    border-color: var(--kk-indigo-dark);
}
.rkf-admin-wrap ol li { margin: 0 0 0.5rem; line-height: 1.5; }

/* =========================================================================
   Mobile @media
   ========================================================================= */
@media (max-width: 720px) {
    .rkf-root .rkf-header h1 { font-size: 24px; }
    .rkf-root .rkf-tab { font-size: 14px; padding: 8px 12px; }
    .rkf-root .rkf-stat-value { font-size: 18px; }
    .rkf-root .rkf-result-grid { grid-template-columns: 1fr; }
}

/* =========================================================================
   Print @media
   ========================================================================= */
@media print {
    .rkf-root { background: #fff; max-width: none; padding: 0; margin: 0; }
    .rkf-root .rkf-header,
    .rkf-root .rkf-tabs,
    .rkf-root .rkf-form,
    .rkf-root .rkf-btn-row,
    .rkf-root .rkf-footer,
    .rkf-root .rkf-skip,
    .rkf-root .rkf-panel:not(.rkf-print-active) { display: none !important; }
    .rkf-root .rkf-panel { box-shadow: none; border: 0; padding: 0; page-break-after: always; }
    .rkf-root .rkf-result { box-shadow: none; border: 0; }
    .rkf-root .rkf-result-title { background: #fff; color: var(--kk-text); padding: 0; }
}