/* ============================================================
   Speed / Distance / Time Calculator — bkbg-spd-*
   ============================================================ */

.bkbg-spd-wrap {
    box-sizing: border-box;
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    padding: 32px 24px;
    border-radius: 14px;
    max-width: var(--spd-max-width, 680px);
    margin: 0 auto;
}

/* ---- Header ---- */
.bkbg-spd-title {
    font-family: var(--bkspd-tt-font-family, inherit);
    font-size: var(--bkspd-tt-font-size-d, 26px);
    font-weight: var(--bkspd-tt-font-weight, 700);
    font-style: var(--bkspd-tt-font-style, normal);
    text-decoration: var(--bkspd-tt-text-decoration, none);
    text-transform: var(--bkspd-tt-text-transform, none);
    line-height: var(--bkspd-tt-line-height-d, 1.25);
    letter-spacing: var(--bkspd-tt-letter-spacing-d, normal);
    word-spacing: var(--bkspd-tt-word-spacing-d, normal);
    color: var(--spd-title-color, #111827);
    margin: 0 0 5px;
}
.bkbg-spd-wrap h3.bkbg-spd-title {
    font-family: var(--bkspd-tt-font-family);
    font-size: var(--bkspd-tt-font-size-d, 26px);
    font-weight: var(--bkspd-tt-font-weight, 700);
    font-style: var(--bkspd-tt-font-style, normal);
    text-decoration: var(--bkspd-tt-text-decoration, none);
    text-transform: var(--bkspd-tt-text-transform, none);
    line-height: var(--bkspd-tt-line-height-d, 1.25);
    letter-spacing: var(--bkspd-tt-letter-spacing-d, normal);
    word-spacing: var(--bkspd-tt-word-spacing-d, normal);
}

.bkbg-spd-subtitle {
    font-family: var(--bkspd-st-font-family, inherit);
    font-size: var(--bkspd-st-font-size-d, 14px);
    font-weight: var(--bkspd-st-font-weight, normal);
    font-style: var(--bkspd-st-font-style, normal);
    text-decoration: var(--bkspd-st-text-decoration, none);
    text-transform: var(--bkspd-st-text-transform, none);
    line-height: var(--bkspd-st-line-height-d, 1.5);
    letter-spacing: var(--bkspd-st-letter-spacing-d, normal);
    word-spacing: var(--bkspd-st-word-spacing-d, normal);
    color: var(--spd-subtitle-color, #6b7280);
    margin: 0 0 24px;
}

/* ---- Solve-for tabs ---- */
.bkbg-spd-tab-label {
    font-size: 11px;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: .07em;
    color: var(--spd-label-color, #374151);
    margin-bottom: 8px;
}

.bkbg-spd-tabs {
    display: flex;
    gap: 8px;
    flex-wrap: wrap;
    margin-bottom: 22px;
}

.bkbg-spd-tab {
    padding: 7px 18px;
    border-radius: 9px;
    border: 2px solid #e5e7eb;
    background: transparent;
    color: var(--spd-label-color, #374151);
    font-weight: 500;
    font-size: 13px;
    cursor: pointer;
    transition: background .15s, border-color .15s, color .15s;
    line-height: 1.4;
}

.bkbg-spd-tab:hover {
    border-color: var(--spd-accent, #3b82f6);
    color: var(--spd-accent, #3b82f6);
}

.bkbg-spd-tab.active {
    background: var(--spd-accent, #3b82f6);
    border-color: var(--spd-accent, #3b82f6);
    color: #fff;
    font-weight: 700;
}

/* ---- Inputs grid ---- */
.bkbg-spd-inputs {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(190px, 1fr));
    gap: 12px;
    margin-bottom: 20px;
}

.bkbg-spd-field {
    border-radius: 12px;
    padding: 16px;
    border: 2px solid #e5e7eb;
    transition: border-color .15s, box-shadow .15s;
}

.bkbg-spd-field:focus-within {
    border-color: var(--spd-accent, #3b82f6);
    box-shadow: 0 0 0 3px rgba(59,130,246,.12);
}

.bkbg-spd-field.is-result {
    border-color: var(--spd-result-border, #3b82f6);
    background: var(--spd-result-bg, #dbeafe) !important;
}

.bkbg-spd-field-label {
    font-size: 11px;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: .07em;
    margin-bottom: 8px;
}

.bkbg-spd-input {
    width: 100%;
    box-sizing: border-box;
    border: 1.5px solid #e5e7eb;
    border-radius: 8px;
    padding: 9px 11px;
    font-size: 16px;
    font-weight: 600;
    color: var(--spd-label-color, #374151);
    background: var(--spd-input-bg, #f8fafc);
    margin-bottom: 8px;
    outline: none;
    transition: border-color .15s;
}

.bkbg-spd-input:focus {
    border-color: var(--spd-accent, #3b82f6);
}

.bkbg-spd-input:disabled {
    background: transparent;
    border-color: transparent;
    cursor: default;
    font-size: 28px;
    font-weight: 700;
    padding: 4px 0;
}

.bkbg-spd-unit-select {
    width: 100%;
    box-sizing: border-box;
    border: 1.5px solid #e5e7eb;
    border-radius: 7px;
    padding: 6px 8px;
    font-size: 13px;
    background: var(--spd-input-bg, #f8fafc);
    color: var(--spd-label-color, #374151);
    cursor: pointer;
    outline: none;
}

/* ---- Calculate button ---- */
.bkbg-spd-calc-btn {
    width: 100%;
    padding: 12px;
    border-radius: 10px;
    border: none;
    background: var(--spd-accent, #3b82f6);
    color: #fff;
    font-size: 15px;
    font-weight: 700;
    cursor: pointer;
    margin-bottom: 20px;
    transition: opacity .15s, transform .1s;
}

.bkbg-spd-calc-btn:hover  { opacity: .9; }
.bkbg-spd-calc-btn:active { transform: scale(.98); }

/* ---- Unit conversions table ---- */
.bkbg-spd-conversions {
    background: var(--spd-card-bg, #fff);
    border-radius: 12px;
    border: 1.5px solid #e5e7eb;
    padding: 14px 16px;
    margin-bottom: 16px;
}

.bkbg-spd-conv-heading {
    font-size: 12px;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: .07em;
    color: var(--spd-label-color, #374151);
    margin-bottom: 10px;
}

.bkbg-spd-conv-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(160px, 1fr));
    gap: 8px;
}

.bkbg-spd-conv-item {
    background: #f3f4f6;
    border-radius: 8px;
    padding: 8px 12px;
}

.bkbg-spd-conv-unit {
    font-size: 11px;
    color: var(--spd-label-color, #374151);
    margin-bottom: 2px;
    text-transform: uppercase;
    letter-spacing: .04em;
}

.bkbg-spd-conv-val {
    font-size: 15px;
    font-weight: 700;
    color: var(--spd-accent, #3b82f6);
}

/* ---- Formula ---- */
.bkbg-spd-formula {
    background: var(--spd-card-bg, #fff);
    border-radius: 10px;
    border: 1.5px solid #e5e7eb;
    padding: 12px 16px;
    display: flex;
    gap: 20px;
    flex-wrap: wrap;
    justify-content: center;
    align-items: center;
    margin-bottom: 16px;
}

.bkbg-spd-formula-item {
    font-size: 13px;
    font-weight: 600;
}

/* ---- Examples ---- */
.bkbg-spd-examples {
    background: var(--spd-card-bg, #fff);
    border-radius: 12px;
    border: 1.5px solid #e5e7eb;
    padding: 14px 16px;
}

.bkbg-spd-examples-heading {
    font-size: 12px;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: .07em;
    color: var(--spd-label-color, #374151);
    margin-bottom: 10px;
}

.bkbg-spd-example-row {
    display: flex;
    align-items: center;
    gap: 10px;
    padding: 6px 0;
    border-bottom: 1px solid #f3f4f6;
    font-size: 13px;
    color: var(--spd-label-color, #374151);
}

.bkbg-spd-example-row:last-child { border-bottom: none; }

.bkbg-spd-example-row strong {
    margin-left: auto;
    color: var(--spd-accent, #3b82f6);
}

/* ---- Responsive ---- */
@media (max-width: 1024px) {
    .bkbg-spd-title {
        font-size: var(--bkspd-tt-font-size-t, var(--bkspd-tt-font-size-d, 26px));
        line-height: var(--bkspd-tt-line-height-t, var(--bkspd-tt-line-height-d, 1.25));
        letter-spacing: var(--bkspd-tt-letter-spacing-t, var(--bkspd-tt-letter-spacing-d, normal));
        word-spacing: var(--bkspd-tt-word-spacing-t, var(--bkspd-tt-word-spacing-d, normal));
    }
    .bkbg-spd-wrap h3.bkbg-spd-title {
        font-size: var(--bkspd-tt-font-size-t, var(--bkspd-tt-font-size-d, 26px));
        line-height: var(--bkspd-tt-line-height-t, var(--bkspd-tt-line-height-d, 1.25));
        letter-spacing: var(--bkspd-tt-letter-spacing-t, var(--bkspd-tt-letter-spacing-d, normal));
        word-spacing: var(--bkspd-tt-word-spacing-t, var(--bkspd-tt-word-spacing-d, normal));
    }
    .bkbg-spd-subtitle {
        font-size: var(--bkspd-st-font-size-t, var(--bkspd-st-font-size-d, 14px));
        line-height: var(--bkspd-st-line-height-t, var(--bkspd-st-line-height-d, 1.5));
        letter-spacing: var(--bkspd-st-letter-spacing-t, var(--bkspd-st-letter-spacing-d, normal));
        word-spacing: var(--bkspd-st-word-spacing-t, var(--bkspd-st-word-spacing-d, normal));
    }
}
@media (max-width: 767px) {
    .bkbg-spd-title {
        font-size: var(--bkspd-tt-font-size-m, var(--bkspd-tt-font-size-t, var(--bkspd-tt-font-size-d, 26px)));
        line-height: var(--bkspd-tt-line-height-m, var(--bkspd-tt-line-height-t, var(--bkspd-tt-line-height-d, 1.25)));
        letter-spacing: var(--bkspd-tt-letter-spacing-m, var(--bkspd-tt-letter-spacing-t, var(--bkspd-tt-letter-spacing-d, normal)));
        word-spacing: var(--bkspd-tt-word-spacing-m, var(--bkspd-tt-word-spacing-t, var(--bkspd-tt-word-spacing-d, normal)));
    }
    .bkbg-spd-wrap h3.bkbg-spd-title {
        font-size: var(--bkspd-tt-font-size-m, var(--bkspd-tt-font-size-t, var(--bkspd-tt-font-size-d, 26px)));
        line-height: var(--bkspd-tt-line-height-m, var(--bkspd-tt-line-height-t, var(--bkspd-tt-line-height-d, 1.25)));
        letter-spacing: var(--bkspd-tt-letter-spacing-m, var(--bkspd-tt-letter-spacing-t, var(--bkspd-tt-letter-spacing-d, normal)));
        word-spacing: var(--bkspd-tt-word-spacing-m, var(--bkspd-tt-word-spacing-t, var(--bkspd-tt-word-spacing-d, normal)));
    }
    .bkbg-spd-subtitle {
        font-size: var(--bkspd-st-font-size-m, var(--bkspd-st-font-size-t, var(--bkspd-st-font-size-d, 14px)));
        line-height: var(--bkspd-st-line-height-m, var(--bkspd-st-line-height-t, var(--bkspd-st-line-height-d, 1.5)));
        letter-spacing: var(--bkspd-st-letter-spacing-m, var(--bkspd-st-letter-spacing-t, var(--bkspd-st-letter-spacing-d, normal)));
        word-spacing: var(--bkspd-st-word-spacing-m, var(--bkspd-st-word-spacing-t, var(--bkspd-st-word-spacing-d, normal)));
    }
}
@media (max-width: 520px) {
    .bkbg-spd-wrap   { padding: 20px 14px; }
    .bkbg-spd-inputs { grid-template-columns: 1fr; }
    .bkbg-spd-formula { flex-direction: column; align-items: flex-start; gap: 6px; }
    .bkbg-spd-conv-grid { grid-template-columns: repeat(2, 1fr); }
}