/* ─── Formula Sheet pages ─── */

.formulas-page {
    max-width: 960px;
    margin: 0 auto;
    padding: 5.5rem 1.5rem 3rem;
}

.formulas-page-intro {
    margin-bottom: 2rem;
}

.formulas-page-intro h1 {
    font-size: 2rem;
    font-weight: 700;
    color: var(--color-text, #1e293b);
    margin-bottom: 0.5rem;
    line-height: 1.2;
}

.formulas-page-intro p {
    color: var(--color-text-light, #64748b);
    font-size: 1.05rem;
    line-height: 1.6;
    max-width: 640px;
}

/* ─── Search + sort controls ─── */

.formulas-controls {
    display: flex;
    gap: 0.75rem;
    align-items: center;
    margin-bottom: 1.5rem;
    flex-wrap: wrap;
}

.formulas-search {
    flex: 1;
    min-width: 220px;
    padding: 0.6rem 0.85rem;
    font-size: 0.95rem;
    font-family: inherit;
    border: 1px solid var(--color-border, #e2e8f0);
    border-radius: 6px;
    background: white;
    color: var(--color-text, #1e293b);
    transition: border-color 0.15s;
}

.formulas-search:focus {
    outline: none;
    border-color: var(--color-primary, #2563eb);
    box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.1);
}

.formulas-sort {
    padding: 0.6rem 0.75rem;
    font-size: 0.9rem;
    font-family: inherit;
    border: 1px solid var(--color-border, #e2e8f0);
    border-radius: 6px;
    background: white;
    color: var(--color-text, #1e293b);
}

.formulas-count {
    width: 100%;
    margin-top: 0.25rem;
    font-size: 0.825rem;
    color: var(--color-text-muted, #94a3b8);
}

/* ─── Category section ─── */

.formula-category {
    margin: 2rem 0 0.5rem;
}

.formula-category-heading {
    font-size: 0.7rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.06em;
    color: var(--color-text-muted, #94a3b8);
    margin-bottom: 0.85rem;
    padding-bottom: 0.5rem;
    border-bottom: 1px solid var(--color-border-light, #f1f5f9);
}

/* ─── Card ─── */

.formula-card {
    background: white;
    border: 1px solid var(--color-border, #e2e8f0);
    border-radius: 10px;
    padding: 1.5rem 1.5rem 1.25rem;
    margin-bottom: 1.25rem;
    box-shadow: 0 1px 2px rgba(15, 23, 42, 0.04);
    scroll-margin-top: 5rem;
}

.formula-card-header {
    display: flex;
    align-items: flex-start;
    gap: 1rem;
    margin-bottom: 1.25rem;
    padding-bottom: 1rem;
    border-bottom: 1px solid var(--color-border-light, #f1f5f9);
}

.formula-title-wrap {
    flex: 1;
    min-width: 0;
}

.formula-title {
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--color-text, #1e293b);
    margin: 0 0 0.4rem;
    line-height: 1.3;
}

.formula-title a {
    color: inherit;
    text-decoration: none;
}

.formula-title a:hover {
    color: var(--color-primary, #2563eb);
}

.formula-display {
    font-family: ui-monospace, 'SF Mono', Menlo, Consolas, monospace;
    font-size: 0.95rem;
    color: var(--color-text-light, #64748b);
    background: var(--color-bg-alt, #f8fafc);
    padding: 0.45rem 0.7rem;
    border-radius: 5px;
    display: inline-block;
    word-break: break-word;
}

.formula-actions {
    display: flex;
    gap: 0.4rem;
    flex-shrink: 0;
}

.formula-action-btn {
    font-family: inherit;
    font-size: 0.78rem;
    font-weight: 500;
    color: var(--color-text-light, #64748b);
    background: white;
    border: 1px solid var(--color-border, #e2e8f0);
    border-radius: 5px;
    padding: 0.35rem 0.7rem;
    cursor: pointer;
    transition: all 0.15s;
}

.formula-action-btn:hover {
    color: var(--color-primary, #2563eb);
    border-color: var(--color-primary, #2563eb);
}

.formula-action-btn.is-copied {
    color: var(--color-success, #10b981);
    border-color: var(--color-success, #10b981);
    background: rgba(16, 185, 129, 0.06);
}

/* ─── Card body ─── */

.formula-card-body {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 1.5rem;
}

@media (max-width: 720px) {
    .formula-card-body {
        grid-template-columns: 1fr;
    }
}

.formula-explanation p {
    color: var(--color-text-light, #64748b);
    font-size: 0.95rem;
    line-height: 1.65;
    margin: 0 0 0.75rem;
}

.formula-explanation-short {
    color: var(--color-text, #1e293b) !important;
    font-weight: 500;
}

.formula-excel-link {
    display: inline-block;
    margin-top: 0.5rem;
    font-size: 0.85rem;
    color: var(--color-primary, #2563eb);
    text-decoration: none;
    border-bottom: 1px solid currentColor;
}

.formula-excel-link::before {
    content: '↓ ';
    margin-right: 0.15rem;
}

.formula-excel-link:hover {
    color: var(--color-primary-dark, #1d4ed8);
}

/* ─── Calculator ─── */

.formula-section-heading {
    font-size: 0.75rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    color: var(--color-text-muted, #94a3b8);
    margin: 0 0 0.6rem;
}

.formula-section-heading + .formula-section-heading,
.formula-inputs + .formula-section-heading,
.formula-intermediates + .formula-section-heading {
    margin-top: 1rem;
}

.formula-inputs {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 0.75rem;
}

@media (max-width: 480px) {
    .formula-inputs {
        grid-template-columns: 1fr;
    }
}

.formula-input-field label {
    display: block;
    font-size: 0.8rem;
    font-weight: 500;
    color: var(--color-text, #1e293b);
    margin-bottom: 0.25rem;
}

.formula-input-field input {
    width: 100%;
    padding: 0.5rem 0.65rem;
    font-size: 0.95rem;
    font-family: inherit;
    border: 1px solid var(--color-border, #e2e8f0);
    border-radius: 5px;
    background: white;
    color: var(--color-text, #1e293b);
    box-sizing: border-box;
    transition: border-color 0.15s;
}

.formula-input-field input:focus {
    outline: none;
    border-color: var(--color-primary, #2563eb);
    box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.1);
}

.formula-input-field input::placeholder {
    color: var(--color-text-muted, #94a3b8);
}

.formula-intermediate-list {
    list-style: none;
    padding: 0;
    margin: 0;
    background: var(--color-bg-alt, #f8fafc);
    border: 1px solid var(--color-border-light, #f1f5f9);
    border-radius: 6px;
}

.formula-intermediate-list li {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 0.5rem 0.75rem;
    border-bottom: 1px solid var(--color-border-light, #f1f5f9);
    font-size: 0.85rem;
}

.formula-intermediate-list li:last-child {
    border-bottom: none;
}

.formula-intermediate-label {
    color: var(--color-text-light, #64748b);
    font-family: ui-monospace, 'SF Mono', Menlo, Consolas, monospace;
}

.formula-intermediate-value {
    color: var(--color-text, #1e293b);
    font-weight: 600;
}

.formula-result {
    background: linear-gradient(135deg, var(--color-bg-dark, #0f172a) 0%, #1e3a5f 100%);
    color: white;
    padding: 1rem 1.1rem;
    border-radius: 7px;
    display: flex;
    flex-direction: column;
    gap: 0.25rem;
}

.formula-result-label {
    font-size: 0.7rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.06em;
    color: rgba(255, 255, 255, 0.55);
}

.formula-result-value {
    font-size: 1.15rem;
    font-weight: 600;
    color: white;
    font-family: ui-monospace, 'SF Mono', Menlo, Consolas, monospace;
    word-break: break-word;
}

.formula-error {
    margin-top: 0.75rem;
    padding: 0.6rem 0.8rem;
    font-size: 0.85rem;
    color: #b91c1c;
    background: #fef2f2;
    border: 1px solid #fecaca;
    border-radius: 5px;
}

/* ─── Empty / loading ─── */

.formulas-empty {
    padding: 3rem 1rem;
    text-align: center;
    color: var(--color-text-muted, #94a3b8);
    font-size: 0.95rem;
}

/* ─── Embed mode ─── */

body.formula-embed {
    background: transparent;
    margin: 0;
    padding: 0;
}

body.formula-embed .formulas-page {
    padding: 0.5rem;
    max-width: none;
}

body.formula-embed .formula-card {
    margin: 0;
    box-shadow: none;
}