/* ============================================
   UNCERTAINTY / ERROR PROPAGATION CALCULATOR
   Tool-specific styles. Uses shared.css tokens.
   Accent: engineering (amber).
   ============================================ */

.calculator-layout {
    display: grid;
    grid-template-columns: minmax(0, 1fr) 320px;
    gap: 24px;
    align-items: start;
    position: relative;
    z-index: 1;
    margin-top: 24px;
}

.calculator-panel,
.sidebar .info-panel {
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: 14px;
    padding: 24px;
}

.panel-header h2 {
    font-size: 1.5rem;
    margin-bottom: 6px;
}
.panel-header p {
    color: var(--text-secondary);
    font-size: 0.95rem;
    margin-bottom: 20px;
}

/* --- generic inputs --- */
.main-input,
.main-select,
.formula-input {
    width: 100%;
    background: var(--bg-input);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    color: var(--text-primary);
    padding: 10px 12px;
    font-size: 0.95rem;
    font-family: 'JetBrains Mono', monospace;
    transition: border-color 0.15s ease, box-shadow 0.15s ease;
}
.main-select {
    font-family: 'Space Grotesk', sans-serif;
    cursor: pointer;
}
.main-input:focus,
.main-select:focus,
.formula-input:focus {
    outline: none;
    border-color: var(--accent-engineering);
    box-shadow: 0 0 0 3px var(--accent-engineering-dim);
}
.formula-input {
    font-size: 1.15rem;
    padding: 14px 16px;
    letter-spacing: 0.02em;
}

.field-block { margin-bottom: 20px; }
.field-block > label,
.section-label {
    display: block;
    font-size: 0.8rem;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    color: var(--text-muted);
    margin-bottom: 8px;
    font-weight: 600;
}

.formula-row {
    display: flex;
    gap: 12px;
    align-items: center;
    flex-wrap: wrap;
}
.formula-row .formula-input { flex: 1 1 320px; }
.example-select { flex: 0 1 260px; }

.error-text {
    color: var(--accent-error);
    font-size: 0.85rem;
    font-family: 'JetBrains Mono', monospace;
    margin-top: 8px;
    min-height: 1.1em;
}
.hint-text {
    color: var(--text-muted);
    font-size: 0.85rem;
    margin-top: 6px;
}

/* --- variables table --- */
.vars-head,
.var-row {
    display: grid;
    grid-template-columns: minmax(64px, 1fr) minmax(90px, 1.4fr) minmax(110px, 1.4fr) 130px;
    gap: 10px;
    align-items: center;
}
.vars-head {
    font-size: 0.72rem;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    color: var(--text-muted);
    padding: 0 2px 8px;
    font-weight: 600;
}
.var-row { margin-bottom: 10px; }
.var-name {
    font-weight: 700;
    color: var(--accent-engineering);
    font-size: 1rem;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
}
.var-unc-wrap {
    display: flex;
    align-items: center;
    gap: 6px;
}
.var-unc-wrap .pm { color: var(--text-muted); font-family: 'JetBrains Mono', monospace; }
.var-unc:disabled { opacity: 0.4; cursor: not-allowed; }

.vars-empty {
    color: var(--text-muted);
    font-size: 0.9rem;
    padding: 12px 0;
}

/* --- options row --- */
.options-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
    gap: 14px;
    margin-top: 8px;
}
.option-item label {
    display: block;
    font-size: 0.78rem;
    text-transform: uppercase;
    letter-spacing: 0.04em;
    color: var(--text-muted);
    margin-bottom: 6px;
    font-weight: 600;
}
.checkbox-line {
    display: flex;
    align-items: center;
    gap: 8px;
    height: 42px;
}
.checkbox-line input { width: 18px; height: 18px; accent-color: var(--accent-engineering); }
.checkbox-line span { font-size: 0.9rem; }

/* --- buttons --- */
.tool-btn {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    background: var(--bg-secondary);
    border: 1px solid var(--border-color);
    color: var(--text-primary);
    padding: 9px 16px;
    border-radius: 8px;
    font-size: 0.9rem;
    font-weight: 500;
    cursor: pointer;
    font-family: inherit;
    transition: background 0.15s ease, border-color 0.15s ease, transform 0.05s ease;
}
.tool-btn:hover { background: var(--bg-card-hover); border-color: var(--border-hover); }
.tool-btn:active { transform: translateY(1px); }
.tool-btn.primary {
    background: var(--accent-engineering);
    border-color: var(--accent-engineering);
    color: #1a1a1a;
    font-weight: 600;
}
.tool-btn.primary:hover { filter: brightness(1.08); }

/* --- result hero --- */
.result-hero {
    margin-top: 24px;
    background: linear-gradient(180deg, var(--accent-engineering-dim), transparent);
    border: 1px solid var(--border-color);
    border-radius: 14px;
    padding: 22px 24px;
}
.result-hero.empty { opacity: 0.55; }
.result-label {
    font-size: 0.78rem;
    text-transform: uppercase;
    letter-spacing: 0.06em;
    color: var(--text-muted);
    font-weight: 600;
}
.result-main {
    display: flex;
    align-items: baseline;
    gap: 10px;
    flex-wrap: wrap;
    margin: 6px 0 4px;
    font-family: 'JetBrains Mono', monospace;
}
#resultValue { font-size: 2.4rem; font-weight: 700; line-height: 1.1; }
#resultUnc { font-size: 1.5rem; color: var(--accent-engineering); font-weight: 600; }
.result-sub {
    display: flex;
    gap: 8px 20px;
    flex-wrap: wrap;
    color: var(--text-secondary);
    font-size: 0.9rem;
    margin-top: 4px;
}
#resultExpanded { font-family: 'JetBrains Mono', monospace; }
.dominant {
    margin-top: 12px;
    padding: 10px 12px;
    background: var(--bg-secondary);
    border-left: 3px solid var(--accent-engineering);
    border-radius: 6px;
    font-size: 0.9rem;
}
.result-actions {
    display: flex;
    align-items: center;
    gap: 12px;
    margin-top: 14px;
}
.copy-feedback { color: var(--accent-success); font-size: 0.85rem; }

/* --- steps (foldable) --- */
details.steps {
    margin-top: 18px;
    border: 1px solid var(--border-color);
    border-radius: 12px;
    background: var(--bg-secondary);
    overflow: hidden;
}
details.steps > summary {
    cursor: pointer;
    padding: 14px 18px;
    font-weight: 600;
    font-size: 0.95rem;
    list-style: none;
    display: flex;
    align-items: center;
    gap: 10px;
    user-select: none;
}
details.steps > summary::-webkit-details-marker { display: none; }
details.steps > summary::before {
    content: '▸';
    color: var(--accent-engineering);
    transition: transform 0.15s ease;
}
details.steps[open] > summary::before { transform: rotate(90deg); }
details.steps > summary:hover { background: var(--bg-card-hover); }

.steps-inner { padding: 4px 18px 20px; }
.steps-formula { color: var(--text-secondary); font-size: 0.9rem; margin-bottom: 6px; }
.steps-eq {
    font-size: 1.05rem;
    padding: 10px 14px;
    background: var(--bg-input);
    border-radius: 8px;
    display: inline-block;
    margin-bottom: 16px;
}
.steps-table-wrap { overflow-x: auto; }
.steps-table {
    width: 100%;
    border-collapse: collapse;
    font-size: 0.85rem;
    min-width: 560px;
}
.steps-table th {
    text-align: left;
    color: var(--text-muted);
    font-weight: 600;
    font-size: 0.72rem;
    text-transform: uppercase;
    letter-spacing: 0.04em;
    padding: 8px 10px;
    border-bottom: 1px solid var(--border-color);
}
.steps-table td {
    padding: 9px 10px;
    border-bottom: 1px solid var(--border-color);
    vertical-align: middle;
}
.steps-table td.num { text-align: right; white-space: nowrap; }
.steps-table td.deriv { color: var(--text-secondary); }
.bar-wrap {
    display: inline-block;
    width: 70px;
    height: 7px;
    background: var(--bg-input);
    border-radius: 4px;
    overflow: hidden;
    vertical-align: middle;
    margin-right: 8px;
}
.bar-wrap .bar {
    display: block;
    height: 100%;
    background: var(--accent-engineering);
    border-radius: 4px;
}
.steps-table .pct { font-family: 'JetBrains Mono', monospace; color: var(--text-secondary); }
.steps-sum {
    margin-top: 14px;
    font-size: 0.95rem;
    padding: 10px 14px;
    background: var(--bg-input);
    border-radius: 8px;
}
.steps-caveat, .mc-note {
    margin-top: 12px;
    color: var(--text-muted);
    font-size: 0.82rem;
    line-height: 1.5;
}
.mc-summary {
    margin-top: 18px;
    padding-top: 14px;
    border-top: 1px dashed var(--border-color);
}
.mc-summary h4 { font-size: 0.95rem; margin-bottom: 6px; }
.mc-summary p { color: var(--text-secondary); font-size: 0.85rem; }
.mc-summary ul { list-style: none; margin: 8px 0; }
.mc-summary li { font-size: 0.88rem; padding: 2px 0; }

.mono { font-family: 'JetBrains Mono', monospace; }

/* --- sidebar --- */
.sidebar { position: relative; z-index: 1; margin-top: 24px; display: flex; flex-direction: column; gap: 20px; }
.sidebar h3 { font-size: 1rem; margin-bottom: 10px; }
.sidebar h3:not(:first-child) { margin-top: 20px; }
.sidebar p, .sidebar li { color: var(--text-secondary); font-size: 0.88rem; line-height: 1.55; }
.sidebar ol, .sidebar ul { padding-left: 18px; }
.sidebar li { margin-bottom: 6px; }
.syntax-help code {
    font-family: 'JetBrains Mono', monospace;
    background: var(--bg-input);
    border: 1px solid var(--border-color);
    border-radius: 4px;
    padding: 1px 5px;
    font-size: 0.82rem;
    color: var(--text-primary);
}
.syntax-help .chips { display: flex; flex-wrap: wrap; gap: 6px; margin-top: 4px; }
.disclaimer {
    margin-top: 8px;
    padding: 12px;
    background: var(--accent-warning-dim);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    font-size: 0.8rem;
    color: var(--text-secondary);
}

/* --- responsive --- */
@media (max-width: 900px) {
    .calculator-layout { grid-template-columns: 1fr; }
    #resultValue { font-size: 1.9rem; }
    .vars-head { display: none; }
    .var-row {
        grid-template-columns: 1fr 1fr;
        gap: 8px 10px;
        padding: 12px;
        border: 1px solid var(--border-color);
        border-radius: 10px;
        background: var(--bg-secondary);
    }
    .var-name { grid-column: 1 / -1; }
    .var-mode { grid-column: 1 / -1; }
}