/* Gentzen Tree Renderer */

.gentzen-container {
    border: 1px solid var(--border);
    border-radius: 10px;
    background: var(--bg-raised);
    overflow: hidden;
    margin: 2rem 0;
}

.gentzen-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 0.75rem 1rem;
    background: var(--code-bg);
    border-bottom: 1px solid var(--border);
    font-family: var(--mono);
    font-size: 0.8rem;
    color: var(--text-muted);
}

.gentzen-title {
    color: var(--accent);
}

.gentzen-counter {
    color: var(--text-muted);
}

/* Tree area */
.gentzen-tree-area {
    padding: 2rem 1.5rem;
    display: flex;
    justify-content: center;
    align-items: flex-end;
    min-height: 200px;
    overflow-x: auto;
}

/* Inference node */
.gentzen-inference {
    display: flex;
    flex-direction: column;
    align-items: center;
    transition: opacity 0.3s ease;
}

.gentzen-inference.highlight {
    background: rgba(126, 184, 218, 0.06);
    border-radius: 8px;
}

/* Premises row */
.gentzen-premises {
    display: flex;
    align-items: flex-end;
    justify-content: center;
    gap: 0;
}

.gentzen-premise-spacer {
    width: 2rem;
    flex-shrink: 0;
}

/* Horizontal inference bar */
.gentzen-bar-row {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    width: 100%;
    margin: 0.25rem 0;
}

.gentzen-bar {
    flex: 1;
    height: 2px;
    background: var(--text);
    min-width: 3rem;
}

.gentzen-rule {
    font-family: var(--mono);
    font-size: 0.7rem;
    color: var(--accent);
    white-space: nowrap;
    cursor: pointer;
    padding: 0.1rem 0.3rem;
    border-radius: 3px;
    transition: background 0.2s;
}

.gentzen-rule:hover {
    background: rgba(126, 184, 218, 0.12);
}

.gentzen-discharge-mark {
    font-size: 0.6rem;
    color: #c9a0dc;
    margin-left: 1px;
}

/* Conclusion (below the bar) */
.gentzen-conclusion {
    padding: 0.25rem 0.5rem;
    text-align: center;
}

/* Leaf node */
.gentzen-leaf {
    padding: 0.25rem 0.5rem;
    text-align: center;
    white-space: nowrap;
}

.gentzen-label {
    font-family: var(--mono);
    font-size: 0.75rem;
    color: var(--accent);
}

/* Formula text */
.gentzen-formula {
    font-family: var(--serif);
    font-size: 1.1rem;
    color: var(--text);
}

.gentzen-formula .sym {
    color: var(--accent);
    padding: 0 0.1em;
}

/* Assumption brackets [P]^n */
.gentzen-assumption-bracket {
    font-family: var(--serif);
    font-size: 1.1rem;
    color: #c9a0dc;
}

/* Info panel */
.gentzen-info-panel {
    padding: 1rem 1.25rem;
    border-top: 1px solid var(--border);
    min-height: 3.5rem;
}

.gentzen-rule-display {
    font-family: var(--mono);
    font-size: 0.9rem;
    color: #c9a0dc;
    margin-bottom: 0.25rem;
}

.gentzen-rule-tag {
    background: rgba(201, 160, 220, 0.15);
    padding: 0.15rem 0.5rem;
    border-radius: 4px;
    font-weight: 500;
}

.gentzen-step-label {
    color: var(--text-muted);
    font-weight: 400;
}

.gentzen-explanation {
    font-size: 0.85rem;
    color: var(--text-muted);
    line-height: 1.5;
}

/* Lean tactic mapping */
.gentzen-lean-mapping {
    margin-top: 0.5rem;
    padding-top: 0.5rem;
    border-top: 1px dashed var(--border);
    font-size: 0.8rem;
    color: var(--text-muted);
}

.gentzen-lean-mapping .mapping-label {
    font-family: var(--mono);
    color: var(--accent-dim);
    font-size: 0.7rem;
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.gentzen-lean-mapping code {
    font-family: var(--mono);
    color: #c9a0dc;
    background: var(--code-bg);
    padding: 0.1rem 0.4rem;
    border-radius: 3px;
    font-size: 0.85rem;
}

/* Animation for tree building */
.gentzen-inference {
    animation: gentzen-appear 0.4s ease;
}

@keyframes gentzen-appear {
    from {
        opacity: 0;
        transform: translateY(8px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* Responsive */
@media (max-width: 640px) {
    .gentzen-tree-area {
        padding: 1.5rem 1rem;
        min-height: 150px;
    }
    .gentzen-formula {
        font-size: 0.95rem;
    }
    .gentzen-premise-spacer {
        width: 1rem;
    }
}