/*
 * proof-tree.css — Standalone proof tree component styles
 *
 * Self-contained: uses --pt-* custom properties so it works
 * without any other stylesheet. Override variables to theme.
 */

/* ── Beautiful ⇓ rendering ────────────────────────── */

/* Proof tree nodes: ⇓ wrapped in .pt-darr spans by JS */
.pt-darr {
    font-family: 'Palatino', 'Palatino Linotype', 'Book Antiqua', 'Georgia', 'Times New Roman', serif;
    font-size: 1.15em;
    vertical-align: -0.03em;
    letter-spacing: 0.02em;
}

/* Prose text: use serif font for ⇓ via unicode-range */
@font-face {
    font-family: 'Darr';
    src: local('Palatino'), local('Palatino Linotype'), local('Book Antiqua'),
         local('Georgia'), local('Times New Roman');
    unicode-range: U+21D3;
}

body {
    font-family: 'Darr', 'Open Sans', sans-serif;
}

:root {
    --pt-primary: #4f46e5;
    --pt-danger: #ef4444;
    --pt-warn: #d97706;
    --pt-gray-100: #f3f4f6;
    --pt-gray-200: #e5e7eb;
    --pt-gray-300: #d1d5db;
    --pt-gray-400: #9ca3af;
    --pt-gray-700: #374151;
    --pt-gray-900: #111827;
    --pt-radius: 8px;
}

/* ── Viewport / zoom wrapper ───────────────────────── */
.proof-tree-viewport {
    overflow: hidden;
    position: relative;
    min-height: 80px;
    cursor: grab;
    touch-action: none;
}

.proof-tree-viewport:active {
    cursor: grabbing;
}

.proof-tree-canvas {
    transform-origin: 0 0;
    display: flex;
    justify-content: center;
    padding: 16px 20px;
    min-height: 60px;
}

.proof-tree-zoom-controls {
    display: flex;
    align-items: center;
    gap: 6px;
    position: absolute;
    bottom: 8px;
    right: 12px;
    background: rgba(255, 255, 255, 0.92);
    border: 1px solid var(--pt-gray-200);
    border-radius: var(--pt-radius);
    padding: 4px 8px;
    font-size: 0.75rem;
    z-index: 5;
    user-select: none;
}

.proof-tree-zoom-controls button {
    background: none;
    border: 1px solid var(--pt-gray-300);
    border-radius: 4px;
    min-width: 26px;
    height: 26px;
    padding: 0 6px;
    cursor: pointer;
    font-size: 0.85rem;
    font-weight: 600;
    color: var(--pt-gray-700);
    display: flex;
    align-items: center;
    justify-content: center;
    white-space: nowrap;
    transition: background 0.12s, border-color 0.12s;
}

.proof-tree-zoom-controls button:hover {
    background: var(--pt-gray-100);
    border-color: var(--pt-gray-400);
}

.proof-tree-zoom-label {
    min-width: 36px;
    text-align: center;
    color: var(--pt-gray-700);
    font-weight: 500;
}

/* ── Node: column of premises → line → conclusion ── */
.proof-node {
    display: inline-flex;
    flex-direction: column;
    align-items: center;
    padding: 0 1px;
}

/* Premises sit in a row; the trailing "+" button lives here too */
.proof-premises {
    display: flex;
    flex-direction: row;
    gap: 10px;
    align-items: flex-end;
    margin-bottom: 2px;
}

/* The "+" button that trails the last premise */
.proof-add-premise {
    align-self: flex-end;
    margin-bottom: 4px;
    opacity: 0;
    transition: opacity 0.15s;
    font-size: 0.85rem;
}

.proof-node:hover > .proof-premises > .proof-add-premise {
    opacity: 1;
}

/* ── Inference line row ────────────────────────────── */
.proof-inference {
    display: flex;
    flex-direction: row;
    align-items: center;
    align-self: stretch;
    position: relative;
    margin: 2px 0;
}

.proof-line {
    flex: 1;
    height: 1.5px;
    background: var(--pt-gray-900);
    min-width: 30px;
}

/* ── Rule labels: inline flex children beside the line ── */
.proof-rule-label {
    font-size: 0.8rem;
    font-variant: small-caps;
    letter-spacing: 0.04em;
    color: var(--pt-gray-700);
    white-space: nowrap;
    cursor: pointer;
    padding: 2px 4px;
    border-radius: 3px;
    transition: color 0.12s, background 0.12s;
    flex-shrink: 0;
}

.proof-rule-left {
    margin-right: 6px;
}

.proof-rule-right {
    margin-left: 6px;
}

.proof-rule-label:hover {
    color: var(--pt-primary);
    background: rgba(79, 70, 229, 0.06);
}

/* Empty labels: faint italic placeholder */
.proof-rule-placeholder {
    color: var(--pt-gray-300);
    font-style: italic;
    font-variant: normal;
    font-size: 0.72rem;
    letter-spacing: 0;
}

/* Left placeholder hidden until node is hovered (rarely used) */
.proof-rule-left.proof-rule-placeholder {
    display: none;
}

.proof-node:hover > .proof-inference .proof-rule-left.proof-rule-placeholder {
    display: inline;
}

.proof-rule-placeholder:hover {
    color: var(--pt-primary);
    background: rgba(79, 70, 229, 0.06);
}

/* ── Axiom nodes (0-premise rules) ───────────────── */
/* Axiom rule labels are still clickable in the editor */

.proof-readonly .proof-rule-label {
    cursor: default;
}

.proof-readonly .proof-rule-label:hover {
    color: var(--pt-gray-700);
    background: transparent;
}

.proof-readonly .proof-rule-placeholder {
    display: none;
}

/* ── Action buttons on inference line (absolutely positioned) ── */
.proof-line-btns {
    position: absolute;
    top: 50%;
    transform: translateY(-50%);
    right: -2px;
    display: flex;
    gap: 2px;
    opacity: 0;
    transition: opacity 0.15s;
}

.proof-node:hover > .proof-inference > .proof-line-btns {
    opacity: 1;
}

/* ── Conclusion formula ────────────────────────────── */
.proof-conclusion {
    padding: 3px 4px;
    text-align: center;
    font-size: 1rem;
    letter-spacing: 0.01em;
    cursor: pointer;
    border-radius: 3px;
    transition: background 0.12s;
    white-space: nowrap;
    min-height: 1.4em;
    margin-top: 1px;
}

.proof-conclusion:hover {
    background: rgba(79, 70, 229, 0.07);
}

.proof-readonly .proof-conclusion {
    cursor: default;
    padding: 3px 6px;
}

.proof-readonly .proof-conclusion:hover {
    background: transparent;
}

.proof-formula {
    cursor: pointer;
}

/* Empty formula: italic placeholder text */
.proof-formula-placeholder {
    color: var(--pt-gray-400);
    font-style: italic;
    font-size: 0.88rem;
    cursor: pointer;
    user-select: none;
}

.proof-formula-placeholder:hover {
    color: var(--pt-primary);
}

/* ── Leaf zone: "apply rule" above the conclusion ─── */
.proof-leaf-zone {
    display: flex;
    gap: 4px;
    justify-content: center;
    min-height: 20px;
    align-items: center;
}

.proof-leaf-zone > .proof-action-btn {
    opacity: 0;
    transition: opacity 0.15s;
}

.proof-node:hover > .proof-leaf-zone > .proof-action-btn {
    opacity: 1;
}

/* ── Inline editing inputs ─────────────────────────── */
.proof-formula-edit {
    border: 1.5px solid var(--pt-primary);
    border-radius: 3px;
    padding: 2px 8px;
    font-size: 0.95rem;
    outline: none;
    min-width: 80px;
    text-align: center;
    background: white;
    box-shadow: 0 0 0 2px rgba(79, 70, 229, 0.12);
}

.proof-rule-edit {
    border: 1.5px solid var(--pt-primary);
    border-radius: 3px;
    padding: 1px 6px;
    font-size: 0.8rem;
    font-variant: small-caps;
    letter-spacing: 0.04em;
    outline: none;
    min-width: 50px;
    max-width: 120px;
    background: white;
    box-shadow: 0 0 0 2px rgba(79, 70, 229, 0.12);
}

/* ── Action buttons ────────────────────────────────── */
.proof-action-btn {
    background: none;
    border: none;
    padding: 2px 6px;
    font-size: 0.7rem;
    font-weight: 600;
    letter-spacing: 0.02em;
    text-transform: uppercase;
    cursor: pointer;
    color: var(--pt-gray-400);
    border-radius: 3px;
    transition: color 0.12s, background 0.12s;
    white-space: nowrap;
}

.proof-action-btn:hover {
    color: var(--pt-primary);
    background: rgba(79, 70, 229, 0.08);
}

.proof-action-btn.proof-action-disabled {
    opacity: 0.35;
    cursor: not-allowed;
}

.proof-action-btn.proof-action-disabled:hover {
    color: var(--pt-gray-400);
    background: none;
}

.proof-action-remove:hover {
    color: var(--pt-danger);
    background: rgba(239, 68, 68, 0.08);
}

.proof-action-clear:hover {
    color: var(--pt-warn);
    background: rgba(217, 119, 6, 0.08);
}

/* ── Orientation hint ─────────────────────────────── */
.proof-tree-orientation-hint {
    display: none;
    text-align: center;
    padding: 8px 12px;
    font-size: 0.8rem;
    color: var(--pt-gray-700);
    background: var(--pt-gray-100);
    border: 1px solid var(--pt-gray-200);
    border-radius: var(--pt-radius);
    margin-bottom: 8px;
}

/* ── Mobile / touch ──────────────────────────────── */
@media (max-width: 640px) {
    .proof-tree-canvas {
        padding: 14px 6px;
    }

    .proof-premises {
        gap: 6px;
    }

    .proof-conclusion {
        font-size: 0.92rem;
        padding: 6px 10px;
        min-height: 2em;
    }

    /* Larger touch targets for action buttons */
    .proof-action-btn {
        padding: 6px 10px;
        font-size: 0.8rem;
        min-height: 32px;
    }

    /* Always show actions on touch devices */
    .proof-add-premise,
    .proof-leaf-zone > .proof-action-btn,
    .proof-line-btns {
        opacity: 1 !important;
    }

    /* Larger inline edit inputs for on-screen keyboards */
    .proof-formula-edit {
        font-size: 1rem;
        padding: 6px 10px;
        min-width: 100px;
    }

    .proof-rule-edit {
        font-size: 0.9rem;
        padding: 4px 8px;
        min-width: 60px;
    }

    /* Compact zoom controls */
    .proof-tree-zoom-controls {
        gap: 4px;
        padding: 3px 6px;
        bottom: 4px;
        right: 4px;
    }

    .proof-tree-zoom-controls button {
        min-width: 32px;
        height: 32px;
        font-size: 0.8rem;
    }

    .proof-tree-zoom-label {
        min-width: 32px;
        font-size: 0.7rem;
    }
}

/* Portrait on narrow screens: show orientation hint */
@media (max-width: 640px) and (orientation: portrait) {
    .proof-tree-orientation-hint {
        display: block;
    }
}

/* Landscape on narrow screens: hide it */
@media (max-width: 640px) and (orientation: landscape) {
    .proof-tree-orientation-hint {
        display: none;
    }
}

/* ── Rule autocomplete dropdown ──────────────────── */
.proof-rule-ac-wrap {
    position: relative;
    flex-shrink: 0;
    margin-left: 6px;
    z-index: 20;
    white-space: nowrap;
}

.proof-rule-dropdown {
    position: absolute;
    top: 100%;
    left: 0;
    z-index: 50;
    min-width: 120px;
    max-height: 200px;
    overflow-y: auto;
    background: white;
    border: 1px solid var(--pt-gray-300);
    border-radius: 6px;
    box-shadow: 0 6px 20px rgba(0,0,0,0.15);
    margin-top: 2px;
    font-size: 0.8rem;
    font-variant: normal;
    letter-spacing: 0;
    overflow-x: visible;
}

.proof-rule-dropdown-item {
    padding: 5px 10px;
    cursor: pointer;
    white-space: nowrap;
    color: var(--pt-gray-700);
    transition: background 0.1s;
}

.proof-rule-dropdown-item:hover,
.proof-rule-dropdown-item.selected {
    background: rgba(79, 70, 229, 0.08);
    color: var(--pt-primary);
}

.proof-rule-dropdown-item.proof-rule-disabled {
    color: var(--pt-gray-300);
    font-style: italic;
}

.proof-rule-dropdown-item.proof-rule-disabled:hover {
    color: var(--pt-gray-400);
    background: rgba(0, 0, 0, 0.03);
}

@media (max-width: 640px) {
    .proof-rule-dropdown {
        min-width: 100px;
        max-height: 160px;
        font-size: 0.85rem;
    }
    .proof-rule-dropdown-item {
        padding: 8px 12px;
        min-height: 32px;
    }
}

/* ── Floating autocomplete (shown on leaf before restructuring) ── */
.proof-floating-ac {
    position: absolute;
    top: 50%;
    left: 100%;
    transform: translateY(-50%);
    z-index: 60;
    white-space: nowrap;
    margin-left: 8px;
}

.proof-floating-ac .proof-rule-edit {
    display: block;
}

.proof-floating-ac .proof-rule-dropdown {
    position: absolute;
    top: 100%;
    left: 0;
}

/* ── Rule error tooltip ───────────────────────────── */
.proof-rule-error-tip {
    background: #fef2f2;
    color: #991b1b;
    border: 1px solid #fecaca;
    border-radius: 6px;
    padding: 6px 12px;
    font-size: 0.8em;
    line-height: 1.4;
    margin-top: 4px;
    max-width: 400px;
    cursor: pointer;
    animation: proof-error-fade-in 0.2s ease;
    position: relative;
    z-index: 10;
}
.proof-rule-error-tip::before {
    content: "\2717 ";
    font-weight: 600;
}
@keyframes proof-error-fade-in {
    from { opacity: 0; transform: translateY(-4px); }
    to { opacity: 1; transform: translateY(0); }
}

/* ── Ligature hints panel ────────────────────────── */
.pt-ligature-hints {
    opacity: 0;
    max-height: 0;
    overflow: hidden;
    transition: opacity 0.35s ease, max-height 0.35s ease, padding 0.35s ease;
    padding: 0 16px;
    margin-top: 0;
    border-top: 1px solid transparent;
    pointer-events: none;
    font-size: 0.78rem;
    color: var(--pt-gray-700);
    user-select: none;
}

.pt-ligature-hints.pt-lh-visible {
    opacity: 1;
    max-height: 120px;
    padding: 10px 16px 8px;
    border-top: 1px solid var(--pt-gray-200);
    pointer-events: auto;
}

.pt-lh-title {
    font-size: 0.65rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.08em;
    color: var(--pt-gray-400);
    margin-bottom: 6px;
}

.pt-lh-cols {
    display: flex;
    gap: 20px;
    flex-wrap: wrap;
}

.pt-lh-col {
    display: flex;
    flex-direction: column;
    gap: 2px;
}

.pt-lh-row {
    display: flex;
    align-items: center;
    gap: 4px;
    white-space: nowrap;
    line-height: 1.5;
}

.pt-lh-row kbd {
    display: inline-block;
    background: var(--pt-gray-100);
    border: 1px solid var(--pt-gray-200);
    border-radius: 3px;
    padding: 0 4px;
    font-family: 'SF Mono', 'Fira Code', 'Cascadia Code', monospace;
    font-size: 0.85em;
    min-width: 20px;
    text-align: center;
    color: var(--pt-gray-700);
}

.pt-lh-arrow {
    font-size: 0.7em;
    color: var(--pt-gray-300);
}

@media (max-width: 640px) {
    .pt-lh-cols {
        gap: 12px;
    }
    .pt-ligature-hints.pt-lh-visible {
        max-height: 200px;
    }
}