/* Theme */
/* Dark */
:root {
    --bg: #0f1726;
    --bg-soft: #141b2d;
    --bg-glass: #1a2238;
    --bg-grey: #222a42;

    --border-glass: #2f3a5f;

    --bg-title: #a6abc4;
    --bg-tree-line: #9aa0b5;
    --bg-concl-input: #3e4563;

    --text: #e6edf3;
    --text-muted: #9da7b3;

    --accent: #4ea1ff;
    --accent-soft: #244468;

    --ok: #34d399;
    --err: #f87171;
    --warn: #fbbf24;

    --radius: 14px;
}

/* Light (default) */
:root[data-theme="light"] {
    --bg: #f4f6fa;
    --bg-soft: #fafbfc;
    --bg-glass: #ffffff;
    --bg-grey: #eef1f6;

    --border-glass: #dde2ea;

    --bg-title: #1f2937;
    --bg-tree-line: #374151;
    --bg-concl-input: #e9edf3;

    --text: #111827;
    --text-muted: #6b7280;

    --accent: #2563eb;
    --accent-soft: #dbeafe;

    --ok: #059669;
    --err: #dc2626;
    --warn: #d97706;

    color-scheme: light;
}

:root[data-theme="dark"] {
    color-scheme: dark;
}

/* Body */
html,
body {
    margin: 0;
    padding: 0;
    height: 100%;
    background-color: var(--bg);
    color: var(--text);
    font-family: Inter, system-ui, sans-serif;
}

* {
    box-sizing: border-box;
}

/* Smooth theme switching*/
body,
.sidebar,
.panel,
.main,
.titleblock,
input,
button,
.icon-btn,
.conclusion-input {
    transition:
        background-color 0.2s ease,
        color 0.2s ease,
        border-color 0.2s ease,
        box-shadow 0.2s ease;
}

.hidden {
    display: none;
}

/* App */

.app {
    display: grid;
    background: var(--bg);
    grid-template-columns: minmax(100px, 170px) minmax(0, 1fr) minmax(100px, 170px);
    height: 100vh;
    gap: 12px;
    padding: 12px;
    grid-template-rows: 1fr auto;
}

/* Sidebar */

.sidebar,
.panel {
    background: var(--bg-glass);
    border: 1px solid var(--border-glass);
    border-radius: var(--radius);
    padding: 14px;
    overflow-y: auto;
    overflow-x: hidden;
    min-width: 0;
}

.sidebar h2,
.panel h2 {
    margin: 0 0 10px;
    font-size: 0.9rem;
    font-weight: 600;
    color: var(--text-muted);
    letter-spacing: 0.04em;
    text-transform: uppercase;
}

.panel {
    border-left: 1px solid var(--border-glass);
}

/* Main */
.main {
    display: flex;
    flex-direction: column;
    height: 100%;
    min-width: 0;
    border-radius: var(--radius);
    overflow: hidden;
    background: var(--bg-soft);
}

/* Titleblock */

.titleblock {
    display: flex;
    flex-direction: column;
    background: var(--bg-glass);
    border: 1px solid var(--border-glass);
    border-radius: 18px;
    overflow: hidden;
    box-shadow: 0 8px 24px rgba(0, 0, 0, 0.25);
}

:root[data-theme="light"] .titleblock {
    box-shadow: 0 6px 18px rgba(17, 24, 39, 0.06);
}

.title,
.actionbar,
.toolbar {
    padding: 14px 18px;
    background: transparent;
    border-bottom: 1px solid var(--border-glass);
}

/* Inputs */
input {
    background: var(--bg-grey);
    border: 1px solid var(--border-glass);
    border-radius: 8px;
    padding: 6px 8px;
    color: var(--text);
    outline: none;
}

input::placeholder {
    color: var(--text-muted);
}

input:focus {
    border-color: var(--accent);
    box-shadow: 0 0 0 2px var(--accent-soft);
}

/* Keyboard navigation stays visible */
button:focus-visible,
a:focus-visible {
    outline: 2px solid var(--accent);
    outline-offset: 2px;
}

/* Actionbar, Toolbar */
.actionbar {
    display: flex;
    gap: 8px;
    flex-wrap: wrap;
    justify-content: center;
}

.actionbar button {
    background: var(--bg-grey);
    border: 1px solid var(--border-glass);
    border-radius: 8px;
    padding: 6px 12px;
    color: var(--text-muted);
    cursor: pointer;
    transition: all 0.15s ease;
}

.actionbar button:hover {
    color: var(--text);
    border-color: var(--accent);
    background: var(--accent-soft);
}

.actionbar button:active {
    transform: scale(0.97);
}

.toolbar {
    display: flex;
    gap: 12px;
    align-items: center;
}

.toolbar input {
    background: var(--bg-grey);
    border: 1px solid var(--border-glass);
    border-radius: 8px;
    padding: 6px 10px;
    color: var(--text);
}

/* Title */

.title {
    display: grid;
    grid-template-columns: 1fr auto 1fr;
    align-items: center;
    font-size: 0.4rem;
}

.app-title .brand {
    font-weight: 900;
    font-size: 2.5rem;
    background: rgb(78, 75, 120);
    -webkit-background-clip: text;
    background-clip: text;
    color: transparent;
}

.title-buttons {
    display: flex;
    gap: 12px;
    justify-self: end;
}

.icon-btn {
    background: var(--bg-grey);
    border: 1px solid var(--border-glass);
    border-radius: 40px;
    width: 40px;
    height: 40px;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    transition: all 0.2s ease;
    color: var(--text);
    font-size: 0.95rem;
}

.icon-btn:hover {
    background: var(--accent-soft);
    border-color: var(--accent);
    transform: scale(1.05);
}

.icon-btn:active {
    transform: scale(0.95);
}
.manual-btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    justify-self: start;

    padding: 4px 20px;
    font-size: 1rem;

    background: var(--bg-grey);
    border: 1px solid var(--border-glass);
    border-radius: 8px;

    color: var(--text-muted);
    text-decoration: none;

    font-weight: 500;
    transition: all 0.2s ease;
}

.manual-btn:hover,
.manual-btn:focus,
.manual-btn:visited {
    text-decoration: none;
}

.manual-btn:hover {
    color: var(--accent);
    border-color: var(--accent);
    background: var(--accent-soft);
}

.title h2 {
    margin: 0;
    font-size: 1.9rem;
    font-weight: 800;
    color: var(--bg-title);
    text-align: center;
}

.title-placeholder {
    width: 80px;
    visibility: hidden;
}

/* Canvas */
.viewport {
    overflow: hidden;
    position: relative;
    flex: 1;
}

#canvas {
    display: inline-block;
    width: max-content;
}

#proofViewport {
    flex: 1 1 auto;
    min-width: 0;
    overflow: hidden;
    position: relative;
    background: transparent;

    cursor: grab;
    touch-action: none;
    overscroll-behavior: contain;
}

#proofViewport.panning {
    cursor: grabbing;
}

#proofViewport.panning,
#proofViewport.panning * {
    user-select: none;
}

#transformLayer {
    transform-origin: 0 0;
    position: relative;
    width: 100%;
    height: 100%;
    will-change: transform;
}

/* Rulebuttons */
#rules button {
    display: block;
    width: 100%;
    margin-bottom: 6px;
    padding: 8px 10px;

    background: var(--bg-grey);
    color: var(--text);

    border: 1px solid var(--border-glass);
    border-radius: 10px;

    cursor: pointer;
    transition: all 0.15s ease;
}

#rules button:hover {
    background: var(--bg-soft);
    border-color: var(--accent);
}

#rules button:active {
    transform: scale(0.98);
}

/* Prooftree */
.proof-tree {
    padding: 20px;
    overflow: visible;
}

.tree-node {
    display: flex;
    flex-direction: column;
    align-items: center;
}

.premises {
    display: flex;
    justify-content: center;
    align-items: flex-end;
    gap: 25px;
    margin-bottom: 6px;
    font-size: 2rem;
}

/* Rule line */

.rule-line {
    display: flex;
    align-items: center;
}

.rule-line .line {
    width: 1px;
    height: 2px;
    background: var(--bg-tree-line);
    transform: translateZ(0);
    will-change: transform;
}

.rule-line .rule-label {
    font-size: 0.65rem;
    margin-left: 5px;
}

/* Conclusion input */

.conclusion-input {
    margin: 7px 0;
    border-radius: 6px;
    text-align: center;
    min-width: 80px;
    background: var(--bg-grey);
    padding: 10px 20px;
    cursor: text;
}

/* Selected node: shows where the next rule will be applied */
.tree-node.selected > .conclusion-input {
    border-color: var(--accent);
    box-shadow: 0 0 0 2px var(--accent-soft);
}

/* Formula doesn't parse */
.conclusion-input.invalid {
    border-color: var(--err);
}

/* Invalid formula takes priority over the selection highlight */
.tree-node.selected > .conclusion-input.invalid {
    border-color: var(--err);
    box-shadow: 0 0 0 2px color-mix(in srgb, var(--err) 25%, transparent);
}

.tree-node input {
    padding: 4px;
}

/* Result panel */

.result-card {
    display: flex;
    flex-direction: column;
    gap: 4px;
    padding: 12px 14px;
    border: 1px solid var(--border-glass);
    border-radius: 8px;
    background: var(--bg-grey);
    transition: all 0.15s ease;
}

.result-status {
    font-size: 0.85rem;
    font-weight: 700;
    letter-spacing: 0.03em;
    text-transform: uppercase;
    color: var(--text);
}

.result-detail {
    font-size: 0.78rem;
    line-height: 1.4;
    color: var(--text-muted);
}

.result-card.ghost .result-status {
    color: var(--text-muted);
    font-style: italic;
}

.result-card.ok {
    border-color: color-mix(in srgb, var(--ok) 30%, var(--bg-grey));
    background: color-mix(in srgb, var(--ok) 7%, var(--bg-grey));
}

.result-card.ok .result-status {
    color: color-mix(in srgb, var(--ok) 70%, var(--bg-grey));
}

.result-card.err {
    border-color: color-mix(in srgb, var(--err) 30%, var(--bg-grey));
    background: color-mix(in srgb, var(--err) 7%, var(--bg-grey));
}

.result-card.err .result-status {
    color: color-mix(in srgb, var(--err) 70%, var(--bg-grey));
}

.result-card.warn {
    border-color: color-mix(in srgb, var(--warn) 30%, var(--bg-grey));
    background: color-mix(in srgb, var(--warn) 7%, var(--bg-grey));
}

.result-card.warn .result-status {
    color: color-mix(in srgb, var(--warn) 70%, var(--bg-grey));
}

/* Split right panel */

.split-panel {
    display: flex;
    flex-direction: column;
    padding: 0;
}

.panel-section {
    flex: 1;
    padding: 12px;
    overflow-y: auto;
}

.panel-section + .panel-section {
    border-top: 1px solid var(--border-glass);
}

.divider {
    height: 1px;
    background: var(--border-glass);
    margin: 16px -12px;
}

/* Help styling */

.symbol-help {
    display: flex;
    flex-direction: column;
    gap: 6px;
}

.symbol-help code,
.syntax-help code {
    background: var(--bg-grey);
    padding: 2px 6px;
    border-radius: 6px;
    font-size: 0.8rem;
    color: var(--text);
}

.symbol-help div,
.syntax-help div {
    margin-bottom: 6px;
    font-size: 0.8rem;
    color: var(--text-muted);
}
.convert-help {
    display: flex;
    flex-direction: column;
    gap: 10px;
    text-align: left;
}

.convert-item {
    display: flex;
    flex-direction: column;
    gap: 8px;
    background: var(--bg-soft);
    border: 1px solid var(--border-glass);
    border-radius: 8px;
    padding: 10px;
    transition: border-color 0.2s ease;
}

.convert-row {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 8px;
}

.convert-row a {
    font-size: 0.85rem;
    font-weight: 500;
    color: var(--accent);
    text-decoration: none;
}

.convert-row a:hover {
    text-decoration: underline;
}

.convert-tag {
    font-size: 0.6rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.04em;
    padding: 2px 8px;
    border-radius: 20px;
    border: 1px solid var(--border-glass);
}

.tag-typst {
    color: #3dbdd1;
    background: color-mix(in srgb, #3dbdd1 12%, transparent);
    border-color: color-mix(in srgb, #3dbdd1 25%, transparent);
}

.tag-latex {
    color: var(--ok);
    background: color-mix(in srgb, var(--ok) 12%, transparent);
    border-color: color-mix(in srgb, var(--ok) 25%, transparent);
}

.copy-btn {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 6px;
    width: 100%;
    background: var(--bg-grey);
    border: 1px solid var(--border-glass);
    border-radius: 6px;
    padding: 6px 8px;
    font-size: 0.72rem;
    color: var(--text-muted);
    cursor: pointer;
    transition: all 0.15s ease;
    font-family: inherit;
}

.copy-btn:hover {
    background: var(--accent-soft);
    border-color: var(--accent);
    color: var(--accent);
}

.copy-btn.copied {
    background: color-mix(in srgb, var(--ok) 12%, transparent);
    border-color: var(--ok);
    color: var(--ok);
    pointer-events: none;
}

/* Accessibility: respect users who disable animations */
@media (prefers-reduced-motion: reduce) {
    * {
        transition: none;
    }
}

/* Footer */

.footer {
    grid-column: 1 / -1;
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: 4px 16px;
    padding: 7px 16px;
    background: var(--bg-glass);
    border: 1px solid var(--border-glass);
    border-radius: var(--radius);
    font-size: 0.72rem;
    color: var(--text-muted);
    letter-spacing: 0.02em;
}

.footer-group {
    display: flex;
    align-items: center;
    flex-wrap: wrap;
}

.footer-logo {
    width: 16px;
    height: 16px;
    margin-right: 7px;
    border-radius: 3px;
    object-fit: contain;
    vertical-align: middle;
}

.footer-brand {
    font-weight: 600;
    color: var(--text-muted);
}

.footer-sep {
    margin: 0 9px;
    opacity: 0.45;
    user-select: none;
}

.footer a {
    color: var(--text-muted);
    text-decoration: none;
    border-bottom: 1px dotted transparent;
    transition:
        color 0.15s ease,
        border-color 0.15s ease;
}

.footer-icon {
    display: inline-flex;
    align-items: center;
}

.footer a:hover {
    color: var(--accent);
    border-bottom-color: var(--accent);
}