/*!
 * Mermaid Editor stylesheet
 *
 * Includes former shared base.css foundations plus app-specific styles.
 */

/* ── Design tokens ───────────────────────────────────────────────────────── */
:root {
    --color-primary:      #2563eb;   /* blue-600  */
    --color-primary-dark: #1d4ed8;   /* blue-700  */
    --color-surface:      #ffffff;
    --color-bg:           #f9fafb;   /* gray-50   */
    --color-border:       #e5e7eb;   /* gray-200  */
    --color-text:         #1f2937;   /* gray-800  */
    --color-text-muted:   #6b7280;   /* gray-500  */
    --radius-card:        0.75rem;
    --shadow-card:        0 1px 3px rgba(0,0,0,.08), 0 1px 2px rgba(0,0,0,.04);
    --editor-header-h:      52px;
    --editor-toolbar-h:     40px;
    --editor-tabs-h:        40px;
    --editor-status-h:      26px;
    --pane-splitter-w:      5px;
    --toolbar-bg:           #f3f4f6;
    --toolbar-border:       #e5e7eb;
    --tab-bar-bg:           #dde1e7;
    --tab-inactive-bg:      #eceef1;
    --tab-active-bg:        #dbeafe;
    --tab-active-color:     #1d4ed8;
    --editor-bg:            #fafafa;
    --preview-bg:           #f1f5f9;
    --btn-color:            #374151;
    --btn-hover-bg:         #e5e7eb;
    --btn-active-bg:        #dbeafe;
    --btn-active-color:     #1d4ed8;
    --save-btn-bg:          #2563eb;
    --save-btn-hover:       #1d4ed8;
    --save-btn-color:       #fff;
    --dropdown-bg:          #fff;
    --dropdown-border:      #e5e7eb;
    --dropdown-hover:       #f3f4f6;
    --status-bg:            #f9fafb;
    --status-text:          #6b7280;
    --error-bg:             #fef2f2;
    --error-text:           #dc2626;
    --drop-overlay-bg:      rgba(59, 130, 246, 0.12);
    --drop-overlay-border:  #3b82f6;
}


body.dark {
    --color-surface:    #2d3748;
    --color-bg:         #1f2937;
    --color-border:     #4b5563;
    --color-text:       #e5e7eb;
    --color-text-muted: #9ca3af;
    --toolbar-bg:           #1e2533;
    --toolbar-border:       #374151;
    --editor-bg:            #1a1f2e;
    --preview-bg:           #111827;
    --btn-color:            #d1d5db;
    --btn-hover-bg:         #374151;
    --btn-active-bg:        #1e3a5f;
    --btn-active-color:     #93c5fd;
    --save-btn-bg:          #1d4ed8;
    --save-btn-hover:       #2563eb;
    --save-btn-color:       #fff;
    --dropdown-bg:          #1e2533;
    --dropdown-border:      #374151;
    --dropdown-hover:       #374151;
    --status-bg:            #1a1f2e;
    --status-text:          #9ca3af;
    --error-bg:             #2d1515;
    --error-text:           #f87171;
    --tab-bar-bg:           #0f1520;
    --tab-inactive-bg:      #1e2533;
    --tab-active-bg:        #1e3a5f;
    --tab-active-color:     #bfdbfe;
}

/* ── Scrollbar ───────────────────────────────────────────────────────────── */
::-webkit-scrollbar       { width: 8px; height: 8px; }
::-webkit-scrollbar-track { background: #f1f1f1; }
::-webkit-scrollbar-thumb { background: #c1c1c1; border-radius: 4px; }
::-webkit-scrollbar-thumb:hover { background: #a8a8a8; }

body.dark ::-webkit-scrollbar-track { background: #2d3748; }
body.dark ::-webkit-scrollbar-thumb { background: #4b5563; }
body.dark ::-webkit-scrollbar-thumb:hover { background: #6b7280; }

/* ── Utility ─────────────────────────────────────────────────────────────── */
[v-cloak] { display: none; }

/* ── Layout ──────────────────────────────────────────────────────────────── */
*, *::before, *::after { box-sizing: border-box; }
html, body { height: 100%; margin: 0; overflow: hidden; }

body {
    display: flex;
    flex-direction: column;
    background: var(--color-bg);
    color: var(--color-text);
    font-family: ui-sans-serif, system-ui, -apple-system, sans-serif;
}

/* ── App header ──────────────────────────────────────────────────────────── */
.app-header {
    height: var(--editor-header-h);
    background: var(--color-surface);
    border-bottom: 1px solid var(--color-border);
    display: flex;
    align-items: center;
    padding: 0 16px;
    gap: 12px;
    flex-shrink: 0;
    z-index: 30;
}

.app-header-title {
    display: flex;
    align-items: center;
    gap: 8px;
    font-weight: 700;
    font-size: 1rem;
    color: #1e3a8a;
}
body.dark .app-header-title { color: #93c5fd; }

.app-header-title svg {
    flex-shrink: 0;
    color: #2563eb;
}
body.dark .app-header-title svg { color: #60a5fa; }

.header-spacer { flex: 1; }

.header-btn {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    padding: 5px 10px;
    font-size: 0.8125rem;
    font-weight: 500;
    color: var(--btn-color);
    background: transparent;
    border: 1px solid var(--toolbar-border);
    border-radius: 6px;
    cursor: pointer;
    transition: background 0.12s, color 0.12s;
    text-decoration: none;
    white-space: nowrap;
}
.header-btn:hover { background: var(--btn-hover-bg); }
.header-btn svg   { flex-shrink: 0; }

/* ── Main 3-column layout (editor | splitter | preview) ─────────────────── */
.editor-main {
    display: flex;
    flex: 1;
    overflow: hidden;
    min-height: 0;
}

/* ── Editor pane ─────────────────────────────────────────────────────────── */
.editor-pane {
    display: flex;
    flex-direction: column;
    width: 50%;
    min-width: 220px;
    overflow: hidden;
    position: relative;     /* for drop overlay */
    background: var(--editor-bg);
}

.pane-toolbar {
    height: var(--editor-toolbar-h);
    background: var(--toolbar-bg);
    border-bottom: 1px solid var(--toolbar-border);
    display: flex;
    align-items: center;
    padding: 0 8px;
    gap: 4px;
    flex-shrink: 0;
    overflow-x: auto;
}

.pane-toolbar-label {
    font-size: 0.7rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.06em;
    color: var(--status-text);
    padding: 0 6px;
    flex-shrink: 0;
}

.tb-sep {
    width: 1px;
    height: 20px;
    background: var(--toolbar-border);
    margin: 0 4px;
    flex-shrink: 0;
}

.tb-btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 5px;
    padding: 4px 8px;
    font-size: 0.78rem;
    font-weight: 500;
    color: var(--btn-color);
    background: transparent;
    border: none;
    border-radius: 5px;
    cursor: pointer;
    white-space: nowrap;
    flex-shrink: 0;
    transition: background 0.1s, color 0.1s;
}
.tb-btn:hover  { background: var(--btn-hover-bg); }
.tb-btn.active { background: var(--btn-active-bg); color: var(--btn-active-color); }
.tb-btn svg    { flex-shrink: 0; }
.tb-btn:disabled {
    opacity: 0.5;
    cursor: default;
    pointer-events: none;
}

.tb-btn.btn-feedback-success { background: #d1fae5; color: #065f46; }
.tb-btn.btn-feedback-error   { background: #fee2e2; color: #b91c1c; }
body.dark .tb-btn.btn-feedback-success { background: #064e3b; color: #6ee7b7; }
body.dark .tb-btn.btn-feedback-error   { background: #450a0a; color: #fca5a5; }

.tb-toggle {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    padding: 4px 8px;
    border: 1px solid var(--toolbar-border);
    border-radius: 999px;
    color: var(--btn-color);
    font-size: 0.76rem;
    font-weight: 600;
    white-space: nowrap;
    flex-shrink: 0;
    cursor: pointer;
    user-select: none;
}

.tb-toggle:hover {
    background: var(--btn-hover-bg);
}

.tb-toggle input {
    margin: 0;
    accent-color: var(--color-primary);
}

/* Template select */
.tb-select {
    font-size: 0.78rem;
    color: var(--btn-color);
    background: transparent;
    border: 1px solid var(--toolbar-border);
    border-radius: 5px;
    padding: 3px 6px;
    cursor: pointer;
    max-width: 130px;
    flex-shrink: 0;
}
.tb-select:focus { outline: 2px solid var(--color-primary); outline-offset: 1px; }
body.dark .tb-select { background: var(--toolbar-bg); }

.editor-tabs-bar {
    height: var(--editor-tabs-h);
    background: var(--tab-bar-bg);
    border-bottom: 1px solid var(--toolbar-border);
    display: flex;
    align-items: flex-end;
    padding: 0 8px;
    flex-shrink: 0;
    min-height: 0;
}

.editor-tabs {
    flex: 1;
    min-width: 0;
    display: flex;
    align-items: flex-end;
    gap: 2px;
    overflow-x: auto;
    overflow-y: visible;
    scrollbar-width: none;
    padding: 0 2px;
}

.editor-tab {
    position: relative;
    min-width: 0;
    max-width: 220px;
    height: 33px;
    border: 1px solid var(--toolbar-border);
    border-bottom: none;
    border-radius: 8px 8px 0 0;
    background: var(--tab-inactive-bg);
    color: var(--status-text);
    display: inline-flex;
    align-items: center;
    gap: 4px;
    padding: 0 5px 0 8px;
    cursor: pointer;
    transition: background 0.12s, color 0.12s, border-color 0.12s;
    flex-shrink: 0;
    margin-bottom: -1px;
    z-index: 1;
    overflow: visible;
}

.editor-tab:hover {
    background: var(--toolbar-bg);
    color: var(--btn-color);
}

.editor-tab.active {
    background: var(--tab-active-bg);
    color: var(--tab-active-color);
    border-color: #93c5fd;
    z-index: 3;
}

/* Concave corner curves — Chrome-style connection to the editor area */
.editor-tab.active::before,
.editor-tab.active::after {
    content: '';
    position: absolute;
    bottom: 0;
    width: 8px;
    height: 8px;
    pointer-events: none;
}

.editor-tab.active::before {
    left: -8px;
    background: radial-gradient(circle at 100% 100%, transparent 8px, var(--tab-active-bg) 8px);
}

.editor-tab.active::after {
    right: -8px;
    background: radial-gradient(circle at 0% 100%, transparent 8px, var(--tab-active-bg) 8px);
}

.editor-tab-name {
    min-width: 0;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
    font-size: 0.76rem;
    font-weight: 600;
}

.editor-tab-rename-input {
    flex: 1 1 auto;
    min-width: 0;
    width: 100%;
    font: inherit;
    font-size: 0.76rem;
    font-weight: 600;
    color: inherit;
    background: rgba(255, 255, 255, 0.82);
    border: 1px solid rgba(37, 99, 235, 0.35);
    border-radius: 6px;
    padding: 4px 6px;
    outline: none;
}

.editor-tab-rename-input:focus {
    border-color: #2563eb;
    box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.16);
}

body.dark .editor-tab-rename-input {
    background: rgba(15, 23, 42, 0.9);
    border-color: rgba(96, 165, 250, 0.45);
}

.editor-tab-type {
    font-size: 0.66rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    color: var(--status-text);
    background: rgba(37, 99, 235, 0.12);
    padding: 1px 4px;
    border-radius: 999px;
    flex-shrink: 0;
}

.editor-tab.active .editor-tab-type {
    color: #1d4ed8;
}

body.dark .editor-tab-type {
    background: rgba(96, 165, 250, 0.14);
}

body.dark .editor-tab.active .editor-tab-type {
    color: #93c5fd;
}

body.dark .editor-tab.active {
    background: var(--tab-active-bg);
    color: var(--tab-active-color);
    border-color: #3b82f6;
}

.editor-tab-close,
.tab-add-btn {
    width: 20px;
    height: 20px;
    border-radius: 7px;
    border: 1px solid transparent;
    background: transparent;
    color: var(--status-text);
    display: inline-flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    flex-shrink: 0;
    transition: background 0.12s, color 0.12s, border-color 0.12s;
    align-self: center;
    margin-bottom: 1px;
}

.editor-tab-close:hover,
.tab-add-btn:hover {
    background: var(--btn-hover-bg);
    color: var(--btn-color);
}

.editor-tab-close:hover {
    border-color: var(--toolbar-border);
}

.tab-add-btn {
    width: 28px;
    height: 28px;
    border-color: var(--toolbar-border);
    color: var(--btn-color);
}

.tab-scroll-btn {
    width: 24px;
    height: 26px;
    border-radius: 5px;
    border: 1px solid var(--toolbar-border);
    background: var(--tab-bar-bg);
    color: var(--btn-color);
    display: inline-flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    flex-shrink: 0;
    transition: background 0.12s, color 0.12s;
    align-self: center;
}

.tab-scroll-btn:hover {
    background: var(--btn-hover-bg);
    color: var(--color-primary);
}

/* ── CodeMirror container ─────────────────────────────────────────────────── */
.editor-area {
    flex: 1;
    min-height: 0;
    overflow: hidden;
    position: relative;
}

.editor-area .CodeMirror {
    height: 100%;
    font-family: 'JetBrains Mono', 'Cascadia Code', 'Fira Code', 'Consolas', monospace;
    font-size: 13.5px;
    line-height: 1.6;
    background: var(--editor-bg);
    color: var(--color-text);
}

/* Mermaid syntax tokens */
.cm-s-default .cm-def       { color: #1d4ed8; font-weight: 700; } /* diagram type */
.cm-s-default .cm-keyword   { color: #7c3aed; font-weight: 600; }
.cm-s-default .cm-variable  { color: #374151; }
.cm-s-default .cm-string    { color: #059669; }
.cm-s-default .cm-bracket   { color: #b45309; }
.cm-s-default .cm-operator  { color: #d97706; font-weight: 600; }
.cm-s-default .cm-comment   { color: #9ca3af; font-style: italic; }
.cm-s-default .cm-number    { color: #db2777; }
.cm-s-default .cm-atom      { color: #0891b2; }

/* Dracula theme — Mermaid overrides */
.cm-s-dracula .cm-def       { color: #80bfff; font-weight: 700; }
.cm-s-dracula .cm-keyword   { color: #bd93f9; font-weight: 600; }
.cm-s-dracula .cm-string    { color: #50fa7b; }
.cm-s-dracula .cm-bracket   { color: #ffb86c; }
.cm-s-dracula .cm-operator  { color: #f1fa8c; font-weight: 600; }

/* Error highlighting */
.cm-error-line { background: rgba(220, 38, 38, 0.12) !important; }
.cm-error-text { text-decoration: wavy underline rgba(220, 38, 38, 0.8); }
body.dark .cm-error-line { background: rgba(248, 113, 113, 0.12) !important; }

/* ── Editor status bar ────────────────────────────────────────────────────── */
.editor-status {
    height: var(--editor-status-h);
    background: var(--status-bg);
    border-top: 1px solid var(--toolbar-border);
    display: flex;
    align-items: center;
    padding: 0 10px;
    gap: 12px;
    font-size: 0.72rem;
    color: var(--status-text);
    flex-shrink: 0;
    overflow: hidden;
}

.status-badge {
    background: #dbeafe;
    color: #1d4ed8;
    padding: 1px 6px;
    border-radius: 4px;
    font-weight: 600;
    font-size: 0.68rem;
    white-space: nowrap;
}
body.dark .status-badge { background: #1e3a5f; color: #93c5fd; }

.status-error {
    color: var(--error-text);
    font-size: 0.7rem;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
    flex: 1;
    /* button reset */
    background: none;
    border: none;
    padding: 0;
    margin: 0;
    text-align: left;
    font-family: inherit;
    cursor: pointer;
}
.status-error:hover { text-decoration: underline; }

/* ── Error detail popup ───────────────────────────────────────────────────── */
.status-error-popup {
    position: absolute;
    bottom: var(--editor-status-h);
    left: 0;
    right: 0;
    background: var(--error-bg);
    border-top: 1px solid var(--error-text);
    padding: 8px 10px 6px;
    z-index: 20;
    display: flex;
    flex-direction: column;
    gap: 6px;
    max-height: 180px;
    overflow: hidden;
}
.status-error-popup[hidden] { display: none; }

.status-error-popup-text {
    margin: 0;
    color: var(--error-text);
    font-family: ui-monospace, 'Cascadia Code', Consolas, monospace;
    font-size: 0.7rem;
    line-height: 1.5;
    white-space: pre-wrap;
    word-break: break-word;
    overflow-y: auto;
    max-height: 130px;
}

.status-error-popup-footer {
    display: flex;
    justify-content: flex-end;
    flex-shrink: 0;
}

.status-error-goto-btn {
    background: none;
    border: 1px solid var(--error-text);
    color: var(--error-text);
    border-radius: 4px;
    padding: 2px 8px;
    font-size: 0.68rem;
    font-family: inherit;
    cursor: pointer;
    line-height: 1.4;
}
.status-error-goto-btn:hover {
    background: var(--error-text);
    color: var(--error-bg);
}

/* ── Pane splitter ────────────────────────────────────────────────────────── */
.pane-splitter {
    width: var(--pane-splitter-w);
    background: var(--toolbar-border);
    cursor: col-resize;
    flex-shrink: 0;
    transition: background 0.15s;
    position: relative;
    z-index: 5;
}
.pane-splitter::after {
    content: '';
    position: absolute;
    left: -3px;
    right: -3px;
    top: 0;
    bottom: 0;
}
.pane-splitter:hover,
body.no-select .pane-splitter { background: var(--color-primary); }

/* ── Preview pane ─────────────────────────────────────────────────────────── */
.preview-pane {
    flex: 1;
    display: flex;
    flex-direction: column;
    min-width: 220px;
    overflow: hidden;
    position: relative;
    background: var(--preview-bg);
}

.preview-toolbar {
    height: var(--editor-toolbar-h);
    background: var(--toolbar-bg);
    border-bottom: 1px solid var(--toolbar-border);
    display: flex;
    align-items: center;
    padding: 0 8px;
    gap: 4px;
    flex-shrink: 0;
    overflow-x: auto;
}

/* Zoom display — clickable */
#zoom-display {
    font-size: 0.78rem;
    font-weight: 600;
    font-family: inherit;
    color: var(--btn-color);
    min-width: 44px;
    text-align: center;
    cursor: pointer;
    padding: 3px 6px;
    border-radius: 4px;
    border: 1px solid var(--toolbar-border);
    background: transparent;
    user-select: none;
}
#zoom-display:hover { background: var(--btn-hover-bg); }

/* Save button */
.file-actions {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    margin-left: auto;
    flex-shrink: 0;
}

.save-btn-wrap {
    position: relative;
    flex-shrink: 0;
}
#btn-save {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    padding: 5px 10px;
    font-size: 0.8rem;
    font-weight: 600;
    color: var(--save-btn-color);
    background: var(--save-btn-bg);
    border: none;
    border-radius: 6px;
    cursor: pointer;
    transition: background 0.12s;
}
#btn-save:hover { background: var(--save-btn-hover); }

/* Save dropdown */
.save-dropdown {
    display: none;
    position: fixed;
    /* top / right set dynamically by JS via getBoundingClientRect() */
    min-width: 220px;
    background: var(--dropdown-bg);
    border: 1px solid var(--dropdown-border);
    border-radius: 8px;
    box-shadow: 0 8px 24px rgba(0,0,0,0.14);
    z-index: 100;
    overflow: hidden;
    animation: dropdownOpen 0.12s ease;
}
.save-dropdown.show { display: block; }

@keyframes dropdownOpen {
    from { opacity: 0; transform: translateY(-4px); }
    to   { opacity: 1; transform: translateY(0); }
}

.save-dropdown-group {
    padding: 4px 0;
}
.save-dropdown-group + .save-dropdown-group {
    border-top: 1px solid var(--dropdown-border);
}

.save-dropdown-label {
    font-size: 0.67rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.07em;
    color: var(--status-text);
    padding: 6px 12px 2px;
}

.save-dropdown-item {
    display: flex;
    align-items: center;
    gap: 8px;
    padding: 7px 12px;
    font-size: 0.8125rem;
    color: var(--btn-color);
    cursor: pointer;
    transition: background 0.1s;
    /* reset <button> browser defaults */
    width: 100%;
    background: none;
    border: none;
    border-radius: 0;
    text-align: left;
    font-family: inherit;
}
.save-dropdown-item:hover { background: var(--dropdown-hover); }
.save-dropdown-item svg   { flex-shrink: 0; opacity: 0.7; }
.save-dropdown-item .zoom-val {
    font-size: 0.72rem;
    color: var(--status-text);
    margin-left: auto;
}

/* Mermaid theme select */
.mmd-theme-wrap {
    display: flex;
    align-items: center;
    gap: 5px;
    font-size: 0.75rem;
    color: var(--status-text);
    flex-shrink: 0;
    margin-left: 4px;
}
.mmd-theme-select {
    font-size: 0.75rem;
    color: var(--btn-color);
    background: transparent;
    border: 1px solid var(--toolbar-border);
    border-radius: 5px;
    padding: 3px 5px;
    cursor: pointer;
}
body.dark .mmd-theme-select { background: var(--toolbar-bg); }

.mmd-layout-wrap {
    display: flex;
    align-items: center;
    gap: 5px;
    font-size: 0.75rem;
    color: var(--status-text);
    flex-shrink: 0;
}

.mmd-layout-select,
.layout-option-select {
    font-size: 0.75rem;
    color: var(--btn-color);
    background: transparent;
    border: 1px solid var(--toolbar-border);
    border-radius: 5px;
    padding: 3px 5px;
    cursor: pointer;
}

body.dark .mmd-layout-select,
body.dark .layout-option-select {
    background: var(--toolbar-bg);
}

.layout-advanced {
    position: relative;
    flex-shrink: 0;
}

.layout-advanced summary {
    list-style: none;
    font-size: 0.75rem;
    color: var(--btn-color);
    border: 1px solid var(--toolbar-border);
    border-radius: 6px;
    padding: 4px 8px;
    cursor: pointer;
    user-select: none;
    white-space: nowrap;
}

.layout-advanced summary::-webkit-details-marker {
    display: none;
}

.layout-advanced[open] summary,
.layout-advanced summary:hover {
    background: var(--btn-hover-bg);
}

.layout-advanced-panel {
    position: fixed;
    min-width: 220px;
    background: var(--dropdown-bg);
    border: 1px solid var(--dropdown-border);
    border-radius: 8px;
    box-shadow: 0 8px 24px rgba(0,0,0,0.14);
    padding: 10px 12px;
    display: grid;
    gap: 10px;
    z-index: 80;
    display: none;
    visibility: hidden;
}

.layout-advanced[open] .layout-advanced-panel {
    display: grid;
}

.layout-advanced[open] .layout-advanced-panel.is-positioned {
    visibility: visible;
}

.layout-option-row,
.layout-option-stack {
    display: grid;
    gap: 6px;
    font-size: 0.76rem;
    color: var(--btn-color);
}

.layout-option-row {
    grid-template-columns: 16px 1fr;
    align-items: center;
}

.layout-option-row input {
    margin: 0;
}

/* ── Preview area ────────────────────────────────────────────────────────── */
.preview-area {
    flex: 1;
    overflow: hidden;
    position: relative;
    cursor: grab;
    user-select: none;
    -webkit-user-select: none;
}

#diagram-wrapper {
    position: absolute;
    top: 0;
    left: 0;
}

/* Diagram hint (empty state) */
.diagram-hint {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    font-size: 0.875rem;
    color: var(--status-text);
    text-align: center;
    pointer-events: none;
    white-space: nowrap;
}

/* Render error display */
.render-error {
    background: var(--error-bg);
    border: 1px solid rgba(220, 38, 38, 0.25);
    border-radius: 8px;
    padding: 16px 20px;
    max-width: 480px;
    margin: 40px auto;
}
.render-error-title {
    font-weight: 700;
    color: var(--error-text);
    margin-bottom: 8px;
    font-size: 0.925rem;
}
.render-error-pre {
    font-family: 'Cascadia Code', 'Consolas', monospace;
    font-size: 0.8rem;
    color: var(--error-text);
    white-space: pre-wrap;
    overflow-wrap: anywhere;
    margin: 0;
    opacity: 0.85;
    max-height: 200px;
    overflow-y: auto;
}

/* ── Drop overlays ────────────────────────────────────────────────────────── */
.drop-overlay {
    position: absolute;
    inset: 0;
    background: var(--drop-overlay-bg);
    border: 2px dashed var(--drop-overlay-border);
    border-radius: 4px;
    display: none;
    align-items: center;
    justify-content: center;
    z-index: 50;
    pointer-events: none;
    font-size: 0.9rem;
    font-weight: 600;
    color: var(--drop-overlay-border);
    gap: 8px;
}
.drop-overlay.visible { display: flex; }

/* ── Body helpers ─────────────────────────────────────────────────────────── */
body.no-select * { user-select: none; -webkit-user-select: none; }

/* ── Scrollbar for CodeMirror ─────────────────────────────────────────────── */
.CodeMirror-scroll { overflow-y: scroll !important; }

/* ── Responsive: narrow screens ───────────────────────────────────────────── */
@media (max-width: 600px) {
    .editor-pane { width: 100% !important; flex: none; }
    .pane-splitter { display: none; }
    .preview-pane { display: none; }
}

/* ── Animations ───────────────────────────────────────────────────────────── */
#diagram-wrapper { transition: none; }

/* ── SVG link interaction ─────────────────────────────────────────────────── */
#diagram-wrapper svg a { pointer-events: auto; }

/* ── Utility classes ─────────────────────────────────────────────────────── */
.hidden { display: none !important; }

/* Visually hidden but accessible to screen readers */
.sr-only {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    white-space: nowrap;
    border: 0;
}