diff --git a/frontend/css/lab.css b/frontend/css/lab.css
index 635cbef..e745f01 100644
--- a/frontend/css/lab.css
+++ b/frontend/css/lab.css
@@ -1945,6 +1945,86 @@ canvas[data-draggable]:active { cursor: grabbing; }
 .ptbl-reaction-eq { font-size: .78rem; font-weight: 600; font-family: 'Courier New', monospace; }
 .ptbl-reaction-note { font-size: .68rem; color: rgba(255,255,255,0.3); font-style: italic; margin-top: 4px; }
 
+/* ═══════════════════════════════════════════════════════════
+   GEOMETRY PANEL — modern layout (collapsible)
+   ═══════════════════════════════════════════════════════════ */
+.geo-panel-modern {
+  width: 260px !important;
+  padding: 10px 10px !important;
+  gap: 6px !important;
+}
+.geo-panel-modern .geo-tool-btn {
+  font-size: .78rem;
+  padding: 6px 8px;
+}
+
+/* sticky quick-access bar */
+.geo-quick-bar {
+  display: grid;
+  grid-template-columns: 1fr 1fr;
+  gap: 4px;
+  padding: 6px;
+  margin-bottom: 8px;
+  background: rgba(155,93,229,0.08);
+  border: 1px solid rgba(155,93,229,0.25);
+  border-radius: 10px;
+  position: sticky;
+  top: 0;
+  z-index: 5;
+}
+.geo-quick-bar .geo-tool-btn {
+  padding: 6px 8px;
+  background: rgba(255,255,255,0.04);
+  border-color: rgba(255,255,255,0.12);
+  font-size: .78rem;
+}
+
+/* accordion */
+.geo-acc {
+  border: 1px solid var(--border);
+  border-radius: 9px;
+  margin-bottom: 5px;
+  background: rgba(255,255,255,0.02);
+  overflow: hidden;
+}
+.geo-acc > summary {
+  cursor: pointer;
+  list-style: none;
+  padding: 7px 11px 7px 27px;
+  font-family: 'Unbounded', sans-serif;
+  font-size: .72rem;
+  font-weight: 700;
+  color: var(--text);
+  letter-spacing: .04em;
+  text-transform: uppercase;
+  position: relative;
+  user-select: none;
+  transition: background .15s;
+}
+.geo-acc > summary:hover { background: rgba(255,255,255,0.04); }
+.geo-acc > summary::-webkit-details-marker { display: none; }
+.geo-acc > summary::before {
+  content: '';
+  position: absolute;
+  left: 11px;
+  top: 50%;
+  width: 0;
+  height: 0;
+  border-left: 4.5px solid currentColor;
+  border-top: 3.5px solid transparent;
+  border-bottom: 3.5px solid transparent;
+  transform: translateY(-50%);
+  transition: transform .18s;
+  opacity: .6;
+}
+.geo-acc[open] > summary::before {
+  transform: translateY(-50%) rotate(90deg);
+}
+.geo-acc-body {
+  padding: 8px 10px 10px;
+  border-top: 1px solid var(--border);
+}
+
 /* ═══════════════════════════════════════════════════════════
    DYNAMICS PANEL — modern layout
    ═══════════════════════════════════════════════════════════ */
diff --git a/frontend/lab.html b/frontend/lab.html
index b73bcc6..fc30dd7 100644
--- a/frontend/lab.html
+++ b/frontend/lab.html
@@ -4252,11 +4252,10 @@
         <div class="sim-body-wrap">
 
           <!-- left panel -->
-          <div class="geo-panel">
+          <div class="geo-panel geo-panel-modern">
 
-            <!-- Tool: select + point -->
-            <div class="gp-section-title">Инструмент</div>
-            <div class="geo-tool-grid">
+            <!-- Quick-access bar: most-used tools always visible -->
+            <div class="geo-quick-bar">
               <button id="geo-btn-select" class="geo-tool-btn active" onclick="geoSetTool('select',this)" title="Выделить / переместить (Esc)">
                 <svg viewBox="0 0 24 24" fill="none"><path d="M5 3l14 9-7 1-4 7z" stroke-width="2"/></svg>
                 Выбор
@@ -4265,226 +4264,225 @@
                 <svg viewBox="0 0 24 24" fill="none"><circle cx="12" cy="12" r="4" fill="currentColor"/></svg>
                 Точка
               </button>
-            </div>
-
-            <div class="gp-section-title" style="margin-top:4px">Построения</div>
-            <div class="geo-tool-grid">
               <button id="geo-btn-segment" class="geo-tool-btn" onclick="geoSetTool('segment',this)" title="Отрезок — 2 точки">
                 <svg viewBox="0 0 24 24" fill="none"><line x1="4" y1="20" x2="20" y2="4" stroke-width="2.5"/><circle cx="4" cy="20" r="2.5" fill="currentColor"/><circle cx="20" cy="4" r="2.5" fill="currentColor"/></svg>
                 Отрезок
               </button>
-              <button id="geo-btn-line" class="geo-tool-btn" onclick="geoSetTool('line',this)" title="Прямая — 2 точки">
-                <svg viewBox="0 0 24 24" fill="none"><line x1="2" y1="22" x2="22" y2="2" stroke-width="2" stroke-dasharray="3,2"/></svg>
-                Прямая
-              </button>
-              <button id="geo-btn-ray" class="geo-tool-btn" onclick="geoSetTool('ray',this)" title="Луч — начало + направление">
-                <svg viewBox="0 0 24 24" fill="none"><line x1="4" y1="20" x2="22" y2="4" stroke-width="2"/><polyline points="17 4 22 4 22 9" stroke-width="2"/><circle cx="4" cy="20" r="2.5" fill="currentColor"/></svg>
-                Луч
-              </button>
               <button id="geo-btn-circle" class="geo-tool-btn" onclick="geoSetTool('circle',this)" title="Окружность — центр + радиус">
                 <svg viewBox="0 0 24 24" fill="none"><circle cx="12" cy="12" r="8" stroke-width="2"/><circle cx="12" cy="12" r="2" fill="currentColor"/></svg>
                 Круг
               </button>
             </div>
 
-            <div class="gp-section-title" style="margin-top:4px">Фигуры</div>
-            <div class="geo-tool-grid">
-              <button id="geo-btn-triangle" class="geo-tool-btn" onclick="geoSetTool('triangle',this)" title="Треугольник — 3 точки">
-                <svg viewBox="0 0 24 24" fill="none"><polygon points="12,3 22,21 2,21" stroke-width="2"/></svg>
-                Треуг.
-              </button>
-              <button id="geo-btn-quad" class="geo-tool-btn" onclick="geoSetTool('quad',this)" title="Четырёхугольник — 4 точки">
-                <svg viewBox="0 0 24 24" fill="none"><polygon points="3,6 21,4 20,19 4,20" stroke-width="2"/></svg>
-                Четырёх.
-              </button>
-              <button id="geo-btn-polygon" class="geo-tool-btn geo-tool-wide" onclick="geoSetTool('polygon',this)" title="Многоугольник — N точек, Enter/двойной клик для завершения">
-                <svg viewBox="0 0 24 24" fill="none"><polygon points="12,2 22,8 19,21 5,21 2,8" stroke-width="2"/></svg>
-                Многоугольник
-              </button>
-            </div>
-
-            <div class="gp-section-title" style="margin-top:4px">Построения</div>
-            <div class="geo-tool-grid">
-              <button id="geo-btn-midpoint" class="geo-tool-btn" onclick="geoSetTool('midpoint',this)" title="Середина отрезка — 2 точки">
-                <svg viewBox="0 0 24 24" fill="none"><line x1="3" y1="12" x2="21" y2="12" stroke-width="2"/><circle cx="12" cy="12" r="3.5" fill="currentColor"/></svg>
-                Середина
-              </button>
-              <button id="geo-btn-perpbisect" class="geo-tool-btn" onclick="geoSetTool('perpbisect',this)" title="Серединный перпендикуляр — 2 точки">
-                <svg viewBox="0 0 24 24" fill="none"><line x1="4" y1="18" x2="20" y2="6" stroke-width="2"/><line x1="12" y1="2" x2="12" y2="22" stroke-width="1.5" stroke-dasharray="3,2"/><circle cx="12" cy="12" r="2.5" fill="currentColor"/></svg>
-                ⊥ биссект.
-              </button>
-              <button id="geo-btn-anglebisect" class="geo-tool-btn" onclick="geoSetTool('anglebisect',this)" title="Биссектриса угла — 3 точки: A, вершина, B">
-                <svg viewBox="0 0 24 24" fill="none"><polyline points="4,20 12,4 20,20" stroke-width="2"/><line x1="12" y1="4" x2="12" y2="20" stroke-width="1.5" stroke-dasharray="3,2"/></svg>
-                ∠ биссект.
-              </button>
-              <button id="geo-btn-parallel" class="geo-tool-btn" onclick="geoSetTool('parallel',this)" title="Параллельная прямая — клик на линию, затем на точку">
-                <svg viewBox="0 0 24 24" fill="none"><line x1="3" y1="8" x2="21" y2="8" stroke-width="2"/><line x1="3" y1="16" x2="21" y2="16" stroke-width="2" opacity=".5" stroke-dasharray="4,3"/></svg>
-                || прямая
-              </button>
-              <button id="geo-btn-perpendicular" class="geo-tool-btn" onclick="geoSetTool('perpendicular',this)" title="Перпендикулярная прямая — клик на линию, затем на точку">
-                <svg viewBox="0 0 24 24" fill="none"><line x1="3" y1="12" x2="21" y2="12" stroke-width="2"/><line x1="12" y1="4" x2="12" y2="20" stroke-width="2" opacity=".5" stroke-dasharray="4,3"/></svg>
-                ⊥ прямая
-              </button>
-              <button id="geo-btn-intersect" class="geo-tool-btn" onclick="geoSetTool('intersect',this)" title="Точка пересечения — клик на две прямые">
-                <svg viewBox="0 0 24 24" fill="none"><line x1="4" y1="20" x2="20" y2="4" stroke-width="2"/><line x1="4" y1="4" x2="20" y2="20" stroke-width="2"/><circle cx="12" cy="12" r="3.5" fill="currentColor"/></svg>
-                Пересеч.
-              </button>
-              <button id="geo-btn-foot" class="geo-tool-btn" onclick="geoSetTool('foot',this)" title="Основание перпендикуляра — клик на прямую, затем на точку">
-                <svg viewBox="0 0 24 24" fill="none"><line x1="3" y1="18" x2="21" y2="18" stroke-width="2"/><line x1="12" y1="18" x2="12" y2="4" stroke-width="1.5" stroke-dasharray="3,2"/><path d="M12 18 L15 18 L15 15" stroke-width="1.5" fill="none"/><circle cx="12" cy="4" r="2.5" fill="currentColor"/></svg>
-                Основание
-              </button>
-              <button id="geo-btn-circumcircle" class="geo-tool-btn geo-tool-wide" onclick="geoSetTool('circumcircle',this)" title="Описанная окружность — 3 точки треугольника">
-                <svg viewBox="0 0 24 24" fill="none"><circle cx="12" cy="12" r="9" stroke-width="1.5" stroke-dasharray="4,3"/><polygon points="6,18 18,18 12,6" stroke-width="1.5" fill="none"/></svg>
-                Описанная
-              </button>
-              <button id="geo-btn-incircle" class="geo-tool-btn geo-tool-wide" onclick="geoSetTool('incircle',this)" title="Вписанная окружность — 3 точки треугольника">
-                <svg viewBox="0 0 24 24" fill="none"><polygon points="4,20 20,20 12,4" stroke-width="1.5" fill="none"/><circle cx="12" cy="15" r="5" stroke-width="1.5" stroke-dasharray="4,3"/></svg>
-                Вписанная
-              </button>
-            </div>
-
-            <div class="gp-section-title" style="margin-top:4px">Преобразования</div>
-            <div class="geo-tool-grid">
-              <button id="geo-btn-reflect" class="geo-tool-btn" onclick="geoSetTool('reflect',this)" title="Симметрия точки относительно прямой — клик на ось, затем на точку">
-                <svg viewBox="0 0 24 24" fill="none"><line x1="12" y1="2" x2="12" y2="22" stroke-width="1.5" stroke-dasharray="3,2"/><circle cx="6" cy="12" r="3" stroke-width="1.5"/><circle cx="18" cy="12" r="2.5" stroke-width="1.5" opacity=".5"/><line x1="9" y1="12" x2="15" y2="12" stroke-width="1" opacity=".6"/></svg>
-                Симметрия
-              </button>
-              <button id="geo-btn-translate" class="geo-tool-btn" onclick="geoSetTool('translate',this)" title="Параллельный перенос — вектор AB, затем точка P">
-                <svg viewBox="0 0 24 24" fill="none"><circle cx="6" cy="18" r="2.5" stroke-width="1.5"/><circle cx="18" cy="6" r="2.5" stroke-width="1.5"/><line x1="6" y1="18" x2="18" y2="6" stroke-width="1.5" marker-end="url(#arrow)"/><circle cx="14" cy="18" r="2.5" stroke-width="1.5" opacity=".4"/><circle cx="21" cy="9" r="2" stroke-width="1.5" stroke-dasharray="3,2"/></svg>
-                Перенос
-              </button>
-              <button id="geo-btn-tangent" class="geo-tool-btn geo-tool-wide" onclick="geoSetTool('tangent',this)" title="Касательные из точки к окружности — клик на окружность, затем на точку">
-                <svg viewBox="0 0 24 24" fill="none"><circle cx="12" cy="12" r="7" stroke-width="1.5"/><line x1="4" y1="4" x2="19" y2="12" stroke-width="1.5" stroke-dasharray="4,3"/><line x1="4" y1="20" x2="19" y2="12" stroke-width="1.5" stroke-dasharray="4,3"/><circle cx="4" cy="12" r="2.5" fill="currentColor"/></svg>
-                Касательные
-              </button>
-            </div>
-
-            <div class="gp-section-title" style="margin-top:4px">Элементы треугольника</div>
-            <div class="geo-tool-grid">
-              <button id="geo-btn-altitude" class="geo-tool-btn" onclick="geoSetTool('altitude',this)" title="Высота — клик на сторону, затем на вершину">
-                <svg viewBox="0 0 24 24" fill="none"><line x1="3" y1="20" x2="21" y2="20" stroke-width="1.5"/><line x1="10" y1="4" x2="10" y2="20" stroke-width="1.5" stroke-dasharray="4,3"/><rect x="10" y="14" width="4" height="4" stroke-width="1.2"/><polygon points="10,4 3,20 21,20" stroke-width="1.5" fill="none"/></svg>
-                Высота
-              </button>
-              <button id="geo-btn-median" class="geo-tool-btn" onclick="geoSetTool('median',this)" title="Медиана — клик вершина A, B, C">
-                <svg viewBox="0 0 24 24" fill="none"><polygon points="12,3 3,20 21,20" stroke-width="1.5" fill="none"/><line x1="12" y1="3" x2="12" y2="20" stroke-width="1.5"/><circle cx="12" cy="20" r="2.5" fill="currentColor"/></svg>
-                Медиана
-              </button>
-              <button id="geo-btn-centroid" class="geo-tool-btn" onclick="geoSetTool('centroid',this)" title="Центроид — 3 точки треугольника, строит 3 медианы">
-                <svg viewBox="0 0 24 24" fill="none"><polygon points="12,3 3,20 21,20" stroke-width="1.5" fill="none"/><line x1="12" y1="3" x2="12" y2="20" stroke-width="1.2" opacity=".6"/><line x1="3" y1="20" x2="16.5" y2="11.5" stroke-width="1.2" opacity=".6"/><line x1="21" y1="20" x2="7.5" y2="11.5" stroke-width="1.2" opacity=".6"/><circle cx="12" cy="14.3" r="2.5" fill="currentColor"/></svg>
-                Центроид
-              </button>
-              <button id="geo-btn-orthocenter" class="geo-tool-btn" onclick="geoSetTool('orthocenter',this)" title="Ортоцентр — 3 точки треугольника, строит 3 высоты">
-                <svg viewBox="0 0 24 24" fill="none"><polygon points="12,3 3,20 21,20" stroke-width="1.5" fill="none"/><line x1="12" y1="3" x2="12" y2="20" stroke-width="1.2" stroke-dasharray="3,2" opacity=".6"/><line x1="3" y1="20" x2="16" y2="12" stroke-width="1.2" stroke-dasharray="3,2" opacity=".6"/><line x1="21" y1="20" x2="8" y2="12" stroke-width="1.2" stroke-dasharray="3,2" opacity=".6"/><circle cx="12" cy="14" r="2.5" fill="currentColor"/></svg>
-                Ортоцентр
-              </button>
-            </div>
-
-            <div class="gp-section-title" style="margin-top:4px">Средняя линия и четырёхугольники</div>
-            <div class="geo-tool-grid">
-              <button id="geo-btn-midline" class="geo-tool-btn" onclick="geoSetTool('midline',this)" title="Средняя линия треугольника — 3 вершины A, B, C">
-                <svg viewBox="0 0 24 24" fill="none"><polygon points="12,3 3,20 21,20" stroke-width="1.5" fill="none"/><line x1="7.5" y1="11.5" x2="16.5" y2="11.5" stroke-width="2"/><circle cx="7.5" cy="11.5" r="2" fill="currentColor"/><circle cx="16.5" cy="11.5" r="2" fill="currentColor"/></svg>
-                Средняя линия
-              </button>
-              <button id="geo-btn-parallelogram" class="geo-tool-btn" onclick="geoSetTool('parallelogram',this)" title="Параллелограмм — 3 точки A, B, C → вычисляет D">
-                <svg viewBox="0 0 24 24" fill="none"><polygon points="6,19 3,5 18,5 21,19" stroke-width="1.5" fill="none"/></svg>
-                Параллелограмм
-              </button>
-              <button id="geo-btn-diagonal" class="geo-tool-btn" onclick="geoSetTool('diagonal',this)" title="Диагонали — клик внутри многоугольника (4+ вершин)">
-                <svg viewBox="0 0 24 24" fill="none"><rect x="3" y="3" width="18" height="18" stroke-width="1.5" fill="none"/><line x1="3" y1="3" x2="21" y2="21" stroke-width="1.5" stroke-dasharray="4,2"/><line x1="21" y1="3" x2="3" y2="21" stroke-width="1.5" stroke-dasharray="4,2"/></svg>
-                Диагонали
-              </button>
-              <button id="geo-btn-scale" class="geo-tool-btn" onclick="geoSetTool('scale',this)" title="Подобие — клик центр O, затем клик точку P → P&#39; = O + k·(P − O)">
-                <svg viewBox="0 0 24 24" fill="none"><circle cx="12" cy="12" r="2" fill="currentColor"/><line x1="12" y1="12" x2="20" y2="6" stroke-width="1.5"/><circle cx="20" cy="6" r="2.5" stroke-width="1.5"/><line x1="12" y1="12" x2="17" y2="18" stroke-width="1.5" stroke-dasharray="3,2"/><circle cx="17" cy="18" r="2.5" stroke-width="1.5" stroke-dasharray="3,2"/></svg>
-                Подобие
-              </button>
-            </div>
-            <div class="geo-ngon-ctrl" id="geo-scale-ctrl" style="gap:6px;padding:2px 0 4px">
-              <span style="font-size:11px;opacity:.7">k =</span>
-              <button class="geo-ngon-btn" onclick="geoScaleK(-0.5)">
-                <svg viewBox="0 0 16 16" fill="none"><line x1="3" y1="8" x2="13" y2="8" stroke-width="2" stroke-linecap="round"/></svg>
-              </button>
-              <span id="geo-scale-k">2</span>
-              <button class="geo-ngon-btn" onclick="geoScaleK(+0.5)">
-                <svg viewBox="0 0 16 16" fill="none"><line x1="8" y1="3" x2="8" y2="13" stroke-width="2" stroke-linecap="round"/><line x1="3" y1="8" x2="13" y2="8" stroke-width="2" stroke-linecap="round"/></svg>
-              </button>
-            </div>
-
-            <div class="gp-section-title" style="margin-top:4px">Правильный многоугольник</div>
-            <div class="geo-tool-grid">
-              <button id="geo-btn-ngon" class="geo-tool-btn" onclick="geoSetTool('ngon',this)" title="Правильный n-угольник — клик центр, клик вершина">
-                <svg viewBox="0 0 24 24" fill="none"><polygon points="12,3 20.2,8.5 17.3,18 6.7,18 3.8,8.5" stroke-width="1.5" fill="none"/></svg>
-                n-угольник
-              </button>
-              <div class="geo-ngon-ctrl" id="geo-ngon-ctrl">
-                <button class="geo-ngon-btn" onclick="geoNgonN(-1)">
-                  <svg viewBox="0 0 16 16" fill="none"><line x1="3" y1="8" x2="13" y2="8" stroke-width="2" stroke-linecap="round"/></svg>
+            <details class="geo-acc">
+              <summary>Линии</summary>
+              <div class="geo-acc-body geo-tool-grid">
+                <button id="geo-btn-line" class="geo-tool-btn" onclick="geoSetTool('line',this)" title="Прямая — 2 точки">
+                  <svg viewBox="0 0 24 24" fill="none"><line x1="2" y1="22" x2="22" y2="2" stroke-width="2" stroke-dasharray="3,2"/></svg>
+                  Прямая
                 </button>
-                <span id="geo-ngon-n">6</span>
-                <button class="geo-ngon-btn" onclick="geoNgonN(+1)">
-                  <svg viewBox="0 0 16 16" fill="none"><line x1="8" y1="3" x2="8" y2="13" stroke-width="2" stroke-linecap="round"/><line x1="3" y1="8" x2="13" y2="8" stroke-width="2" stroke-linecap="round"/></svg>
+                <button id="geo-btn-ray" class="geo-tool-btn" onclick="geoSetTool('ray',this)" title="Луч — начало + направление">
+                  <svg viewBox="0 0 24 24" fill="none"><line x1="4" y1="20" x2="22" y2="4" stroke-width="2"/><polyline points="17 4 22 4 22 9" stroke-width="2"/><circle cx="4" cy="20" r="2.5" fill="currentColor"/></svg>
+                  Луч
                 </button>
               </div>
-            </div>
+            </details>
 
-            <!-- Thales theorem -->
-            <div class="gp-section-title" style="margin-top:4px">Теорема Фалеса</div>
-            <div class="geo-tool-grid">
-              <button id="geo-btn-thales" class="geo-tool-btn" onclick="geoSetTool('thales',this)" title="Теорема Фалеса — клик O, затем A, затем B → A&#39;B&#39; ∥ AB">
-                <svg viewBox="0 0 24 24" fill="none"><circle cx="4" cy="20" r="2" fill="currentColor"/><line x1="4" y1="20" x2="22" y2="4" stroke-width="1.5"/><line x1="4" y1="20" x2="22" y2="12" stroke-width="1.5"/><line x1="10" y1="15" x2="13" y2="12" stroke-width="2" stroke-dasharray="0"/><line x1="17" y1="9" x2="20" y2="7" stroke-width="2" opacity=".6"/></svg>
-                Фалес
-              </button>
-            </div>
+            <details class="geo-acc">
+              <summary>Фигуры</summary>
+              <div class="geo-acc-body">
+                <div class="geo-tool-grid">
+                  <button id="geo-btn-triangle" class="geo-tool-btn" onclick="geoSetTool('triangle',this)" title="Треугольник — 3 точки">
+                    <svg viewBox="0 0 24 24" fill="none"><polygon points="12,3 22,21 2,21" stroke-width="2"/></svg>
+                    Треуг.
+                  </button>
+                  <button id="geo-btn-quad" class="geo-tool-btn" onclick="geoSetTool('quad',this)" title="Четырёхугольник — 4 точки">
+                    <svg viewBox="0 0 24 24" fill="none"><polygon points="3,6 21,4 20,19 4,20" stroke-width="2"/></svg>
+                    Четырёх.
+                  </button>
+                  <button id="geo-btn-polygon" class="geo-tool-btn geo-tool-wide" onclick="geoSetTool('polygon',this)" title="Многоугольник — N точек, Enter/двойной клик для завершения">
+                    <svg viewBox="0 0 24 24" fill="none"><polygon points="12,2 22,8 19,21 5,21 2,8" stroke-width="2"/></svg>
+                    Многоугольник
+                  </button>
+                  <button id="geo-btn-parallelogram" class="geo-tool-btn" onclick="geoSetTool('parallelogram',this)" title="Параллелограмм — 3 точки A, B, C → вычисляет D">
+                    <svg viewBox="0 0 24 24" fill="none"><polygon points="6,19 3,5 18,5 21,19" stroke-width="1.5" fill="none"/></svg>
+                    Парал-мм
+                  </button>
+                  <button id="geo-btn-ngon" class="geo-tool-btn" onclick="geoSetTool('ngon',this)" title="Правильный n-угольник — клик центр, клик вершина">
+                    <svg viewBox="0 0 24 24" fill="none"><polygon points="12,3 20.2,8.5 17.3,18 6.7,18 3.8,8.5" stroke-width="1.5" fill="none"/></svg>
+                    n-уг.
+                  </button>
+                </div>
+                <div class="geo-ngon-ctrl" id="geo-ngon-ctrl" style="margin-top:6px">
+                  <span style="font-size:11px;opacity:.7">N =</span>
+                  <button class="geo-ngon-btn" onclick="geoNgonN(-1)">
+                    <svg viewBox="0 0 16 16" fill="none"><line x1="3" y1="8" x2="13" y2="8" stroke-width="2" stroke-linecap="round"/></svg>
+                  </button>
+                  <span id="geo-ngon-n">6</span>
+                  <button class="geo-ngon-btn" onclick="geoNgonN(+1)">
+                    <svg viewBox="0 0 16 16" fill="none"><line x1="8" y1="3" x2="8" y2="13" stroke-width="2" stroke-linecap="round"/><line x1="3" y1="8" x2="13" y2="8" stroke-width="2" stroke-linecap="round"/></svg>
+                  </button>
+                </div>
+              </div>
+            </details>
 
-            <!-- Mark tools -->
-            <div class="gp-section-title" style="margin-top:4px">Метки</div>
-            <div class="geo-tool-grid">
-              <button id="geo-btn-tick" class="geo-tool-btn" onclick="geoSetTool('tick',this)" title="Метки равных сторон — клик на отрезок или сторону (1–3 штриха)">
-                <svg viewBox="0 0 24 24" fill="none"><line x1="3" y1="20" x2="21" y2="4" stroke-width="1.5"/><line x1="11" y1="7" x2="8" y2="11" stroke-width="2" stroke-linecap="round"/><line x1="13" y1="9" x2="10" y2="13" stroke-width="2" stroke-linecap="round"/></svg>
-                Штрихи
-              </button>
-              <button id="geo-btn-arcmark" class="geo-tool-btn" onclick="geoSetTool('arcmark',this)" title="Метки равных углов — клик на вершину полигона (1–3 дуги)">
-                <svg viewBox="0 0 24 24" fill="none"><path d="M4 20 L20 20 L20 4" stroke-width="1.5" fill="none"/><path d="M8 20 A12 12 0 0 1 20 8" stroke-width="1.5" fill="none"/><path d="M11 20 A9 9 0 0 1 20 11" stroke-width="1.5" fill="none"/></svg>
-                Дуги
-              </button>
-              <button id="geo-btn-parallelmark" class="geo-tool-btn" onclick="geoSetTool('parallelmark',this)" title="Метки параллельных сторон — клик на отрезок (1–2 стрелки)">
-                <svg viewBox="0 0 24 24" fill="none"><line x1="3" y1="8" x2="21" y2="8" stroke-width="1.5"/><polyline points="9,5 13,8 9,11" stroke-width="1.8" fill="none" stroke-linecap="round" stroke-linejoin="round"/><line x1="3" y1="16" x2="21" y2="16" stroke-width="1.5"/><polyline points="9,13 13,16 9,19" stroke-width="1.8" fill="none" stroke-linecap="round" stroke-linejoin="round"/></svg>
-                Параллельность
-              </button>
-            </div>
+            <details class="geo-acc">
+              <summary>Построения</summary>
+              <div class="geo-acc-body geo-tool-grid">
+                <button id="geo-btn-midpoint" class="geo-tool-btn" onclick="geoSetTool('midpoint',this)" title="Середина отрезка — 2 точки">
+                  <svg viewBox="0 0 24 24" fill="none"><line x1="3" y1="12" x2="21" y2="12" stroke-width="2"/><circle cx="12" cy="12" r="3.5" fill="currentColor"/></svg>
+                  Середина
+                </button>
+                <button id="geo-btn-intersect" class="geo-tool-btn" onclick="geoSetTool('intersect',this)" title="Точка пересечения — клик на две прямые">
+                  <svg viewBox="0 0 24 24" fill="none"><line x1="4" y1="20" x2="20" y2="4" stroke-width="2"/><line x1="4" y1="4" x2="20" y2="20" stroke-width="2"/><circle cx="12" cy="12" r="3.5" fill="currentColor"/></svg>
+                  Пересеч.
+                </button>
+                <button id="geo-btn-perpbisect" class="geo-tool-btn" onclick="geoSetTool('perpbisect',this)" title="Серединный перпендикуляр — 2 точки">
+                  <svg viewBox="0 0 24 24" fill="none"><line x1="4" y1="18" x2="20" y2="6" stroke-width="2"/><line x1="12" y1="2" x2="12" y2="22" stroke-width="1.5" stroke-dasharray="3,2"/><circle cx="12" cy="12" r="2.5" fill="currentColor"/></svg>
+                  ⊥ биссект.
+                </button>
+                <button id="geo-btn-anglebisect" class="geo-tool-btn" onclick="geoSetTool('anglebisect',this)" title="Биссектриса угла — 3 точки: A, вершина, B">
+                  <svg viewBox="0 0 24 24" fill="none"><polyline points="4,20 12,4 20,20" stroke-width="2"/><line x1="12" y1="4" x2="12" y2="20" stroke-width="1.5" stroke-dasharray="3,2"/></svg>
+                  ∠ биссект.
+                </button>
+                <button id="geo-btn-parallel" class="geo-tool-btn" onclick="geoSetTool('parallel',this)" title="Параллельная прямая — клик на линию, затем на точку">
+                  <svg viewBox="0 0 24 24" fill="none"><line x1="3" y1="8" x2="21" y2="8" stroke-width="2"/><line x1="3" y1="16" x2="21" y2="16" stroke-width="2" opacity=".5" stroke-dasharray="4,3"/></svg>
+                  ∥ прямая
+                </button>
+                <button id="geo-btn-perpendicular" class="geo-tool-btn" onclick="geoSetTool('perpendicular',this)" title="Перпендикулярная прямая — клик на линию, затем на точку">
+                  <svg viewBox="0 0 24 24" fill="none"><line x1="3" y1="12" x2="21" y2="12" stroke-width="2"/><line x1="12" y1="4" x2="12" y2="20" stroke-width="2" opacity=".5" stroke-dasharray="4,3"/></svg>
+                  ⊥ прямая
+                </button>
+                <button id="geo-btn-foot" class="geo-tool-btn" onclick="geoSetTool('foot',this)" title="Основание перпендикуляра — клик на прямую, затем на точку">
+                  <svg viewBox="0 0 24 24" fill="none"><line x1="3" y1="18" x2="21" y2="18" stroke-width="2"/><line x1="12" y1="18" x2="12" y2="4" stroke-width="1.5" stroke-dasharray="3,2"/><path d="M12 18 L15 18 L15 15" stroke-width="1.5" fill="none"/><circle cx="12" cy="4" r="2.5" fill="currentColor"/></svg>
+                  Основание
+                </button>
+                <button id="geo-btn-tangent" class="geo-tool-btn" onclick="geoSetTool('tangent',this)" title="Касательные из точки к окружности — клик на окружность, затем на точку">
+                  <svg viewBox="0 0 24 24" fill="none"><circle cx="12" cy="12" r="7" stroke-width="1.5"/><line x1="4" y1="4" x2="19" y2="12" stroke-width="1.5" stroke-dasharray="4,3"/><line x1="4" y1="20" x2="19" y2="12" stroke-width="1.5" stroke-dasharray="4,3"/><circle cx="4" cy="12" r="2.5" fill="currentColor"/></svg>
+                  Касат.
+                </button>
+                <button id="geo-btn-diagonal" class="geo-tool-btn" onclick="geoSetTool('diagonal',this)" title="Диагонали — клик внутри многоугольника (4+ вершин)">
+                  <svg viewBox="0 0 24 24" fill="none"><rect x="3" y="3" width="18" height="18" stroke-width="1.5" fill="none"/><line x1="3" y1="3" x2="21" y2="21" stroke-width="1.5" stroke-dasharray="4,2"/><line x1="21" y1="3" x2="3" y2="21" stroke-width="1.5" stroke-dasharray="4,2"/></svg>
+                  Диагонали
+                </button>
+                <button id="geo-btn-circumcircle" class="geo-tool-btn geo-tool-wide" onclick="geoSetTool('circumcircle',this)" title="Описанная окружность — 3 точки треугольника">
+                  <svg viewBox="0 0 24 24" fill="none"><circle cx="12" cy="12" r="9" stroke-width="1.5" stroke-dasharray="4,3"/><polygon points="6,18 18,18 12,6" stroke-width="1.5" fill="none"/></svg>
+                  Описанная
+                </button>
+                <button id="geo-btn-incircle" class="geo-tool-btn geo-tool-wide" onclick="geoSetTool('incircle',this)" title="Вписанная окружность — 3 точки треугольника">
+                  <svg viewBox="0 0 24 24" fill="none"><polygon points="4,20 20,20 12,4" stroke-width="1.5" fill="none"/><circle cx="12" cy="15" r="5" stroke-width="1.5" stroke-dasharray="4,3"/></svg>
+                  Вписанная
+                </button>
+              </div>
+            </details>
 
-            <!-- Constrained points for locus -->
-            <div class="gp-section-title" style="margin-top:4px">Точки на объектах</div>
-            <div class="geo-tool-grid">
-              <button id="geo-btn-point_on_segment" class="geo-tool-btn" onclick="geoSetTool('point_on_segment',this)" title="Точка на отрезке — кликни на отрезок, получишь скользящую точку">
-                <svg class="ic" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round"><line x1="3" y1="20" x2="21" y2="4"/><circle cx="12" cy="12" r="3" fill="currentColor" stroke="none"/></svg>
-                На отрезке
-              </button>
-              <button id="geo-btn-point_on_circle" class="geo-tool-btn" onclick="geoSetTool('point_on_circle',this)" title="Точка на окружности — кликни на окружность, получишь скользящую точку">
-                <svg class="ic" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round"><circle cx="12" cy="12" r="9"/><circle cx="12" cy="3" r="2.5" fill="currentColor" stroke="none"/></svg>
-                На окружности
-              </button>
-            </div>
+            <details class="geo-acc">
+              <summary>Треугольник</summary>
+              <div class="geo-acc-body geo-tool-grid">
+                <button id="geo-btn-altitude" class="geo-tool-btn" onclick="geoSetTool('altitude',this)" title="Высота — клик на сторону, затем на вершину">
+                  <svg viewBox="0 0 24 24" fill="none"><line x1="3" y1="20" x2="21" y2="20" stroke-width="1.5"/><line x1="10" y1="4" x2="10" y2="20" stroke-width="1.5" stroke-dasharray="4,3"/><rect x="10" y="14" width="4" height="4" stroke-width="1.2"/><polygon points="10,4 3,20 21,20" stroke-width="1.5" fill="none"/></svg>
+                  Высота
+                </button>
+                <button id="geo-btn-median" class="geo-tool-btn" onclick="geoSetTool('median',this)" title="Медиана — клик вершина A, B, C">
+                  <svg viewBox="0 0 24 24" fill="none"><polygon points="12,3 3,20 21,20" stroke-width="1.5" fill="none"/><line x1="12" y1="3" x2="12" y2="20" stroke-width="1.5"/><circle cx="12" cy="20" r="2.5" fill="currentColor"/></svg>
+                  Медиана
+                </button>
+                <button id="geo-btn-centroid" class="geo-tool-btn" onclick="geoSetTool('centroid',this)" title="Центроид — 3 точки треугольника, строит 3 медианы">
+                  <svg viewBox="0 0 24 24" fill="none"><polygon points="12,3 3,20 21,20" stroke-width="1.5" fill="none"/><line x1="12" y1="3" x2="12" y2="20" stroke-width="1.2" opacity=".6"/><line x1="3" y1="20" x2="16.5" y2="11.5" stroke-width="1.2" opacity=".6"/><line x1="21" y1="20" x2="7.5" y2="11.5" stroke-width="1.2" opacity=".6"/><circle cx="12" cy="14.3" r="2.5" fill="currentColor"/></svg>
+                  Центроид
+                </button>
+                <button id="geo-btn-orthocenter" class="geo-tool-btn" onclick="geoSetTool('orthocenter',this)" title="Ортоцентр — 3 точки треугольника, строит 3 высоты">
+                  <svg viewBox="0 0 24 24" fill="none"><polygon points="12,3 3,20 21,20" stroke-width="1.5" fill="none"/><line x1="12" y1="3" x2="12" y2="20" stroke-width="1.2" stroke-dasharray="3,2" opacity=".6"/><line x1="3" y1="20" x2="16" y2="12" stroke-width="1.2" stroke-dasharray="3,2" opacity=".6"/><line x1="21" y1="20" x2="8" y2="12" stroke-width="1.2" stroke-dasharray="3,2" opacity=".6"/><circle cx="12" cy="14" r="2.5" fill="currentColor"/></svg>
+                  Ортоцентр
+                </button>
+                <button id="geo-btn-midline" class="geo-tool-btn geo-tool-wide" onclick="geoSetTool('midline',this)" title="Средняя линия треугольника — 3 вершины A, B, C">
+                  <svg viewBox="0 0 24 24" fill="none"><polygon points="12,3 3,20 21,20" stroke-width="1.5" fill="none"/><line x1="7.5" y1="11.5" x2="16.5" y2="11.5" stroke-width="2"/><circle cx="7.5" cy="11.5" r="2" fill="currentColor"/><circle cx="16.5" cy="11.5" r="2" fill="currentColor"/></svg>
+                  Средняя линия
+                </button>
+                <button id="geo-btn-thales" class="geo-tool-btn geo-tool-wide" onclick="geoSetTool('thales',this)" title="Теорема Фалеса — клик O, затем A, затем B → A&#39;B&#39; ∥ AB">
+                  <svg viewBox="0 0 24 24" fill="none"><circle cx="4" cy="20" r="2" fill="currentColor"/><line x1="4" y1="20" x2="22" y2="4" stroke-width="1.5"/><line x1="4" y1="20" x2="22" y2="12" stroke-width="1.5"/><line x1="10" y1="15" x2="13" y2="12" stroke-width="2" stroke-dasharray="0"/><line x1="17" y1="9" x2="20" y2="7" stroke-width="2" opacity=".6"/></svg>
+                  Фалес
+                </button>
+              </div>
+            </details>
 
-            <!-- Measurement + Locus tools -->
-            <div class="gp-section-title" style="margin-top:4px">Измерения и ГМТ</div>
-            <div class="geo-tool-grid">
-              <button id="geo-btn-measure_length" class="geo-tool-btn" onclick="geoSetTool('measure_length',this)" title="Длина отрезка — кликни на отрезок, получишь живой чип">
-                <svg viewBox="0 0 24 24" fill="none"><line x1="3" y1="12" x2="21" y2="12" stroke-width="2"/><line x1="3" y1="8" x2="3" y2="16" stroke-width="2" stroke-linecap="round"/><line x1="21" y1="8" x2="21" y2="16" stroke-width="2" stroke-linecap="round"/></svg>
-                Длина
-              </button>
-              <button id="geo-btn-measure_angle" class="geo-tool-btn" onclick="geoSetTool('measure_angle',this)" title="Угол — 3 клика: точка A, вершина, точка B">
-                <svg viewBox="0 0 24 24" fill="none"><path d="M3 20 L20 20" stroke-width="2" stroke-linecap="round"/><path d="M3 20 L14 6" stroke-width="2" stroke-linecap="round"/><path d="M7 20 A10 10 0 0 1 11.5 12" stroke-width="1.5" fill="none"/></svg>
-                Угол
-              </button>
-              <button id="geo-btn-measure_area" class="geo-tool-btn" onclick="geoSetTool('measure_area',this)" title="Площадь многоугольника — кликни на полигон">
-                <svg viewBox="0 0 24 24" fill="none"><polygon points="12,3 21,9 18,20 6,20 3,9" stroke-width="2" fill="none"/></svg>
-                Площадь
-              </button>
-              <button id="geo-btn-locus" class="geo-tool-btn" onclick="geoSetTool('locus',this)" title="ГМТ — выбери точку-мовер (on_segment/on_circle), затем целевую точку">
-                <svg viewBox="0 0 24 24" fill="none"><path d="M4 20 Q8 4 12 12 Q16 20 20 6" stroke-width="2" fill="none" stroke-linecap="round" stroke-linejoin="round"/><circle cx="8" cy="14" r="2" fill="currentColor"/></svg>
-                ГМТ
-              </button>
-            </div>
+            <details class="geo-acc">
+              <summary>Преобразования</summary>
+              <div class="geo-acc-body">
+                <div class="geo-tool-grid">
+                  <button id="geo-btn-reflect" class="geo-tool-btn" onclick="geoSetTool('reflect',this)" title="Симметрия точки относительно прямой — клик на ось, затем на точку">
+                    <svg viewBox="0 0 24 24" fill="none"><line x1="12" y1="2" x2="12" y2="22" stroke-width="1.5" stroke-dasharray="3,2"/><circle cx="6" cy="12" r="3" stroke-width="1.5"/><circle cx="18" cy="12" r="2.5" stroke-width="1.5" opacity=".5"/><line x1="9" y1="12" x2="15" y2="12" stroke-width="1" opacity=".6"/></svg>
+                    Симметрия
+                  </button>
+                  <button id="geo-btn-translate" class="geo-tool-btn" onclick="geoSetTool('translate',this)" title="Параллельный перенос — вектор AB, затем точка P">
+                    <svg viewBox="0 0 24 24" fill="none"><circle cx="6" cy="18" r="2.5" stroke-width="1.5"/><circle cx="18" cy="6" r="2.5" stroke-width="1.5"/><line x1="6" y1="18" x2="18" y2="6" stroke-width="1.5" marker-end="url(#arrow)"/><circle cx="14" cy="18" r="2.5" stroke-width="1.5" opacity=".4"/><circle cx="21" cy="9" r="2" stroke-width="1.5" stroke-dasharray="3,2"/></svg>
+                    Перенос
+                  </button>
+                  <button id="geo-btn-scale" class="geo-tool-btn geo-tool-wide" onclick="geoSetTool('scale',this)" title="Подобие — клик центр O, затем клик точку P → P&#39; = O + k·(P − O)">
+                    <svg viewBox="0 0 24 24" fill="none"><circle cx="12" cy="12" r="2" fill="currentColor"/><line x1="12" y1="12" x2="20" y2="6" stroke-width="1.5"/><circle cx="20" cy="6" r="2.5" stroke-width="1.5"/><line x1="12" y1="12" x2="17" y2="18" stroke-width="1.5" stroke-dasharray="3,2"/><circle cx="17" cy="18" r="2.5" stroke-width="1.5" stroke-dasharray="3,2"/></svg>
+                    Подобие (гомотетия)
+                  </button>
+                </div>
+                <div class="geo-ngon-ctrl" id="geo-scale-ctrl" style="margin-top:6px">
+                  <span style="font-size:11px;opacity:.7">k =</span>
+                  <button class="geo-ngon-btn" onclick="geoScaleK(-0.5)">
+                    <svg viewBox="0 0 16 16" fill="none"><line x1="3" y1="8" x2="13" y2="8" stroke-width="2" stroke-linecap="round"/></svg>
+                  </button>
+                  <span id="geo-scale-k">2</span>
+                  <button class="geo-ngon-btn" onclick="geoScaleK(+0.5)">
+                    <svg viewBox="0 0 16 16" fill="none"><line x1="8" y1="3" x2="8" y2="13" stroke-width="2" stroke-linecap="round"/><line x1="3" y1="8" x2="13" y2="8" stroke-width="2" stroke-linecap="round"/></svg>
+                  </button>
+                </div>
+              </div>
+            </details>
+
+            <details class="geo-acc">
+              <summary>Измерения и ГМТ</summary>
+              <div class="geo-acc-body geo-tool-grid">
+                <button id="geo-btn-measure_length" class="geo-tool-btn" onclick="geoSetTool('measure_length',this)" title="Длина отрезка — кликни на отрезок, получишь живой чип">
+                  <svg viewBox="0 0 24 24" fill="none"><line x1="3" y1="12" x2="21" y2="12" stroke-width="2"/><line x1="3" y1="8" x2="3" y2="16" stroke-width="2" stroke-linecap="round"/><line x1="21" y1="8" x2="21" y2="16" stroke-width="2" stroke-linecap="round"/></svg>
+                  Длина
+                </button>
+                <button id="geo-btn-measure_angle" class="geo-tool-btn" onclick="geoSetTool('measure_angle',this)" title="Угол — 3 клика: точка A, вершина, точка B">
+                  <svg viewBox="0 0 24 24" fill="none"><path d="M3 20 L20 20" stroke-width="2" stroke-linecap="round"/><path d="M3 20 L14 6" stroke-width="2" stroke-linecap="round"/><path d="M7 20 A10 10 0 0 1 11.5 12" stroke-width="1.5" fill="none"/></svg>
+                  Угол
+                </button>
+                <button id="geo-btn-measure_area" class="geo-tool-btn" onclick="geoSetTool('measure_area',this)" title="Площадь многоугольника — кликни на полигон">
+                  <svg viewBox="0 0 24 24" fill="none"><polygon points="12,3 21,9 18,20 6,20 3,9" stroke-width="2" fill="none"/></svg>
+                  Площадь
+                </button>
+                <button id="geo-btn-locus" class="geo-tool-btn" onclick="geoSetTool('locus',this)" title="ГМТ — выбери точку-мовер (on_segment/on_circle), затем целевую точку">
+                  <svg viewBox="0 0 24 24" fill="none"><path d="M4 20 Q8 4 12 12 Q16 20 20 6" stroke-width="2" fill="none" stroke-linecap="round" stroke-linejoin="round"/><circle cx="8" cy="14" r="2" fill="currentColor"/></svg>
+                  ГМТ
+                </button>
+                <button id="geo-btn-point_on_segment" class="geo-tool-btn" onclick="geoSetTool('point_on_segment',this)" title="Точка на отрезке — кликни на отрезок, получишь скользящую точку">
+                  <svg class="ic" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round"><line x1="3" y1="20" x2="21" y2="4"/><circle cx="12" cy="12" r="3" fill="currentColor" stroke="none"/></svg>
+                  Т. на отрезке
+                </button>
+                <button id="geo-btn-point_on_circle" class="geo-tool-btn" onclick="geoSetTool('point_on_circle',this)" title="Точка на окружности — кликни на окружность, получишь скользящую точку">
+                  <svg class="ic" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round"><circle cx="12" cy="12" r="9"/><circle cx="12" cy="3" r="2.5" fill="currentColor" stroke="none"/></svg>
+                  Т. на круге
+                </button>
+              </div>
+            </details>
+
+            <details class="geo-acc">
+              <summary>Метки</summary>
+              <div class="geo-acc-body geo-tool-grid">
+                <button id="geo-btn-tick" class="geo-tool-btn" onclick="geoSetTool('tick',this)" title="Метки равных сторон — клик на отрезок или сторону (1–3 штриха)">
+                  <svg viewBox="0 0 24 24" fill="none"><line x1="3" y1="20" x2="21" y2="4" stroke-width="1.5"/><line x1="11" y1="7" x2="8" y2="11" stroke-width="2" stroke-linecap="round"/><line x1="13" y1="9" x2="10" y2="13" stroke-width="2" stroke-linecap="round"/></svg>
+                  Штрихи
+                </button>
+                <button id="geo-btn-arcmark" class="geo-tool-btn" onclick="geoSetTool('arcmark',this)" title="Метки равных углов — клик на вершину полигона (1–3 дуги)">
+                  <svg viewBox="0 0 24 24" fill="none"><path d="M4 20 L20 20 L20 4" stroke-width="1.5" fill="none"/><path d="M8 20 A12 12 0 0 1 20 8" stroke-width="1.5" fill="none"/><path d="M11 20 A9 9 0 0 1 20 11" stroke-width="1.5" fill="none"/></svg>
+                  Дуги
+                </button>
+                <button id="geo-btn-parallelmark" class="geo-tool-btn geo-tool-wide" onclick="geoSetTool('parallelmark',this)" title="Метки параллельных сторон — клик на отрезок (1–2 стрелки)">
+                  <svg viewBox="0 0 24 24" fill="none"><line x1="3" y1="8" x2="21" y2="8" stroke-width="1.5"/><polyline points="9,5 13,8 9,11" stroke-width="1.8" fill="none" stroke-linecap="round" stroke-linejoin="round"/><line x1="3" y1="16" x2="21" y2="16" stroke-width="1.5"/><polyline points="9,13 13,16 9,19" stroke-width="1.8" fill="none" stroke-linecap="round" stroke-linejoin="round"/></svg>
+                  Параллельность
+                </button>
+              </div>
+            </details>
 
             <!-- Display options -->
             <div class="gp-section-title" style="margin-top:6px">Параметры</div>