src/static/css/style.css

@@ -5659,15 +5659,26 @@ body.tutorial-active .tutorial-cursor {
 }
 .pipeline-stage {
     position: relative;
-    overflow-x: auto;
+    overflow: visible;
-    overflow-y: visible;
 }
 .pipeline-track {
+    display: flex;
+    flex-direction: column;
+    align-items: stretch;
+    gap: 0;
+    padding: var(--sp-md) 0;
+    width: 100%;
+}
+.pipeline-row {
     display: flex;
     align-items: stretch;
     gap: var(--sp-md);
-    min-width: max-content;
+    flex-wrap: nowrap;
-    padding: var(--sp-md) 0;
+}
+.pipeline-row[data-direction="ltr"] { justify-content: flex-start; }
+.pipeline-row[data-direction="rtl"] {
+    flex-direction: row-reverse;
+    justify-content: flex-start;
 }
 .pipeline-empty {
     text-align: center;
@@ -5797,6 +5808,61 @@ body.tutorial-active .tutorial-cursor {
     to   { background-position: 12px 0; }
 }
 
+/* Pfeil in rtl-Reihe: Pfeilkopf nach links, Animation rückwärts */
+.pipeline-row[data-direction="rtl"] .pipeline-arrow::after {
+    border-left: none;
+    border-right: 6px solid var(--border);
+    right: auto;
+    left: -4px;
+}
+.pipeline-row[data-direction="rtl"] .pipeline-arrow.is-flowing::after {
+    border-right-color: var(--accent);
+    border-left-color: transparent;
+}
+.pipeline-row[data-direction="rtl"] .pipeline-arrow.is-flowing {
+    animation: pipelineFlowReverse 0.8s linear infinite;
+}
+@keyframes pipelineFlowReverse {
+    from { background-position: 12px 0; }
+    to   { background-position: 0 0; }
+}
+
+/* U-Turn-Pfeil zwischen Snake-Reihen */
+.pipeline-uturn {
+    height: 36px;
+    width: 100%;
+    margin: var(--sp-xs) 0;
+    pointer-events: none;
+    overflow: visible;
+}
+.pipeline-uturn svg {
+    width: 100%;
+    height: 100%;
+    overflow: visible;
+}
+.pipeline-uturn-path {
+    fill: none;
+    stroke: var(--border);
+    stroke-width: 2;
+    stroke-linecap: round;
+}
+.pipeline-uturn-head {
+    fill: none;
+    stroke: var(--border);
+    stroke-width: 2;
+    stroke-linecap: round;
+    stroke-linejoin: round;
+}
+.pipeline-uturn.is-flowing .pipeline-uturn-path {
+    stroke: var(--accent);
+    stroke-dasharray: 8 6;
+    animation: pipelineUturnDash 0.9s linear infinite;
+}
+.pipeline-uturn.is-flowing .pipeline-uturn-head { stroke: var(--accent); }
+@keyframes pipelineUturnDash {
+    to { stroke-dashoffset: -28; }
+}
+
 .pipeline-loop {
     position: absolute;
     bottom: -10px;
@@ -5928,7 +5994,14 @@ body.tutorial-active .tutorial-cursor {
 }
 
 @media (max-width: 900px) {
-    .pipeline-track { flex-direction: column; min-width: auto; align-items: stretch; }
+    /* Snake aufloesen — alle Reihen werden vertikal gestapelt */
+    .pipeline-row,
+    .pipeline-row[data-direction="rtl"] {
+        flex-direction: column;
+        align-items: stretch;
+    }
+    .pipeline-uturn { display: none; }
+
     .pipeline-block { flex: 0 0 auto; width: 100%; min-height: auto; flex-direction: row; padding: var(--sp-md); text-align: left; gap: var(--sp-md); }
     .pipeline-block-icon { width: 28px; height: 28px; margin-bottom: 0; flex-shrink: 0; }
     .pipeline-block-title { margin-bottom: 2px; }
@@ -5941,8 +6014,10 @@ body.tutorial-active .tutorial-cursor {
         align-self: center;
         background: var(--border);
     }
-    .pipeline-arrow::after {
+    .pipeline-arrow::after,
+    .pipeline-row[data-direction="rtl"] .pipeline-arrow::after {
         right: 50%;
+        left: auto;
         top: auto;
         bottom: -4px;
         border-top: 6px solid var(--border);
@@ -5951,12 +6026,18 @@ body.tutorial-active .tutorial-cursor {
         border-right: 4px solid transparent;
         transform: translateX(50%);
     }
-    .pipeline-arrow.is-flowing {
+    .pipeline-arrow.is-flowing,
+    .pipeline-row[data-direction="rtl"] .pipeline-arrow.is-flowing {
         background: linear-gradient(180deg, var(--accent), var(--accent) 50%, transparent 50%, transparent);
         background-size: 100% 12px;
         animation: pipelineFlowVertical 0.8s linear infinite;
     }
-    .pipeline-arrow.is-flowing::after { border-top-color: var(--accent); }
+    .pipeline-arrow.is-flowing::after,
+    .pipeline-row[data-direction="rtl"] .pipeline-arrow.is-flowing::after {
+        border-top-color: var(--accent);
+        border-right-color: transparent;
+        border-left-color: transparent;
+    }
     @keyframes pipelineFlowVertical {
         from { background-position: 0 0; }
         to   { background-position: 0 12px; }

src/static/js/pipeline.js

@@ -165,20 +165,15 @@ const Pipeline = {
         }, 600);
     },
 
-    /** Vollbild-Pipeline (Tab "Analysepipeline") rendern. */
+    /** Vollbild-Pipeline (Tab "Analysepipeline") als 3x3-Snake rendern. */
     _render() {
         const stage = document.getElementById('pipeline-stage');
         const meta = document.getElementById('pipeline-header-meta');
         const sidenote = document.getElementById('pipeline-sidenote');
         if (!stage) return;
 
-        // Header: letzter Refresh
+        if (meta) meta.textContent = this._formatHeader();
-        if (meta) {
+        if (sidenote) sidenote.hidden = !this._isResearch;
-            meta.textContent = this._formatHeader();
-        }
-        if (sidenote) {
-            sidenote.hidden = !this._isResearch;
-        }
 
         // Brandneue Lage ohne Refresh
         if (!this._lastRefreshHeader) {
@@ -186,26 +181,55 @@ const Pipeline = {
             return;
         }
 
-        // Steps + Pfeile
+        // Sichtbare Blöcke (skipped komplett ausgeblendet — Anforderung 4b)
         const visible = (this._definition || []).filter(s => {
             const st = this._stateByKey[s.key];
-            // Übersprungene komplett ausblenden (laut Anforderung 4b)
             return !st || st.status !== 'skipped';
         });
 
-        const blocksHtml = visible.map((s, i) => this._renderBlock(s, i, visible.length)).join('');
+        // In Dreier-Reihen aufteilen, Snake-Direction abwechselnd
-        stage.innerHTML = `<div class="pipeline-track">${blocksHtml}</div>`;
+        const ROW_SIZE = 3;
+        const rows = [];
+        for (let i = 0; i < visible.length; i += ROW_SIZE) {
+            rows.push({
+                steps: visible.slice(i, i + ROW_SIZE),
+                direction: (rows.length % 2 === 0) ? 'ltr' : 'rtl',
+            });
+        }
+
+        let trackHtml = '';
+        rows.forEach((row, rowIdx) => {
+            const isLastRow = rowIdx === rows.length - 1;
+            let rowHtml = `<div class="pipeline-row" data-direction="${row.direction}">`;
+            row.steps.forEach((s, i) => {
+                const isLastBlockOverall = isLastRow && i === row.steps.length - 1;
+                rowHtml += this._renderBlock(s, isLastBlockOverall);
+                // Inner-Pfeil zwischen Blöcken einer Reihe (nicht hinter dem letzten)
+                if (i < row.steps.length - 1) {
+                    rowHtml += `<div class="pipeline-arrow" data-from="${s.key}" data-arrow-type="inner"></div>`;
+                }
+            });
+            rowHtml += '</div>';
+            trackHtml += rowHtml;
+
+            // U-Turn-Pfeil zwischen dieser und der nächsten Reihe
+            if (!isLastRow) {
+                const lastInRow = row.steps[row.steps.length - 1];
+                const side = row.direction === 'ltr' ? 'right' : 'left';
+                trackHtml += this._renderUturn(side, lastInRow.key);
+            }
+        });
+
+        stage.innerHTML = `<div class="pipeline-track">${trackHtml}</div>`;
         this._bindBlockEvents(stage);
     },
 
-    _renderBlock(stepDef, index, total) {
+    _renderBlock(stepDef, isLastOverall) {
         const st = this._stateByKey[stepDef.key];
         const status = (st && st.status) || 'pending';
         const cv = st ? st.count_value : null;
         const cs = st ? st.count_secondary : null;
-        const isLast = (index === total - 1);
+        const loopMark = isLastOverall && this._isResearch
-        const arrow = isLast ? '' : `<div class="pipeline-arrow" data-from="${stepDef.key}"></div>`;
-        const loopMark = isLast && this._isResearch
             ? `<div class="pipeline-loop" title="Mehrfach-Durchlauf"><svg viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round"><path d="M21 12a9 9 0 1 1-3-6.7"/><path d="M21 4v5h-5"/></svg></div>`
             : '';
         const icon = this._icons[stepDef.icon] || this._icons.search;
@@ -219,7 +243,26 @@ const Pipeline = {
                 </div>
                 ${loopMark}
             </div>
-            ${arrow}
+        `;
+    },
+
+    /** U-Turn-Pfeil zwischen zwei Reihen (Snake-Übergang). */
+    _renderUturn(side, fromKey) {
+        // SVG-Bogen + Pfeilkopf, side="right" startet rechts oben, "left" startet links oben.
+        // viewBox: 100 wide, 44 high
+        const path = side === 'right'
+            ? 'M 92 0 L 92 18 A 14 14 0 0 1 78 32 L 8 32'
+            : 'M 8 0 L 8 18 A 14 14 0 0 0 22 32 L 92 32';
+        const head = side === 'right'
+            ? '<polyline points="14,26 8,32 14,38"/>'
+            : '<polyline points="86,26 92,32 86,38"/>';
+        return `
+            <div class="pipeline-uturn" data-side="${side}" data-from="${fromKey}" data-arrow-type="uturn" aria-hidden="true">
+                <svg viewBox="0 0 100 44" preserveAspectRatio="none">
+                    <path d="${path}" class="pipeline-uturn-path"/>
+                    <g class="pipeline-uturn-head">${head}</g>
+                </svg>
+            </div>
         `;
     },
 
@@ -251,12 +294,12 @@ const Pipeline = {
         const cEl = block.querySelector('.pipeline-block-count');
         if (cEl) cEl.innerHTML = this._formatCount(stepKey, cv, cs, status);
 
-        // Aktiven Pfeil zum nächsten Block markieren
+        // Aktiven Pfeil/U-Turn zum nächsten Block markieren (alles mit data-from)
-        const arrows = stage.querySelectorAll('.pipeline-arrow');
+        stage.querySelectorAll('.pipeline-arrow, .pipeline-uturn')
-        arrows.forEach(a => a.classList.remove('is-flowing'));
+             .forEach(a => a.classList.remove('is-flowing'));
         if (status === 'done') {
-            const arrow = stage.querySelector(`.pipeline-arrow[data-from="${stepKey}"]`);
+            const next = stage.querySelector(`[data-from="${stepKey}"]`);
-            if (arrow) arrow.classList.add('is-flowing');
+            if (next) next.classList.add('is-flowing');
         }
     },