diff --git a/public/assets/app.css b/public/assets/app.css
index b0d66d6..81f9421 100644
--- a/public/assets/app.css
+++ b/public/assets/app.css
@@ -197,6 +197,11 @@ button, input, select {
   padding: 14px;
   display: grid;
   gap: 10px;
+  cursor: grab;
+}
+
+.component-card:active {
+  cursor: grabbing;
 }
 
 .component-card__preview {
@@ -400,12 +405,19 @@ button, input, select {
   pointer-events: auto;
   cursor: pointer;
   z-index: 3;
+  opacity: 0.32;
+  transition: opacity 120ms ease, transform 120ms ease;
 }
 
 .rack-insert-zone.is-disabled {
   cursor: not-allowed;
 }
 
+.rack-insert-zone.is-preview,
+.rack-insert-zone:hover {
+  opacity: 1;
+}
+
 .rack-insert-zone__ear {
   width: 28px;
   height: calc(100% - 4px);
@@ -482,11 +494,11 @@ button, input, select {
   user-select: none;
   overflow: hidden;
   border-radius: 8px;
-  border: 1px solid rgba(34, 38, 44, 0.55);
-  background: linear-gradient(180deg, rgba(237, 241, 246, 0.96), rgba(205, 213, 222, 0.96));
+  border: 1px solid rgba(32, 36, 42, 0.8);
+  background: linear-gradient(180deg, rgba(235, 239, 244, 0.98), rgba(191, 200, 211, 0.98));
   box-shadow:
-    inset 0 1px 0 rgba(255, 255, 255, 0.9),
-    0 10px 18px rgba(5, 6, 7, 0.28);
+    inset 0 1px 0 rgba(255, 255, 255, 0.94),
+    0 8px 14px rgba(5, 6, 7, 0.24);
   touch-action: none;
   cursor: grab;
 }
@@ -509,8 +521,10 @@ button, input, select {
   display: flex;
   flex-direction: column;
   justify-content: space-between;
-  padding: 8px 10px 8px 12px;
-  background: linear-gradient(90deg, rgba(250, 251, 252, 0.86), rgba(250, 251, 252, 0.08) 38%, rgba(250, 251, 252, 0.72));
+  padding: 6px 10px 6px 10px;
+  background:
+    linear-gradient(180deg, rgba(255, 255, 255, 0.22), rgba(255, 255, 255, 0) 42%),
+    linear-gradient(90deg, rgba(255, 255, 255, 0.38), rgba(255, 255, 255, 0.06) 34%, rgba(255, 255, 255, 0.18));
 }
 
 .rack-item__face {
@@ -527,6 +541,7 @@ button, input, select {
 
 .rack-item__header strong {
   color: #17191c;
+  font-size: 1rem;
 }
 
 .rack-item__drag-hint {
@@ -537,6 +552,7 @@ button, input, select {
   color: rgba(245, 247, 250, 0.95);
   font-size: 0.72rem;
   letter-spacing: 0.04em;
+  pointer-events: none;
 }
 
 .rack-item__remove {
@@ -557,6 +573,10 @@ button, input, select {
   cursor: pointer;
 }
 
+.rack-item__remove:hover {
+  background: rgba(134, 24, 24, 0.88);
+}
+
 .subpanel {
   padding: 16px;
   display: grid;
@@ -646,7 +666,7 @@ button, input, select {
   position: relative;
   width: 100%;
   height: 100%;
-  padding: 8px 28px;
+  padding: 6px 24px;
   overflow: hidden;
 }
 
@@ -699,7 +719,7 @@ button, input, select {
 
 .device-brand {
   position: absolute;
-  top: 7px;
+  top: 6px;
   left: 36px;
   font-size: 0.72rem;
   letter-spacing: 0.04em;
@@ -710,7 +730,7 @@ button, input, select {
 .device-silkscreen {
   position: absolute;
   left: 36px;
-  bottom: 8px;
+  bottom: 6px;
   font-size: 0.7rem;
   letter-spacing: 0.12em;
   text-transform: uppercase;
@@ -765,7 +785,8 @@ button, input, select {
   position: absolute;
   left: 40px;
   right: 70px;
-  top: 22px;
+  top: 48%;
+  transform: translateY(-50%);
   grid-template-columns: repeat(12, minmax(0, 1fr));
 }
 
@@ -792,7 +813,8 @@ button, input, select {
   position: absolute;
   left: 40px;
   right: 40px;
-  top: 20px;
+  top: 48%;
+  transform: translateY(-50%);
   grid-template-columns: repeat(12, minmax(0, 1fr));
 }
 
@@ -807,10 +829,11 @@ button, input, select {
 
 .device-uplink {
   position: absolute;
-  top: 20px;
+  top: 50%;
   right: 40px;
   width: 22px;
   height: 16px;
+  transform: translateY(-50%);
   border-radius: 4px;
   border: 1px solid rgba(110, 117, 127, 0.25);
   background: linear-gradient(180deg, #5b646f, #262b31);
@@ -818,9 +841,10 @@ button, input, select {
 
 .device-sockets {
   position: absolute;
-  top: 18px;
+  top: 50%;
   left: 40px;
   right: 56px;
+  transform: translateY(-50%);
   grid-template-columns: repeat(8, minmax(0, 1fr));
   align-items: center;
 }
@@ -838,9 +862,10 @@ button, input, select {
 .device-display {
   position: absolute;
   left: 40px;
-  top: 16px;
+  top: 50%;
   width: 68px;
   height: 30px;
+  transform: translateY(-50%);
   border-radius: 8px;
   background:
     linear-gradient(180deg, rgba(46, 180, 156, 0.9), rgba(18, 97, 90, 0.92)),
@@ -852,10 +877,11 @@ button, input, select {
 
 .device-vents {
   position: absolute;
-  top: 18px;
+  top: 50%;
   right: 42px;
   width: 96px;
   height: 22px;
+  transform: translateY(-50%);
   background:
     repeating-linear-gradient(90deg, rgba(102, 108, 118, 0.36) 0 3px, transparent 3px 7px);
   opacity: 0.8;
@@ -879,8 +905,9 @@ button, input, select {
   position: absolute;
   left: 40px;
   right: 40px;
-  top: 18px;
+  top: 50%;
   height: 18px;
+  transform: translateY(-50%);
   border-radius: 4px 4px 12px 12px;
   background: linear-gradient(180deg, #d1d7df, #8f98a4);
   box-shadow: 0 5px 12px rgba(78, 82, 90, 0.18);
diff --git a/public/assets/app.js b/public/assets/app.js
index fb0f6e8..38c745e 100644
--- a/public/assets/app.js
+++ b/public/assets/app.js
@@ -9,6 +9,8 @@ const state = {
   dragPlacementId: null,
   pointerDrag: null,
   selectedComponentId: null,
+  libraryDragComponentId: null,
+  rackDropPreviewY: null,
 };
 
 const ui = {};
@@ -64,6 +66,7 @@ function bindEvents() {
   ui.exportBom.addEventListener("click", copyBomCsv);
   document.addEventListener("pointermove", handlePointerMove);
   document.addEventListener("pointerup", handlePointerUp);
+  document.addEventListener("dragend", handleLibraryDragEnd);
 }
 
 async function loadBootstrap() {
@@ -152,7 +155,7 @@ function renderLibrary() {
   ui.componentLibrary.innerHTML = filtered
     .map(
       (component) => `
-        <article class="component-card component-card--${escapeHtml(component.category)}">
+        <article class="component-card component-card--${escapeHtml(component.category)}" draggable="true" data-component-drag-id="${escapeHtml(component.id)}">
           <div class="component-card__preview">
             ${renderComponentFace(component, "library")}
           </div>
@@ -169,7 +172,7 @@ function renderLibrary() {
             <span>${formatCurrency(component.priceNet, component.currency)}</span>
           </div>
           <button type="button" data-action="select-component" data-component-id="${escapeHtml(component.id)}">
-            ${state.selectedComponentId === component.id ? "Ausgewaehlt" : "Zum Einstecken waehlen"}
+            ${state.selectedComponentId === component.id ? "Bereit zum Ziehen" : "Ins Rack ziehen"}
           </button>
         </article>
       `
@@ -182,40 +185,21 @@ function renderLibrary() {
       renderAll();
     });
   });
-}
 
-function addComponentToRack(componentId) {
-  const component = state.components.find((entry) => entry.id === componentId);
-  const rack = getCurrentRackTemplate();
-  if (!component || !rack) {
-    return;
-  }
-
-  const position = findFirstFreePosition(component.heightU);
-  if (position === null) {
-    alert("Keine freie Position fuer diese Komponente im aktuellen Rack.");
-    return;
-  }
-
-  state.placedItems.push({
-    placementId: `p${state.nextPlacementId++}`,
-    componentId: component.id,
-    y: position,
-    x: getDefaultComponentX(component),
+  ui.componentLibrary.querySelectorAll("[data-component-drag-id]").forEach((card) => {
+    card.addEventListener("dragstart", (event) => beginLibraryDrag(event, card.dataset.componentDragId));
   });
-
-  renderAll();
 }
 
 function renderSelectionInfo() {
-  const component = getComponent(state.selectedComponentId);
+  const component = getComponent(state.libraryDragComponentId || state.selectedComponentId);
   if (!component) {
     ui.selectedComponentInfo.textContent = "Kein Element ausgewaehlt";
     ui.selectedComponentInfo.classList.remove("is-active");
     return;
   }
 
-  ui.selectedComponentInfo.textContent = `${component.name} · ${component.heightU}U · freie HE-Zone anklicken`;
+  ui.selectedComponentInfo.textContent = `${component.name} · ${component.heightU}U · aus der Bibliothek ins Rack ziehen`;
   ui.selectedComponentInfo.classList.add("is-active");
 }
 
@@ -251,6 +235,10 @@ function renderRack() {
 
   const layer = document.getElementById("rack-items-layer");
   layer.style.height = "100%";
+  const bay = ui.rackGrid.querySelector(".rack-grid__bay");
+  bay.addEventListener("dragover", handleRackDragOver);
+  bay.addEventListener("drop", handleRackDrop);
+  bay.addEventListener("dragleave", handleRackDragLeave);
 
   const insertionLayer = document.getElementById("rack-insertion-layer");
   insertionLayer.innerHTML = renderInsertionZones(rack);
@@ -282,7 +270,7 @@ function renderRack() {
             <strong>${escapeHtml(component.name)}</strong>
             <div class="rack-item__meta">${component.heightU}U · ${component.depthMm} mm · ${formatCurrency(component.priceNet, component.currency)}</div>
           </div>
-          <span class="chip">${formatRackPosition(item.y)}</span>
+          <span class="chip">${formatRackPosition(item.y, component)}</span>
         </div>
         <div class="rack-item__drag-hint">Ziehen zum verschieben</div>
         <button type="button" class="rack-item__remove" data-action="remove" aria-label="Komponente entfernen">×</button>
@@ -300,19 +288,20 @@ function renderRack() {
 }
 
 function insertSelectedComponentAt(y) {
-  if (!state.selectedComponentId) {
+  const componentId = state.libraryDragComponentId || state.selectedComponentId;
+  if (!componentId) {
     return;
   }
 
-  const component = getComponent(state.selectedComponentId);
+  const component = getComponent(componentId);
   const rack = getCurrentRackTemplate();
   if (!component || !rack) {
     return;
   }
 
   const nextRect = {
-    left: getDefaultComponentX(component),
-    top: y,
+    left: 0,
+    top: snapToUnit(y),
     width: getComponentWidthPercent(component),
     height: getComponentHeightPx(component),
   };
@@ -340,9 +329,11 @@ function insertSelectedComponentAt(y) {
   state.placedItems.push({
     placementId: `p${state.nextPlacementId++}`,
     componentId: component.id,
-    y,
-    x: getDefaultComponentX(component),
+    y: snapToUnit(y),
+    x: 0,
   });
+  state.libraryDragComponentId = null;
+  state.rackDropPreviewY = null;
   state.selectedComponentId = null;
   renderAll();
 }
@@ -442,7 +433,7 @@ function renderCableSelectors() {
         if (!component) {
           return "";
         }
-        return `<option value="${escapeHtml(item.placementId)}">${escapeHtml(component.name)} @ ${formatRackPosition(item.y)}</option>`;
+        return `<option value="${escapeHtml(item.placementId)}">${escapeHtml(component.name)} @ ${formatRackPosition(item.y, component)}</option>`;
       })
     )
     .join("");
@@ -628,43 +619,6 @@ async function copyBomCsv() {
   }
 }
 
-function findFirstFreePosition(heightU) {
-  const rack = getCurrentRackTemplate();
-  if (!rack) {
-    return null;
-  }
-
-  const unitHeight = getUnitHeightPx();
-  const testHeight = heightU * unitHeight;
-  for (let y = 0; y <= getRackHeightPx(rack) - testHeight; y += unitHeight) {
-    const blocked = state.placedItems.some((item) => {
-      const otherComponent = getComponent(item.componentId);
-      if (!otherComponent) {
-        return false;
-      }
-      return rectanglesOverlap(
-        {
-          left: getDefaultComponentX(component),
-          top: y,
-          width: getComponentWidthPercent(component),
-          height: testHeight,
-        },
-        {
-          left: item.x,
-          top: item.y,
-          width: getComponentWidthPercent(otherComponent),
-          height: getComponentHeightPx(otherComponent),
-        }
-      );
-    });
-    if (!blocked) {
-      return y;
-    }
-  }
-
-  return null;
-}
-
 function getCurrentRackTemplate() {
   return state.bootstrap?.rackTemplates.find((template) => template.id === state.rackTemplateId) ?? null;
 }
@@ -701,9 +655,7 @@ function beginPointerDrag(event, item, component) {
   const rect = event.currentTarget.getBoundingClientRect();
   state.pointerDrag = {
     placementId: item.placementId,
-    offsetX: event.clientX - rect.left,
     offsetY: event.clientY - rect.top,
-    widthPercent: getComponentWidthPercent(component),
     heightPx: getComponentHeightPx(component),
   };
   event.currentTarget.setPointerCapture?.(event.pointerId);
@@ -727,12 +679,10 @@ function handlePointerMove(event) {
   }
 
   const layerRect = layer.getBoundingClientRect();
-  const widthPx = (state.pointerDrag.widthPercent / 100) * layerRect.width;
-  const xPx = clamp(event.clientX - layerRect.left - state.pointerDrag.offsetX, 0, layerRect.width - widthPx);
   const yPx = clamp(event.clientY - layerRect.top - state.pointerDrag.offsetY, 0, getRackHeightPx(rack) - state.pointerDrag.heightPx);
 
-  item.x = (xPx / layerRect.width) * 100;
-  item.y = yPx;
+  item.x = 0;
+  item.y = snapToUnit(yPx);
   renderAll();
 }
 
@@ -857,7 +807,11 @@ function renderSocketStrip(component) {
 }
 
 function renderInsertionZones(rack) {
-  const component = getComponent(state.selectedComponentId);
+  if (!state.libraryDragComponentId) {
+    return "";
+  }
+
+  const component = getComponent(state.libraryDragComponentId);
   if (!component) {
     return "";
   }
@@ -872,27 +826,28 @@ function renderInsertionZones(rack) {
       }
       return rectanglesOverlap(
         {
-          left: getDefaultComponentX(component),
+          left: 0,
           top: y,
-          width: getComponentWidthPercent(component),
+          width: 100,
           height: getComponentHeightPx(component),
         },
         {
-          left: item.x,
+          left: 0,
           top: item.y,
-          width: getComponentWidthPercent(other),
+          width: 100,
           height: getComponentHeightPx(other),
         }
       );
     });
+    const isPreview = state.rackDropPreviewY !== null && Math.abs(state.rackDropPreviewY - y) < 1;
 
     zones.push(`
       <button
         type="button"
-        class="rack-insert-zone${occupied ? " is-disabled" : ""}"
+        class="rack-insert-zone${occupied ? " is-disabled" : ""}${isPreview ? " is-preview" : ""}"
         data-action="insert-component"
         data-insert-y="${y}"
-        style="top:${y}px;height:${getComponentHeightPx(component)}px;left:${getDefaultComponentX(component)}%;width:${getComponentWidthPercent(component)}%;"
+        style="top:${y}px;height:${getComponentHeightPx(component)}px;left:0;width:100%;"
         ${occupied ? "disabled" : ""}
       >
         <span class="rack-insert-zone__ear rack-insert-zone__ear--left"></span>
@@ -921,11 +876,11 @@ function getComponentHeightPx(component) {
 }
 
 function getComponentWidthPercent(component) {
-  return component.rackStandard === "10_inch" ? 58 : 86;
+  return 100;
 }
 
 function getDefaultComponentX(component) {
-  return (100 - getComponentWidthPercent(component)) / 2;
+  return 0;
 }
 
 function getPlacementRect(item, component) {
@@ -948,6 +903,17 @@ function formatRackPosition(y) {
   return `${(y / getUnitHeightPx() + 1).toFixed(1)}U`;
 }
 
+function formatRackPosition(y, component) {
+  const rack = getCurrentRackTemplate();
+  if (!rack) {
+    return "1U";
+  }
+  const rowIndex = Math.round(y / getUnitHeightPx());
+  const componentHeightU = component?.heightU ?? 1;
+  const u = rack.totalU - rowIndex - componentHeightU + 1;
+  return `${Math.max(1, u)}U`;
+}
+
 function getPlacementOverlaps() {
   const overlaps = [];
   for (let index = 0; index < state.placedItems.length; index += 1) {
@@ -992,6 +958,86 @@ function clamp(value, min, max) {
   return Math.max(min, Math.min(max, value));
 }
 
+function snapToUnit(value) {
+  const unitHeight = getUnitHeightPx();
+  return Math.round(value / unitHeight) * unitHeight;
+}
+
+function beginLibraryDrag(event, componentId) {
+  state.libraryDragComponentId = componentId;
+  state.selectedComponentId = componentId;
+  if (event.dataTransfer) {
+    event.dataTransfer.effectAllowed = "copy";
+    event.dataTransfer.setData("text/plain", componentId);
+  }
+  window.requestAnimationFrame(() => {
+    renderAll();
+  });
+}
+
+function handleRackDragOver(event) {
+  if (!state.libraryDragComponentId) {
+    return;
+  }
+  event.preventDefault();
+  const rack = getCurrentRackTemplate();
+  const component = getComponent(state.libraryDragComponentId);
+  const layer = document.getElementById("rack-items-layer");
+  if (!rack || !component || !layer) {
+    return;
+  }
+  const rect = layer.getBoundingClientRect();
+  const y = clamp(event.clientY - rect.top - getComponentHeightPx(component) / 2, 0, getRackHeightPx(rack) - getComponentHeightPx(component));
+  const snappedY = snapToUnit(y);
+  if (state.rackDropPreviewY !== snappedY) {
+    state.rackDropPreviewY = snappedY;
+    const insertionLayer = document.getElementById("rack-insertion-layer");
+    if (insertionLayer) {
+      insertionLayer.innerHTML = renderInsertionZones(rack);
+      ui.rackGrid.querySelectorAll("[data-action='insert-component']").forEach((element) => {
+        element.addEventListener("click", () => insertSelectedComponentAt(Number(element.dataset.insertY)));
+      });
+    }
+  }
+}
+
+function handleRackDrop(event) {
+  if (!state.libraryDragComponentId) {
+    return;
+  }
+  event.preventDefault();
+  if (state.rackDropPreviewY !== null) {
+    insertSelectedComponentAt(state.rackDropPreviewY);
+  }
+}
+
+function handleRackDragLeave(event) {
+  if (!state.libraryDragComponentId) {
+    return;
+  }
+  if (event.currentTarget.contains(event.relatedTarget)) {
+    return;
+  }
+  state.rackDropPreviewY = null;
+  const rack = getCurrentRackTemplate();
+  const insertionLayer = document.getElementById("rack-insertion-layer");
+  if (rack && insertionLayer) {
+    insertionLayer.innerHTML = renderInsertionZones(rack);
+    ui.rackGrid.querySelectorAll("[data-action='insert-component']").forEach((element) => {
+      element.addEventListener("click", () => insertSelectedComponentAt(Number(element.dataset.insertY)));
+    });
+  }
+}
+
+function handleLibraryDragEnd() {
+  if (!state.libraryDragComponentId && state.rackDropPreviewY === null) {
+    return;
+  }
+  state.libraryDragComponentId = null;
+  state.rackDropPreviewY = null;
+  renderAll();
+}
+
 function applyRackColorTheme(element, color) {
   const rgb = hexToRgb(color);
   if (!rgb) {