diff --git a/src/assets/styles/variables.scss b/src/assets/styles/variables.scss
index 1dd4be8..0bddff8 100644
--- a/src/assets/styles/variables.scss
+++ b/src/assets/styles/variables.scss
@@ -25,6 +25,7 @@ $unit-20x: $unit * 20;
 /* Page properties
  * -------------------------------------------------------------------------- */
 $page-corner-radius: $unit;
+$image-corner-radius: $unit-2x;
 $card-corner-radius: $unit-3x;
 
 $page-top-margin: $unit-6x;
diff --git a/src/lib/components/ImagePost.svelte b/src/lib/components/ImagePost.svelte
index d50bedf..1c4e1e9 100644
--- a/src/lib/components/ImagePost.svelte
+++ b/src/lib/components/ImagePost.svelte
@@ -1,4 +1,6 @@
 <script lang="ts">
+	import Lightbox from './Lightbox.svelte'
+
 	let {
 		images = [],
 		alt = ''
@@ -8,46 +10,98 @@
 	} = $props()
 
 	let selectedIndex = $state(0)
+	let lightboxOpen = $state(false)
+	let windowWidth = $state(0)
 	
+	// Calculate columns based on breakpoints
+	const columnsPerRow = $derived(windowWidth <= 400 ? 3 : windowWidth <= 600 ? 4 : 6)
+	const totalSlots = $derived(Math.ceil(images.length / columnsPerRow) * columnsPerRow)
+
 	const selectImage = (index: number) => {
 		selectedIndex = index
 	}
+
+	const openLightbox = (index?: number) => {
+		if (index !== undefined) {
+			selectedIndex = index
+		}
+		lightboxOpen = true
+	}
+	
+	// Track window width for responsive columns
+	$effect(() => {
+		windowWidth = window.innerWidth
+		
+		const handleResize = () => {
+			windowWidth = window.innerWidth
+		}
+		
+		window.addEventListener('resize', handleResize)
+		
+		return () => {
+			window.removeEventListener('resize', handleResize)
+		}
+	})
 </script>
 
 {#if images.length === 1}
 	<!-- Single image -->
-	<div class="single-image">
+	<button class="single-image image-button" onclick={() => openLightbox()}>
 		<img src={images[0]} {alt} />
-	</div>
+	</button>
 {:else if images.length > 1}
 	<!-- Slideshow -->
 	<div class="slideshow">
-		<div class="main-image">
+		<button class="main-image image-button" onclick={() => openLightbox()}>
 			<img src={images[selectedIndex]} alt="{alt} {selectedIndex + 1}" />
-		</div>
+		</button>
 		<div class="thumbnails">
-			{#each images as image, index}
-				<button 
-					class="thumbnail" 
-					class:active={index === selectedIndex}
-					onclick={() => selectImage(index)}
-					aria-label="View image {index + 1}"
-				>
-					<img src={image} alt="{alt} thumbnail {index + 1}" />
-				</button>
+			{#each Array(totalSlots) as _, index}
+				{#if index < images.length}
+					<button
+						class="thumbnail"
+						class:active={index === selectedIndex}
+						onclick={() => selectImage(index)}
+						aria-label="View image {index + 1}"
+					>
+						<img src={images[index]} alt="{alt} thumbnail {index + 1}" />
+					</button>
+				{:else}
+					<div class="thumbnail placeholder" aria-hidden="true"></div>
+				{/if}
 			{/each}
 		</div>
 	</div>
 {/if}
 
+<Lightbox {images} bind:selectedIndex bind:isOpen={lightboxOpen} {alt} />
+
 <style lang="scss">
+	.image-button {
+		border: none;
+		padding: 0;
+		background: none;
+		cursor: pointer;
+		display: block;
+		width: 100%;
+		transition: transform 0.2s ease;
+
+		&:hover {
+			transform: scale(0.98);
+		}
+
+		&:focus {
+			outline: 2px solid $red-60;
+			outline-offset: 2px;
+		}
+	}
+
 	.single-image,
 	.main-image {
-		width: 100%;
 		aspect-ratio: 4 / 3;
-		border-radius: $card-corner-radius;
+		border-radius: $image-corner-radius;
 		overflow: hidden;
-		
+
 		img {
 			width: 100%;
 			height: 100%;
@@ -63,65 +117,74 @@
 
 	.thumbnails {
 		display: grid;
-		grid-template-columns: repeat(auto-fill, minmax(calc(25% - 12px), 1fr));
+		grid-template-columns: repeat(6, 1fr);
 		gap: $unit-2x;
-		
+
 		@media (max-width: 600px) {
-			grid-template-columns: repeat(auto-fill, minmax(calc(33.33% - 11px), 1fr));
+			grid-template-columns: repeat(4, 1fr);
 		}
-		
+
 		@media (max-width: 400px) {
-			grid-template-columns: repeat(auto-fill, minmax(calc(50% - 8px), 1fr));
+			grid-template-columns: repeat(3, 1fr);
 		}
 	}
 
 	.thumbnail {
 		position: relative;
 		aspect-ratio: 1;
-		border-radius: $card-corner-radius;
+		border-radius: $image-corner-radius;
 		overflow: hidden;
 		border: none;
 		padding: 0;
 		background: none;
 		cursor: pointer;
 		transition: all 0.2s ease;
-		
+
 		&::before {
 			content: '';
 			position: absolute;
 			inset: 0;
-			border-radius: $card-corner-radius;
+			border-radius: $image-corner-radius;
 			border: 4px solid transparent;
 			z-index: 2;
 			pointer-events: none;
 			transition: border-color 0.2s ease;
 		}
-		
+
 		&::after {
 			content: '';
 			position: absolute;
 			inset: 4px;
-			border-radius: calc($card-corner-radius - 4px);
+			border-radius: calc($image-corner-radius - 4px);
 			border: 4px solid transparent;
 			z-index: 3;
 			pointer-events: none;
 			transition: border-color 0.2s ease;
 		}
-		
+
 		&:hover {
 			transform: scale(0.98);
 		}
-		
+
 		&.active {
 			&::before {
 				border-color: $red-60;
 			}
-			
+
 			&::after {
 				border-color: $grey-100;
 			}
 		}
 		
+		&.placeholder {
+			background: $grey-90;
+			cursor: default;
+			
+			&:hover {
+				transform: none;
+			}
+		}
+
 		img {
 			width: 100%;
 			height: 100%;
@@ -130,4 +193,4 @@
 			z-index: 1;
 		}
 	}
-</style>
\ No newline at end of file
+</style>
diff --git a/src/lib/components/Lightbox.svelte b/src/lib/components/Lightbox.svelte
new file mode 100644
index 0000000..3159949
--- /dev/null
+++ b/src/lib/components/Lightbox.svelte
@@ -0,0 +1,266 @@
+<script lang="ts">
+	import { onMount } from 'svelte'
+	import { fade, scale } from 'svelte/transition'
+	
+	let {
+		images = [],
+		selectedIndex = $bindable(0),
+		isOpen = $bindable(false),
+		alt = ''
+	}: {
+		images: string[]
+		selectedIndex: number
+		isOpen: boolean
+		alt?: string
+	} = $props()
+
+	const close = () => {
+		isOpen = false
+	}
+
+	const selectImage = (index: number) => {
+		selectedIndex = index
+	}
+
+	const handleKeydown = (event: KeyboardEvent) => {
+		if (!isOpen) return
+
+		switch (event.key) {
+			case 'Escape':
+				close()
+				break
+			case 'ArrowLeft':
+				if (selectedIndex > 0) {
+					selectedIndex--
+				}
+				break
+			case 'ArrowRight':
+				if (selectedIndex < images.length - 1) {
+					selectedIndex++
+				}
+				break
+		}
+	}
+
+	const handleBackgroundClick = (event: MouseEvent) => {
+		if (event.target === event.currentTarget) {
+			close()
+		}
+	}
+
+	$effect(() => {
+		if (isOpen) {
+			// Lock scroll when lightbox opens
+			document.body.style.overflow = 'hidden'
+		} else {
+			// Restore scroll when lightbox closes
+			document.body.style.overflow = ''
+		}
+		
+		// Cleanup on unmount
+		return () => {
+			document.body.style.overflow = ''
+		}
+	})
+
+	onMount(() => {
+		window.addEventListener('keydown', handleKeydown)
+		
+		return () => {
+			window.removeEventListener('keydown', handleKeydown)
+		}
+	})
+</script>
+
+{#if isOpen}
+	<div 
+		class="lightbox-backdrop" 
+		onclick={handleBackgroundClick}
+		transition:fade={{ duration: 200 }}
+		role="button"
+		tabindex="-1"
+	>
+		<div class="lightbox-content" onclick={(e) => e.stopPropagation()}>
+			<div class="lightbox-image-container">
+				<img 
+					src={images[selectedIndex]} 
+					alt="{alt} {selectedIndex + 1}"
+					transition:scale={{ duration: 200, start: 0.9 }}
+				/>
+			</div>
+			
+			{#if images.length > 1}
+				<div class="lightbox-thumbnails">
+					<div class="thumbnails-inner">
+						{#each images as image, index}
+							<button 
+								class="lightbox-thumbnail" 
+								class:active={index === selectedIndex}
+								onclick={() => selectImage(index)}
+								aria-label="View image {index + 1}"
+							>
+								<img src={image} alt="{alt} thumbnail {index + 1}" />
+							</button>
+						{/each}
+					</div>
+				</div>
+			{/if}
+		</div>
+		
+		<button class="lightbox-close" onclick={close} aria-label="Close lightbox">
+			<svg width="24" height="24" viewBox="0 0 24 24" fill="none" xmlns="http://www.w3.org/2000/svg">
+				<path d="M18 6L6 18M6 6l12 12" stroke="currentColor" stroke-width="2" stroke-linecap="round"/>
+			</svg>
+		</button>
+	</div>
+{/if}
+
+<style lang="scss">
+	.lightbox-backdrop {
+		position: fixed;
+		inset: 0;
+		background: rgba(0, 0, 0, 0.9);
+		z-index: 1000;
+		display: flex;
+		align-items: center;
+		justify-content: center;
+		padding: $unit-4x;
+		user-select: none;
+	}
+
+	.lightbox-content {
+		width: 100%;
+		height: 100%;
+		display: flex;
+		flex-direction: column;
+		align-items: center;
+		justify-content: center;
+		position: relative;
+	}
+
+	.lightbox-image-container {
+		flex: 1;
+		display: flex;
+		align-items: center;
+		justify-content: center;
+		width: 100%;
+		overflow: hidden;
+		padding-bottom: 120px; // Space for thumbnails
+		
+		img {
+			max-width: 90vw;
+			max-height: 80vh;
+			object-fit: contain;
+			user-select: none;
+			-webkit-user-drag: none;
+		}
+	}
+
+	.lightbox-thumbnails {
+		position: fixed;
+		bottom: $unit-3x; // 24px from bottom
+		left: 50%;
+		transform: translateX(-50%);
+		display: flex;
+		justify-content: center;
+	}
+
+	.thumbnails-inner {
+		display: flex;
+		gap: $unit-2x;
+		overflow-x: auto;
+		max-width: 90vw;
+		padding: $unit $unit-2x; // Add vertical padding to prevent clipping
+		
+		&::-webkit-scrollbar {
+			display: none;
+		}
+	}
+
+	.lightbox-thumbnail {
+		position: relative;
+		width: 80px;
+		height: 80px;
+		flex-shrink: 0;
+		border-radius: $unit-2x; // 16px
+		overflow: hidden;
+		border: none;
+		padding: 0;
+		background: none;
+		cursor: pointer;
+		opacity: 0.5;
+		transition: all 0.2s ease;
+		
+		&::before {
+			content: '';
+			position: absolute;
+			inset: 0;
+			border-radius: $unit-2x;
+			border: 2px solid transparent;
+			z-index: 2;
+			pointer-events: none;
+			transition: border-color 0.2s ease;
+		}
+		
+		&::after {
+			content: '';
+			position: absolute;
+			inset: 2px;
+			border-radius: calc($unit-2x - 2px);
+			border: 2px solid transparent;
+			z-index: 3;
+			pointer-events: none;
+			transition: border-color 0.2s ease;
+		}
+		
+		&:hover {
+			opacity: 1;
+			transform: scale(1.05);
+		}
+		
+		&.active {
+			opacity: 1;
+			
+			&::before {
+				border-color: $red-60;
+			}
+			
+			&::after {
+				border-color: $grey-00; // Black inner border
+			}
+		}
+		
+		img {
+			width: 100%;
+			height: 100%;
+			object-fit: cover;
+			position: relative;
+			z-index: 1;
+			user-select: none;
+			-webkit-user-drag: none;
+		}
+	}
+
+	.lightbox-close {
+		position: absolute;
+		top: $unit-3x;
+		right: $unit-3x;
+		width: 48px;
+		height: 48px;
+		border-radius: 50%;
+		border: none;
+		background: rgba(255, 255, 255, 0.1);
+		color: $grey-100;
+		cursor: pointer;
+		display: flex;
+		align-items: center;
+		justify-content: center;
+		transition: all 0.2s ease;
+		backdrop-filter: blur(10px);
+		
+		&:hover {
+			background: rgba(255, 255, 255, 0.2);
+			transform: scale(1.1);
+		}
+	}
+</style>
\ No newline at end of file