1.7.0

package-lock.json

@@ -1,12 +1,12 @@
 {
   "name": "vue-nonograms-solid",
-  "version": "1.5.0",
+  "version": "1.7.0",
   "lockfileVersion": 3,
   "requires": true,
   "packages": {
     "": {
       "name": "vue-nonograms-solid",
-      "version": "1.5.0",
+      "version": "1.7.0",
       "dependencies": {
         "fireworks-js": "^2.10.8",
         "flag-icons": "^7.5.0",

package.json

@@ -1,6 +1,6 @@
 {
   "name": "vue-nonograms-solid",
-  "version": "1.5.0",
+  "version": "1.7.0",
   "type": "module",
   "scripts": {
     "dev": "vite",

src/components/CustomGameModal.vue

@@ -1,5 +1,5 @@
 <script setup>
-import { ref, computed } from 'vue';
+import { ref, computed, onMounted, watch, nextTick } from 'vue';
 import { usePuzzleStore } from '@/stores/puzzle';
 import { useI18n } from '@/composables/useI18n';
 import { calculateDifficulty } from '@/utils/puzzleUtils';
@@ -11,6 +11,181 @@ const { t } = useI18n();
 const customSize = ref(10);
 const fillRate = ref(50);
 const errorMsg = ref('');
+const difficultyCanvas = ref(null);
+const isDragging = ref(false);
+
+const drawMap = () => {
+  const canvas = difficultyCanvas.value;
+  if (!canvas) return;
+  const ctx = canvas.getContext('2d');
+  const width = canvas.width;
+  const height = canvas.height;
+
+  // Clear
+  ctx.clearRect(0, 0, width, height);
+
+  // Draw Gradient Background
+  // Optimization: Create an image data once if static, but here it's small enough.
+  const imgData = ctx.createImageData(width, height);
+  const data = imgData.data;
+
+  // Ranges:
+  // X: Fill Rate 10% -> 90%
+  // Y: Size 5 -> 80
+  
+  for (let y = 0; y < height; y++) {
+    for (let x = 0; x < width; x++) {
+      // Map x, y to fillRate, size
+      // y=0 -> size 80 (top), y=height -> size 5 (bottom)
+      // x=0 -> fill 10%, x=width -> fill 90%
+      
+      const normalizedX = x / width;
+      const normalizedY = 1 - (y / height); // 0 at bottom, 1 at top
+      
+      const fRate = 0.1 + normalizedX * 0.8; // 0.1 to 0.9
+      const sSize = 5 + normalizedY * 75;    // 5 to 80
+      
+      const { value } = calculateDifficulty(fRate, sSize);
+      
+      // Color Mapping:
+      // Green (0%) -> Yellow (50%) -> Red (100%)
+      // Hue: 120 -> 0
+      const hue = 120 * (1 - value / 100);
+      
+      // Convert HSL to RGB (Simplified)
+      // Saturation 100%, Lightness 50%
+      const [r, g, b] = hslToRgb(hue / 360, 1, 0.5);
+      
+      const index = (y * width + x) * 4;
+      data[index] = r;
+      data[index + 1] = g;
+      data[index + 2] = b;
+      data[index + 3] = 255; // Alpha
+    }
+  }
+  ctx.putImageData(imgData, 0, 0);
+
+  // Draw current position
+  // Map current fillRate/size to x,y
+  // Fill: 10..90. Size: 5..80.
+  const currentFill = Math.max(10, Math.min(90, fillRate.value));
+  const currentSize = Math.max(5, Math.min(80, customSize.value));
+  
+  const posX = ((currentFill - 10) / 80) * width;
+  const posY = (1 - (currentSize - 5) / 75) * height;
+
+  // Draw Crosshair/Circle
+  ctx.beginPath();
+  ctx.arc(posX, posY, 6, 0, Math.PI * 2);
+  ctx.fillStyle = '#fff';
+  ctx.fill();
+  ctx.lineWidth = 2;
+  ctx.strokeStyle = '#000';
+  ctx.stroke();
+};
+
+const hslToRgb = (h, s, l) => {
+    let r, g, b;
+    if (s === 0) {
+        r = g = b = l; // achromatic
+    } else {
+        const hue2rgb = (p, q, t) => {
+            if (t < 0) t += 1;
+            if (t > 1) t -= 1;
+            if (t < 1 / 6) return p + (q - p) * 6 * t;
+            if (t < 1 / 2) return q;
+            if (t < 2 / 3) return p + (q - p) * (2 / 3 - t) * 6;
+            return p;
+        };
+        const q = l < 0.5 ? l * (1 + s) : l + s - l * s;
+        const p = 2 * l - q;
+        r = hue2rgb(p, q, h + 1 / 3);
+        g = hue2rgb(p, q, h);
+        b = hue2rgb(p, q, h - 1 / 3);
+    }
+    return [Math.round(r * 255), Math.round(g * 255), Math.round(b * 255)];
+};
+
+const updateFromEvent = (e) => {
+    const canvas = difficultyCanvas.value;
+    if (!canvas) return;
+    const rect = canvas.getBoundingClientRect();
+    
+    // Handle Touch or Mouse
+    const clientX = e.touches ? e.touches[0].clientX : e.clientX;
+    const clientY = e.touches ? e.touches[0].clientY : e.clientY;
+    
+    let x = clientX - rect.left;
+    let y = clientY - rect.top;
+    
+    // Clamp
+    x = Math.max(0, Math.min(rect.width, x));
+    y = Math.max(0, Math.min(rect.height, y));
+    
+    // Reverse Map
+    // x / width -> fillRate (10..90)
+    // 1 - y / height -> size (5..80)
+    
+    const normalizedX = x / rect.width;
+    const normalizedY = 1 - (y / rect.height);
+    
+    const newFill = 10 + normalizedX * 80;
+    const newSize = 5 + normalizedY * 75;
+    
+    fillRate.value = Math.round(newFill);
+    customSize.value = Math.round(newSize);
+};
+
+const startDrag = (e) => {
+    isDragging.value = true;
+    updateFromEvent(e);
+};
+
+const onDrag = (e) => {
+    if (!isDragging.value) return;
+    updateFromEvent(e);
+};
+
+const stopDrag = () => {
+    isDragging.value = false;
+};
+
+const showAdvanced = ref(false);
+
+const toggleAdvanced = () => {
+    showAdvanced.value = !showAdvanced.value;
+    if (showAdvanced.value) {
+        nextTick(drawMap);
+    }
+};
+
+onMounted(() => {
+  const savedSize = localStorage.getItem('nonograms_custom_size');
+  if (savedSize && !isNaN(savedSize)) {
+    customSize.value = Math.max(5, Math.min(80, Number(savedSize)));
+  }
+  
+  const savedFillRate = localStorage.getItem('nonograms_custom_fill_rate');
+  if (savedFillRate && !isNaN(savedFillRate)) {
+    fillRate.value = Math.max(10, Math.min(90, Number(savedFillRate)));
+  }
+  
+  // Don't draw map initially if hidden
+});
+
+watch([customSize, fillRate], () => {
+    if (showAdvanced.value) {
+        drawMap();
+    }
+});
+
+watch(customSize, (newVal) => {
+  localStorage.setItem('nonograms_custom_size', newVal);
+});
+
+watch(fillRate, (newVal) => {
+  localStorage.setItem('nonograms_custom_fill_rate', newVal);
+});
 
 const snapToStep = (value, step) => {
   const rounded = Math.round(value / step) * step;
@@ -21,12 +196,12 @@ const handleSnap = () => {
   customSize.value = snapToStep(Number(customSize.value), 5);
 };
 
-const difficultyLevel = computed(() => {
-  return calculateDifficulty(fillRate.value / 100);
+const difficultyInfo = computed(() => {
+  return calculateDifficulty(fillRate.value / 100, customSize.value);
 });
 
 const difficultyColor = computed(() => {
-  switch(difficultyLevel.value) {
+  switch(difficultyInfo.value.level) {
     case 'extreme': return '#ff3333';
     case 'hardest': return '#ff9933';
     case 'harder': return '#ffff33';
@@ -51,8 +226,11 @@ const confirm = () => {
   <div class="modal-overlay" @click.self="emit('close')">
     <div class="modal glass-panel">
       <h2>{{ t('custom.title') }}</h2>
-      <p>{{ t('custom.prompt') }}</p>
       
+      <div class="modal-content">
+        <div class="sliders-section">
+          <div class="slider-container">
+            <p>{{ t('custom.prompt') }}</p>
             <div class="input-group">
               <div class="range-value">{{ customSize }}</div>
               <input 
@@ -68,7 +246,9 @@ const confirm = () => {
                 <span>80</span>
               </div>
             </div>
+          </div>
 
+          <div class="slider-container">
             <p>{{ t('custom.fillRate') }}</p>
             <div class="input-group">
               <div class="range-value">{{ fillRate }}%</div>
@@ -77,19 +257,44 @@ const confirm = () => {
                 v-model="fillRate" 
                 min="10" 
                 max="90"
-          step="5"
+                step="1"
               />
               <div class="range-scale">
                 <span>10%</span>
                 <span>90%</span>
               </div>
             </div>
+          </div>
+        </div>
+
+        <div class="map-section" v-if="showAdvanced">
+            <canvas 
+                ref="difficultyCanvas" 
+                width="200" 
+                height="200"
+                @mousedown="startDrag"
+                @mousemove="onDrag"
+                @mouseup="stopDrag"
+                @mouseleave="stopDrag"
+                @touchstart.prevent="startDrag"
+                @touchmove.prevent="onDrag"
+                @touchend="stopDrag"
+            ></canvas>
+        </div>
+      </div>
 
       <div class="difficulty-indicator">
-        <span class="label">{{ t('custom.difficulty') }}:</span>
-        <span class="value" :style="{ color: difficultyColor }">
-          {{ t(`difficulty.${difficultyLevel}`) }}
-        </span>
+        <div class="label">{{ t('custom.difficulty') }}</div>
+        <div class="difficulty-row">
+            <div class="level" :style="{ color: difficultyColor }">{{ t(`difficulty.${difficultyInfo.level}`) }}</div>
+            <div class="percentage" :style="{ color: difficultyColor }">({{ difficultyInfo.value }}%)</div>
+        </div>
+      </div>
+
+      <div class="advanced-toggle">
+          <button class="btn-text" @click="toggleAdvanced">
+              {{ showAdvanced ? 'Ukryj mapę trudności' : 'Pokaż mapę trudności' }}
+          </button>
       </div>
       
       <p v-if="errorMsg" class="error">{{ errorMsg }}</p>
@@ -121,7 +326,7 @@ const confirm = () => {
 .modal {
   padding: 40px;
   text-align: center;
-  max-width: 400px;
+  max-width: 800px;
   width: 90%;
   border: 1px solid var(--accent-cyan);
   box-shadow: 0 0 50px rgba(0, 242, 255, 0.2);
@@ -129,6 +334,44 @@ const confirm = () => {
   transition: all 0.3s ease-in-out;
 }
 
+.modal-content {
+    display: flex;
+    flex-direction: row;
+    gap: 40px;
+    align-items: center;
+    justify-content: center;
+    margin-bottom: 20px;
+}
+
+@media (max-width: 700px) {
+    .modal-content {
+        flex-direction: column;
+        gap: 20px;
+    }
+}
+
+.sliders-section {
+    flex: 1;
+    display: flex;
+    flex-direction: column;
+    align-items: center;
+}
+
+.map-section {
+    flex: 0 0 auto;
+    display: flex;
+    justify-content: center;
+    align-items: center;
+}
+
+canvas {
+    border: 2px solid var(--panel-border);
+    border-radius: 8px;
+    box-shadow: 0 0 20px rgba(0, 242, 255, 0.1);
+    cursor: crosshair;
+    background: #000;
+}
+
 h2 {
   font-size: 2rem;
   color: var(--accent-cyan);
@@ -142,6 +385,11 @@ p {
   margin-bottom: 20px;
 }
 
+.slider-container {
+    width: 100%;
+    margin-bottom: 10px;
+}
+
 .input-group {
     margin-bottom: 20px;
     display: flex;
@@ -202,14 +450,38 @@ input[type="range"]::-moz-range-thumb {
 }
 
 .difficulty-indicator {
-    margin: 20px 0;
-    font-size: 1.2rem;
+    margin: 20px 0 40px 0;
     display: flex;
-    justify-content: center;
-    gap: 10px;
+    flex-direction: column;
     align-items: center;
+    gap: 5px;
+}
+
+.difficulty-row {
+    display: flex;
+    flex-direction: row;
+    gap: 8px;
+    align-items: baseline;
+    justify-content: center;
     white-space: nowrap;
-    height: 1.5em; /* Reserve space for one line of text */
+    flex-wrap: nowrap;
+}
+
+.label {
+    font-size: 1rem;
+    color: var(--text-muted);
+}
+
+.level {
+    font-size: 1.4rem;
+    font-weight: bold;
+    text-transform: uppercase;
+    line-height: 1.2;
+}
+
+.percentage {
+    font-size: 1rem;
+    font-weight: bold;
 }
 
 .difficulty-indicator .label {
@@ -231,6 +503,25 @@ input[type="range"]::-moz-range-thumb {
     font-size: 0.9rem;
 }
 
+.btn-text {
+    background: none;
+    border: none;
+    color: var(--accent-cyan);
+    font-size: 0.9rem;
+    cursor: pointer;
+    text-decoration: underline;
+    opacity: 0.8;
+    transition: opacity 0.3s;
+}
+
+.btn-text:hover {
+    opacity: 1;
+}
+
+.advanced-toggle {
+    margin-bottom: 10px;
+}
+
 .actions {
   display: flex;
   gap: 15px;

src/components/WinModal.vue

@@ -4,7 +4,7 @@ import { Fireworks } from 'fireworks-js';
 import { usePuzzleStore } from '@/stores/puzzle';
 import { useI18n } from '@/composables/useI18n';
 import { useTimer } from '@/composables/useTimer';
-import { Download } from 'lucide-vue-next';
+import { Download, FileCode } from 'lucide-vue-next';
 import { calculateDifficulty } from '@/utils/puzzleUtils';
 
 const store = usePuzzleStore();
@@ -41,30 +41,43 @@ const playFanfare = async () => {
     }
   }
   masterGain = audioContext.createGain();
-  masterGain.gain.value = 0.18;
+  masterGain.gain.value = 0.25; // Slightly louder but softer tone
   masterGain.connect(audioContext.destination);
-  const notes = [
-    { time: 0.0, dur: 0.18, freqs: [523.25, 659.25, 783.99] },
-    { time: 0.2, dur: 0.18, freqs: [587.33, 740.0, 880.0] },
-    { time: 0.4, dur: 0.22, freqs: [659.25, 830.61, 987.77] },
-    { time: 0.7, dur: 0.35, freqs: [698.46, 880.0, 1046.5] }
-  ];
+
   const now = audioContext.currentTime;
-  notes.forEach(({ time, dur, freqs }) => {
-    freqs.forEach((freq) => {
+
+  const playNote = (freq, startTime, duration) => {
     const osc = audioContext.createOscillator();
     const gain = audioContext.createGain();
-      osc.type = 'triangle';
+    
+    // Mix of sine and triangle for a bell-like quality
+    osc.type = 'sine'; 
     osc.frequency.value = freq;
-      gain.gain.setValueAtTime(0.0001, now + time);
-      gain.gain.linearRampToValueAtTime(0.8, now + time + 0.02);
-      gain.gain.exponentialRampToValueAtTime(0.0001, now + time + dur);
+
+    // Envelope for elegant bell/chime sound
+    gain.gain.setValueAtTime(0, startTime);
+    gain.gain.linearRampToValueAtTime(0.4, startTime + 0.05); // Soft attack
+    gain.gain.exponentialRampToValueAtTime(0.01, startTime + duration); // Long release
+
     osc.connect(gain);
     gain.connect(masterGain);
-      osc.start(now + time);
-      osc.stop(now + time + dur + 0.05);
-    });
-  });
+
+    osc.start(startTime);
+    osc.stop(startTime + duration + 0.1);
+  };
+
+  // C Major 7 Arpeggio sequence (C5, E5, G5, B5, C6) - Elegant & Uplifting
+  const sequence = [
+    { freq: 523.25, time: 0.0, dur: 0.8 }, // C5
+    { freq: 659.25, time: 0.1, dur: 0.8 }, // E5
+    { freq: 783.99, time: 0.2, dur: 0.8 }, // G5
+    { freq: 987.77, time: 0.3, dur: 0.8 }, // B5 (Maj7)
+    { freq: 1046.50, time: 0.4, dur: 2.0 }, // C6 (High C resolve)
+    // Add a bass root note at the end for fullness
+    { freq: 523.25, time: 0.4, dur: 2.0 }  // C5
+  ];
+
+  sequence.forEach(note => playNote(note.freq, now + note.time, note.dur));
 };
 
 const triggerVibration = () => {
@@ -189,6 +202,125 @@ const buildShareCanvas = () => {
   return canvas;
 };
 
+const buildShareSVG = () => {
+  const grid = store.playerGrid;
+  if (!grid || !grid.length) return null;
+  
+  const appUrl = 'https://nonograms.7u.pl/';
+  const size = store.size;
+  const maxBoard = 640;
+  const cellSize = Math.max(8, Math.floor(maxBoard / size));
+  const boardSize = cellSize * size;
+  const padding = 28;
+  const headerHeight = 64;
+  const footerHeight = 28;
+  const infoHeight = 40;
+  const width = boardSize + padding * 2;
+  const height = boardSize + padding * 2 + headerHeight + footerHeight + infoHeight;
+
+  // Colors
+  const bgGradientStart = '#1b2a4a';
+  const bgGradientEnd = '#0a1324';
+  const overlayColor = 'rgba(0, 0, 0, 0.35)';
+  const textColor = '#e8fbff';
+  const gridColor = 'rgba(255, 255, 255, 0.06)';
+  const gridLineColor = 'rgba(255, 255, 255, 0.12)';
+  const filledColor = '#00f2fe';
+  const crossColor = 'rgba(255, 255, 255, 0.5)';
+  const urlColor = 'rgba(255, 255, 255, 0.75)';
+
+  // Difficulty Logic
+  const densityPercent = Math.round(store.currentDensity * 100);
+  const diffInfo = calculateDifficulty(store.currentDensity, store.size);
+  const difficultyKey = diffInfo.level;
+  let diffColor = '#33ff33';
+  if (difficultyKey === 'extreme') diffColor = '#ff3333';
+  else if (difficultyKey === 'hardest') diffColor = '#ff9933';
+  else if (difficultyKey === 'harder') diffColor = '#ffff33';
+  const difficultyText = t(`difficulty.${difficultyKey}`);
+  const diffLabel = `${t('win.difficulty')} ${difficultyText} (${densityPercent}%)`;
+
+  let svgContent = `<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 ${width} ${height}" width="${width}" height="${height}">`;
+  
+  // Background
+  svgContent += `
+    <defs>
+      <linearGradient id="bg" x1="0%" y1="0%" x2="100%" y2="100%">
+        <stop offset="0%" stop-color="${bgGradientStart}"/>
+        <stop offset="100%" stop-color="${bgGradientEnd}"/>
+      </linearGradient>
+    </defs>
+    <rect width="100%" height="100%" fill="url(#bg)"/>
+    <rect x="12" y="12" width="${width - 24}" height="${height - 24}" fill="${overlayColor}"/>
+  `;
+
+  // Text: Title & Time
+  svgContent += `
+    <text x="${padding}" y="${padding + 28}" font-family="Segoe UI, sans-serif" font-weight="700" font-size="26" fill="${textColor}">${t('app.title')}</text>
+    <text x="${padding}" y="${padding + 56}" font-family="Segoe UI, sans-serif" font-weight="600" font-size="16" fill="${textColor}">${t('win.time')} ${formattedTime.value}</text>
+  `;
+
+  // Text: Difficulty (Right Aligned - manual approx or end anchor)
+  svgContent += `
+    <text x="${width - padding}" y="${padding + 56}" font-family="Segoe UI, sans-serif" font-weight="600" font-size="14" fill="${diffColor}" text-anchor="end">${diffLabel}</text>
+  `;
+
+  const gridX = padding;
+  const gridY = padding + headerHeight;
+
+  // Grid Background
+  svgContent += `<rect x="${gridX}" y="${gridY}" width="${boardSize}" height="${boardSize}" fill="${gridColor}"/>`;
+
+  // Grid Lines
+  let gridLines = '';
+  for (let i = 0; i <= size; i++) {
+    const pos = i * cellSize;
+    // Vertical
+    gridLines += `<line x1="${gridX + pos}" y1="${gridY}" x2="${gridX + pos}" y2="${gridY + boardSize}" stroke="${gridLineColor}" stroke-width="1"/>`;
+    // Horizontal
+    gridLines += `<line x1="${gridX}" y1="${gridY + pos}" x2="${gridX + boardSize}" y2="${gridY + pos}" stroke="${gridLineColor}" stroke-width="1"/>`;
+  }
+  svgContent += gridLines;
+
+  // Cells
+  let cells = '';
+  const lineWidth = Math.max(1.5, Math.floor(cellSize * 0.12));
+  
+  for (let r = 0; r < size; r++) {
+    for (let c = 0; c < size; c++) {
+      const state = grid[r]?.[c];
+      const cx = gridX + c * cellSize;
+      const cy = gridY + r * cellSize;
+      
+      if (state === 1) { // Filled
+        cells += `<rect x="${cx + 1}" y="${cy + 1}" width="${cellSize - 2}" height="${cellSize - 2}" fill="${filledColor}"/>`;
+      } else if (state === 2) { // Cross
+        const d = cellSize * 0.6;
+        const off = cellSize * 0.2;
+        cells += `
+          <path d="M${cx + off} ${cy + off} L${cx + off + d} ${cy + off + d} M${cx + off + d} ${cy + off} L${cx + off} ${cy + off + d}" 
+          stroke="${crossColor}" stroke-width="${lineWidth}" stroke-linecap="round"/>
+        `;
+      }
+    }
+  }
+  svgContent += cells;
+
+  // Guide Usage
+  if (store.guideUsageCount > 0) {
+      const totalCells = store.size * store.size;
+      const percent = Math.min(100, Math.round((store.guideUsageCount / totalCells) * 100));
+      const guideText = t('win.usedGuide', { count: store.guideUsageCount, percent });
+      svgContent += `<text x="${padding}" y="${height - padding - footerHeight + 10}" font-family="Segoe UI, sans-serif" font-weight="600" font-size="14" fill="#ff4d4d">⚠️ ${guideText}</text>`;
+  }
+
+  // URL
+  svgContent += `<text x="${padding}" y="${height - padding + 6}" font-family="Segoe UI, sans-serif" font-weight="500" font-size="14" fill="${urlColor}">${appUrl}</text>`;
+
+  svgContent += '</svg>';
+  return svgContent;
+};
+
 const canvasToBlob = (canvas) => new Promise((resolve) => canvas.toBlob((blob) => resolve(blob), 'image/png'));
 
 const createShareBlob = async () => {
@@ -197,6 +329,20 @@ const createShareBlob = async () => {
   return canvasToBlob(canvas);
 };
 
+const downloadShareSVG = () => {
+  const svgString = buildShareSVG();
+  if (!svgString) return;
+  const blob = new Blob([svgString], { type: 'image/svg+xml' });
+  const url = URL.createObjectURL(blob);
+  const link = document.createElement('a');
+  link.href = url;
+  link.download = `nonogram-${store.size}x${store.size}.svg`;
+  document.body.appendChild(link);
+  link.click();
+  link.remove();
+  URL.revokeObjectURL(url);
+};
+
 const downloadShareImage = async () => {
   const blob = await createShareBlob();
   if (!blob) return;
@@ -345,6 +491,10 @@ onUnmounted(() => {
           <button class="btn-neon secondary share-btn" :disabled="shareInProgress" :aria-label="t('win.shareDownload')" @click="downloadShareImage">
             <Download :size="20" />
           </button>
+          <!-- Download SVG (Compact) -->
+          <button class="btn-neon secondary share-btn" :disabled="shareInProgress" aria-label="Download SVG" @click="downloadShareSVG">
+            <FileCode :size="20" />
+          </button>
         </div>
       </div>
 

src/utils/puzzleUtils.js

@@ -52,24 +52,36 @@ export function generateRandomGrid(size, density = 0.5) {
     return grid;
 }
 
-export function calculateDifficulty(density) {
+export function calculateDifficulty(density, size = 10) {
     // Shannon Entropy: H(x) = -x*log2(x) - (1-x)*log2(1-x)
     // Normalized to 0-1 range (since max entropy at 0.5 is 1)
     
     // Avoid log(0)
-    if (density <= 0 || density >= 1) return 'easy';
+    if (density <= 0 || density >= 1) return { level: 'easy', value: 0 };
     
     const entropy = -density * Math.log2(density) - (1 - density) * Math.log2(1 - density);
     
-    // Thresholds based on entropy
-    // 0.5 density -> entropy 1.0 (Extreme)
-    // 0.4/0.6 density -> entropy ~0.97 (Extreme)
-    // 0.3/0.7 density -> entropy ~0.88 (Hardest)
-    // 0.2/0.8 density -> entropy ~0.72 (Harder)
-    // <0.2/>0.8 density -> entropy <0.72 (Easy)
+    // Difficulty score combines entropy (complexity) and size (scale)
+    // We use sqrt(size) to dampen the effect of very large grids, 
+    // ensuring that density still plays a major role.
+    // Normalized against max size (80)
+    const sizeFactor = Math.sqrt(size / 80);
+    const score = entropy * sizeFactor * 100;
+    const value = Math.round(score);
     
-    if (entropy >= 0.96) return 'extreme'; // approx 38% - 62%
-    if (entropy >= 0.85) return 'hardest'; // approx 28% - 38% & 62% - 72%
-    if (entropy >= 0.65) return 'harder';  // approx 17% - 28% & 72% - 83%
-    return 'easy';
+    // Thresholds
+    let level = 'easy';
+    if (value >= 80) level = 'extreme';
+    else if (value >= 60) level = 'hardest';
+    else if (value >= 40) level = 'harder';
+    else if (value >= 20) level = 'medium'; // Using 'medium' key if available, or we need to add it?
+    // Wait, useI18n only has: easy, harder, hardest, extreme.
+    // Let's stick to those keys but adjust ranges.
+    
+    if (value >= 75) level = 'extreme';
+    else if (value >= 50) level = 'hardest';
+    else if (value >= 25) level = 'harder';
+    else level = 'easy';
+
+    return { level, value };
 }

src/workers/solverWorker.js

@@ -91,16 +91,34 @@ const solveLineLogic = (lineState, hints) => {
       return result;
     }
     const len = hints[hintIndex];
+    // maxStart logic: we need enough space for this block (len) + subsequent blocks/gaps (suffixMin[hintIndex+1])
+    // suffixMin[hintIndex] = len + (m - hintIndex - 1) + suffixMin[hintIndex+1]
+    // Actually suffixMin[hintIndex] already includes everything needed from here to end.
+    // So if we place block at start, end is start + len.
+    // Total space needed is suffixMin[hintIndex].
+    // So start can go up to n - suffixMin[hintIndex].
     const maxStart = n - suffixMin[hintIndex];
+    
     for (let start = pos; start <= maxStart; start++) {
-      if (hasFilled(pos, start)) continue;
-      if (hasCross(start, start + len)) continue;
-      if (start + len < n && lineState[start + len] === 1) continue;
-      const nextPos = start + len < n ? start + len + 1 : start + len;
+      if (hasFilled(pos, start)) continue; // Must be empty before this block
+      if (hasCross(start, start + len)) continue; // Block space must be free of crosses
+      
+      // If not the last block, we need a gap after
+      if (hintIndex < m - 1) {
+          if (start + len < n && lineState[start + len] === 1) continue; // Gap must not be filled
+          // We can assume gap is at start + len. Next block starts at least at start + len + 1
+          const nextPos = start + len + 1;
           if (canPlaceSuffix(nextPos, hintIndex + 1)) {
             memoSuffix[pos][hintIndex] = true;
             return true;
           }
+      } else {
+          // Last block
+          // Check if we can fill the rest with empty
+          if (hasFilled(start + len, n)) continue;
+          memoSuffix[pos][hintIndex] = true;
+          return true;
+      }
     }
     memoSuffix[pos][hintIndex] = false;
     return false;
@@ -115,17 +133,43 @@ const solveLineLogic = (lineState, hints) => {
       return result;
     }
     const len = hints[hintCount - 1];
-    const maxStart = pos - len;
+    
+    // Logic for prefix:
+    // We are placing the (hintCount-1)-th block ending at 'start + len' <= pos.
+    // So 'start' <= pos - len.
+    // But we also need to ensure there is space for previous blocks.
+    // However, the simple constraint is just iterating backwards.
+    
+    // maxStart: if this is the only block, maxStart = pos - len.
+    // If there are previous blocks, we need a gap before this block.
+    // So previous block ended at start - 1.
+    // Actually the recursive call will handle space check.
+    // But for the gap check:
+    // If we place block at 'start', we need lineState[start-1] != 1 (if start > 0).
+    // And we recursively check canPlacePrefix(start-1, count-1).
+    // But if start=0 and count > 1, impossible.
+    
+    const maxStart = pos - len; // Simplified, loop condition handles rest
+    
     for (let start = maxStart; start >= 0; start--) {
       if (hasCross(start, start + len)) continue;
-      if (start + len < pos && lineState[start + len] === 1) continue;
-      if (hasFilled(start + len, pos)) continue;
-      if (start > 0 && lineState[start - 1] === 1) continue;
-      const prevPos = start > 0 ? start - 1 : 0;
+      if (hasFilled(start + len, pos)) continue; // Must be empty after this block up to pos
+      
+      // Check gap before
+      if (hintCount > 1) {
+          if (start === 0) continue; // No space for previous blocks
+          if (lineState[start - 1] === 1) continue; // Gap must not be filled
+          const prevPos = start - 1;
           if (canPlacePrefix(prevPos, hintCount - 1)) {
             memoPrefix[pos][hintCount] = true;
             return true;
           }
+      } else {
+          // First block
+          if (hasFilled(0, start)) continue; // Before first block must be empty
+          memoPrefix[pos][hintCount] = true;
+          return true;
+      }
     }
     memoPrefix[pos][hintCount] = false;
     return false;
@@ -136,7 +180,14 @@ const solveLineLogic = (lineState, hints) => {
     const len = hints[i];
     const starts = [];
     for (let start = 0; start <= n - len; start++) {
-      if (!canPlacePrefix(start, i)) continue;
+      if (i === 0) {
+        if (!canPlacePrefix(start, 0)) continue;
+      } else {
+        if (start === 0) continue;
+        if (lineState[start - 1] === 1) continue;
+        if (!canPlacePrefix(start - 1, i)) continue;
+      }
+
       if (hasCross(start, start + len)) continue;
       if (start + len < n && lineState[start + len] === 1) continue;
       const nextPos = start + len < n ? start + len + 1 : start + len;