Feature: 40 bilingual questions, random 10 game run, difficulty levels, and full i18n support

app/static/css/style.css

@@ -83,6 +83,41 @@ body {
     gap: 10px;
 }
 
+.lang-switch-group {
+    display: inline-flex;
+    background: rgba(20, 22, 40, 0.85);
+    border: 1px solid var(--border-gold);
+    border-radius: 20px;
+    padding: 2px;
+    overflow: hidden;
+}
+
+.lang-btn {
+    background: transparent;
+    border: none;
+    color: var(--text-muted);
+    font-size: 0.8rem;
+    font-weight: 600;
+    padding: 4px 9px;
+    border-radius: 16px;
+    cursor: pointer;
+    transition: all 0.2s ease;
+    min-height: 28px;
+    display: flex;
+    align-items: center;
+    gap: 4px;
+}
+
+.lang-btn:hover {
+    color: var(--gold);
+}
+
+.lang-btn.active {
+    background: var(--gold);
+    color: #0b0b16;
+    box-shadow: 0 0 8px rgba(201, 168, 106, 0.4);
+}
+
 .audio-btn {
     background: rgba(201, 168, 106, 0.15);
     border: 1px solid var(--gold);
@@ -302,6 +337,57 @@ body {
     color: var(--text-muted);
 }
 
+.difficulty-selection {
+    margin: 18px 0 22px;
+    display: flex;
+    flex-direction: column;
+    align-items: center;
+    gap: 10px;
+}
+
+.difficulty-label {
+    font-size: 0.95rem;
+    color: var(--gold-soft);
+    font-weight: 600;
+}
+
+.difficulty-chips {
+    display: flex;
+    flex-wrap: wrap;
+    gap: 8px;
+    justify-content: center;
+}
+
+.diff-chip {
+    background: rgba(255, 255, 255, 0.05);
+    border: 1px solid var(--border-gold);
+    color: var(--text-muted);
+    border-radius: 20px;
+    padding: 8px 16px;
+    font-size: 0.88rem;
+    cursor: pointer;
+    display: inline-flex;
+    align-items: center;
+    gap: 6px;
+    transition: all 0.2s ease;
+    font-family: inherit;
+}
+
+.diff-chip:hover {
+    border-color: var(--gold);
+    color: var(--text-main);
+    transform: translateY(-1px);
+    background: rgba(201, 168, 106, 0.12);
+}
+
+.diff-chip.active {
+    background: rgba(201, 168, 106, 0.25);
+    border-color: var(--gold);
+    color: var(--gold-bright);
+    box-shadow: 0 0 10px rgba(201, 168, 106, 0.35);
+    font-weight: bold;
+}
+
 /* =========================================
    BUTTONS
    ========================================= */
@@ -446,6 +532,13 @@ body {
     gap: 8px;
 }
 
+.meta-left {
+    display: flex;
+    align-items: center;
+    gap: 8px;
+    flex-wrap: wrap;
+}
+
 .badge {
     padding: 4px 10px;
     border-radius: 12px;
@@ -457,6 +550,30 @@ body {
     white-space: nowrap;
 }
 
+.badge-diff {
+    background: rgba(255, 255, 255, 0.06);
+    border: 1px solid rgba(255, 255, 255, 0.2);
+    color: var(--text-main);
+}
+
+.badge-diff-easy {
+    background: rgba(46, 204, 113, 0.15);
+    border-color: #2ecc71;
+    color: #2ecc71;
+}
+
+.badge-diff-medium {
+    background: rgba(243, 156, 18, 0.15);
+    border-color: #f39c12;
+    color: #f39c12;
+}
+
+.badge-diff-hard {
+    background: rgba(231, 76, 60, 0.15);
+    border-color: #e74c3c;
+    color: #e74c3c;
+}
+
 .badge-warning {
     background: rgba(243, 156, 18, 0.2);
     border-color: var(--warning);
@@ -1055,4 +1172,14 @@ body {
     .admin-top-actions {
         justify-content: center;
     }
+
+    .lang-btn {
+        padding: 4px 6px;
+        font-size: 0.75rem;
+    }
+
+    .diff-chip {
+        padding: 6px 10px;
+        font-size: 0.8rem;
+    }
 }