feat: implement initial UI structure and multi-language support for downloader interface

src/style.css

@@ -775,3 +775,127 @@ input[type="text"]:focus {
     gap: 14px;
   }
 }
+
+/* Premium Language Switcher Selector */
+.language-selector-wrapper {
+  display: flex;
+  align-items: center;
+  margin-right: 8px;
+  height: 100%;
+}
+
+.language-select {
+  background: rgba(23, 20, 38, 0.7);
+  color: #dcd7eb;
+  border: 1px solid rgba(255, 255, 255, 0.12);
+  border-radius: 8px;
+  padding: 4px 26px 4px 8px;
+  font-size: 0.8rem;
+  font-weight: 500;
+  cursor: pointer;
+  outline: none;
+  font-family: inherit;
+  backdrop-filter: blur(10px);
+  -webkit-backdrop-filter: blur(10px);
+  transition: all 0.25s ease;
+  appearance: none;
+  -webkit-appearance: none;
+  -moz-appearance: none;
+  background-image: url("data:image/svg+xml;charset=UTF-8,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='12' viewBox='0 0 24 24' fill='none' stroke='%23ff0080' stroke-width='3' stroke-linecap='round' stroke-linejoin='round'%3E%3Cpolyline points='6 9 12 15 18 9'%3E%3C/polyline%3E%3C/svg%3E");
+  background-repeat: no-repeat;
+  background-position: right 8px center;
+  background-size: 10px;
+}
+
+.language-select:hover {
+  background: rgba(23, 20, 38, 0.9);
+  border-color: rgba(255, 0, 128, 0.5);
+  box-shadow: 0 0 10px rgba(255, 0, 128, 0.2);
+}
+
+.language-select option {
+  background: #171426;
+  color: #fff;
+}
+
+/* RTL (Right to Left) Styles for Arabic Support */
+html[dir="rtl"] {
+  direction: rtl;
+}
+
+html[dir="rtl"] * {
+  text-align: right;
+}
+
+html[dir="rtl"] .text-center, 
+html[dir="rtl"] .text-center * {
+  text-align: center;
+}
+
+html[dir="rtl"] .custom-titlebar {
+  flex-direction: row-reverse;
+}
+
+html[dir="rtl"] .titlebar-drag {
+  padding-right: 16px;
+  padding-left: 0;
+  flex-direction: row;
+}
+
+html[dir="rtl"] .language-selector-wrapper {
+  margin-right: 0;
+  margin-left: 8px;
+}
+
+html[dir="rtl"] .language-select {
+  padding: 4px 8px 4px 26px;
+  background-position: left 8px center;
+}
+
+html[dir="rtl"] .back-button {
+  flex-direction: row;
+  gap: 8px;
+}
+
+html[dir="rtl"] .back-button:hover {
+  transform: translateX(2px);
+}
+
+html[dir="rtl"] .back-chevron {
+  transform: rotate(180deg);
+}
+
+html[dir="rtl"] .track-item {
+  flex-direction: row;
+}
+
+html[dir="rtl"] .track-details {
+  text-align: right;
+}
+
+html[dir="rtl"] .track-details h4, 
+html[dir="rtl"] .track-details p, 
+html[dir="rtl"] .track-details span {
+  text-align: right;
+}
+
+html[dir="rtl"] .progress-panel .subtext {
+  text-align: right;
+}
+
+html[dir="rtl"] .option-row {
+  flex-direction: row;
+}
+
+html[dir="rtl"] .format-btn {
+  flex-direction: row;
+}
+
+html[dir="rtl"] .quality-pills {
+  flex-direction: row;
+}
+
+html[dir="rtl"] .error-card {
+  flex-direction: row;
+}
+