Initial commit: modern React video player library

Add all source files for a feature-rich, reusable video player built with React, TypeScript, and Vite. Includes core components, context, hooks, utilities, styles, demo app, and configuration files.

src/components/controls/ControlButton.css

@@ -0,0 +1,55 @@
+.control-button {
+  background: none;
+  border: none;
+  color: var(--player-text);
+  cursor: pointer;
+  padding: var(--player-spacing-sm);
+  display: inline-flex;
+  align-items: center;
+  justify-content: center;
+  border-radius: var(--player-radius-sm);
+  transition: all var(--player-transition-fast) ease;
+  position: relative;
+}
+
+.control-button:hover {
+  background-color: rgba(255, 255, 255, 0.1);
+  transform: scale(1.05);
+}
+
+.control-button:active {
+  transform: scale(0.95);
+}
+
+.control-button:focus-visible {
+  outline: 2px solid var(--player-primary);
+  outline-offset: 2px;
+}
+
+.control-button:disabled {
+  opacity: 0.5;
+  cursor: not-allowed;
+}
+
+.control-button:disabled:hover {
+  background-color: transparent;
+  transform: none;
+}
+
+/* Icon sizing */
+.control-button svg {
+  width: var(--player-icon-md);
+  height: var(--player-icon-md);
+  pointer-events: none;
+}
+
+@media (max-width: 640px) {
+  .control-button {
+    padding: var(--player-spacing-xs);
+  }
+
+  .control-button svg {
+    width: var(--player-icon-sm);
+    height: var(--player-icon-sm);
+  }
+}