✨feature: Split styles and JavaScript to separate files, rework layout

style.css

@@ -0,0 +1,99 @@
+body {
+  background: #0f1420;
+  color: #e9eef8;
+  font-family: system-ui, Arial, sans-serif;
+  margin: 0;
+}
+
+header {
+  align-items: center;
+  background: #121a2a;
+  border-bottom: 1px solid #27324a;
+  display: flex;
+  justify-content: space-between;
+  padding: 12px 16px;
+}
+
+h1 {
+  font-size: 18px;
+  margin: 0;
+}
+
+main {
+  display: grid;
+  gap: 16px;
+  grid-template-columns: 300px 1fr;
+  padding: 16px;
+}
+
+.panel {
+  background: #111827;
+  border: 1px solid #27324a;
+  border-radius: 8px;
+
+  h2 {
+    color: #a3b5d9;
+    font-size: 14px;
+    margin: 0;
+    padding: 12px 12px 0;
+  }
+
+  .content { padding: 12px; }
+
+  &.log { grid-column: 1 / span 2; }
+}
+
+#log {
+  background: #0b1020;
+  color: #e9eef8;
+  max-height: 60vh;
+  min-height: 360px;
+  overflow: auto;
+  white-space: pre-wrap;
+}
+
+.row {
+  display: flex;
+  flex-wrap: wrap;
+  gap: 8px;
+}
+
+button {
+  background: #1f2a44;
+  border: 1px solid #2c3a5e;
+  border-radius: 6px;
+  color: #e9eef8;
+  cursor: pointer;
+  padding: 8px 10px;
+
+  &:hover { background: #263356; }
+
+  &:disabled {
+    cursor: not-allowed;
+    opacity: 0.5;
+  }
+}
+
+.hidden {
+  display: none;
+  visibility: hidden;
+}
+
+.muted { color: #a3b5d9; }
+
+.sep {
+  background: #27324a;
+  height: 1px;
+  margin: 8px 0;
+}
+
+.mono { font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace; }
+
+.kv {
+  display: flex;
+  gap: 8px;
+  justify-content: space-between;
+  margin: 2px 0;
+
+  .label { color: #a3b5d9; }
+}