* { box-sizing: border-box; }
html, body { height: 100%; overflow: hidden; }
body { margin: 0; font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, 'Noto Sans', 'PingFang SC', 'Microsoft YaHei', sans-serif; color: #333; background: #f5f5f5; }
.container { max-width: 1200px; margin: 0 auto; padding: 16px; }
.container.fixed { width: 1200px; height: 700px; display: grid; grid-template-rows: auto 1fr auto; }
header { display: flex; align-items: baseline; justify-content: space-between; margin-bottom: 12px; }
header h1 { margin: 0; font-size: 22px; }
.status span { margin-left: 16px; font-size: 14px; color: #555; }
main { display: grid; grid-template-columns: 320px 1fr; gap: 16px; min-height: 0; overflow: hidden; }
.panel { background: #fff; border-radius: 8px; padding: 12px; border: 1px solid #ddd; min-height: 0; overflow: auto; }
.panel h3 { margin: 0 0 8px; font-size: 16px; }
.panel ul { list-style: none; padding: 0; margin: 0; }
.panel li { padding: 8px 10px; margin: 6px 0; background: #f0f0f0; border-radius: 6px; cursor: pointer; }
.panel li:hover { background: #e2e2e2; }
.chat { display: flex; flex-direction: column; background: #fff; border: 1px solid #ddd; border-radius: 8px; padding: 12px; min-height: 0; }
.messages { flex: 1; overflow: auto; height: auto; padding-right: 6px; }
.msg { border-bottom: 1px dashed #eee; padding: 8px 0; }
.msg .who { font-size: 12px; color: #666; margin-bottom: 4px; }
.msg .body p { margin: 2px 0; line-height: 1.4; }
.composer { display: flex; gap: 8px; margin-top: 10px; }
.composer input { flex: 1; padding: 10px; border: 1px solid #ccc; border-radius: 6px; }
.composer button { padding: 10px 16px; background: #4682B4; border: none; color: #fff; border-radius: 6px; cursor: pointer; }
.composer button:hover { background: #3a6d95; }
footer { margin-top: 12px; text-align: right; }
footer button { padding: 8px 14px; border: 1px solid #ccc; background: #fff; border-radius: 6px; cursor: pointer; }
footer button:hover { background: #f0f0f0; }