fix: align lesson export action to the top right

projects/xiaoshu-admin/src/app/pages/lesson-records.component.scss

@@ -4,3 +4,5 @@
 .transfer-scope{border:0;padding:0;margin:0;min-width:0}.transfer-scope legend,.coach-picker>label{font-size:13px;font-weight:600;color:#5d7168;margin-bottom:8px}.transfer-scope label{display:flex;align-items:center;gap:8px;font-size:13px;margin-bottom:10px;cursor:pointer}.transfer-scope input{width:17px;min-height:17px;margin:0;accent-color:#197958}.coach-picker{min-width:0}.coach-picker>label{display:block}.coach-picker input{color-scheme:light;background:#fff}.coach-results{margin-top:8px;max-height:240px;overflow:auto;background:#fff;border:1px solid #ccdcd4;border-radius:10px;box-shadow:0 6px 18px #234d3510}.coach-results:empty{display:none}.transfer-panel .coach-results button{display:flex;align-items:center;gap:10px;width:100%;margin:0;padding:12px 14px;border:0;border-bottom:1px solid #eef3f0;background:#fff;color:#233d35;text-align:left;font:inherit;border-radius:0}.coach-results button:last-child{border-bottom:0}.transfer-panel .coach-results button:hover,.transfer-panel .coach-results button.keyboard-active,.transfer-panel .coach-results button[aria-selected=true]{background:#e6f3ed;color:#146c50}.coach-results small{font-size:12px;color:#697e75;margin-left:auto;white-space:nowrap}.coach-check{color:#197958;font-weight:700}.coach-hint{display:block;font-size:12px;color:#697e75;line-height:1.6;margin-top:7px}.coach-empty{padding:12px;margin:8px 0 0;background:#fff;border:1px solid #dfe8e4;border-radius:8px;font-size:13px;color:#697e75}
 
 .lesson-drawer{overscroll-behavior:contain}.coach-results{max-height:min(240px,35dvh);overscroll-behavior:contain}
+
+.lesson-history>.page-header{display:grid;grid-template-columns:minmax(0,1fr) auto;align-items:start;gap:16px}.lesson-history>.page-header>div{min-width:0}.lesson-history>.page-header>.ui-button{justify-self:end}