*{box-sizing:border-box}body{margin:0;background:#f5f6f8;color:#222;font-family:-apple-system,BlinkMacSystemFont,"Segoe UI","PingFang SC",sans-serif}header{background:#fff;padding:14px 18px;display:flex;justify-content:space-between;align-items:center;position:sticky;top:0;z-index:2;box-shadow:0 1px 8px #ddd}nav a,header a{margin-left:14px;color:#333;text-decoration:none}main{max-width:1000px;margin:20px auto;padding:0 14px}.card{background:#fff;border-radius:14px;padding:18px;margin-bottom:16px;box-shadow:0 2px 12px rgba(0,0,0,.05)}.login{min-height:100vh;display:grid;place-items:center;padding:20px}.login .card{width:min(420px,100%);text-align:center}input,select,textarea,button{width:100%;padding:12px;margin:6px 0;border:1px solid #ddd;border-radius:10px;font-size:16px}textarea{min-height:100px}.btn,button{background:#222;color:#fff;border:0;text-decoration:none;display:block;text-align:center;cursor:pointer}.wechat{background:#07c160}.grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(260px,1fr));gap:14px}.task{display:flex;justify-content:space-between;gap:8px;padding:12px;margin-top:8px;background:#f6f7f8;border-radius:10px;cursor:pointer}.task.done{background:#eaf8ee;text-decoration:line-through}.row{display:flex;justify-content:space-between;gap:10px;align-items:center;border-bottom:1px solid #eee;padding:12px 0}.row form{display:flex;gap:5px}.row button{width:auto;margin:0;padding:8px 12px}.muted{color:#777}.error{background:#fff0f0;color:#c00;padding:10px;border-radius:8px}.success{background:#eaf8ee;color:#087b35;padding:14px;border-radius:10px;margin-top:14px}.progress{font-size:24px;font-weight:700;margin:15px 0}@media(max-width:600px){header{font-size:14px}nav a{margin-left:7px}.row{align-items:flex-start;flex-direction:column}.row form,.row select{width:100%}}

/* ===== 页面版权 ===== */
body::after {
  content: "版权所有 Copyright © 2026 YTogether";
  display: block;
  text-align: center;
  font-size: 12px;
  color: #a8aebd;
  letter-spacing: 0.3px;
  padding: 22px 16px 18px;
  margin-top: 20px;
  border-top: 1px solid #e8ecf3;
  clear: both;
}