:root {
  --accent: #2f6fed;
  --bg: #f5f6f8;
  --card-bg: #ffffff;
  --text: #1f2329;
  --muted: #6b7280;
  --border: #e5e7eb;
  --shadow: 0 1px 3px rgba(16,24,40,.06), 0 8px 24px rgba(16,24,40,.04);
  --radius: 12px;
}
* { box-sizing: border-box; }
html, body {
  margin: 0; padding: 0; background: var(--bg); color: var(--text);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Helvetica Neue", Arial, sans-serif;
  font-size: 14px; line-height: 1.6;
}

/* 顶部导航 */
.topnav { position: sticky; top: 0; z-index: 50; background: var(--card-bg); border-bottom: 1px solid var(--border); }
.topnav-inner { max-width: 1100px; margin: 0 auto; height: 60px; padding: 0 24px; display: flex; align-items: center; justify-content: space-between; }
.brand { font-size: 17px; font-weight: 700; letter-spacing: .5px; }
.topnav-actions { display: flex; gap: 8px; align-items: center; }
.user-tag { font-size: 13px; color: var(--muted); margin-right: 4px; }
.link-btn { border: 1px solid var(--border); background: #fff; color: var(--muted); padding: 6px 14px; border-radius: 8px; cursor: pointer; font-size: 13px; text-decoration: none; line-height: 1.2; }
.link-btn:hover { color: var(--accent); border-color: var(--accent); }

/* 主体 */
.main { max-width: 1100px; margin: 0 auto; padding: 36px 24px 24px; }
.cards { display: grid; grid-template-columns: repeat(2, 1fr); gap: 24px; margin-bottom: 36px; }
.card { background: var(--card-bg); border: 1px solid var(--border); border-radius: var(--radius); box-shadow: var(--shadow); padding: 28px 26px 22px; display: flex; flex-direction: column; min-height: 260px; }
.card-title { font-size: 19px; font-weight: 700; margin: 0 0 6px; }
.card-sub { color: var(--accent); font-size: 13px; font-weight: 600; margin: 0 0 14px; }
.card-desc { color: var(--muted); font-size: 13.5px; margin: 0 0 20px; flex: 1; }
.card-btn { align-self: flex-start; background: var(--accent); color: #fff; border: none; padding: 11px 22px; border-radius: 9px; font-size: 14px; font-weight: 600; cursor: pointer; text-decoration: none; }
.card-btn:hover { opacity: .9; }
.card-roles { margin-top: 14px; font-size: 12px; color: var(--muted); }
.card.placeholder { border-style: dashed; background: #fafbfc; align-items: center; justify-content: center; text-align: center; color: var(--muted); }

/* 通知 */
.section-title { font-size: 16px; font-weight: 700; margin: 0 0 14px; }
.notice-box { background: var(--card-bg); border: 1px solid var(--border); border-radius: var(--radius); box-shadow: var(--shadow); padding: 18px 22px; }
.notice-list { margin: 0; padding-left: 18px; }
.notice-list li { margin: 6px 0; }
.notice-empty { color: var(--muted); margin: 0; }

/* 页脚 */
.footer { max-width: 1100px; margin: 0 auto; padding: 28px 24px 40px; text-align: center; color: #9aa0a6; font-size: 12px; }

/* 弹窗 */
.modal-mask { position: fixed; inset: 0; background: rgba(16,24,40,.45); display: flex; align-items: center; justify-content: center; z-index: 100; padding: 20px; }
.modal-mask[hidden] { display: none; }
.modal { background: #fff; width: 100%; max-width: 520px; border-radius: var(--radius); box-shadow: 0 20px 60px rgba(16,24,40,.25); overflow: hidden; }
.modal-head { display: flex; align-items: center; justify-content: space-between; padding: 16px 20px; border-bottom: 1px solid var(--border); }
.modal-head h3 { margin: 0; font-size: 16px; }
.modal-close { border: none; background: transparent; font-size: 22px; line-height: 1; color: var(--muted); cursor: pointer; }
.modal-body { padding: 20px; font-size: 13.5px; white-space: pre-wrap; max-height: 60vh; overflow-y: auto; }

/* 登录页 */
.login-wrap { min-height: 100vh; display: flex; align-items: center; justify-content: center; padding: 20px; }
.login-card { background: var(--card-bg); border: 1px solid var(--border); border-radius: var(--radius); box-shadow: var(--shadow); padding: 36px 32px; width: 360px; }
.login-brand { font-size: 19px; font-weight: 700; text-align: center; }
.login-sub { text-align: center; color: var(--muted); font-size: 12px; margin: 6px 0 24px; }
.login-error { background: #fdecec; color: #c0392b; font-size: 13px; padding: 8px 12px; border-radius: 8px; margin-bottom: 14px; }
.login-input { width: 100%; padding: 11px 14px; margin-bottom: 14px; border: 1px solid var(--border); border-radius: 9px; font-size: 14px; }
.login-input:focus { outline: none; border-color: var(--accent); }
.login-btn { width: 100%; background: var(--accent); color: #fff; border: none; padding: 12px; border-radius: 9px; font-size: 15px; font-weight: 600; cursor: pointer; }
.login-btn:hover { opacity: .9; }

@media (max-width: 760px) { .cards { grid-template-columns: 1fr; } }