/* ============================================================
   SwimX — 顶栏 / 主体 / 页脚 / 分区标题
   ============================================================ */

/* 顶栏 */
.topbar {
  position: sticky; top: 0; z-index: 100;
  background: rgba(255,255,255,.94); backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border);
  padding: 0 24px; height: 56px;
  display: flex; align-items: center; justify-content: space-between;
}
.topbar-brand { display: flex; align-items: center; gap: 10px; }
.topbar-logo {
  width: 36px; height: 36px; border-radius: 50%;
  background: var(--p); display: flex; align-items: center; justify-content: center;
  color: #fff; font-size: 18px; font-weight: 900;
}
.topbar-name { font-size: 16px; font-weight: 800; }

.topbar-nav { display: flex; align-items: center; gap: 6px; }
.topbar-nav a {
  font-size: 13px; font-weight: 600; padding: 5px 12px; border-radius: 16px;
  color: var(--ts); transition: all .2s; white-space: nowrap;
}
.topbar-nav a:hover { background: var(--pghost); color: var(--pd); }
.topbar-nav a.nav-teach:hover { background: #D8F3DC; color: #2D6A4F; }
.topbar-nav a.nav-game:hover { background: var(--al); color: var(--ad); }
.topbar-nav a.nav-download:hover { background: #FFF0E0; color: #F97316; }
.topbar-nav a.nav-msg:hover { background: #E0F0FF; color: #4EA8DE; }

.back-btn {
  display: flex; align-items: center; gap: 6px;
  padding: 8px 16px; border-radius: 10px;
  border: 1.5px solid var(--border); background: #fff;
  font-size: 13px; font-weight: 700; color: var(--ts);
  cursor: pointer; transition: all .2s;
}
.back-btn:hover { border-color: var(--p); color: var(--p); }

/* 主体容器 */
.main { max-width: 840px; margin: 0 auto; padding: 0 20px 40px; }

/* 分区标题 */
.section { margin-top: 32px; }
.section-head { display: flex; align-items: center; gap: 12px; margin-bottom: 18px; }
.section-head .icon {
  width: 40px; height: 40px; border-radius: 12px;
  display: flex; align-items: center; justify-content: center; font-size: 20px;
}
.section-head .icon.teach { background: var(--pbg); color: var(--pd); }
.section-head .icon.game { background: var(--al); color: var(--ad); }
.section-head h2 { font-size: 20px; font-weight: 800; }
.section-head .badge {
  font-size: 11px; padding: 3px 10px; border-radius: 20px; font-weight: 700;
}

/* 页脚 */
.footer {
  text-align: center; padding: 30px 20px; color: var(--tl);
  font-size: 12px; border-top: 1px solid var(--border); margin-top: 40px;
}
.footer a { color: var(--p); font-weight: 600; }