/* study999-logged-mobile-header-v1
   手机版登录后顶部布局与未登录页统一。
*/

@media screen and (max-width: 720px) {

  /* 登录后：网站顶部整体间距与未登录状态一致。 */
  body.study999-logged-nav > header {
    box-sizing: border-box !important;
    width: 100% !important;
    max-width: 100% !important;

    padding: 3px 8px !important;
    gap: 3px !important;

    flex-wrap: wrap !important;
    align-items: center !important;
    min-width: 0 !important;
  }

  /* Logo：与未登录状态相同的最大高度。 */
  body.study999-logged-nav > header img {
    width: auto !important;
    height: auto !important;

    max-width: 48px !important;
    max-height: 42px !important;

    object-fit: contain !important;
    flex-shrink: 0 !important;
  }

  /* 网站名：与未登录状态使用同一字号。 */
  body.study999-logged-nav
  > header .study999-site-title {
    font-size: clamp(16px, 4.5vw, 22px) !important;
    line-height: 1.15 !important;

    min-width: 0 !important;
    margin: 0 !important;
    padding: 0 !important;
  }

  /* 登录后的导航区域紧凑显示。 */
  body.study999-logged-nav > header > nav {
    box-sizing: border-box !important;
    min-width: 0 !important;
    max-width: 100% !important;

    margin: 0 !important;
    padding: 0 !important;
  }

  /* 四个导航按钮：统一为未登录页的32px高度。 */
  body.study999-logged-nav
  > header nav button:not([hidden]) {
    box-sizing: border-box !important;

    height: 32px !important;
    min-height: 32px !important;
    max-height: 32px !important;

    min-width: 0 !important;
    margin: 0 !important;
    padding: 1px 2px !important;

    gap: 3px !important;

    font-size: clamp(10px, 2.7vw, 12px) !important;
    line-height: 1.1 !important;
    white-space: nowrap !important;

    align-items: center !important;
    justify-content: center !important;
  }

  /* 缩小按钮内图标，保留原有图标和配色。 */
  body.study999-logged-nav
  > header nav button svg {
    width: 13px !important;
    height: 13px !important;
    flex: 0 0 13px !important;
  }

  /* 防止按钮文字造成导航栏额外增高。 */
  body.study999-logged-nav
  > header nav button span {
    font-size: inherit !important;
    line-height: 1.1 !important;
    white-space: nowrap !important;
  }
}


/* study999-mobile-four-nav-v2 */

@media screen and (max-width: 720px) {

  /* Logo 和网站名占第一行；
     四个导航按钮完整占据第二行。 */
  body.study999-logged-nav > header > nav {
    display: block !important;
    flex: 0 0 100% !important;

    width: 100% !important;
    min-width: 0 !important;
    max-width: 100% !important;

    margin: 0 !important;
    padding: 0 !important;
  }

  /* 四个按钮始终横向并列。 */
  body.study999-logged-nav
  #study999-student-nav:not([hidden]) {
    display: grid !important;

    grid-template-columns:
      repeat(4, minmax(0, 1fr)) !important;

    grid-template-rows: 32px !important;

    width: 100% !important;
    min-width: 0 !important;
    max-width: none !important;

    gap: 4px !important;
    margin: 0 !important;
    padding: 0 !important;

    align-items: stretch !important;
  }

  /* 保持原有配色及图标，只压缩按钮布局。 */
  body.study999-logged-nav
  #study999-student-nav
  > button.study999-student-nav-btn {
    box-sizing: border-box !important;

    display: flex !important;
    flex-direction: row !important;

    align-items: center !important;
    justify-content: center !important;

    width: 100% !important;
    min-width: 0 !important;
    max-width: 100% !important;

    height: 32px !important;
    min-height: 32px !important;
    max-height: 32px !important;

    margin: 0 !important;
    padding: 2px 1px !important;
    gap: 3px !important;

    font-size: clamp(10px, 2.7vw, 12px) !important;
    line-height: 1.1 !important;
    white-space: nowrap !important;
  }

  /* 图标适当缩小，保证四个按钮放得下。 */
  body.study999-logged-nav
  #study999-student-nav
  > button.study999-student-nav-btn svg {
    width: 12px !important;
    height: 12px !important;
    flex: 0 0 12px !important;
  }

  body.study999-logged-nav
  #study999-student-nav
  > button.study999-student-nav-btn span {
    min-width: 0 !important;

    font-size: inherit !important;
    line-height: 1.1 !important;
    white-space: nowrap !important;
  }

}