/* Frontiers in Business and AI — journal frontend */
/* 修改版：强化导航栏、下拉菜单、用户菜单的视觉与动态交互 */

:root {
  --fbai-navy: #123f63;
  --fbai-blue: #1e6292;
  --fbai-sky: #2f86bd;
  --fbai-ink: #203040;
  --fbai-muted: #667684;
  --fbai-border: #dce5ec;
  --fbai-surface: #f5f8fb;
  --fbai-ease: cubic-bezier(.22, .61, .36, 1);
}

body {
  color: var(--fbai-ink);
  background: #f6f8fa;
}

/* =========================================================
   1. 顶部导航栏 —— 毛玻璃 + 吸顶 + 流光装饰线
   ========================================================= */

.pkp_structure_head {
  position: sticky;
  top: 0;
  z-index: 900;
  background: rgba(255, 255, 255, .94);
  -webkit-backdrop-filter: saturate(180%) blur(14px);
  backdrop-filter: saturate(180%) blur(14px);
  border-bottom: 1px solid var(--fbai-border);
  box-shadow: 0 4px 16px rgba(18, 63, 99, .08);
  transition: box-shadow .35s var(--fbai-ease),
              background-color .35s var(--fbai-ease);
}

/* 顶部一条缓慢流动的彩色光带 */
.pkp_structure_head::before {
  content: "";
  display: block;
  height: 3px;
  background: linear-gradient(
    90deg,
    var(--fbai-navy) 0%,
    var(--fbai-sky) 35%,
    #7fc9f0 50%,
    var(--fbai-sky) 65%,
    var(--fbai-navy) 100%
  );
  background-size: 200% 100%;
  animation: fbai-topline 14s linear infinite;
}

@keyframes fbai-topline {
  from { background-position: 0% 50%; }
  to   { background-position: 200% 50%; }
}

/* 往下滚动时，导航栏阴影加深（支持的浏览器才生效） */
@supports (animation-timeline: scroll()) {
  .pkp_structure_head {
    animation: fbai-header-lift linear both;
    animation-duration: auto;
    animation-timeline: scroll(root);
    animation-range: 0 140px;
  }
}

@keyframes fbai-header-lift {
  to {
    box-shadow: 0 10px 30px rgba(18, 63, 99, .16);
    background-color: rgba(255, 255, 255, .98);
  }
}

/* 站点名称 */
.pkp_site_name .is_text {
  color: var(--fbai-navy);
  transition: color .25s var(--fbai-ease);
}

.pkp_site_name a:hover,
.pkp_site_name a:hover .is_text {
  color: var(--fbai-blue);
}

/* =========================================================
   2. 主导航 —— 胶囊悬停 + 渐变下划线 + 下拉动画
   ========================================================= */

.pkp_navigation_primary > li > a {
  position: relative;
  display: block;
  padding: 12px 16px;
  color: var(--fbai-navy);
  font-weight: 600;
  text-decoration: none;
  border-radius: 8px;
  transition: color .25s var(--fbai-ease),
              background-color .25s var(--fbai-ease);
}

/* 渐变下划线（默认收起，悬停/当前项展开） */
.pkp_navigation_primary > li > a::after {
  content: "";
  position: absolute;
  left: 16px;
  right: 16px;
  bottom: 6px;
  height: 2px;
  border-radius: 2px;
  background: linear-gradient(90deg, var(--fbai-sky), var(--fbai-blue));
  transform: scaleX(0);
  transform-origin: center;
  transition: transform .3s var(--fbai-ease);
}

.pkp_navigation_primary > li > a:hover,
.pkp_navigation_primary > li > a:focus-visible {
  color: var(--fbai-blue);
  background: rgba(47, 134, 189, .09);
}

.pkp_navigation_primary > li > a:hover::after,
.pkp_navigation_primary > li > a:focus-visible::after,
.pkp_navigation_primary > li.current > a::after,
.pkp_navigation_primary > li > a.active::after {
  transform: scaleX(1);
}

.pkp_navigation_primary > li.current > a,
.pkp_navigation_primary > li > a.active {
  color: var(--fbai-blue);
}

/* 有下拉菜单的项，右侧加一个小箭头 */
.pkp_navigation_primary > li:has(> ul) > a {
  padding-right: 32px;
}

.pkp_navigation_primary > li:has(> ul) > a::before {
  content: "";
  position: absolute;
  top: calc(50% - 5px);
  right: 14px;
  width: 6px;
  height: 6px;
  border-right: 1.8px solid currentColor;
  border-bottom: 1.8px solid currentColor;
  transform: rotate(45deg);
  transform-origin: center;
  transition: transform .3s var(--fbai-ease),
              top .3s var(--fbai-ease);
}

.pkp_navigation_primary > li:has(> ul):hover > a::before,
.pkp_navigation_primary > li:has(> ul):focus-within > a::before {
  top: calc(50% - 3px);
  transform: rotate(225deg);
}

/* ---------- 下拉菜单 ---------- */

.pkp_navigation_primary li {
  position: relative;
}

.pkp_navigation_primary ul {
  position: absolute;
  top: calc(100% + 8px);
  left: 0;
  z-index: 1200;
  display: block !important;
  min-width: 220px;
  margin: 0;
  padding: 8px;
  list-style: none;
  background: #ffffff;
  border: 1px solid var(--fbai-border);
  border-radius: 12px;
  box-shadow: 0 18px 38px rgba(18, 63, 99, .14);
  opacity: 0;
  visibility: hidden;
  transform: translateY(10px) scale(.98);
  transform-origin: top left;
  pointer-events: none;
  transition: opacity .22s var(--fbai-ease),
              transform .22s var(--fbai-ease),
              visibility .22s;
}

/* 下拉框上的小三角 */
.pkp_navigation_primary ul::before {
  content: "";
  position: absolute;
  top: -6px;
  left: 22px;
  width: 10px;
  height: 10px;
  background: #ffffff;
  border-left: 1px solid var(--fbai-border);
  border-top: 1px solid var(--fbai-border);
  transform: rotate(45deg);
}

.pkp_navigation_primary li:hover > ul,
.pkp_navigation_primary li:focus-within > ul {
  opacity: 1;
  visibility: visible;
  transform: translateY(0) scale(1);
  pointer-events: auto;
}

.pkp_navigation_primary ul li {
  display: block;
  width: 100%;
}

.pkp_navigation_primary ul a {
  display: block;
  padding: 9px 14px;
  color: var(--fbai-ink);
  font-size: .95rem;
  font-weight: 500;
  text-decoration: none;
  border-radius: 8px;
  transition: background-color .18s ease,
              color .18s ease,
              padding-left .2s var(--fbai-ease);
}

.pkp_navigation_primary ul a:hover,
.pkp_navigation_primary ul a:focus-visible {
  color: var(--fbai-blue);
  background: var(--fbai-surface);
  padding-left: 20px;
}

/* =========================================================
   3. 用户导航（登录 / 注册 / 我的账户）—— 圆角胶囊按钮
   ========================================================= */

.pkp_navigation_user {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 8px;
  margin: 0;
  padding: 0;
  list-style: none;
}

.pkp_navigation_user > li {
  position: relative;
}

.pkp_navigation_user > li > a {
  display: inline-block;
  padding: 8px 16px;
  color: var(--fbai-blue);
  font-size: .9rem;
  font-weight: 600;
  background: #ffffff;
  border: 1px solid var(--fbai-border);
  border-radius: 999px;
  text-decoration: none;
  transition: color .25s var(--fbai-ease),
              background-color .25s var(--fbai-ease),
              border-color .25s var(--fbai-ease),
              transform .25s var(--fbai-ease),
              box-shadow .25s var(--fbai-ease);
}

.pkp_navigation_user > li > a:hover,
.pkp_navigation_user > li > a:focus-visible {
  color: #ffffff;
  background: var(--fbai-blue);
  border-color: var(--fbai-blue);
  transform: translateY(-1px);
  box-shadow: 0 6px 16px rgba(30, 98, 146, .28);
}

/* 用户菜单里的下拉 */
.pkp_navigation_user ul {
  position: absolute;
  top: calc(100% + 10px);
  right: 0;
  left: auto;
  z-index: 1200;
  display: block !important;
  min-width: 200px;
  margin: 0;
  padding: 8px;
  list-style: none;
  background: #ffffff;
  border: 1px solid var(--fbai-border);
  border-radius: 12px;
  box-shadow: 0 18px 38px rgba(18, 63, 99, .14);
  opacity: 0;
  visibility: hidden;
  transform: translateY(10px);
  pointer-events: none;
  transition: opacity .22s var(--fbai-ease),
              transform .22s var(--fbai-ease),
              visibility .22s;
}

.pkp_navigation_user li:hover > ul,
.pkp_navigation_user li:focus-within > ul {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
  pointer-events: auto;
}

.pkp_navigation_user ul a {
  display: block;
  padding: 9px 14px;
  color: var(--fbai-ink);
  border-radius: 8px;
  text-decoration: none;
  transition: background-color .18s ease, color .18s ease;
}

.pkp_navigation_user ul a:hover {
  color: var(--fbai-blue);
  background: var(--fbai-surface);
}

/* =========================================================
   4. 搜索框
   ========================================================= */

.pkp_search input[type="text"],
.pkp_search input[type="search"] {
  height: 36px;
  padding: 0 16px;
  color: var(--fbai-ink);
  font-size: .92rem;
  background: var(--fbai-surface);
  border: 1px solid var(--fbai-border);
  border-radius: 999px;
  transition: background-color .25s var(--fbai-ease),
              border-color .25s var(--fbai-ease),
              box-shadow .25s var(--fbai-ease);
}

.pkp_search input[type="text"]:focus,
.pkp_search input[type="search"]:focus {
  background: #ffffff;
  border-color: var(--fbai-sky);
  box-shadow: 0 0 0 4px rgba(47, 134, 189, .14);
  outline: none;
}

/* =========================================================
   5. 内容区
   ========================================================= */

.pkp_structure_content {
  max-width: 1240px;
}

.pkp_structure_main {
  background: #ffffff;
  border-radius: 12px;
  box-shadow: 0 8px 26px rgba(18, 63, 99, .07);
}

.page_index_journal {
  display: grid;
  position: relative;
  grid-template-columns: 200px minmax(0, 1fr);
  column-gap: 30px;
}

.page_index_journal .homepage_image {
  grid-column: 1;
  grid-row: 1;
  width: 200px;
  margin: 0 0 24px;
}

.page_index_journal .homepage_image img {
  display: block;
  width: 100%;
  height: auto;
  border-radius: 8px;
  box-shadow: 0 10px 24px rgba(18, 63, 99, .15);
}

.page_index_journal .homepage_about {
  grid-column: 2;
  grid-row: 1;
  min-height: 280px;
  margin: 0;
  padding: 0;
}

.page_index_journal .homepage_about h2,
.page_index_journal .current_issue h2 {
  color: var(--fbai-navy);
  line-height: 1.25;
}

.page_index_journal .homepage_about p {
  color: #3f4f5e;
  line-height: 1.72;
}

.page_index_journal .additional_content {
  grid-column: 1 / -1;
  grid-row: 3;
  margin: 32px 0;
}

.page_index_journal .cmp_announcements {
  grid-column: 1 / -1;
  grid-row: 2;
}

.fbai-facts {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 14px;
  margin: 0;
}

.fbai-fact {
  padding: 18px;
  background: var(--fbai-surface);
  border: 1px solid var(--fbai-border);
  border-radius: 10px;
}

.fbai-fact strong {
  display: block;
  margin-bottom: 5px;
  color: var(--fbai-navy);
}

.fbai-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin: 18px 0 0;
}

.fbai-actions a {
  display: inline-block;
  padding: 10px 15px;
  color: #ffffff;
  background: var(--fbai-blue);
  border: 1px solid var(--fbai-blue);
  border-radius: 7px;
  font-weight: 600;
  text-decoration: none;
}

.fbai-actions a:nth-child(n + 2) {
  color: var(--fbai-blue);
  background: #ffffff;
}

.page_index_journal .current_issue {
  grid-column: 1 / -1;
  grid-row: 4;
  margin-top: 36px;
  padding-top: 32px;
  border-top: 1px solid var(--fbai-border);
}

.current_issue .obj_issue_toc > .heading {
  display: grid;
  grid-template-columns: 160px 1fr;
  gap: 24px;
  align-items: start;
  padding-bottom: 26px;
}

.current_issue .obj_issue_toc > .heading .cover {
  grid-column: 1;
  grid-row: 1 / span 2;
  float: none !important;
  width: 160px;
}

.current_issue .obj_issue_toc > .heading .description {
  grid-column: 2;
  grid-row: 1;
  width: auto !important;
  margin-left: 0;
}

.current_issue .obj_issue_toc > .heading .published {
  grid-column: 2;
  grid-row: 2;
  margin-left: 0;
}

.current_issue .cmp_article_list {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 18px;
}

.current_issue .cmp_article_list > li {
  margin: 0;
  padding: 0;
  border: 0;
}

.current_issue .obj_article_summary {
  position: relative;
  min-height: 190px;
  height: 100%;
  padding: 20px 20px 18px 128px;
  background: #ffffff;
  border: 1px solid var(--fbai-border);
  border-radius: 10px;
  box-shadow: 0 6px 18px rgba(18, 63, 99, .06);
}

.current_issue .obj_article_summary > .cover {
  position: absolute;
  top: 20px;
  left: 20px;
  width: 88px;
  margin: 0;
}

.current_issue .obj_article_summary > .cover img {
  width: 88px;
  height: 124px;
  object-fit: cover;
  border-radius: 4px;
}

.current_issue .obj_article_summary .title {
  margin: 0 0 10px;
  font-size: 1rem;
  line-height: 1.45;
}

.current_issue .obj_article_summary .title a {
  color: var(--fbai-navy);
}

.current_issue .obj_article_summary .meta {
  color: var(--fbai-muted);
  font-size: 0.9rem;
}

.current_issue .galleys_links {
  margin-top: 14px;
}

.obj_galley_link {
  border-radius: 6px;
}

.pkp_structure_sidebar .pkp_block {
  margin-bottom: 18px;
  padding: 18px;
  background: #ffffff;
  border: 1px solid var(--fbai-border);
  border-radius: 10px;
}

.pkp_structure_sidebar .title {
  color: var(--fbai-navy);
}

.pkp_structure_footer_wrapper {
  color: rgba(255, 255, 255, 0.9);
  background: var(--fbai-navy);
}

.pkp_structure_footer_wrapper a,
.pkp_structure_footer_wrapper p {
  color: rgba(255, 255, 255, 0.9);
}

.pkp_page_static_page .page,
.pkp_page_about .page,
.pkp_page_information .page {
  line-height: 1.72;
}

.pkp_page_static_page .page h2,
.pkp_page_static_page .page h3,
.pkp_page_about .page h2,
.pkp_page_about .page h3,
.pkp_page_information .page h2,
.pkp_page_information .page h3 {
  color: var(--fbai-navy);
}

.pkp_page_APC.pkp_op_index .table-bordered {
  width: 100%;
  border: 1px solid var(--fbai-border);
  border-collapse: collapse;
}

.pkp_page_APC.pkp_op_index .table-bordered th,
.pkp_page_APC.pkp_op_index .table-bordered td {
  padding: 10px;
  border: 1px solid var(--fbai-border);
  text-align: center;
  vertical-align: middle;
}

.pkp_page_APC.pkp_op_index .table-striped tbody tr:nth-of-type(odd) {
  background: var(--fbai-surface);
}

/* =========================================================
   6. 响应式
   ========================================================= */

@media (min-width: 993px) {
  .pkp_navigation_primary {
    display: flex;
    align-items: center;
    flex-wrap: wrap;
    gap: 2px;
    margin: 0;
    padding: 0;
    list-style: none;
  }

  .pkp_navigation_primary_wrapper {
    display: flex;
    align-items: center;
    justify-content: space-between;
    flex-wrap: wrap;
    gap: 16px;
  }
}

@media (max-width: 992px) {
  /* 移动端：下拉改为内嵌展开，去掉浮层效果 */
  .pkp_navigation_primary > li > a::after {
    display: none;
  }

  .pkp_navigation_primary > li:has(> ul) > a::before {
    display: none;
  }

  .pkp_navigation_primary ul {
    position: static;
    display: block !important;
    min-width: 0;
    margin: 2px 0 6px 14px;
    padding: 0 0 0 12px;
    background: transparent;
    border: 0;
    border-left: 2px solid var(--fbai-border);
    border-radius: 0;
    box-shadow: none;
    opacity: 1;
    visibility: visible;
    transform: none;
    pointer-events: auto;
  }

  .pkp_navigation_primary ul::before {
    display: none;
  }

  .pkp_navigation_primary ul a {
    padding: 7px 10px;
    font-size: .9rem;
  }

  .pkp_navigation_user {
    justify-content: flex-start;
  }
}

@media (max-width: 900px) {
  .fbai-facts,
  .current_issue .cmp_article_list {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 768px) {
  .pkp_structure_main {
    border-radius: 0;
    box-shadow: none;
  }

  .page_index_journal .homepage_image {
    grid-column: 1;
    grid-row: 1;
    width: min(200px, 70vw);
    margin: 0 auto 28px;
  }

  .page_index_journal .homepage_about {
    grid-column: 1;
    grid-row: 2;
    min-height: 0;
  }

  .page_index_journal {
    grid-template-columns: 1fr;
  }

  .page_index_journal .cmp_announcements {
    grid-row: 3;
  }

  .page_index_journal .additional_content {
    grid-row: 4;
  }

  .page_index_journal .current_issue {
    grid-row: 5;
  }

  .current_issue .obj_issue_toc > .heading {
    grid-template-columns: 1fr;
  }

  .current_issue .obj_issue_toc > .heading .cover {
    grid-column: 1;
    grid-row: 1;
    width: min(180px, 70vw);
  }

  .current_issue .obj_issue_toc > .heading .description {
    grid-column: 1;
    grid-row: 2;
  }

  .current_issue .obj_issue_toc > .heading .published {
    grid-column: 1;
    grid-row: 3;
  }

  .current_issue .obj_article_summary {
    min-height: 0;
    padding-left: 20px;
  }

  .current_issue .obj_article_summary > .cover {
    position: static;
    width: 76px;
    margin: 0 0 14px;
  }

  .current_issue .obj_article_summary > .cover img {
    width: 76px;
    height: auto;
  }
}

/* =========================================================
   7. 无障碍 / 减少动态效果
   ========================================================= */

.pkp_structure_head a:focus-visible,
.pkp_structure_head button:focus-visible,
.pkp_navigation_primary a:focus-visible,
.pkp_navigation_user a:focus-visible {
  outline: 2px solid var(--fbai-sky);
  outline-offset: 2px;
}

@media (prefers-reduced-motion: reduce) {
  .pkp_structure_head,
  .pkp_structure_head::before,
  .pkp_structure_head *,
  .pkp_navigation_primary *,
  .pkp_navigation_user * {
    animation: none !important;
    transition-duration: .01ms !important;
  }
}