:root {
      --primary: #0B3D91;
      --primary-dark: #072b67;
      --primary-soft: #eaf1fb;
      --ink: #172033;
      --muted: #637089;
      --line: #dfe5ee;
      --surface: #ffffff;
      --background: #f5f7fa;
      --success: #07855b;
      --warning: #d97706;
      --radius: 6px;
      --shadow: 0 12px 32px rgba(16, 34, 64, 0.08);
    }

    * {
      box-sizing: border-box;
    }

    html {
      scroll-behavior: smooth;
    }

    body {
      margin: 0;
      color: var(--ink);
      background: var(--background);
      font-family: "Microsoft YaHei", "PingFang SC", Arial, sans-serif;
      font-size: 15px;
      line-height: 1.7;
    }

    body,
    button,
    input,
    textarea {
      letter-spacing: 0;
    }

    img {
      display: block;
      max-width: 100%;
    }

    a {
      color: inherit;
      text-decoration: none;
    }

    button {
      font: inherit;
    }

    .container {
      width: min(1180px, calc(100% - 40px));
      margin: 0 auto;
    }

    .topbar {
      min-height: 36px;
      color: #dce8fb;
      background: var(--primary-dark);
      font-size: 12px;
    }

    .topbar .container {
      min-height: 36px;
      display: flex;
      align-items: center;
      justify-content: space-between;
      gap: 24px;
    }

    .topbar-links {
      display: flex;
      align-items: center;
      gap: 22px;
    }

    .topbar a:hover {
      color: #ffffff;
    }

    .header {
      position: sticky;
      top: 0;
      z-index: 100;
      background: rgba(255, 255, 255, 0.98);
      border-bottom: 1px solid var(--line);
      box-shadow: 0 4px 18px rgba(20, 35, 60, 0.04);
    }

    .header-inner {
      min-height: 76px;
      display: flex;
      align-items: center;
      gap: 28px;
    }

    .logo {
      min-width: 180px;
      display: inline-flex;
      align-items: center;
      gap: 10px;
      color: var(--primary);
      font-size: 18px;
      font-weight: 800;
      white-space: nowrap;
    }

    .logo img {
      width: 40px;
      height: 40px;
      object-fit: contain;
    }

    .main-nav {
      flex: 1;
      align-self: stretch;
    }

    .nav-list {
      height: 100%;
      display: flex;
      align-items: stretch;
      justify-content: center;
      gap: 2px;
      margin: 0;
      padding: 0;
      list-style: none;
    }

    .nav-item {
      position: relative;
      display: flex;
      align-items: center;
    }

    .nav-link {
      height: 100%;
      min-height: 76px;
      display: inline-flex;
      align-items: center;
      padding: 0 13px;
      border-bottom: 3px solid transparent;
      color: #26344d;
      font-size: 14px;
      font-weight: 700;
      white-space: nowrap;
    }

    .nav-link:hover,
    .nav-item:focus-within > .nav-link {
      color: var(--primary);
      border-bottom-color: var(--primary);
    }

    .has-arrow::after {
      width: 6px;
      height: 6px;
      margin: -4px 0 0 8px;
      border-right: 1.5px solid currentColor;
      border-bottom: 1.5px solid currentColor;
      content: "";
      transform: rotate(45deg);
    }

    .dropdown-panel,
    .mega-menu {
      position: absolute;
      top: 100%;
      z-index: 120;
      padding: 22px;
      visibility: hidden;
      background: var(--surface);
      border: 1px solid var(--line);
      border-top: 3px solid var(--primary);
      border-radius: 0 0 var(--radius) var(--radius);
      box-shadow: var(--shadow);
      opacity: 0;
      transform: translateY(8px);
      transition: opacity 0.18s ease, transform 0.18s ease, visibility 0.18s;
    }

    .dropdown-panel::before,
    .mega-menu::before {
      position: absolute;
      right: 0;
      bottom: 100%;
      left: 0;
      height: 10px;
      content: "";
    }

    .dropdown-panel {
      left: 0;
      width: 310px;
    }

    .mega-menu {
      left: 50%;
      width: min(720px, calc(100vw - 40px));
      transform: translate(-50%, 8px);
    }

    .nav-item:hover .dropdown-panel,
    .nav-item:focus-within .dropdown-panel {
      visibility: visible;
      opacity: 1;
      transform: translateY(0);
    }

    .nav-item:hover .mega-menu,
    .nav-item:focus-within .mega-menu {
      visibility: visible;
      opacity: 1;
      transform: translate(-50%, 0);
    }

    .panel-title {
      margin: 0 0 12px;
      color: #18243a;
      font-size: 14px;
    }

    .panel-list {
      display: grid;
      gap: 2px;
    }

    .panel-list a {
      display: flex;
      align-items: center;
      justify-content: space-between;
      gap: 10px;
      padding: 9px 10px;
      border-radius: 4px;
      color: #435069;
      font-size: 13px;
    }

    .panel-list a:hover {
      color: var(--primary);
      background: var(--primary-soft);
    }

    .panel-list small {
      flex: 0 0 auto;
      color: var(--muted);
    }

    .mega-grid {
      display: grid;
      grid-template-columns: minmax(0, 1.55fr) minmax(220px, 0.8fr);
      gap: 28px;
    }

    .mega-cards {
      display: grid;
      grid-template-columns: repeat(2, minmax(0, 1fr));
      gap: 8px;
    }

    .mega-card {
      min-width: 0;
      display: grid;
      grid-template-columns: auto 1fr;
      gap: 3px 9px;
      padding: 10px;
      border: 1px solid #e6eaf0;
      border-radius: 5px;
      color: #293750;
    }

    .mega-card:hover {
      border-color: #b9c9e4;
      background: var(--primary-soft);
    }

    .mega-card img {
      grid-row: 1 / span 2;
      width: 32px;
      height: 32px;
      object-fit: contain;
    }

    .mega-card strong,
    .mega-card small {
      min-width: 0;
      overflow: hidden;
      text-overflow: ellipsis;
    }

    .mega-card strong {
      font-size: 13px;
      white-space: nowrap;
    }

    .mega-card small {
      display: block;
      color: var(--muted);
      font-size: 11px;
      line-height: 1.45;
    }

    .mega-footer {
      display: inline-flex;
      align-items: center;
      margin-top: 13px;
      color: var(--primary);
      font-size: 13px;
      font-weight: 800;
    }

    .mega-footer::after {
      margin-left: 6px;
      content: "→";
    }

    .header-btns {
      display: flex;
      align-items: center;
      gap: 8px;
    }

    .member-btn,
    .open-btn {
      min-height: 38px;
      display: inline-flex;
      align-items: center;
      justify-content: center;
      padding: 0 15px;
      border: 1px solid var(--primary);
      border-radius: 4px;
      font-size: 13px;
      font-weight: 800;
      white-space: nowrap;
    }

    .member-btn {
      color: var(--primary);
      background: #ffffff;
    }

    .open-btn {
      color: #ffffff;
      background: var(--primary);
    }

    .member-btn:hover,
    .open-btn:hover {
      color: #ffffff;
      background: var(--primary-dark);
      border-color: var(--primary-dark);
    }

    .hamburger {
      width: 42px;
      height: 42px;
      display: none;
      position: relative;
      padding: 0;
      border: 1px solid var(--line);
      border-radius: 4px;
      background: #ffffff;
      cursor: pointer;
    }

    .hamburger span {
      position: absolute;
      left: 11px;
      width: 18px;
      height: 2px;
      background: var(--ink);
      transition: transform 0.2s ease, opacity 0.2s ease;
    }

    .hamburger span:nth-child(1) {
      top: 13px;
    }

    .hamburger span:nth-child(2) {
      top: 19px;
    }

    .hamburger span:nth-child(3) {
      top: 25px;
    }

    .hamburger.active span:nth-child(1) {
      top: 19px;
      transform: rotate(45deg);
    }

    .hamburger.active span:nth-child(2) {
      opacity: 0;
    }

    .hamburger.active span:nth-child(3) {
      top: 19px;
      transform: rotate(-45deg);
    }

    .drawer-overlay {
      position: fixed;
      inset: 0;
      z-index: 190;
      visibility: hidden;
      background: rgba(8, 18, 34, 0.52);
      opacity: 0;
      transition: opacity 0.2s ease, visibility 0.2s;
    }

    .drawer-overlay.open {
      visibility: visible;
      opacity: 1;
    }

    .mobile-drawer {
      position: fixed;
      top: 0;
      right: 0;
      z-index: 200;
      width: min(380px, 88vw);
      height: 100dvh;
      overflow-y: auto;
      background: #ffffff;
      box-shadow: -18px 0 50px rgba(8, 18, 34, 0.18);
      transform: translateX(105%);
      transition: transform 0.24s ease;
    }

    .mobile-drawer.open {
      transform: translateX(0);
    }

    .drawer-head {
      min-height: 68px;
      display: flex;
      align-items: center;
      gap: 10px;
      padding: 12px 18px;
      color: #ffffff;
      background: var(--primary);
    }

    .drawer-head > span {
      min-width: 0;
      flex: 1;
      font-weight: 800;
    }

    .drawer-head > a {
      padding: 6px 12px;
      border: 1px solid rgba(255, 255, 255, 0.55);
      border-radius: 4px;
      font-size: 13px;
    }

    .drawer-close {
      width: 36px;
      height: 36px;
      padding: 0;
      color: #ffffff;
      background: transparent;
      border: 0;
      font-size: 28px;
      line-height: 1;
      cursor: pointer;
    }

    .drawer-menu {
      padding: 12px 18px 28px;
    }

    .drawer-link,
    .drawer-toggle {
      width: 100%;
      min-height: 48px;
      display: flex;
      align-items: center;
      padding: 10px 4px;
      color: #26344d;
      background: transparent;
      border: 0;
      border-bottom: 1px solid var(--line);
      font-weight: 700;
      text-align: left;
      cursor: pointer;
    }

    .drawer-toggle {
      justify-content: space-between;
    }

    .drawer-toggle::after {
      width: 8px;
      height: 8px;
      margin-right: 5px;
      border-right: 2px solid currentColor;
      border-bottom: 2px solid currentColor;
      content: "";
      transform: rotate(45deg);
      transition: transform 0.2s ease;
    }

    .drawer-toggle.active::after {
      transform: rotate(225deg);
    }

    .drawer-submenu {
      max-height: 0;
      overflow: hidden;
      background: #f7f9fc;
      transition: max-height 0.28s ease;
    }

    .drawer-submenu.open {
      max-height: 720px;
    }

    .drawer-submenu a {
      display: block;
      padding: 10px 14px;
      border-bottom: 1px solid #e9edf3;
      color: #56637a;
      font-size: 13px;
    }

    .drawer-submenu a:hover {
      color: var(--primary);
      background: var(--primary-soft);
    }

    .article-page {
      min-width: 0;
      padding-bottom: 72px;
    }

    .article-page .article-masthead {
      padding: 42px 0 36px;
      color: #ffffff;
      background:
        linear-gradient(90deg, rgba(255, 255, 255, 0.08) 1px, transparent 1px) 0 0 / 38px 38px,
        var(--primary);
      border-bottom: 5px solid #2c9c77;
    }

    .article-page .breadcrumb {
      display: flex;
      flex-wrap: wrap;
      align-items: center;
      gap: 8px;
      margin-bottom: 19px;
      color: #dbe7fa;
      font-size: 13px;
    }

    .article-page .breadcrumb a:hover {
      color: #ffffff;
      text-decoration: underline;
    }

    .article-page .article-category {
      display: inline-flex;
      align-items: center;
      min-height: 28px;
      margin-bottom: 13px;
      padding: 2px 11px;
      color: var(--primary-dark);
      background: #ffffff;
      border-radius: 3px;
      font-size: 12px;
      font-weight: 800;
    }

    .article-page .article-title {
      max-width: 920px;
      margin: 0;
      font-size: clamp(30px, 4vw, 48px);
      line-height: 1.25;
      overflow-wrap: anywhere;
    }

    .article-page .article-meta {
      display: flex;
      flex-wrap: wrap;
      gap: 9px 24px;
      margin-top: 20px;
      color: #dce8fb;
      font-size: 13px;
    }

    .article-page .article-meta span {
      display: inline-flex;
      align-items: center;
      gap: 7px;
    }

    .article-page .article-meta span::before {
      width: 6px;
      height: 6px;
      border-radius: 50%;
      background: #77d1b3;
      content: "";
    }

    .article-page .article-shell {
      min-width: 0;
      display: grid;
      grid-template-columns: minmax(0, 1fr) 300px;
      gap: 30px;
      padding-top: 34px;
    }

    .article-page .article-main,
    .article-page .article-sidebar {
      min-width: 0;
    }

    .article-page .article-paper {
      min-width: 0;
      padding: clamp(24px, 4vw, 48px);
      background: #ffffff;
      border: 1px solid var(--line);
      border-radius: var(--radius);
      box-shadow: 0 8px 26px rgba(16, 34, 64, 0.05);
    }

    .article-page .article-summary {
      margin: 0 0 30px;
      padding: 18px 20px;
      color: #394861;
      background: var(--primary-soft);
      border-left: 4px solid var(--primary);
      font-size: 16px;
      font-weight: 600;
    }

    .article-page .article-content {
      min-width: 0;
      max-width: 100%;
      overflow-x: auto;
      color: #29364b;
      font-size: 16px;
      line-height: 1.9;
      overflow-wrap: anywhere;
    }

    .article-page .article-content h1,
    .article-page .article-content h2,
    .article-page .article-content h3,
    .article-page .article-content h4 {
      margin: 1.8em 0 0.7em;
      color: #14213a;
      line-height: 1.4;
    }

    .article-page .article-content h2 {
      padding-bottom: 10px;
      border-bottom: 1px solid var(--line);
      font-size: 25px;
    }

    .article-page .article-content h3 {
      font-size: 20px;
    }

    .article-page .article-content p,
    .article-page .article-content ul,
    .article-page .article-content ol {
      margin: 0 0 1.25em;
    }

    .article-page .article-content a {
      color: var(--primary);
      text-decoration: underline;
      text-underline-offset: 3px;
    }

    .article-page .article-content img,
    .article-page .article-content video,
    .article-page .article-content iframe {
      max-width: 100%;
      height: auto;
    }

    .article-page .article-content table {
      width: 100%;
      max-width: 100%;
      border-collapse: collapse;
    }

    .article-page .article-content th,
    .article-page .article-content td {
      padding: 10px;
      border: 1px solid var(--line);
      text-align: left;
    }

    .article-page .article-content blockquote {
      margin: 24px 0;
      padding: 15px 20px;
      color: #425069;
      background: #f7f9fc;
      border-left: 4px solid #2c9c77;
    }

    .article-page .article-tags {
      display: flex;
      flex-wrap: wrap;
      align-items: center;
      gap: 8px;
      margin-top: 34px;
      padding-top: 22px;
      border-top: 1px solid var(--line);
    }

    .article-page .article-tags strong {
      margin-right: 4px;
      font-size: 13px;
    }

    .article-page .article-tags a {
      display: inline-flex;
      align-items: center;
      min-height: 30px;
      padding: 3px 10px;
      color: var(--primary);
      background: var(--primary-soft);
      border: 1px solid #ccdaf0;
      border-radius: 3px;
      font-size: 12px;
      font-weight: 700;
    }

    .article-page .article-tags a:hover {
      color: #ffffff;
      background: var(--primary);
    }

    .article-page .article-navigation {
      display: grid;
      grid-template-columns: repeat(2, minmax(0, 1fr));
      gap: 14px;
      margin-top: 22px;
    }

    .article-page .article-navigation a {
      min-width: 0;
      display: block;
      padding: 17px 18px;
      background: #ffffff;
      border: 1px solid var(--line);
      border-radius: var(--radius);
    }

    .article-page .article-navigation a:hover {
      border-color: #adc2e1;
      box-shadow: 0 7px 20px rgba(16, 34, 64, 0.06);
    }

    .article-page .article-navigation small {
      display: block;
      margin-bottom: 5px;
      color: var(--muted);
    }

    .article-page .article-navigation strong {
      display: block;
      color: #21304a;
      font-size: 14px;
      line-height: 1.55;
      overflow-wrap: anywhere;
    }

    .article-page .next-article {
      text-align: right;
    }

    .article-page .sidebar-panel {
      margin-bottom: 18px;
      padding: 20px;
      background: #ffffff;
      border: 1px solid var(--line);
      border-top: 4px solid var(--primary);
      border-radius: var(--radius);
    }

    .article-page .sidebar-panel h2 {
      margin: 0 0 13px;
      font-size: 17px;
    }

    .article-page .sidebar-panel p {
      margin: 0 0 15px;
      color: var(--muted);
      font-size: 13px;
    }

    .article-page .sidebar-links {
      display: grid;
    }

    .article-page .sidebar-links a {
      padding: 10px 0;
      border-bottom: 1px solid var(--line);
      color: #36445d;
      font-size: 13px;
      font-weight: 700;
    }

    .article-page .sidebar-links a:last-child {
      border-bottom: 0;
    }

    .article-page .sidebar-links a:hover {
      color: var(--primary);
    }

    .article-page .sidebar-action {
      display: flex;
      align-items: center;
      justify-content: center;
      min-height: 42px;
      color: #ffffff;
      background: var(--primary);
      border-radius: 4px;
      font-size: 13px;
      font-weight: 800;
    }

    .article-page .sidebar-action:hover {
      background: var(--primary-dark);
    }

    .article-page .related-section {
      margin-top: 44px;
    }

    .article-page .section-heading {
      display: flex;
      align-items: end;
      justify-content: space-between;
      gap: 20px;
      margin-bottom: 18px;
      padding-bottom: 12px;
      border-bottom: 2px solid var(--line);
    }

    .article-page .section-heading h2 {
      margin: 0;
      font-size: 24px;
    }

    .article-page .section-heading a {
      color: var(--primary);
      font-size: 13px;
      font-weight: 800;
    }

    .article-page .related-grid {
      display: grid;
      grid-template-columns: repeat(3, minmax(0, 1fr));
      gap: 18px;
    }

    .article-page .related-card {
      min-width: 0;
      overflow: hidden;
      background: #ffffff;
      border: 1px solid var(--line);
      border-radius: var(--radius);
      transition: border-color 0.18s ease, transform 0.18s ease, box-shadow 0.18s ease;
    }

    .article-page .related-card:hover {
      border-color: #b5c7e2;
      box-shadow: var(--shadow);
      transform: translateY(-3px);
    }

    .article-page .related-image {
      aspect-ratio: 16 / 9;
      overflow: hidden;
      background: #e8edf5;
    }

    .article-page .related-image img {
      width: 100%;
      height: 100%;
      object-fit: cover;
      transition: transform 0.25s ease;
    }

    .article-page .related-card:hover .related-image img {
      transform: scale(1.035);
    }

    .article-page .related-body {
      min-width: 0;
      padding: 16px;
    }

    .article-page .related-body h3 {
      min-height: 48px;
      margin: 0 0 9px;
      color: #1c2a42;
      font-size: 16px;
      line-height: 1.5;
      overflow-wrap: anywhere;
    }

    .article-page .related-summary {
      min-height: 63px;
      margin: 0 0 13px;
      color: var(--muted);
      font-size: 13px;
      line-height: 1.65;
      display: -webkit-box;
      overflow: hidden;
      -webkit-box-orient: vertical;
      -webkit-line-clamp: 3;
    }

    .article-page .related-meta {
      display: flex;
      flex-wrap: wrap;
      justify-content: space-between;
      gap: 6px 12px;
      padding-top: 11px;
      border-top: 1px solid var(--line);
      color: #7a8598;
      font-size: 11px;
    }

    .footer {
      color: #cbd5e5;
      background: #111b2d;
      border-top: 5px solid var(--primary);
    }

    .footer-grid {
      display: grid;
      grid-template-columns: 1.5fr repeat(3, 1fr);
      gap: 46px;
      padding: 52px 0 38px;
    }

    .footer-brand strong {
      display: block;
      margin-bottom: 12px;
      color: #ffffff;
      font-size: 20px;
    }

    .footer h3 {
      margin: 0 0 15px;
      color: #ffffff;
      font-size: 15px;
    }

    .footer p {
      margin: 0 0 12px;
      color: #9eabc0;
      font-size: 13px;
    }

    .footer-grid > div > a {
      display: block;
      width: fit-content;
      margin: 0 0 9px;
      color: #b8c4d6;
      font-size: 13px;
    }

    .footer-grid > div > a:hover {
      color: #ffffff;
    }

    .footer-bottom {
      min-height: 68px;
      display: flex;
      align-items: center;
      justify-content: space-between;
      gap: 24px;
      padding: 16px 0;
      border-top: 1px solid #2a3548;
      color: #8996aa;
      font-size: 12px;
    }

    @media (max-width: 1120px) {
      .header-inner {
        gap: 16px;
      }

      .logo {
        min-width: auto;
      }

      .nav-link {
        padding: 0 9px;
      }

      .member-btn {
        display: none;
      }
    }

    @media (max-width: 960px) {
      .main-nav {
        display: none;
      }

      .header-inner {
        min-height: 68px;
      }

      .header-btns {
        margin-left: auto;
      }

      .hamburger {
        display: inline-block;
      }

      .article-page .article-shell {
        grid-template-columns: minmax(0, 1fr);
      }

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

      .article-page .sidebar-panel {
        margin-bottom: 0;
      }

      .footer-grid {
        grid-template-columns: repeat(2, minmax(0, 1fr));
      }
    }

    @media (max-width: 720px) {
      .container {
        width: min(100% - 28px, 1180px);
      }

      .topbar {
        display: none;
      }

      .logo {
        min-width: 0;
      }

      .logo span {
        max-width: 150px;
        overflow: hidden;
        text-overflow: ellipsis;
      }

      .open-btn {
        display: none;
      }

      .article-page .article-masthead {
        padding: 30px 0;
      }

      .article-page .article-title {
        font-size: 30px;
      }

      .article-page .article-shell {
        padding-top: 22px;
      }

      .article-page .article-paper {
        padding: 22px 18px;
      }

      .article-page .article-navigation {
        grid-template-columns: 1fr;
      }

      .article-page .next-article {
        text-align: left;
      }

      .article-page .article-sidebar {
        grid-template-columns: 1fr;
      }

      .article-page .related-grid {
        grid-template-columns: 1fr;
      }

      .article-page .related-card {
        display: grid;
        grid-template-columns: 128px minmax(0, 1fr);
      }

      .article-page .related-image {
        height: 100%;
        min-height: 150px;
        aspect-ratio: auto;
      }

      .article-page .related-body h3,
      .article-page .related-summary {
        min-height: 0;
      }

      .footer-grid {
        grid-template-columns: 1fr;
        gap: 28px;
        padding: 38px 0 28px;
      }

      .footer-bottom {
        align-items: flex-start;
        flex-direction: column;
        gap: 8px;
      }
    }

    @media (max-width: 460px) {
      .logo img {
        width: 36px;
        height: 36px;
      }

      .logo span {
        max-width: 120px;
        font-size: 16px;
      }

      .article-page .article-title {
        font-size: 27px;
      }

      .article-page .article-meta {
        display: grid;
        gap: 6px;
      }

      .article-page .article-summary,
      .article-page .article-content {
        font-size: 15px;
      }

      .article-page .section-heading {
        align-items: flex-start;
        flex-direction: column;
        gap: 6px;
      }

      .article-page .related-card {
        display: block;
      }

      .article-page .related-image {
        min-height: 0;
        aspect-ratio: 16 / 9;
      }
    }