/* roulang page: index */
:root{
      --bg: #f4f8fd;
      --bg-2: #eef4fb;
      --surface: rgba(255,255,255,.86);
      --surface-strong: #ffffff;
      --surface-soft: #f8fbff;
      --primary: #1d67d8;
      --primary-strong: #1550b4;
      --accent: #56bbff;
      --accent-2: #8ce0ff;
      --text: #12263a;
      --muted: #62778f;
      --soft: #8a9ab0;
      --border: rgba(20, 44, 74, .10);
      --border-strong: rgba(29,103,216,.20);
      --shadow: 0 18px 48px rgba(18, 38, 58, .08);
      --shadow-strong: 0 22px 60px rgba(18, 38, 58, .14);
      --radius-xl: 30px;
      --radius-lg: 24px;
      --radius-md: 18px;
      --radius-sm: 14px;
      --container: 1180px;
      --gap: 18px;
    }

    * { box-sizing: border-box; }
    html {
      scroll-behavior: smooth;
      -webkit-text-size-adjust: 100%;
    }
    body {
      margin: 0;
      color: var(--text);
      font-family: -apple-system, BlinkMacSystemFont, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Noto Sans CJK SC", sans-serif;
      line-height: 1.75;
      background:
        radial-gradient(circle at 0% 0%, rgba(29, 103, 216, .12) 0%, rgba(29, 103, 216, 0) 36%),
        radial-gradient(circle at 100% 0%, rgba(86, 187, 255, .10) 0%, rgba(86, 187, 255, 0) 32%),
        linear-gradient(180deg, #f8fbff 0%, #f4f8fd 34%, #edf4fb 100%);
      text-rendering: optimizeLegibility;
    }
    ::selection {
      background: rgba(29,103,216,.18);
      color: var(--text);
    }
    a {
      color: inherit;
      text-decoration: none;
    }
    img {
      display: block;
      max-width: 100%;
    }
    button,
    input,
    select,
    textarea {
      font: inherit;
    }
    button {
      cursor: pointer;
    }
    :focus-visible {
      outline: 3px solid rgba(29,103,216,.28);
      outline-offset: 3px;
    }
    .container {
      width: min(var(--container), calc(100% - 32px));
      margin: 0 auto;
    }
    .sr-only {
      position: absolute;
      width: 1px;
      height: 1px;
      margin: -1px;
      padding: 0;
      border: 0;
      clip: rect(0, 0, 0, 0);
      overflow: hidden;
      white-space: nowrap;
    }

    .site-header {
      position: sticky;
      top: 0;
      z-index: 50;
      backdrop-filter: blur(16px);
      -webkit-backdrop-filter: blur(16px);
      background: rgba(247, 251, 255, .78);
      border-bottom: 1px solid rgba(216, 228, 240, .72);
    }
    .site-header .inner {
      display: flex;
      align-items: center;
      gap: 14px;
      padding: 14px 0;
      flex-wrap: wrap;
    }
    .brand {
      display: inline-flex;
      align-items: center;
      gap: 12px;
      font-weight: 800;
      color: var(--text);
      letter-spacing: .2px;
      flex: 0 0 auto;
      white-space: nowrap;
    }
    .brand-mark {
      width: 40px;
      height: 40px;
      border-radius: 14px;
      display: grid;
      place-items: center;
      color: #fff;
      background: linear-gradient(135deg, var(--primary), var(--accent));
      box-shadow: 0 14px 28px rgba(29, 103, 216, .26);
      font-size: .84rem;
      letter-spacing: .08em;
    }
    .brand-text {
      font-size: 1.04rem;
    }
    .site-nav {
      display: flex;
      align-items: center;
      justify-content: center;
      gap: 10px;
      flex: 1 1 220px;
      min-width: 0;
    }
    .site-nav a {
      padding: 10px 16px;
      border-radius: 999px;
      color: var(--muted);
      border: 1px solid transparent;
      transition: .22s ease;
      white-space: nowrap;
      font-weight: 600;
    }
    .site-nav a:hover,
    .site-nav a:focus-visible,
    .site-nav a.active {
      background: rgba(29,103,216,.08);
      color: var(--primary-strong);
      border-color: rgba(29,103,216,.15);
    }
    .header-tools {
      display: flex;
      align-items: center;
      gap: 10px;
      margin-left: auto;
      flex: 0 0 auto;
    }
    .site-search {
      display: flex;
      align-items: center;
      gap: 8px;
      padding: 7px 8px 7px 14px;
      border-radius: 999px;
      background: var(--surface-strong);
      border: 1px solid var(--border);
      box-shadow: var(--shadow);
      transition: .22s ease;
    }
    .site-search:focus-within {
      border-color: rgba(29,103,216,.24);
      box-shadow: 0 16px 40px rgba(18, 38, 58, .10);
      transform: translateY(-1px);
    }
    .site-search .icon {
      color: var(--soft);
      font-size: .95rem;
      line-height: 1;
    }
    .site-search input {
      border: 0;
      outline: 0;
      background: transparent;
      min-width: 230px;
      color: var(--text);
    }
    .site-search input::placeholder {
      color: #93a3b7;
    }
    .site-search button {
      border: 0;
      background: linear-gradient(135deg, var(--primary), #4aa4ff);
      color: #fff;
      font-weight: 700;
      border-radius: 999px;
      padding: 11px 16px;
      transition: .22s ease;
      box-shadow: 0 12px 24px rgba(29, 103, 216, .20);
    }
    .site-search button:hover {
      transform: translateY(-1px);
      box-shadow: 0 16px 28px rgba(29, 103, 216, .28);
    }
    .site-search button:active {
      transform: translateY(0);
    }
    .locale-switch {
      display: inline-flex;
      gap: 8px;
      padding: 4px;
      border-radius: 999px;
      background: rgba(255,255,255,.72);
      border: 1px solid var(--border);
      box-shadow: var(--shadow);
    }
    .locale-switch .pill {
      border: 0;
      background: transparent;
      color: var(--muted);
      border-radius: 999px;
      padding: 9px 14px;
      transition: .22s ease;
      font-weight: 700;
      min-width: 68px;
    }
    .locale-switch .pill.active {
      color: var(--primary-strong);
      background: rgba(29,103,216,.10);
      box-shadow: inset 0 0 0 1px rgba(29,103,216,.12);
    }

    main {
      display: block;
    }
    section {
      padding: 74px 0;
      scroll-margin-top: 88px;
    }

    .hero {
      position: relative;
      overflow: hidden;
      padding-top: 40px;
      padding-bottom: 34px;
    }
    .hero::before,
    .hero::after {
      content: "";
      position: absolute;
      border-radius: 999px;
      pointer-events: none;
      filter: blur(5px);
    }
    .hero::before {
      width: 300px;
      height: 300px;
      left: -100px;
      top: 50px;
      background: radial-gradient(circle, rgba(86,187,255,.20) 0%, rgba(86,187,255,0) 72%);
    }
    .hero::after {
      width: 360px;
      height: 360px;
      right: -130px;
      top: 90px;
      background: radial-gradient(circle, rgba(29,103,216,.14) 0%, rgba(29,103,216,0) 72%);
    }
    .hero-grid {
      position: relative;
      display: grid;
      grid-template-columns: 1.05fr .95fr;
      gap: 28px;
      align-items: center;
    }
    .eyebrow {
      display: inline-flex;
      align-items: center;
      gap: 8px;
      border-radius: 999px;
      padding: 8px 14px;
      color: var(--primary-strong);
      background: rgba(29,103,216,.10);
      border: 1px solid rgba(29,103,216,.12);
      font-size: .92rem;
      font-weight: 700;
      letter-spacing: .02em;
    }
    .hero h1 {
      margin: 18px 0 16px;
      font-size: clamp(2.2rem, 5vw, 4.5rem);
      line-height: 1.08;
      letter-spacing: -.04em;
      color: var(--text);
    }
    .hero .lead {
      max-width: 58ch;
      margin: 0;
      font-size: 1.06rem;
      color: var(--muted);
    }
    .hero-actions {
      display: flex;
      flex-wrap: wrap;
      gap: 14px;
      margin-top: 28px;
    }
    .btn {
      display: inline-flex;
      align-items: center;
      justify-content: center;
      gap: 8px;
      border: 1px solid transparent;
      border-radius: 999px;
      padding: 13px 20px;
      min-height: 48px;
      font-weight: 800;
      transition: .22s ease;
      box-shadow: 0 0 0 rgba(0,0,0,0);
      will-change: transform;
    }
    .btn:hover {
      transform: translateY(-2px);
    }
    .btn:active {
      transform: translateY(0);
    }
    .btn.primary {
      color: #fff;
      background: linear-gradient(135deg, var(--primary), #4aa4ff);
      box-shadow: 0 16px 34px rgba(29, 103, 216, .24);
    }
    .btn.primary:hover {
      box-shadow: 0 20px 38px rgba(29, 103, 216, .32);
    }
    .btn.secondary {
      color: var(--text);
      background: rgba(255,255,255,.88);
      border-color: var(--border);
      box-shadow: var(--shadow);
    }
    .btn.secondary:hover {
      border-color: rgba(29,103,216,.20);
      color: var(--primary-strong);
    }

    .hero-stats {
      display: grid;
      grid-template-columns: repeat(4, minmax(0, 1fr));
      gap: 12px;
      margin-top: 30px;
    }
    .hero-stat {
      padding: 14px 16px;
      border-radius: 18px;
      border: 1px solid var(--border);
      background: rgba(255,255,255,.76);
      box-shadow: var(--shadow);
    }
    .hero-stat strong {
      display: block;
      font-size: 1.28rem;
      line-height: 1.1;
      margin-bottom: 4px;
    }
    .hero-stat span {
      color: var(--muted);
      font-size: .94rem;
    }

    .hero-stage {
      position: relative;
      border-radius: 32px;
      padding: 22px;
      border: 1px solid rgba(29,103,216,.12);
      background:
        linear-gradient(180deg, rgba(255,255,255,.92), rgba(240,246,253,.96)),
        linear-gradient(135deg, rgba(29,103,216,.06), rgba(86,187,255,.04));
      box-shadow: var(--shadow-strong);
      overflow: hidden;
    }
    .hero-stage::before,
    .hero-stage::after {
      content: "";
      position: absolute;
      border-radius: 999px;
      pointer-events: none;
    }
    .hero-stage::before {
      width: 220px;
      height: 220px;
      left: -80px;
      top: -70px;
      background: radial-gradient(circle, rgba(86,187,255,.24) 0%, rgba(86,187,255,0) 70%);
    }
    .hero-stage::after {
      width: 260px;
      height: 260px;
      right: -90px;
      bottom: -100px;
      background: radial-gradient(circle, rgba(29,103,216,.16) 0%, rgba(29,103,216,0) 70%);
    }
    .stage-toolbar {
      position: relative;
      z-index: 1;
      display: flex;
      flex-wrap: wrap;
      gap: 10px;
      margin-bottom: 14px;
    }
    .badge {
      display: inline-flex;
      align-items: center;
      gap: 6px;
      border-radius: 999px;
      padding: 7px 12px;
      font-size: .86rem;
      font-weight: 700;
      white-space: nowrap;
    }
    .badge.soft {
      background: rgba(29,103,216,.10);
      color: var(--primary-strong);
      border: 1px solid rgba(29,103,216,.12);
    }
    .badge.alt {
      background: rgba(86,187,255,.14);
      color: #0e5e8f;
      border: 1px solid rgba(86,187,255,.16);
    }
    .badge.gray {
      background: rgba(98,119,143,.10);
      color: var(--muted);
      border: 1px solid rgba(98,119,143,.10);
    }

    .stage-grid {
      position: relative;
      z-index: 1;
      display: grid;
      grid-template-columns: 1.2fr .8fr;
      gap: 14px;
    }
    .stage-card,
    .panel,
    .feature-spot,
    .feature-card,
    .step-card,
    .metric-card,
    .device-card,
    .post-card,
    .plan-card,
    .faq-details,
    .cta-panel,
    .update-panel,
    .side-panel,
    .footer-card {
      background: var(--surface);
      border: 1px solid var(--border);
      border-radius: var(--radius-lg);
      box-shadow: var(--shadow);
    }
    .stage-card {
      padding: 20px;
    }
    .stage-main {
      min-height: 290px;
      background:
        linear-gradient(135deg, rgba(29,103,216,.98), rgba(77,175,255,.84)),
        linear-gradient(180deg, rgba(255,255,255,.10), rgba(255,255,255,0));
      color: #fff;
      border-color: rgba(255,255,255,.16);
      position: relative;
      overflow: hidden;
    }
    .stage-main::before {
      content: "";
      position: absolute;
      inset: auto -30px -60px auto;
      width: 180px;
      height: 180px;
      border-radius: 50%;
      background: radial-gradient(circle, rgba(255,255,255,.20) 0%, rgba(255,255,255,0) 68%);
    }
    .stage-main .stage-top {
      display: flex;
      align-items: center;
      justify-content: space-between;
      gap: 12px;
      margin-bottom: 18px;
      position: relative;
      z-index: 1;
    }
    .stage-main .stage-title {
      margin: 0 0 10px;
      font-size: 1.5rem;
      line-height: 1.2;
      letter-spacing: -.02em;
      position: relative;
      z-index: 1;
    }
    .stage-main .stage-desc {
      margin: 0;
      color: rgba(255,255,255,.88);
      position: relative;
      z-index: 1;
    }
    .progress {
      margin-top: 22px;
      height: 10px;
      border-radius: 999px;
      background: rgba(255,255,255,.18);
      overflow: hidden;
      position: relative;
      z-index: 1;
    }
    .progress span {
      display: block;
      height: 100%;
      width: 72%;
      border-radius: inherit;
      background: linear-gradient(90deg, rgba(255,255,255,.82), rgba(255,255,255,.98));
    }
    .stage-footer {
      margin-top: 18px;
      display: flex;
      justify-content: space-between;
      gap: 12px;
      align-items: end;
      position: relative;
      z-index: 1;
    }
    .stage-footer strong {
      font-size: 1.3rem;
    }
    .stage-footer span {
      color: rgba(255,255,255,.8);
      font-size: .94rem;
    }
    .stage-aside {
      display: grid;
      gap: 14px;
    }
    .mini-card {
      min-height: 88px;
      padding: 18px;
      border-radius: 22px;
      background: rgba(255,255,255,.86);
      border: 1px solid var(--border);
      box-shadow: var(--shadow);
      display: flex;
      align-items: center;
      justify-content: space-between;
      gap: 14px;
      transition: .22s ease;
    }
    .mini-card:hover {
      transform: translateY(-2px);
      box-shadow: var(--shadow-strong);
    }
    .mini-card .txt {
      min-width: 0;
    }
    .mini-card h3,
    .mini-card p {
      margin: 0;
    }
    .mini-card h3 {
      font-size: 1rem;
      margin-bottom: 4px;
    }
    .mini-card p {
      color: var(--muted);
      font-size: .92rem;
      line-height: 1.55;
    }
    .mini-chart {
      width: 84px;
      height: 44px;
      border-radius: 16px;
      background:
        linear-gradient(180deg, rgba(29,103,216,.14), rgba(29,103,216,.05)),
        linear-gradient(90deg, rgba(29,103,216,.16), rgba(86,187,255,.08));
      border: 1px solid rgba(29,103,216,.10);
      position: relative;
      overflow: hidden;
      flex: 0 0 auto;
    }
    .mini-chart::before,
    .mini-chart::after {
      content: "";
      position: absolute;
      left: 12px;
      right: 12px;
      height: 2px;
      border-radius: 999px;
      background: rgba(29,103,216,.22);
    }
    .mini-chart::before {
      top: 13px;
      box-shadow: 0 10px 0 rgba(29,103,216,.18), 0 20px 0 rgba(29,103,216,.16);
    }
    .mini-chart::after {
      top: 27px;
      background: linear-gradient(90deg, var(--primary), var(--accent));
      height: 4px;
      width: 56%;
      right: auto;
    }

    .section-head {
      display: flex;
      align-items: end;
      justify-content: space-between;
      gap: 20px;
      margin-bottom: 28px;
    }
    .section-head h2 {
      margin: 0;
      font-size: clamp(1.6rem, 3vw, 2.4rem);
      line-height: 1.18;
      letter-spacing: -.03em;
    }
    .section-head p {
      margin: 0;
      color: var(--muted);
      max-width: 60ch;
    }

    .feature-layout {
      display: grid;
      grid-template-columns: 1.08fr .92fr;
      gap: 18px;
      align-items: stretch;
    }
    .feature-spot {
      position: relative;
      overflow: hidden;
      padding: 28px;
      color: #fff;
      min-height: 360px;
      background:
        linear-gradient(135deg, rgba(17, 77, 180, .98), rgba(50, 137, 238, .92)),
        radial-gradient(circle at top right, rgba(255,255,255,.15) 0%, rgba(255,255,255,0) 52%);
    }
    .feature-spot::before,
    .feature-spot::after {
      content: "";
      position: absolute;
      border-radius: 999px;
      pointer-events: none;
    }
    .feature-spot::before {
      width: 260px;
      height: 260px;
      right: -120px;
      top: -90px;
      background: radial-gradient(circle, rgba(255,255,255,.14) 0%, rgba(255,255,255,0) 70%);
    }
    .feature-spot::after {
      width: 220px;
      height: 220px;
      left: -110px;
      bottom: -110px;
      background: radial-gradient(circle, rgba(255,255,255,.08) 0%, rgba(255,255,255,0) 68%);
    }
    .feature-spot .eyebrow {
      background: rgba(255,255,255,.14);
      color: #fff;
      border-color: rgba(255,255,255,.18);
      position: relative;
      z-index: 1;
    }
    .feature-spot h3 {
      margin: 18px 0 12px;
      font-size: 1.7rem;
      line-height: 1.18;
      position: relative;
      z-index: 1;
    }
    .feature-spot p {
      margin: 0;
      color: rgba(255,255,255,.90);
      max-width: 36ch;
      position: relative;
      z-index: 1;
    }
    .feature-tags {
      display: flex;
      flex-wrap: wrap;
      gap: 10px;
      margin-top: 22px;
      position: relative;
      z-index: 1;
    }
    .feature-tags .tag {
      padding: 9px 12px;
      border-radius: 999px;
      background: rgba(255,255,255,.16);
      color: #fff;
      border: 1px solid rgba(255,255,255,.18);
      font-weight: 700;
      font-size: .88rem;
    }
    .feature-stack {
      display: grid;
      gap: 14px;
    }
    .feature-card {
      padding: 20px;
      transition: .22s ease;
      position: relative;
      overflow: hidden;
    }
    .feature-card:hover {
      transform: translateY(-2px);
      box-shadow: var(--shadow-strong);
      border-color: rgba(29,103,216,.18);
    }
    .feature-card .topline {
      display: flex;
      align-items: center;
      justify-content: space-between;
      gap: 12px;
      margin-bottom: 12px;
    }
    .feature-card h3 {
      margin: 0;
      font-size: 1.08rem;
    }
    .feature-card p {
      margin: 0;
      color: var(--muted);
    }
    .feature-card .mini-label {
      display: inline-flex;
      align-items: center;
      gap: 6px;
      border-radius: 999px;
      padding: 6px 10px;
      background: rgba(29,103,216,.10);
      color: var(--primary-strong);
      font-weight: 700;
      font-size: .82rem;
    }
    .feature-card.feature-small {
      display: grid;
      grid-template-columns: auto 1fr;
      gap: 14px;
      align-items: start;
    }
    .feature-icon {
      width: 46px;
      height: 46px;
      border-radius: 16px;
      display: grid;
      place-items: center;
      color: var(--primary-strong);
      background: linear-gradient(180deg, rgba(29,103,216,.10), rgba(86,187,255,.08));
      border: 1px solid rgba(29,103,216,.12);
      font-weight: 800;
      flex: 0 0 auto;
    }

    .step-grid {
      display: grid;
      grid-template-columns: repeat(4, minmax(0, 1fr));
      gap: 16px;
    }
    .step-card {
      padding: 22px;
      transition: .22s ease;
    }
    .step-card:hover {
      transform: translateY(-2px);
      box-shadow: var(--shadow-strong);
      border-color: rgba(29,103,216,.18);
    }
    .step-number {
      width: 42px;
      height: 42px;
      border-radius: 14px;
      display: grid;
      place-items: center;
      color: #fff;
      font-weight: 800;
      background: linear-gradient(135deg, var(--primary), var(--accent));
      box-shadow: 0 14px 26px rgba(29,103,216,.22);
      margin-bottom: 16px;
    }
    .step-card h3 {
      margin: 0 0 8px;
      font-size: 1.08rem;
    }
    .step-card p {
      margin: 0;
      color: var(--muted);
    }

    .stats-shell {
      display: grid;
      grid-template-columns: 1.25fr .75fr;
      gap: 16px;
      align-items: stretch;
    }
    .stats-grid {
      display: grid;
      grid-template-columns: repeat(2, minmax(0, 1fr));
      gap: 16px;
    }
    .metric-card {
      padding: 22px;
      transition: .22s ease;
    }
    .metric-card:hover {
      transform: translateY(-2px);
      border-color: rgba(29,103,216,.16);
      box-shadow: var(--shadow-strong);
    }
    .metric-value {
      font-size: 2.2rem;
      line-height: 1;
      font-weight: 900;
      letter-spacing: -.04em;
      color: var(--primary-strong);
      margin-bottom: 10px;
    }
    .metric-card p {
      margin: 0;
      color: var(--muted);
    }
    .metric-card .mini-note {
      margin-top: 14px;
      display: inline-flex;
      align-items: center;
      padding: 7px 10px;
      border-radius: 999px;
      background: rgba(29,103,216,.08);
      color: var(--primary-strong);
      font-weight: 700;
      font-size: .84rem;
    }
    .device-card {
      padding: 22px;
      display: grid;
      align-content: start;
      gap: 16px;
      background:
        linear-gradient(180deg, rgba(255,255,255,.88), rgba(240,247,254,.96));
      overflow: hidden;
      position: relative;
    }
    .device-card::before {
      content: "";
      position: absolute;
      width: 190px;
      height: 190px;
      border-radius: 50%;
      right: -90px;
      top: -70px;
      background: radial-gradient(circle, rgba(29,103,216,.12) 0%, rgba(29,103,216,0) 70%);
      pointer-events: none;
    }
    .device-card .phone {
      width: min(100%, 250px);
      margin-inline: auto;
      border-radius: 28px;
      padding: 14px;
      background: linear-gradient(180deg, #1b2740, #102038);
      box-shadow: 0 24px 60px rgba(18, 38, 58, .24);
      position: relative;
      overflow: hidden;
    }
    .phone-screen {
      background: linear-gradient(180deg, rgba(245,250,255,.95), rgba(228,238,248,.92));
      border-radius: 22px;
      padding: 14px;
      min-height: 270px;
      display: grid;
      gap: 10px;
    }
    .phone-top {
      display: flex;
      align-items: center;
      justify-content: space-between;
      gap: 8px;
    }
    .phone-dot {
      width: 11px;
      height: 11px;
      border-radius: 50%;
      background: linear-gradient(135deg, var(--primary), var(--accent));
      box-shadow: 0 0 0 4px rgba(29,103,216,.10);
    }
    .phone-card {
      border-radius: 18px;
      background: rgba(255,255,255,.92);
      border: 1px solid rgba(20,44,74,.08);
      padding: 12px;
      display: grid;
      gap: 8px;
    }
    .phone-card .line {
      height: 10px;
      border-radius: 999px;
      background: linear-gradient(90deg, rgba(29,103,216,.22), rgba(86,187,255,.12));
    }
    .phone-card .line.short {
      width: 66%;
    }
    .device-card h3 {
      margin: 0;
      font-size: 1.1rem;
    }
    .device-card p {
      margin: 0;
      color: var(--muted);
    }
    .device-points {
      display: grid;
      gap: 10px;
      margin: 0;
      padding: 0;
      list-style: none;
    }
    .device-points li {
      display: flex;
      gap: 10px;
      align-items: start;
      color: var(--muted);
    }
    .device-points li::before {
      content: "•";
      color: var(--primary);
      font-weight: 900;
      line-height: 1.5;
      margin-top: .05em;
    }

    .panel-block {
      background: rgba(255,255,255,.70);
      border: 1px solid var(--border);
      border-radius: var(--radius-lg);
      box-shadow: var(--shadow);
      padding: 22px;
    }

    .latest-grid {
      display: grid;
      grid-template-columns: 1.35fr .65fr;
      gap: 16px;
      align-items: start;
    }
    .post-list {
      display: grid;
      gap: 14px;
    }
    .post-card {
      display: block;
      padding: 20px 20px 18px;
      transition: .22s ease;
      overflow: hidden;
    }
    .post-card:hover {
      transform: translateY(-2px);
      box-shadow: var(--shadow-strong);
      border-color: rgba(29,103,216,.18);
    }
    .post-top {
      display: flex;
      justify-content: space-between;
      align-items: center;
      gap: 12px;
      margin-bottom: 10px;
      flex-wrap: wrap;
    }
    .post-top time {
      color: var(--soft);
      font-size: .92rem;
      white-space: nowrap;
    }
    .post-card h3 {
      margin: 0 0 10px;
      font-size: 1.14rem;
      line-height: 1.35;
      letter-spacing: -.02em;
    }
    .post-card p {
      margin: 0;
      color: var(--muted);
      line-height: 1.68;
    }
    .post-bottom {
      display: flex;
      align-items: center;
      justify-content: space-between;
      gap: 12px;
      margin-top: 16px;
      color: var(--primary-strong);
      font-weight: 700;
    }
    .post-bottom .arrow {
      transition: .22s ease;
    }
    .post-card:hover .arrow {
      transform: translateX(4px);
    }
    .empty-state {
      padding: 28px 20px;
      text-align: center;
      color: var(--muted);
      border-radius: 22px;
      border: 1px dashed rgba(29,103,216,.22);
      background: rgba(255,255,255,.66);
    }
    .side-panel {
      padding: 20px;
      position: sticky;
      top: 92px;
    }
    .side-panel h3 {
      margin: 0 0 8px;
      font-size: 1.08rem;
    }
    .side-panel p {
      margin: 0;
      color: var(--muted);
    }
    .quick-links {
      display: grid;
      gap: 10px;
      margin-top: 16px;
    }
    .quick-link {
      display: flex;
      align-items: center;
      justify-content: space-between;
      gap: 12px;
      border-radius: 16px;
      padding: 13px 14px;
      background: rgba(248,251,255,.96);
      border: 1px solid rgba(20,44,74,.08);
      transition: .22s ease;
      color: var(--text);
      font-weight: 600;
    }
    .quick-link:hover {
      transform: translateY(-1px);
      border-color: rgba(29,103,216,.18);
      color: var(--primary-strong);
      box-shadow: 0 12px 22px rgba(18, 38, 58, .06);
    }
    .quick-link span:last-child {
      color: var(--soft);
    }

    .plan-grid {
      display: grid;
      grid-template-columns: repeat(3, minmax(0, 1fr));
      gap: 16px;
    }
    .plan-card {
      position: relative;
      padding: 24px;
      overflow: hidden;
      transition: .22s ease;
    }
    .plan-card::before {
      content: "";
      position: absolute;
      right: -46px;
      top: -52px;
      width: 140px;
      height: 140px;
      border-radius: 50%;
      background: radial-gradient(circle, rgba(29,103,216,.10) 0%, rgba(29,103,216,0) 70%);
      pointer-events: none;
    }
    .plan-card:hover {
      transform: translateY(-3px);
      box-shadow: var(--shadow-strong);
      border-color: rgba(29,103,216,.18);
    }
    .plan-card.featured {
      background: linear-gradient(180deg, rgba(255,255,255,.98), rgba(240,247,255,.94));
      border-color: rgba(29,103,216,.18);
      transform: translateY(-4px);
    }
    .plan-card.featured:hover {
      transform: translateY(-6px);
    }
    .plan-card h3 {
      margin: 0;
      font-size: 1.18rem;
    }
    .plan-price {
      margin: 14px 0 6px;
      font-size: 2.2rem;
      font-weight: 900;
      letter-spacing: -.04em;
      color: var(--primary-strong);
    }
    .plan-sub {
      margin: 0;
      color: var(--muted);
    }
    .plan-list {
      list-style: none;
      padding: 0;
      margin: 18px 0 22px;
      display: grid;
      gap: 10px;
    }
    .plan-list li {
      display: flex;
      gap: 10px;
      align-items: start;
      color: var(--muted);
    }
    .plan-list li::before {
      content: "";
      width: 10px;
      height: 10px;
      margin-top: .5em;
      border-radius: 999px;
      background: linear-gradient(135deg, var(--primary), var(--accent));
      box-shadow: 0 0 0 4px rgba(29,103,216,.08);
      flex: 0 0 auto;
    }
    .plan-card .btn {
      width: 100%;
    }

    .faq-list {
      display: grid;
      gap: 14px;
    }
    .faq-details {
      padding: 0 18px;
      overflow: hidden;
      transition: .22s ease;
    }
    .faq-details[open] {
      border-color: rgba(29,103,216,.18);
      box-shadow: var(--shadow-strong);
    }
    .faq-details summary {
      list-style: none;
      cursor: pointer;
      display: flex;
      align-items: center;
      justify-content: space-between;
      gap: 14px;
      font-weight: 800;
      padding: 18px 0;
      color: var(--text);
      transition: .22s ease;
    }
    .faq-details summary::-webkit-details-marker {
      display: none;
    }
    .faq-details summary .sign {
      width: 30px;
      height: 30px;
      border-radius: 999px;
      display: grid;
      place-items: center;
      color: var(--primary-strong);
      background: rgba(29,103,216,.10);
      border: 1px solid rgba(29,103,216,.10);
      flex: 0 0 auto;
      transition: .22s ease;
    }
    .faq-details[open] summary .sign {
      transform: rotate(45deg);
      background: rgba(29,103,216,.12);
    }
    .faq-details p {
      margin: 0 0 18px;
      color: var(--muted);
      padding-right: 8px;
    }

    .cta-wrap {
      display: grid;
      grid-template-columns: 1.05fr .95fr;
      gap: 16px;
      align-items: stretch;
    }
    .cta-panel {
      padding: 28px;
      position: relative;
      overflow: hidden;
    }
    .cta-panel::before {
      content: "";
      position: absolute;
      width: 240px;
      height: 240px;
      right: -80px;
      top: -80px;
      border-radius: 50%;
      background: radial-gradient(circle, rgba(86,187,255,.14) 0%, rgba(86,187,255,0) 68%);
      pointer-events: none;
    }
    .cta-panel h2 {
      margin: 0 0 14px;
      font-size: clamp(1.8rem, 3vw, 2.4rem);
      line-height: 1.18;
      letter-spacing: -.03em;
    }
    .cta-panel p {
      margin: 0;
      color: var(--muted);
      max-width: 58ch;
    }
    .cta-points {
      display: flex;
      flex-wrap: wrap;
      gap: 10px;
      margin-top: 18px;
    }
    .cta-points .badge {
      background: rgba(29,103,216,.08);
      color: var(--primary-strong);
      border: 1px solid rgba(29,103,216,.10);
    }
    .cta-actions {
      display: flex;
      flex-wrap: wrap;
      gap: 12px;
      margin-top: 24px;
    }
    .update-panel {
      padding: 24px;
      background: linear-gradient(180deg, rgba(255,255,255,.94), rgba(240,246,253,.96));
    }
    .update-panel h3 {
      margin: 0 0 10px;
      font-size: 1.14rem;
    }
    .update-panel p {
      margin: 0;
      color: var(--muted);
    }
    .timeline {
      margin-top: 16px;
      display: grid;
      gap: 12px;
    }
    .timeline-item {
      display: grid;
      grid-template-columns: auto 1fr;
      gap: 12px;
      align-items: start;
      padding-top: 12px;
      border-top: 1px solid rgba(20,44,74,.08);
    }
    .timeline-item:first-child {
      border-top: 0;
      padding-top: 0;
    }
    .timeline-dot {
      width: 12px;
      height: 12px;
      border-radius: 50%;
      margin-top: .5em;
      background: linear-gradient(135deg, var(--primary), var(--accent));
      box-shadow: 0 0 0 4px rgba(29,103,216,.08);
    }
    .timeline-item strong {
      display: block;
      margin-bottom: 4px;
      color: var(--text);
    }
    .timeline-item span {
      color: var(--muted);
    }

    .site-footer {
      padding: 34px 0 42px;
      border-top: 1px solid rgba(216, 228, 240, .86);
      background: rgba(255,255,255,.48);
    }
    .footer-grid {
      display: grid;
      grid-template-columns: 1.2fr .8fr .8fr;
      gap: 20px;
      align-items: start;
    }
    .footer-brand {
      display: inline-flex;
      align-items: center;
      gap: 12px;
      font-weight: 900;
      font-size: 1.05rem;
      margin-bottom: 10px;
    }
    .site-footer p {
      margin: 0;
      color: var(--muted);
    }
    .footer-title {
      margin: 0 0 12px;
      font-size: 1rem;
      color: var(--text);
    }
    .footer-links {
      display: grid;
      gap: 10px;
    }
    .footer-links a {
      color: var(--muted);
      transition: .22s ease;
    }
    .footer-links a:hover,
    .footer-links a:focus-visible {
      color: var(--primary-strong);
    }
    .footer-note {
      margin-top: 18px;
      color: var(--soft);
      font-size: .94rem;
    }

    .tag-row {
      display: flex;
      flex-wrap: wrap;
      gap: 10px;
      margin-top: 18px;
    }
    .tag-row .badge {
      background: rgba(255,255,255,.76);
      border-color: rgba(20,44,74,.08);
      color: var(--muted);
    }

    @media (max-width: 1100px) {
      .hero-grid,
      .feature-layout,
      .stats-shell,
      .latest-grid,
      .cta-wrap,
      .footer-grid {
        grid-template-columns: 1fr;
      }
      .stage-grid {
        grid-template-columns: 1fr;
      }
      .side-panel {
        position: static;
      }
      .plan-grid {
        grid-template-columns: repeat(2, minmax(0, 1fr));
      }
      .step-grid {
        grid-template-columns: repeat(2, minmax(0, 1fr));
      }
      .stats-grid {
        grid-template-columns: repeat(2, minmax(0, 1fr));
      }
      .site-search input {
        min-width: 180px;
      }
    }

    @media (max-width: 820px) {
      .site-header .inner {
        padding: 12px 0 14px;
      }
      .brand {
        width: 100%;
      }
      .site-nav {
        order: 3;
        justify-content: flex-start;
        overflow-x: auto;
        padding-bottom: 4px;
        scrollbar-width: none;
      }
      .site-nav::-webkit-scrollbar {
        display: none;
      }
      .header-tools {
        order: 2;
        margin-left: 0;
        width: 100%;
        flex-wrap: wrap;
      }
      .site-search {
        width: 100%;
      }
      .site-search input {
        min-width: 0;
        width: 100%;
      }
      .locale-switch {
        margin-left: auto;
      }
      .hero {
        padding-top: 26px;
      }
      .hero h1 {
        font-size: clamp(2rem, 10vw, 3.3rem);
      }
      .hero-stats {
        grid-template-columns: repeat(2, minmax(0, 1fr));
      }
      .plan-grid,
      .step-grid,
      .stats-grid {
        grid-template-columns: 1fr;
      }
      .section {
        padding: 58px 0;
      }
      .section-head {
        align-items: start;
        flex-direction: column;
      }
      .cta-panel,
      .update-panel,
      .feature-spot {
        border-radius: 26px;
      }
    }

    @media (max-width: 560px) {
      .container {
        width: min(var(--container), calc(100% - 24px));
      }
      .hero-stats {
        grid-template-columns: 1fr;
      }
      .hero-actions,
      .cta-actions {
        flex-direction: column;
      }
      .btn {
        width: 100%;
      }
      .feature-card.feature-small {
        grid-template-columns: 1fr;
      }
      .feature-icon {
        margin-bottom: 2px;
      }
      .mini-card {
        flex-direction: column;
        align-items: stretch;
      }
      .mini-chart {
        width: 100%;
      }
      .post-top {
        align-items: start;
      }
      .faq-details {
        padding: 0 14px;
      }
      .cta-panel,
      .update-panel,
      .post-card,
      .feature-card,
      .metric-card,
      .step-card,
      .plan-card {
        padding-left: 18px;
        padding-right: 18px;
      }
    }

/* roulang page: article */
:root{
      --bg: #f4f8fd;
      --bg-2: #eef4fb;
      --surface: rgba(255,255,255,.86);
      --surface-strong: #ffffff;
      --surface-soft: #f8fbff;
      --primary: #1d67d8;
      --primary-strong: #1550b4;
      --accent: #56bbff;
      --accent-2: #8ce0ff;
      --text: #12263a;
      --muted: #62778f;
      --soft: #8a9ab0;
      --border: rgba(20, 44, 74, .10);
      --border-strong: rgba(29,103,216,.20);
      --shadow: 0 18px 48px rgba(18, 38, 58, .08);
      --shadow-strong: 0 22px 60px rgba(18, 38, 58, .14);
      --radius-xl: 30px;
      --radius-lg: 24px;
      --radius-md: 18px;
      --radius-sm: 14px;
      --container: 1180px;
      --gap: 18px;
    }

    html {
      scroll-behavior: smooth;
      -webkit-text-size-adjust: 100%;
    }

    * {
      box-sizing: border-box;
    }

    body {
      margin: 0;
      color: var(--text);
      font-family: -apple-system, BlinkMacSystemFont, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Noto Sans CJK SC", sans-serif;
      line-height: 1.75;
      background:
        radial-gradient(circle at 0% 0%, rgba(29, 103, 216, .12) 0%, rgba(29, 103, 216, 0) 36%),
        radial-gradient(circle at 100% 0%, rgba(86, 187, 255, .10) 0%, rgba(86, 187, 255, 0) 32%),
        linear-gradient(180deg, #f8fbff 0%, #f4f8fd 34%, #edf4fb 100%);
      text-rendering: optimizeLegibility;
      -webkit-font-smoothing: antialiased;
    }

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

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

    button,
    input,
    select,
    textarea {
      font: inherit;
    }

    button {
      cursor: pointer;
    }

    ::selection {
      background: rgba(29, 103, 216, .18);
      color: var(--text);
    }

    .sr-only {
      position: absolute !important;
      width: 1px;
      height: 1px;
      padding: 0;
      margin: -1px;
      overflow: hidden;
      clip: rect(0, 0, 0, 0);
      white-space: nowrap;
      border: 0;
    }

    .container {
      width: min(var(--container), calc(100% - 32px));
      margin: 0 auto;
    }

    .site-header {
      position: sticky;
      top: 0;
      z-index: 50;
      backdrop-filter: blur(16px);
      -webkit-backdrop-filter: blur(16px);
      background: rgba(247, 251, 255, .78);
      border-bottom: 1px solid rgba(216, 228, 240, .72);
    }

    .site-header .inner {
      display: flex;
      align-items: center;
      gap: 14px;
      padding: 14px 0;
      flex-wrap: wrap;
    }

    .brand {
      display: inline-flex;
      align-items: center;
      gap: 12px;
      font-weight: 800;
      color: var(--text);
      letter-spacing: .2px;
      flex: 0 0 auto;
      white-space: nowrap;
    }

    .brand-mark {
      width: 40px;
      height: 40px;
      border-radius: 14px;
      display: grid;
      place-items: center;
      color: #fff;
      background: linear-gradient(135deg, var(--primary), var(--accent));
      box-shadow: 0 14px 28px rgba(29, 103, 216, .26);
      font-size: .84rem;
      letter-spacing: .08em;
    }

    .brand-text {
      font-size: 1.04rem;
    }

    .site-nav {
      display: flex;
      align-items: center;
      justify-content: center;
      gap: 10px;
      flex: 1 1 220px;
      min-width: 0;
    }

    .site-nav a {
      padding: 10px 16px;
      border-radius: 999px;
      color: var(--muted);
      border: 1px solid transparent;
      transition: .22s ease;
      white-space: nowrap;
      font-weight: 600;
    }

    .site-nav a:hover,
    .site-nav a:focus-visible,
    .site-nav a.active {
      background: rgba(29,103,216,.08);
      color: var(--primary-strong);
      border-color: rgba(29,103,216,.15);
      outline: none;
    }

    .header-tools {
      display: flex;
      align-items: center;
      gap: 10px;
      margin-left: auto;
      flex: 0 0 auto;
    }

    .site-search {
      display: flex;
      align-items: center;
      gap: 8px;
      padding: 7px 8px 7px 14px;
      border-radius: 999px;
      background: var(--surface-strong);
      border: 1px solid var(--border);
      box-shadow: var(--shadow);
      transition: .22s ease;
    }

    .site-search:focus-within {
      border-color: rgba(29,103,216,.24);
      box-shadow: 0 16px 40px rgba(18, 38, 58, .10);
      transform: translateY(-1px);
    }

    .site-search .icon {
      color: var(--soft);
      font-size: .95rem;
      line-height: 1;
    }

    .site-search input {
      border: 0;
      outline: 0;
      background: transparent;
      min-width: 230px;
      color: var(--text);
    }

    .site-search input::placeholder {
      color: #93a3b7;
    }

    .site-search button {
      border: 0;
      background: linear-gradient(135deg, var(--primary), #4aa4ff);
      color: #fff;
      font-weight: 700;
      border-radius: 999px;
      padding: 11px 16px;
      transition: .22s ease;
      box-shadow: 0 12px 24px rgba(29, 103, 216, .20);
    }

    .site-search button:hover {
      transform: translateY(-1px);
      box-shadow: 0 16px 28px rgba(29, 103, 216, .28);
    }

    .site-search button:active {
      transform: translateY(0);
    }

    .site-search input:focus-visible,
    .site-search button:focus-visible,
    .locale-switch .pill:focus-visible,
    .btn:focus-visible,
    .ghost-link:focus-visible,
    .toc-toggle:focus-visible,
    .floating-top:focus-visible,
    .card-link:focus-visible {
      outline: 3px solid rgba(86, 187, 255, .34);
      outline-offset: 2px;
    }

    .locale-switch {
      display: inline-flex;
      padding: 4px;
      border-radius: 999px;
      background: rgba(255,255,255,.82);
      border: 1px solid var(--border);
      box-shadow: var(--shadow);
    }

    .locale-switch .pill {
      border: 0;
      background: transparent;
      color: var(--muted);
      border-radius: 999px;
      padding: 9px 14px;
      transition: .22s ease;
      font-weight: 700;
      min-width: 68px;
    }

    .locale-switch .pill.active {
      color: var(--primary-strong);
      background: rgba(29,103,216,.10);
      box-shadow: inset 0 0 0 1px rgba(29,103,216,.12);
    }

    .locale-switch .pill:hover {
      color: var(--primary-strong);
    }

    main {
      display: block;
    }

    section {
      padding: 40px 0;
      scroll-margin-top: 94px;
    }

    .article-hero {
      padding-top: 34px;
      padding-bottom: 16px;
    }

    .article-hero .hero-wrap {
      position: relative;
      overflow: hidden;
      border: 1px solid rgba(255,255,255,.78);
      border-radius: var(--radius-xl);
      background:
        linear-gradient(180deg, rgba(255,255,255,.94), rgba(248,251,255,.86)),
        radial-gradient(circle at top right, rgba(86, 187, 255, .12), transparent 32%),
        radial-gradient(circle at bottom left, rgba(29, 103, 216, .08), transparent 34%);
      box-shadow: var(--shadow-strong);
      padding: 24px;
    }

    .breadcrumb-row {
      display: flex;
      align-items: center;
      justify-content: space-between;
      gap: 14px;
      margin-bottom: 18px;
      flex-wrap: wrap;
    }

    .breadcrumbs {
      display: flex;
      align-items: center;
      flex-wrap: wrap;
      gap: 8px;
      color: var(--muted);
      font-size: .95rem;
    }

    .breadcrumbs a {
      color: var(--muted);
      transition: .2s ease;
    }

    .breadcrumbs a:hover {
      color: var(--primary-strong);
    }

    .breadcrumbs .sep {
      color: #9fb0c4;
    }

    .ghost-link {
      display: inline-flex;
      align-items: center;
      gap: 8px;
      padding: 10px 14px;
      border-radius: 999px;
      background: rgba(29,103,216,.08);
      color: var(--primary-strong);
      border: 1px solid rgba(29,103,216,.14);
      font-weight: 700;
      transition: .22s ease;
    }

    .ghost-link:hover {
      transform: translateY(-1px);
      box-shadow: 0 12px 22px rgba(29, 103, 216, .10);
    }

    .article-hero-grid {
      display: grid;
      grid-template-columns: minmax(0, 1.32fr) minmax(300px, .68fr);
      gap: 20px;
      align-items: stretch;
    }

    .hero-panel,
    .info-panel,
    .article-box,
    .toc-panel,
    .rail-panel,
    .latest-box,
    .cta-panel,
    .empty-state {
      border: 1px solid var(--border);
      background: var(--surface);
      border-radius: var(--radius-lg);
      box-shadow: var(--shadow);
    }

    .hero-panel {
      padding: 26px;
      background:
        linear-gradient(180deg, rgba(255,255,255,.96), rgba(248,251,255,.90));
      position: relative;
      overflow: hidden;
    }

    .hero-panel::after {
      content: "";
      position: absolute;
      inset: auto -80px -90px auto;
      width: 240px;
      height: 240px;
      border-radius: 50%;
      background: radial-gradient(circle, rgba(86,187,255,.16) 0%, rgba(86,187,255,0) 68%);
      pointer-events: none;
    }

    .eyebrow {
      display: inline-flex;
      align-items: center;
      gap: 8px;
      border-radius: 999px;
      padding: 8px 14px;
      color: var(--primary-strong);
      background: rgba(29,103,216,.10);
      border: 1px solid rgba(29,103,216,.12);
      font-size: .92rem;
      font-weight: 700;
      letter-spacing: .02em;
    }

    .article-hero h1 {
      margin: 16px 0 12px;
      font-size: clamp(2rem, 4vw, 3.1rem);
      line-height: 1.18;
      letter-spacing: -.03em;
      color: var(--text);
    }

    .hero-lead {
      margin: 0;
      color: var(--muted);
      font-size: 1.04rem;
      max-width: 66ch;
    }

    .meta-row {
      display: flex;
      flex-wrap: wrap;
      gap: 10px;
      margin-top: 18px;
    }

    .chip {
      display: inline-flex;
      align-items: center;
      gap: 8px;
      padding: 9px 12px;
      border-radius: 999px;
      color: var(--primary-strong);
      background: rgba(29,103,216,.08);
      border: 1px solid rgba(29,103,216,.12);
      font-size: .92rem;
      font-weight: 700;
    }

    .chip.soft {
      color: var(--muted);
      background: rgba(255,255,255,.72);
      border-color: var(--border);
    }

    .hero-actions {
      display: flex;
      flex-wrap: wrap;
      gap: 12px;
      margin-top: 22px;
    }

    .btn {
      display: inline-flex;
      align-items: center;
      justify-content: center;
      gap: 8px;
      min-height: 46px;
      padding: 0 18px;
      border-radius: 999px;
      border: 1px solid transparent;
      font-weight: 700;
      transition: .22s ease;
      user-select: none;
      white-space: nowrap;
    }

    .btn-primary {
      color: #fff;
      background: linear-gradient(135deg, var(--primary), #4aa4ff);
      box-shadow: 0 14px 26px rgba(29,103,216,.20);
    }

    .btn-primary:hover {
      transform: translateY(-1px);
      box-shadow: 0 18px 30px rgba(29,103,216,.26);
      background: linear-gradient(135deg, var(--primary-strong), #3a97f3);
    }

    .btn-secondary {
      color: var(--primary-strong);
      background: rgba(255,255,255,.92);
      border-color: rgba(29,103,216,.15);
    }

    .btn-secondary:hover {
      transform: translateY(-1px);
      border-color: rgba(29,103,216,.24);
      box-shadow: 0 12px 24px rgba(18, 38, 58, .08);
      color: var(--primary-strong);
    }

    .info-panel {
      padding: 20px;
      display: grid;
      gap: 14px;
      align-content: start;
      background:
        linear-gradient(180deg, rgba(248,251,255,.95), rgba(255,255,255,.90));
    }

    .panel-title {
      display: flex;
      align-items: center;
      justify-content: space-between;
      gap: 10px;
    }

    .panel-kicker {
      font-size: .88rem;
      color: var(--soft);
      font-weight: 700;
      letter-spacing: .04em;
      text-transform: uppercase;
    }

    .info-title {
      margin: 0;
      font-size: 1.14rem;
      line-height: 1.35;
    }

    .info-list {
      display: grid;
      gap: 12px;
    }

    .info-item {
      display: flex;
      align-items: flex-start;
      gap: 12px;
      padding: 12px 14px;
      border-radius: var(--radius-md);
      border: 1px solid rgba(29,103,216,.10);
      background: rgba(255,255,255,.82);
    }

    .info-icon {
      width: 36px;
      height: 36px;
      border-radius: 12px;
      display: grid;
      place-items: center;
      color: var(--primary-strong);
      background: rgba(29,103,216,.10);
      flex: 0 0 auto;
      font-size: 1rem;
    }

    .info-item strong {
      display: block;
      margin-bottom: 2px;
      font-size: .98rem;
    }

    .info-item span {
      display: block;
      color: var(--muted);
      font-size: .92rem;
      line-height: 1.6;
    }

    .article-shell {
      padding-top: 16px;
    }

    .article-grid {
      display: grid;
      grid-template-columns: 240px minmax(0, 1fr) 300px;
      gap: 18px;
      align-items: start;
    }

    .toc-panel {
      position: sticky;
      top: 96px;
      padding: 18px;
      align-self: start;
      max-height: calc(100vh - 120px);
      overflow: auto;
    }

    .toc-head {
      display: flex;
      align-items: flex-start;
      justify-content: space-between;
      gap: 10px;
      margin-bottom: 12px;
    }

    .toc-head h2 {
      margin: 3px 0 0;
      font-size: 1.04rem;
      line-height: 1.4;
    }

    .toc-toggle {
      display: none;
      border: 1px solid rgba(29,103,216,.14);
      background: rgba(29,103,216,.06);
      color: var(--primary-strong);
      border-radius: 999px;
      padding: 8px 12px;
      font-weight: 700;
      transition: .22s ease;
    }

    .toc-toggle:hover {
      background: rgba(29,103,216,.10);
    }

    .toc-list {
      display: grid;
      gap: 8px;
    }

    .toc-link {
      display: block;
      padding: 10px 12px;
      border-radius: 12px;
      color: var(--muted);
      border: 1px solid transparent;
      background: rgba(255,255,255,.58);
      line-height: 1.55;
      transition: .2s ease;
      font-size: .95rem;
    }

    .toc-link:hover,
    .toc-link.active {
      color: var(--primary-strong);
      border-color: rgba(29,103,216,.14);
      background: rgba(29,103,216,.08);
      transform: translateX(2px);
    }

    .toc-link.depth-3 {
      padding-left: 18px;
      font-size: .92rem;
    }

    .toc-empty {
      color: var(--soft);
      font-size: .95rem;
      padding: 12px;
      border-radius: 12px;
      background: rgba(255,255,255,.64);
      border: 1px dashed rgba(29,103,216,.14);
    }

    .article-box {
      padding: 22px;
      min-width: 0;
    }

    .article-topline {
      display: flex;
      flex-wrap: wrap;
      align-items: center;
      justify-content: space-between;
      gap: 12px;
      padding-bottom: 16px;
      margin-bottom: 18px;
      border-bottom: 1px solid var(--border);
    }

    .article-meta {
      display: flex;
      flex-wrap: wrap;
      gap: 10px;
    }

    .meta-pill {
      display: inline-flex;
      align-items: center;
      gap: 8px;
      padding: 8px 12px;
      border-radius: 999px;
      background: rgba(248,251,255,.94);
      border: 1px solid var(--border);
      color: var(--muted);
      font-size: .92rem;
    }

    .meta-pill strong {
      color: var(--primary-strong);
    }

    .article-content {
      color: var(--text);
      font-size: 1.03rem;
      line-height: 1.92;
      overflow: hidden;
    }

    .article-content :first-child {
      margin-top: 0;
    }

    .article-content h2,
    .article-content h3,
    .article-content h4 {
      margin: 2.0em 0 .9em;
      line-height: 1.35;
      letter-spacing: -.02em;
      color: var(--text);
      scroll-margin-top: 104px;
    }

    .article-content h2 {
      font-size: 1.48rem;
      padding-bottom: 12px;
      border-bottom: 1px solid rgba(29,103,216,.12);
    }

    .article-content h3 {
      font-size: 1.2rem;
    }

    .article-content p {
      margin: 1em 0;
      color: var(--text);
    }

    .article-content a {
      color: var(--primary-strong);
      text-decoration: none;
      border-bottom: 1px solid rgba(29,103,216,.22);
      transition: .2s ease;
    }

    .article-content a:hover {
      color: var(--primary);
      border-bottom-color: rgba(29,103,216,.42);
    }

    .article-content ul,
    .article-content ol {
      margin: 1em 0;
      padding-left: 1.35em;
    }

    .article-content li {
      margin: .45em 0;
    }

    .article-content blockquote {
      margin: 1.4em 0;
      padding: 16px 18px;
      border-radius: 18px;
      border-left: 4px solid var(--primary);
      background: linear-gradient(180deg, rgba(29,103,216,.06), rgba(255,255,255,.86));
      color: var(--muted);
      box-shadow: inset 0 0 0 1px rgba(29,103,216,.08);
    }

    .article-content code {
      padding: .18em .42em;
      border-radius: 8px;
      background: rgba(29,103,216,.09);
      color: #173f7a;
      font-size: .94em;
    }

    .article-content pre {
      margin: 1.2em 0;
      overflow: auto;
      padding: 16px 18px;
      border-radius: 18px;
      background: #0f1f31;
      color: #eaf2ff;
      box-shadow: inset 0 0 0 1px rgba(255,255,255,.06);
    }

    .article-content pre code {
      padding: 0;
      background: transparent;
      color: inherit;
      font-size: .95rem;
    }

    .article-content table {
      width: 100%;
      border-collapse: collapse;
      margin: 1.2em 0;
      overflow: hidden;
      border-radius: 16px;
      display: block;
    }

    .article-content table thead,
    .article-content table tbody {
      display: table;
      width: 100%;
      table-layout: fixed;
    }

    .article-content th,
    .article-content td {
      border: 1px solid rgba(20,44,74,.10);
      padding: 12px 14px;
      text-align: left;
      background: rgba(255,255,255,.76);
      vertical-align: top;
    }

    .article-content th {
      background: rgba(29,103,216,.06);
      font-weight: 700;
    }

    .article-content img {
      margin: 1.35em auto;
      border-radius: 18px;
      box-shadow: var(--shadow);
      border: 1px solid rgba(20,44,74,.08);
    }

    .article-content hr {
      border: 0;
      height: 1px;
      background: linear-gradient(90deg, transparent, rgba(29,103,216,.20), transparent);
      margin: 1.5em 0;
    }

    .article-end {
      margin-top: 26px;
      padding-top: 18px;
      border-top: 1px solid var(--border);
    }

    .return-grid {
      display: grid;
      grid-template-columns: repeat(3, minmax(0, 1fr));
      gap: 12px;
    }

    .return-card {
      display: block;
      padding: 16px;
      border-radius: 18px;
      border: 1px solid var(--border);
      background: linear-gradient(180deg, rgba(255,255,255,.92), rgba(248,251,255,.84));
      transition: .22s ease;
      box-shadow: 0 12px 28px rgba(18, 38, 58, .05);
    }

    .return-card:hover {
      transform: translateY(-2px);
      border-color: rgba(29,103,216,.18);
      box-shadow: 0 18px 34px rgba(18, 38, 58, .08);
    }

    .return-card .label {
      display: inline-flex;
      align-items: center;
      gap: 8px;
      color: var(--primary-strong);
      font-weight: 700;
      font-size: .92rem;
    }

    .return-card h3 {
      margin: 10px 0 6px;
      font-size: 1.06rem;
      line-height: 1.4;
    }

    .return-card p {
      margin: 0;
      color: var(--muted);
      font-size: .94rem;
      line-height: 1.7;
    }

    .side-rail {
      position: sticky;
      top: 96px;
      display: grid;
      gap: 16px;
      align-self: start;
    }

    .rail-panel {
      padding: 18px;
    }

    .rail-title {
      margin: 0 0 10px;
      font-size: 1.04rem;
      line-height: 1.35;
    }

    .rail-text {
      margin: 0;
      color: var(--muted);
      font-size: .95rem;
      line-height: 1.75;
    }

    .quick-links {
      display: grid;
      gap: 10px;
      margin-top: 12px;
    }

    .quick-link {
      display: flex;
      align-items: center;
      justify-content: space-between;
      gap: 12px;
      padding: 12px 14px;
      border-radius: 14px;
      background: rgba(255,255,255,.76);
      border: 1px solid var(--border);
      transition: .2s ease;
      color: var(--text);
    }

    .quick-link:hover {
      transform: translateY(-1px);
      border-color: rgba(29,103,216,.16);
      box-shadow: 0 10px 20px rgba(18, 38, 58, .06);
    }

    .quick-link .arrow {
      color: var(--primary-strong);
      font-weight: 700;
    }

    .mini-stats {
      display: grid;
      grid-template-columns: repeat(2, minmax(0, 1fr));
      gap: 10px;
    }

    .stat {
      padding: 14px;
      border-radius: 16px;
      background: rgba(255,255,255,.80);
      border: 1px solid var(--border);
    }

    .stat .num {
      display: block;
      font-size: 1.16rem;
      font-weight: 800;
      color: var(--primary-strong);
      line-height: 1.2;
    }

    .stat .txt {
      display: block;
      margin-top: 5px;
      color: var(--muted);
      font-size: .9rem;
      line-height: 1.5;
    }

    .latest-section {
      padding-top: 10px;
    }

    .latest-box {
      padding: 22px;
      overflow: hidden;
    }

    .section-head {
      display: flex;
      align-items: end;
      justify-content: space-between;
      gap: 12px;
      margin-bottom: 18px;
      flex-wrap: wrap;
    }

    .section-head h2 {
      margin: 0;
      font-size: 1.42rem;
      line-height: 1.25;
      letter-spacing: -.02em;
    }

    .section-head p {
      margin: 0;
      color: var(--muted);
      font-size: .96rem;
    }

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

    .latest-card {
      display: grid;
      gap: 12px;
      padding: 16px;
      border-radius: 18px;
      background: linear-gradient(180deg, rgba(255,255,255,.95), rgba(248,251,255,.82));
      border: 1px solid var(--border);
      transition: .22s ease;
      min-height: 100%;
    }

    .latest-card:hover {
      transform: translateY(-2px);
      border-color: rgba(29,103,216,.18);
      box-shadow: 0 18px 30px rgba(18, 38, 58, .07);
    }

    .latest-thumb {
      aspect-ratio: 16 / 9;
      border-radius: 16px;
      background:
        radial-gradient(circle at 30% 30%, rgba(86,187,255,.58), rgba(86,187,255,0) 34%),
        linear-gradient(135deg, rgba(29,103,216,.90), rgba(86,187,255,.80));
      position: relative;
      overflow: hidden;
    }

    .latest-thumb::after {
      content: "BT";
      position: absolute;
      right: 12px;
      bottom: 10px;
      color: rgba(255,255,255,.88);
      font-weight: 800;
      font-size: 1rem;
      letter-spacing: .08em;
    }

    .latest-card h3 {
      margin: 0;
      font-size: 1.02rem;
      line-height: 1.45;
    }

    .latest-card p {
      margin: 0;
      color: var(--muted);
      font-size: .94rem;
      line-height: 1.7;
    }

    .card-meta {
      display: flex;
      flex-wrap: wrap;
      gap: 8px;
      color: var(--soft);
      font-size: .86rem;
    }

    .card-link {
      display: inline-flex;
      align-items: center;
      gap: 8px;
      font-weight: 700;
      color: var(--primary-strong);
      margin-top: auto;
    }

    .card-link .arrow {
      transition: transform .2s ease;
    }

    .latest-card:hover .card-link .arrow {
      transform: translateX(2px);
    }

    .empty-latest {
      padding: 20px;
      border-radius: 18px;
      border: 1px dashed rgba(29,103,216,.18);
      background: rgba(255,255,255,.72);
      color: var(--muted);
    }

    .footer-spacer {
      height: 8px;
    }

    .cta-panel {
      padding: 22px;
      background:
        linear-gradient(135deg, rgba(29,103,216,.10), rgba(255,255,255,.88)),
        radial-gradient(circle at top right, rgba(86,187,255,.14), transparent 34%);
    }

    .cta-panel h2 {
      margin: 0 0 8px;
      font-size: 1.34rem;
      line-height: 1.3;
    }

    .cta-panel p {
      margin: 0;
      color: var(--muted);
      max-width: 70ch;
    }

    .cta-actions {
      display: flex;
      flex-wrap: wrap;
      gap: 12px;
      margin-top: 16px;
    }

    .site-footer {
      padding: 28px 0 40px;
    }

    .footer-grid {
      display: grid;
      grid-template-columns: 1.35fr .85fr 1fr;
      gap: 18px;
      border-top: 1px solid rgba(20,44,74,.08);
      padding-top: 22px;
    }

    .footer-brand {
      display: inline-flex;
      align-items: center;
      gap: 12px;
      font-weight: 800;
      margin-bottom: 12px;
      white-space: nowrap;
    }

    .footer-brand .brand-mark {
      width: 38px;
      height: 38px;
      border-radius: 14px;
      font-size: .82rem;
    }

    .footer-title {
      margin: 0 0 12px;
      font-size: 1.02rem;
    }

    .footer-links {
      display: grid;
      gap: 10px;
    }

    .footer-links a {
      color: var(--muted);
      transition: .2s ease;
      width: fit-content;
    }

    .footer-links a:hover {
      color: var(--primary-strong);
      transform: translateX(2px);
    }

    .footer-note {
      margin-top: 14px;
      color: var(--soft);
      font-size: .92rem;
    }

    .site-footer p {
      margin: 0;
      color: var(--muted);
      line-height: 1.8;
    }

    .floating-top {
      position: fixed;
      right: 18px;
      bottom: 18px;
      width: 48px;
      height: 48px;
      border-radius: 16px;
      display: grid;
      place-items: center;
      background: var(--surface-strong);
      border: 1px solid var(--border);
      box-shadow: var(--shadow);
      color: var(--primary-strong);
      z-index: 40;
      transition: .22s ease;
    }

    .floating-top:hover {
      transform: translateY(-2px);
      box-shadow: var(--shadow-strong);
    }

    .empty-state {
      padding: 28px;
      text-align: center;
      background:
        linear-gradient(180deg, rgba(255,255,255,.94), rgba(248,251,255,.86));
    }

    .empty-state h2 {
      margin: 0 0 10px;
      font-size: 1.42rem;
    }

    .empty-state p {
      margin: 0 auto 18px;
      color: var(--muted);
      max-width: 56ch;
    }

    .content-gap {
      margin-top: 22px;
    }

    @media (max-width: 1180px) {
      .article-grid {
        grid-template-columns: 220px minmax(0, 1fr);
      }

      .side-rail {
        grid-column: 1 / -1;
        position: static;
        grid-template-columns: repeat(2, minmax(0, 1fr));
      }

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

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

    @media (max-width: 1024px) {
      .site-search input {
        min-width: 180px;
      }

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

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

      .toc-panel {
        position: relative;
        top: 0;
        max-height: none;
      }

      .toc-toggle {
        display: inline-flex;
      }

      .toc-list {
        display: none;
      }

      .toc-panel.open .toc-list {
        display: grid;
      }

      .side-rail {
        grid-template-columns: 1fr 1fr;
      }

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

    @media (max-width: 768px) {
      .site-header .inner {
        gap: 10px;
      }

      .site-nav {
        order: 3;
        width: 100%;
        justify-content: flex-start;
        overflow-x: auto;
        padding-bottom: 2px;
      }

      .header-tools {
        width: 100%;
        justify-content: space-between;
      }

      .site-search {
        width: 100%;
      }

      .site-search input {
        min-width: 0;
        width: 100%;
      }

      .locale-switch {
        flex: 0 0 auto;
      }

      .hero-panel,
      .info-panel,
      .article-box,
      .toc-panel,
      .rail-panel,
      .latest-box,
      .cta-panel {
        padding: 18px;
      }

      .article-hero h1 {
        font-size: clamp(1.8rem, 7vw, 2.4rem);
      }

      .article-content {
        font-size: 1rem;
      }

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

      .side-rail {
        grid-template-columns: 1fr;
      }

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

    @media (max-width: 520px) {
      .container {
        width: min(var(--container), calc(100% - 22px));
      }

      .site-search {
        padding-left: 12px;
      }

      .site-search button {
        padding: 10px 14px;
      }

      .hero-actions,
      .cta-actions {
        flex-direction: column;
      }

      .btn {
        width: 100%;
      }

      .meta-row,
      .article-meta {
        gap: 8px;
      }

      .chip,
      .meta-pill {
        width: 100%;
        justify-content: center;
      }

      .breadcrumb-row {
        align-items: flex-start;
      }

      .hero-panel,
      .info-panel,
      .article-box,
      .toc-panel,
      .rail-panel,
      .latest-box,
      .cta-panel,
      .empty-state {
        border-radius: 20px;
      }

      .floating-top {
        right: 14px;
        bottom: 14px;
      }
    }