.presentation-shell {
  --presentation-ink: #0b1730;
  --presentation-navy: #0a1630;
  --presentation-blue: #2f6fed;
  /* 图形对象用的深一档蓝: --presentation-blue 压在 .scope-notice 的浅蓝底上只有 4.11:1,
     对图标 (非文本) 虽已过 1.4.11 的 3:1, 但同一处的锁形图标与正文一起读时偏淡, 因此另立一档
     (对同一底 6.08:1); 原色保留给渐变与描边使用. */
  --presentation-blue-strong: #2458b3;
  --presentation-line: rgba(15, 35, 70, 0.1);
  --presentation-shadow: 0 18px 46px rgba(15, 35, 70, 0.08);
  background:
    radial-gradient(circle at 82% -12%, rgba(47, 111, 237, 0.1), transparent 31rem),
    #f3f6fb;
}

.presentation-shell .sidebar {
  background:
    radial-gradient(circle at 12% 4%, rgba(70, 137, 255, 0.24), transparent 15rem),
    linear-gradient(180deg, #0c1b38 0%, var(--presentation-navy) 58%, #081226 100%);
  border-right: 1px solid rgba(139, 176, 255, 0.16);
  box-shadow: 18px 0 44px rgba(6, 18, 39, 0.14);
}

.presentation-shell .topbar {
  min-height: 68px;
  gap: 18px;
  background: rgba(255, 255, 255, 0.93);
  border-bottom-color: var(--presentation-line);
  box-shadow: 0 8px 28px rgba(15, 35, 70, 0.05);
  backdrop-filter: blur(16px);
}

.presentation-shell .study-context {
  min-width: 0;
  gap: 3px;
}

.presentation-shell .study-context .context-label {
  /* 旧值 #73809a 对近白顶栏只有 3.94:1 (axe 因 backdrop-filter 只能报 incomplete, 人工测量);
     #5f6a80 对白 5.44 / 对页面底 #f3f6fb 5.02 / 对 --edf3ff 4.89. */
  color: #5f6a80;
  font-size: 10px;
  font-weight: 750;
  letter-spacing: 0.08em;
}

.presentation-shell .study-context .study-selector {
  min-width: 0;
  color: var(--presentation-ink);
  font-weight: 720;
}

.presentation-shell .surface-indicator {
  min-height: 32px;
  padding-inline: 11px;
  color: #2458b3;
  background: #edf3ff;
  border-color: #d7e4ff;
  border-radius: 999px;
}

.presentation-shell .scope-notice {
  min-height: 40px;
  padding-block: 8px;
  color: #244d92;
  background: linear-gradient(90deg, #edf4ff 0%, #f5f8ff 62%, #eef5ff 100%);
  border-bottom-color: #d9e5fa;
}

.presentation-shell .scope-notice .icon {
  color: var(--presentation-blue-strong);
}

.presentation-shell .workspace {
  width: min(100%, 1540px);
  padding-top: 28px;
}

.presentation-shell .overview-insight-stack {
  grid-template-columns: minmax(0, 1fr);
}

.presentation-shell .page-heading {
  position: relative;
  align-items: center;
  min-height: 112px;
  margin-bottom: 22px;
  padding: 22px 24px 22px 27px;
  overflow: hidden;
  background: rgba(255, 255, 255, 0.96);
  border: 1px solid var(--presentation-line);
  border-radius: 14px;
  box-shadow: var(--presentation-shadow);
}

.presentation-shell .page-heading::before {
  position: absolute;
  inset: 0 auto 0 0;
  width: 4px;
  content: "";
  background: linear-gradient(180deg, #4b85f7 0%, #235eca 100%);
}

.presentation-shell .page-heading > div:first-child {
  min-width: 0;
}

.presentation-shell .page-heading .breadcrumb {
  margin-bottom: 7px;
  /* 旧值 #74829a 对近白卡片只有 3.86:1; #5f6a80 = 5.44:1 (同 context-label 一个口径). */
  color: #5f6a80;
  font-weight: 650;
}

.presentation-shell .page-heading h1 {
  margin-bottom: 6px;
  color: var(--presentation-ink);
  font-size: clamp(23px, 2vw, 29px);
  font-weight: 760;
  letter-spacing: -0.025em;
}

.presentation-shell .page-heading p {
  max-width: 76ch;
  color: #647089;
  line-height: 1.65;
}

.presentation-shell button:focus-visible,
.presentation-shell input:focus-visible,
.presentation-shell select:focus-visible,
.presentation-shell [tabindex]:focus-visible {
  outline: 3px solid #1d4ed8;
  outline-offset: 3px;
  box-shadow: 0 0 0 2px #ffffff;
}

@media (max-width: 880px) {
  .presentation-shell .sidebar {
    box-shadow: 20px 0 54px rgba(6, 18, 39, 0.28);
  }

  .presentation-shell .topbar {
    gap: 11px;
  }
}

@media (max-width: 640px) {
  .presentation-shell .topbar {
    min-height: 64px;
    align-items: center;
    flex-wrap: wrap;
    padding-block: 9px;
  }

  .presentation-shell .study-context {
    flex: 1 1 160px;
  }

  .presentation-shell .study-context .study-selector {
    max-width: min(52vw, 220px);
  }

  .presentation-shell .surface-indicator {
    max-width: 38vw;
  }

  .presentation-shell .surface-indicator span,
  .presentation-shell .study-context .study-selector span {
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
  }

  .presentation-shell .scope-notice {
    align-items: flex-start;
    line-height: 1.55;
  }

  .presentation-shell .scope-notice .icon {
    margin-top: 2px;
  }

  .presentation-shell .workspace {
    padding-top: 18px;
  }

  .presentation-shell .page-heading {
    min-height: 0;
    gap: 14px;
    margin-bottom: 16px;
    padding: 19px 17px 18px 20px;
    border-radius: 12px;
  }

  .presentation-shell .page-heading .page-actions {
    flex-wrap: wrap;
  }
}

@media (max-width: 480px) {
  .presentation-shell .topbar {
    display: grid;
    grid-template-columns: 44px minmax(0, 1fr) auto;
    gap: 8px;
    padding: 8px 12px;
  }

  .presentation-shell .mobile-menu,
  .presentation-shell .sidebar-close {
    width: 44px;
    height: 44px;
  }

  .presentation-shell .study-context,
  .presentation-shell .topbar-actions {
    min-width: 0;
  }

  .presentation-shell .study-context .context-label {
    font-size: 11px;
  }

  .presentation-shell .study-context .study-selector {
    max-width: 100%;
  }

  .presentation-shell .surface-indicator {
    max-width: 112px;
  }

  .presentation-shell .scope-notice {
    padding: 9px 12px;
    font-size: 13px;
  }

  .presentation-shell .page-heading {
    padding: 17px 14px 16px 17px;
  }

  .presentation-shell .page-heading p {
    font-size: 14px;
  }

  .presentation-shell .page-heading .page-actions {
    display: grid;
    grid-template-columns: minmax(0, 1fr);
    align-items: stretch;
  }

  .presentation-shell .page-heading .page-actions .button {
    min-width: 0;
    min-height: 44px;
    white-space: normal;
  }
}