/* Landing-like corner controls across app pages */
body.tree-viewer-page:not(.focus-mode),
body.dashboard-page:not(.focus-mode),
body.editor-page:not(.focus-mode),
body.auth-page:not(.focus-mode),
body.contact-page-layout:not(.focus-mode) {
  --floating-header-space: 80px;
  --corner-controls-top: 24px;
  --corner-controls-inset: 24px;
  --corner-control-size: 48px;
}

body.tree-viewer-page:not(.focus-mode) .topbar,
body.dashboard-page:not(.focus-mode) .topbar,
body.editor-page:not(.focus-mode) .topbar,
body.auth-page:not(.focus-mode) .topbar,
body.contact-page-layout:not(.focus-mode) .topbar {
  position: relative;
  height: var(--floating-header-space);
  min-height: var(--floating-header-space);
  margin: 0;
  padding: 0;
  border: 0;
  background: transparent;
  box-shadow: none;
  backdrop-filter: none;
  display: block;
  z-index: 7;
  pointer-events: none;
  overflow: visible;
}

body.tree-viewer-page:not(.focus-mode) .brand-group,
body.dashboard-page:not(.focus-mode) .brand-group,
body.editor-page:not(.focus-mode) .brand-group,
body.auth-page:not(.focus-mode) .brand-group,
body.contact-page-layout:not(.focus-mode) .brand-group {
  position: fixed;
  top: var(--corner-controls-top);
  left: var(--corner-controls-inset);
  z-index: 8;
  width: auto;
  min-width: 48px;
  padding: 0;
  display: flex;
  flex: 0 0 auto;
  align-items: center;
  justify-content: flex-start;
  pointer-events: auto;
}

body.tree-viewer-page:not(.focus-mode) .brand-group #themeBtn,
body.dashboard-page:not(.focus-mode) .brand-group #themeBtn,
body.editor-page:not(.focus-mode) .brand-group #themeBtn,
body.auth-page:not(.focus-mode) .brand-group #themeBtn,
body.contact-page-layout:not(.focus-mode) .brand-group #themeBtn {
  position: static;
  transform: none;
  margin: 0;
  width: var(--corner-control-size);
  height: var(--corner-control-size);
  min-width: var(--corner-control-size);
  min-height: var(--corner-control-size);
  border-radius: var(--radius-control);
  background: var(--surface);
}

/* Keep corner controls visually identical to landing page controls. */
body.tree-viewer-page:not(.focus-mode) .brand-group #themeBtn,
body.dashboard-page:not(.focus-mode) .brand-group #themeBtn,
body.editor-page:not(.focus-mode) .brand-group #themeBtn,
body.auth-page:not(.focus-mode) .brand-group #themeBtn,
body.contact-page-layout:not(.focus-mode) .brand-group #themeBtn,
body.tree-viewer-page:not(.focus-mode) .controls .icon-btn,
body.dashboard-page:not(.focus-mode) .controls .icon-btn,
body.editor-page:not(.focus-mode) .controls .icon-btn,
body.auth-page:not(.focus-mode) .controls .icon-btn,
body.contact-page-layout:not(.focus-mode) .controls .icon-btn,
body.tree-viewer-page:not(.focus-mode) #backBtn,
body.dashboard-page:not(.focus-mode) #backBtn,
body.editor-page:not(.focus-mode) #backBtn,
body.auth-page:not(.focus-mode) #backBtn,
body.contact-page-layout:not(.focus-mode) #backBtn {
  border: 1px solid rgba(0, 0, 0, 0.08);
  background: #ffffff;
  color: #1f2937;
  box-shadow: 0 2px 6px rgba(15, 23, 42, 0.08);
  transition: transform var(--transition-base) ease, box-shadow var(--transition-base) ease, border-color var(--transition-base) ease, background var(--transition-base) ease, color var(--transition-base) ease;
  position: relative;
  overflow: hidden;
  isolation: isolate;
}

body.tree-viewer-page:not(.focus-mode) .brand-group #themeBtn::after,
body.dashboard-page:not(.focus-mode) .brand-group #themeBtn::after,
body.editor-page:not(.focus-mode) .brand-group #themeBtn::after,
body.auth-page:not(.focus-mode) .brand-group #themeBtn::after,
body.contact-page-layout:not(.focus-mode) .brand-group #themeBtn::after,
body.tree-viewer-page:not(.focus-mode) #backBtn::after,
body.dashboard-page:not(.focus-mode) #backBtn::after,
body.editor-page:not(.focus-mode) #backBtn::after,
body.auth-page:not(.focus-mode) #backBtn::after,
body.contact-page-layout:not(.focus-mode) #backBtn::after {
  content: none;
}

body.tree-viewer-page:not(.focus-mode) .brand-group #themeBtn::before,
body.dashboard-page:not(.focus-mode) .brand-group #themeBtn::before,
body.editor-page:not(.focus-mode) .brand-group #themeBtn::before,
body.auth-page:not(.focus-mode) .brand-group #themeBtn::before,
body.contact-page-layout:not(.focus-mode) .brand-group #themeBtn::before,
body.tree-viewer-page:not(.focus-mode) .controls .icon-btn::before,
body.dashboard-page:not(.focus-mode) .controls .icon-btn::before,
body.editor-page:not(.focus-mode) .controls .icon-btn::before,
body.auth-page:not(.focus-mode) .controls .icon-btn::before,
body.contact-page-layout:not(.focus-mode) .controls .icon-btn::before,
body.tree-viewer-page:not(.focus-mode) #backBtn::before,
body.dashboard-page:not(.focus-mode) #backBtn::before,
body.editor-page:not(.focus-mode) #backBtn::before,
body.auth-page:not(.focus-mode) #backBtn::before,
body.contact-page-layout:not(.focus-mode) #backBtn::before {
  content: "";
  position: absolute;
  inset: 0;
  background: var(--gradient-primary);
  opacity: 0;
  transition: opacity var(--transition-base) ease;
  pointer-events: none;
  z-index: 0;
}

body.tree-viewer-page:not(.focus-mode) .brand-group #themeBtn > *,
body.dashboard-page:not(.focus-mode) .brand-group #themeBtn > *,
body.editor-page:not(.focus-mode) .brand-group #themeBtn > *,
body.auth-page:not(.focus-mode) .brand-group #themeBtn > *,
body.contact-page-layout:not(.focus-mode) .brand-group #themeBtn > *,
body.tree-viewer-page:not(.focus-mode) .controls .icon-btn > *,
body.dashboard-page:not(.focus-mode) .controls .icon-btn > *,
body.editor-page:not(.focus-mode) .controls .icon-btn > *,
body.auth-page:not(.focus-mode) .controls .icon-btn > *,
body.contact-page-layout:not(.focus-mode) .controls .icon-btn > *,
body.tree-viewer-page:not(.focus-mode) #backBtn > *,
body.dashboard-page:not(.focus-mode) #backBtn > *,
body.editor-page:not(.focus-mode) #backBtn > *,
body.auth-page:not(.focus-mode) #backBtn > *,
body.contact-page-layout:not(.focus-mode) #backBtn > * {
  position: relative;
  z-index: 1;
}

body.tree-viewer-page:not(.focus-mode) .brand-group #themeBtn:hover::before,
body.dashboard-page:not(.focus-mode) .brand-group #themeBtn:hover::before,
body.editor-page:not(.focus-mode) .brand-group #themeBtn:hover::before,
body.auth-page:not(.focus-mode) .brand-group #themeBtn:hover::before,
body.contact-page-layout:not(.focus-mode) .brand-group #themeBtn:hover::before,
body.tree-viewer-page:not(.focus-mode) .controls .icon-btn:hover::before,
body.dashboard-page:not(.focus-mode) .controls .icon-btn:hover::before,
body.editor-page:not(.focus-mode) .controls .icon-btn:hover::before,
body.auth-page:not(.focus-mode) .controls .icon-btn:hover::before,
body.contact-page-layout:not(.focus-mode) .controls .icon-btn:hover::before,
body.tree-viewer-page:not(.focus-mode) #backBtn:hover::before,
body.dashboard-page:not(.focus-mode) #backBtn:hover::before,
body.editor-page:not(.focus-mode) #backBtn:hover::before,
body.auth-page:not(.focus-mode) #backBtn:hover::before,
body.contact-page-layout:not(.focus-mode) #backBtn:hover::before {
  opacity: 0.08;
}

body.tree-viewer-page:not(.focus-mode) .brand-group #themeBtn:hover,
body.dashboard-page:not(.focus-mode) .brand-group #themeBtn:hover,
body.editor-page:not(.focus-mode) .brand-group #themeBtn:hover,
body.auth-page:not(.focus-mode) .brand-group #themeBtn:hover,
body.contact-page-layout:not(.focus-mode) .brand-group #themeBtn:hover,
body.tree-viewer-page:not(.focus-mode) .controls .icon-btn:hover,
body.dashboard-page:not(.focus-mode) .controls .icon-btn:hover,
body.editor-page:not(.focus-mode) .controls .icon-btn:hover,
body.auth-page:not(.focus-mode) .controls .icon-btn:hover,
body.contact-page-layout:not(.focus-mode) .controls .icon-btn:hover,
body.tree-viewer-page:not(.focus-mode) #backBtn:hover,
body.dashboard-page:not(.focus-mode) #backBtn:hover,
body.editor-page:not(.focus-mode) #backBtn:hover,
body.auth-page:not(.focus-mode) #backBtn:hover,
body.contact-page-layout:not(.focus-mode) #backBtn:hover {
  background: #ffffff;
  color: #1f2937;
  transform: translateY(-1px);
  box-shadow: 0 12px 24px rgba(15, 23, 42, 0.12);
  border-color: #3b82f6;
}

body.theme-dark.tree-viewer-page:not(.focus-mode) .brand-group #themeBtn:hover,
body.theme-dark.dashboard-page:not(.focus-mode) .brand-group #themeBtn:hover,
body.theme-dark.editor-page:not(.focus-mode) .brand-group #themeBtn:hover,
body.theme-dark.auth-page:not(.focus-mode) .brand-group #themeBtn:hover,
body.theme-dark.contact-page-layout:not(.focus-mode) .brand-group #themeBtn:hover,
body.theme-dark.tree-viewer-page:not(.focus-mode) .controls .icon-btn:hover,
body.theme-dark.dashboard-page:not(.focus-mode) .controls .icon-btn:hover,
body.theme-dark.editor-page:not(.focus-mode) .controls .icon-btn:hover,
body.theme-dark.auth-page:not(.focus-mode) .controls .icon-btn:hover,
body.theme-dark.contact-page-layout:not(.focus-mode) .controls .icon-btn:hover,
body.theme-dark.tree-viewer-page:not(.focus-mode) #backBtn:hover,
body.theme-dark.dashboard-page:not(.focus-mode) #backBtn:hover,
body.theme-dark.editor-page:not(.focus-mode) #backBtn:hover,
body.theme-dark.auth-page:not(.focus-mode) #backBtn:hover,
body.theme-dark.contact-page-layout:not(.focus-mode) #backBtn:hover {
  background: rgba(11, 29, 51, 0.92);
  color: #ffffff;
}

body.theme-dark.tree-viewer-page:not(.focus-mode) .brand-group #themeBtn,
body.theme-dark.dashboard-page:not(.focus-mode) .brand-group #themeBtn,
body.theme-dark.editor-page:not(.focus-mode) .brand-group #themeBtn,
body.theme-dark.auth-page:not(.focus-mode) .brand-group #themeBtn,
body.theme-dark.contact-page-layout:not(.focus-mode) .brand-group #themeBtn {
  background: rgba(11, 29, 51, 0.92);
}

body.theme-dark.tree-viewer-page:not(.focus-mode) .controls .icon-btn,
body.theme-dark.dashboard-page:not(.focus-mode) .controls .icon-btn,
body.theme-dark.editor-page:not(.focus-mode) .controls .icon-btn,
body.theme-dark.auth-page:not(.focus-mode) .controls .icon-btn,
body.theme-dark.contact-page-layout:not(.focus-mode) .controls .icon-btn,
body.theme-dark.tree-viewer-page:not(.focus-mode) #backBtn,
body.theme-dark.dashboard-page:not(.focus-mode) #backBtn,
body.theme-dark.editor-page:not(.focus-mode) #backBtn,
body.theme-dark.auth-page:not(.focus-mode) #backBtn,
body.theme-dark.contact-page-layout:not(.focus-mode) #backBtn {
  border-color: rgba(230, 238, 249, 0.18);
  background: rgba(11, 29, 51, 0.92);
  color: #ffffff;
}

body.tree-viewer-page:not(.focus-mode) .brand,
body.dashboard-page:not(.focus-mode) .brand,
body.editor-page:not(.focus-mode) .brand,
body.auth-page:not(.focus-mode) .brand,
body.contact-page-layout:not(.focus-mode) .brand {
  display: none;
}

body.tree-viewer-page:not(.focus-mode) .controls,
body.dashboard-page:not(.focus-mode) .controls,
body.editor-page:not(.focus-mode) .controls,
body.auth-page:not(.focus-mode) .controls,
body.contact-page-layout:not(.focus-mode) .controls {
  position: fixed;
  top: var(--corner-controls-top);
  right: var(--corner-controls-inset);
  left: auto;
  bottom: auto;
  transform: none;
  z-index: 8;
  flex: 0 1 auto;
  width: auto;
  max-width: min(80vw, 1080px);
  margin-left: 0;
  padding: 0;
  display: flex;
  align-items: center;
  justify-content: flex-end;
  gap: 8px;
  flex-wrap: nowrap;
  overflow-x: auto;
  overflow-y: visible;
  scrollbar-width: none;
  pointer-events: auto;
}

/* Neutralize legacy mobile header transforms for simple/dashboard control groups. */
body.auth-page:not(.focus-mode) .controls-simple,
body.contact-page-layout:not(.focus-mode) .controls-simple,
body.dashboard-page:not(.focus-mode) .controls-dashboard {
  position: fixed;
  top: var(--corner-controls-top);
  right: var(--corner-controls-inset);
  left: auto;
  bottom: auto;
  transform: none;
}

body.tree-viewer-page:not(.focus-mode) .controls::-webkit-scrollbar,
body.dashboard-page:not(.focus-mode) .controls::-webkit-scrollbar,
body.editor-page:not(.focus-mode) .controls::-webkit-scrollbar,
body.auth-page:not(.focus-mode) .controls::-webkit-scrollbar,
body.contact-page-layout:not(.focus-mode) .controls::-webkit-scrollbar {
  display: none;
}

body.tree-viewer-page:not(.focus-mode) .controls > button,
body.dashboard-page:not(.focus-mode) .controls > button,
body.editor-page:not(.focus-mode) .controls > button,
body.auth-page:not(.focus-mode) .controls > button,
body.contact-page-layout:not(.focus-mode) .controls > button,
body.tree-viewer-page:not(.focus-mode) .controls > a,
body.dashboard-page:not(.focus-mode) .controls > a,
body.editor-page:not(.focus-mode) .controls > a,
body.auth-page:not(.focus-mode) .controls > a,
body.contact-page-layout:not(.focus-mode) .controls > a,
body.tree-viewer-page:not(.focus-mode) .controls > a > button,
body.dashboard-page:not(.focus-mode) .controls > a > button,
body.editor-page:not(.focus-mode) .controls > a > button,
body.auth-page:not(.focus-mode) .controls > a > button,
body.contact-page-layout:not(.focus-mode) .controls > a > button,
body.tree-viewer-page:not(.focus-mode) .controls .icon-btn,
body.dashboard-page:not(.focus-mode) .controls .icon-btn,
body.editor-page:not(.focus-mode) .controls .icon-btn,
body.auth-page:not(.focus-mode) .controls .icon-btn,
body.contact-page-layout:not(.focus-mode) .controls .icon-btn,
body.tree-viewer-page:not(.focus-mode) #upcomingBtn,
body.dashboard-page:not(.focus-mode) #upcomingBtn,
body.editor-page:not(.focus-mode) #upcomingBtn,
body.auth-page:not(.focus-mode) #upcomingBtn,
body.contact-page-layout:not(.focus-mode) #upcomingBtn {
  min-height: var(--corner-control-size);
  border-radius: var(--radius-control);
}

body.tree-viewer-page:not(.focus-mode) .controls .icon-btn,
body.dashboard-page:not(.focus-mode) .controls .icon-btn,
body.editor-page:not(.focus-mode) .controls .icon-btn,
body.auth-page:not(.focus-mode) .controls .icon-btn,
body.contact-page-layout:not(.focus-mode) .controls .icon-btn,
body.tree-viewer-page:not(.focus-mode) #backBtn,
body.dashboard-page:not(.focus-mode) #backBtn,
body.editor-page:not(.focus-mode) #backBtn,
body.auth-page:not(.focus-mode) #backBtn,
body.contact-page-layout:not(.focus-mode) #backBtn {
  width: var(--corner-control-size);
  height: var(--corner-control-size);
  min-width: var(--corner-control-size);
  padding: 0;
  margin: 0;
  justify-content: center;
}

body.tree-viewer-page:not(.focus-mode) .controls-tree,
body.editor-page:not(.focus-mode) .controls-editor {
  max-width: min(80vw, 1160px);
}

@media (max-width: 768px) {
  body.tree-viewer-page:not(.focus-mode),
  body.dashboard-page:not(.focus-mode),
  body.editor-page:not(.focus-mode),
  body.auth-page:not(.focus-mode),
  body.contact-page-layout:not(.focus-mode) {
    --corner-controls-top: calc(env(safe-area-inset-top) + 12px);
    --corner-controls-inset: 12px;
    --corner-control-size: 44px;
    --floating-header-space: calc(var(--corner-controls-top) + var(--corner-control-size) + 8px);
  }

  body.tree-viewer-page:not(.focus-mode) .topbar,
  body.dashboard-page:not(.focus-mode) .topbar,
  body.editor-page:not(.focus-mode) .topbar,
  body.auth-page:not(.focus-mode) .topbar,
  body.contact-page-layout:not(.focus-mode) .topbar {
    height: var(--floating-header-space);
    min-height: var(--floating-header-space);
  }

  body.tree-viewer-page:not(.focus-mode) .controls,
  body.dashboard-page:not(.focus-mode) .controls,
  body.editor-page:not(.focus-mode) .controls,
  body.auth-page:not(.focus-mode) .controls,
  body.contact-page-layout:not(.focus-mode) .controls {
    gap: 6px;
    max-width: min(74vw, 560px);
  }

  body.tree-viewer-page:not(.focus-mode) .controls > button,
  body.dashboard-page:not(.focus-mode) .controls > button,
  body.editor-page:not(.focus-mode) .controls > button,
  body.auth-page:not(.focus-mode) .controls > button,
  body.contact-page-layout:not(.focus-mode) .controls > button,
  body.tree-viewer-page:not(.focus-mode) .controls > a,
  body.dashboard-page:not(.focus-mode) .controls > a,
  body.editor-page:not(.focus-mode) .controls > a,
  body.auth-page:not(.focus-mode) .controls > a,
  body.contact-page-layout:not(.focus-mode) .controls > a,
  body.tree-viewer-page:not(.focus-mode) .controls > a > button,
  body.dashboard-page:not(.focus-mode) .controls > a > button,
  body.editor-page:not(.focus-mode) .controls > a > button,
  body.auth-page:not(.focus-mode) .controls > a > button,
  body.contact-page-layout:not(.focus-mode) .controls > a > button,
  body.tree-viewer-page:not(.focus-mode) .controls .icon-btn,
  body.dashboard-page:not(.focus-mode) .controls .icon-btn,
  body.editor-page:not(.focus-mode) .controls .icon-btn,
  body.auth-page:not(.focus-mode) .controls .icon-btn,
  body.contact-page-layout:not(.focus-mode) .controls .icon-btn,
  body.tree-viewer-page:not(.focus-mode) #upcomingBtn,
  body.dashboard-page:not(.focus-mode) #upcomingBtn,
  body.editor-page:not(.focus-mode) #upcomingBtn,
  body.auth-page:not(.focus-mode) #upcomingBtn,
  body.contact-page-layout:not(.focus-mode) #upcomingBtn {
    min-height: 44px;
    border-radius: var(--radius-control);
    padding: 0 10px;
  }

  body.tree-viewer-page:not(.focus-mode) .controls .icon-btn,
  body.dashboard-page:not(.focus-mode) .controls .icon-btn,
  body.editor-page:not(.focus-mode) .controls .icon-btn,
  body.auth-page:not(.focus-mode) .controls .icon-btn,
  body.contact-page-layout:not(.focus-mode) .controls .icon-btn,
  body.tree-viewer-page:not(.focus-mode) #backBtn,
  body.dashboard-page:not(.focus-mode) #backBtn,
  body.editor-page:not(.focus-mode) #backBtn,
  body.auth-page:not(.focus-mode) #backBtn,
  body.contact-page-layout:not(.focus-mode) #backBtn {
    width: 44px;
    height: 44px;
    min-width: 44px;
    padding: 0;
  }

  body.tree-viewer-page:not(.focus-mode) .controls-tree,
  body.editor-page:not(.focus-mode) .controls-editor {
    max-width: min(74vw, 620px);
  }
}

@media (max-width: 640px) {
  body.tree-viewer-page:not(.focus-mode),
  body.dashboard-page:not(.focus-mode),
  body.editor-page:not(.focus-mode),
  body.auth-page:not(.focus-mode),
  body.contact-page-layout:not(.focus-mode) {
    --corner-controls-inset: 8px;
  }
}

/* Keep header control hover/pulse effects fully visible (no clipping). */
body.tree-viewer-page:not(.focus-mode) .topbar,
body.dashboard-page:not(.focus-mode) .topbar,
body.editor-page:not(.focus-mode) .topbar,
body.auth-page:not(.focus-mode) .topbar,
body.contact-page-layout:not(.focus-mode) .topbar {
  overflow: visible;
  padding: 0;
}

body.tree-viewer-page:not(.focus-mode) .controls,
body.dashboard-page:not(.focus-mode) .controls,
body.editor-page:not(.focus-mode) .controls,
body.auth-page:not(.focus-mode) .controls,
body.contact-page-layout:not(.focus-mode) .controls,
body.tree-viewer-page:not(.focus-mode) .controls-tree,
body.editor-page:not(.focus-mode) .controls-editor {
  overflow-y: visible;
  padding-top: 0;
  padding-bottom: 0;
}

/* Universal header controls: identical structure/position/appearance across all pages. */
:root {
  --header-corner-top: 24px;
  --header-corner-inset: 24px;
  --header-corner-size: 48px;
  --header-corner-gap: 8px;
}

@media (max-width: 768px) {
  :root {
    --header-corner-top: calc(env(safe-area-inset-top) + 12px);
    --header-corner-inset: 12px;
    --header-corner-size: 44px;
  }
}

@media (max-width: 640px) {
  :root {
    --header-corner-inset: 8px;
  }
}

body:not(.focus-mode) .app-header {
  position: relative;
  height: calc(var(--header-corner-top) + var(--header-corner-size) + 8px);
  min-height: calc(var(--header-corner-top) + var(--header-corner-size) + 8px);
  margin: 0;
  padding: 0;
  border: 0;
  background: transparent;
  box-shadow: none;
  backdrop-filter: none;
  overflow: visible;
  pointer-events: none;
  z-index: 20;
}

body:not(.focus-mode) .app-header .brand-group {
  position: fixed;
  top: var(--header-corner-top);
  left: var(--header-corner-inset);
  z-index: 21;
  width: auto;
  min-width: var(--header-corner-size);
  margin: 0;
  padding: 0;
  display: flex;
  align-items: center;
  justify-content: flex-start;
  pointer-events: auto;
}

body:not(.focus-mode) .app-header .brand {
  display: none;
}

body:not(.focus-mode) .app-header .controls {
  position: fixed;
  top: var(--header-corner-top);
  right: var(--header-corner-inset);
  left: auto;
  bottom: auto;
  transform: none;
  z-index: 21;
  width: auto;
  max-width: min(80vw, 1080px);
  margin: 0;
  padding: 0;
  display: flex;
  align-items: center;
  justify-content: flex-end;
  gap: var(--header-corner-gap);
  flex-wrap: nowrap;
  overflow-x: auto;
  overflow-y: visible;
  pointer-events: auto;
  scrollbar-width: none;
}

body:not(.focus-mode) .app-header .controls::-webkit-scrollbar {
  display: none;
}

body:not(.focus-mode) .app-header .controls > * {
  flex: 0 0 auto;
}

body:not(.focus-mode) .app-header .brand-group #themeBtn,
body:not(.focus-mode) .app-header .controls .icon-btn,
body:not(.focus-mode) .app-header #backBtn {
  appearance: none;
  border: 1px solid rgba(0, 0, 0, 0.08);
  background: #ffffff;
  color: #1f2937;
  width: var(--header-corner-size);
  height: var(--header-corner-size);
  min-width: var(--header-corner-size);
  min-height: var(--header-corner-size);
  padding: 0;
  border-radius: var(--radius-control);
  box-shadow: 0 2px 6px rgba(15, 23, 42, 0.08);
  display: inline-flex;
  align-items: center;
  justify-content: center;
  text-decoration: none;
  line-height: 1;
  cursor: pointer;
  position: relative;
  overflow: hidden;
  isolation: isolate;
  transition: transform var(--transition-base) ease, box-shadow var(--transition-base) ease, border-color var(--transition-base) ease, background var(--transition-base) ease, color var(--transition-base) ease;
}

body:not(.focus-mode) .app-header .brand-group #themeBtn::before,
body:not(.focus-mode) .app-header .controls .icon-btn::before,
body:not(.focus-mode) .app-header #backBtn::before {
  content: "";
  position: absolute;
  inset: 0;
  background: var(--gradient-primary);
  opacity: 0;
  transition: opacity var(--transition-base) ease;
  pointer-events: none;
  z-index: 0;
}

body:not(.focus-mode) .app-header .brand-group #themeBtn > *,
body:not(.focus-mode) .app-header .controls .icon-btn > *,
body:not(.focus-mode) .app-header #backBtn > * {
  position: relative;
  z-index: 1;
}

body:not(.focus-mode) .app-header .brand-group #themeBtn:hover::before,
body:not(.focus-mode) .app-header .controls .icon-btn:hover::before,
body:not(.focus-mode) .app-header #backBtn:hover::before {
  opacity: 0.08;
}

body:not(.focus-mode) .app-header .brand-group #themeBtn:hover,
body:not(.focus-mode) .app-header .controls .icon-btn:hover,
body:not(.focus-mode) .app-header #backBtn:hover {
  transform: translateY(-1px);
  box-shadow: 0 12px 24px rgba(15, 23, 42, 0.12);
  border-color: #3b82f6;
}

body:not(.focus-mode) .app-header .brand-group #themeBtn:active,
body:not(.focus-mode) .app-header .controls .icon-btn:active,
body:not(.focus-mode) .app-header #backBtn:active {
  transform: translateY(0);
}

body:not(.focus-mode) .app-header .brand-group #themeBtn:focus-visible,
body:not(.focus-mode) .app-header .controls .icon-btn:focus-visible,
body:not(.focus-mode) .app-header #backBtn:focus-visible {
  outline: 2px solid var(--ring);
  outline-offset: 2px;
}

body:not(.focus-mode) .app-header .brand-group #themeBtn .material-symbols-outlined,
body:not(.focus-mode) .app-header .controls .icon-btn .material-symbols-outlined,
body:not(.focus-mode) .app-header #backBtn .material-symbols-outlined {
  font-size: 22px;
  line-height: 1;
}

body:not(.focus-mode) .app-header .controls .icon-btn svg {
  width: 24px;
  height: 24px;
  display: block;
}

body:not(.focus-mode) .app-header .brand-group #themeBtn.sun-icon {
  color: #f59e0b;
}

body:not(.focus-mode) .app-header .brand-group #themeBtn.moon-icon {
  color: #60a5fa;
}

body.theme-dark:not(.focus-mode) .app-header .brand-group #themeBtn,
body.theme-dark:not(.focus-mode) .app-header .controls .icon-btn,
body.theme-dark:not(.focus-mode) .app-header #backBtn {
  border-color: rgba(230, 238, 249, 0.18);
  background: rgba(11, 29, 51, 0.92);
  color: #ffffff;
}

body.theme-dark:not(.focus-mode) .app-header .brand-group #themeBtn.sun-icon,
body.theme-dark:not(.focus-mode) .app-header .brand-group #themeBtn.moon-icon {
  filter: saturate(1.05);
}

/* Final header consistency overrides (do not redesign beyond controls). */
body.landing-page:not(.focus-mode) .app-header {
  height: 0;
  min-height: 0;
}

body:not(.focus-mode) .app-header .brand-group #themeBtn,
body:not(.focus-mode) .app-header .controls .icon-btn,
body:not(.focus-mode) .app-header #backBtn {
  background: #ffffff;
  border-color: rgba(0, 0, 0, 0.08);
  color: #1f2937;
}

body.theme-dark:not(.focus-mode) .app-header .brand-group #themeBtn,
body.theme-dark:not(.focus-mode) .app-header .controls .icon-btn,
body.theme-dark:not(.focus-mode) .app-header #backBtn {
  background: rgba(11, 29, 51, 0.92);
  border-color: rgba(230, 238, 249, 0.18);
  color: #ffffff;
}

body:not(.focus-mode) .app-header .controls.controls-simple,
body:not(.focus-mode) .app-header .controls.controls-dashboard {
  overflow: visible;
}

body:not(.focus-mode) .app-header .controls .icon-btn:hover,
body:not(.focus-mode) .app-header #backBtn:hover {
  transform: translateY(0);
}

/* Project-wide preference: no upward hover movement on buttons. */
button:hover,
input[type="button"]:hover,
input[type="submit"]:hover,
input[type="reset"]:hover,
.icon-btn:hover,
[class*="btn-"]:hover,
[class$="-btn"]:hover,
.dashboard-fab:hover,
.form-button:hover,
.google-button:hover,
.github-link:hover,
.coffee-btn:hover,
.triangle-btn:hover {
  transform: none !important;
}

@media (max-width: 768px) {
  body.tree-viewer-page:not(.focus-mode) .app-header .controls.controls-tree {
    left: calc(var(--header-corner-inset) + var(--header-corner-size) + 8px);
    right: var(--header-corner-inset);
    width: auto;
    max-width: none;
    flex-wrap: nowrap;
    justify-content: flex-start;
    gap: 6px;
    overflow-x: visible;
    overflow-y: visible;
  }

  body.tree-viewer-page:not(.focus-mode) .app-header {
    height: calc(var(--header-corner-top) + var(--header-corner-size) + 56px);
    min-height: calc(var(--header-corner-top) + var(--header-corner-size) + 56px);
  }

  body.tree-viewer-page:not(.focus-mode) .app-header .controls.controls-tree > button {
    flex: 0 0 auto;
    height: 48px;
    min-height: 48px;
    padding: 0 10px;
    font-size: 0.86rem;
    line-height: 1;
    white-space: nowrap;
  }

  body.tree-viewer-page:not(.focus-mode) .app-header .controls.controls-tree #dnaBtn,
  body.tree-viewer-page:not(.focus-mode) .app-header .controls.controls-tree #focusBtn {
    flex: 1 1 0;
    min-width: 76px;
    justify-content: center;
  }

  body.tree-viewer-page:not(.focus-mode) .app-header .controls.controls-tree #searchBtn,
  body.tree-viewer-page:not(.focus-mode) .app-header .controls.controls-tree #helpBtn,
  body.tree-viewer-page:not(.focus-mode) .app-header .controls.controls-tree #backBtn {
    flex: 0 0 44px;
    width: 44px;
    min-width: 44px;
    padding: 0;
    justify-content: center;
  }

  body.tree-viewer-page:not(.focus-mode) .app-header .controls.controls-tree #searchBtn .material-symbols-outlined,
  body.tree-viewer-page:not(.focus-mode) .app-header .controls.controls-tree #helpBtn .material-symbols-outlined {
    font-size: 18px;
  }

  body.tree-viewer-page:not(.focus-mode) .app-header .controls.controls-tree #backBtn .material-symbols-outlined {
    font-size: 20px;
  }

  body.tree-viewer-page:not(.focus-mode) .app-header .controls.controls-tree #upcomingContainer {
    position: fixed;
    top: calc(var(--header-corner-top) + var(--header-corner-size) + 8px);
    left: var(--header-corner-inset);
    right: var(--header-corner-inset);
    z-index: 21;
    order: 1;
    flex: 0 0 auto;
    min-width: 0;
    width: auto;
    margin: 0;
    display: flex;
    justify-content: flex-start;
  }

  body.tree-viewer-page:not(.focus-mode) .app-header .controls.controls-tree #upcomingBtn {
    width: 100%;
    max-width: 100%;
    justify-content: center;
    padding-inline: 10px;
  }

  body.tree-viewer-page:not(.focus-mode) .app-header .controls.controls-tree #upcomingName {
    min-width: 0;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
  }
}

@media (max-width: 640px) {
  body.tree-viewer-page:not(.focus-mode) .app-header {
    height: calc(var(--header-corner-top) + var(--header-corner-size) + 52px);
    min-height: calc(var(--header-corner-top) + var(--header-corner-size) + 52px);
  }

  body.tree-viewer-page:not(.focus-mode) .app-header .controls.controls-tree > button {
    height: 46px;
    min-height: 46px;
    font-size: 0.82rem;
  }

  body.tree-viewer-page:not(.focus-mode) .app-header .controls.controls-tree #dnaBtn,
  body.tree-viewer-page:not(.focus-mode) .app-header .controls.controls-tree #focusBtn {
    min-width: 72px;
    padding: 0 8px;
  }

  body.tree-viewer-page:not(.focus-mode) .app-header .controls.controls-tree #searchBtn,
  body.tree-viewer-page:not(.focus-mode) .app-header .controls.controls-tree #helpBtn,
  body.tree-viewer-page:not(.focus-mode) .app-header .controls.controls-tree #backBtn {
    flex-basis: 42px;
    width: 42px;
    min-width: 42px;
  }

  body.tree-viewer-page:not(.focus-mode) .app-header .controls.controls-tree #upcomingBtn {
    font-size: 0.82rem;
    padding-inline: 8px;
  }
}

@media (max-width: 768px) {
  body.tree-viewer-page.view-calendar:not(.focus-mode) .app-header {
    height: calc(var(--header-corner-top) + var(--header-corner-size) + 56px);
    min-height: calc(var(--header-corner-top) + var(--header-corner-size) + 56px);
  }

  body.tree-viewer-page.view-globe:not(.focus-mode) .app-header {
    height: calc(var(--header-corner-top) + var(--header-corner-size) + 8px);
    min-height: calc(var(--header-corner-top) + var(--header-corner-size) + 8px);
  }

  body.tree-viewer-page.view-calendar:not(.focus-mode) .app-header .controls.controls-tree,
  body.tree-viewer-page.view-globe:not(.focus-mode) .app-header .controls.controls-tree {
    left: auto;
    right: var(--header-corner-inset);
    width: auto;
    max-width: min(76vw, 460px);
    justify-content: flex-end;
    gap: 8px;
    overflow-x: visible;
  }

  body.tree-viewer-page.view-calendar:not(.focus-mode) #birthdaySection {
    inset: calc(var(--header-corner-top) + var(--header-corner-size) + 64px) 0 0 0;
  }

  body.tree-viewer-page.view-calendar:not(.focus-mode) .app-header .controls.controls-tree #upcomingContainer {
    position: fixed;
    top: calc(var(--header-corner-top) + var(--header-corner-size) + 8px);
    left: var(--header-corner-inset);
    right: var(--header-corner-inset);
    z-index: 21;
    display: flex;
    justify-content: flex-start;
    margin: 0;
    min-width: 0;
    width: auto;
  }

  body.tree-viewer-page.view-calendar:not(.focus-mode) .app-header .controls.controls-tree #upcomingBtn {
    width: 100%;
    max-width: 100%;
    justify-content: center;
    padding-inline: 10px;
  }

  body.tree-viewer-page.view-calendar:not(.focus-mode) .app-header .controls.controls-tree #upcomingName {
    min-width: 0;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
  }

  body.tree-viewer-page.view-globe:not(.focus-mode) .app-header .controls.controls-tree #upcomingContainer {
    display: none !important;
  }

  body.tree-viewer-page.view-calendar:not(.focus-mode) .app-header .controls.controls-tree > button,
  body.tree-viewer-page.view-globe:not(.focus-mode) .app-header .controls.controls-tree > button {
    flex: 0 0 44px;
    width: 44px;
    min-width: 44px;
    height: 44px;
    min-height: 44px;
    padding: 0;
    justify-content: center;
  }

  body.tree-viewer-page.view-calendar:not(.focus-mode) .app-header .controls.controls-tree #searchBtn .material-symbols-outlined,
  body.tree-viewer-page.view-calendar:not(.focus-mode) .app-header .controls.controls-tree #helpBtn .material-symbols-outlined,
  body.tree-viewer-page.view-globe:not(.focus-mode) .app-header .controls.controls-tree #searchBtn .material-symbols-outlined,
  body.tree-viewer-page.view-globe:not(.focus-mode) .app-header .controls.controls-tree #helpBtn .material-symbols-outlined,
  body.tree-viewer-page.view-calendar:not(.focus-mode) .app-header .controls.controls-tree #backBtn .material-symbols-outlined,
  body.tree-viewer-page.view-globe:not(.focus-mode) .app-header .controls.controls-tree #backBtn .material-symbols-outlined {
    font-size: 20px;
  }

  body.tree-viewer-page.view-globe:not(.focus-mode) .app-header .controls.controls-tree #zoomInBtn,
  body.tree-viewer-page.view-globe:not(.focus-mode) .app-header .controls.controls-tree #zoomOutBtn {
    font-size: 1.1rem;
    font-weight: 700;
    line-height: 1;
  }
}

@media (max-width: 640px) {
  body.tree-viewer-page.view-calendar:not(.focus-mode) .app-header {
    height: calc(var(--header-corner-top) + var(--header-corner-size) + 52px);
    min-height: calc(var(--header-corner-top) + var(--header-corner-size) + 52px);
  }

  body.tree-viewer-page.view-calendar:not(.focus-mode) #birthdaySection {
    inset: calc(var(--header-corner-top) + var(--header-corner-size) + 60px) 0 0 0;
  }

  body.tree-viewer-page.view-calendar:not(.focus-mode) .app-header .controls.controls-tree > button,
  body.tree-viewer-page.view-globe:not(.focus-mode) .app-header .controls.controls-tree > button {
    flex-basis: 42px;
    width: 42px;
    min-width: 42px;
    height: 42px;
    min-height: 42px;
  }

  body.tree-viewer-page.view-calendar:not(.focus-mode) .app-header .controls.controls-tree #upcomingBtn {
    font-size: 0.82rem;
    padding-inline: 8px;
  }
}