.railnav {
  --railnav-bg: var(--surface-neutral);
  --railnav-border: var(--border-subtle);
  --railnav-fg: var(--text-secondary);
  --railnav-fg-strong: var(--text-primary);
  --railnav-fg-muted: var(--text-tertiary);
  --railnav-hover: var(--surface-neutral);
  --railnav-selected: var(--border-subtle);
  --railnav-accent: var(--accent-primary);
  --railnav-overlay: var(--surface-base);
  --railnav-font: 'Sora', system-ui, -apple-system, sans-serif;

  font-family: var(--railnav-font);

  font-size: var(--railnav-item-font-size);
  line-height: var(--leading-normal);

  width: 100%;
  min-width: 0;
  max-width: 100%;
  height: 100%;
  background-color: var(--railnav-bg);
  display: flex;
  flex-direction: column;
  overflow: hidden;
}

.shell--rail-collapsed .railnav__item-label {
  opacity: 0;
  width: 0;
  flex: 0 0 0;
  overflow: hidden;
}

.shell--rail-collapsed .railnav__audience,
.shell--rail-collapsed .railnav__unread {
  display: none;
}

.shell--rail-collapsed .railnav__group {
  opacity: 0;
  height: 0;
  padding: 0;
  margin: 0;
  overflow: hidden;
}

.shell--rail-collapsed .railnav__list {
  overflow-x: hidden;
}

.shell--rail-collapsed .railnav__item {
  justify-content: center;
  gap: 0;
  padding-left: 0;
  padding-right: 0;
}

.railnav__list {
  flex: 1;
  min-width: 0;
  overflow-y: auto;
  overflow-x: hidden;

  padding: var(--space-4) var(--space-2) var(--space-2);
}

.railnav__section {
  margin-bottom: var(--space-4);
  min-width: 0;
  max-width: 100%;
}

.railnav__group {
  font-size: var(--railnav-group-font-size);
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--railnav-fg-muted);
  padding: var(--space-2) var(--space-3);
  font-weight: 600;
  min-width: 0;
  max-width: 100%;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
  transition: opacity var(--duration-fast), height var(--duration-fast);
}

.railnav__group-form {
  display: block;
  margin: 0;
  min-width: 0;
  max-width: 100%;
}

button.railnav__group--toggle {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-2);
  width: 100%;
  border: 0;
  background: transparent;
  cursor: pointer;
  text-align: left;
  font-family: inherit;
  font-size: var(--railnav-group-font-size);
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--railnav-fg-muted);
  padding: var(--space-2) var(--space-3);
  font-weight: 600;
  min-width: 0;
  max-width: 100%;
}

button.railnav__group--toggle:hover,
button.railnav__group--toggle:focus,
button.railnav__group--toggle:focus-visible,
button.railnav__group--toggle:active {
  color: var(--railnav-fg-muted);
  background: transparent;
  outline: none;
}

.railnav__group-label {
  min-width: 0;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.railnav__group-chevron {
  flex: none;
  font-size: var(--text-base);
  color: inherit;
}

.railnav__section--collapsed > .railnav__section-body {
  display: none;
}

.shell--rail-collapsed .railnav__group-form,
.shell--rail-collapsed button.railnav__group--toggle {
  opacity: 0;
  height: 0;
  padding: 0;
  margin: 0;
  overflow: hidden;
}

.railnav__divider {
  height: 1px;
  margin: var(--space-2) var(--space-3);
  background-color: var(--railnav-border);
  border: 0;
}

.shell--rail-collapsed .railnav__divider {
  margin-left: var(--space-2);
  margin-right: var(--space-2);
}

.shell--rail-collapsed .railnav__section > .railnav__switcher-unit {
  opacity: 0;
  height: 0;
  padding: 0;
  margin: 0;
  overflow: hidden;
}

.railnav__item {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  padding: var(--space-2) var(--space-3);
  border-radius: var(--radius-lg);
  color: var(--railnav-fg);
  font-size: inherit;
  text-decoration: none;
  min-width: 0;
  max-width: 100%;
  transition: all var(--duration-fast);
}

.railnav__item:hover {
  background-color: var(--railnav-hover);
  color: var(--railnav-fg-strong);
}

.railnav__item.active {
  background-color: var(--railnav-selected);
  color: var(--railnav-accent);
  font-weight: 600;
  box-shadow: inset 3px 0 0 var(--railnav-accent);
}

.railnav__item .material-symbols-rounded {
  font-size: var(--railnav-icon-size);
  flex-shrink: 0;
}

.railnav__item-label {
  flex: 1;
  min-width: 0;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
  transition: opacity var(--duration-fast), width var(--duration-fast);
}

.railnav__audience {
  flex-shrink: 0;
  margin-left: auto;
  padding: var(--space-0) var(--space-1);
  border: 1px solid var(--accent-primary);
  border-radius: var(--radius-sm);
  color: var(--accent-primary);
  font-size: var(--railnav-audience-font-size);
  font-weight: var(--weight-semibold);
  line-height: 1.2;
  white-space: nowrap;
}

.railnav__unread {
  margin-left: auto;
}

.railnav__item--disabled,
.railnav__item--disabled .material-symbols-rounded,
.railnav__item--disabled .railnav__item-label {
  color: var(--text-tertiary);
}

.railnav__item--disabled .railnav__audience {
  border-color: var(--border-subtle);
  color: var(--text-tertiary);
}

.railnav__item--disabled:hover,
.railnav__item--disabled.active {
  background-color: var(--surface-hover);
  color: var(--text-tertiary);
}

.railnav--hidden .railnav {
  display: none;
}

@media (max-width: 768px) {
  .railnav,
  .shell--rail-collapsed .railnav {
    transform: translateX(-100%);
    transition: transform var(--duration-normal) var(--ease-out);
    z-index: var(--z-modal);
    width: 280px;
    box-shadow: var(--shadow-xl);
  }

  .shell--rail-collapsed .railnav__item-label {
    opacity: 1;
    width: auto;
    flex: 1;
    min-width: 0;
    overflow: hidden;
    text-overflow: ellipsis;
  }
  .shell--rail-collapsed .railnav__group {
    opacity: 1;
    height: auto;
    padding: var(--space-2) var(--space-3);
    margin: 0;
    overflow: hidden;
    text-overflow: ellipsis;
  }
  .shell--rail-collapsed .railnav__group-form,
  .shell--rail-collapsed button.railnav__group--toggle {
    opacity: 1;
    height: auto;
    padding: 0;
    margin: 0;
    overflow: visible;
  }
  .shell--rail-collapsed button.railnav__group--toggle {
    padding: var(--space-2) var(--space-3);
  }
  .shell--rail-collapsed .railnav__head {
    justify-content: space-between;
  }
  .shell--rail-collapsed .railnav__item {
    justify-content: flex-start;
    gap: var(--space-3);
    padding-left: var(--space-3);
    padding-right: var(--space-3);
  }

  .shell::before {
    content: "";
    position: fixed;
    inset: 0;
    z-index: calc(var(--z-modal) - 1);
    background: rgba(0, 0, 0, 0.3);
    opacity: 0;
    pointer-events: none;
    transition: opacity var(--duration-normal) var(--ease-out);
  }

  .railnav--open .railnav,
  .railnav--open.shell--rail-collapsed .railnav {
    transform: translateX(0);
  }

  .railnav--open::before {
    opacity: 1;
    pointer-events: auto;
  }

  .railnav--open .shell__workspace {
    overflow: hidden;
  }
}

.railnav--readonly .railnav__list .railnav__item {
  color: var(--text-disabled);
  pointer-events: none;
}

.railnav--readonly .railnav__list .railnav__item:hover {
  background-color: transparent;
}

.railnav--readonly .railnav__list .railnav__item .material-symbols-rounded {
  color: var(--text-disabled);
}

.railnav--readonly .railnav__switcher {
  pointer-events: none;
  cursor: default;
}

.railnav--readonly .railnav__switcher > .material-symbols-rounded {
  display: none;
}

.railnav__session {
  flex-shrink: 0;
  padding: 0 var(--space-2);
}

.railnav__session .railnav__section {
  margin-bottom: var(--space-4);
}

.railnav__anchor {
  margin-top: auto;
  flex-shrink: 0;
  position: relative;
  padding: var(--space-2);
  border-top: 1px solid var(--railnav-border);
}
.railnav__anchor-bar {
  display: flex;
  align-items: center;
  gap: var(--space-1);
}

button.railnav__collapse-btn {
  width: 100%;
  border: none;
  background: transparent;
  cursor: pointer;
  font: inherit;
  text-align: left;
}

.railnav__actor-mark {
  width: var(--railnav-mark-size);
  height: var(--railnav-mark-size);
  flex-shrink: 0;
  border-radius: var(--radius-md);
  display: inline-flex;
  align-items: center;
  justify-content: center;
  overflow: hidden;
  background: var(--railnav-accent);
  color: var(--text-on-accent);
  font-family: var(--font-display);
  font-weight: 800;
  font-size: var(--railnav-mark-font-size);
  letter-spacing: -0.02em;
}
.railnav__actor-mark img { width: 100%; height: 100%; object-fit: cover; }

.railnav__actor-mark[data-theme] { background: var(--accent-primary); }

.railnav__switcher-unit {
  position: relative;
  flex: 1;
  min-width: 0;
}
.railnav__switcher {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  flex: 1;
  min-width: 0;
  width: 100%;
  padding: var(--space-1) var(--space-2);
  border: none;

  background: var(--accent-subtle);
  box-shadow: none;
  cursor: pointer;
  border-radius: var(--radius-md);
  text-align: left;
  color: var(--railnav-fg-strong);
  font-weight: 600;
  transition: background var(--duration-fast) var(--ease-out);
}
.railnav__switcher:hover { background: var(--accent-muted); }
.railnav__switcher-name {
  flex: 1;
  min-width: 0;
  font-weight: inherit;

  font-size: var(--railnav-item-font-size);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}
.railnav__switcher > .material-symbols-rounded {
  color: var(--text-tertiary);
  font-size: var(--railnav-chevron-size);
  flex-shrink: 0;
}

.railnav__switcher-menu {
  position: absolute;
  left: var(--space-2);
  right: var(--space-2);
  top: calc(100% - var(--space-1));
  bottom: auto;
  display: flex;
  flex-direction: column;
  gap: var(--space-0-5);
  padding: var(--space-1);
  background: var(--railnav-overlay);
  border: 1px solid var(--railnav-border);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-lg);
  z-index: var(--z-dropdown);
}
.railnav__anchor .railnav__switcher-menu {
  top: auto;
  bottom: calc(100% - var(--space-1));
}

.railnav__switcher-unit:has([aria-expanded="true"]) {
  z-index: var(--z-dropdown);
}
.railnav__switcher-menu[hidden] { display: none; }

.railnav__switcher-opt-form {
  display: flex;
  flex-direction: column;
  width: 100%;
  margin: 0;
}

.railnav__switcher-opt {
  display: flex;
  align-items: center;
  justify-content: flex-start;
  gap: var(--space-2);
  width: 100%;
  padding: var(--space-2);
  border: none;
  border-radius: var(--radius-md);
  background: transparent;
  cursor: pointer;
  text-align: left;
  text-decoration: none;
  color: var(--railnav-fg);
  font: inherit;
  font-size: var(--railnav-item-font-size);
  transition: background var(--duration-fast);
}
.railnav__switcher-opt:hover { background: var(--railnav-hover); }
.railnav__switcher-opt--active { font-weight: 600; }
.railnav__switcher-opt--active .material-symbols-rounded {
  color: var(--railnav-accent);
  margin-left: auto;
  font-size: var(--railnav-chevron-size);
}
.railnav__switcher-opt-name {
  flex: 1;
  min-width: 0;
  text-align: left;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.shell--rail-collapsed .railnav__anchor { padding: var(--space-2) 0; }
.shell--rail-collapsed .railnav__anchor-bar { flex-direction: column; gap: var(--space-1); }
.shell--rail-collapsed .railnav__switcher {
  flex: none;
  justify-content: center;
  padding: var(--space-2);
}
.shell--rail-collapsed .railnav__switcher-name,
.shell--rail-collapsed .railnav__switcher > .material-symbols-rounded { display: none; }
.shell--rail-collapsed .railnav__switcher-menu {
  left: calc(100% + var(--space-2));
  right: auto;
  top: auto;
  bottom: 0;
  width: var(--railnav-switcher-menu-width);
}

.railnav__collapse-icon--open { display: none; }
.shell--rail-collapsed .railnav__collapse-icon--close { display: none; }
.shell--rail-collapsed .railnav__collapse-icon--open { display: inline-flex; }

.shell__rail-overlay .railnav__collapse-btn { display: none; }