/* =========================================================
   Buried Keep — core_header.css
   Shared header chrome (hamburger container, title, sign-in, avatar button)
   Load order: global-1.css -> core_header.css -> core_menu.css -> core_<page>.css -> plugins
   ========================================================= */

:root{
  --bk-header-height: 70px;
}

/* Header shell */
.bk-header{
  height: 10%;
  min-height: var(--bk-header-height);
  background: var(--bg-panel);
  border-bottom: var(--border-soft);
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 1rem;
  position: relative;
  z-index: 10;
}

/* Center title */
.bk-site-title{
  font-family: var(--font-display);
  font-size: 2rem;
  letter-spacing: 1px;
  margin: 0;
  text-align: center;
  flex: 1;
  color: var(--text-main);
}

/* Sign-in / sign-out button (shared visual) */
.bk-signin-btn{
  font-family: var(--font-display);
  border: var(--border-strong);
  background: var(--bg-panel-soft);
  padding: 0.5rem 1rem;
  border-radius: 10px;
  cursor: pointer;
  transition: transform 0.2s ease;
}

.bk-signin-btn:hover{
  transform: scale(1.03);
}

/* Right-side user cluster: avatar + sign button */
.bk-user-wrap{
  position: relative;
  display: flex;
  flex-direction: row;
  align-items: center;
  justify-content: flex-end;
  gap: 10px;
}

/* Avatar circle button */
.bk-avatar-btn{
  display: inline-flex;
  align-items: center;
  justify-content: center;

  width: 38px;
  height: 38px;

  border-radius: 999px;
  border: 1px solid rgba(0,0,0,0.28);
  background: rgba(255,255,255,0.18);
  cursor: pointer;
  padding: 0;
  user-select: none;
  position: relative;
  overflow: hidden;
}

.bk-avatar-btn:hover{
  background: rgba(255,255,255,0.28);
}

.bk-avatar-letter{
  font-weight: 900;
  font-size: 0.95rem;
  line-height: 1;
  opacity: 0.92;
}

.bk-avatar-btn.bk-hidden{
  display: none;
}

.bk-avatar-img{
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: none;
}