/* ── App Shell ─────────────────────────────────────────────────────────────── */
.page-app {
  display: flex;
  height: 100vh;
  overflow: hidden;
}

/* ── Sidebar ───────────────────────────────────────────────────────────────── */
.sidebar {
  width: var(--sidebar-w);
  flex-shrink: 0;
  background: var(--sidebar-bg);
  border-right: 1px solid var(--border);
  display: flex;
  flex-direction: column;
  padding: 24px 16px;
  gap: 8px;
  backdrop-filter: blur(22px);
  box-shadow: inset -1px 0 0 rgba(255,255,255,.04);
  overflow: hidden;
  position: relative;
  height: 100vh;
  /* 展开时：先拉开宽度 (0.35s)，再淡入内容 (0.2s, 延迟 0.18s) */
  transition: width .35s cubic-bezier(0.16, 1, 0.3, 1),
              padding .35s cubic-bezier(0.16, 1, 0.3, 1),
              border .35s cubic-bezier(0.16, 1, 0.3, 1),
              opacity .2s ease-out .18s;
}

/* Sidebar logo stays fixed at top */
.sidebar-logo { flex-shrink: 0; }

/* Sidebar nav scrolls when overflow */
.sidebar-nav {
  flex: 1;
  overflow-y: auto;
  overflow-x: hidden;
  padding-right: 4px;
  margin-right: -4px;
}

/* Upload button & footer pinned at bottom */
.btn-upload-sidebar,
.sidebar-footer { flex-shrink: 0; }

.sidebar.collapsed {
  width: 0;
  padding: 24px 0;
  border-right-color: transparent;
  opacity: 0;
  pointer-events: none;
  /* 收起时：先淡出内容 (0.18s)，再收缩宽度 (0.35s, 延迟 0.15s) */
  transition: opacity .18s ease-in,
              width .35s cubic-bezier(0.16, 1, 0.3, 1) .15s,
              padding .35s cubic-bezier(0.16, 1, 0.3, 1) .15s,
              border .35s cubic-bezier(0.16, 1, 0.3, 1) .15s;
}

/* ── Sidebar Collapse / Expand Buttons ─────────────────────────────────────── */
.btn-collapse-sidebar {
  position: absolute;
  top: 14px;
  right: 10px;
  width: 28px; height: 28px;
  background: rgba(232,232,240,.08);
  border: 1px solid var(--border);
  border-radius: 50%;
  color: var(--text-muted);
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  transition: all .2s;
  z-index: 2;
  flex-shrink: 0;
}
.btn-collapse-sidebar svg { width: 14px; height: 14px; }
.btn-collapse-sidebar:hover { background: rgba(245,213,98,.12); color: var(--accent); border-color: rgba(245,213,98,.3); }

.btn-expand-sidebar {
  position: absolute;
  top: 14px;
  left: 12px;
  width: 32px; height: 32px;
  background: rgba(14,18,44,.88);
  border: 1px solid var(--border);
  border-radius: 50%;
  color: var(--text-muted);
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  transition: all .2s;
  z-index: 10;
  box-shadow: 0 4px 14px rgba(0,0,0,.25);
}
.btn-expand-sidebar svg { width: 15px; height: 15px; }
.btn-expand-sidebar:hover { background: rgba(20,24,52,.95); color: var(--accent); box-shadow: 0 6px 18px rgba(0,0,0,.35); }
.btn-expand-sidebar.hidden { display: none; }

.sidebar-logo {
  padding: 4px 8px 20px;
  border-bottom: 1px solid var(--border);
  margin-bottom: 8px;
}

.sidebar-logo .brand-logo-text { font-size: 1.2rem; }

.sidebar-nav {
  display: flex;
  flex-direction: column;
  gap: 4px;
  flex: 1;
}

.nav-item {
  display: flex;
  align-items: center;
  gap: 10px;
  width: 100%;
  padding: 11px 14px;
  background: rgba(232,232,240,.03);
  border: 1px solid transparent;
  border-radius: 999px;
  color: var(--text-muted);
  font-size: .9rem;
  font-weight: 500;
  text-align: left;
  transition: transform .18s, box-shadow .22s, background .22s, color .22s;
}
.nav-item svg { width: 18px; height: 18px; flex-shrink: 0; }
.nav-item:hover { background: rgba(232,232,240,.06); color: var(--text); box-shadow: var(--button-shadow); }
.nav-item.active {
  background: rgba(245,213,98,.12);
  color: var(--accent);
  border: 1px solid rgba(245,213,98,.2);
  box-shadow: var(--button-shadow);
}

/* ── Nav Group Header ──────────────────────────────────────────────────── */
.nav-group-header {
  display: flex;
  align-items: center;
  gap: 10px;
  width: 100%;
  padding: 11px 14px;
  background: rgba(232,232,240,.03);
  border: 1px solid transparent;
  border-radius: 999px;
  color: var(--text-muted);
  font-size: .9rem;
  font-weight: 500;
  text-align: left;
  cursor: pointer;
  transition: transform .18s, box-shadow .22s, background .22s, color .22s;
}
.nav-group-header svg { width: 18px; height: 18px; flex-shrink: 0; }
.nav-group-header:hover { background: rgba(232,232,240,.06); color: var(--text); box-shadow: var(--button-shadow); }
.nav-group-header.expanded,
.nav-group-header.active {
  background: rgba(245,213,98,.12);
  color: var(--accent);
  border: 1px solid rgba(245,213,98,.2);
  box-shadow: var(--button-shadow);
}

.nav-group-arrow {
  margin-left: auto;
  font-size: .7rem;
  transition: transform .22s;
}
.nav-group-header.expanded .nav-group-arrow,
.nav-group-header.active .nav-group-arrow {
  transform: rotate(180deg);
}

/* ── Nav Group Items (sub-items) ───────────────────────────────────────── */
.nav-group-items {
  max-height: 0;
  overflow: hidden;
  display: flex;
  flex-direction: column;
  gap: 3px;
  padding-left: 22px;
  transition: max-height .35s cubic-bezier(0.16, 1, 0.3, 1);
}
.nav-group-items.expanded {
  max-height: 200px;
  transition: max-height .35s cubic-bezier(0.16, 1, 0.3, 1);
}

/* 收起时：max-height 等内容淡出后再缩（延迟 0.15s） */
.nav-group-items:not(.expanded) {
  transition: max-height .35s cubic-bezier(0.16, 1, 0.3, 1) .15s;
}

/* Inner wrapper：opacity + translateY 控制内容显隐 */
.nav-group-inner {
  display: flex;
  flex-direction: column;
  gap: 3px;
  opacity: 0;
  transform: translateY(-8px);
  pointer-events: none;
  transition: opacity .18s ease-in,
              transform .18s ease-in;
}
.nav-group-items.expanded .nav-group-inner {
  opacity: 1;
  transform: translateY(0);
  pointer-events: auto;
  transition: opacity .2s ease-out .18s,
              transform .2s cubic-bezier(0.16, 1, 0.3, 1) .18s;
}

.nav-sub-item {
  padding: 9px 14px;
  font-size: .84rem;
  border-radius: 999px;
}
.nav-sub-item svg { width: 16px; height: 16px; }

/* ensure group expands when any sub-item is active — JS adds .expanded */

.btn-upload-sidebar {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  width: 100%;
  padding: 11px;
  background: var(--accent);
  color: var(--button-text);
  border: none;
  border-radius: 999px;
  font-size: .88rem;
  font-weight: 600;
  transition: transform .18s, box-shadow .22s, background .22s, color .22s;
  box-shadow: 0 0 20px rgba(245,213,98,.25);
  margin-top: auto;
}
.btn-upload-sidebar svg { width: 16px; height: 16px; }
.btn-upload-sidebar:hover { background: #E0C550; box-shadow: 0 0 30px rgba(245,213,98,.4); }

.sidebar-footer {
  display: flex;
  align-items: center;
  gap: 8px;
  padding-top: 16px;
  border-top: 1px solid var(--border);
  margin-top: 8px;
}

.sidebar-user {
  display: flex;
  align-items: center;
  gap: 10px;
  flex: 1;
  min-width: 0;
  cursor: pointer;
}

.avatar {
  width: 32px; height: 32px;
  background: linear-gradient(135deg, #F5D562, #D4A030);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: .8rem;
  font-weight: 700;
  color: #0A0E27;
  flex-shrink: 0;
}

#sidebar-username {
  font-size: .85rem;
  color: var(--text-dim);
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.btn-logout {
  width: 32px; height: 32px;
  background: rgba(232,232,240,.05);
  border: 1px solid var(--border);
  border-radius: 999px;
  color: var(--text-muted);
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
  transition: transform .18s, box-shadow .22s, background .22s, color .22s;
}
.btn-logout svg { width: 15px; height: 15px; }
.btn-logout:hover { background: rgba(197,108,108,.15); border-color: rgba(197,108,108,.25); color: #d94d67; }

/* ── Content Area ──────────────────────────────────────────────────────────── */
.content {
  flex: 1;
  overflow-y: auto;
  background: rgba(0,0,0,.12);
  backdrop-filter: blur(3px);
  position: relative;
}

.content-view { padding: 36px 28px; }

.view-header { margin-bottom: 28px; display: flex; align-items: flex-start; justify-content: space-between; gap: 16px; flex-wrap: wrap; }
.view-header-right { display: flex; align-items: center; gap: 8px; }
.view-title { font-size: 1.5rem; font-weight: 700; color: var(--text); }
.view-sub { font-size: .85rem; color: var(--text-muted); margin-top: 4px; }

.search-input {
  padding: 8px 14px; background: rgba(232,232,240,.05); border: 1px solid var(--border);
  border-radius: 999px; color: var(--text); font-size: .85rem; outline: none;
  width: 190px; transition: border-color .2s;
}
.search-input::placeholder { color: var(--text-muted); }
.search-input:focus { border-color: var(--border-accent); }