:root {
  --accent: #6366f1;
  --accent-hover: #4f46e5;
  --accent-gradient: linear-gradient(135deg, #6366f1 0%, #8b5cf6 100%);
  --bg: #0f0f17;
  --bg-gradient: radial-gradient(ellipse at top left, #1a1a2e 0%, #0f0f17 60%);
  --card-bg: rgba(255,255,255,.04);
  --card-hover: rgba(255,255,255,.07);
  --border: rgba(255,255,255,.08);
  --border-accent: rgba(99,102,241,.4);
  --input-bg: rgba(255,255,255,.05);
  --text-primary: #f1f1f5;
  --text-secondary: #a1a1b5;
  --text-muted: #6b6b80;
  --sidebar-w: 260px;
  --topbar-h: 64px;
  --shadow: 0 4px 16px rgba(0,0,0,.35);
  --shadow-lg: 0 12px 48px rgba(0,0,0,.5);
  --radius: 14px;
  --radius-sm: 8px;
}

*,*::before,*::after { box-sizing: border-box; margin: 0; padding: 0; }

html { font-size: 16px; }

body {
  font-family: 'Inter', system-ui, sans-serif;
  background: var(--bg);
  color: var(--text-primary);
  min-height: 100vh;
  -webkit-font-smoothing: antialiased;
}

/* ── Scrollbar ─────────────────────────────────────────── */
::-webkit-scrollbar { width: 6px; }
::-webkit-scrollbar-track { background: transparent; }
::-webkit-scrollbar-thumb { background: rgba(255,255,255,.12); border-radius: 3px; }

/* ── Buttons ───────────────────────────────────────────── */
.btn {
  display: inline-flex;
  align-items: center;
  gap: .45rem;
  padding: .55rem 1rem;
  border-radius: var(--radius-sm);
  font-size: .875rem;
  font-weight: 500;
  font-family: inherit;
  cursor: pointer;
  border: none;
  transition: all .15s;
  text-decoration: none;
  white-space: nowrap;
}
.btn-primary  { background: var(--accent-gradient); color: #fff; box-shadow: 0 2px 12px rgba(99,102,241,.3); }
.btn-primary:hover  { opacity: .88; transform: translateY(-1px); }
.btn-ghost   { background: transparent; color: var(--text-secondary); border: 1px solid var(--border); }
.btn-ghost:hover   { background: var(--card-hover); color: var(--text-primary); }
.btn-danger  { background: rgba(239,68,68,.12); color: #f87171; border: 1px solid rgba(239,68,68,.25); }
.btn-danger:hover  { background: rgba(239,68,68,.22); }
.btn-icon { padding: .5rem; border-radius: var(--radius-sm); background: transparent; border: 1px solid var(--border); color: var(--text-secondary); cursor: pointer; display: inline-flex; align-items: center; justify-content: center; transition: all .15s; font-family: inherit; }
.btn-icon:hover { background: var(--card-hover); color: var(--text-primary); }
.btn-icon svg { width: 16px; height: 16px; }
.btn-sm { padding: .4rem .75rem; font-size: .8rem; }

/* ── App Layout ────────────────────────────────────────── */
.app-layout {
  display: grid;
  grid-template-columns: var(--sidebar-w) 1fr;
  grid-template-rows: var(--topbar-h) 1fr;
  min-height: 100vh;
}

/* ── Topbar ─────────────────────────────────────────────── */
.topbar {
  grid-column: 1 / -1;
  height: var(--topbar-h);
  background: rgba(15,15,23,.85);
  backdrop-filter: blur(16px);
  border-bottom: 1px solid var(--border);
  display: flex;
  align-items: center;
  padding: 0 1.25rem;
  gap: 1rem;
  position: sticky;
  top: 0;
  z-index: 50;
}

.topbar-brand {
  display: flex;
  align-items: center;
  gap: .6rem;
  font-weight: 700;
  font-size: 1.05rem;
  min-width: calc(var(--sidebar-w) - 1.25rem);
}
.topbar-brand .logo-icon {
  width: 36px; height: 36px;
  background: var(--accent-gradient);
  border-radius: 10px;
  display: flex; align-items: center; justify-content: center;
  font-size: 1.1rem;
}

.topbar-search {
  flex: 1;
  max-width: 420px;
  position: relative;
}
.topbar-search input {
  width: 100%;
  background: var(--input-bg);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: .55rem .9rem .55rem 2.5rem;
  color: var(--text-primary);
  font-family: inherit;
  font-size: .875rem;
  transition: border-color .2s;
}
.topbar-search input:focus { outline: none; border-color: var(--border-accent); }
.topbar-search .search-icon {
  position: absolute;
  left: .75rem; top: 50%;
  transform: translateY(-50%);
  color: var(--text-muted);
  pointer-events: none;
}

.topbar-spacer { flex: 1; }

.topbar-actions { display: flex; align-items: center; gap: .5rem; }

.user-avatar {
  width: 36px; height: 36px;
  border-radius: 50%;
  display: flex; align-items: center; justify-content: center;
  font-weight: 600;
  font-size: .9rem;
  cursor: pointer;
  border: 2px solid transparent;
  transition: border-color .2s;
  color: #fff;
  position: relative;
}
.user-avatar:hover { border-color: var(--accent); }

.hamburger { display: none; background: none; border: none; color: var(--text-primary); cursor: pointer; padding: .4rem; }

/* ── Sidebar ─────────────────────────────────────────────── */
.sidebar {
  background: rgba(255,255,255,.025);
  border-right: 1px solid var(--border);
  overflow-y: auto;
  padding: 1rem .75rem;
  display: flex;
  flex-direction: column;
  gap: .25rem;
}

.sidebar-section-title {
  font-size: .7rem;
  font-weight: 600;
  letter-spacing: .08em;
  text-transform: uppercase;
  color: var(--text-muted);
  padding: .75rem .5rem .35rem;
}

.sidebar-item {
  display: flex;
  align-items: center;
  gap: .6rem;
  padding: .5rem .65rem;
  border-radius: var(--radius-sm);
  color: var(--text-secondary);
  font-size: .875rem;
  cursor: pointer;
  transition: all .15s;
  user-select: none;
  border: none;
  background: none;
  width: 100%;
  text-align: left;
  font-family: inherit;
}
.sidebar-item:hover { background: var(--card-hover); color: var(--text-primary); }
.sidebar-item.active { background: rgba(99,102,241,.18); color: var(--accent); }
.sidebar-item .item-icon { width: 18px; flex-shrink: 0; text-align: center; }
.sidebar-item .item-count {
  margin-left: auto;
  font-size: .75rem;
  background: rgba(255,255,255,.07);
  border-radius: 99px;
  padding: .1rem .45rem;
  color: var(--text-muted);
}
.sidebar-item .item-indent { width: 16px; flex-shrink: 0; }

.sidebar-folder-row { display: flex; align-items: center; width: 100%; }
.sidebar-folder-row .btn-add-sub {
  margin-left: auto;
  opacity: 0;
  padding: .2rem .35rem;
  font-size: .75rem;
  border-radius: 5px;
  background: none;
  border: 1px solid transparent;
  color: var(--text-muted);
  cursor: pointer;
  transition: all .15s;
  font-family: inherit;
  flex-shrink: 0;
}
.sidebar-item:hover .btn-add-sub { opacity: 1; border-color: var(--border); }
.sidebar-folder-row .btn-add-sub:hover { background: var(--card-hover); color: var(--text-primary); }

.sidebar-divider { height: 1px; background: var(--border); margin: .5rem 0; }

/* ── Main ────────────────────────────────────────────────── */
.main {
  overflow-y: auto;
  padding: 1.5rem;
  display: flex;
  flex-direction: column;
  gap: 1.25rem;
}

/* ── Breadcrumb ──────────────────────────────────────────── */
.breadcrumb {
  display: flex;
  align-items: center;
  gap: .35rem;
  flex-wrap: wrap;
  font-size: .875rem;
}
.breadcrumb-item { color: var(--text-muted); cursor: pointer; transition: color .15s; }
.breadcrumb-item:hover { color: var(--text-primary); }
.breadcrumb-item.active { color: var(--text-primary); font-weight: 500; cursor: default; }
.breadcrumb-sep { color: var(--text-muted); }

/* ── Toolbar ─────────────────────────────────────────────── */
.toolbar {
  display: flex;
  align-items: center;
  gap: .75rem;
  flex-wrap: wrap;
}
.toolbar-left { display: flex; align-items: center; gap: .75rem; flex: 1; flex-wrap: wrap; }
.toolbar-right { display: flex; align-items: center; gap: .5rem; }

.view-toggle { display: flex; background: var(--input-bg); border: 1px solid var(--border); border-radius: var(--radius-sm); overflow: hidden; }
.view-toggle button { background: none; border: none; padding: .45rem .65rem; cursor: pointer; color: var(--text-muted); transition: all .15s; font-family: inherit; }
.view-toggle button.active { background: var(--accent); color: #fff; }

/* ── Upload-Drop-Zone ────────────────────────────────────── */
.drop-zone {
  border: 2px dashed var(--border);
  border-radius: var(--radius);
  padding: 2.5rem;
  text-align: center;
  color: var(--text-muted);
  cursor: pointer;
  transition: all .2s;
  position: relative;
}
.drop-zone:hover, .drop-zone.dragging {
  border-color: var(--accent);
  background: rgba(99,102,241,.05);
  color: var(--text-secondary);
}
.drop-zone input[type=file] { position: absolute; inset: 0; opacity: 0; cursor: pointer; width: 100%; height: 100%; }
.drop-zone .drop-icon { font-size: 2rem; margin-bottom: .75rem; }
.drop-zone p { font-size: .875rem; }
.drop-zone .drop-sub { font-size: .8rem; margin-top: .25rem; opacity: .6; }

/* ── Photo Grid ──────────────────────────────────────────── */
.photo-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
  gap: .75rem;
}
.photo-grid.list-view {
  grid-template-columns: 1fr;
  gap: .4rem;
}

.photo-card {
  background: var(--card-bg);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  overflow: hidden;
  cursor: pointer;
  transition: transform .18s, box-shadow .18s, border-color .18s;
  position: relative;
}
.photo-card:hover { transform: translateY(-3px); box-shadow: var(--shadow-lg); border-color: var(--border-accent); }

.photo-card .thumb {
  width: 100%;
  padding-bottom: 75%;
  position: relative;
  overflow: hidden;
  background: rgba(255,255,255,.03);
}
.photo-card .thumb img {
  position: absolute;
  inset: 0;
  width: 100%; height: 100%;
  object-fit: cover;
  transition: transform .3s;
}
.photo-card:hover .thumb img { transform: scale(1.05); }

.photo-card .card-overlay {
  position: absolute;
  bottom: 0; left: 0; right: 0;
  background: linear-gradient(to top, rgba(0,0,0,.75) 0%, transparent 100%);
  padding: .6rem .75rem .5rem;
  opacity: 0;
  transition: opacity .2s;
}
.photo-card:hover .card-overlay { opacity: 1; }
.card-overlay .card-actions { display: flex; gap: .35rem; justify-content: flex-end; }
.card-overlay .card-actions button {
  background: rgba(255,255,255,.15);
  border: none;
  border-radius: 6px;
  color: #fff;
  padding: .35rem .5rem;
  cursor: pointer;
  font-size: .75rem;
  transition: background .15s;
  font-family: inherit;
}
.card-overlay .card-actions button:hover { background: rgba(255,255,255,.3); }

.photo-card .card-info { padding: .6rem .75rem; }
.photo-card .card-name { font-size: .8rem; color: var(--text-secondary); white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
.photo-card .card-meta { font-size: .7rem; color: var(--text-muted); margin-top: .15rem; display: flex; gap: .5rem; align-items: center; }
.card-owner-dot { width: 8px; height: 8px; border-radius: 50%; display: inline-block; }

.photo-card.list-view-card {
  display: grid;
  grid-template-columns: 56px 1fr auto;
  align-items: center;
  gap: .75rem;
  padding: .5rem .75rem;
}
.photo-card.list-view-card .thumb { width: 56px; height: 42px; padding-bottom: 0; border-radius: 6px; flex-shrink: 0; }
.photo-card.list-view-card .thumb img { position: static; width: 100%; height: 100%; border-radius: 6px; }
.photo-card.list-view-card .card-overlay { display: none; }
.photo-card.list-view-card .card-info { padding: 0; }
.photo-card.list-view-card .list-actions { display: flex; gap: .35rem; }
.photo-card.list-view-card .list-actions button {
  background: none; border: 1px solid var(--border); border-radius: 6px;
  color: var(--text-muted); padding: .3rem .45rem; cursor: pointer; font-size: .75rem; transition: all .15s; font-family: inherit;
}
.photo-card.list-view-card .list-actions button:hover { background: var(--card-hover); color: var(--text-primary); }

/* ── Folder cards ────────────────────────────────────────── */
.folder-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(180px, 1fr));
  gap: .6rem;
  margin-bottom: .5rem;
}
.folder-card {
  background: var(--card-bg);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1rem;
  cursor: pointer;
  transition: all .18s;
  display: flex;
  align-items: center;
  gap: .75rem;
  position: relative;
}
.folder-card:hover { background: var(--card-hover); border-color: var(--border-accent); }
.folder-card .folder-icon { font-size: 1.5rem; flex-shrink: 0; }
.folder-card .folder-name { font-size: .875rem; font-weight: 500; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.folder-card .folder-count { font-size: .75rem; color: var(--text-muted); }
.folder-card .folder-menu {
  position: absolute; top: .5rem; right: .5rem;
  opacity: 0; transition: opacity .15s;
}
.folder-card:hover .folder-menu { opacity: 1; }
.folder-card .folder-menu button { background: none; border: none; color: var(--text-muted); cursor: pointer; padding: .25rem .35rem; border-radius: 5px; font-family: inherit; }
.folder-card .folder-menu button:hover { background: rgba(255,255,255,.1); color: var(--text-primary); }

/* ── Empty state ─────────────────────────────────────────── */
.empty-state {
  text-align: center;
  padding: 4rem 2rem;
  color: var(--text-muted);
}
.empty-state .empty-icon { font-size: 3.5rem; margin-bottom: 1rem; opacity: .4; }
.empty-state h3 { font-size: 1.1rem; color: var(--text-secondary); margin-bottom: .5rem; }
.empty-state p { font-size: .875rem; }

/* ── Modal ───────────────────────────────────────────────── */
.modal-overlay {
  position: fixed; inset: 0;
  background: rgba(0,0,0,.65);
  backdrop-filter: blur(6px);
  z-index: 100;
  display: flex; align-items: center; justify-content: center;
  padding: 1rem;
  opacity: 0; pointer-events: none;
  transition: opacity .2s;
}
.modal-overlay.open { opacity: 1; pointer-events: all; }

.modal {
  background: #1a1a2e;
  border: 1px solid var(--border);
  border-radius: 18px;
  padding: 1.75rem;
  width: 100%;
  max-width: 440px;
  box-shadow: var(--shadow-lg);
  transform: translateY(16px) scale(.97);
  transition: transform .2s;
}
.modal-overlay.open .modal { transform: none; }
.modal h2 { font-size: 1.2rem; margin-bottom: 1.25rem; }
.modal .modal-actions { display: flex; gap: .5rem; justify-content: flex-end; margin-top: 1.5rem; }
.modal .form-group { margin-bottom: 1rem; }
.modal .form-group label { display: block; font-size: .8rem; color: var(--text-secondary); margin-bottom: .4rem; }
.modal .form-group input, .modal .form-group select {
  width: 100%; padding: .65rem .85rem;
  background: var(--input-bg); border: 1.5px solid var(--border);
  border-radius: 8px; color: var(--text-primary); font-size: .9rem; font-family: inherit;
  transition: border-color .2s;
}
.modal .form-group input:focus, .modal .form-group select:focus { outline: none; border-color: var(--border-accent); }
.modal .form-group select option { background: #1a1a2e; }

/* ── Lightbox ────────────────────────────────────────────── */
.lightbox {
  position: fixed; inset: 0;
  background: rgba(0,0,0,.92);
  z-index: 200;
  display: flex;
  flex-direction: column;
  opacity: 0; pointer-events: none;
  transition: opacity .2s;
}
.lightbox.open { opacity: 1; pointer-events: all; }

.lightbox-header {
  display: flex;
  align-items: center;
  gap: 1rem;
  padding: 1rem 1.25rem;
  background: rgba(0,0,0,.4);
}
.lightbox-header .lb-title { flex: 1; font-size: .9rem; color: var(--text-secondary); overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.lightbox-header .lb-actions { display: flex; gap: .5rem; }
.lightbox-header .lb-actions button {
  background: rgba(255,255,255,.08);
  border: 1px solid rgba(255,255,255,.12);
  border-radius: 8px; color: #fff; padding: .45rem .8rem;
  cursor: pointer; font-size: .8rem; transition: background .15s; font-family: inherit;
}
.lightbox-header .lb-actions button:hover { background: rgba(255,255,255,.18); }
.lightbox-close { background: none; border: none; color: var(--text-muted); cursor: pointer; font-size: 1.25rem; padding: .25rem; transition: color .15s; }
.lightbox-close:hover { color: #fff; }

.lightbox-body {
  flex: 1;
  display: flex;
  align-items: center;
  justify-content: center;
  position: relative;
  overflow: hidden;
}
.lightbox-body img {
  max-width: 100%; max-height: 100%;
  object-fit: contain;
  border-radius: 4px;
}
.lb-nav {
  position: absolute;
  top: 50%; transform: translateY(-50%);
  background: rgba(255,255,255,.08);
  border: 1px solid rgba(255,255,255,.12);
  border-radius: 50%;
  width: 44px; height: 44px;
  display: flex; align-items: center; justify-content: center;
  cursor: pointer;
  color: #fff;
  transition: background .15s;
  font-size: 1.1rem;
}
.lb-nav:hover { background: rgba(255,255,255,.2); }
.lb-prev { left: 1rem; }
.lb-next { right: 1rem; }

.lightbox-counter { font-size: .8rem; color: var(--text-muted); text-align: center; padding: .75rem; }

/* ── Upload progress ─────────────────────────────────────── */
.upload-progress {
  position: fixed;
  bottom: 1.5rem; right: 1.5rem;
  background: #1a1a2e;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1rem 1.25rem;
  min-width: 280px;
  box-shadow: var(--shadow-lg);
  z-index: 150;
  display: none;
}
.upload-progress.show { display: block; }
.upload-progress h4 { font-size: .85rem; margin-bottom: .75rem; }
.progress-bar { height: 6px; background: rgba(255,255,255,.08); border-radius: 3px; overflow: hidden; }
.progress-fill { height: 100%; background: var(--accent-gradient); border-radius: 3px; transition: width .3s; }
.progress-text { font-size: .75rem; color: var(--text-muted); margin-top: .45rem; }

/* ── Toast ───────────────────────────────────────────────── */
.toast-container { position: fixed; bottom: 1.5rem; left: 50%; transform: translateX(-50%); z-index: 300; display: flex; flex-direction: column; gap: .5rem; align-items: center; pointer-events: none; }
.toast {
  background: #2a2a3e; border: 1px solid var(--border); border-radius: 10px;
  padding: .65rem 1.1rem; font-size: .875rem; color: var(--text-primary);
  box-shadow: var(--shadow); animation: slideUp .25s ease; pointer-events: all;
}
.toast.success { border-color: rgba(34,197,94,.35); color: #86efac; }
.toast.error { border-color: rgba(239,68,68,.35); color: #fca5a5; }
@keyframes slideUp { from { opacity:0; transform:translateY(12px); } to { opacity:1; transform:none; } }

/* ── Context Menu ────────────────────────────────────────── */
.ctx-menu {
  position: fixed;
  background: #1e1e30;
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  padding: .35rem;
  min-width: 160px;
  box-shadow: var(--shadow-lg);
  z-index: 400;
  display: none;
}
.ctx-menu.open { display: block; }
.ctx-item {
  padding: .55rem .85rem;
  font-size: .85rem;
  cursor: pointer;
  border-radius: 5px;
  display: flex; align-items: center; gap: .6rem;
  color: var(--text-secondary);
  transition: all .12s;
}
.ctx-item:hover { background: var(--card-hover); color: var(--text-primary); }
.ctx-item.danger:hover { background: rgba(239,68,68,.12); color: #f87171; }
.ctx-divider { height: 1px; background: var(--border); margin: .3rem 0; }

/* ── Share badge ─────────────────────────────────────────── */
.share-badge {
  position: absolute;
  top: .5rem; left: .5rem;
  background: var(--accent-gradient);
  border-radius: 5px;
  padding: .15rem .4rem;
  font-size: .65rem;
  font-weight: 600;
  color: #fff;
  letter-spacing: .03em;
}

/* ── Responsive ──────────────────────────────────────────── */
@media (max-width: 768px) {
  :root { --sidebar-w: 0px; }

  .app-layout { grid-template-columns: 1fr; }

  .sidebar {
    position: fixed;
    left: 0; top: var(--topbar-h);
    bottom: 0; width: 260px;
    z-index: 60;
    transform: translateX(-100%);
    transition: transform .25s;
    background: #0f0f17;
  }
  .sidebar.mobile-open { transform: none; }
  .sidebar-backdrop {
    position: fixed; inset: 0;
    background: rgba(0,0,0,.5);
    z-index: 55;
    display: none;
  }
  .sidebar-backdrop.show { display: block; }

  .hamburger { display: flex; }
  .topbar-brand { min-width: auto; }
  .topbar-search { display: none; }

  .main { padding: 1rem; }

  .photo-grid { grid-template-columns: repeat(auto-fill, minmax(140px, 1fr)); gap: .5rem; }
  .folder-grid { grid-template-columns: repeat(auto-fill, minmax(140px, 1fr)); }

  .lb-nav { width: 36px; height: 36px; font-size: .9rem; }
}

@media (max-width: 480px) {
  .photo-grid { grid-template-columns: repeat(2, 1fr); }
}

/* ── Skeleton loader ─────────────────────────────────────── */
.skeleton {
  background: linear-gradient(90deg, rgba(255,255,255,.04) 25%, rgba(255,255,255,.08) 50%, rgba(255,255,255,.04) 75%);
  background-size: 200% 100%;
  animation: shimmer 1.5s infinite;
  border-radius: var(--radius-sm);
}
@keyframes shimmer { from { background-position: 200% 0; } to { background-position: -200% 0; } }

/* ── Section header ──────────────────────────────────────── */
.section-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: .75rem;
}
.section-header h2 { font-size: 1rem; font-weight: 600; color: var(--text-secondary); }

/* ── Stats bar ───────────────────────────────────────────── */
.stats-bar {
  display: flex;
  gap: .75rem;
  flex-wrap: wrap;
}
.stat-chip {
  background: var(--card-bg);
  border: 1px solid var(--border);
  border-radius: 99px;
  padding: .3rem .8rem;
  font-size: .78rem;
  color: var(--text-muted);
  display: flex;
  align-items: center;
  gap: .35rem;
}