*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
:root {
  --blue: #1a73e8; --blue-light: #e8f0fe; --gray: #5f6368; --border: #e0e0e0;
  --bg: #f8f9fa; --white: #fff; --text: #202124; --red: #d93025;
  --sidebar-w: 240px; --header-h: 64px;
}
body { font-family: 'Google Sans',Roboto,Arial,sans-serif; color: var(--text); background: var(--bg); height: 100vh; display: flex; flex-direction: column; overflow: hidden; }

/* ── login ── */
#login-screen { display:flex; align-items:center; justify-content:center; height:100vh; background:var(--bg); }
.login-box { background:var(--white); border-radius:8px; padding:40px; width:360px; box-shadow:0 2px 10px rgba(0,0,0,.12); }
.login-box h1 { font-size:22px; font-weight:500; margin-bottom:8px; color:var(--blue); }
.login-box p { color:var(--gray); font-size:14px; margin-bottom:24px; }
.login-box input { width:100%; padding:10px 12px; border:1px solid var(--border); border-radius:4px; font-size:14px; margin-bottom:14px; outline:none; transition:border .2s; }
.login-box input:focus { border-color:var(--blue); }
.login-box button { width:100%; padding:10px; background:var(--blue); color:#fff; border:none; border-radius:4px; font-size:14px; cursor:pointer; }
.login-box button:hover { background:#1557b0; }
#login-err { color:var(--red); font-size:13px; margin-top:10px; display:none; }

/* ── header ── */
header { height:var(--header-h); background:var(--white); border-bottom:1px solid var(--border); display:flex; align-items:center; padding:0 16px; gap:12px; z-index:100; flex-shrink:0; }
.logo { display:flex; align-items:center; gap:8px; font-size:20px; font-weight:500; color:var(--blue); text-decoration:none; width:var(--sidebar-w); flex-shrink:0; }
.logo svg { width:32px; height:32px; }
.search-wrap { flex:1; max-width:720px; position:relative; }
.search-wrap input { width:100%; padding:10px 16px 10px 44px; background:var(--bg); border:1px solid transparent; border-radius:24px; font-size:14px; outline:none; transition:all .2s; }
.search-wrap input:focus { background:#fff; border-color:var(--blue); box-shadow:0 1px 6px rgba(32,33,36,.2); }
.search-wrap svg { position:absolute; left:14px; top:50%; transform:translateY(-50%); color:var(--gray); }
.header-actions { display:flex; align-items:center; gap:8px; margin-left:auto; }
.avatar { width:36px; height:36px; border-radius:50%; background:var(--blue); color:#fff; display:flex; align-items:center; justify-content:center; font-size:15px; font-weight:500; cursor:pointer; user-select:none; position:relative; }
.user-menu { position:absolute; top:44px; right:0; background:#fff; border-radius:8px; box-shadow:0 4px 20px rgba(0,0,0,.15); min-width:200px; z-index:200; display:none; overflow:hidden; }
.user-menu.open { display:block; }
.user-menu-info { padding:16px; border-bottom:1px solid var(--border); }
.user-menu-info strong { display:block; font-size:14px; }
.user-menu-info span { font-size:12px; color:var(--gray); }
.user-menu a { display:block; padding:10px 16px; font-size:13px; color:var(--text); text-decoration:none; cursor:pointer; }
.user-menu a:hover { background:var(--bg); }

/* ── layout ── */
.app-body { display:flex; flex:1; overflow:hidden; }

/* ── sidebar ── */
nav { width:var(--sidebar-w); flex-shrink:0; padding:12px 8px; overflow-y:auto; background:var(--white); }
.btn-new { display:flex; align-items:center; gap:10px; padding:14px 20px; background:#fff; border:1px solid var(--border); border-radius:24px; cursor:pointer; font-size:14px; font-weight:500; margin:0 8px 16px; box-shadow:0 1px 3px rgba(0,0,0,.1); white-space:nowrap; }
.btn-new:hover { background:var(--bg); box-shadow:0 2px 6px rgba(0,0,0,.15); }
.btn-new svg { color:var(--blue); }
.nav-item { display:flex; align-items:center; gap:12px; padding:8px 16px; border-radius:0 24px 24px 0; cursor:pointer; font-size:13px; color:var(--text); transition:background .15s; margin-right:8px; }
.nav-item:hover { background:var(--bg); }
.nav-item.active { background:var(--blue-light); font-weight:500; color:var(--blue); }
.nav-item svg { width:20px; height:20px; flex-shrink:0; }
.quota-bar { margin:16px 16px 8px; }
.quota-bar .bar { height:4px; background:var(--border); border-radius:2px; overflow:hidden; }
.quota-bar .fill { height:100%; background:var(--blue); border-radius:2px; transition:width .3s; }
.quota-bar p { font-size:11px; color:var(--gray); margin-top:6px; }

/* ── main ── */
main { flex:1; display:flex; flex-direction:column; overflow:hidden; padding:0; }
.toolbar { display:flex; align-items:center; gap:8px; padding:12px 20px; flex-shrink:0; }
.breadcrumb { display:flex; align-items:center; gap:4px; flex:1; flex-wrap:wrap; }
.breadcrumb span { font-size:16px; font-weight:500; cursor:pointer; color:var(--text); }
.breadcrumb span:hover { color:var(--blue); }
.breadcrumb .sep { color:var(--gray); }
.toolbar-right { display:flex; gap:8px; align-items:center; }
.icon-btn { padding:6px; border:none; background:none; cursor:pointer; border-radius:50%; color:var(--gray); display:flex; align-items:center; justify-content:center; }
.icon-btn:hover { background:var(--bg); }

/* ── file grid ── */
.files-area { flex:1; overflow-y:auto; padding:8px 20px 20px; }
.section-label { font-size:12px; color:var(--gray); font-weight:500; padding:8px 0 4px; text-transform:uppercase; letter-spacing:.5px; }
.file-grid { display:grid; grid-template-columns:repeat(auto-fill,minmax(200px,1fr)); gap:8px; margin-bottom:24px; }
.file-card { padding:12px; border-radius:8px; cursor:pointer; border:1px solid transparent; transition:all .15s; position:relative; display:flex; flex-direction:column; gap:8px; background:#fff; }
.file-card:hover { background:var(--blue-light); border-color:var(--blue-light); }
.file-card.selected { background:var(--blue-light); border-color:#aecbfa; }
.file-card .icon { font-size:36px; line-height:1; }
.file-card .name { font-size:13px; font-weight:500; word-break:break-word; overflow:hidden; display:-webkit-box; -webkit-line-clamp:2; -webkit-box-orient:vertical; }
.file-card .meta { font-size:11px; color:var(--gray); }
.file-card .card-menu-btn { position:absolute; top:6px; right:6px; opacity:0; padding:4px; border-radius:50%; background:rgba(255,255,255,.9); border:none; cursor:pointer; display:flex; }
.file-card:hover .card-menu-btn { opacity:1; }

/* ── list view ── */
.file-list { width:100%; border-collapse:collapse; }
.file-list th { font-size:12px; color:var(--gray); font-weight:500; text-align:left; padding:6px 12px; border-bottom:1px solid var(--border); }
.file-list td { padding:6px 12px; font-size:13px; border-bottom:1px solid var(--border); }
.file-list tr:hover td { background:var(--bg); }
.file-list tr.selected td { background:var(--blue-light); }
.file-list .col-name { display:flex; align-items:center; gap:10px; cursor:pointer; }
.file-list .icon-sm { font-size:20px; }
.file-list td:last-child { text-align:right; }

/* ── context menu ── */
#ctx-menu { position:fixed; background:#fff; border-radius:8px; box-shadow:0 4px 20px rgba(0,0,0,.2); z-index:1000; min-width:180px; padding:6px 0; display:none; }
#ctx-menu.open { display:block; }
#ctx-menu .ctx-item { display:flex; align-items:center; gap:12px; padding:9px 16px; font-size:13px; cursor:pointer; }
#ctx-menu .ctx-item:hover { background:var(--bg); }
#ctx-menu .ctx-item svg { color:var(--gray); width:16px; height:16px; }
#ctx-menu .ctx-sep { height:1px; background:var(--border); margin:4px 0; }

/* ── modals ── */
.modal-overlay { position:fixed; inset:0; background:rgba(0,0,0,.4); z-index:500; display:none; align-items:center; justify-content:center; }
.modal-overlay.open { display:flex; }
.modal { background:#fff; border-radius:12px; padding:28px; width:440px; max-width:96vw; box-shadow:0 8px 40px rgba(0,0,0,.2); }
.modal h2 { font-size:18px; font-weight:500; margin-bottom:16px; }
.modal input, .modal select { width:100%; padding:10px 12px; border:1px solid var(--border); border-radius:4px; font-size:14px; margin-bottom:12px; outline:none; }
.modal input:focus { border-color:var(--blue); }
.modal .modal-actions { display:flex; justify-content:flex-end; gap:8px; margin-top:8px; }
.btn { padding:8px 20px; border-radius:4px; font-size:14px; cursor:pointer; border:none; }
.btn-primary { background:var(--blue); color:#fff; }
.btn-primary:hover { background:#1557b0; }
.btn-ghost { background:none; color:var(--blue); }
.btn-ghost:hover { background:var(--blue-light); }
.share-row { display:flex; align-items:center; justify-content:space-between; padding:8px 0; border-bottom:1px solid var(--border); font-size:13px; }
.share-row .share-badge { font-size:11px; background:var(--bg); border:1px solid var(--border); border-radius:12px; padding:2px 8px; }
.share-link-box { display:flex; gap:8px; margin-top:8px; }
.share-link-box input { flex:1; font-size:12px; }
.copy-btn { padding:8px 14px; background:var(--blue); color:#fff; border:none; border-radius:4px; cursor:pointer; font-size:13px; white-space:nowrap; }
.tab-bar { display:flex; border-bottom:1px solid var(--border); margin-bottom:16px; }
.tab { padding:8px 16px; font-size:13px; cursor:pointer; border-bottom:2px solid transparent; }
.tab.active { border-color:var(--blue); color:var(--blue); }

/* ── upload progress ── */
#upload-panel { position:fixed; bottom:16px; right:16px; width:320px; background:#fff; border-radius:8px; box-shadow:0 4px 20px rgba(0,0,0,.2); z-index:400; display:none; overflow:hidden; }
#upload-panel.open { display:block; }
#upload-panel header { padding:12px 16px; background:var(--blue); color:#fff; font-size:13px; font-weight:500; display:flex; justify-content:space-between; cursor:pointer; }
.upload-item { padding:10px 16px; border-bottom:1px solid var(--border); font-size:13px; }
.upload-item .uname { overflow:hidden; text-overflow:ellipsis; white-space:nowrap; margin-bottom:4px; }
.upload-progress { height:4px; background:var(--border); border-radius:2px; overflow:hidden; }
.upload-progress .fill { height:100%; background:var(--blue); transition:width .2s; }
.upload-item.done .fill { background:#1e8e3e; }
.upload-item.err .fill { background:var(--red); }

/* ── empty state ── */
.empty { display:flex; flex-direction:column; align-items:center; justify-content:center; height:60%; gap:16px; color:var(--gray); }
.empty svg { width:80px; height:80px; opacity:.3; }
.empty p { font-size:15px; }

/* ── drop zone highlight ── */
.drop-active::after { content:'Drop files here'; position:fixed; inset:0; background:rgba(26,115,232,.12); border:3px dashed var(--blue); border-radius:8px; display:flex; align-items:center; justify-content:center; font-size:22px; color:var(--blue); z-index:300; pointer-events:none; display:flex; align-items:center; justify-content:center; }

/* ── admin panel ── */
.admin-table { width:100%; border-collapse:collapse; }
.admin-table th { text-align:left; padding:8px 12px; background:var(--bg); font-size:12px; color:var(--gray); }
.admin-table td { padding:8px 12px; font-size:13px; border-bottom:1px solid var(--border); }

/* ── toast ── */
#toast { position:fixed; bottom:80px; left:50%; transform:translateX(-50%); background:#323232; color:#fff; padding:10px 20px; border-radius:24px; font-size:13px; z-index:600; opacity:0; transition:opacity .3s; pointer-events:none; }
#toast.show { opacity:1; }

@media(max-width:600px) {
  nav { display:none; }
  .logo { width:auto; }
}