/* ─── CSS Variables / Dark Mode ─── */
:root, [data-theme="light"] {
  --bg: #f5f6fa; --card: #fff; --text: #2c3e50; --muted: #7f8c8d;
  --border: #e8ecf1; --hover: #f1f5f9; --accent: #4a6cf7; --accent2: #667eea;
  --grad: linear-gradient(135deg, #667eea, #764ba2);
  --shadow: 0 1px 3px rgba(0,0,0,.06);
  --shadow-hover: 0 8px 24px rgba(0,0,0,.08);
  --nav-bg: #fff; --input-bg: #fafbfc;
}
[data-theme="dark"] {
  --bg: #0f1117; --card: #1a1d27; --text: #e4e6eb; --muted: #8b8fa3;
  --border: #2d3140; --hover: #252836; --accent: #5b7cfa; --accent2: #7c8cf5;
  --grad: linear-gradient(135deg, #5b7cfa, #8b5cf6);
  --shadow: 0 1px 3px rgba(0,0,0,.3);
  --shadow-hover: 0 8px 24px rgba(0,0,0,.4);
  --nav-bg: #1a1d27; --input-bg: #252836;
}

/* ─── Reset ─── */
*{margin:0;padding:0;box-sizing:border-box}
html{font-size:16px}
body{font-family:-apple-system,BlinkMacSystemFont,'Segoe UI',Roboto,Oxygen,Ubuntu,sans-serif;background:var(--bg);color:var(--text);min-height:100vh;line-height:1.5;transition:background .3s,color .3s}
a{color:var(--accent);text-decoration:none}
a:hover{text-decoration:underline}
button{cursor:pointer;font-family:inherit;border:0;transition:all .2s ease}
button:focus-visible{outline:2px solid var(--accent);outline-offset:2px}
input,select{font-family:inherit;transition:border-color .2s ease}
input:focus,select:focus{outline:0;border-color:var(--accent);box-shadow:0 0 0 3px rgba(74,108,247,.12)}

/* ─── Common ─── */
.page{display:none}.page.active{display:block}
.empty-state{text-align:center;padding:40px;color:var(--muted);grid-column:1/-1;font-size:14px}
.icon-btn{background:transparent;color:var(--text);width:32px;height:32px;border-radius:8px;font-size:16px;display:inline-flex;align-items:center;justify-content:center;padding:0}
.icon-btn:hover{background:var(--hover)}

/* ─── Auth ─── */
.page.active.auth-page{display:flex;align-items:center;justify-content:center;min-height:100vh;padding:24px;background:linear-gradient(135deg,#667eea 0%,#764ba2 100%)}
.auth-card{background:#fff;border-radius:16px;padding:40px;width:100%;max-width:420px;box-shadow:0 20px 60px rgba(0,0,0,.15)}
.auth-card h1{font-size:28px;text-align:center;background:var(--grad);-webkit-background-clip:text;-webkit-text-fill-color:transparent;margin-bottom:4px}
.subtitle{text-align:center;color:#7f8c8d;margin-bottom:28px;font-size:14px}
.auth-card input{width:100%;padding:12px 16px;margin-bottom:14px;border:2px solid #e8ecf1;border-radius:10px;font-size:15px;background:#fafbfc;color:#2c3e50}
.auth-card input:focus{border-color:#4a6cf7;background:#fff}
.auth-card button[type=submit]{width:100%;padding:13px;background:linear-gradient(135deg,#667eea,#764ba2);color:#fff;border-radius:10px;font-size:16px;font-weight:600;margin-top:4px}
.auth-card button[type=submit]:hover{transform:translateY(-1px);box-shadow:0 8px 24px rgba(102,126,234,.35)}
.switch-link{text-align:center;margin-top:18px;font-size:14px;color:#7f8c8d}
.switch-link a{color:#667eea;font-weight:500}
.error-msg{color:#e74c3c;font-size:13px;margin-top:10px;text-align:center;min-height:20px}

/* ─── Navigation ─── */
nav{background:var(--nav-bg);border-bottom:1px solid var(--border);padding:0 24px;display:flex;justify-content:space-between;align-items:center;height:60px;position:sticky;top:0;z-index:50;transition:background .3s}
.nav-brand{font-size:20px;font-weight:700;background:var(--grad);-webkit-background-clip:text;-webkit-text-fill-color:transparent}
.nav-user{display:flex;align-items:center;gap:8px;font-size:14px}
.nav-user span{color:var(--muted)}
.nav-user a{color:var(--accent);font-weight:500;padding:6px 10px;border-radius:8px;transition:background .2s;white-space:nowrap}
.nav-user a:hover{background:var(--hover);text-decoration:none}

/* ─── Container ─── */
.container{max-width:1100px;margin:0 auto;padding:24px}

/* ─── Dashboard ─── */
.dashboard-header{display:flex;justify-content:space-between;align-items:center;margin-bottom:24px}
.dashboard-header h2{font-size:22px;font-weight:600}
.btn-primary{padding:10px 20px;background:var(--accent);color:#fff;border-radius:10px;font-size:14px;font-weight:600;white-space:nowrap}
.btn-primary:hover{filter:brightness(1.1);transform:translateY(-1px);box-shadow:0 4px 12px rgba(74,108,247,.3)}

/* ─── Folder Grid ─── */
.folder-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(220px,1fr));gap:16px}
.folder-card{background:var(--card);border-radius:12px;padding:20px;box-shadow:var(--shadow);cursor:pointer;transition:all .25s ease;position:relative;border:1px solid transparent}
.folder-card:hover{box-shadow:var(--shadow-hover);transform:translateY(-2px);border-color:var(--border)}
.folder-card-body{padding-right:32px}
.folder-card .icon{font-size:36px;margin-bottom:10px}
.folder-card .name{font-size:15px;font-weight:600;margin-bottom:4px}
.folder-card .meta{font-size:12px;color:var(--muted)}
.folder-actions{position:absolute;top:12px;right:12px;opacity:0;transition:opacity .2s}
.folder-card:hover .folder-actions{opacity:1}

/* ─── Breadcrumb & Folder Actions ─── */
.breadcrumb{font-size:14px;margin-bottom:16px;display:flex;flex-wrap:wrap;align-items:center;gap:4px}
.breadcrumb a{color:var(--accent);font-weight:500}
.breadcrumb a:hover{text-decoration:underline}
.crumb-sep{color:var(--muted);font-size:18px;line-height:1}
.crumb-current{font-weight:600;color:var(--text)}
.folder-actions-bar{display:flex;flex-wrap:wrap;gap:10px;align-items:center;margin-bottom:20px;padding-bottom:16px;border-bottom:1px solid var(--border)}
.sort-group,.filter-group{display:flex;align-items:center;gap:4px;flex-wrap:wrap}
.sort-label{font-size:12px;color:var(--muted);margin-right:2px}
.sort-btn,.filter-btn{background:transparent;color:var(--muted);padding:5px 10px;border-radius:6px;font-size:12px;font-weight:500}
.sort-btn.active,.filter-btn.active{background:var(--accent);color:#fff}
.sort-btn:hover,.filter-btn:hover{background:var(--hover);color:var(--text)}

/* ─── Upload ─── */
.upload-area{border:2px dashed var(--border);border-radius:12px;padding:36px 24px;text-align:center;margin-bottom:20px;cursor:pointer;transition:all .25s ease;background:var(--input-bg)}
.upload-area:hover{border-color:var(--accent);background:var(--hover)}
.upload-area input{display:none}
.upload-label{font-size:14px;color:var(--muted);cursor:pointer;display:flex;flex-direction:column;align-items:center;gap:8px}
.upload-label::before{content:'☁️';font-size:36px}

/* ─── Upload Progress ─── */
.upload-progress{background:var(--card);border-radius:10px;padding:14px 18px;margin-bottom:16px;box-shadow:var(--shadow);display:flex;align-items:center;gap:12px}
.progress-track{flex:1;background:var(--border);border-radius:6px;height:8px;overflow:hidden}
.progress-fill{background:var(--grad);border-radius:6px;height:100%;transition:width .3s ease}
.upload-progress span{font-size:13px;color:var(--muted);white-space:nowrap;min-width:180px}

/* ─── Batch Bar ─── */
.batch-bar{background:#eef2ff;border-radius:10px;padding:12px 18px;margin-bottom:16px;display:flex;align-items:center;gap:12px;border:1px solid #d0d5ff}
[data-theme="dark"] .batch-bar{background:#252836;border-color:#2d3140}
.batch-bar span{font-size:14px;font-weight:500;flex:1}
.batch-bar button{font-size:13px;padding:7px 16px;border-radius:8px;font-weight:500}
.btn-del{background:#fee2e2;color:#dc2626}
.btn-del:hover{background:#fecaca}
[data-theme="dark"] .btn-del{background:#3b1a1a;color:#f87171}
[data-theme="dark"] .btn-del:hover{background:#4f1f1f}
.btn-cancel{background:transparent;color:var(--muted)}
.btn-cancel:hover{background:var(--hover);color:var(--text)}

/* ─── File Grid ─── */
.file-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(200px,1fr));gap:16px}
.file-card{background:var(--card);border-radius:12px;overflow:hidden;box-shadow:var(--shadow);transition:all .25s ease;position:relative;border:1px solid transparent}
.file-card:hover{box-shadow:var(--shadow-hover);transform:translateY(-2px);border-color:var(--border)}
.file-thumb{width:100%;height:160px;display:flex;align-items:center;justify-content:center;background:var(--input-bg);font-size:40px;cursor:pointer;overflow:hidden}
.file-thumb img{width:100%;height:100%;object-fit:cover}
.file-check{position:absolute;top:8px;left:8px;z-index:2}
.file-check input{width:18px;height:18px;cursor:pointer;accent-color:var(--accent);border-radius:4px}
.file-card .info{padding:14px}
.file-card .info .name{font-size:14px;font-weight:600;word-break:break-all;cursor:pointer;color:var(--text)}
.file-card .info .name:hover{color:var(--accent)}
.file-card .info .size{font-size:12px;color:var(--muted);margin-top:3px}
.file-actions{display:flex;gap:4px;align-items:center;margin-top:8px;padding-top:8px;border-top:1px solid var(--border)}
.btn-icon{background:transparent;color:var(--muted);border-radius:6px;width:30px;height:30px;font-size:14px;display:inline-flex;align-items:center;justify-content:center;transition:all .15s}
.btn-icon:hover{background:var(--hover);color:var(--text)}
.btn-icon.delete:hover{background:#fee2e2;color:#dc2626}
[data-theme="dark"] .btn-icon.delete:hover{background:#3b1a1a;color:#f87171}
.btn-file{display:inline-flex;align-items:center;justify-content:center;padding:5px 12px;background:var(--accent);color:#fff;text-decoration:none;border-radius:6px;font-size:12px;font-weight:500;transition:all .15s;min-width:30px;height:30px}
.btn-file:hover{filter:brightness(1.1);color:#fff;text-decoration:none}

/* ─── Search ─── */
.search-bar{display:flex;gap:10px;align-items:center}
.search-results{display:flex;flex-direction:column;gap:8px}
.search-result-card{display:flex;align-items:center;gap:14px;background:var(--card);border-radius:10px;padding:14px 16px;box-shadow:var(--shadow);border:1px solid transparent;transition:all .2s}
.search-result-card:hover{border-color:var(--border);box-shadow:var(--shadow-hover)}
.search-thumb{font-size:28px;width:40px;text-align:center}
.search-info{flex:1;min-width:0}
.search-name{font-size:14px;font-weight:600;word-break:break-all}
.search-meta{font-size:12px;color:var(--muted);margin-top:2px}

/* ─── Modals ─── */
.modal{display:none;position:fixed;top:0;left:0;width:100%;height:100%;background:rgba(0,0,0,.45);z-index:100;align-items:center;justify-content:center;backdrop-filter:blur(4px)}
.modal.active{display:flex}
.modal-content{background:var(--card);border-radius:16px;padding:28px;max-width:440px;width:92%;box-shadow:0 24px 80px rgba(0,0,0,.2);animation:modalIn .25s ease}
@keyframes modalIn{from{opacity:0;transform:scale(.95) translateY(10px)}to{opacity:1;transform:scale(1) translateY(0)}}
.modal-content h3{font-size:18px;font-weight:600;margin-bottom:16px}
.modal-content input,.modal-select{width:100%;padding:11px 14px;border:2px solid var(--border);border-radius:10px;font-size:15px;margin-bottom:14px;background:var(--input-bg);color:var(--text)}
.modal-select{background:var(--input-bg);cursor:pointer;appearance:auto}
.modal-content input:focus,.modal-select:focus{border-color:var(--accent)}
.modal-actions{display:flex;gap:8px;justify-content:flex-end;margin-top:4px}
.modal-actions button{padding:10px 20px;border-radius:10px;font-size:14px;font-weight:500}
.modal-actions .btn-cancel{background:var(--hover);color:var(--muted)}
.modal-actions .btn-cancel:hover{background:var(--border)}
.modal-actions .btn-primary{background:var(--accent);color:#fff}
.modal-actions .btn-primary:hover{filter:brightness(1.1)}
.share-options{margin-bottom:16px}
.share-option-row{display:flex;align-items:center;gap:10px;margin-bottom:10px}
.share-option-row label{font-size:14px;font-weight:500;min-width:95px;color:var(--text)}
.share-option-row select{flex:1;padding:9px 12px;border:2px solid var(--border);border-radius:10px;font-size:14px;background:var(--input-bg);color:var(--text);cursor:pointer}
.share-option-row select:focus{border-color:var(--accent)}
.share-generate{margin-bottom:4px}
.share-generate .btn-primary{width:100%;justify-content:center}

/* ─── Preview ─── */
.modal-preview-content{max-width:90vw;max-height:90vh;padding:20px;overflow:auto;width:auto;border-radius:16px}
.preview-header{display:flex;justify-content:space-between;align-items:center;margin-bottom:14px}
.preview-header span{font-weight:600;font-size:16px;word-break:break-all}
.modal-close{background:0;border:0;font-size:28px;cursor:pointer;color:var(--muted);padding:0;width:36px;height:36px;display:flex;align-items:center;justify-content:center;border-radius:8px;transition:all .15s}
.modal-close:hover{background:var(--hover);color:var(--text)}
.preview-img{max-width:100%;max-height:68vh;display:block;margin:0 auto;border-radius:10px;box-shadow:0 4px 12px rgba(0,0,0,.1)}
.preview-actions{text-align:center;margin-top:14px}

/* ─── Account ─── */
.account-card{background:var(--card);border-radius:12px;padding:24px;margin-bottom:16px;box-shadow:var(--shadow)}
.account-card h3{font-size:16px;font-weight:600;margin-bottom:14px;padding-bottom:10px;border-bottom:1px solid var(--border)}
.account-row{display:flex;justify-content:space-between;align-items:center;padding:10px 0}
.account-row+.account-row{border-top:1px solid var(--border)}
.account-label{font-size:14px;color:var(--muted)}
.account-value{font-size:14px;font-weight:500;text-align:right;word-break:break-all;max-width:60%}
.account-card input{background:var(--input-bg);color:var(--text)}

/* ─── Share Page ─── */
.share-body{padding:32px 24px;max-width:900px;margin:0 auto;min-height:100vh;background:var(--bg)}
.share-body h1{font-size:28px;background:var(--grad);-webkit-background-clip:text;-webkit-text-fill-color:transparent;margin-bottom:4px}
.share-body .subtitle{color:var(--muted);margin-bottom:24px}
.share-file-card{background:var(--card);border-radius:12px;overflow:hidden;box-shadow:var(--shadow);transition:all .25s ease;border:1px solid transparent}
.share-file-card:hover{box-shadow:var(--shadow-hover);transform:translateY(-2px);border-color:var(--border)}
.share-file-card img{width:100%;height:180px;object-fit:cover}
.share-file-card .info{padding:14px}
.share-file-card .info .name{font-size:14px;font-weight:600;word-break:break-all}
.share-file-card .info .size{font-size:12px;color:var(--muted);margin-top:3px}
.share-file-card .info .btn-file{margin-top:8px;display:inline-block}
.share-upload-zone{border:2px dashed var(--border);border-radius:12px;padding:24px;text-align:center;margin-bottom:24px;background:var(--input-bg);transition:all .25s ease}
.share-upload-zone.dragover{border-color:var(--accent);background:var(--accent-light, #f0f2ff)}
.share-upload-zone p{font-weight:600;margin-bottom:8px;color:var(--text)}
.share-upload-zone .progress-bar{height:6px;background:var(--border);border-radius:3px;overflow:hidden;margin:12px 0 4px}
.share-upload-zone .progress-bar div{height:100%;background:var(--grad);border-radius:3px;transition:width .3s ease}
.share-upload-text{font-size:13px;color:var(--muted)}

/* ─── Trash ─── */
.trash-item{display:flex;align-items:center;gap:14px;background:var(--card);border-radius:10px;padding:12px 16px;box-shadow:var(--shadow);margin-bottom:8px;opacity:.7}
.trash-item .thumb{font-size:24px;width:36px;text-align:center}
.trash-item .info{flex:1;min-width:0}
.trash-item .info .name{font-size:14px;font-weight:600;word-break:break-all}
.trash-item .info .meta{font-size:12px;color:var(--muted);margin-top:2px}
.trash-item .actions{display:flex;gap:6px}

/* ─── Admin ─── */
.admin-table{width:100%;border-collapse:collapse;background:var(--card);border-radius:12px;overflow:hidden;box-shadow:var(--shadow)}
.admin-table th{background:var(--hover);padding:12px 14px;font-size:13px;font-weight:600;text-align:left;color:var(--text)}
.admin-table td{padding:12px 14px;font-size:13px;border-bottom:1px solid var(--border)}
.admin-table tr:last-child td{border-bottom:0}
.admin-table code{font-size:12px;background:var(--input-bg);padding:2px 6px;border-radius:4px;word-break:break-all}

/* ─── Danger Zone ─── */
.btn-del{background:#dc2626;color:#fff;padding:10px 20px;border:0;border-radius:10px;font-size:14px;font-weight:500;cursor:pointer;transition:all .15s}
.btn-del:hover{filter:brightness(1.1)}

/* ─── Loading ─── */
.loading{text-align:center;padding:60px 20px;color:var(--muted)}
.spinner{width:36px;height:36px;border:4px solid var(--border);border-top-color:var(--accent2);border-radius:50%;animation:spin .7s linear infinite;margin:0 auto 14px}
@keyframes spin{to{transform:rotate(360deg)}}
.error-box{background:#fef2f2;border:1px solid #fecaca;border-radius:12px;padding:24px;text-align:center;color:#dc2626;font-size:14px}
[data-theme="dark"] .error-box{background:#3b1a1a;border-color:#4f1f1f;color:#f87171}
.loading-overlay{position:fixed;top:0;left:0;width:100%;height:100%;background:rgba(0,0,0,.3);z-index:200;display:flex;align-items:center;justify-content:center;backdrop-filter:blur(2px)}
.loading-overlay .spinner{width:44px;height:44px;border-width:4px}

/* ─── Responsive ─── */
@media(max-width:768px){
  .page.active.auth-page{background:linear-gradient(135deg,#667eea,#764ba2);padding:16px}
  .auth-card{padding:28px 20px;border-radius:12px;margin:0}
  .auth-card h1{font-size:24px}
  .container{padding:16px}
  nav{padding:0 14px;height:52px}
  .nav-brand{font-size:17px}
  .nav-user{font-size:13px;gap:6px}
  .nav-user span{display:none}
  .dashboard-header{flex-wrap:wrap;gap:10px}
  .dashboard-header h2{font-size:18px}
  .folder-grid{grid-template-columns:repeat(auto-fill,minmax(160px,1fr));gap:12px}
  .folder-card{padding:16px}
  .folder-card .icon{font-size:28px}
  .folder-card .name{font-size:14px}
  .folder-actions-bar{flex-direction:column;align-items:flex-start;gap:8px}
  .sort-group,.filter-group{flex-wrap:wrap}
  .upload-area{padding:24px 16px}
  .upload-label::before{font-size:28px}
  .upload-progress{flex-direction:column;gap:6px;padding:12px 14px}
  .upload-progress span{min-width:0;font-size:12px}
  .batch-bar{flex-wrap:wrap;gap:8px;padding:10px 14px}
  .batch-bar span{font-size:13px;width:100%}
  .file-grid{grid-template-columns:repeat(auto-fill,minmax(150px,1fr));gap:12px}
  .file-thumb{height:120px;font-size:30px}
  .file-card .info{padding:10px}
  .file-card .info .name{font-size:13px}
  .file-actions{gap:2px;flex-wrap:wrap}
  .btn-icon{width:26px;height:26px;font-size:12px}
  .btn-file{font-size:11px;padding:4px 8px;height:26px}
  .search-bar{flex-direction:column}
  .search-bar .btn-primary{width:100%}
  .modal-content{padding:20px;max-width:96%}
  .modal-preview-content{padding:14px}
  .preview-img{max-height:50vh}
  #preview-pdf{height:50vh}
  .account-card{padding:18px}
  .account-card h3{font-size:15px}
  .account-row{padding:8px 0}
  .account-label,.account-value{font-size:13px}
  .share-body{padding:20px 16px}
  .share-body h1{font-size:24px}
  .share-file-card img{height:140px}
  .loading-overlay .spinner{width:36px;height:36px}
  .breadcrumb{font-size:13px}
}

@media(max-width:400px){
  .auth-card{padding:20px 16px}
  .auth-card h1{font-size:20px}
  .container{padding:12px}
  .folder-grid{grid-template-columns:1fr 1fr;gap:10px}
  .file-grid{grid-template-columns:1fr 1fr;gap:10px}
  .folder-card{padding:12px}
  .folder-card .icon{font-size:24px}
  .file-thumb{height:100px;font-size:24px}
  .dashboard-header{flex-direction:column;align-items:stretch}
  .dashboard-header .btn-primary{width:100%;text-align:center}
  nav{padding:0 10px;height:48px}
  .nav-brand{font-size:15px}
  .nav-user{font-size:12px;gap:4px}
  .upload-area{padding:16px 12px}
  .modal-content{padding:16px}
}