/* ===== RESET & BASE ===== */
*{margin:0;padding:0;box-sizing:border-box}
:root{
  --bg:#0b0f19;--bg2:#111827;--bg3:#1a2236;--bg4:#243049;
  --text:#e2e8f0;--text2:#94a3b8;--text3:#64748b;
  --accent:#3b82f6;--accent2:#60a5fa;--accent3:#2563eb;
  --green:#22c55e;--red:#ef4444;--orange:#f59e0b;--purple:#a855f7;
  --border:rgba(148,163,184,0.12);--glass:rgba(255,255,255,0.04);
  --radius:12px;--radius-sm:8px;
  --shadow:0 4px 24px rgba(0,0,0,0.3);
  --font:'Segoe UI','PingFang SC','Microsoft YaHei','Helvetica Neue',sans-serif;
}
html{font-size:16px;scroll-behavior:smooth}
body{font-family:var(--font);background:var(--bg);color:var(--text);min-height:100vh;line-height:1.6;-webkit-font-smoothing:antialiased}
a{color:var(--accent2);text-decoration:none;transition:color 0.3s}
a:hover{color:var(--accent)}
.container{max-width:1100px;margin:0 auto;padding:0 20px}

/* ===== HEADER ===== */
.site-header{position:sticky;top:0;z-index:100;background:rgba(11,15,25,0.85);backdrop-filter:blur(20px);-webkit-backdrop-filter:blur(20px);border-bottom:1px solid var(--border)}
.header-inner{display:flex;align-items:center;justify-content:space-between;height:60px}
.logo{display:flex;align-items:center;gap:8px;font-size:1.2rem;font-weight:600;color:var(--text);letter-spacing:0.02em}
.logo-icon{color:var(--accent);font-size:1.4rem}
.main-nav{display:flex;align-items:center;gap:6px}
.nav-link{padding:7px 16px;border-radius:var(--radius-sm);color:var(--text2);font-size:0.88rem;font-weight:400;transition:all 0.3s}
.nav-link:hover,.nav-link.active{color:var(--text);background:var(--glass)}
.nav-link.active{color:var(--accent2)}
.nav-register{background:rgba(59,130,246,0.12);color:var(--accent2);border:1px solid rgba(59,130,246,0.2)}
.nav-register:hover{background:rgba(59,130,246,0.2)}
.nav-user{padding:6px 12px;color:var(--accent2);font-size:0.85rem;font-weight:500}
.nav-logout{color:var(--text3);font-size:0.82rem}
.mobile-menu-btn{display:none;background:none;border:none;color:var(--text);font-size:1.4rem;cursor:pointer}

/* ===== MAIN CONTENT ===== */
.main-content{padding:32px 20px;min-height:calc(100vh - 140px)}

/* ===== HERO / HOME ===== */
.home-hero{text-align:center;padding:48px 0 36px}
.home-hero h1{font-size:2.2rem;font-weight:600;margin-bottom:10px;background:linear-gradient(135deg,var(--accent2),var(--purple));-webkit-background-clip:text;-webkit-text-fill-color:transparent;background-clip:text}
.home-hero p{color:var(--text2);font-size:1rem;max-width:500px;margin:0 auto}
.search-bar{display:flex;gap:10px;max-width:560px;margin:28px auto 0;position:relative}
.search-bar input{flex:1;padding:12px 18px;background:var(--bg3);border:1px solid var(--border);border-radius:var(--radius);color:var(--text);font-size:0.95rem;outline:none;transition:border-color 0.3s}
.search-bar input:focus{border-color:var(--accent)}
.search-bar input::placeholder{color:var(--text3)}
.search-bar button{padding:12px 24px;background:var(--accent3);color:#fff;border:none;border-radius:var(--radius);font-size:0.9rem;cursor:pointer;transition:background 0.3s;white-space:nowrap}
.search-bar button:hover{background:var(--accent)}

/* ===== FILE GRID ===== */
.section-title{font-size:1.15rem;font-weight:500;margin:32px 0 18px;color:var(--text);display:flex;align-items:center;gap:10px}
.section-title .count{font-size:0.82rem;color:var(--text3);font-weight:400}
.file-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(300px,1fr));gap:16px;margin-bottom:32px}
.file-card{background:var(--bg2);border:1px solid var(--border);border-radius:var(--radius);padding:20px;transition:all 0.3s;cursor:pointer;position:relative;overflow:hidden}
.file-card:hover{border-color:rgba(59,130,246,0.3);transform:translateY(-2px);box-shadow:var(--shadow)}
.file-card-header{display:flex;align-items:flex-start;gap:14px;margin-bottom:12px}
.file-icon{font-size:2rem;flex-shrink:0;width:48px;height:48px;display:flex;align-items:center;justify-content:center;background:var(--glass);border-radius:var(--radius-sm)}
.file-info{flex:1;min-width:0}
.file-name{font-size:0.95rem;font-weight:500;color:var(--text);word-break:break-word;line-height:1.4;margin-bottom:4px}
.file-meta{font-size:0.78rem;color:var(--text3);display:flex;gap:12px;flex-wrap:wrap}
.file-desc{font-size:0.84rem;color:var(--text2);margin-bottom:14px;line-height:1.6;display:-webkit-box;-webkit-line-clamp:2;-webkit-box-orient:vertical;overflow:hidden}
.file-card-footer{display:flex;align-items:center;justify-content:space-between;padding-top:12px;border-top:1px solid var(--border)}
.file-uploader{font-size:0.78rem;color:var(--text3)}
.file-downloads{font-size:0.78rem;color:var(--text3)}
.btn-download{padding:7px 18px;background:rgba(34,197,94,0.12);color:var(--green);border:1px solid rgba(34,197,94,0.25);border-radius:var(--radius-sm);font-size:0.82rem;cursor:pointer;transition:all 0.3s;text-decoration:none}
.btn-download:hover{background:rgba(34,197,94,0.2);border-color:rgba(34,197,94,0.4)}

/* ===== AUTH PAGES ===== */
.auth-container{max-width:420px;margin:60px auto}
.auth-card{background:var(--bg2);border:1px solid var(--border);border-radius:var(--radius);padding:36px}
.auth-card h2{font-size:1.4rem;font-weight:500;margin-bottom:6px}
.auth-card .subtitle{color:var(--text3);font-size:0.88rem;margin-bottom:28px}
.form-group{margin-bottom:18px}
.form-group label{display:block;font-size:0.84rem;color:var(--text2);margin-bottom:6px;font-weight:400}
.form-group input,.form-group textarea,.form-group select{width:100%;padding:11px 16px;background:var(--bg3);border:1px solid var(--border);border-radius:var(--radius-sm);color:var(--text);font-size:0.9rem;font-family:var(--font);outline:none;transition:border-color 0.3s}
.form-group input:focus,.form-group textarea:focus{border-color:var(--accent)}
.form-group textarea{resize:vertical;min-height:80px}
.form-group .hint{font-size:0.76rem;color:var(--text3);margin-top:4px}
.btn{padding:11px 24px;border:none;border-radius:var(--radius-sm);cursor:pointer;font-size:0.9rem;font-weight:500;font-family:var(--font);transition:all 0.3s;display:inline-flex;align-items:center;gap:6px}
.btn-primary{background:var(--accent3);color:#fff;width:100%}
.btn-primary:hover{background:var(--accent)}
.btn-sm{padding:7px 16px;font-size:0.82rem}
.btn-green{background:rgba(34,197,94,0.15);color:var(--green);border:1px solid rgba(34,197,94,0.25)}
.btn-green:hover{background:rgba(34,197,94,0.25)}
.btn-red{background:rgba(239,68,68,0.1);color:var(--red);border:1px solid rgba(239,68,68,0.2)}
.btn-red:hover{background:rgba(239,68,68,0.2)}
.btn-outline{background:transparent;color:var(--text2);border:1px solid var(--border)}
.btn-outline:hover{border-color:var(--accent);color:var(--accent2)}
.auth-footer{text-align:center;margin-top:18px;font-size:0.85rem;color:var(--text3)}
.auth-footer a{color:var(--accent2)}
.msg{padding:12px 16px;border-radius:var(--radius-sm);margin-bottom:16px;font-size:0.88rem}
.msg-ok{background:rgba(34,197,94,0.1);color:var(--green);border:1px solid rgba(34,197,94,0.2)}
.msg-err{background:rgba(239,68,68,0.1);color:var(--red);border:1px solid rgba(239,68,68,0.2)}
.msg-warn{background:rgba(245,158,11,0.1);color:var(--orange);border:1px solid rgba(245,158,11,0.2)}

/* ===== DASHBOARD ===== */
.dash-header{display:flex;align-items:center;justify-content:space-between;margin-bottom:24px;flex-wrap:wrap;gap:12px}
.dash-header h2{font-size:1.4rem;font-weight:500}
.upload-zone{background:var(--bg2);border:2px dashed var(--border);border-radius:var(--radius);padding:40px;text-align:center;margin-bottom:28px;transition:border-color 0.3s;cursor:pointer}
.upload-zone:hover,.upload-zone.dragover{border-color:var(--accent);background:rgba(59,130,246,0.04)}
.upload-zone .upload-icon{font-size:2.5rem;margin-bottom:10px}
.upload-zone p{color:var(--text2);font-size:0.92rem;margin-bottom:6px}
.upload-zone .upload-hint{color:var(--text3);font-size:0.8rem}
.upload-progress{display:none;margin-top:16px}
.upload-progress .progress-bar{height:6px;background:var(--bg4);border-radius:3px;overflow:hidden}
.upload-progress .progress-fill{height:100%;background:var(--accent);border-radius:3px;transition:width 0.3s;width:0}
.upload-progress .progress-text{font-size:0.82rem;color:var(--text2);margin-top:6px}
.my-files{margin-top:8px}
.file-table{width:100%;border-collapse:collapse}
.file-table th{text-align:left;padding:10px 14px;font-size:0.78rem;color:var(--text3);font-weight:500;text-transform:uppercase;letter-spacing:0.05em;border-bottom:1px solid var(--border)}
.file-table td{padding:12px 14px;border-bottom:1px solid var(--border);font-size:0.88rem;color:var(--text2);vertical-align:middle}
.file-table tr:hover td{background:var(--glass)}
.file-table .fname{color:var(--text);font-weight:400;word-break:break-word;max-width:260px}
.file-table .actions{display:flex;gap:6px;flex-wrap:wrap}
.copy-link{font-size:0.78rem;color:var(--accent2);cursor:pointer;padding:4px 10px;border:1px solid rgba(59,130,246,0.2);border-radius:6px;background:rgba(59,130,246,0.08);transition:all 0.3s}
.copy-link:hover{background:rgba(59,130,246,0.15)}

/* ===== FILE DETAIL ===== */
.file-detail{max-width:640px;margin:40px auto;background:var(--bg2);border:1px solid var(--border);border-radius:var(--radius);padding:36px}
.file-detail-icon{font-size:3.5rem;text-align:center;margin-bottom:16px}
.file-detail h2{text-align:center;font-size:1.3rem;font-weight:500;margin-bottom:8px;word-break:break-word}
.file-detail-meta{text-align:center;color:var(--text3);font-size:0.85rem;margin-bottom:24px;display:flex;justify-content:center;gap:16px;flex-wrap:wrap}
.file-detail-desc{color:var(--text2);font-size:0.92rem;line-height:1.8;margin-bottom:28px;padding:16px;background:var(--glass);border-radius:var(--radius-sm);border:1px solid var(--border)}
.file-detail-actions{text-align:center;display:flex;gap:12px;justify-content:center;flex-wrap:wrap}
.file-detail-actions .btn-download{padding:12px 32px;font-size:0.95rem}

/* ===== ADMIN ===== */
.admin-tabs{display:flex;gap:6px;margin-bottom:24px;flex-wrap:wrap}
.admin-tab{padding:8px 20px;border-radius:var(--radius-sm);font-size:0.88rem;color:var(--text2);cursor:pointer;border:1px solid var(--border);background:transparent;transition:all 0.3s;font-family:var(--font)}
.admin-tab:hover,.admin-tab.active{color:var(--accent2);border-color:rgba(59,130,246,0.3);background:rgba(59,130,246,0.08)}
.admin-section{display:none}
.admin-section.active{display:block}
.stat-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(200px,1fr));gap:14px;margin-bottom:28px}
.stat-card{background:var(--bg2);border:1px solid var(--border);border-radius:var(--radius);padding:20px;text-align:center}
.stat-card .stat-num{font-size:1.8rem;font-weight:600;color:var(--accent2)}
.stat-card .stat-label{font-size:0.82rem;color:var(--text3);margin-top:4px}
.admin-table{width:100%;border-collapse:collapse}
.admin-table th{text-align:left;padding:10px 12px;font-size:0.78rem;color:var(--text3);font-weight:500;text-transform:uppercase;letter-spacing:0.04em;border-bottom:1px solid var(--border)}
.admin-table td{padding:10px 12px;border-bottom:1px solid var(--border);font-size:0.86rem;color:var(--text2)}
.admin-table tr:hover td{background:var(--glass)}
.badge{display:inline-block;padding:3px 10px;border-radius:12px;font-size:0.72rem;font-weight:500}
.badge-admin{background:rgba(168,85,247,0.15);color:var(--purple)}
.badge-active{background:rgba(34,197,94,0.12);color:var(--green)}
.badge-pending{background:rgba(245,158,11,0.12);color:var(--orange)}
.toggle-switch{position:relative;width:44px;height:24px;display:inline-block}
.toggle-switch input{opacity:0;width:0;height:0}
.toggle-slider{position:absolute;inset:0;background:var(--bg4);border-radius:12px;cursor:pointer;transition:0.3s}
.toggle-slider:before{content:"";position:absolute;width:18px;height:18px;left:3px;bottom:3px;background:#fff;border-radius:50%;transition:0.3s}
.toggle-switch input:checked+.toggle-slider{background:var(--accent3)}
.toggle-switch input:checked+.toggle-slider:before{transform:translateX(20px)}

/* ===== EMPTY STATE ===== */
.empty-state{text-align:center;padding:60px 20px;color:var(--text3)}
.empty-state .empty-icon{font-size:3rem;margin-bottom:12px;opacity:0.5}
.empty-state p{font-size:0.95rem}

/* ===== FOOTER ===== */
.site-footer{border-top:1px solid var(--border);padding:20px;text-align:center;color:var(--text3);font-size:0.82rem}

/* ===== TOAST ===== */
.toast{position:fixed;bottom:24px;right:24px;padding:14px 22px;background:var(--bg3);border:1px solid var(--border);border-radius:var(--radius-sm);color:var(--text);font-size:0.88rem;z-index:9999;transform:translateY(100px);opacity:0;transition:all 0.4s;box-shadow:var(--shadow)}
.toast.show{transform:translateY(0);opacity:1}
.toast.success{border-color:rgba(34,197,94,0.3)}
.toast.error{border-color:rgba(239,68,68,0.3)}

/* ===== PAGINATION ===== */
.pagination{display:flex;justify-content:center;gap:6px;margin:24px 0}
.pagination a,.pagination span{padding:8px 14px;border-radius:var(--radius-sm);font-size:0.85rem;color:var(--text2);border:1px solid var(--border);transition:all 0.3s}
.pagination a:hover{border-color:var(--accent);color:var(--accent2)}
.pagination .current{background:var(--accent3);color:#fff;border-color:var(--accent3)}

/* ===== RESPONSIVE ===== */
@media(max-width:768px){
  .mobile-menu-btn{display:block}
  .main-nav{display:none;position:absolute;top:60px;left:0;right:0;background:var(--bg2);border-bottom:1px solid var(--border);padding:12px;flex-direction:column;gap:4px}
  .main-nav.open{display:flex}
  .file-grid{grid-template-columns:1fr}
  .home-hero h1{font-size:1.6rem}
  .stat-grid{grid-template-columns:repeat(2,1fr)}
  .file-table{font-size:0.82rem}
  .file-table th:nth-child(3),.file-table td:nth-child(3){display:none}
  .dash-header{flex-direction:column;align-items:flex-start}
}