:root{
  --c-bg:#F6F7FB;
  --c-surface:#FFFFFF;
  --c-surface-2:#F1F3F9;
  --c-border:#E4E7EF;
  --c-border-strong:#CBD1DE;
  --c-text:#0F172A;
  --c-text-2:#475569;
  --c-text-3:#8592A6;
  --c-primary:#4F46E5;
  --c-primary-weak:#EEF0FE;
  --c-primary-hover:#4338CA;
  --c-danger:#DC2626;
  --c-danger-weak:#FEE2E2;
  --c-success:#059669;
  --c-warn:#D97706;
  --r-sm:6px; --r-md:10px; --r-lg:14px; --r-xl:20px;
  --shadow-1:0 1px 2px rgba(15,23,42,.04),0 1px 3px rgba(15,23,42,.06);
  --shadow-2:0 6px 20px rgba(15,23,42,.08),0 2px 6px rgba(15,23,42,.05);
  --shadow-3:0 20px 40px rgba(15,23,42,.15);
  --f-sans:-apple-system,BlinkMacSystemFont,"PingFang SC","Microsoft YaHei","Segoe UI",Roboto,Helvetica,Arial,sans-serif;
  --f-mono:ui-monospace,SFMono-Regular,Menlo,Consolas,monospace;
}
*{box-sizing:border-box}
html,body{margin:0;padding:0}
body{font-family:var(--f-sans);background:var(--c-bg);color:var(--c-text);font-size:14px;line-height:1.6;min-height:100vh;-webkit-font-smoothing:antialiased}
button{font-family:inherit;cursor:pointer;border:none;background:none;color:inherit}
input,textarea{font-family:inherit;color:inherit}
.hidden{display:none !important}

/* Gate */
.gate{position:fixed;inset:0;display:flex;align-items:center;justify-content:center;background:linear-gradient(160deg,#EEF0FE 0%,#F6F7FB 60%,#FFF 100%);z-index:100;padding:24px}
.gate-card{background:var(--c-surface);border:1px solid var(--c-border);border-radius:var(--r-xl);padding:36px 32px 28px;width:100%;max-width:400px;box-shadow:var(--shadow-2)}
.gate-logo{width:56px;height:56px;border-radius:16px;background:linear-gradient(135deg,var(--c-primary) 0%,#7C3AED 100%);display:flex;align-items:center;justify-content:center;margin-bottom:20px;box-shadow:0 8px 20px rgba(79,70,229,.28)}
.gate-logo svg{width:28px;height:28px;color:#fff}
.gate h1{font-size:22px;font-weight:600;margin:0 0 6px}
.gate p{color:var(--c-text-2);margin:0 0 24px;font-size:13px}
.gate .field{margin-bottom:14px}
.gate label{display:block;font-size:12px;color:var(--c-text-2);margin-bottom:6px;font-weight:500}
.gate input{width:100%;padding:11px 14px;border:1px solid var(--c-border);border-radius:var(--r-md);background:var(--c-surface);font-size:14px;transition:border-color .15s,box-shadow .15s}
.gate input:focus{outline:none;border-color:var(--c-primary);box-shadow:0 0 0 3px var(--c-primary-weak)}
.err{color:var(--c-danger);font-size:12px;margin-top:8px;min-height:18px}

.btn{display:inline-flex;align-items:center;justify-content:center;gap:6px;padding:9px 14px;border-radius:var(--r-md);font-size:13px;font-weight:500;transition:background .15s,color .15s,border-color .15s,transform .05s;border:1px solid transparent;white-space:nowrap}
.btn:active{transform:translateY(1px)}
.btn svg{width:14px;height:14px}
.btn-primary{background:var(--c-primary);color:#fff}
.btn-primary:hover{background:var(--c-primary-hover)}
.btn-block{width:100%;padding:11px 16px;font-size:14px}
.btn-ghost{background:transparent;color:var(--c-text-2);border:1px solid var(--c-border)}
.btn-ghost:hover{background:var(--c-surface-2);color:var(--c-text)}
.btn-danger{background:var(--c-danger);color:#fff}
.btn-danger:hover{background:#B91C1C}
.btn-text{padding:6px 10px;color:var(--c-text-2);font-size:12px;border-radius:var(--r-sm);background:none;border:none}
.btn-text:hover{background:var(--c-surface-2);color:var(--c-text)}
.btn-text.danger:hover{background:var(--c-danger-weak);color:var(--c-danger)}

/* App shell */
.app{max-width:960px;margin:0 auto;padding:32px 20px 80px}
.header{display:flex;align-items:flex-start;justify-content:space-between;margin-bottom:28px;gap:16px}
.brand{display:flex;align-items:center;gap:12px}
.brand-icon{width:44px;height:44px;border-radius:12px;background:linear-gradient(135deg,var(--c-primary) 0%,#7C3AED 100%);display:flex;align-items:center;justify-content:center;box-shadow:0 6px 14px rgba(79,70,229,.22)}
.brand-icon svg{width:22px;height:22px;color:#fff}
.brand-text h1{margin:0;font-size:22px;font-weight:600;letter-spacing:-0.01em}
.brand-text p{margin:2px 0 0;color:var(--c-text-2);font-size:13px}
.actions{display:flex;gap:8px}
.icon-btn{width:36px;height:36px;border-radius:var(--r-md);display:inline-flex;align-items:center;justify-content:center;background:var(--c-surface);border:1px solid var(--c-border);color:var(--c-text-2);transition:all .15s;cursor:pointer}
.icon-btn:hover{color:var(--c-text);border-color:var(--c-border-strong);background:var(--c-surface-2)}
.icon-btn svg{width:18px;height:18px}

/* Zones */
.zone{background:var(--c-surface);border:1px solid var(--c-border);border-radius:var(--r-lg);padding:20px;margin-bottom:14px;box-shadow:var(--shadow-1)}
.zone-title{display:flex;align-items:center;gap:6px;font-size:12px;font-weight:600;color:var(--c-text-2);margin-bottom:10px;text-transform:uppercase;letter-spacing:.05em}
.zone-title svg{width:14px;height:14px}
.text-input{width:100%;min-height:88px;padding:12px 14px;border:1px solid var(--c-border);border-radius:var(--r-md);resize:vertical;font-size:14px;line-height:1.55;background:var(--c-surface);transition:border-color .15s,box-shadow .15s;display:block}
.text-input:focus{outline:none;border-color:var(--c-primary);box-shadow:0 0 0 3px var(--c-primary-weak)}
.text-input::placeholder{color:var(--c-text-3)}
.text-row{display:flex;justify-content:space-between;align-items:center;margin-top:10px;gap:12px;flex-wrap:wrap}
.hint{font-size:12px;color:var(--c-text-3)}
.hint kbd{display:inline-block;padding:1px 6px;border:1px solid var(--c-border);border-radius:4px;background:var(--c-surface-2);font-family:var(--f-mono);font-size:11px;color:var(--c-text-2)}

.dropzone{border:2px dashed var(--c-border-strong);border-radius:var(--r-lg);background:var(--c-surface);padding:28px 20px;text-align:center;transition:all .18s;cursor:pointer;margin-bottom:24px}
.dropzone:hover{border-color:var(--c-primary);background:var(--c-primary-weak)}
.dropzone.drag-over{border-color:var(--c-primary);background:var(--c-primary-weak);transform:scale(1.005)}
.dropzone-icon{width:44px;height:44px;border-radius:12px;background:var(--c-primary-weak);color:var(--c-primary);display:inline-flex;align-items:center;justify-content:center;margin-bottom:12px}
.dropzone-icon svg{width:22px;height:22px}
.dropzone-title{font-size:15px;font-weight:500;color:var(--c-text);margin-bottom:4px}
.dropzone-sub{font-size:12px;color:var(--c-text-3);margin-bottom:14px}
.format-chips{display:flex;flex-wrap:wrap;gap:6px;justify-content:center}
.chip{font-size:11px;padding:3px 10px;border-radius:999px;background:var(--c-surface-2);color:var(--c-text-2);font-weight:500;border:1px solid var(--c-border)}

/* List */
.list-header{display:flex;align-items:center;justify-content:space-between;margin:8px 0 14px}
.list-header h2{font-size:16px;font-weight:600;margin:0}
.list-count{font-size:12px;color:var(--c-text-3);background:var(--c-surface);border:1px solid var(--c-border);padding:2px 10px;border-radius:999px}
.items{display:flex;flex-direction:column;gap:10px}
.item{background:var(--c-surface);border:1px solid var(--c-border);border-radius:var(--r-lg);padding:12px 14px;display:flex;gap:12px;align-items:center;transition:box-shadow .15s,border-color .15s}
.item:hover{box-shadow:var(--shadow-2);border-color:var(--c-border-strong)}
.item-icon{flex-shrink:0;width:40px;height:40px;border-radius:10px;display:flex;align-items:center;justify-content:center}
.item-icon svg{width:20px;height:20px}
.icon-text{background:#EEF0FE;color:#4F46E5}
.icon-image{background:#FEF3C7;color:#B45309}
.icon-pdf{background:#FEE2E2;color:#DC2626}
.icon-doc{background:#DBEAFE;color:#2563EB}
.icon-xls{background:#D1FAE5;color:#059669}
.icon-ppt{background:#FED7AA;color:#EA580C}
.icon-video{background:#F3E8FF;color:#9333EA}
.icon-audio{background:#CFFAFE;color:#0891B2}
.icon-zip{background:#E5E7EB;color:#4B5563}
.icon-file{background:#F1F5F9;color:#64748B}

.item-thumb{flex-shrink:0;width:44px;height:44px;border-radius:10px;object-fit:cover;background:var(--c-surface-2);border:1px solid var(--c-border);cursor:pointer}
.item-main{flex:1;min-width:0}
.item-name{font-size:14px;font-weight:500;color:var(--c-text);white-space:nowrap;overflow:hidden;text-overflow:ellipsis;margin-bottom:2px}
.item-preview{font-size:12px;color:var(--c-text-2);white-space:nowrap;overflow:hidden;text-overflow:ellipsis;line-height:1.4;margin-bottom:4px;font-family:var(--f-mono)}
.item-meta{display:flex;align-items:center;gap:8px;font-size:11px;color:var(--c-text-3);flex-wrap:wrap}
.item-meta .dot{width:3px;height:3px;background:var(--c-text-3);border-radius:50%;opacity:.6}
.item-expire.warn{color:var(--c-warn)}
.item-actions{flex-shrink:0;display:flex;gap:2px;align-items:center}
.item-actions button{width:32px;height:32px;border-radius:8px;color:var(--c-text-3);display:inline-flex;align-items:center;justify-content:center;transition:all .12s;cursor:pointer;background:none;border:none}
.item-actions button:hover{background:var(--c-surface-2);color:var(--c-text)}
.item-actions button.danger:hover{background:var(--c-danger-weak);color:var(--c-danger)}
.item-actions svg{width:16px;height:16px}

.empty{text-align:center;padding:48px 20px;color:var(--c-text-3);background:var(--c-surface);border:1px dashed var(--c-border);border-radius:var(--r-lg)}
.empty svg{width:44px;height:44px;color:var(--c-border-strong);margin-bottom:10px}
.empty p{margin:0;font-size:14px;color:var(--c-text-2);font-weight:500}
.empty span{font-size:12px;color:var(--c-text-3)}

/* Modals */
.modal{position:fixed;inset:0;z-index:200;display:flex;align-items:center;justify-content:center;padding:20px;animation:fadeIn .15s ease}
.modal-mask{position:absolute;inset:0;background:rgba(15,23,42,.42);backdrop-filter:blur(4px)}
.modal-card{position:relative;background:var(--c-surface);border-radius:var(--r-xl);width:100%;max-width:440px;box-shadow:var(--shadow-3);max-height:90vh;display:flex;flex-direction:column;animation:slideUp .2s ease}
.modal-card-lg{max-width:760px}
.modal-header{display:flex;align-items:center;justify-content:space-between;padding:18px 20px 12px;border-bottom:1px solid var(--c-border)}
.modal-header h3{margin:0;font-size:16px;font-weight:600}
.modal-body{padding:16px 20px 20px;overflow:auto}
.modal-body .field{margin-bottom:12px}
.modal-body label{display:block;font-size:12px;color:var(--c-text-2);margin-bottom:6px;font-weight:500}
.modal-body input{width:100%;padding:10px 12px;border:1px solid var(--c-border);border-radius:var(--r-md);font-size:14px;background:var(--c-surface)}
.modal-body input:focus{outline:none;border-color:var(--c-primary);box-shadow:0 0 0 3px var(--c-primary-weak)}

.setting-row{display:flex;align-items:center;justify-content:space-between;padding:14px 0;border-bottom:1px solid var(--c-border);gap:12px}
.setting-row:last-child{border-bottom:none;padding-bottom:0}
.setting-row:first-child{padding-top:0}
.setting-label{font-size:14px;font-weight:500;color:var(--c-text)}
.setting-label.setting-danger{color:var(--c-danger)}
.setting-desc{font-size:12px;color:var(--c-text-3);margin-top:2px}
.segmented{display:inline-flex;background:var(--c-surface-2);border:1px solid var(--c-border);border-radius:var(--r-md);padding:2px;gap:2px}
.segmented button{padding:6px 10px;font-size:12px;font-weight:500;color:var(--c-text-2);border-radius:6px;transition:all .12s;cursor:pointer;border:none;background:none}
.segmented button:hover{color:var(--c-text)}
.segmented button.active{background:var(--c-surface);color:var(--c-primary);box-shadow:0 1px 2px rgba(15,23,42,.06)}

.pv-img{max-width:100%;max-height:70vh;display:block;margin:0 auto;border-radius:var(--r-md)}
.pv-text{white-space:pre-wrap;word-break:break-word;font-family:var(--f-mono);font-size:13px;line-height:1.6;background:var(--c-surface-2);padding:14px;border-radius:var(--r-md);max-height:70vh;overflow:auto;margin:0;color:var(--c-text)}
.pv-video{max-width:100%;max-height:70vh;display:block;margin:0 auto;border-radius:var(--r-md);background:#000}
.pv-audio{width:100%;margin:20px 0}
.pv-fallback{padding:24px;text-align:center;color:var(--c-text-2)}
.pv-actions{display:flex;justify-content:flex-end;gap:8px;margin-top:14px;padding-top:14px;border-top:1px solid var(--c-border)}

/* Toast */
.toast{position:fixed;bottom:32px;left:50%;transform:translateX(-50%) translateY(10px);background:#0F172A;color:#fff;padding:10px 18px;border-radius:999px;font-size:13px;box-shadow:var(--shadow-3);z-index:300;opacity:0;transition:opacity .2s,transform .2s;pointer-events:none;max-width:calc(100vw - 40px)}
.toast.show{opacity:1;transform:translateX(-50%) translateY(0)}
.toast.err{background:#B91C1C}
.toast.ok{background:#047857}

@keyframes fadeIn{from{opacity:0}to{opacity:1}}
@keyframes slideUp{from{opacity:0;transform:translateY(12px) scale(.98)}to{opacity:1;transform:translateY(0) scale(1)}}

/* Global drag highlight */
body.dragging{position:relative}
body.dragging::before{content:"松开鼠标即可上传";position:fixed;inset:0;background:rgba(79,70,229,.08);border:3px dashed var(--c-primary);z-index:150;pointer-events:none;display:flex;align-items:center;justify-content:center;color:var(--c-primary);font-size:24px;font-weight:600;letter-spacing:.05em}

/* Responsive */
@media (max-width:640px){
  .app{padding:20px 14px 60px}
  .header{margin-bottom:20px}
  .brand-text h1{font-size:18px}
  .brand-text p{font-size:12px}
  .item{flex-wrap:wrap;padding:12px}
  .item-actions{width:100%;justify-content:flex-end;margin-top:4px}
  .segmented button{padding:5px 8px;font-size:11px}
  .setting-row{flex-direction:column;align-items:flex-start;gap:10px}
  .dropzone-title{font-size:14px}
}