:root{--ink:#1a1a1a;--muted:#999;--line:#e8e8e8;--accent:#333;--hover:#000;--bg:#fff;--soft:#f7f7f7}
*[hidden]{display:none!important}
.visually-hidden{position:absolute;width:1px;height:1px;margin:-1px;padding:0;overflow:hidden;clip:rect(0,0,0,0);border:0;opacity:0;pointer-events:none}
*{box-sizing:border-box}
body{margin:0;background:var(--bg);color:var(--ink);font-family:-apple-system,BlinkMacSystemFont,"Segoe UI","Microsoft YaHei",sans-serif;min-height:100vh;-webkit-font-smoothing:antialiased}

/* ===== Shell ===== */
.shell{max-width:420px;margin:0 auto;padding:60px 20px 40px}

/* ===== Hero ===== */
.hero{text-align:center;margin-bottom:36px}
.hero h1{font-size:24px;font-weight:700;margin:0 0 6px;letter-spacing:-.02em}
.hero p{font-size:14px;color:var(--muted);margin:0}

/* ===== Workspace ===== */
.workspace{margin-bottom:32px}

/* Dropzone */
.dropzone{border:2px dashed var(--line);border-radius:12px;padding:40px 20px;text-align:center;transition:.2s;cursor:pointer}
.dropzone.is-over{border-color:var(--accent);background:var(--soft)}
.dropzone-trigger{display:flex;flex-direction:column;align-items:center;gap:8px;cursor:pointer}
.drop-icon{font-size:28px;color:var(--muted);line-height:1}
.drop-text{font-size:14px;color:var(--ink);font-weight:500}

/* File panel */
.file-panel{display:flex;align-items:center;gap:10px;background:var(--soft);border-radius:8px;padding:12px 14px;margin-top:12px}
.file-meta{flex:1;display:flex;flex-direction:column;gap:2px;min-width:0}
.file-meta strong{font-size:13px;overflow:hidden;text-overflow:ellipsis;white-space:nowrap}
.file-meta span{color:var(--muted);font-size:11px}
.icon-btn{border:0;background:transparent;font-size:18px;color:var(--muted);cursor:pointer;flex-shrink:0;padding:0;width:28px;height:28px;display:grid;place-items:center;border-radius:50%;transition:.15s}
.icon-btn:hover{background:var(--line);color:var(--ink)}

/* Controls */
.controls{display:flex;gap:8px;margin-top:12px}
.select-control{flex:1;border:1px solid var(--line);border-radius:8px;padding:0 12px;display:flex;align-items:center;height:44px}
.select-control select{border:0;background:transparent;padding:0;outline:0;cursor:pointer;font-size:14px;font-weight:500;color:var(--ink);width:100%}

/* Convert button */
.convert-btn{flex-shrink:0;border:0;padding:0 24px;height:44px;background:var(--accent);color:#fff;border-radius:8px;font:600 14px inherit;cursor:pointer;transition:.2s}
.convert-btn:disabled{background:var(--line);color:var(--muted);cursor:not-allowed}
.convert-btn:not(:disabled):hover{background:var(--hover)}

/* Progress */
.progress-wrap{margin:16px 0 4px}
.progress-head{display:flex;justify-content:space-between;font-size:12px;color:var(--muted);margin-bottom:6px}
.progress{height:3px;background:var(--soft);border-radius:2px;overflow:hidden}
.progress i{display:block;height:100%;background:var(--accent);width:0;transition:width .3s}

/* Download button */
.download-btn{width:100%;border:0;padding:14px 16px;margin-top:12px;background:var(--accent);color:#fff;border-radius:8px;font:600 14px inherit;cursor:pointer;transition:.2s}
.download-btn:hover{background:var(--hover)}

/* Save panel */
.save-panel{margin-top:8px;display:flex;flex-direction:column;gap:6px}
.save-option{border:1px solid var(--line);background:var(--bg);padding:12px 14px;border-radius:8px;font:500 13px inherit;color:var(--ink);cursor:pointer;display:flex;align-items:center;gap:8px;transition:.15s}
.save-option:hover{border-color:var(--accent);background:var(--soft)}
.save-option span{font-size:16px}

/* ===== History ===== */
.history-section{margin-top:32px}
.history-header{display:flex;align-items:baseline;gap:8px;margin-bottom:14px}
.history-header h2{font-size:16px;font-weight:700;margin:0}
.history-count{font-size:12px;color:var(--muted)}
.history-list{display:flex;flex-direction:column;gap:8px}
.history-item{display:flex;align-items:center;gap:10px;background:var(--bg);border:1px solid var(--line);border-radius:10px;padding:10px 12px;transition:.2s}
.history-item:hover{border-color:var(--muted)}
.history-item-info{flex:1;min-width:0}
.history-item-info strong{display:block;font-size:13px;white-space:nowrap;overflow:hidden;text-overflow:ellipsis}
.history-item-info span{font-size:11px;color:var(--muted)}
.history-item audio{height:36px;max-width:140px;flex-shrink:0}
.history-download{flex-shrink:0;width:34px;height:34px;display:grid;place-items:center;background:var(--accent);color:#fff;border-radius:50%;text-decoration:none;font-size:14px;border:0;cursor:pointer;transition:.2s}
.history-download:hover{background:var(--hover);transform:scale(1.05)}
.history-delete{flex-shrink:0;width:30px;height:30px;display:grid;place-items:center;background:none;border:1px solid var(--line);border-radius:50%;color:var(--muted);font-size:12px;cursor:pointer;transition:.2s}
.history-delete:hover{border-color:var(--accent);color:var(--accent)}

/* ===== Footer ===== */
footer{text-align:center;padding:24px 0 0;color:var(--muted);font-size:11px;position:relative}
.admin-link{position:absolute;left:0;bottom:0;color:#ccc;cursor:pointer;font-size:11px;transition:.2s;user-select:none}
.admin-link:hover{color:var(--muted);text-decoration:underline}

/* ===== Toast ===== */
.toast{position:fixed;bottom:32px;left:50%;transform:translateX(-50%);background:var(--ink);color:#fff;padding:12px 24px;font-size:13px;border-radius:8px;z-index:9999;box-shadow:0 4px 20px rgba(0,0,0,.15);max-width:90vw;text-align:center;animation:toastIn .3s ease}
@keyframes toastIn{from{opacity:0;transform:translateX(-50%) translateY(12px)}to{opacity:1;transform:translateX(-50%) translateY(0)}}

/* ===== Payment Overlay ===== */
.payment-overlay{position:fixed;inset:0;background:rgba(0,0,0,.45);display:flex;align-items:center;justify-content:center;z-index:10000;animation:fadeIn .2s ease;backdrop-filter:blur(4px);-webkit-backdrop-filter:blur(4px)}
.payment-overlay[hidden]{display:none}
@keyframes fadeIn{from{opacity:0}to{opacity:1}}
.payment-card{background:var(--bg);border-radius:14px;padding:28px 24px 24px;width:90vw;max-width:340px;text-align:center;position:relative;box-shadow:0 8px 32px rgba(0,0,0,.12);animation:slideUp .3s ease}
@keyframes slideUp{from{opacity:0;transform:translateY(20px)}to{opacity:1;transform:translateY(0)}}
.payment-close{position:absolute;top:10px;right:14px;border:0;background:none;font-size:22px;color:var(--muted);cursor:pointer;padding:4px;line-height:1}
.payment-close:hover{color:var(--ink)}
.payment-title{font-size:17px;font-weight:700;margin-bottom:6px}
.payment-price{font-size:36px;font-weight:800;color:var(--accent);letter-spacing:-.02em;line-height:1.2}
.payment-desc{font-size:12px;color:var(--muted);margin-top:2px}

/* Loading spinner */
.payment-loading{padding:24px 0 16px}
.loading-spinner{width:32px;height:32px;border:3px solid var(--line);border-top-color:var(--accent);border-radius:50%;margin:0 auto 12px;animation:spin .8s linear infinite}
@keyframes spin{to{transform:rotate(360deg)}}
.payment-loading p{font-size:13px;color:var(--muted);margin:0}

/* QR code */
.payment-qr-wrap{padding:16px 0 8px}
.payment-qr{width:200px;height:200px;margin:0 auto 14px;border:1px solid var(--line);border-radius:8px;overflow:hidden;display:flex;align-items:center;justify-content:center;background:var(--bg)}
.payment-qr img{width:100%;height:100%;object-fit:contain}
.payment-hint{font-size:13px;color:var(--muted);margin:0 0 10px}
.payment-qr-actions{margin-top:4px}
.payment-copy-btn{border:1px solid var(--line);background:var(--bg);padding:10px 20px;border-radius:8px;font:500 13px inherit;color:var(--ink);cursor:pointer;display:inline-flex;align-items:center;gap:6px;transition:.15s}
.payment-copy-btn:hover{border-color:var(--accent);background:var(--soft)}

/* Success */
.payment-success{padding:20px 0 16px}
.success-check{width:48px;height:48px;border-radius:50%;background:#07c160;color:#fff;font-size:24px;display:grid;place-items:center;margin:0 auto 12px}
.payment-success p{font-size:15px;font-weight:600;margin:0 0 16px}
.payment-done-btn{border:0;padding:10px 32px;background:var(--accent);color:#fff;border-radius:8px;font:600 14px inherit;cursor:pointer;transition:.2s}
.payment-done-btn:hover{background:var(--hover)}

/* Error */
.payment-error{padding:16px 0}
.payment-error p{font-size:13px;color:#e04848;margin:0 0 12px}
.payment-retry-btn{border:1px solid var(--line);background:var(--bg);padding:8px 24px;border-radius:8px;font:500 13px inherit;color:var(--ink);cursor:pointer;transition:.15s}
.payment-retry-btn:hover{border-color:var(--accent)}

/* Polling */
.payment-polling{display:flex;align-items:center;justify-content:center;gap:8px;padding:8px 0 0;font-size:12px;color:var(--muted)}
.payment-polling[hidden]{display:none}
.polling-dot{width:8px;height:8px;border-radius:50%;background:var(--accent);animation:pulse 1s ease infinite}
@keyframes pulse{0%,100%{opacity:.3;transform:scale(.8)}50%{opacity:1;transform:scale(1.2)}}

/* ===== Admin ===== */
.admin-overlay{position:fixed;inset:0;background:rgba(0,0,0,.45);display:flex;align-items:center;justify-content:center;z-index:10001;animation:fadeIn .2s ease;backdrop-filter:blur(4px);-webkit-backdrop-filter:blur(4px)}
.admin-overlay[hidden]{display:none}
.admin-card{background:var(--bg);border-radius:14px;padding:28px 24px 24px;width:90vw;max-width:360px;position:relative;box-shadow:0 8px 32px rgba(0,0,0,.12);animation:slideUp .3s ease}
.admin-panel-card{max-width:380px}
.admin-close{position:absolute;top:10px;right:14px;border:0;background:none;font-size:22px;color:var(--muted);cursor:pointer;padding:4px;line-height:1}
.admin-close:hover{color:var(--ink)}
.admin-title{font-size:17px;font-weight:700;margin-bottom:20px;text-align:center}
.admin-form{display:flex;flex-direction:column;gap:14px}
.admin-field{display:flex;flex-direction:column;gap:4px}
.admin-field span{font-size:12px;color:var(--muted);font-weight:500}
.admin-field input{border:1px solid var(--line);border-radius:8px;padding:10px 12px;font:14px inherit;outline:0;transition:.15s}
.admin-field input:focus{border-color:var(--accent)}
.admin-error{font-size:12px;color:#e04848;margin:0;text-align:center}
.admin-submit{border:0;padding:12px;background:var(--accent);color:#fff;border-radius:8px;font:600 14px inherit;cursor:pointer;transition:.2s}
.admin-submit:hover{background:var(--hover)}

/* Admin panel stats */
.admin-stats{border:1px solid var(--line);border-radius:10px;padding:14px;margin-bottom:16px;display:flex;flex-direction:column;gap:10px}
.admin-stat-row{display:flex;justify-content:space-between;align-items:center}
.admin-stat-row strong{font-size:13px}
.admin-stat-row span{font-size:24px;font-weight:800;color:var(--accent)}
.admin-stat-detail{font-size:11px;color:var(--muted)}

/* Admin actions */
.admin-actions{display:flex;flex-direction:column;gap:12px;margin-bottom:16px}
.admin-action-row{display:flex;justify-content:space-between;align-items:center;font-size:13px;font-weight:500}
.admin-input{flex:1;margin-left:12px;border:1px solid var(--line);border-radius:6px;padding:6px 10px;font:12px inherit;outline:0;max-width:200px}
.admin-input:focus{border-color:var(--accent)}

/* Toggle switch */
.admin-toggle{display:inline-flex;align-items:center;gap:8px;cursor:pointer}
.admin-toggle input{display:none}
.admin-toggle-track{width:42px;height:24px;background:var(--line);border-radius:12px;position:relative;transition:.2s}
.admin-toggle-track::after{content:'';position:absolute;top:2px;left:2px;width:20px;height:20px;border-radius:50%;background:#fff;transition:.2s;box-shadow:0 1px 3px rgba(0,0,0,.15)}
.admin-toggle input:checked+.admin-toggle-track{background:#07c160}
.admin-toggle input:checked+.admin-toggle-track::after{left:20px}
.admin-toggle-label{font-size:12px;color:var(--muted);min-width:24px}

.admin-footer{text-align:center}
.admin-logout-btn{border:1px solid var(--line);background:var(--bg);padding:8px 24px;border-radius:8px;font:500 13px inherit;color:var(--muted);cursor:pointer;transition:.15s}
.admin-logout-btn:hover{border-color:#e04848;color:#e04848}
@media(max-width:480px){
  .shell{padding:40px 16px 32px}
  .hero{margin-bottom:28px}
  .hero h1{font-size:22px}
  .hero p{font-size:13px}
  .dropzone{padding:32px 16px}
  .controls{flex-direction:column}
  .convert-btn{width:100%;height:44px}
  .history-item{flex-wrap:wrap}
  .history-item audio{max-width:100%;flex:1 1 100%}
}