:root{--ac-primary: #6c5ce7;--ac-primary-light: #a29bfe;--ac-primary-dark: #5641d4;--ac-bg: #ffffff;--ac-bg-gray: #f8f9fc;--ac-text: #2d3436;--ac-text-secondary: #636e72;--ac-text-light: #b2bec3;--ac-border: #e9ecef;--ac-shadow: 0 2px 12px rgba(0, 0, 0, .06);--ac-green: #00b894;--ac-radius: 8px}*,*:before,*:after{box-sizing:border-box;margin:0;padding:0}body{min-height:100vh;background:var(--ac-bg-gray);color:var(--ac-text);font-family:-apple-system,BlinkMacSystemFont,Segoe UI,Roboto,Oxygen,Ubuntu,sans-serif;line-height:1.6}body.conversion-active{overflow:hidden}.page{display:flex;min-height:100vh;flex-direction:column}.navbar{position:sticky;top:0;z-index:100;border-bottom:1px solid var(--ac-border);background:#ffffffeb;backdrop-filter:blur(12px);-webkit-backdrop-filter:blur(12px)}.navbar-inner{display:flex;width:100%;max-width:1100px;height:56px;margin:0 auto;padding:0 32px;align-items:center;gap:20px}.navbar-back{display:flex;align-items:center;gap:6px;color:var(--ac-text-secondary);font-size:14px;text-decoration:none;transition:color .2s}.navbar-back:before{width:16px;height:16px;content:"";background-color:currentColor;mask:url(../icons/common/arrow_back.png) center/contain no-repeat;-webkit-mask:url(../icons/common/arrow_back.png) center/contain no-repeat}.navbar-back:hover{color:var(--ac-primary)}.navbar-title{font-size:17px;font-weight:700}.main{flex:1;padding:32px 0}.container{width:100%;max-width:1100px;margin:0 auto;padding:0 32px}.hero{display:flex;margin-bottom:24px;align-items:center;gap:18px}.hero-icon{width:52px;height:52px;flex:0 0 auto;color:var(--ac-primary);background-color:currentColor;mask:url(../icons/common/swap_horiz.png) center/contain no-repeat;-webkit-mask:url(../icons/common/swap_horiz.png) center/contain no-repeat}.hero h1{font-size:28px;line-height:1.25}.hero p{margin-top:6px;color:var(--ac-text-secondary);font-size:14px}.grid{display:grid;grid-template-columns:minmax(0,1fr) 340px;gap:24px}.panel{border:1px solid var(--ac-border);border-radius:var(--ac-radius);background:var(--ac-bg)}.panel-header{display:flex;padding:20px 24px;align-items:center;justify-content:space-between;gap:16px;border-bottom:1px solid var(--ac-border)}.panel-header h2{font-size:16px;font-weight:700}.panel-hint{color:var(--ac-text-light);font-size:12px}.panel-upload{padding-bottom:20px}.dropzone{display:flex;min-height:244px;margin:24px;padding:36px 24px;align-items:center;justify-content:center;flex-direction:column;gap:8px;border:2px dashed var(--ac-border);border-radius:var(--ac-radius);background:var(--ac-bg-gray);cursor:pointer;text-align:center;transition:border-color .2s,background .2s,transform .2s}.dropzone:hover,.dropzone.dragover{border-color:var(--ac-primary-light);background:#6c5ce70f}.dropzone.dragover{transform:scale(1.01)}.dropzone.is-busy{cursor:wait;opacity:.65}.dropzone input{position:absolute;width:1px;height:1px;overflow:hidden;clip:rect(0,0,0,0)}.dropzone-icon{display:block;width:52px;height:52px;color:var(--ac-primary);background-color:currentColor;mask:url(../icons/common/folder_open.png) center/contain no-repeat;-webkit-mask:url(../icons/common/folder_open.png) center/contain no-repeat}.dropzone-title{font-size:18px;font-weight:700}.dropzone-sub{color:var(--ac-text-secondary);font-size:14px}.file-info{margin:0 24px;padding:16px;border:1px solid var(--ac-border);border-radius:var(--ac-radius)}.file-info[hidden],.directory-panel[hidden],.field[hidden],.structure-option[hidden],.output-warnings[hidden]{display:none}.file-name{overflow:hidden;font-size:14px;font-weight:700;text-overflow:ellipsis;white-space:nowrap}.file-meta{margin-top:2px;color:var(--ac-text-secondary);font-size:13px}.file-stats{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));margin-top:12px;gap:8px}.file-stats:empty{display:none}.file-stats div{padding:8px 10px;background:var(--ac-bg-gray);color:var(--ac-text-secondary);font-size:12px}.directory-panel{margin:0 24px;overflow:hidden;border:1px solid var(--ac-border);border-radius:var(--ac-radius)}.directory-header{display:flex;padding:11px 14px;align-items:center;justify-content:space-between;gap:12px;border-bottom:1px solid var(--ac-border);background:var(--ac-bg-gray);font-size:13px}.directory-header span{color:var(--ac-primary);font-size:12px;font-weight:700}.audio-tree,.audio-tree ul{margin:0;padding:0;list-style:none}.audio-tree{max-height:300px;padding:8px;overflow:auto}.audio-tree ul{padding-left:24px}.audio-tree-row{display:flex;min-width:0;padding:6px 8px;align-items:center;gap:8px;border-radius:4px;cursor:pointer}.audio-tree-row:hover{background:var(--ac-bg-gray)}.audio-tree-row input{width:16px;height:16px;flex:0 0 auto;accent-color:var(--ac-primary);cursor:pointer}.audio-tree-icon{width:17px;height:17px;flex:0 0 auto;background-color:currentColor;mask-position:center;mask-repeat:no-repeat;mask-size:contain;-webkit-mask-position:center;-webkit-mask-repeat:no-repeat;-webkit-mask-size:contain}.audio-tree-icon-directory{color:var(--ac-primary);mask-image:url(../icons/common/folder_open.png);-webkit-mask-image:url(../icons/common/folder_open.png)}.audio-tree-icon-file{color:var(--ac-text-secondary);mask-image:url(../icons/common/audiotrack.png);-webkit-mask-image:url(../icons/common/audiotrack.png)}.audio-tree-name{min-width:0;overflow:hidden;font-size:13px;text-overflow:ellipsis;white-space:nowrap}.panel-settings{display:flex;flex-direction:column}.form-grid{display:flex;padding:24px;flex-direction:column;gap:16px}.field{display:flex;flex-direction:column;gap:7px}.field>span{font-size:13px;font-weight:600}.field select{width:100%;height:42px;padding:0 36px 0 12px;border:1px solid var(--ac-border);border-radius:6px;outline:none;background:var(--ac-bg);color:var(--ac-text);font:inherit;font-size:14px;cursor:pointer;transition:border-color .2s,box-shadow .2s}.field select:hover{border-color:var(--ac-primary-light)}.field select:focus{border-color:var(--ac-primary);box-shadow:0 0 0 3px #6c5ce71a}.folder-picker-dropzone{display:flex;padding:10px;flex-direction:column;gap:7px;border:1px dashed var(--ac-border);border-radius:6px;background:var(--ac-bg-gray);transition:border-color .2s,background .2s}.folder-picker-dropzone.dragover{border-color:var(--ac-primary);background:#6c5ce714}.folder-picker-actions{display:grid;grid-template-columns:1fr auto;gap:8px}.folder-picker-button,.folder-clear-button{height:40px;padding:0 12px;border:1px solid var(--ac-border);border-radius:6px;background:var(--ac-bg-gray);color:var(--ac-text-secondary);font:inherit;font-size:13px;font-weight:600;cursor:pointer;transition:border-color .2s,color .2s,background .2s}.folder-picker-button:hover:not(:disabled),.folder-clear-button:hover:not(:disabled){border-color:var(--ac-primary-light);color:var(--ac-primary)}.folder-picker-button:disabled,.folder-clear-button:disabled{cursor:not-allowed;opacity:.45}.folder-clear-button{background:var(--ac-bg)}.folder-clear-button[hidden]{display:none}.folder-picker-name{display:block;overflow:hidden;color:var(--ac-text-light);font-size:12px;text-overflow:ellipsis;white-space:nowrap}.structure-option{display:flex;padding:11px 12px;align-items:flex-start;gap:9px;border:1px solid var(--ac-border);border-radius:6px;background:var(--ac-bg-gray);cursor:pointer}.structure-option input{width:16px;height:16px;margin-top:2px;flex:0 0 auto;accent-color:var(--ac-primary);cursor:pointer}.structure-option input:disabled{cursor:not-allowed}.structure-option span{display:flex;min-width:0;flex-direction:column;gap:1px}.structure-option strong{font-size:13px;font-weight:600}.structure-option small{color:var(--ac-text-light);font-size:12px}.action-row{display:grid;grid-template-columns:1fr auto;padding:0 24px 20px;gap:10px}.btn{display:inline-flex;min-height:42px;padding:8px 18px;align-items:center;justify-content:center;border:1px solid transparent;border-radius:6px;font:inherit;font-size:14px;font-weight:700;text-decoration:none;cursor:pointer;transition:background .2s,border-color .2s,color .2s,box-shadow .2s}.btn.primary{background:var(--ac-primary);color:#fff}.btn.primary:hover:not(:disabled):not(.is-disabled){background:var(--ac-primary-dark);box-shadow:0 2px 8px #6c5ce74d}.btn.ghost{border-color:var(--ac-border);background:var(--ac-bg-gray);color:var(--ac-text-secondary)}.btn.ghost:hover:not(:disabled){border-color:var(--ac-primary-light);color:var(--ac-primary)}.btn:disabled,.btn.is-disabled{cursor:not-allowed;opacity:.45;pointer-events:none}.btn[hidden]{display:none}.conversion-overlay{position:fixed;top:0;right:0;bottom:0;left:0;z-index:1000;display:flex;padding:20px;align-items:center;justify-content:center;background:#12141ccc}.conversion-overlay[hidden]{display:none}.conversion-dialog{width:min(420px,100%);padding:30px;border:1px solid var(--ac-border);border-radius:var(--ac-radius);background:var(--ac-bg);box-shadow:0 18px 50px #00000047;text-align:center}.conversion-icon{width:42px;height:42px;margin:0 auto 12px;color:var(--ac-primary);background-color:currentColor;mask:url(../icons/common/audiotrack.png) center/contain no-repeat;-webkit-mask:url(../icons/common/audiotrack.png) center/contain no-repeat}.conversion-dialog h2{font-size:19px;font-weight:700}.status-text{min-height:42px;margin-top:8px;overflow-wrap:anywhere;color:var(--ac-text-secondary);font-size:13px}.progress-head{display:flex;margin:18px 0 8px;align-items:center;justify-content:space-between;gap:12px;color:var(--ac-text-secondary);font-size:12px}.progress-meta{color:var(--ac-primary);font-weight:700}.progress{height:9px;overflow:hidden;border-radius:3px;background:var(--ac-border)}.progress-bar{width:0;height:100%;background:linear-gradient(90deg,var(--ac-primary),var(--ac-primary-light));transition:width .2s}.cancel-conversion-button{min-width:120px;height:40px;margin-top:24px;padding:0 16px;border:1px solid var(--ac-border);border-radius:6px;background:var(--ac-bg-gray);color:var(--ac-text-secondary);font:inherit;font-size:13px;font-weight:700;cursor:pointer;transition:border-color .2s,color .2s,background .2s}.cancel-conversion-button:hover:not(:disabled){border-color:#d63031;background:#d630310f;color:#d63031}.cancel-conversion-button:disabled{cursor:wait;opacity:.65}.panel-output{margin-top:24px}.output-row{display:flex;padding:20px 24px;align-items:center;justify-content:space-between;gap:20px}.output-card{display:flex;min-width:0;align-items:center;gap:14px}.output-icon{width:36px;height:36px;flex:0 0 auto;color:var(--ac-green);background-color:currentColor;mask:url(../icons/common/audiotrack.png) center/contain no-repeat;-webkit-mask:url(../icons/common/audiotrack.png) center/contain no-repeat}.output-content{min-width:0}.output-title{overflow:hidden;font-size:14px;font-weight:700;text-overflow:ellipsis;white-space:nowrap}.output-meta{margin-top:2px;color:var(--ac-text-secondary);font-size:13px}.output-warnings{margin:0 24px 20px;padding:12px 14px;border-left:3px solid #e1a700;background:#fff9e6;color:#7a5b00;font-size:12px;white-space:pre-line}.footer{margin-top:auto;padding:24px 0;border-top:1px solid var(--ac-border);background:var(--ac-bg)}.footer-inner{display:flex;max-width:1100px;margin:0 auto;padding:0 32px;align-items:center;justify-content:space-between}.footer-brand{display:flex;align-items:center;gap:6px;color:var(--ac-primary);font-size:16px;font-weight:700;text-decoration:none}.footer-icon{width:20px;height:20px;background-color:currentColor;mask:url(../icons/common/bolt.png) center/contain no-repeat;-webkit-mask:url(../icons/common/bolt.png) center/contain no-repeat}@media (max-width: 800px){.navbar-inner,.container,.footer-inner{padding-right:16px;padding-left:16px}.main{padding:24px 0}.grid{grid-template-columns:1fr}.dropzone{min-height:190px}}@media (max-width: 560px){.hero{align-items:flex-start}.hero-icon{width:40px;height:40px}.hero h1{font-size:23px}.panel-header,.output-row{padding-right:16px;padding-left:16px}.dropzone{margin:16px;padding:28px 16px}.file-info,.directory-panel{margin:0 16px}.file-stats{grid-template-columns:1fr}.form-grid{padding:20px 16px}.action-row{padding:0 16px 16px}.conversion-dialog{padding:24px 18px}.output-row{align-items:stretch;flex-direction:column}.output-row .btn{width:100%}.output-warnings{margin-right:16px;margin-left:16px}.footer-inner{flex-direction:column;gap:8px;text-align:center}}