:root{
  --bg:#f6f8fb;
  --panel:#ffffff;
  --muted:#687085;
  --accent:#0ea5a4;
  --accent-2:#06b6d4;
  --shadow: 0 8px 20px rgba(11, 18, 33, 0.06);
  --radius:12px;
  --monospace: ui-monospace, SFMono-Regular, Menlo, Monaco, "Roboto Mono", monospace;
  font-family: Inter, system-ui, -apple-system, "Segoe UI", Roboto, "Helvetica Neue", Arial;
}

*{box-sizing:border-box}
html,body{height:100%;margin:0;background:linear-gradient(180deg,#eef2f7,#f6f8fb);color:#0b1320}
.app{max-width:1200px;margin:28px auto;border-radius:14px;overflow:hidden;box-shadow:var(--shadow);background:linear-gradient(180deg, #ffffff, #fbfdff)}
.topbar{display:flex;align-items:center;gap:16px;padding:16px 20px;border-bottom:1px solid #eef2f7}
.logo{font-weight:700;font-size:20px;color:var(--accent-2)}
.topbar nav{display:flex;gap:8px;flex-wrap:wrap}
.tool-btn{background:transparent;border:1px solid transparent;padding:8px 12px;border-radius:10px;cursor:pointer;color:var(--muted)}
.tool-btn.active{background:linear-gradient(90deg,var(--accent),#06b6d4);color:white;border-color:rgba(6,182,212,0.2);box-shadow:0 6px 18px rgba(6,182,212,0.08)}
.spacer{flex:1}
.help{font-size:13px;color:var(--muted)}

.main{display:flex;gap:18px;padding:18px}
.left{flex:0 0 360px;padding:6px 12px}
.right{flex:1;display:flex;flex-direction:column;gap:12px;padding:6px 12px}

.uploader{background:var(--panel);padding:12px;border-radius:10px;border:1px solid #f0f4f7;box-shadow:var(--shadow)}
.dropzone{height:140px;border-radius:8px;border:2px dashed #e6eef8;display:flex;align-items:center;justify-content:center;cursor:pointer;background:linear-gradient(180deg,rgba(6,182,212,0.02),transparent)}
.dropzone .drop-inner{color:var(--muted);text-align:center}
#fileInput{display:none}

.options{background:var(--panel);border-radius:10px;padding:12px;margin-top:12px;border:1px solid #f0f4f7;box-shadow:var(--shadow)}
.option-row{display:flex;align-items:center;gap:8px;margin-bottom:10px}
.option-row label{flex:0 0 120px;color:var(--muted);font-size:13px}
.option-row input[type="range"]{flex:1}
.option-row select,input[type=number],input[type=text]{flex:1;padding:8px;border-radius:8px;border:1px solid #e8eef6}
.primary{background:linear-gradient(90deg,var(--accent),var(--accent-2));color:white;border:none;padding:10px 12px;border-radius:8px;cursor:pointer}
.secondary{background:transparent;border:1px solid #e6eef8;padding:10px 12px;border-radius:8px;cursor:pointer}

.log{margin-top:12px;background:#ffffff;border-radius:10px;padding:12px;border:1px solid #f0f4f7;color:var(--muted);font-family:var(--monospace);font-size:13px;min-height:56px}

.panel{background:var(--panel);border-radius:10px;padding:14px;border:1px solid #f0f4f7;box-shadow:var(--shadow)}
.file-list{display:flex;flex-direction:column;gap:8px;max-height:360px;overflow:auto;padding-right:6px}
.file-item{display:flex;align-items:center;gap:10px;padding:8px;border-radius:8px;border:1px solid #f4f7fb}
.file-thumb{width:56px;height:56px;border-radius:6px;background:#f7fbff;display:flex;align-items:center;justify-content:center;overflow:hidden}
.file-meta{flex:1}
.file-name{font-weight:600;font-size:14px}
.file-sub{font-size:12px;color:var(--muted)}
.file-actions{display:flex;gap:6px}
.small-btn{padding:6px 8px;border:1px solid #e8eef6;border-radius:8px;background:transparent;cursor:pointer;font-size:13px}

.preview-area{min-height:160px;border-radius:8px;background:linear-gradient(180deg,#fafcff,#ffffff);padding:12px;border:1px dashed #eef6fb;display:flex;flex-wrap:wrap;gap:12px;align-items:flex-start}
.preview-thumb{width:140px;border-radius:8px;padding:6px;background:#fff;border:1px solid #eef4f9;box-shadow:0 6px 18px rgba(12,20,36,0.04)}
.preview-thumb img{display:block;max-width:100%;height:auto;border-radius:6px}
.results-area{margin-top:10px;display:flex;gap:8px;flex-wrap:wrap}
.result-link{display:inline-block;padding:8px 10px;border-radius:8px;background:linear-gradient(90deg,#fff,#f7fffe);border:1px solid #e6f9f8;color:var(--accent-2);text-decoration:none;font-weight:600}

.footer{padding:12px 18px;border-top:1px solid #eef2f7;color:var(--muted);font-size:13px}
@media (max-width:880px){
  .main{flex-direction:column}
  .left{width:100%}
}