/* ===== 豆豆免费转换器 · 样式 ===== */
:root{
  --bg:#0f1117;
  --bg-2:#171a23;
  --panel:#1d212c;
  --panel-2:#232838;
  --border:#2c3142;
  --border-2:#3a4056;
  --text:#e6e9f2;
  --text-2:#9aa3bd;
  --text-3:#6b7392;
  --brand:#7c5cff;
  --brand-2:#9d7bff;
  --brand-grad:linear-gradient(135deg,#7c5cff 0%,#4d9fff 100%);
  --ok:#2ecc71;
  --warn:#f5a623;
  --err:#ff5c5c;
  --radius:14px;
  --radius-sm:9px;
  --shadow:0 8px 30px rgba(0,0,0,.35);
  --mono:'SFMono-Regular',Consolas,'Liberation Mono',Menlo,monospace;
}
*{box-sizing:border-box}
html,body{margin:0;height:100%}
body{
  font-family:-apple-system,BlinkMacSystemFont,'Segoe UI',PingFang SC,Microsoft YaHei,sans-serif;
  background:var(--bg);color:var(--text);font-size:14px;line-height:1.5;
  -webkit-font-smoothing:antialiased;
}
button{font-family:inherit;cursor:pointer}
input,select,textarea{font-family:inherit}

/* 布局 */
.app{display:flex;height:100vh;overflow:hidden}
.sidebar{
  width:248px;flex-shrink:0;background:var(--bg-2);
  display:flex;flex-direction:column;border-right:1px solid var(--border);
}
.brand{display:flex;align-items:center;gap:12px;padding:22px 20px}
.brand-logo{
  width:42px;height:42px;border-radius:12px;background:var(--brand-grad);
  display:flex;align-items:center;justify-content:center;font-size:22px;font-weight:800;color:#fff;
  box-shadow:0 6px 18px rgba(124,92,255,.45);
}
.brand-title{font-size:15px;font-weight:700}
.brand-sub{font-size:11px;color:var(--text-3);margin-top:2px}
.nav{flex:1;padding:10px 12px;display:flex;flex-direction:column;gap:3px;overflow:auto}
.nav-item{
  display:flex;align-items:center;gap:11px;width:100%;
  padding:11px 13px;border:none;background:transparent;color:var(--text-2);
  border-radius:10px;font-size:13.5px;text-align:left;transition:.15s;
}
.nav-item:hover{background:var(--panel);color:var(--text)}
.nav-item.active{background:var(--brand-grad);color:#fff;box-shadow:0 4px 14px rgba(124,92,255,.4)}
.nav-ico{font-size:16px;width:20px;text-align:center}
.sidebar-foot{padding:14px 18px;border-top:1px solid var(--border)}
.safe-badge{font-size:11px;color:var(--text-3);line-height:1.5}

/* 主区 */
.main{flex:1;display:flex;flex-direction:column;overflow:hidden}
.topbar{padding:24px 32px 0;border-bottom:1px solid var(--border);background:linear-gradient(180deg,var(--bg-2) 0,transparent 140px)}
.topbar h1{margin:0;font-size:22px;font-weight:700}
.topbar p{margin:6px 0 18px;color:var(--text-2);font-size:13px}
.content{flex:1;overflow:auto;padding:26px 32px 48px}

/* 通用控件 */
.card{background:var(--panel);border:1px solid var(--border);border-radius:var(--radius);padding:22px;margin-bottom:20px}
.card-h{display:flex;align-items:center;justify-content:space-between;margin-bottom:16px;flex-wrap:wrap;gap:10px}
.card-h h3{margin:0;font-size:15px;font-weight:600}
.hint{font-size:12px;color:var(--text-3)}
.grid{display:grid;gap:16px}
.row{display:flex;gap:12px;align-items:center;flex-wrap:wrap}
.field{display:flex;flex-direction:column;gap:6px}
.field label{font-size:12px;color:var(--text-2);font-weight:500}
.input,.select,.textarea{
  background:var(--bg);border:1px solid var(--border-2);color:var(--text);
  border-radius:9px;padding:9px 12px;font-size:13px;outline:none;transition:.15s;width:100%;
}
.input:focus,.select:focus,.textarea:focus{border-color:var(--brand);box-shadow:0 0 0 3px rgba(124,92,255,.18)}
.textarea{resize:vertical;min-height:120px;font-family:var(--mono);line-height:1.6}
.select{cursor:pointer}
.btn{
  background:var(--brand-grad);color:#fff;border:none;border-radius:9px;
  padding:9px 18px;font-size:13px;font-weight:600;transition:.15s;
}
.btn:hover{filter:brightness(1.08);box-shadow:0 5px 16px rgba(124,92,255,.4)}
.btn:active{transform:translateY(1px)}
.btn.ghost{background:var(--panel-2);color:var(--text);border:1px solid var(--border-2)}
.btn.ghost:hover{background:var(--border)}
.btn.sm{padding:6px 13px;font-size:12px}
.btn:disabled{opacity:.5;cursor:not-allowed;filter:none;box-shadow:none}
.tag{display:inline-flex;align-items:center;gap:5px;padding:3px 9px;border-radius:6px;background:var(--panel-2);font-size:11px;color:var(--text-2);border:1px solid var(--border-2)}
.tag.ok{background:rgba(46,204,113,.12);color:#5fdc8b;border-color:rgba(46,204,113,.3)}

/* 拖放上传 */
.dropzone{
  border:2px dashed var(--border-2);border-radius:var(--radius);padding:38px 20px;
  text-align:center;transition:.18s;cursor:pointer;background:var(--panel);
}
.dropzone:hover,.dropzone.drag{border-color:var(--brand);background:rgba(124,92,255,.06)}
.dropzone .ico{font-size:34px;margin-bottom:8px}
.dropzone .t1{font-size:14px;font-weight:600}
.dropzone .t2{font-size:12px;color:var(--text-3);margin-top:4px}
.dropzone input{display:none}

/* 文件信息 */
.filelist{display:flex;flex-direction:column;gap:10px}
.fileitem{
  display:flex;align-items:center;gap:12px;padding:12px 14px;
  background:var(--bg);border:1px solid var(--border);border-radius:10px;
}
.fileicon{width:38px;height:38px;border-radius:8px;background:var(--panel-2);display:flex;align-items:center;justify-content:center;font-size:18px;flex-shrink:0}
.filemeta{flex:1;min-width:0}
.filemeta .fn{font-size:13px;font-weight:500;white-space:nowrap;overflow:hidden;text-overflow:ellipsis}
.filemeta .fs{font-size:11px;color:var(--text-3);margin-top:2px}
.filedel{background:transparent;border:none;color:var(--text-3);font-size:18px;padding:4px 8px;border-radius:6px}
.filedel:hover{color:var(--err);background:rgba(255,92,92,.1)}

/* 预览 */
.preview-box{display:flex;gap:20px;flex-wrap:wrap;align-items:flex-start}
.preview-img{max-width:100%;max-height:340px;border-radius:10px;border:1px solid var(--border);background:#000}
.preview-empty{color:var(--text-3);font-size:13px;padding:30px;text-align:center;width:100%}

/* 进度条 */
.progress{height:8px;background:var(--bg);border-radius:6px;overflow:hidden;border:1px solid var(--border)}
.progress-bar{height:100%;width:0;background:var(--brand-grad);transition:width .2s}

/* 结果输出 */
.output{background:var(--bg);border:1px solid var(--border);border-radius:9px;padding:12px;font-family:var(--mono);font-size:12.5px;white-space:pre-wrap;word-break:break-word;max-height:340px;overflow:auto;line-height:1.6}
.output:empty::before{content:'结果将显示在这里…';color:var(--text-3)}

/* 颜色模块 */
.color-stage{display:flex;gap:18px;align-items:center;flex-wrap:wrap}
.color-swatch{width:120px;height:120px;border-radius:14px;border:1px solid var(--border);box-shadow:var(--shadow)}

/* 单位模块 */
.unit-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(220px,1fr));gap:12px}
.unit-cat{background:var(--bg);border:1px solid var(--border);border-radius:10px;padding:14px}
.unit-cat .t{font-size:12px;color:var(--text-2);margin-bottom:10px;font-weight:600}
.unit-line{display:flex;gap:8px;margin-bottom:8px;align-items:center}
.unit-line:last-child{margin-bottom:0}
.unit-line .input{flex:1}

/* Toast */
.toast{
  position:fixed;bottom:28px;left:50%;transform:translateX(-50%) translateY(20px);
  background:var(--panel-2);color:var(--text);border:1px solid var(--border-2);
  padding:11px 20px;border-radius:10px;font-size:13px;box-shadow:var(--shadow);
  opacity:0;pointer-events:none;transition:.25s;z-index:9999;
}
.toast.show{opacity:1;transform:translateX(-50%) translateY(0)}
.toast.err{border-color:var(--err);color:#ffb3b3}
.toast.ok{border-color:var(--ok);color:#9be8b8}

/* 全局拖放遮罩 */
.drop-overlay{
  position:fixed;inset:0;background:rgba(124,92,255,.15);backdrop-filter:blur(3px);
  display:none;align-items:center;justify-content:center;z-index:9998;pointer-events:none;
}
.drop-overlay.show{display:flex}
.drop-text{font-size:20px;font-weight:700;color:#fff;background:var(--brand-grad);padding:20px 40px;border-radius:14px;box-shadow:var(--shadow)}

/* range */
input[type=range]{-webkit-appearance:none;height:6px;background:var(--bg);border-radius:4px;outline:none}
input[type=range]::-webkit-slider-thumb{-webkit-appearance:none;width:16px;height:16px;border-radius:50%;background:var(--brand);cursor:pointer;box-shadow:0 2px 6px rgba(0,0,0,.4)}
.range-val{font-size:12px;color:var(--text-2);min-width:42px;text-align:right;font-family:var(--mono)}

/* checkbox */
.chk{display:flex;align-items:center;gap:8px;font-size:13px;color:var(--text-2);cursor:pointer}
.chk input{width:16px;height:16px;accent-color:var(--brand)}

/* 响应式 */
@media(max-width:880px){
  .app{flex-direction:column}
  .sidebar{width:100%;flex-direction:row;overflow-x:auto;height:auto}
  .brand{padding:12px 14px}
  .nav{flex-direction:row;padding:0 8px}
  .nav-item{white-space:nowrap}
  .sidebar-foot{display:none}
  .content{padding:18px}
  .topbar{padding:16px 18px 0}
}