:root{
  --bg:#0e1013;
  --card:#161a21;
  --card2:#1d222c;
  --line:#2a3140;
  --text:#e9ecf2;
  --muted:#98a2b3;
  --accent:#4cc9f0;
  --accent2:#5470f0;
  --danger:#ff7676;
}
*{box-sizing:border-box}
html,body{margin:0;padding:0}
body{
  background:
    radial-gradient(1100px 500px at 75% -10%, rgba(84,112,240,.18), transparent 60%),
    radial-gradient(900px 420px at 8% 110%, rgba(76,201,240,.10), transparent 55%),
    var(--bg);
  color:var(--text);
  font-family:system-ui,-apple-system,"PingFang SC","Hiragino Sans GB","Microsoft YaHei",sans-serif;
  min-height:100vh;
}
.hidden{display:none!important}
:focus-visible{outline:2px solid var(--accent);outline-offset:2px;border-radius:6px}

/* ---------- 顶栏 ---------- */
.topbar{
  display:flex;justify-content:space-between;align-items:flex-start;gap:16px;flex-wrap:wrap;
  max-width:1180px;margin:0 auto;padding:22px 20px 10px;
}
.brand{display:flex;align-items:center;gap:14px}
.logo{
  width:42px;height:42px;border-radius:12px;flex:none;
  display:flex;align-items:center;justify-content:center;font-size:20px;color:#fff;
  background:linear-gradient(135deg,var(--accent),var(--accent2));
  box-shadow:0 4px 18px rgba(84,112,240,.35);
}
.brand h1{margin:0;font-size:20px;letter-spacing:.02em}
.brand .sub{margin:2px 0 0;font-size:12.5px;color:var(--muted)}
.recipe{max-width:500px;font-size:12.5px;color:var(--muted)}
.recipe summary{cursor:pointer;color:var(--accent);font-size:13px;user-select:none}
.recipe p{margin:8px 0 0;line-height:1.75}
.recipe code{
  background:var(--card2);border:1px solid var(--line);border-radius:6px;
  padding:1px 6px;font-size:12px;
}

/* ---------- 上传区 ---------- */
.dropzone{
  max-width:1180px;margin:26px auto 0;
  border:1.5px dashed #35405480;border-radius:18px;
  padding:72px 24px;text-align:center;cursor:pointer;
  transition:border-color .2s,background .2s,transform .15s;
}
.dropzone:hover,.dropzone.dragover{
  border-color:var(--accent);
  background:rgba(76,201,240,.06);
}
.dropzone.dragover{transform:scale(1.005)}
.dz-icon{font-size:44px;line-height:1}
.dz-main{margin:16px 0 6px;font-size:17px}
.dz-main b{color:var(--accent)}
.dz-sub{margin:0;font-size:13px;color:var(--muted)}

/* ---------- 工作区布局 ---------- */
main{max-width:1180px;margin:0 auto;padding:20px}
.workspace{
  display:grid;grid-template-columns:minmax(0,1fr) 340px;gap:20px;align-items:start;
}

/* ---------- 预览 / 对比 ---------- */
.viewer{
  background:var(--card);border:1px solid var(--line);border-radius:16px;
  padding:16px;min-width:0;
}
.viewer-toolbar{
  display:flex;justify-content:space-between;align-items:center;gap:10px;
  margin-bottom:12px;flex-wrap:wrap;
}
.viewer-toolbar .hint{font-size:12px;color:var(--muted)}
.compare{
  position:relative;display:inline-block;max-width:100%;
  border-radius:12px;overflow:hidden;line-height:0;
  box-shadow:0 6px 28px rgba(0,0,0,.45);
  cursor:ew-resize;touch-action:none;
  --pos:50%;
}
#beforeCanvas{display:block;max-width:100%;max-height:66vh;width:auto;height:auto}
#afterCanvas{
  position:absolute;inset:0;width:100%;height:100%;
  clip-path:inset(0 0 0 var(--pos));
}
.divider{
  position:absolute;top:0;bottom:0;left:var(--pos);width:2px;
  transform:translateX(-1px);background:#fff;
  box-shadow:0 0 0 1px rgba(0,0,0,.35);
  pointer-events:none;
}
.knob{
  position:absolute;top:50%;left:50%;transform:translate(-50%,-50%);
  width:34px;height:34px;border-radius:50%;
  background:#fff;color:#111;font-size:15px;
  display:flex;align-items:center;justify-content:center;line-height:1;
  box-shadow:0 2px 12px rgba(0,0,0,.55);
  pointer-events:none;
}
.tag{
  position:absolute;top:10px;font-size:12px;line-height:1.4;
  padding:3px 10px;border-radius:999px;color:#fff;
  background:rgba(0,0,0,.55);backdrop-filter:blur(4px);
  pointer-events:none;
}
.tag-before{left:10px}
.tag-after{right:10px;background:rgba(84,112,240,.85)}
.img-info{margin:12px 0 0;font-size:12px;color:var(--muted);text-align:center}

/* 忙碌遮罩 */
.busy{
  position:absolute;inset:0;z-index:6;
  display:flex;flex-direction:column;gap:12px;align-items:center;justify-content:center;
  background:rgba(8,10,14,.62);backdrop-filter:blur(2px);
  line-height:1.5;font-size:13px;
}
.spin{
  width:34px;height:34px;border-radius:50%;
  border:3px solid rgba(255,255,255,.25);border-top-color:var(--accent);
  animation:spin .8s linear infinite;
}
@keyframes spin{to{transform:rotate(360deg)}}

/* ---------- 右侧面板 ---------- */
.panel{display:flex;flex-direction:column;gap:16px}
.card{
  background:var(--card);border:1px solid var(--line);border-radius:16px;padding:16px;
}
.card h2{
  margin:0 0 12px;font-size:13px;font-weight:600;color:var(--muted);
  letter-spacing:.08em;display:flex;align-items:center;gap:8px;
}
.badge{
  font-size:11px;letter-spacing:0;color:var(--accent);
  border:1px solid rgba(76,201,240,.4);border-radius:999px;padding:1px 8px;
}

/* 预设 */
.preset-grid{display:grid;grid-template-columns:1fr 1fr;gap:8px}
.preset{
  display:flex;flex-direction:column;gap:3px;text-align:left;
  padding:9px 11px;border-radius:11px;cursor:pointer;
  background:var(--card2);border:1px solid var(--line);color:var(--text);
  transition:border-color .15s,background .15s;
}
.preset:hover{border-color:#3d4a63}
.preset.active{border-color:var(--accent);background:rgba(76,201,240,.08)}
.preset.active .pname{color:var(--accent)}
.pname{font-size:13px;font-weight:600}
.pdesc{font-size:11px;color:var(--muted)}

/* 滑杆 */
.slider-list{display:flex;flex-direction:column;gap:10px}
.slider-row{
  display:grid;grid-template-columns:52px 1fr 40px;align-items:center;gap:10px;
  cursor:default;
}
.s-name{font-size:13px;color:var(--text)}
.slider-row input[type=range]{width:100%;accent-color:var(--accent);cursor:pointer;margin:0}
.slider-row output{
  font-size:12px;color:var(--muted);text-align:right;
  font-variant-numeric:tabular-nums;
}

/* 操作区 */
.actions{display:flex;gap:8px;margin-bottom:10px}
.actions .select{flex:1}
.btn{
  border-radius:10px;border:1px solid var(--line);cursor:pointer;
  padding:10px 14px;font-size:14px;color:var(--text);
  background:var(--card2);transition:filter .15s,border-color .15s,opacity .15s;
}
.btn:hover{filter:brightness(1.15)}
.btn.small{padding:6px 10px;font-size:12.5px}
.btn.primary{
  width:100%;border:none;color:#fff;font-weight:600;
  background:linear-gradient(135deg,var(--accent),var(--accent2));
  box-shadow:0 4px 16px rgba(84,112,240,.35);
}
.btn.ghost{background:transparent}
.btn:disabled{opacity:.5;cursor:not-allowed}
.select{
  background:var(--card2);color:var(--text);
  border:1px solid var(--line);border-radius:10px;padding:8px 10px;font-size:13px;
}
.tip{margin:10px 0 0;font-size:11.5px;color:var(--muted);line-height:1.6}

/* ---------- 其他 ---------- */
footer{
  text-align:center;color:var(--muted);font-size:12px;
  padding:10px 16px 30px;
}
.toast{
  position:fixed;left:50%;bottom:26px;z-index:50;
  transform:translate(-50%,10px);opacity:0;pointer-events:none;
  background:#2b1216;border:1px solid var(--danger);color:#ffc2c2;
  padding:10px 18px;border-radius:10px;font-size:13px;
  transition:opacity .25s,transform .25s;
}
.toast.show{opacity:1;transform:translate(-50%,0)}

/* ---------- 响应式 ---------- */
@media (max-width:920px){
  .workspace{grid-template-columns:1fr}
  #beforeCanvas{max-height:56vh}
  .dropzone{padding:52px 20px}
  .recipe{max-width:100%}
}