:root{--bg:#f5f5f7;--panel:#ffffff;--text:#1d1d1f;--muted:#6e6e73;--accent:#007aff;--border:#d2d2d7}
*{box-sizing:border-box}
html,body{height:100%}
body{margin:0;background:var(--bg);color:var(--text);font-family:-apple-system,BlinkMacSystemFont,"SF Pro Text","SF Pro Display","Segoe UI",Roboto,"Helvetica Neue",Arial,sans-serif}
.app-header,.app-footer{padding:20px 24px;background:var(--panel);border-bottom:1px solid var(--border)}
.app-header{font-size:28px;font-weight:700;letter-spacing:-0.01em}
.app-footer{border-top:1px solid var(--border);border-bottom:none;color:var(--muted)}
.container{display:grid;grid-template-columns:360px 1fr;gap:24px;padding:0 24px;max-width:1080px;margin:24px auto}
.controls{background:var(--panel);padding:18px;border:1px solid var(--border);border-radius:14px;display:flex;flex-direction:column;gap:18px;box-shadow:0 1px 3px rgba(0,0,0,.06)}
.group{display:flex;flex-direction:column;gap:10px}
.group-title{font-weight:600;color:var(--text);letter-spacing:-0.01em}
.file-input{display:flex;flex-direction:column;gap:8px}
.file-input .label{color:var(--muted);font-size:13px}
.file-input input{display:block;margin-top:6px}
.actions{display:flex;gap:10px}
button{background:var(--accent);color:#fff;border:none;border-radius:12px;padding:10px 16px;cursor:pointer;box-shadow:0 1px 2px rgba(0,0,0,.08)}
button:hover{filter:brightness(1.06)}
button:active{transform:translateY(1px)}
button:focus{outline:2px solid rgba(0,122,255,.35);outline-offset:2px}
button[disabled]{opacity:.6;cursor:not-allowed}
.primary{font-weight:600}
.segmented{display:inline-flex;align-items:center;border:1px solid var(--border);border-radius:12px;overflow:hidden;background:#fff}
.segmented input{position:absolute;opacity:0;pointer-events:none}
.segmented label{padding:8px 14px;font-size:14px;color:var(--text);cursor:pointer}
.segmented label:first-of-type{border-right:1px solid var(--border)}
.segmented input:checked+label{background:#f0f2f5;color:#000}
.status{min-height:20px;color:var(--muted)}
.preview{background:var(--panel);padding:16px;border:1px solid var(--border);border-radius:14px;display:flex;align-items:center;justify-content:center;box-shadow:0 1px 3px rgba(0,0,0,.06)}
#previewCanvas{width:540px;height:540px;border-radius:12px;border:1px solid var(--border);background:#fff}
.tiles{display:grid;grid-template-columns:repeat(3, 1fr);gap:12px}
.tile{background:var(--panel);border:1px solid var(--border);border-radius:14px;padding:10px;display:flex;flex-direction:column;gap:6px;box-shadow:0 1px 3px rgba(0,0,0,.06)}
.tile img{width:100%;height:auto;border-radius:6px}
.tile .meta{color:var(--muted);font-size:12px}
@media (max-width:900px){.container{grid-template-columns:1fr}#previewCanvas{width:420px;height:420px}}