:root{color-scheme:light;--ink:#17212f;--muted:#526176;--line:#dbe2ea;--blue:#165fd3;--pale:#eef5ff;--surface:#fff;--page:#f6f8fb}
*{box-sizing:border-box}
html{font-family:system-ui,-apple-system,"Segoe UI",Arial,sans-serif;color:var(--ink);background:var(--page);line-height:1.5;-webkit-text-size-adjust:100%}
body{margin:0}
button,input,select{font:inherit}
button{cursor:pointer}
a{color:#1259c7}
.shell{width:min(1120px,100%);margin:auto;padding-inline:20px}
.site-header{background:#fff;border-bottom:1px solid var(--line)}
.header-inner{min-height:60px;display:flex;align-items:center;justify-content:space-between;gap:12px}
.brand{font-size:18px;font-weight:750;text-decoration:none;color:var(--ink)}
.header-note{font-size:13px;color:#32604b}
main{padding-bottom:60px}
h1{font-size:clamp(28px,4vw,39px);line-height:1.15;letter-spacing:-.035em;margin:27px 0 7px}
.intro{color:var(--muted);font-size:16px;margin:0 0 19px}
.tool{background:var(--surface);border:1px solid var(--line);border-radius:18px;box-shadow:0 12px 30px rgba(20,39,68,.06);overflow:hidden}
.tool-main{display:grid;grid-template-columns:1fr 1fr}
.input-panel,.settings-panel{padding:25px;min-width:0}
.input-panel{border-right:1px solid var(--line)}
h2{font-size:21px;letter-spacing:-.02em;margin:0 0 15px}
.drop-zone{min-height:160px;border:2px dashed #a9bee0;background:#f7faff;border-radius:14px;display:flex;align-items:center;justify-content:center;flex-direction:column;text-align:center;padding:18px;color:var(--muted);cursor:pointer;gap:2px}
.drop-zone strong{font-size:18px;color:#1158c9}
.drop-zone small{font-size:12px;margin-top:8px}
.drop-zone.dragging{border-color:var(--blue);background:#eaf2ff}
.drop-zone:focus-within,.drop-zone:focus-visible{outline:3px solid #8fb8ff;outline-offset:2px}
.drop-icon{border-radius:50%;width:32px;height:32px;line-height:28px;background:#e6f0ff;color:var(--blue);font-size:26px;margin-bottom:4px}
.file-input{position:absolute;width:1px;height:1px;opacity:0;overflow:hidden}
.list-head{display:flex;align-items:center;justify-content:space-between;gap:8px;margin:17px 0 8px}
.list-head strong{font-size:14px}
.text-button{border:0;background:none;color:#1259c7;padding:5px 0;text-decoration:underline}
.image-list{list-style:none;padding:0;margin:0;display:grid;gap:8px;max-height:360px;overflow:auto}
.image-list li{display:flex;align-items:center;gap:10px;padding:7px;border:1px solid var(--line);border-radius:10px;min-width:0}
.image-list img{width:48px;height:48px;object-fit:cover;border-radius:5px;background:#f0f3f7;flex:none}
.image-meta{min-width:0;flex:1}
.image-meta strong{display:block;font-size:13px;white-space:nowrap;overflow:hidden;text-overflow:ellipsis}
.image-meta span{display:block;font-size:12px;color:var(--muted)}
.item-actions{display:flex;gap:2px;flex:none}
.item-actions button{background:#fff;border:1px solid var(--line);border-radius:6px;width:29px;height:29px;color:var(--ink);line-height:1}
.item-actions button:disabled{opacity:.4;cursor:not-allowed}
.subtle{font-size:13px;color:var(--muted);margin:10px 0 0}
.fields{display:grid;gap:12px;margin-bottom:13px;align-items:end}
.fields.two{grid-template-columns:repeat(2,minmax(0,1fr))}
.fields.three{grid-template-columns:1fr 1fr 1fr}
.fields label{font-size:13px;font-weight:650;display:flex;flex-direction:column;gap:5px;min-width:0}
.fields input[type=number],.fields select{height:40px;width:100%;min-width:0;padding:6px 9px;color:var(--ink);background:#fff;border:1px solid #bac6d5;border-radius:8px}
.fields input[type=color]{width:100%;height:40px;padding:3px;border:1px solid #bac6d5;border-radius:8px;background:#fff}
.fields .check-label{display:flex;flex-direction:row;align-items:center;gap:8px;min-height:40px;padding:7px 0}
.check-label input{width:18px;height:18px;flex:none;accent-color:var(--blue)}
input:focus-visible,select:focus-visible,button:focus-visible,a:focus-visible,summary:focus-visible{outline:3px solid #8fb8ff;outline-offset:2px}
.size-readout{font-weight:700;font-size:14px;margin:7px 0}
#formatNote{margin:0 0 14px}
.primary-button{display:inline-flex;align-items:center;justify-content:center;border:0;border-radius:9px;background:var(--blue);color:#fff;text-decoration:none;font-weight:700;min-height:44px;padding:10px 20px}
.primary-button:hover:not(:disabled){background:#0d4faf}
.primary-button:disabled{opacity:.48;cursor:not-allowed}
.status{font-size:13px;color:#37516c;min-height:20px;margin:10px 0 0}
.status.error{color:#a02323}
.result{border-top:1px solid var(--line);padding:24px}
.result-heading{display:flex;justify-content:space-between;align-items:center;gap:12px;margin-bottom:15px}
.result-heading h2{margin:0}
.result-heading .subtle{margin:2px 0 0}
.preview{max-width:100%;overflow:auto;background-color:#fff;background-image:linear-gradient(45deg,#e4e8ee 25%,transparent 25%),linear-gradient(-45deg,#e4e8ee 25%,transparent 25%),linear-gradient(45deg,transparent 75%,#e4e8ee 75%),linear-gradient(-45deg,transparent 75%,#e4e8ee 75%);background-position:0 0,0 10px,10px -10px,-10px 0;background-size:20px 20px;border:1px solid var(--line);border-radius:10px;text-align:center}
.preview img{display:block;max-width:100%;height:auto;margin:auto}
.content-section{margin:34px 0 0;max-width:900px}
.content-section h2{margin-bottom:8px}
.content-section p{margin:0 0 13px;color:#374459}
.faq details{background:#fff;border:1px solid var(--line);border-radius:9px;margin:8px 0;padding:0 14px}
.faq summary{cursor:pointer;font-weight:650;padding:12px 0}
.faq details p{padding:0 0 12px;margin:0}
.site-footer{border-top:1px solid var(--line);background:#fff;color:var(--muted);font-size:13px}
.footer-inner{display:flex;justify-content:space-between;gap:12px;flex-wrap:wrap;padding-block:20px}
.footer-inner nav{display:flex;gap:16px}
@media(max-width:760px){.tool-main{grid-template-columns:1fr}.input-panel{border-right:0;border-bottom:1px solid var(--line)}.input-panel,.settings-panel{padding:18px}.header-note{font-size:11px}.result{padding:18px}}
@media(max-width:480px){.shell{padding-inline:14px}.fields.three{grid-template-columns:repeat(2,minmax(0,1fr))}.fields.three .check-label{grid-column:1/-1;min-height:26px}.fields.two{gap:9px}.result-heading{align-items:stretch;flex-direction:column}.download{width:100%}.primary-button#makeGrid{width:100%}.item-actions button{width:28px}.site-footer nav{flex-wrap:wrap}}