:root{--sky:#0ea5e9;--sky-dark:#0284c7;--ink:#1f2937;--mut:#6b7280;--line:#e5e7eb}
*{margin:0;padding:0;box-sizing:border-box}
body{font-family:-apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,Inter,Arial,sans-serif;color:var(--ink);background:#fff;line-height:1.6}
a{color:var(--sky-dark);text-decoration:none}
header.site{background:#fff;border-bottom:1px solid var(--line);padding:16px 22px;display:flex;align-items:center;gap:10px;max-width:1100px;margin:0 auto}
header.site .logo{font-weight:800;font-size:22px;color:var(--ink);letter-spacing:-.3px}
header.site .logo span{color:var(--sky)}
header.site nav{margin-left:auto;display:flex;gap:18px;font-size:14px}
header.site nav a{color:var(--mut)}
.hero{text-align:center;padding:38px 20px 2px;max-width:720px;margin:0 auto}
.hero h1{font-size:30px;font-weight:700;color:#111827;line-height:1.25}
.hero p{color:var(--mut);margin-top:12px;font-size:16px}
.grid{max-width:1000px;margin:30px auto;padding:0 14px;display:grid;grid-template-columns:repeat(auto-fill,minmax(150px,1fr));gap:10px}
.tool{display:block;background:#fff;border:1px solid var(--line);border-radius:10px;padding:14px;color:var(--ink)}
.tool:hover{border-color:var(--sky);box-shadow:0 6px 20px rgba(14,165,233,.10)}
.tool .ic{font-size:24px}
.tool h3{font-size:14px;margin:6px 0 3px;color:#111827}
.tool p{font-size:12px;color:var(--mut);line-height:1.45}
.wrap{max-width:680px;margin:0 auto;padding:48px 16px 10px;text-align:center}
.wrap h1{font-size:32px;font-weight:700;color:#111827}
.wrap .desc{color:var(--mut);margin:12px auto 30px;font-size:16px;max-width:520px}
.drop{background:var(--sky);border:none;border-radius:14px;padding:40px 18px;text-align:center;cursor:pointer;color:#fff;box-shadow:0 8px 24px rgba(14,165,233,.35);max-width:480px;margin:0 auto}
.drop:hover{background:var(--sky-dark)}
.drop input{display:none}
.drop .big{font-size:22px;font-weight:700}
.drop .small{font-size:13px;color:#e0f2fe;margin-top:4px}
.filelist{margin:16px auto 0;font-size:14px;list-style:none;max-width:480px;text-align:left}
.filelist li{margin:3px 0}
.opt{margin:18px auto 0;display:flex;gap:10px;align-items:center;justify-content:center;flex-wrap:wrap;max-width:480px}
.opt input[type=text]{padding:9px 12px;border:1px solid var(--line);border-radius:9px;font-size:15px}
.opt select{padding:9px;border:1px solid var(--line);border-radius:9px;font-size:15px}
.btn{background:var(--sky);color:#fff;border:none;padding:14px 26px;border-radius:12px;font-size:16px;font-weight:700;cursor:pointer;width:100%;max-width:480px;margin:18px auto 0;display:block}
.btn:hover{background:var(--sky-dark)}
.btn:disabled{background:#94a3b8;cursor:wait}
.msg{margin-top:14px;font-size:14px;text-align:center}
.msg.err{color:#dc2626}.msg.ok{color:#059669}
.note{max-width:720px;margin:8px auto 30px;padding:0 16px;font-size:13px;color:var(--mut);text-align:center}
footer.site{text-align:center;color:#9ca3af;font-size:13px;padding:40px 16px}
.ed-toolbar{display:flex;gap:8px;flex-wrap:wrap;margin:14px 0}
.ed-toolbar button{padding:8px 14px;border:1px solid var(--line);background:#fff;border-radius:9px;cursor:pointer;font-size:14px}
.ed-toolbar button.active{background:var(--sky);color:#fff;border-color:var(--sky)}
.ed-stage{position:relative;border:1px solid var(--line);border-radius:10px;overflow:hidden;background:#fff;text-align:left}
.ed-stage img{width:100%;display:block}
.ed-stage .marker{position:absolute;background:rgba(14,165,233,.15);border:1px solid var(--sky);font-size:12px;padding:1px 4px;color:var(--ink)}
.ed-stage .hl{position:absolute;background:rgba(250,204,21,.45)}
.pager{display:flex;gap:10px;align-items:center;justify-content:center;margin:10px 0}
#sigpad{border:1px solid var(--line);border-radius:8px;background:#fff;touch-action:none}
#editor{text-align:left}