:root{
  --bg:#f8fafc; --card:#ffffff; --ink:#0f172a; --muted:#64748b; --line:#e2e8f0;
  --blue:#2563eb; --blue-600:#1d4ed8; --green:#22c55e; --soft:#eff6ff;
  --grad:linear-gradient(90deg,#3b82f6,#22c55e);
  --shadow:0 10px 30px rgba(15,23,42,.08); --shadow-lg:0 20px 50px rgba(15,23,42,.12);
  --r:16px;
}
*{box-sizing:border-box}
html,body{margin:0;padding:0}
body{font-family:'Inter',-apple-system,BlinkMacSystemFont,'Segoe UI',Arial,sans-serif;background:var(--bg);color:var(--ink);-webkit-font-smoothing:antialiased;line-height:1.5}
a{color:inherit;text-decoration:none}
button{font-family:inherit;cursor:pointer;border:none;background:none}
input{font-family:inherit;font-size:15px}

/* top nav */
.top{position:sticky;top:0;z-index:20;background:rgba(248,250,252,.85);backdrop-filter:blur(10px);border-bottom:1px solid var(--line)}
.top-in{max-width:1040px;margin:0 auto;padding:14px 24px;display:flex;align-items:center;justify-content:space-between}
.top-mid .top-in{justify-content:center}
.brand{display:inline-flex;align-items:center;gap:9px;font-weight:800;font-size:19px;color:var(--ink)}
.brand span{letter-spacing:-.02em}
.nav{display:flex;align-items:center;gap:22px;font-size:14.5px;font-weight:500;color:var(--muted)}
.nav a:hover{color:var(--ink)}

/* buttons */
.btn{background:var(--blue);color:#fff;font-weight:600;font-size:15px;padding:12px 22px;border-radius:11px;transition:.15s;box-shadow:0 1px 2px rgba(37,99,235,.3)}
.btn:hover{background:var(--blue-600)}
.btn:disabled{opacity:.6;cursor:default}
.btn-ghost{color:var(--blue);font-weight:600;font-size:14.5px;padding:9px 16px;border-radius:10px;background:var(--soft);transition:.15s}
.btn-ghost:hover{background:#dbeafe}

/* hero */
.hero{max-width:720px;margin:0 auto;padding:56px 24px 8px;text-align:center}
.hero h1{font-size:46px;line-height:1.08;letter-spacing:-.03em;margin:0 0 14px;font-weight:800}
.grad{background:var(--grad);-webkit-background-clip:text;background-clip:text;-webkit-text-fill-color:transparent}
.sub{font-size:18px;color:var(--muted);max-width:520px;margin:0 auto 32px}

/* dropzone */
.drop{border:2px dashed var(--line);border-radius:var(--r);background:var(--card);padding:44px 24px;text-align:center;transition:.15s;box-shadow:var(--shadow)}
.drop.over{border-color:var(--blue);background:var(--soft)}
.drop-inner{display:flex;flex-direction:column;align-items:center;gap:6px}
.drop-title{font-weight:600;font-size:17px;margin:10px 0 2px}
.drop-sub{color:var(--muted);font-size:14px}
.drop-cap{color:var(--muted);font-size:13px;margin-top:14px}

/* done card */
.done{max-width:520px;margin:26px auto 0}
.done-card{background:var(--card);border:1px solid var(--line);border-radius:var(--r);box-shadow:var(--shadow-lg);padding:28px;text-align:left}
.done-ico{width:48px;height:48px;border-radius:50%;background:#dcfce7;color:#16a34a;display:grid;place-items:center;font-size:24px;font-weight:800;margin-bottom:12px}
.done-card h3{margin:0 0 4px;font-size:20px}
.fname{color:var(--muted);font-size:14px;margin-bottom:18px}
.fname em{color:#94a3b8;font-style:normal}
.lbl{display:block;font-size:12.5px;font-weight:600;color:var(--muted);text-transform:uppercase;letter-spacing:.03em;margin:14px 0 6px}
.linkrow{display:flex;gap:8px}
.linkrow input{flex:1;padding:11px 12px;border:1px solid var(--line);border-radius:10px;background:#f8fafc;color:var(--ink)}
.linkrow .btn-ghost,.linkrow .btn{white-space:nowrap}
.shareby{margin-top:16px}
.tiny{color:#94a3b8;font-size:12.5px;margin:16px 0 0}
.status{font-size:13.5px;margin:10px 0 0;min-height:18px}
.status.ok{color:#16a34a}.status.err{color:#dc2626}

/* how */
.how,.feat,.faq{max-width:1040px;margin:0 auto;padding:56px 24px}
.how h2,.faq h2{text-align:center;font-size:30px;letter-spacing:-.02em;margin:0 0 30px}
.steps{display:grid;grid-template-columns:repeat(3,1fr);gap:20px}
.step{background:var(--card);border:1px solid var(--line);border-radius:var(--r);padding:26px}
.step .n{width:34px;height:34px;border-radius:50%;background:var(--grad);color:#fff;display:grid;place-items:center;font-weight:800;margin-bottom:14px}
.step h4{margin:0 0 6px;font-size:17px}
.step p{margin:0;color:var(--muted);font-size:14.5px}

.feat{display:grid;grid-template-columns:repeat(4,1fr);gap:18px}
.feat .f{background:var(--card);border:1px solid var(--line);border-radius:var(--r);padding:22px}
.fi{font-size:26px;margin-bottom:10px}
.f h4{margin:0 0 4px;font-size:16px}
.f p{margin:0;color:var(--muted);font-size:14px}

/* faq */
.faq details{background:var(--card);border:1px solid var(--line);border-radius:12px;padding:16px 18px;margin-bottom:10px}
.faq summary{font-weight:600;cursor:pointer;list-style:none;display:flex;justify-content:space-between}
.faq summary::-webkit-details-marker{display:none}
.faq summary::after{content:'+';color:var(--muted);font-weight:700}
.faq details[open] summary::after{content:'–'}
.faq p{color:var(--muted);margin:10px 0 0;font-size:14.5px}

/* file card page */
.fc-main{max-width:520px;margin:0 auto;padding:44px 24px 60px}
.fc-card{background:var(--card);border:1px solid var(--line);border-radius:20px;box-shadow:var(--shadow-lg);padding:30px 28px}
.fc-hi{display:flex;align-items:center;gap:10px;font-weight:700;font-size:18px;letter-spacing:-.01em;margin-bottom:22px}
.fc-hi-ico{width:30px;height:30px;border-radius:50%;background:#dcfce7;color:#16a34a;display:grid;place-items:center;font-size:15px;font-weight:800}
.fc-preview{display:flex;justify-content:center;margin:0 0 22px}
.fc-preview-img{width:100%;max-width:290px;height:auto;border-radius:10px;border:1px solid var(--line);box-shadow:0 12px 34px rgba(15,23,42,.16);background:#fff}
.fc-div{display:flex;align-items:center;gap:12px;color:#94a3b8;font-size:12.5px;text-transform:uppercase;letter-spacing:.04em;margin:22px 0}
.fc-div::before,.fc-div::after{content:'';flex:1;height:1px;background:var(--line)}
.fc-ready{display:inline-flex;align-items:center;gap:8px;font-size:13px;font-weight:600;color:#16a34a;background:#f0fdf4;padding:6px 12px;border-radius:20px;margin-bottom:22px}
.fc-ready .dot{width:8px;height:8px;border-radius:50%;background:var(--green);box-shadow:0 0 0 4px rgba(34,197,94,.15)}
.fc-file{display:flex;align-items:center;gap:16px;padding:18px;border:1px solid var(--line);border-radius:14px;margin-bottom:22px}
.fc-file-ico{font-size:38px}
.fc-name{font-weight:700;font-size:17px;word-break:break-word}
.fc-size{color:var(--muted);font-size:13.5px;margin-top:2px}
.dl{display:flex;align-items:center;justify-content:center;gap:10px;width:100%;background:var(--blue);color:#fff;font-weight:700;font-size:17px;padding:16px;border-radius:13px;transition:.15s;box-shadow:0 4px 14px rgba(37,99,235,.3)}
.dl:hover{background:var(--blue-600)}
.fc-share{margin-top:22px;padding-top:22px;border-top:1px solid var(--line)}
.fc-foot{display:flex;align-items:center;justify-content:center;gap:12px;color:#94a3b8;font-size:13px;margin-top:22px}
.fc-foot .sep{width:4px;height:4px;border-radius:50%;background:#cbd5e1}
.fc-err{text-align:center;padding:20px 0}
.fc-err-ico{font-size:44px;margin-bottom:10px}
.fc-err h2{margin:0 0 6px;font-size:22px}
.fc-err p{color:var(--muted);margin:0 0 20px}

/* legal / doc pages */
.doc-main,.page{max-width:760px;margin:0 auto;padding:48px 24px 20px}
.doc-main h1,.page h1{font-size:34px;letter-spacing:-.02em;margin:0 0 6px}
.doc-main h2,.page h2{font-size:19px;margin:30px 0 8px;letter-spacing:-.01em}
.doc-main p,.page p{color:#334155;font-size:15.5px;line-height:1.65;margin:0 0 14px}
.doc-main h2:first-of-type,.page h2:first-of-type{margin-top:22px}
.updated,.upd{color:#94a3b8;font-size:13.5px;margin:0 0 26px}

/* footer */
.foot{border-top:1px solid var(--line);margin-top:40px}
.foot-in{max-width:1040px;margin:0 auto;padding:24px;display:flex;align-items:center;justify-content:space-between;color:var(--muted);font-size:14px}
.foot-links{display:flex;gap:20px}
.foot-links a:hover{color:var(--ink)}

@media(max-width:820px){.feat{grid-template-columns:repeat(2,1fr)}.steps{grid-template-columns:1fr}.hero h1{font-size:36px}}
@media(max-width:520px){.feat{grid-template-columns:1fr}.hero{padding-top:36px}.hero h1{font-size:31px}.nav a:not(.btn-ghost){display:none}.top-in{padding:12px 16px}}