:root {
  --bg: #f6f7f9;
  --surface: #ffffff;
  --text: #14171c;
  --muted: #5b6573;
  --line: #e2e6ec;
  --accent: #3b5bfd;
  --accent-ink: #ffffff;
  --accent-soft: #e9edff;
  --danger: #b3261e;
  --radius: 12px;
}
@media (prefers-color-scheme: dark) {
  :root {
    --bg: #0e1116;
    --surface: #161b22;
    --text: #e8ebf0;
    --muted: #98a2b1;
    --line: #262d38;
    --accent: #6b86ff;
    --accent-ink: #0b0f1a;
    --accent-soft: #1b2340;
    --danger: #ff8a80;
  }
}
* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font: 16px/1.6 system-ui, -apple-system, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
}
a { color: var(--accent); text-decoration: none; }
a:hover { text-decoration: underline; }
.wrap { max-width: 1040px; margin: 0 auto; padding: 0 20px; }

/* header */
.site-header { border-bottom: 1px solid var(--line); background: var(--surface); }
.site-header .wrap { display: flex; align-items: center; justify-content: space-between; height: 64px; }
.brand { display: flex; align-items: center; gap: 10px; color: var(--text); font-weight: 700; font-size: 18px; letter-spacing: -0.01em; }
.brand:hover { text-decoration: none; }
.brand svg { width: 28px; height: 28px; }
.nav { display: flex; align-items: center; gap: 22px; }
.nav a { color: var(--muted); font-size: 15px; }
.nav a:hover { color: var(--text); text-decoration: none; }

/* buttons */
.btn {
  display: inline-flex; align-items: center; justify-content: center;
  padding: 10px 18px; border-radius: 10px; border: 1px solid var(--line);
  background: var(--surface); color: var(--text); font: inherit; font-weight: 600; cursor: pointer;
}
.btn:hover { text-decoration: none; border-color: var(--muted); }
.btn.primary { background: var(--accent); border-color: var(--accent); color: var(--accent-ink); }
.btn.primary:hover { filter: brightness(1.06); }
.btn[disabled] { opacity: .6; cursor: default; }

/* hero */
.hero { padding: 84px 0 56px; text-align: center; }
.pill {
  display: inline-block; padding: 4px 12px; border-radius: 999px;
  background: var(--accent-soft); color: var(--accent); font-size: 13px; font-weight: 600;
}
.hero h1 { font-size: clamp(34px, 6vw, 56px); line-height: 1.1; letter-spacing: -0.03em; margin: 18px auto 14px; max-width: 760px; }
.hero p { color: var(--muted); font-size: 18px; max-width: 580px; margin: 0 auto 28px; }
.hero .actions { display: flex; gap: 12px; justify-content: center; flex-wrap: wrap; }

/* sections */
section { padding: 40px 0; }
h2 { font-size: 26px; letter-spacing: -0.02em; margin: 0 0 8px; }
.lead { color: var(--muted); margin: 0 0 28px; }
.grid { display: grid; gap: 16px; grid-template-columns: repeat(auto-fit, minmax(260px, 1fr)); }
.card { background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius); padding: 22px; }
.card h3 { margin: 0 0 6px; font-size: 17px; }
.card p { margin: 0; color: var(--muted); font-size: 15px; }
.ico { width: 36px; height: 36px; border-radius: 10px; background: var(--accent-soft); color: var(--accent); display: grid; place-items: center; margin-bottom: 14px; font-weight: 700; }

.formats { display: flex; flex-wrap: wrap; gap: 8px; }
.formats span { padding: 6px 12px; border: 1px solid var(--line); background: var(--surface); border-radius: 8px; font-size: 14px; font-variant-numeric: tabular-nums; }

.steps { counter-reset: s; display: grid; gap: 16px; grid-template-columns: repeat(auto-fit, minmax(240px, 1fr)); }
.step { position: relative; padding-left: 46px; }
.step::before {
  counter-increment: s; content: counter(s);
  position: absolute; left: 0; top: 0; width: 32px; height: 32px; border-radius: 50%;
  background: var(--accent); color: var(--accent-ink); display: grid; place-items: center; font-weight: 700;
}
.step h3 { margin: 0 0 4px; font-size: 17px; }
.step p { margin: 0; color: var(--muted); font-size: 15px; }

.notice { background: var(--accent-soft); border-radius: var(--radius); padding: 22px; text-align: center; }
.notice p { margin: 0 0 14px; }

/* auth */
.auth { min-height: calc(100vh - 64px - 90px); display: grid; place-items: center; padding: 40px 20px; }
.auth-box { width: 100%; max-width: 400px; background: var(--surface); border: 1px solid var(--line); border-radius: 16px; padding: 30px; }
.auth-box h1 { font-size: 24px; margin: 0 0 6px; letter-spacing: -0.02em; }
.auth-box .sub { color: var(--muted); margin: 0 0 22px; font-size: 15px; }
label { display: block; font-size: 14px; font-weight: 600; margin: 14px 0 6px; }
input[type=email], input[type=password], input[type=text] {
  width: 100%; padding: 11px 12px; font: inherit; color: var(--text); background: var(--bg);
  border: 1px solid var(--line); border-radius: 10px;
}
input:focus { outline: 2px solid var(--accent); outline-offset: 1px; border-color: transparent; }
.auth-box .btn { width: 100%; margin-top: 20px; }
.error { color: var(--danger); font-size: 14px; margin: 14px 0 0; min-height: 20px; }
.alt { text-align: center; color: var(--muted); font-size: 14px; margin: 18px 0 0; }

/* text pages */
.doc { padding: 56px 0; max-width: 720px; }
.doc h1 { font-size: 34px; letter-spacing: -0.02em; margin: 0 0 6px; }
.doc .meta { color: var(--muted); margin: 0 0 28px; }
.doc h2 { font-size: 20px; margin: 28px 0 6px; }
.doc p { margin: 0 0 12px; }

/* footer */
.site-footer { border-top: 1px solid var(--line); padding: 26px 0; color: var(--muted); font-size: 14px; }
.site-footer .wrap { display: flex; justify-content: space-between; flex-wrap: wrap; gap: 10px; }
.site-footer nav { display: flex; gap: 18px; }
.site-footer a { color: var(--muted); }

@media (max-width: 560px) {
  .nav .hide-sm { display: none; }
  .nav { gap: 14px; }
  .hero { padding-top: 56px; }
}