:root {
  --bg: #fbfbfa;
  --surface: #ffffff;
  --text: #16181d;
  --muted: #6b7079;
  --faint: #9aa0a8;
  --line: #e7e7e3;
  --accent: #3b3fd8;
  --accent-soft: #eef0ff;
  --good: #1f8a5b;
  --bad: #c2412d;
  --warn-bg: #fff6e8;
  --warn-text: #8a5a12;
  --radius: 14px;
  --shadow: 0 1px 2px rgba(16, 18, 24, 0.04), 0 8px 24px rgba(16, 18, 24, 0.05);
  --font: -apple-system, BlinkMacSystemFont, "SF Pro Text", "Inter", "Segoe UI",
    "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  --mono: ui-monospace, "SF Mono", "JetBrains Mono", Menlo, Consolas, monospace;
}
@media (prefers-color-scheme: dark) {
  :root {
    --bg: #0e0f12;
    --surface: #16181d;
    --text: #ececef;
    --muted: #9aa0aa;
    --faint: #6c717b;
    --line: #262930;
    --accent: #8e93ff;
    --accent-soft: #1d1f3a;
    --good: #45c08a;
    --bad: #f07a63;
    --warn-bg: #2b2213;
    --warn-text: #f2c27a;
    --shadow: none;
  }
}
* { box-sizing: border-box; }
html, body { margin: 0; padding: 0; }
body {
  background: var(--bg); color: var(--text); font-family: var(--font);
  font-size: 16px; line-height: 1.6; -webkit-font-smoothing: antialiased;
}
a { color: var(--accent); text-decoration: none; }
.wrap { max-width: 720px; margin: 0 auto; padding: 0 20px; }
nav.top { display: flex; align-items: center; justify-content: space-between; padding: 18px 0; }
.brand { font-weight: 650; letter-spacing: -0.01em; color: var(--text); }
.brand span { color: var(--faint); font-weight: 450; margin-left: 8px; font-size: 13px; }
.nav-link { font-size: 14px; color: var(--muted); }
.hero { padding: 48px 0 32px; }
.eyebrow { font-size: 13px; color: var(--accent); font-weight: 600; letter-spacing: 0.02em; }
h1 { font-size: 34px; line-height: 1.2; letter-spacing: -0.025em; margin: 12px 0 16px;
  font-weight: 680; }
h2 { font-size: 22px; letter-spacing: -0.015em; margin: 0 0 8px; font-weight: 650; }
h3 { font-size: 17px; margin: 0 0 6px; font-weight: 620; }
.lead { color: var(--muted); font-size: 17px; margin: 0 0 28px; }
.btn {
  display: inline-flex; align-items: center; justify-content: center; gap: 8px;
  border: 0; border-radius: 12px; padding: 14px 20px; font: inherit; font-weight: 600;
  background: var(--text); color: var(--bg); cursor: pointer; width: 100%;
}
.btn.secondary { background: var(--surface); color: var(--text); border: 1px solid var(--line); }
.btn.ghost { background: transparent; color: var(--accent); padding: 10px 0; width: auto; }
.btn:disabled { opacity: 0.5; cursor: default; }
.fine { font-size: 13px; color: var(--faint); margin-top: 12px; text-align: center; }
.section { padding: 28px 0; border-top: 1px solid var(--line); }
.card {
  background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius);
  padding: 20px; box-shadow: var(--shadow); margin: 14px 0;
}
.tag { display: inline-block; font-size: 12px; font-weight: 600; padding: 3px 9px;
  border-radius: 999px; background: var(--accent-soft); color: var(--accent); }
.tag.bad { background: rgba(194, 65, 45, 0.1); color: var(--bad); }
.tag.good { background: rgba(31, 138, 91, 0.1); color: var(--good); }
.tag.muted { background: transparent; border: 1px solid var(--line); color: var(--muted); }
.kpis { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 10px; margin: 14px 0; }
.kpi { border: 1px solid var(--line); border-radius: 12px; padding: 12px; }
.kpi b { display: block; font-size: 20px; font-family: var(--mono); letter-spacing: -0.02em; }
.kpi small { color: var(--muted); font-size: 12px; }
.neg { color: var(--bad); }
.pos { color: var(--good); }
.rule { border-left: 3px solid var(--accent); padding: 4px 0 4px 14px; margin: 14px 0;
  font-weight: 600; }
.foot-note { font-size: 12px; color: var(--faint); font-family: var(--mono); margin-top: 10px; }
.checks { list-style: none; padding: 0; margin: 12px 0; }
.checks li { padding: 6px 0; display: flex; gap: 10px; align-items: baseline; }
.checks .y { color: var(--good); font-weight: 700; }
.checks .n { color: var(--bad); font-weight: 700; }
.steps { display: grid; gap: 10px; counter-reset: s; }
.step { display: flex; gap: 14px; align-items: flex-start; border: 1px solid var(--line);
  border-radius: 12px; padding: 12px 14px; background: var(--surface); }
.step::before { counter-increment: s; content: counter(s); flex: 0 0 26px; height: 26px;
  border-radius: 50%; background: var(--accent-soft); color: var(--accent); font-weight: 700;
  font-size: 13px; display: flex; align-items: center; justify-content: center; }
label { display: block; font-size: 14px; color: var(--muted); margin: 14px 0 6px; }
input[type=text], input[type=password], input[type=email] {
  width: 100%; padding: 13px 14px; border: 1px solid var(--line); border-radius: 10px;
  font: inherit; font-family: var(--mono); font-size: 15px; background: var(--surface);
  color: var(--text);
}
.check { display: flex; gap: 10px; align-items: flex-start; font-size: 14px; color: var(--muted);
  margin: 16px 0; }
.alert { background: var(--warn-bg); color: var(--warn-text); border-radius: 12px; padding: 12px 14px;
  font-size: 14px; margin: 12px 0; }
.alert.error { background: rgba(194, 65, 45, 0.1); color: var(--bad); }
.hidden { display: none !important; }
.progress { height: 6px; border-radius: 99px; background: var(--line); overflow: hidden; margin: 14px 0; }
.progress > div { height: 100%; width: 10%; background: var(--accent); transition: width 0.6s ease; }
.fact { padding: 12px 0; border-bottom: 1px solid var(--line); }
.fact:last-child { border-bottom: 0; }
details summary { cursor: pointer; color: var(--accent); font-size: 14px; margin-top: 10px; }
table.ev { width: 100%; border-collapse: collapse; font-size: 14px; margin-top: 10px; }
table.ev td { padding: 6px 0; border-bottom: 1px solid var(--line); }
table.ev td:last-child { text-align: right; font-family: var(--mono); }
canvas { width: 100%; height: 260px; display: block; border-radius: 10px; background: var(--bg); }
.seg { display: inline-flex; border: 1px solid var(--line); border-radius: 10px; overflow: hidden;
  margin-top: 10px; }
.seg button { border: 0; background: transparent; padding: 8px 14px; font: inherit; font-size: 14px;
  color: var(--muted); cursor: pointer; }
.seg button.on { background: var(--text); color: var(--bg); }
.prices { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 8px; margin: 12px 0; }
.prices button { border: 1px solid var(--line); background: var(--surface); color: var(--text);
  border-radius: 10px; padding: 12px; font: inherit; cursor: pointer; }
.prices button.on { border-color: var(--accent); color: var(--accent); }
.modal { position: fixed; inset: 0; background: rgba(10, 10, 14, 0.45); display: flex;
  align-items: flex-end; justify-content: center; z-index: 10; }
.modal .sheet { background: var(--surface); width: 100%; max-width: 520px; border-radius: 18px 18px 0 0;
  padding: 22px 20px 28px; }
.badge-ok { font-size: 13px; color: var(--good); }
.demo-banner { background: var(--accent-soft); color: var(--accent); font-size: 13px; padding: 10px 14px;
  border-radius: 10px; margin: 8px 0 0; }
footer { padding: 40px 0 60px; color: var(--faint); font-size: 13px; }
@media (min-width: 720px) {
  h1 { font-size: 44px; }
  .btn { width: auto; }
  .kpis { grid-template-columns: repeat(4, minmax(0, 1fr)); }
}

/* nav: brand left, language switch right (fits 375px with English) */
nav.top { gap: 12px; }
.brand { display: flex; align-items: baseline; flex-wrap: wrap; gap: 0 8px; min-width: 0; }
.brand span { margin-left: 0; }
.nav-right { display: flex; align-items: center; gap: 14px; flex-shrink: 0; }
.lang { font-size: 13px; color: var(--faint); white-space: nowrap; }
.lang a { color: var(--muted); padding: 4px 2px; }
.lang a.on { color: var(--text); font-weight: 650; }
.lang i { font-style: normal; margin: 0 6px; color: var(--line); }
.principle { margin: 18px 0 0; font-size: 14px; color: var(--muted); letter-spacing: 0.01em;
  text-align: center; }
.headline { font-family: var(--mono); font-size: 22px; letter-spacing: -0.02em; margin: 2px 0 4px;
  font-weight: 600; }
.eyebrow { margin: 0; }
h1, h2, h3, .btn, .rule { overflow-wrap: anywhere; }
.kpi small { display: block; line-height: 1.35; }
.btn { text-align: center; line-height: 1.35; }