:root {
  --bg: #f6f5f1;
  --surface: #ffffff;
  --text: #1c1b18;
  --muted: #65625a;
  --line: #e3e0d7;
  --accent: #2f5bea;
  --accent-text: #ffffff;
  --accent-soft: #e8eefe;
  --ok: #1d7a46;
  --ok-soft: #e3f4ea;
  --warn: #8a5a00;
  --warn-soft: #fdf1d8;
  --error: #b42318;
  --error-soft: #fde8e6;
  --mock-bar: #eceae4;
  --radius: 14px;
  color-scheme: light;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #15161a;
    --surface: #1f2026;
    --text: #ecebe6;
    --muted: #a3a19a;
    --line: #34353d;
    --accent: #7c9bff;
    --accent-text: #0e1020;
    --accent-soft: #232b48;
    --ok: #6fd39a;
    --ok-soft: #173325;
    --warn: #f1c26b;
    --warn-soft: #3a2f17;
    --error: #ff8a80;
    --error-soft: #3d1d1b;
    --mock-bar: #2a2b31;
    color-scheme: dark;
  }
}

* { box-sizing: border-box; }

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font: 18px/1.6 system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
}

a { color: var(--accent); }
code { font-family: ui-monospace, SFMono-Regular, Menlo, monospace; font-size: 0.9em; }

.top, main, .bottom { max-width: 760px; margin: 0 auto; padding: 0 16px; }
.top { display: flex; justify-content: space-between; align-items: center; gap: 12px; padding-top: 20px; flex-wrap: wrap; }
.top nav { display: flex; gap: 16px; }
.logo { font-weight: 700; color: var(--text); text-decoration: none; }
.bottom { color: var(--muted); font-size: 15px; padding-top: 24px; padding-bottom: 40px; }

h1 { font-size: 30px; line-height: 1.25; margin: 0 0 12px; }
h2 { font-size: 22px; margin: 0 0 12px; }
h3 { font-size: 18px; margin: 20px 0 4px; }
.code { background: var(--bg); border: 1px solid var(--line); border-radius: 10px; padding: 14px; overflow-x: auto; font-size: 14px; line-height: 1.5; }
.lead { font-size: 20px; color: var(--muted); }
.muted { color: var(--muted); font-size: 16px; }

.hero { padding: 36px 0 12px; }
.card {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 24px;
  margin: 16px 0;
}

.checks { padding-left: 0; list-style: none; }
.checks li { padding-left: 30px; position: relative; margin: 10px 0; }
.checks li::before { content: "•"; position: absolute; left: 10px; color: var(--accent); font-weight: 700; }

.big-steps { counter-reset: step; list-style: none; padding: 0; }
.big-steps li { counter-increment: step; display: flex; flex-direction: column; padding: 10px 0 10px 52px; position: relative; }
.big-steps li::before {
  content: counter(step);
  position: absolute; left: 0; top: 8px;
  width: 36px; height: 36px; border-radius: 50%;
  background: var(--accent-soft); color: var(--accent);
  display: grid; place-items: center; font-weight: 700;
}

.pairs dt { margin-top: 12px; font-weight: 600; }
.pairs dd { margin: 4px 0 0; color: var(--muted); }

.prices { width: 100%; border-collapse: collapse; font-size: 16px; }
.prices th, .prices td { text-align: left; padding: 8px; border-bottom: 1px solid var(--line); }

.progress { display: flex; gap: 8px; list-style: none; padding: 0; margin: 0 0 24px; flex-wrap: wrap; }
.progress li { display: flex; align-items: center; gap: 8px; color: var(--muted); font-size: 15px; }
.progress .dot {
  width: 30px; height: 30px; border-radius: 50%; display: grid; place-items: center;
  border: 2px solid var(--line); font-weight: 700;
}
.progress li.done .dot { background: var(--ok-soft); border-color: var(--ok); color: var(--ok); }
.progress li.current { color: var(--text); font-weight: 600; }
.progress li.current .dot { background: var(--accent); border-color: var(--accent); color: var(--accent-text); }
@media (max-width: 560px) { .progress li:not(.current) .label { display: none; } }

.notice { border-radius: 10px; padding: 14px 16px; margin: 16px 0; }
.notice p { margin: 6px 0 0; }
.notice h1 { margin-bottom: 6px; }
.notice-info { background: var(--accent-soft); }
.notice-warn { background: var(--warn-soft); color: var(--warn); }
.notice-error { background: var(--error-soft); color: var(--error); }

.stack { display: flex; flex-direction: column; gap: 14px; margin-top: 20px; }
.agree, .choice {
  display: flex; gap: 12px; align-items: flex-start;
  border: 2px solid var(--line); border-radius: 10px; padding: 14px; cursor: pointer;
}
.agree input, .choice input { width: 22px; height: 22px; margin-top: 3px; flex: none; }
.choice:has(input:checked), .agree:has(input:checked) { border-color: var(--accent); background: var(--accent-soft); }

textarea {
  width: 100%; font: 16px/1.4 ui-monospace, Menlo, monospace; padding: 12px;
  border-radius: 10px; border: 2px solid var(--line); background: var(--bg); color: var(--text);
}
textarea:focus { outline: none; border-color: var(--accent); }
.field-hint { margin: -6px 0 0; font-size: 15px; min-height: 1.4em; }
.field-hint.ok { color: var(--ok); }
.field-hint.bad { color: var(--error); }

.btn {
  font: inherit; font-weight: 600; border-radius: 10px; padding: 12px 20px;
  border: 2px solid transparent; cursor: pointer; text-align: center;
}
.btn-primary { background: var(--accent); color: var(--accent-text); }
.btn-primary:hover { filter: brightness(1.08); }
.btn-big { font-size: 21px; padding: 18px 24px; }
.btn-ghost { background: transparent; color: var(--muted); border-color: var(--line); }
.back { margin-top: 24px; }

.browser-mock { margin: 20px 0; border: 1px solid var(--line); border-radius: 12px; overflow: hidden; }
.browser-bar { background: var(--mock-bar); padding: 10px 12px; display: flex; gap: 12px; align-items: center; }
.lights { display: flex; gap: 6px; }
.lights i { width: 11px; height: 11px; border-radius: 50%; background: var(--line); display: block; }
.address {
  flex: 1; min-width: 0; background: var(--surface); border-radius: 8px; padding: 6px 10px;
  display: flex; align-items: center; gap: 10px; font: 14px ui-monospace, Menlo, monospace;
  outline: 3px solid var(--accent); outline-offset: 1px;
}
.address-text { background: var(--accent-soft); overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.pointer { margin-left: auto; white-space: nowrap; font-family: system-ui, sans-serif; color: var(--accent); font-weight: 600; }
.browser-body { padding: 28px 20px; background: var(--surface); }
.sad { font-size: 34px; color: var(--muted); }
.err-title { font-size: 22px; font-weight: 600; margin: 6px 0 0; }
.err-sub { color: var(--muted); margin: 4px 0 0; }
.browser-mock figcaption { padding: 10px 14px; font-size: 15px; color: var(--muted); border-top: 1px solid var(--line); }
@media (max-width: 560px) { .pointer { display: none; } }

.done-mark {
  width: 64px; height: 64px; border-radius: 50%; background: var(--ok-soft); color: var(--ok);
  display: grid; place-items: center; font-size: 34px; font-weight: 700; margin-bottom: 12px;
}