:root {
  --bg: #f1f4f6;
  --bg-alt: #e6ecf0;
  --surface: #ffffff;
  --ink: #15242f;
  --muted: #51636f;
  --line: #cfd9df;
  --accent: #1f6f8b;
  --accent-ink: #ffffff;
  --ok: #2f9e6b;
  --warn: #e0a526;
  --bad: #d4483b;
  --font: system-ui, -apple-system, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  --mono: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #0f1a21;
    --bg-alt: #14232c;
    --surface: #182b36;
    --ink: #e7eef2;
    --muted: #9db0bb;
    --line: #28404d;
    --accent: #4fb0d0;
    --accent-ink: #082029;
  }
}

*, *::before, *::after { box-sizing: border-box; }

html { scroll-behavior: smooth; scroll-padding-top: 4.5rem; }

body {
  margin: 0;
  font-family: var(--font);
  font-size: 1.0625rem;
  line-height: 1.6;
  color: var(--ink);
  background: var(--bg);
}

.wrap { width: min(72rem, 100% - 2.5rem); margin-inline: auto; }
.narrow { width: min(44rem, 100% - 2.5rem); }

a { color: var(--accent); }
:focus-visible { outline: 3px solid var(--accent); outline-offset: 3px; border-radius: 4px; }

/* Шапка */
.top {
  position: sticky; top: 0; z-index: 10;
  background: var(--bg);
  border-bottom: 1px solid var(--line);
}
.bar { display: flex; align-items: center; justify-content: space-between; gap: 1rem; min-height: 3.75rem; }
.logo { font-weight: 700; font-size: 1.25rem; letter-spacing: -0.01em; color: var(--ink); text-decoration: none; }
nav { display: flex; align-items: center; gap: 1.25rem; }
nav a { color: var(--ink); text-decoration: none; }
nav a:hover { color: var(--accent); }

/* Кнопки */
.btn {
  display: inline-block; padding: 0.75rem 1.4rem;
  font: inherit; font-weight: 600; text-decoration: none; cursor: pointer;
  color: var(--accent-ink); background: var(--accent);
  border: 2px solid var(--accent); border-radius: 6px;
}
.btn:hover { filter: brightness(1.1); }
.btn.ghost { background: transparent; color: var(--accent); }
.btn.small { padding: 0.4rem 0.9rem; color: var(--accent-ink); }
nav a.btn:hover { color: var(--accent-ink); }

/* Главный экран */
.hero { padding: clamp(2.5rem, 7vw, 6rem) 0; }
.hero-grid { display: grid; gap: 3rem; grid-template-columns: 1.1fr 0.9fr; align-items: center; }
h1 { font-size: clamp(2rem, 4.6vw, 3.4rem); line-height: 1.1; letter-spacing: -0.025em; margin: 0 0 1.25rem; }
.lead { font-size: 1.2rem; color: var(--muted); max-width: 34rem; margin: 0 0 2rem; }
.actions { display: flex; flex-wrap: wrap; gap: 0.75rem; margin: 0; }

/* Панель мониторинга: главный визуальный элемент */
.panel {
  margin: 0; padding: 1.25rem;
  background: var(--surface);
  border: 1px solid var(--line); border-radius: 10px;
}
.panel figcaption { font-size: 0.9rem; color: var(--muted); margin-bottom: 1rem; }
.rows { list-style: none; margin: 0; padding: 0; display: grid; gap: 0.9rem; }
.rows li { display: grid; grid-template-columns: 5.5rem 1fr 3.8rem; align-items: center; gap: 0.75rem; font-family: var(--mono); font-size: 0.85rem; }
.rows .val { text-align: right; color: var(--muted); }
.bars { display: flex; gap: 2px; height: 1.6rem; }
.bars i { flex: 1; border-radius: 1.5px; background: var(--ok); }
.bars i.warn { background: var(--warn); }
.bars i.bad { background: var(--bad); }
.legend { margin: 1.1rem 0 0; font-size: 0.8rem; color: var(--muted); display: flex; flex-wrap: wrap; gap: 0.4rem 1rem; align-items: center; }
.legend i { display: inline-block; width: 0.7rem; height: 0.7rem; border-radius: 2px; margin-right: 0.3rem; vertical-align: -1px; }
.legend .ok { background: var(--ok); } .legend .warn { background: var(--warn); } .legend .bad { background: var(--bad); }

/* Блоки */
.block { padding: clamp(2.5rem, 6vw, 5rem) 0; }
.block.alt { background: var(--bg-alt); }
h2 { font-size: clamp(1.6rem, 3vw, 2.2rem); letter-spacing: -0.02em; margin: 0 0 1.75rem; line-height: 1.2; }
h3 { font-size: 1.15rem; margin: 0 0 0.5rem; line-height: 1.3; }
p { margin: 0 0 1rem; }

.cols { display: grid; gap: 1.5rem; grid-template-columns: repeat(3, 1fr); }
.cols article { border-top: 3px solid var(--accent); padding-top: 1rem; }
.cols p { color: var(--muted); }
.stack { margin-top: 2.5rem; padding: 1rem 1.25rem; background: var(--surface); border-left: 4px solid var(--accent); border-radius: 0 6px 6px 0; }

.steps { counter-reset: step; list-style: none; margin: 0; padding: 0; display: grid; gap: 1.5rem; grid-template-columns: repeat(3, 1fr); }
.steps li { counter-increment: step; position: relative; padding-left: 3rem; }
.steps li::before {
  content: counter(step);
  position: absolute; left: 0; top: 0;
  width: 2.2rem; height: 2.2rem; display: grid; place-items: center;
  font-weight: 700; color: var(--accent-ink); background: var(--accent); border-radius: 50%;
}
.steps p { color: var(--muted); }

/* FAQ */
details { border-bottom: 1px solid var(--line); padding: 1rem 0; }
summary { cursor: pointer; font-weight: 600; }
details p { margin: 0.75rem 0 0; color: var(--muted); }

/* Форма */
form { display: grid; gap: 1rem; margin-top: 1.5rem; }
label { display: grid; gap: 0.35rem; font-weight: 600; }
input, textarea {
  font: inherit; color: var(--ink); background: var(--surface);
  border: 1px solid var(--line); border-radius: 6px; padding: 0.7rem 0.85rem; width: 100%;
}
form .btn { justify-self: start; }
.note { color: var(--muted); margin: 0; min-height: 1.5em; }

/* Подвал */
.foot { border-top: 1px solid var(--line); color: var(--muted); font-size: 0.95rem; }
.foot a { color: var(--muted); }

/* Адаптив */
@media (max-width: 52rem) {
  .hero-grid, .cols, .steps { grid-template-columns: 1fr; }
  nav a:not(.btn) { display: none; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
}