:root {
  color-scheme: light;
  --background: #eef3f7;
  --surface: #ffffff;
  --surface-soft: #f7fafc;
  --text: #24313d;
  --muted: #5f6f7d;
  --primary: #1769aa;
  --primary-dark: #0f4f82;
  --border: #d7e0e7;
  --success-bg: #eaf7ef;
  --success-border: #2e8b57;
  --warning-bg: #fff6dc;
  --warning-border: #d58b00;
  --danger-bg: #fff0f0;
  --danger-border: #c93f3f;
  --shadow: 0 8px 30px rgba(34, 58, 80, 0.08);
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  background: var(--background);
  color: var(--text);
  font-family: Arial, Helvetica, sans-serif;
  font-size: 17px;
  line-height: 1.65;
}

a {
  color: var(--primary);
}

a:hover {
  color: var(--primary-dark);
}

.page {
  width: min(1040px, calc(100% - 28px));
  margin: 28px auto 60px;
}

header,
main,
footer {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 14px;
  box-shadow: var(--shadow);
}

header {
  padding: clamp(24px, 5vw, 48px);
  margin-bottom: 20px;
}

main {
  padding: clamp(20px, 5vw, 48px);
}

footer {
  margin-top: 20px;
  padding: 20px 28px;
  color: var(--muted);
  font-size: 0.95rem;
}

h1,
h2,
h3 {
  line-height: 1.25;
  color: #20374a;
}

h1 {
  margin: 0 0 12px;
  font-size: clamp(2rem, 6vw, 3.2rem);
}

h2 {
  margin: 52px 0 18px;
  padding-bottom: 9px;
  border-bottom: 2px solid var(--border);
  font-size: clamp(1.45rem, 4vw, 2rem);
  scroll-margin-top: 18px;
}

h3 {
  margin: 30px 0 10px;
  font-size: 1.2rem;
  scroll-margin-top: 18px;
}

p {
  margin: 10px 0 16px;
}

ul,
ol {
  padding-left: 1.55rem;
}

li {
  margin: 8px 0;
}

code,
kbd {
  font-family: "Courier New", monospace;
  font-size: 0.92em;
}

code {
  padding: 2px 6px;
  background: #eaf0f4;
  border-radius: 4px;
}

kbd {
  display: inline-block;
  min-width: 1.8em;
  padding: 2px 7px;
  border: 1px solid #aebbc5;
  border-bottom-width: 3px;
  border-radius: 5px;
  background: #fff;
  color: #253746;
  text-align: center;
  white-space: nowrap;
}

pre {
  overflow-x: auto;
  padding: 16px;
  border-radius: 8px;
  background: #20374a;
  color: #f4f8fb;
  line-height: 1.5;
}

pre code {
  padding: 0;
  background: transparent;
  color: inherit;
}

table {
  width: 100%;
  margin: 18px 0 26px;
  border-collapse: collapse;
  font-size: 0.97rem;
}

th,
td {
  padding: 11px 12px;
  border: 1px solid var(--border);
  text-align: left;
  vertical-align: top;
}

th {
  background: #edf4f8;
}

.lead {
  max-width: 760px;
  margin-bottom: 22px;
  color: #415463;
  font-size: 1.14rem;
}

.meta {
  color: var(--muted);
  font-size: 0.95rem;
}

.app-link {
  display: inline-block;
  margin-top: 8px;
  padding: 10px 18px;
  border-radius: 8px;
  background: var(--primary);
  color: white;
  font-weight: bold;
  text-decoration: none;
}

.app-link:hover {
  background: var(--primary-dark);
  color: white;
}

.toc {
  margin: 28px 0 8px;
  padding: 22px 26px;
  border: 1px solid var(--border);
  border-radius: 10px;
  background: var(--surface-soft);
}

.toc h2 {
  margin: 0 0 12px;
  padding: 0;
  border: 0;
  font-size: 1.25rem;
}

.toc ol {
  columns: 2;
  column-gap: 44px;
  margin-bottom: 0;
}

.toc li {
  break-inside: avoid;
}

.box {
  margin: 20px 0;
  padding: 15px 18px;
  border-left: 5px solid var(--primary);
  border-radius: 5px;
  background: #eaf4fb;
}

.box p:last-child {
  margin-bottom: 0;
}

.tip {
  border-left-color: var(--success-border);
  background: var(--success-bg);
}

.warning {
  border-left-color: var(--warning-border);
  background: var(--warning-bg);
}

.danger {
  border-left-color: var(--danger-border);
  background: var(--danger-bg);
}

.steps {
  padding-left: 0;
  counter-reset: step;
  list-style: none;
}

.steps > li {
  position: relative;
  min-height: 44px;
  margin: 18px 0;
  padding-left: 58px;
  counter-increment: step;
}

.steps > li::before {
  position: absolute;
  top: 0;
  left: 0;
  width: 38px;
  height: 38px;
  border-radius: 50%;
  background: var(--primary);
  color: white;
  content: counter(step);
  font-weight: bold;
  line-height: 38px;
  text-align: center;
}

.path {
  font-weight: bold;
  color: #173f5f;
}

.term {
  padding: 15px 18px;
  border: 1px solid var(--border);
  border-radius: 8px;
  background: var(--surface-soft);
}

.term strong {
  color: #173f5f;
}

.small {
  color: var(--muted);
  font-size: 0.94rem;
}

.back-to-top {
  display: inline-block;
  margin-top: 12px;
  font-size: 0.92rem;
}

@media (max-width: 700px) {
  body {
    font-size: 16px;
  }

  .page {
    width: min(100% - 16px, 1040px);
    margin-top: 8px;
  }

  header,
  main,
  footer {
    border-radius: 9px;
  }

  .toc ol {
    columns: 1;
  }

  table {
    display: block;
    overflow-x: auto;
  }
}

@media print {
  body {
    background: white;
  }

  .page {
    width: 100%;
    margin: 0;
  }

  header,
  main,
  footer {
    border: 0;
    box-shadow: none;
  }

  .app-link,
  .back-to-top {
    display: none;
  }
}