:root {
  --page-bg: #f3f7f8;
  --surface: #ffffff;
  --surface-soft: #eefbfb;
  --text: #18252f;
  --muted: #63717d;
  --line: #dce7e9;
  --accent: #0f9fa6;
  --accent-dark: #08747a;
  --accent-light: #d7f5f5;
  --warning-bg: #fff9e9;
  --warning-line: #f1cc68;
  --shadow: 0 18px 45px rgba(30, 67, 74, .09);
  --radius: 18px;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
  background: var(--page-bg);
}

body {
  margin: 0;
  overflow-x: hidden;
  background:
    radial-gradient(circle at top left, rgba(55, 209, 215, .12), transparent 32rem),
    var(--page-bg);
  color: var(--text);
  font-family: "Roboto Slab", Georgia, "Times New Roman", serif;
  font-size: 17px;
  line-height: 1.75;
}

a {
  color: var(--accent-dark);
  text-decoration-thickness: 1px;
  text-underline-offset: 3px;
}

img {
  max-width: 100%;
  height: auto;
}

.screen-reader-text {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

.skip-link:focus {
  top: 12px;
  left: 12px;
  z-index: 100;
  width: auto;
  height: auto;
  padding: 10px 14px;
  clip: auto;
  border-radius: 8px;
  background: #fff;
}

.fixed {
  width: min(1180px, calc(100% - 40px));
  margin-inline: auto;
}

.site-header {
  margin-bottom: 34px;
  padding: 13px 0;
  border-bottom: 1px solid rgba(15, 159, 166, .14);
  background: rgba(255, 255, 255, .96);
  box-shadow: 0 8px 28px rgba(30, 67, 74, .06);
}

.site-header-inner {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 28px;
}

.site-branding {
  display: flex;
  align-items: center;
  gap: 12px;
  color: #12363d;
  text-decoration: none;
}

.site-branding img {
  display: block;
  width: 70px;
  height: 70px;
  object-fit: contain;
}

.site-branding__text {
  display: grid;
  line-height: 1.15;
}

.site-branding__name {
  font-size: 19px;
  font-weight: 700;
}

.site-branding__tagline {
  margin-top: 5px;
  color: var(--muted);
  font-family: Arial, sans-serif;
  font-size: 12px;
  font-weight: 400;
}

.top-menu ul {
  display: flex;
  flex-wrap: wrap;
  justify-content: flex-end;
  gap: 5px;
  margin: 0;
  padding: 0;
  list-style: none;
}

.top-menu a {
  display: block;
  padding: 9px 12px;
  border-radius: 10px;
  color: #31434d;
  font-family: Arial, sans-serif;
  font-size: 13px;
  font-weight: 700;
  text-decoration: none;
}

.top-menu a:hover,
.top-menu a:focus,
.top-menu a[aria-current="page"] {
  background: var(--accent-light);
  color: var(--accent-dark);
}

.nav-actions {
  display: flex;
  flex: 0 0 auto;
  align-items: center;
  gap: 10px;
}

.nav-action {
  display: inline-flex;
  min-height: 44px;
  min-width: 108px;
  align-items: center;
  justify-content: center;
  padding: 10px 18px;
  border: 2px solid transparent;
  border-radius: 12px;
  font-family: Arial, sans-serif;
  font-size: 13px;
  font-weight: 800;
  line-height: 1;
  letter-spacing: .04em;
  text-decoration: none;
  box-shadow: 0 8px 18px rgba(18, 54, 61, .16);
  transition: transform .18s ease, box-shadow .18s ease, background-color .18s ease;
}

.nav-action--brand {
  border-color: #12363d;
  background: #12363d;
  color: #ffffff;
}

.nav-action--register {
  border-color: #d9a900;
  background: #ffd54a;
  color: #102b32;
}

.nav-action:hover {
  transform: translateY(-2px);
  box-shadow: 0 11px 24px rgba(18, 54, 61, .24);
}

.nav-action--brand:hover {
  background: #0a262c;
  color: #ffffff;
}

.nav-action--register:hover {
  background: #ffe174;
  color: #102b32;
}

.nav-action:focus-visible {
  outline: 3px solid #37d1d7;
  outline-offset: 3px;
}

.nav-action:active {
  transform: translateY(0);
  box-shadow: 0 5px 12px rgba(18, 54, 61, .2);
}

.site-content {
  padding-bottom: 52px;
}

.site-content-inner {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 300px;
  align-items: start;
  gap: 38px;
}

.content-area {
  min-width: 0;
}

.site-main {
  padding: clamp(26px, 4vw, 48px);
  border: 1px solid rgba(220, 231, 233, .9);
  border-radius: var(--radius);
  background: var(--surface);
  box-shadow: var(--shadow);
}

.breadcrumb {
  margin-bottom: 16px;
  color: var(--muted);
  font-family: Arial, sans-serif;
  font-size: 13px;
}

.breadcrumb a {
  text-decoration: none;
}

.entry-title {
  max-width: 850px;
  margin: 0 0 18px;
  color: #102b32;
  font-size: clamp(31px, 4.1vw, 48px);
  line-height: 1.14;
  letter-spacing: -.035em;
}

.entry-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 8px 18px;
  margin-bottom: 25px;
  color: var(--muted);
  font-family: Arial, sans-serif;
  font-size: 13px;
}

.entry-lead {
  margin: 0 0 24px;
  color: #29414a;
  font-size: 19px;
  line-height: 1.7;
}

.notice {
  margin: 26px 0;
  padding: 17px 19px;
  border: 1px solid var(--warning-line);
  border-left-width: 5px;
  border-radius: 12px;
  background: var(--warning-bg);
  color: #5c4b18;
}

.notice strong {
  color: #473900;
}

.table-of-contents {
  margin: 28px 0 32px;
  padding: 20px 22px;
  border: 1px solid #bfe4e6;
  border-radius: 15px;
  background: linear-gradient(135deg, #f3ffff, #eaf8f8);
}

.table-of-contents__title {
  margin: 0 0 12px;
  color: #153e45;
  font-size: 18px;
}

.table-of-contents ol {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 8px 22px;
  margin: 0;
  padding: 0;
  list-style: none;
}

.table-of-contents a {
  display: block;
  padding: 7px 9px;
  border-radius: 8px;
  color: #28515a;
  font-family: Arial, sans-serif;
  font-size: 14px;
  line-height: 1.45;
  text-decoration: none;
}

.table-of-contents a:hover,
.table-of-contents a:focus {
  background: rgba(15, 159, 166, .1);
  color: var(--accent-dark);
}

.entry-content {
  color: #2e3d47;
}

.entry-content p {
  margin: 0 0 1.25em;
}

.entry-content h2 {
  margin: 2.15em 0 .8em;
  padding-bottom: 12px;
  border-bottom: 2px solid var(--accent-light);
  color: #14343b;
  font-size: clamp(26px, 3vw, 35px);
  line-height: 1.25;
}

.entry-content h3 {
  margin: 1.8em 0 .65em;
  color: var(--accent-dark);
  font-size: clamp(21px, 2.2vw, 27px);
  line-height: 1.3;
}

.entry-content ul,
.entry-content ol {
  margin: 0 0 1.35em;
  padding-left: 1.35em;
}

.entry-content li {
  margin-bottom: .55em;
  padding-left: .2em;
}

.feature-grid,
.step-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 14px;
  margin: 22px 0 30px;
}

.feature-card,
.step-card {
  padding: 18px;
  border: 1px solid var(--line);
  border-radius: 14px;
  background: #f9fbfb;
}

.feature-card h3,
.step-card h3 {
  margin: 0 0 8px;
  color: #153e45;
  font-size: 18px;
}

.feature-card p,
.step-card p {
  margin: 0;
  color: #53636d;
  font-family: Arial, sans-serif;
  font-size: 14px;
  line-height: 1.6;
}

.step-card__number {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 30px;
  height: 30px;
  margin-bottom: 11px;
  border-radius: 50%;
  background: var(--accent-light);
  color: var(--accent-dark);
  font-family: Arial, sans-serif;
  font-size: 13px;
  font-weight: 700;
}

.checklist {
  padding: 20px 22px;
  border: 1px solid var(--line);
  border-radius: 14px;
  background: #f9fbfb;
}

.checklist li::marker {
  color: var(--accent);
}

.related-links {
  margin-top: 38px;
  padding: 22px;
  border-radius: 15px;
  background: #eef8f8;
}

.related-links h2 {
  margin: 0 0 13px;
  padding: 0;
  border: 0;
  font-size: 22px;
}

.related-links ul {
  margin-bottom: 0;
}

.widget-area {
  min-width: 0;
}

.sticky-sidebar {
  position: sticky;
  top: 24px;
}

.widget {
  overflow: hidden;
  margin-bottom: 22px;
  padding: 21px;
  border: 1px solid var(--line);
  border-radius: 15px;
  background: var(--surface);
  box-shadow: 0 12px 32px rgba(30, 67, 74, .07);
}

.widget-title {
  margin: 0 0 14px;
  padding-bottom: 12px;
  border-bottom: 2px solid var(--accent-light);
  color: #153840;
  font-size: 18px;
}

.widget p {
  color: var(--muted);
  font-family: Arial, sans-serif;
  font-size: 14px;
  line-height: 1.65;
}

.sidebar-links {
  margin: 0;
  padding: 0;
  list-style: none;
}

.sidebar-links li + li {
  border-top: 1px solid #e7eeef;
}

.sidebar-links a {
  display: block;
  padding: 12px 0;
  color: #233943;
  font-family: Arial, sans-serif;
  font-size: 14px;
  font-weight: 700;
  line-height: 1.45;
  text-decoration: none;
}

.sidebar-links a:hover,
.sidebar-links a:focus {
  color: var(--accent-dark);
}

.sidebar-image {
  display: block;
  overflow: hidden;
  margin: -21px -21px 17px;
}

.sidebar-image img {
  display: block;
  width: 100%;
  aspect-ratio: 16 / 10;
  object-fit: cover;
}

.site-footer {
  padding: 28px 0;
  background: #12363d;
  color: #e7f6f7;
}

.footer-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
}

.footer-inner p {
  margin: 0;
  font-family: Arial, sans-serif;
  font-size: 13px;
}

.footer-nav {
  display: flex;
  flex-wrap: wrap;
  gap: 14px;
}

.footer-nav a {
  color: #e7f6f7;
  font-family: Arial, sans-serif;
  font-size: 13px;
  text-decoration: none;
}

@media (max-width: 980px) {
  .site-content-inner {
    grid-template-columns: minmax(0, 1fr);
  }

  .sticky-sidebar {
    position: static;
    display: grid;
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 20px;
  }

  .widget {
    margin: 0;
  }
}

@media (max-width: 760px) {
  .fixed {
    width: min(100% - 28px, 1180px);
  }

  .site-header {
    margin-bottom: 20px;
  }

  .site-header-inner,
  .footer-inner {
    align-items: flex-start;
    flex-direction: column;
  }

  .site-branding img {
    width: 58px;
    height: 58px;
  }

  .top-menu {
    width: 100%;
    overflow-x: auto;
  }

  .top-menu ul {
    justify-content: flex-start;
    flex-wrap: nowrap;
    width: max-content;
    padding-bottom: 3px;
  }

  .nav-actions {
    width: 100%;
  }

  .nav-action {
    flex: 1 1 0;
  }

  .site-main {
    padding: 24px 19px;
    border-radius: 14px;
  }

  .entry-title {
    font-size: clamp(29px, 9vw, 39px);
  }

  .table-of-contents,
  .notice {
    padding: 18px;
  }

  .table-of-contents ol,
  .feature-grid,
  .step-grid,
  .sticky-sidebar {
    grid-template-columns: minmax(0, 1fr);
  }
}

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