:root {
  color-scheme: dark;
  --bg: #101419;
  --surface: #181f26;
  --surface-raised: #1d2730;
  --border: #2b3844;
  --text: #f4f7fa;
  --muted: #9eaebb;
  --accent: #3fbf9b;
  --accent-soft: rgba(63, 191, 155, 0.12);
  --warm: #f0b35b;
  --link: #8fc7ff;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
  scroll-padding-top: 104px;
}

body {
  min-width: 320px;
  margin: 0;
  font-family: "Segoe UI", Arial, sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.6;
}

a {
  color: var(--link);
  text-underline-offset: 3px;
}

a:hover,
a:focus-visible {
  color: #c4e2ff;
}

.site-header {
  position: sticky;
  z-index: 10;
  top: 0;
  border-bottom: 1px solid var(--border);
  background: rgba(16, 20, 25, 0.96);
  backdrop-filter: blur(12px);
}

.header-inner {
  width: min(1160px, calc(100% - 40px));
  min-height: 80px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  margin: 0 auto;
}

.brand {
  min-width: 0;
  display: flex;
  align-items: center;
  gap: 13px;
  color: var(--text);
  text-decoration: none;
}

.brand-avatar {
  width: 52px;
  height: 52px;
  flex: 0 0 auto;
  border: 2px solid #3a4b59;
  border-radius: 50%;
  object-fit: cover;
  box-shadow: 0 0 0 3px #10161c;
}

.brand strong,
.brand small {
  display: block;
}

.brand strong {
  font-size: 18px;
  line-height: 1.2;
}

.brand small {
  margin-top: 3px;
  color: var(--muted);
  font-size: 13px;
}

.button {
  min-height: 42px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0 16px;
  border: 1px solid var(--accent);
  border-radius: 8px;
  background: var(--accent-soft);
  color: var(--text);
  font-size: 14px;
  font-weight: 600;
  text-align: center;
  text-decoration: none;
}

.button:hover,
.button:focus-visible {
  background: rgba(63, 191, 155, 0.2);
  color: var(--text);
  outline: none;
}

main {
  width: min(1160px, calc(100% - 40px));
  margin: 0 auto;
}

.intro {
  padding: 76px 0 56px;
  border-bottom: 1px solid var(--border);
}

.eyebrow {
  margin: 0 0 6px;
  color: var(--accent);
  font-size: 13px;
  font-weight: 700;
  text-transform: uppercase;
}

h1,
h2,
h3,
p {
  overflow-wrap: anywhere;
}

h1 {
  max-width: 760px;
  margin: 0;
  font-size: clamp(36px, 6vw, 64px);
  line-height: 1.05;
}

.faq-title {
  color: var(--accent);
  font-size: 18px;
  line-height: 1.2;
  text-transform: uppercase;
}

.lead {
  max-width: 760px;
  margin: 24px 0 0;
  color: #dce5eb;
  font-size: 19px;
}

.contact {
  max-width: 760px;
  margin: 14px 0 0;
  color: var(--muted);
}

.content-layout {
  display: grid;
  grid-template-columns: 220px minmax(0, 1fr);
  gap: 72px;
  padding: 56px 0 88px;
}

.contents {
  position: sticky;
  top: 112px;
  align-self: start;
  display: grid;
  gap: 4px;
}

.contents p {
  margin: 0 0 10px;
  color: var(--muted);
  font-size: 12px;
  font-weight: 700;
  text-transform: uppercase;
}

.contents a {
  padding: 9px 12px;
  border-left: 2px solid var(--border);
  color: var(--muted);
  font-size: 14px;
  text-decoration: none;
}

.contents a:hover,
.contents a:focus-visible {
  border-color: var(--accent);
  color: var(--text);
  outline: none;
}

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

.faq-section {
  padding-bottom: 64px;
  border-bottom: 1px solid var(--border);
}

.faq-section + .faq-section {
  padding-top: 64px;
}

.section-heading {
  display: flex;
  align-items: flex-start;
  gap: 18px;
  margin-bottom: 28px;
}

.section-number {
  min-width: 42px;
  padding-top: 5px;
  color: var(--warm);
  font: 700 13px/1 "Consolas", monospace;
}

h2 {
  margin: 0;
  font-size: 30px;
  line-height: 1.2;
}

.feature-list {
  margin: 0;
  padding: 0;
  list-style: none;
  counter-reset: feature;
}

.feature-list li {
  position: relative;
  padding: 22px 0 22px 62px;
  border-top: 1px solid var(--border);
  counter-increment: feature;
}

.feature-list li::before {
  position: absolute;
  top: 23px;
  left: 0;
  width: 38px;
  height: 38px;
  display: grid;
  place-items: center;
  border: 1px solid var(--border);
  border-radius: 8px;
  background: var(--surface);
  color: var(--accent);
  content: counter(feature, decimal-leading-zero);
  font: 700 12px/1 "Consolas", monospace;
}

.feature-list h3 {
  margin: 0 0 6px;
  font-size: 18px;
}

.feature-list p,
.mode-grid p {
  margin: 0;
  color: var(--muted);
}

code {
  padding: 2px 6px;
  border: 1px solid var(--border);
  border-radius: 5px;
  background: #121920;
  color: #d8efff;
  font-family: "Consolas", monospace;
  font-size: 0.92em;
  overflow-wrap: anywhere;
}

.mode-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 16px;
}

.mode-grid article {
  min-height: 138px;
  padding: 22px;
  border: 1px solid var(--border);
  border-radius: 8px;
  background: var(--surface);
}

.mode-grid strong {
  display: block;
  margin-bottom: 8px;
  font-size: 18px;
}

.steps {
  margin: 0;
  padding-left: 24px;
}

.steps li {
  padding: 8px 0 8px 10px;
  color: var(--muted);
}

.steps li::marker {
  color: var(--accent);
  font-weight: 700;
}

.steps strong {
  color: var(--text);
}

footer {
  min-height: 90px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  width: min(1160px, calc(100% - 40px));
  margin: 0 auto;
  border-top: 1px solid var(--border);
  color: var(--muted);
  font-size: 14px;
}

@media (max-width: 820px) {
  .content-layout {
    grid-template-columns: 1fr;
    gap: 42px;
  }

  .contents {
    position: static;
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .contents p {
    grid-column: 1 / -1;
  }

  .contents a {
    border-bottom: 1px solid var(--border);
    border-left: 0;
  }

  .contents a:hover,
  .contents a:focus-visible {
    border-color: var(--accent);
  }
}

@media (max-width: 560px) {
  html {
    scroll-padding-top: 88px;
  }

  .header-inner,
  main,
  footer {
    width: min(100% - 28px, 1160px);
  }

  .header-inner {
    min-height: 72px;
  }

  .brand-avatar {
    width: 44px;
    height: 44px;
  }

  .brand small {
    display: none;
  }

  .button {
    max-width: 126px;
    min-height: 40px;
    padding: 6px 10px;
    line-height: 1.2;
  }

  .intro {
    padding: 52px 0 42px;
  }

  h1 {
    font-size: 40px;
  }

  .faq-title {
    font-size: 18px;
  }

  .lead {
    font-size: 17px;
  }

  .content-layout {
    padding: 40px 0 64px;
  }

  .contents {
    grid-template-columns: 1fr;
  }

  .section-heading {
    gap: 8px;
  }

  .section-number {
    min-width: 34px;
  }

  h2 {
    font-size: 25px;
  }

  .feature-list li {
    padding-left: 50px;
  }

  .feature-list li::before {
    width: 34px;
    height: 34px;
  }

  .mode-grid {
    grid-template-columns: 1fr;
  }

  footer {
    align-items: flex-start;
    flex-direction: column;
    justify-content: center;
    gap: 4px;
  }
}

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