:root {
  --c-bg: #ffffff;
  --c-surface: #fafafa;
  --c-surface-2: #f4f4f5;
  --c-border: #e5e7eb;
  --c-border-strong: #d4d4d8;
  --c-text: #111111;
  --c-text-soft: #4b5563;
  --c-text-muted: #6b7280;
  --c-brand: #e88c04;
  --c-brand-dark: #c2740a;
  --c-brand-soft: #fff4e0;
  --c-black: #000000;
  --c-focus: #1d4ed8;

  --radius-sm: 8px;
  --radius: 12px;
  --radius-lg: 16px;

  --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.04);
  --shadow: 0 4px 14px rgba(0, 0, 0, 0.06);
  --shadow-lg: 0 12px 32px rgba(0, 0, 0, 0.08);

  --container: 1100px;
  --container-narrow: 800px;

  --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto,
    "Helvetica Neue", Arial, "Noto Sans", sans-serif, "Apple Color Emoji",
    "Segoe UI Emoji";
}

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

html { -webkit-text-size-adjust: 100%; scroll-behavior: smooth; }

body {
  margin: 0;
  font-family: var(--font-sans);
  font-size: 16px;
  line-height: 1.6;
  color: var(--c-text);
  background: var(--c-bg);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  text-rendering: optimizeLegibility;
}

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

a {
  color: var(--c-text);
  text-decoration: none;
  transition: color 0.15s ease;
}

a:hover { color: var(--c-brand); }

button { font-family: inherit; cursor: pointer; }

h1, h2, h3, h4 {
  margin: 0 0 0.6em;
  line-height: 1.25;
  font-weight: 700;
  color: var(--c-black);
  letter-spacing: -0.01em;
}

h1 { font-size: clamp(1.7rem, 1.2rem + 2vw, 2.6rem); }
h2 { font-size: clamp(1.35rem, 1.05rem + 1.2vw, 1.8rem); }
h3 { font-size: 1.15rem; }

p { margin: 0 0 1em; color: var(--c-text-soft); }

.container {
  max-width: var(--container);
  margin: 0 auto;
  padding: 0 20px;
}

.container-narrow {
  max-width: var(--container-narrow);
  margin: 0 auto;
  padding: 0 20px;
}

.skip-link {
  position: absolute;
  left: -9999px;
  top: 0;
  background: var(--c-black);
  color: #fff;
  padding: 10px 14px;
  border-radius: 0 0 var(--radius-sm) 0;
  z-index: 999;
}
.skip-link:focus { left: 0; color: #fff; }

.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  background: rgba(255, 255, 255, 0.92);
  backdrop-filter: saturate(180%) blur(10px);
  -webkit-backdrop-filter: saturate(180%) blur(10px);
  border-bottom: 1px solid var(--c-border);
}

.site-header__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  min-height: 68px;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-weight: 700;
  color: var(--c-black);
}

.brand:hover { color: var(--c-black); }

.brand img {
  height: 32px;
  width: auto;
  margin-top: -3px;
}

.brand__suffix {
  font-size: 0.95rem;
  font-weight: 600;
  color: var(--c-text-muted);
  border-left: 1px solid var(--c-border-strong);
  padding-left: 10px;
  letter-spacing: 0.02em;
}

.header-nav {
  display: flex;
  align-items: center;
  gap: 8px;
}

.header-nav a {
  font-size: 0.92rem;
  color: var(--c-text-soft);
  padding: 8px 12px;
  border-radius: var(--radius-sm);
  font-weight: 500;
}
.header-nav a:hover { color: var(--c-black); background: var(--c-surface-2); }

.btn {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 9px 16px;
  border-radius: var(--radius-sm);
  font-weight: 600;
  font-size: 0.92rem;
  border: 1px solid transparent;
  transition: all 0.15s ease;
  cursor: pointer;
  text-align: center;
  justify-content: center;
}

.btn--primary {
  background: var(--c-black);
  color: #fff !important;
}
.btn--primary:hover { background: var(--c-brand); }

.btn--ghost {
  background: transparent;
  color: var(--c-text);
  border-color: var(--c-border-strong);
}
.btn--ghost:hover {
  background: var(--c-surface-2);
  border-color: var(--c-text-soft);
  color: var(--c-black);
}

.hero {
  padding: 60px 0 48px;
  text-align: center;
  background:
    radial-gradient(800px 280px at 50% -20%, rgba(232, 140, 4, 0.10), transparent 60%),
    var(--c-bg);
  border-bottom: 1px solid var(--c-border);
}

.hero h1 {
  margin-bottom: 12px;
}

.hero p {
  max-width: 620px;
  margin: 0 auto 28px;
  font-size: 1.05rem;
  color: var(--c-text-soft);
}

.section {
  padding: 56px 0;
}

.section--tight {
  padding: 40px 0;
}

.section__head {
  text-align: center;
  margin-bottom: 32px;
}

.section__eyebrow {
  display: inline-block;
  font-size: 0.78rem;
  color: var(--c-brand-dark);
  background: var(--c-brand-soft);
  padding: 4px 10px;
  border-radius: 999px;
  font-weight: 600;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  margin-bottom: 12px;
}

.cat-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 20px;
}

.cat-card {
  display: block;
  padding: 24px;
  background: #fff;
  border: 1px solid var(--c-border);
  border-radius: var(--radius-lg);
  transition: transform 0.18s ease, box-shadow 0.18s ease, border-color 0.18s ease;
  color: var(--c-text);
  height: 100%;
}

.cat-card:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow);
  border-color: var(--c-brand);
  color: var(--c-text);
}

.cat-card__icon {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 44px;
  height: 44px;
  background: var(--c-brand-soft);
  color: var(--c-brand-dark);
  border-radius: 10px;
  margin-bottom: 14px;
}

.cat-card h3 {
  font-size: 1.15rem;
  margin-bottom: 6px;
  color: var(--c-black);
}

.cat-card p {
  font-size: 0.94rem;
  margin-bottom: 12px;
  color: var(--c-text-muted);
}

.cat-card__count {
  font-size: 0.82rem;
  color: var(--c-brand-dark);
  font-weight: 600;
}

.article-list {
  list-style: none;
  padding: 0;
  margin: 0;
  display: grid;
  grid-template-columns: 1fr;
  gap: 10px;
}

.article-list__item {
  border: 1px solid var(--c-border);
  border-radius: var(--radius);
  background: #fff;
  transition: border-color 0.15s ease, transform 0.15s ease;
}

.article-list__item:hover {
  border-color: var(--c-brand);
}

.article-list__item a {
  display: flex;
  align-items: center;
  gap: 14px;
  padding: 16px 18px;
  color: var(--c-text);
}

.article-list__item a:hover { color: var(--c-text); }

.article-list__num {
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--c-brand-dark);
  background: var(--c-brand-soft);
  width: 28px;
  height: 28px;
  border-radius: 50%;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
}

.article-list__title {
  flex: 1;
  font-weight: 600;
  font-size: 1rem;
}

.article-list__arrow {
  color: var(--c-text-muted);
  transition: transform 0.15s ease;
}

.article-list__item:hover .article-list__arrow {
  color: var(--c-brand);
  transform: translateX(3px);
}

.breadcrumb {
  font-size: 0.88rem;
  color: var(--c-text-muted);
  padding: 20px 0 0;
}

.breadcrumb a { color: var(--c-text-muted); }
.breadcrumb a:hover { color: var(--c-brand); }
.breadcrumb__sep { margin: 0 8px; color: var(--c-border-strong); }

.article {
  padding: 24px 0 64px;
}

.article__head { margin-bottom: 28px; }

.article__category {
  font-size: 0.85rem;
  color: var(--c-brand-dark);
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  margin-bottom: 8px;
}

.article__title {
  font-size: clamp(1.6rem, 1.2rem + 1.6vw, 2.2rem);
  margin-bottom: 12px;
}

.article__lead {
  font-size: 1.05rem;
  color: var(--c-text-soft);
  margin-bottom: 0;
}

.prose h2 {
  margin-top: 2em;
  margin-bottom: 0.5em;
  font-size: 1.35rem;
  scroll-margin-top: 90px;
}

.prose h3 {
  margin-top: 1.6em;
  margin-bottom: 0.4em;
  font-size: 1.08rem;
  color: var(--c-black);
}

.prose p,
.prose li {
  font-size: 1rem;
  color: var(--c-text-soft);
  line-height: 1.7;
}

.prose strong { color: var(--c-black); }

.prose ul,
.prose ol {
  padding-left: 22px;
  margin: 0 0 1em;
}

.prose li { margin-bottom: 8px; }

.prose ol li::marker { color: var(--c-brand); font-weight: 700; }

.prose a {
  color: var(--c-brand-dark);
  text-decoration: underline;
  text-decoration-color: rgba(232, 140, 4, 0.4);
  text-underline-offset: 3px;
}

.prose a:hover { color: var(--c-brand); }

.prose img,
.prose .doc-img {
  border: 1px solid var(--c-border);
  border-radius: var(--radius);
  margin: 18px 0;
  width: 100%;
}

.doc-img--sm {
  max-width: 240px;
  margin-left: auto;
  margin-right: auto;
  display: block;
}

.doc-img--md {
  max-width: 420px;
  margin-left: auto;
  margin-right: auto;
  display: block;
}

.doc-img-row {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 14px;
  margin: 18px 0;
}

.doc-img-row .doc-img { margin: 0; }

.doc-img-row--sm {
  grid-template-columns: repeat(auto-fit, minmax(150px, 200px));
  justify-content: center;
}

.doc-img-row--sm .doc-img { width: 100%; }

.callout {
  margin: 22px 0;
  padding: 14px 16px;
  background: var(--c-brand-soft);
  border-left: 3px solid var(--c-brand);
  border-radius: var(--radius-sm);
  color: var(--c-text);
  font-size: 0.96rem;
}

.callout strong { color: var(--c-brand-dark); }

.article-nav {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 12px;
  margin-top: 40px;
  padding-top: 28px;
  border-top: 1px solid var(--c-border);
}

.article-nav a {
  display: block;
  padding: 16px;
  border: 1px solid var(--c-border);
  border-radius: var(--radius);
  background: #fff;
  transition: border-color 0.15s ease;
}

.article-nav a:hover { border-color: var(--c-brand); }

.article-nav__label {
  font-size: 0.78rem;
  color: var(--c-text-muted);
  margin-bottom: 4px;
  text-transform: uppercase;
  letter-spacing: 0.04em;
  font-weight: 600;
}

.article-nav__title {
  font-weight: 600;
  color: var(--c-black);
}

.article-nav__next { text-align: right; }

.support {
  background: var(--c-surface);
  border-top: 1px solid var(--c-border);
  border-bottom: 1px solid var(--c-border);
  padding: 56px 0;
  text-align: center;
}

.support h2 { margin-bottom: 10px; }

.support p {
  max-width: 540px;
  margin: 0 auto 22px;
  color: var(--c-text-soft);
}

.support__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  justify-content: center;
  align-items: center;
}

.support__actions a { min-width: 220px; }

.support__email {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-weight: 600;
  font-size: 1rem;
  color: var(--c-black);
  background: #fff;
  border: 1px solid var(--c-border-strong);
  padding: 9px 18px;
  border-radius: 999px;
  letter-spacing: 0.01em;
  user-select: text;
}

.support__email svg { color: var(--c-brand-dark); }

.site-footer {
  padding: 32px 0 36px;
  font-size: 0.9rem;
  color: var(--c-text-muted);
  background: #fff;
}

.site-footer__inner {
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 16px;
}

.site-footer a { color: var(--c-text-muted); }
.site-footer a:hover { color: var(--c-brand); }

.site-footer__nav { display: flex; gap: 18px; flex-wrap: wrap; }

@media (max-width: 720px) {
  .container,
  .container-narrow { padding: 0 16px; }

  .site-header__inner {
    flex-wrap: wrap;
    gap: 6px 10px;
    min-height: 0;
    padding-top: 8px;
    padding-bottom: 0;
  }

  .brand img { height: 28px; }
  .brand__suffix { display: none; }


  .site-header__back {
    margin-left: auto;
    border: none;
    background: transparent;
    padding: 4px 0;
    font-size: 0.85rem;
    font-weight: 600;
    color: var(--c-text-muted);
    letter-spacing: 0;
  }
  .site-header__back:hover {
    background: transparent;
    border: none;
    color: var(--c-brand);
  }
  .site-header__back-prefix { display: none; }
  .site-header__back::before {
    content: "\2190\00a0";
    color: inherit;
  }

  .header-nav {
    order: 3;
    width: 100%;
    justify-content: space-between;
    gap: 6px;
    padding: 6px 0 8px;
    margin-top: 4px;
    border-top: 1px solid var(--c-border);
  }

  .header-nav a {
    flex: 1 1 0;
    text-align: center;
    padding: 8px 4px;
    font-size: 0.86rem;
    border-radius: var(--radius-sm);
    background: var(--c-surface-2);
    color: var(--c-text);
    white-space: nowrap;
  }
  .header-nav a:hover {
    background: var(--c-brand-soft);
    color: var(--c-brand-dark);
  }

  .hero { padding: 36px 0 30px; }
  .hero p { font-size: 0.98rem; margin-bottom: 0; }

  .section { padding: 36px 0; }
  .section--tight { padding: 24px 0; }
  .section__head { margin-bottom: 22px; }

  .cat-grid { gap: 14px; }
  .cat-card { padding: 18px; }
  .cat-card__icon { width: 38px; height: 38px; margin-bottom: 10px; }

  .article-list__item a { padding: 14px 16px; gap: 12px; }
  .article-list__num { width: 26px; height: 26px; font-size: 0.78rem; }
  .article-list__title { font-size: 0.96rem; }

  .breadcrumb {
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    row-gap: 2px;
    font-size: 0.82rem;
    padding-top: 16px;
  }
  .breadcrumb__sep { margin: 0 6px; }

  .article { padding: 16px 0 44px; }
  .article__head { margin-bottom: 20px; }
  .article__lead { font-size: 0.98rem; }

  .prose h2 {
    margin-top: 1.6em;
    font-size: 1.2rem;
    scroll-margin-top: 110px;
  }
  .prose h3 { font-size: 1.02rem; }
  .prose ul, .prose ol { padding-left: 20px; }
  .prose img,
  .prose .doc-img { margin: 14px 0; }

  .doc-img-row {
    grid-template-columns: 1fr;
    gap: 10px;
  }
  .doc-img-row--sm { grid-template-columns: repeat(2, 1fr); }
  .doc-img--sm { max-width: 200px; }

  .article-nav {
    grid-template-columns: 1fr;
    gap: 10px;
    margin-top: 32px;
    padding-top: 22px;
  }
  .article-nav a { padding: 14px; }
  .article-nav__next { text-align: left; }

  .support { padding: 40px 0; }
  .support h2 { font-size: 1.3rem; }
  .support p { font-size: 0.96rem; }

  .support__actions {
    flex-direction: column;
    align-items: stretch;
    gap: 10px;
  }
  .support__actions a { min-width: 0; width: 100%; }
  .support__email {
    width: 100%;
    justify-content: center;
    padding: 10px 14px;
    font-size: 0.95rem;
    word-break: break-word;
  }

  .site-footer {
    padding: 26px 0 30px;
    text-align: center;
  }
  .site-footer__inner {
    flex-direction: column;
    align-items: center;
    gap: 12px;
  }
  .site-footer__nav { justify-content: center; gap: 22px; }
}

@media (max-width: 380px) {
  .container,
  .container-narrow { padding: 0 14px; }
  .brand img { height: 26px; }
  .header-nav { gap: 4px; }
  .header-nav a { padding: 7px 2px; font-size: 0.8rem; }
  .site-header__back { font-size: 0.8rem; }
  .doc-img-row--sm { grid-template-columns: 1fr; }
}

@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    transition: none !important;
    animation: none !important;
    scroll-behavior: auto !important;
  }
}

:focus-visible {
  outline: 3px solid rgba(232, 140, 4, 0.55);
  outline-offset: 2px;
  border-radius: 4px;
}