:root {
  --bg: #fdfbf8;
  --bg-2: #f7f2ec;
  --bg-3: #efe8df;
  --ink: #17202c;
  --ink-2: #3f4a58;
  --ink-3: #6b7684;
  --line: #e6ded4;
  --primary: #f35262;
  --primary-dark: #d63f4f;
  --primary-soft: #fde7ea;
  --accent: #8edce9;
  --accent-soft: #e7f7fa;
  --accent-ink: #0f4c56;
  --radius: 16px;
  --nav: rgba(12, 19, 31, 0.88);
  --font-h: 'Fraunces', Georgia, 'Times New Roman', serif;
  --font-b: 'Inter Tight', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
}

* { box-sizing: border-box; }

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

body {
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  font-family: var(--font-b);
  font-size: 17px;
  line-height: 1.68;
  -webkit-font-smoothing: antialiased;
}

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

a { color: var(--primary-dark); text-decoration: none; }
a:hover { text-decoration: underline; }

h1, h2, h3, h4 {
  font-family: var(--font-h);
  font-weight: 600;
  letter-spacing: -0.015em;
  line-height: 1.18;
  margin: 0;
  color: var(--ink);
}

p { margin: 0 0 1em; }

.wrap {
  width: 100%;
  max-width: 1120px;
  margin: 0 auto;
  padding: 0 20px;
}

.skip {
  position: absolute;
  left: -9999px;
  top: 0;
  background: #fff;
  color: var(--ink);
  padding: 10px 14px;
  z-index: 200;
  border-radius: 8px;
}
.skip:focus { left: 12px; top: 12px; }

/* ---------- Navigation ---------- */
.nav {
  position: fixed;
  inset: 0 0 auto 0;
  z-index: 100;
  height: 60px;
  background: rgba(12, 19, 31, 0.94);
  border-bottom: 1px solid rgba(255, 255, 255, 0.1);
}

@supports ((backdrop-filter: blur(18px)) or (-webkit-backdrop-filter: blur(18px))) {
  .nav {
    background: var(--nav);
    backdrop-filter: blur(18px);
    -webkit-backdrop-filter: blur(18px);
  }
}

.nav-in {
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 14px;
  padding: 0 18px;
}

.brand {
  display: flex;
  align-items: center;
  gap: 10px;
  color: #fff;
  text-decoration: none;
  min-width: 0;
}
.brand:hover { text-decoration: none; }

.brand-mark {
  width: 30px;
  height: 30px;
  flex: 0 0 30px;
  border-radius: 8px;
  background: var(--primary);
  color: #fff;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 16px;
}

.brand-txt {
  font-family: var(--font-h);
  font-size: 15.5px;
  font-weight: 600;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.nav-links {
  display: none;
  align-items: center;
  gap: 2px;
  list-style: none;
  margin: 0;
  padding: 0;
}

.nav-links a,
.nav-drop-btn {
  display: inline-flex;
  align-items: center;
  gap: 5px;
  color: rgba(255, 255, 255, 0.84);
  font-size: 13.5px;
  font-weight: 500;
  padding: 8px 11px;
  border-radius: 6px;
  background: none;
  border: 0;
  cursor: pointer;
  font-family: var(--font-b);
  white-space: nowrap;
}

.nav-links a:hover,
.nav-drop-btn:hover,
.nav-drop-btn[aria-expanded="true"] {
  color: #fff;
  text-decoration: none;
  background: rgba(255, 255, 255, 0.08);
}

.nav-drop { position: relative; }

.nav-menu {
  position: absolute;
  top: calc(100% + 10px);
  left: 0;
  width: 400px;
  background: var(--bg);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 8px;
  display: none;
  grid-template-columns: 1fr 1fr;
  gap: 2px;
  box-shadow: 0 18px 40px rgba(23, 32, 44, 0.18);
}

.nav-menu.is-open { display: grid; }

.nav-menu a {
  color: var(--ink);
  font-size: 12.8px;
  padding: 8px 9px;
  border-radius: 6px;
  display: flex;
  align-items: center;
  gap: 6px;
}
.nav-menu a:hover { background: var(--primary-soft); color: var(--primary-dark); text-decoration: none; }

.nav-cta {
  display: none;
  background: var(--primary);
  color: #fff;
  font-size: 13px;
  font-weight: 600;
  padding: 9px 16px;
  border-radius: 8px;
  white-space: nowrap;
}
.nav-cta:hover { background: var(--primary-dark); text-decoration: none; color: #fff; }

@media (min-width: 900px) {
  .nav-links { display: flex; }
  .nav-cta { display: inline-block; }
}

/* ---------- Article header ---------- */
main { padding-top: 60px; }

.crumbs {
  max-width: 1120px;
  margin: 0 auto;
  padding: 16px 20px 0;
  font-size: 12px;
  color: var(--ink-3);
  display: flex;
  flex-wrap: wrap;
  gap: 7px;
  align-items: center;
}
.crumbs a { color: var(--ink-3); }
.crumbs a:hover { color: var(--primary-dark); }
.crumbs span[aria-current] { color: var(--ink-2); }

.a-head { padding: 18px 0 0; max-width: 860px; margin: 0 auto; }

.kicker {
  display: inline-block;
  font-size: 10.5px;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  font-weight: 700;
  color: var(--primary-dark);
  background: var(--primary-soft);
  padding: 5px 10px;
  border-radius: 999px;
  margin: 0 0 14px;
}

.a-head h1 {
  font-size: 30px;
  max-width: 860px;
}

@media (min-width: 768px) {
  .a-head h1 { font-size: 40px; }
}

.lead {
  margin: 14px 0 0;
  font-size: 16.5px;
  color: var(--ink-2);
  max-width: 70ch;
}

.meta {
  list-style: none;
  display: flex;
  flex-wrap: wrap;
  gap: 8px 16px;
  padding: 0;
  margin: 16px 0 0;
  font-size: 12px;
  color: var(--ink-3);
}
.meta li { display: flex; align-items: center; gap: 5px; }

.cover {
  margin: 20px 0 0;
  border-radius: var(--radius);
  overflow: hidden;
  background: var(--bg-2);
  border: 1px solid var(--line);
  max-width: 860px;
  margin-left: auto;
  margin-right: auto;
}
.cover img {
  width: 100%;
  height: 250px;
  object-fit: cover;
  object-position: top;
}
@media (min-width: 768px) {
  .cover img { height: 320px; }
}

/* ---------- Article body ---------- */
.article-body {
  max-width: 780px;
  margin: 0 auto;
  padding: 26px 0 0;
}

.article-body h2 {
  font-size: 23px;
  margin: 34px 0 12px;
  padding-top: 4px;
  scroll-margin-top: 80px;
}

.article-body h3 {
  font-size: 17.5px;
  margin: 24px 0 8px;
}

.article-body p,
.article-body li {
  color: var(--ink-2);
  font-size: 16.5px;
}

.article-body ul,
.article-body ol {
  margin: 0 0 1.1em;
  padding-left: 1.15em;
}

.article-body li { margin-bottom: 0.4em; }

.article-body strong { color: var(--ink); }

.toc {
  margin: 22px 0 6px;
  padding: 16px 18px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--bg-2);
}
.toc p {
  margin: 0 0 8px;
  font-size: 10.5px;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--ink-3);
  font-weight: 700;
}
.toc ol {
  margin: 0;
  padding-left: 1.1em;
  columns: 1;
}
@media (min-width: 640px) {
  .toc ol { columns: 2; column-gap: 24px; }
}
.toc li { font-size: 13.5px; margin-bottom: 4px; }
.toc a { color: var(--ink-2); }

.table-scroll {
  overflow-x: auto;
  margin: 18px 0 22px;
  border: 1px solid var(--line);
  border-radius: 12px;
}

table.data {
  width: 100%;
  min-width: 520px;
  border-collapse: collapse;
  font-size: 13.5px;
}

table.data caption {
  caption-side: top;
  text-align: left;
  padding: 10px 12px;
  font-size: 11.5px;
  color: var(--ink-3);
  background: var(--bg-2);
  border-bottom: 1px solid var(--line);
}

table.data th {
  background: var(--ink);
  color: #fff;
  text-align: left;
  font-size: 11px;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  font-weight: 600;
  padding: 9px 12px;
  white-space: nowrap;
}

table.data td {
  padding: 9px 12px;
  border-top: 1px solid var(--line);
  color: var(--ink-2);
  vertical-align: top;
}

table.data tbody tr:nth-child(even) td { background: var(--bg-2); }

.note, .warn {
  border-radius: 12px;
  padding: 13px 15px;
  margin: 18px 0 22px;
  font-size: 14.5px;
  line-height: 1.62;
  color: var(--ink-2);
}
.note { background: var(--accent-soft); border-left: 3px solid var(--accent); }
.warn { background: var(--primary-soft); border-left: 3px solid var(--primary); }
.note p:last-child, .warn p:last-child { margin: 0; }
.note strong, .warn strong { color: var(--ink); }

.checklist {
  list-style: none;
  padding: 0;
  margin: 0 0 20px;
  border: 1px solid var(--line);
  border-radius: 12px;
  overflow: hidden;
}
.checklist li {
  display: flex;
  gap: 10px;
  padding: 10px 13px;
  margin: 0;
  font-size: 14.5px;
  border-top: 1px solid var(--line);
  background: #fff;
}
.checklist li:first-child { border-top: 0; }
.checklist li::before {
  content: "";
  flex: 0 0 15px;
  width: 15px;
  height: 15px;
  margin-top: 4px;
  border: 1.5px solid var(--primary);
  border-radius: 3px;
}

.example {
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 16px 18px;
  background: #fff;
  margin: 18px 0 22px;
}
.example h3 { margin-top: 0; }
.example p { font-size: 14.5px; }
.example p:last-child { margin-bottom: 0; }
.example .exlabel {
  font-size: 10.5px;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--primary-dark);
  font-weight: 700;
  margin: 0 0 6px;
}

/* ---------- FAQ ---------- */
.faq-box {
  margin: 18px 0 8px;
  border: 1px solid var(--line);
  border-radius: 12px;
  overflow: hidden;
  background: #fff;
}
.faq-box details { border-top: 1px solid var(--line); }
.faq-box details:first-child { border-top: 0; }
.faq-box summary {
  cursor: pointer;
  padding: 12px 15px;
  font-size: 14.5px;
  font-weight: 600;
  color: var(--ink);
  list-style: none;
  display: flex;
  justify-content: space-between;
  gap: 12px;
}
.faq-box summary::-webkit-details-marker { display: none; }
.faq-box summary::after {
  content: "+";
  color: var(--primary-dark);
  font-size: 17px;
  line-height: 1;
}
.faq-box details[open] summary::after { content: "−"; }
.faq-box .ans { padding: 0 15px 13px; }
.faq-box .ans p { font-size: 14px; color: var(--ink-2); margin: 0; }

/* ---------- Related ---------- */
.related {
  margin: 34px 0 0;
  padding-top: 20px;
  border-top: 1px solid var(--line);
}
.related h2 { font-size: 18px; margin: 0 0 12px; }
.related ul {
  list-style: none;
  padding: 0;
  margin: 0;
  display: grid;
  gap: 8px;
}
@media (min-width: 700px) {
  .related ul { grid-template-columns: repeat(3, 1fr); }
}
.related a {
  display: block;
  border: 1px solid var(--line);
  border-radius: 12px;
  padding: 11px 13px;
  background: #fff;
  color: var(--ink);
  font-size: 13.2px;
  font-weight: 600;
  line-height: 1.45;
  height: 100%;
}
.related a:hover { border-color: var(--primary); color: var(--primary-dark); text-decoration: none; }
.related .rnum {
  display: block;
  font-size: 10.5px;
  letter-spacing: 0.14em;
  color: var(--ink-3);
  font-weight: 700;
  margin-bottom: 4px;
}

.back {
  margin: 26px 0 0;
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}
.back a {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-size: 13px;
  font-weight: 600;
  padding: 10px 16px;
  border-radius: 8px;
  border: 1px solid var(--line);
  color: var(--ink);
  background: #fff;
  white-space: nowrap;
}
.back a.primary { background: var(--primary); border-color: var(--primary); color: #fff; }
.back a:hover { text-decoration: none; border-color: var(--primary); color: var(--primary-dark); }
.back a.primary:hover { background: var(--primary-dark); color: #fff; }

/* ---------- Footer ---------- */
.site-foot {
  margin-top: 46px;
  background: var(--accent-soft);
  padding: 26px 0 92px;
}
.site-foot .wrap { max-width: 1120px; }
.foot-grid {
  display: grid;
  gap: 18px;
}
@media (min-width: 720px) {
  .foot-grid { grid-template-columns: 1.4fr 1fr; }
}
.foot-brand {
  font-family: var(--font-h);
  font-size: 16px;
  font-weight: 600;
  margin: 0 0 8px;
}
.site-foot p {
  font-size: 12px;
  line-height: 1.65;
  color: var(--ink-2);
  margin: 0 0 8px;
  max-width: 62ch;
}
.foot-links {
  list-style: none;
  padding: 0;
  margin: 0;
  display: flex;
  flex-wrap: wrap;
  gap: 6px 16px;
}
.foot-links a { font-size: 12.5px; color: var(--ink-2); }
.foot-bottom {
  margin-top: 16px;
  padding-top: 12px;
  border-top: 1px solid rgba(23, 32, 44, 0.12);
  font-size: 11.5px;
  color: var(--ink-3);
}

/* ---------- Mobile nav ---------- */
.mnav {
  position: fixed;
  inset: auto 0 0 0;
  z-index: 90;
  background: rgba(253, 251, 248, 0.96);
  border-top: 1px solid var(--line);
  padding-bottom: env(safe-area-inset-bottom);
}

@supports ((backdrop-filter: blur(12px)) or (-webkit-backdrop-filter: blur(12px))) {
  .mnav {
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
  }
}

.mnav ul {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  list-style: none;
  margin: 0;
  padding: 0;
}

.mnav a, .mnav button {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 2px;
  padding: 8px 0 9px;
  font-size: 10.5px;
  font-weight: 500;
  color: var(--ink-3);
  background: none;
  border: 0;
  cursor: pointer;
  font-family: var(--font-b);
  width: 100%;
}
.mnav a:hover, .mnav button:hover { text-decoration: none; color: var(--primary-dark); }
.mnav i { font-size: 19px; }

@media (min-width: 768px) {
  .mnav { display: none; }
  .site-foot { padding-bottom: 26px; }
}

.sheet {
  position: fixed;
  inset: 0;
  z-index: 110;
  display: none;
}
.sheet.is-open { display: block; }

.sheet-veil {
  position: absolute;
  inset: 0;
  background: rgba(23, 32, 44, 0.5);
  border: 0;
  padding: 0;
  width: 100%;
  cursor: pointer;
}

.sheet-panel {
  position: absolute;
  inset: auto 0 0 0;
  max-height: 84vh;
  overflow-y: auto;
  background: var(--bg);
  border-radius: 18px 18px 0 0;
  border-top: 1px solid var(--line);
  padding: 0 12px calc(env(safe-area-inset-bottom) + 14px);
}

.sheet-head {
  position: sticky;
  top: 0;
  background: var(--bg);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  padding: 13px 4px 11px;
  border-bottom: 1px solid var(--line);
}
.sheet-head strong { font-size: 14.5px; display: block; }
.sheet-head span { font-size: 11px; color: var(--ink-3); }
.sheet-close {
  width: 32px;
  height: 32px;
  border-radius: 8px;
  border: 1px solid var(--line);
  background: #fff;
  color: var(--ink);
  cursor: pointer;
  font-size: 16px;
}

.sheet-list {
  list-style: none;
  margin: 8px 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 5px;
}
.sheet-list a {
  display: flex;
  align-items: center;
  gap: 7px;
  padding: 10px;
  border: 1px solid var(--line);
  border-radius: 8px;
  font-size: 12.5px;
  font-weight: 500;
  color: var(--ink);
  background: #fff;
}
.sheet-list a:hover { border-color: var(--primary); text-decoration: none; }

.sheet-actions {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 6px;
  margin-top: 10px;
}
.sheet-actions a {
  text-align: center;
  padding: 10px;
  border-radius: 8px;
  font-size: 12.5px;
  font-weight: 600;
  border: 1px solid var(--line);
  color: var(--ink);
  background: #fff;
}
.sheet-actions a.p { background: var(--primary); border-color: var(--primary); color: #fff; }

a:focus-visible,
button:focus-visible,
summary:focus-visible {
  outline: 2px solid var(--primary);
  outline-offset: 2px;
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  * { transition-duration: 0.001ms !important; animation-duration: 0.001ms !important; }
}