@import url('https://cdn.jsdelivr.net/gh/orioncactus/pretendard@v1.3.9/dist/web/static/pretendard.css');
@import url('https://fonts.googleapis.com/css2?family=Fraunces:opsz,wght@9..144,400;9..144,500;9..144,600;9..144,700&family=JetBrains+Mono:wght@400;500;600&display=swap');

/* ============ Design tokens ============ */
:root{
  --ink:#16233F;
  --ink-soft:#4A5568;
  --paper:#F8F6F1;
  --paper-alt:#EFEAE0;
  --paper-deep:#E7E0D2;
  --grid-line:#D8DFE8;
  --line-on-ink:rgba(248,246,241,.14);
  --teal:#1F7A6C;
  --teal-soft:#E4F1EE;
  --amber:#C97A2B;
  --amber-soft:#FBEEDF;
  --white:#FFFFFF;
  --radius:14px;
  --radius-sm:8px;
  --shadow:0 1px 2px rgba(22,35,63,.06), 0 8px 24px -12px rgba(22,35,63,.18);
  --maxw:1120px;
  --font-body:'Pretendard', -apple-system, BlinkMacSystemFont, sans-serif;
  --font-display:'Fraunces', 'Pretendard', serif;
  --font-mono:'JetBrains Mono', ui-monospace, monospace;
}

*,*::before,*::after{box-sizing:border-box;}
html{scroll-behavior:smooth;}
@media (prefers-reduced-motion:reduce){html{scroll-behavior:auto;}
  *{animation-duration:.01ms !important; transition-duration:.01ms !important;}}

body{
  margin:0;
  font-family:var(--font-body);
  color:var(--ink);
  background:var(--paper);
  line-height:1.7;
  font-size:16px;
  -webkit-font-smoothing:antialiased;
}

img{max-width:100%; display:block;}
a{color:inherit;}
.container{max-width:var(--maxw); margin:0 auto; padding:0 24px;}

/* ============ Graph-paper texture ============ */
.grid-bg{
  background-image:
    linear-gradient(var(--grid-line) 1px, transparent 1px),
    linear-gradient(90deg, var(--grid-line) 1px, transparent 1px);
  background-size: 28px 28px;
  background-position: -1px -1px;
}
.grid-bg-ink{
  background-image:
    linear-gradient(var(--line-on-ink) 1px, transparent 1px),
    linear-gradient(90deg, var(--line-on-ink) 1px, transparent 1px);
  background-size: 28px 28px;
}

/* ============ Skip link / focus ============ */
.skip-link{
  position:absolute; left:-999px; top:0; background:var(--ink); color:var(--paper);
  padding:10px 16px; z-index:200; border-radius:0 0 8px 0;
}
.skip-link:focus{left:0;}
a:focus-visible, button:focus-visible, summary:focus-visible{
  outline:3px solid var(--amber); outline-offset:2px; border-radius:4px;
}

/* ============ Top notice bar ============ */
.notice-bar{
  background:var(--ink); color:var(--paper); font-size:13px; text-align:center;
  padding:8px 16px;
}
.notice-bar a{text-decoration:underline; color:var(--amber);}

/* ============ Nav ============ */
header.site-header{
  position:sticky; top:0; z-index:100;
  background:rgba(248,246,241,.92); backdrop-filter:blur(8px);
  border-bottom:1px solid var(--grid-line);
}
.nav-inner{
  display:flex; align-items:center; justify-content:space-between;
  padding:14px 24px; max-width:var(--maxw); margin:0 auto; gap:16px;
}
.brand{display:flex; align-items:center; gap:10px; text-decoration:none; color:var(--ink); font-weight:700; font-size:17px;}
.brand svg{width:34px; height:24px; flex-shrink:0;}
.brand small{display:block; font-weight:500; font-size:11px; color:var(--ink-soft); letter-spacing:.02em;}

nav.main-nav{display:flex; gap:2px; flex-wrap:wrap;}
nav.main-nav a{
  font-size:14px; font-weight:500; text-decoration:none; color:var(--ink-soft);
  padding:8px 12px; border-radius:8px; transition:background .15s,color .15s;
}
nav.main-nav a:hover, nav.main-nav a[aria-current="page"]{background:var(--paper-alt); color:var(--ink);}
.nav-toggle{display:none; background:none; border:1px solid var(--grid-line); border-radius:8px; padding:8px 10px; font-size:14px; cursor:pointer;}

@media (max-width:860px){
  nav.main-nav{
    display:none; position:absolute; top:100%; left:0; right:0; background:var(--paper);
    flex-direction:column; padding:12px 24px 20px; border-bottom:1px solid var(--grid-line); box-shadow:var(--shadow);
  }
  nav.main-nav.open{display:flex;}
  nav.main-nav a{padding:12px 8px; border-bottom:1px solid var(--grid-line);}
  .nav-toggle{display:inline-block;}
}

/* ============ Breadcrumb ============ */
.breadcrumb{font-size:13px; color:var(--ink-soft); padding:16px 0 0;}
.breadcrumb a{text-decoration:none; border-bottom:1px dotted var(--ink-soft);}
.breadcrumb .sep{margin:0 6px; opacity:.5;}

/* ============ Hero ============ */
.hero{padding:56px 0 48px; position:relative; overflow:hidden;}
.hero-eyebrow{
  display:inline-flex; align-items:center; gap:8px; font-family:var(--font-mono);
  font-size:12px; letter-spacing:.06em; text-transform:uppercase; color:var(--teal);
  background:var(--teal-soft); padding:6px 12px; border-radius:999px; margin-bottom:18px;
}
.hero h1{
  font-family:var(--font-display); font-weight:600; font-size:clamp(28px,4.4vw,46px);
  line-height:1.28; margin:0 0 18px; letter-spacing:-.01em;
}
.hero p.lead{font-size:18px; color:var(--ink-soft); max-width:62ch; margin:0 0 28px;}
.hero-meta{display:flex; gap:18px; flex-wrap:wrap; font-size:13px; color:var(--ink-soft); font-family:var(--font-mono);}

/* ============ Path badges (AB / BC signature device) ============ */
.badge{
  display:inline-flex; align-items:center; gap:6px; font-weight:700; font-size:13px;
  padding:4px 10px; border-radius:999px; font-family:var(--font-mono);
}
.badge-ab{background:var(--teal-soft); color:var(--teal);}
.badge-bc{background:var(--amber-soft); color:var(--amber);}
.badge::before{content:''; width:7px; height:7px; border-radius:50%; background:currentColor;}

/* ============ Sections ============ */
section{padding:52px 0;}
section.alt{background:var(--paper-alt);}
h2.section-title{
  font-family:var(--font-display); font-size:clamp(22px,3vw,30px); font-weight:600;
  margin:0 0 8px; letter-spacing:-.01em;
}
p.section-sub{color:var(--ink-soft); margin:0 0 30px; max-width:68ch;}

/* Divider curve motif */
.curve-divider{width:100%; height:56px; display:block; color:var(--grid-line);}

/* ============ Cards / grid ============ */
.grid-2{display:grid; grid-template-columns:1fr 1fr; gap:20px;}
.grid-3{display:grid; grid-template-columns:repeat(3,1fr); gap:20px;}
.grid-4{display:grid; grid-template-columns:repeat(4,1fr); gap:16px;}
@media (max-width:860px){.grid-2,.grid-3,.grid-4{grid-template-columns:1fr;}}

.card{
  background:var(--white); border:1px solid var(--grid-line); border-radius:var(--radius);
  padding:26px; box-shadow:var(--shadow);
}
.card h3{font-family:var(--font-display); font-size:19px; margin:0 0 10px; font-weight:600;}
.card p{color:var(--ink-soft); margin:0; font-size:15px;}
.card ul{margin:12px 0 0; padding-left:20px; color:var(--ink-soft); font-size:15px;}
.card ul li{margin-bottom:6px;}

.card-ab{border-top:4px solid var(--teal);}
.card-bc{border-top:4px solid var(--amber);}

/* stat callouts */
.stat{font-family:var(--font-display); font-size:38px; font-weight:600; color:var(--ink); line-height:1;}
.stat-label{font-size:13px; color:var(--ink-soft); margin-top:6px;}

/* ============ Table ============ */
.table-wrap{overflow-x:auto; border:1px solid var(--grid-line); border-radius:var(--radius); background:var(--white);}
table{width:100%; border-collapse:collapse; font-size:14.5px; min-width:560px;}
thead th{
  background:var(--ink); color:var(--paper); text-align:left; padding:12px 16px;
  font-weight:600; font-size:13px; position:sticky; top:0;
}
tbody td, tbody th{padding:12px 16px; border-bottom:1px solid var(--grid-line); text-align:left; vertical-align:top;}
tbody tr:last-child td{border-bottom:none;}
tbody tr:nth-child(even){background:var(--paper-alt);}
td.col-ab{color:var(--teal); font-weight:600;}
td.col-bc{color:var(--amber); font-weight:600;}

/* ============ Callout / warn box ============ */
.callout{
  border-radius:var(--radius); padding:20px 22px; border:1px solid var(--grid-line);
  background:var(--white); display:flex; gap:14px; align-items:flex-start;
}
.callout strong{display:block; margin-bottom:4px;}
.callout.teal{border-color:var(--teal); background:var(--teal-soft);}
.callout.amber{border-color:var(--amber); background:var(--amber-soft);}

/* ============ Timeline / steps ============ */
.steps{list-style:none; margin:0; padding:0; counter-reset:step;}
.steps li{
  counter-increment:step; position:relative; padding:0 0 28px 44px; border-left:2px solid var(--grid-line); margin-left:14px;
}
.steps li:last-child{border-left:2px solid transparent; padding-bottom:0;}
.steps li::before{
  content:counter(step); position:absolute; left:-15px; top:0; width:28px; height:28px;
  background:var(--ink); color:var(--paper); border-radius:50%; display:flex; align-items:center; justify-content:center;
  font-family:var(--font-mono); font-size:13px; font-weight:600;
}
.steps h3{margin:0 0 6px; font-family:var(--font-display); font-size:17px; font-weight:600;}
.steps p{margin:0; color:var(--ink-soft); font-size:15px;}

/* ============ FAQ ============ */
.faq-item{border-bottom:1px solid var(--grid-line); padding:18px 0;}
.faq-item summary{
  cursor:pointer; font-weight:600; font-size:16px; list-style:none; display:flex; justify-content:space-between; gap:16px;
}
.faq-item summary::-webkit-details-marker{display:none;}
.faq-item summary::after{content:'+'; font-family:var(--font-mono); font-size:20px; color:var(--ink-soft); flex-shrink:0;}
.faq-item[open] summary::after{content:'–';}
.faq-item p{color:var(--ink-soft); margin:12px 0 0; font-size:15px; max-width:70ch;}

/* ============ Quiz component ============ */
.quiz-box{background:var(--ink); color:var(--paper); border-radius:var(--radius); padding:32px; position:relative; overflow:hidden;}
.quiz-box h3{font-family:var(--font-display); font-size:22px; margin:0 0 6px;}
.quiz-box p.quiz-sub{color:#B9C2D6; margin:0 0 22px; font-size:14px;}
.quiz-q{font-weight:600; margin-bottom:14px; font-size:15px;}
.quiz-options{display:flex; flex-direction:column; gap:10px; margin-bottom:22px;}
.quiz-options button{
  text-align:left; background:rgba(248,246,241,.06); border:1px solid var(--line-on-ink); color:var(--paper);
  padding:12px 16px; border-radius:10px; cursor:pointer; font-size:14.5px; font-family:var(--font-body);
  transition:background .15s, border-color .15s;
}
.quiz-options button:hover{background:rgba(248,246,241,.14); border-color:var(--amber);}
.quiz-options button.selected{border-color:var(--amber); background:rgba(201,122,43,.22);}
#quizResult{display:none; background:rgba(248,246,241,.08); border-radius:10px; padding:18px 20px; margin-top:8px;}
#quizResult.show{display:block;}
#quizResult .result-badge{margin-bottom:8px;}
.quiz-progress{font-family:var(--font-mono); font-size:12px; color:#B9C2D6; margin-bottom:14px;}
.quiz-btn-row{display:flex; gap:10px; margin-top:6px;}
.btn{
  display:inline-flex; align-items:center; gap:8px; font-weight:600; font-size:14px; padding:10px 18px;
  border-radius:999px; text-decoration:none; border:1px solid transparent; cursor:pointer; font-family:var(--font-body);
}
.btn-primary{background:var(--amber); color:var(--white);}
.btn-primary:hover{background:#B5691F;}
.btn-ghost{background:transparent; border-color:var(--line-on-ink); color:var(--paper);}
.btn-ghost:hover{background:rgba(248,246,241,.08);}
.btn-outline{background:transparent; border-color:var(--ink); color:var(--ink);}

/* ============ CTA / link cards on homepage ============ */
.link-card{
  display:block; text-decoration:none; color:var(--ink); background:var(--white);
  border:1px solid var(--grid-line); border-radius:var(--radius); padding:22px; transition:transform .15s, box-shadow .15s;
}
.link-card:hover{transform:translateY(-2px); box-shadow:var(--shadow);}
.link-card .eyebrow{font-family:var(--font-mono); font-size:11px; text-transform:uppercase; letter-spacing:.06em; color:var(--ink-soft); display:block; margin-bottom:8px;}
.link-card h3{margin:0 0 8px; font-family:var(--font-display); font-size:18px;}
.link-card p{margin:0; font-size:14px; color:var(--ink-soft);}
.link-card .arrow{margin-top:14px; font-family:var(--font-mono); font-size:13px; color:var(--amber); font-weight:600;}

/* ============ Footer ============ */
footer.site-footer{background:var(--ink); color:#C9D2E4; padding:56px 0 28px; margin-top:40px;}
.footer-grid{display:grid; grid-template-columns:2fr 1fr 1fr 1fr; gap:32px; margin-bottom:36px;}
@media (max-width:760px){.footer-grid{grid-template-columns:1fr 1fr;}}
footer h4{color:var(--paper); font-size:13px; text-transform:uppercase; letter-spacing:.06em; margin:0 0 14px; font-family:var(--font-mono); font-weight:600;}
footer ul{list-style:none; margin:0; padding:0;}
footer li{margin-bottom:9px;}
footer a{color:#C9D2E4; text-decoration:none; font-size:14px;}
footer a:hover{color:var(--paper); text-decoration:underline;}
.footer-bottom{border-top:1px solid var(--line-on-ink); padding-top:22px; display:flex; justify-content:space-between; flex-wrap:wrap; gap:12px; font-size:12.5px; color:#8D98B3;}

/* ============ Utility ============ */
.mt-0{margin-top:0;} .mb-0{margin-bottom:0;}
.small{font-size:13px; color:var(--ink-soft);}
.center{text-align:center;}
.tag-row{display:flex; gap:8px; flex-wrap:wrap; margin:18px 0 0;}
.tag{font-family:var(--font-mono); font-size:12px; background:var(--paper-alt); border:1px solid var(--grid-line); padding:5px 10px; border-radius:999px; color:var(--ink-soft);}