@import url('https://fonts.googleapis.com/css2?family=Noto+Sans+KR:wght@300;400;500;700&display=swap');

:root{
  --ink:#000000;
  --paper:#ffffff;
  --soft:#6d6d6d;
  --hair:#d9d9d9;
}

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

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

body{
  margin:0;
  background:var(--paper);
  color:var(--ink);
  font-family:"Noto Sans KR","PingFang SC","Hiragino Sans GB","Microsoft YaHei",system-ui,sans-serif;
  font-size:17px;
  line-height:1.75;
  font-weight:400;
  overflow-x:hidden;
}

a{color:inherit;text-decoration:none}
img{max-width:100%;display:block}
p{margin:0 0 1em}

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

/* ---------- 报头 ---------- */
.masthead{
  display:grid;
  grid-template-columns:1fr auto 1fr;
  align-items:center;
  gap:8px;
  padding:12px clamp(12px,3vw,28px);
  border-bottom:3px solid var(--ink);
}

.brand{
  justify-self:center;
  font-size:clamp(17px,4.4vw,22px);
  font-weight:700;
  letter-spacing:.22em;
  padding:8px 12px;
  border-left:2px solid var(--ink);
  border-right:2px solid var(--ink);
  text-align:center;
  white-space:nowrap;
}

.nav-drawer{position:relative}
.nav-drawer--l{justify-self:start}
.nav-drawer--r{justify-self:end}

.nav-drawer > summary{
  list-style:none;
  cursor:pointer;
  display:inline-flex;
  align-items:center;
  gap:8px;
  min-height:44px;
  padding:6px 12px;
  border:2px solid var(--ink);
  font-size:16px;
  letter-spacing:.12em;
  background:var(--paper);
}
.nav-drawer > summary::-webkit-details-marker{display:none}
.nav-drawer[open] > summary{background:var(--ink);color:var(--paper)}

.bars{
  display:block;
  width:16px;
  height:11px;
  position:relative;
  border-top:2px solid currentColor;
  border-bottom:2px solid currentColor;
}
.bars::after{
  content:"";
  position:absolute;
  left:0;right:0;
  top:3px;
  border-top:2px solid currentColor;
}

.nav-drawer menu{
  position:absolute;
  top:calc(100% + 10px);
  left:0;
  z-index:60;
  margin:0;
  padding:6px;
  list-style:none;
  min-width:176px;
  background:var(--paper);
  border:2px solid var(--ink);
  box-shadow:6px 6px 0 var(--ink);
}
.nav-drawer--r menu{left:auto;right:0}

.nav-drawer menu a{
  display:flex;
  align-items:center;
  gap:10px;
  min-height:44px;
  padding:6px 10px;
  font-size:16px;
  border-bottom:1px solid var(--hair);
}
.nav-drawer menu li:last-child a{border-bottom:0}
.nav-drawer menu a:hover{background:var(--ink);color:var(--paper)}

.dot{
  display:block;
  flex:0 0 7px;
  width:7px;
  height:7px;
  background:currentColor;
}

/* ---------- 首屏 ---------- */
.hero{
  position:relative;
  margin:0;
  height:70vh;
  min-height:400px;
  display:grid;
  place-items:center;
  overflow:hidden;
  background:#0b0b0b;
  color:var(--paper);
  clip-path:polygon(0 0,100% 0,100% 100%,0 calc(100% - 56px));
}

.hero-media{
  position:absolute;
  inset:-20% 0;
  z-index:0;
  will-change:transform;
}
.hero-img{
  width:100%;
  height:100%;
  object-fit:cover;
  opacity:.52;
  filter:grayscale(1) contrast(1.12);
}

.hero-inner{
  position:relative;
  z-index:1;
  margin:0;
  text-align:center;
  padding:24px clamp(16px,5vw,40px);
  animation:rise .85s cubic-bezier(.2,.7,.2,1) both .08s;
}

@keyframes rise{
  from{opacity:0;transform:translateY(18px)}
  to{opacity:1;transform:none}
}

.badge{
  display:inline-block;
  margin:0 0 18px;
  padding:6px 15px;
  border:2px solid currentColor;
  font-size:16px;
  letter-spacing:.3em;
  line-height:1.5;
}

.hero h1{
  margin:0 auto;
  max-width:16em;
  font-size:clamp(28px,7.4vw,66px);
  line-height:1.1;
  font-weight:700;
  letter-spacing:-.02em;
}

/* ---------- 页码条 ---------- */
.rail{
  position:sticky;
  top:0;
  z-index:30;
  display:flex;
  overflow-x:auto;
  background:var(--ink);
  color:var(--paper);
  border-bottom:3px solid var(--ink);
  overscroll-behavior-x:contain;
}
.rail a{
  display:flex;
  align-items:center;
  gap:9px;
  min-height:44px;
  padding:10px 15px;
  white-space:nowrap;
  font-size:16px;
  letter-spacing:.04em;
  border-right:1px solid rgba(255,255,255,.3);
}
.rail b{
  font-weight:400;
  opacity:.62;
  letter-spacing:.1em;
}
.rail a:hover{background:var(--paper);color:var(--ink)}

/* ---------- 版面骨架 ---------- */
.page{
  display:grid;
  grid-template-columns:190px minmax(0,1fr);
  gap:clamp(24px,4vw,56px);
  max-width:1180px;
  margin:0 auto;
  padding:clamp(28px,4vw,52px) clamp(16px,4vw,40px) 0;
}

.side{
  position:sticky;
  top:58px;
  align-self:start;
  border-top:3px solid var(--ink);
  padding-top:10px;
}

.side-h{
  margin:0 0 10px;
  font-size:16px;
  font-weight:700;
  letter-spacing:.28em;
}

.toc{
  list-style:none;
  margin:0;
  padding:0;
  counter-reset:toc;
}
.toc li{
  display:flex;
  align-items:baseline;
  border-bottom:1px solid var(--hair);
  counter-increment:toc;
}
.toc li::before{
  content:counter(toc,decimal-leading-zero);
  flex:0 0 2.4em;
  font-size:16px;
  opacity:.45;
  letter-spacing:.08em;
}
.toc a{
  display:flex;
  align-items:center;
  flex:1 1 auto;
  min-height:42px;
  padding:6px 0;
  font-size:16px;
}
.toc a:hover{text-decoration:underline;text-underline-offset:4px}

/* ---------- 正文 ---------- */
.sheet{
  min-width:0;
  counter-reset:sec;
}

.sheet > div{
  position:relative;
  border-top:3px solid var(--ink);
  padding:34px 0 30px;
  counter-increment:sec;
  scroll-margin-top:70px;
}
.sheet > div::before{
  content:counter(sec,decimal-leading-zero);
  position:absolute;
  top:-14px;
  left:0;
  padding:0 9px;
  background:var(--ink);
  color:var(--paper);
  font-size:16px;
  line-height:1.5;
  letter-spacing:.12em;
}

.sheet h2{
  margin:14px 0 16px;
  font-size:clamp(23px,3.6vw,36px);
  line-height:1.18;
  font-weight:700;
  letter-spacing:-.01em;
}
.sheet h2 > span,
.sheet h3 > span{display:inline}

.sheet h3{
  margin:26px 0 10px;
  font-size:clamp(19px,2.6vw,24px);
  line-height:1.3;
  font-weight:700;
}

.sheet p{max-width:64ch;margin:0 0 1.1em;line-height:1.85}
.sheet a{text-decoration:underline;text-underline-offset:3px}
.sheet a:hover{text-decoration-thickness:2px}

.sheet ul,
.sheet ol{margin:0 0 1.2em;padding-left:1.2em}
.sheet li{margin-bottom:.5em;line-height:1.8}

.sheet blockquote{
  margin:26px 0;
  padding:6px 0 6px 20px;
  border-left:8px solid var(--ink);
  font-size:21px;
  font-weight:500;
  line-height:1.6;
}
.sheet blockquote p{margin:0}

.sheet figure{margin:26px 0}
.sheet figcaption{
  margin-top:8px;
  padding-top:8px;
  border-top:1px solid var(--hair);
  font-size:16px;
  color:var(--soft);
}

.sheet img{width:100%;height:auto}

.sheet table{
  width:100%;
  border-collapse:collapse;
  margin:22px 0;
  font-size:16px;
}
.sheet th,
.sheet td{
  padding:10px 8px;
  text-align:left;
  border-bottom:1px solid var(--hair);
  vertical-align:top;
}
.sheet th{border-bottom:2px solid var(--ink);font-weight:700}

.sheet hr{border:0;border-top:1px solid var(--hair);margin:26px 0}

@media (min-width:1024px){
  .sheet > div{
    columns:2;
    column-gap:52px;
    column-rule:1px solid var(--hair);
  }
  .sheet > div > h2,
  .sheet > div > h3,
  .sheet > div > figure,
  .sheet > div > blockquote,
  .sheet > div > table,
  .sheet > div > hr{column-span:all}
  .sheet > div > p:first-of-type::first-letter{
    float:left;
    padding:4px 10px 0 0;
    font-size:3.2em;
    line-height:.82;
    font-weight:700;
  }
}

/* ---------- 页脚 ---------- */
.colophon{
  margin-top:clamp(40px,6vw,72px);
  border-top:6px solid var(--ink);
}

.cta{
  padding:clamp(36px,7vw,64px) 20px;
  text-align:center;
  border-bottom:3px solid var(--ink);
}
.cta-h{
  margin:0 0 18px;
  font-size:clamp(26px,6vw,54px);
  line-height:1.1;
  font-weight:700;
  letter-spacing:-.02em;
}
.cta-btn{
  display:inline-flex;
  align-items:center;
  justify-content:center;
  min-height:48px;
  padding:0 28px;
  border:2px solid var(--ink);
  background:var(--ink);
  color:var(--paper);
  font-size:16px;
  letter-spacing:.2em;
}
.cta-btn:hover{background:var(--paper);color:var(--ink)}

.cols{
  display:grid;
  grid-template-columns:repeat(3,1fr);
  border-bottom:3px solid var(--ink);
}
.cols dl{
  margin:0;
  padding:26px 20px;
  border-right:1px solid var(--ink);
}
.cols dl:last-child{border-right:0}
.cols dt{
  padding-bottom:8px;
  margin-bottom:10px;
  border-bottom:3px solid var(--ink);
  font-size:22px;
  font-weight:700;
  letter-spacing:.1em;
}
.cols dd{margin:0}
.cols dd a{
  display:flex;
  align-items:center;
  min-height:44px;
  font-size:16px;
  border-bottom:1px solid var(--hair);
}
.cols dd:last-child a{border-bottom:0}
.cols dd a:hover{text-decoration:underline;text-underline-offset:4px}

.foot-base{
  display:flex;
  flex-wrap:wrap;
  justify-content:center;
  align-items:center;
  gap:16px;
  padding:18px 16px 26px;
  font-size:16px;
  letter-spacing:.08em;
}
.foot-base p{margin:0}

/* ---------- 入场 ---------- */
html.js .reveal{
  opacity:0;
  transform:translateY(18px);
  transition:opacity .7s ease,transform .7s cubic-bezier(.2,.7,.2,1);
}
html.js .reveal.in{opacity:1;transform:none}
@media (prefers-reduced-motion: reduce){
  html.js .reveal{opacity:1;transform:none}
}

/* ---------- 小屏 ---------- */
@media (max-width:760px){
  .nav-drawer .st{display:none}
  .nav-drawer > summary{padding:6px 12px}
  .brand{letter-spacing:.16em}

  .hero{
    height:62vh;
    min-height:330px;
    clip-path:polygon(0 0,100% 0,100% 100%,0 calc(100% - 34px));
  }

  .page{
    grid-template-columns:1fr;
    gap:10px;
    padding-top:22px;
  }
  .side{position:static;top:auto}
  .toc{display:grid;grid-template-columns:1fr 1fr;column-gap:18px}
  .toc li::before{flex:0 0 2.2em}

  .sheet > div{padding:30px 0 24px;scroll-margin-top:64px}

  .cols{grid-template-columns:1fr}
  .cols dl{border-right:0;border-bottom:1px solid var(--ink)}
  .cols dl:last-child{border-bottom:0}
}

@media (max-width:400px){
  body{font-size:16px}
  .rail a{padding:10px 12px}
  .badge{letter-spacing:.2em}
}

button[aria-expanded]{min-width:44px;min-height:44px}